HarfBuzz: Update to version 2.8.0

119 files changed, 3849 insertions, 3156 deletions

diff --git a/thirdparty/harfbuzz/NEWS b/thirdparty/harfbuzz/NEWS
index f09c2fafd1..321c550188 100644
--- a/thirdparty/harfbuzz/NEWS
+++ b/thirdparty/harfbuzz/NEWS
@@ -1,3 +1,18 @@
+Overview of changes leading to 2.8.0
+Tuesday, March 16, 2021
+====================================
+- Shape joining scripts other than Arabic/Syriac using the Universal Shaping Engine.
+  Previously these were shaped using the generalized Arabic shaper. (David Corbett)
+- Fix regression in shaping of U+0B55 ORIYA SIGN OVERLINE. (David Corbett)
+- Update language tags. (David Corbett)
+- Variations: reduce error: do not round each interpolated delta. (Just van Rossum) 
+- Documentation improvements. (Khaled Hosny, Nathan Willis)
+- Subsetter improvements: subsets most, if not all, lookup types now. (Garret Rieger, Qunxin Liu)
+- Fuzzer-found fixes and other improvements when memory failures happen. (Behdad)
+- Removed most atomic implementations now that we have C++11 atomic impl. (Behdad)
+- General codebase upkeep; using more C++11 features: constexpr constructors, etc. (Behdad)
+
+
 Overview of changes leading to 2.7.4
 Sunday, December 27, 2020
 ====================================
diff --git a/thirdparty/harfbuzz/src/hb-aat-layout-common.hh b/thirdparty/harfbuzz/src/hb-aat-layout-common.hh
index 75d523f5fc..98ed20d8eb 100644
--- a/thirdparty/harfbuzz/src/hb-aat-layout-common.hh
+++ b/thirdparty/harfbuzz/src/hb-aat-layout-common.hh
@@ -510,7 +510,7 @@ struct StateTable
   const Entry<Extra> &get_entry (int state, unsigned int klass) const
   {
     if (unlikely (klass >= nClasses))
-      klass = StateTable<Types, Entry<Extra>>::CLASS_OUT_OF_BOUNDS;
+      klass = StateTable::CLASS_OUT_OF_BOUNDS;
 
     const HBUSHORT *states = (this+stateArrayTable).arrayZ;
     const Entry<Extra> *entries = (this+entryTable).arrayZ;
@@ -576,7 +576,7 @@ struct StateTable
 	  if (unlikely (stop > states))
 	    return_trace (false);
 	  for (const HBUSHORT *p = states; stop < p; p--)
-	    num_entries = hb_max (num_entries, *(p - 1) + 1);
+	    num_entries = hb_max (num_entries, *(p - 1) + 1u);
 	  state_neg = min_state;
 	}
       }
@@ -597,7 +597,7 @@ struct StateTable
 	  if (unlikely (stop < states))
 	    return_trace (false);
 	  for (const HBUSHORT *p = &states[state_pos * num_classes]; p < stop; p++)
-	    num_entries = hb_max (num_entries, *p + 1);
+	    num_entries = hb_max (num_entries, *p + 1u);
 	  state_pos = max_state + 1;
 	}
       }
@@ -729,7 +729,10 @@ struct ExtendedTypes
 template <typename Types, typename EntryData>
 struct StateTableDriver
 {
-  StateTableDriver (const StateTable<Types, EntryData> &machine_,
+  using StateTableT = StateTable<Types, EntryData>;
+  using EntryT = Entry<EntryData>;
+
+  StateTableDriver (const StateTableT &machine_,
 		    hb_buffer_t *buffer_,
 		    hb_face_t *face_) :
 	      machine (machine_),
@@ -742,59 +745,101 @@ struct StateTableDriver
     if (!c->in_place)
       buffer->clear_output ();
 
-    int state = StateTable<Types, EntryData>::STATE_START_OF_TEXT;
+    int state = StateTableT::STATE_START_OF_TEXT;
     for (buffer->idx = 0; buffer->successful;)
     {
       unsigned int klass = buffer->idx < buffer->len ?
 			   machine.get_class (buffer->info[buffer->idx].codepoint, num_glyphs) :
-			   (unsigned) StateTable<Types, EntryData>::CLASS_END_OF_TEXT;
+			   (unsigned) StateTableT::CLASS_END_OF_TEXT;
       DEBUG_MSG (APPLY, nullptr, "c%u at %u", klass, buffer->idx);
-      const Entry<EntryData> &entry = machine.get_entry (state, klass);
+      const EntryT &entry = machine.get_entry (state, klass);
+      const int next_state = machine.new_state (entry.newState);
 
-      /* Unsafe-to-break before this if not in state 0, as things might
-       * go differently if we start from state 0 here.
+      /* Conditions under which it's guaranteed safe-to-break before current glyph:
        *
-       * Ugh.  The indexing here is ugly... */
-      if (state && buffer->backtrack_len () && buffer->idx < buffer->len)
-      {
-	/* If there's no action and we're just epsilon-transitioning to state 0,
-	 * safe to break. */
-	if (c->is_actionable (this, entry) ||
-	    !(entry.newState == StateTable<Types, EntryData>::STATE_START_OF_TEXT &&
-	      entry.flags == context_t::DontAdvance))
-	  buffer->unsafe_to_break_from_outbuffer (buffer->backtrack_len () - 1, buffer->idx + 1);
-      }
-
-      /* Unsafe-to-break if end-of-text would kick in here. */
-      if (buffer->idx + 2 <= buffer->len)
-      {
-	const Entry<EntryData> &end_entry = machine.get_entry (state, StateTable<Types, EntryData>::CLASS_END_OF_TEXT);
-	if (c->is_actionable (this, end_entry))
-	  buffer->unsafe_to_break (buffer->idx, buffer->idx + 2);
-      }
+       * 1. There was no action in this transition; and
+       *
+       * 2. If we break before current glyph, the results will be the same. That
+       *    is guaranteed if:
+       *
+       *    2a. We were already in start-of-text state; or
+       *
+       *    2b. We are epsilon-transitioning to start-of-text state; or
+       *
+       *    2c. Starting from start-of-text state seeing current glyph:
+       *
+       *        2c'. There won't be any actions; and
+       *
+       *        2c". We would end up in the same state that we were going to end up
+       *             in now, including whether epsilon-transitioning.
+       *
+       *    and
+       *
+       * 3. If we break before current glyph, there won't be any end-of-text action
+       *    after previous glyph.
+       *
+       * This triples the transitions we need to look up, but is worth returning
+       * granular unsafe-to-break results. See eg.:
+       *
+       *   https://github.com/harfbuzz/harfbuzz/issues/2860
+       */
+      const EntryT *wouldbe_entry;
+      bool safe_to_break =
+	/* 1. */
+	!c->is_actionable (this, entry)
+      &&
+	/* 2. */
+	(
+	  /* 2a. */
+	  state == StateTableT::STATE_START_OF_TEXT
+	||
+	  /* 2b. */
+	  (
+	    (entry.flags & context_t::DontAdvance) &&
+	    next_state == StateTableT::STATE_START_OF_TEXT
+	  )
+	||
+	  /* 2c. */
+	  (
+	    wouldbe_entry = &machine.get_entry (StateTableT::STATE_START_OF_TEXT, klass)
+	  ,
+	    /* 2c'. */
+	    !c->is_actionable (this, *wouldbe_entry)
+	  &&
+	    /* 2c". */
+	    (
+	      next_state == machine.new_state (wouldbe_entry->newState)
+	    &&
+	      (entry.flags & context_t::DontAdvance) == (wouldbe_entry->flags & context_t::DontAdvance)
+	    )
+	  )
+	)
+      &&
+	/* 3. */
+	!c->is_actionable (this, machine.get_entry (state, StateTableT::CLASS_END_OF_TEXT))
+      ;
+
+      if (!safe_to_break && buffer->backtrack_len () && buffer->idx < buffer->len)
+	buffer->unsafe_to_break_from_outbuffer (buffer->backtrack_len () - 1, buffer->idx + 1);
 
       c->transition (this, entry);
 
-      state = machine.new_state (entry.newState);
+      state = next_state;
       DEBUG_MSG (APPLY, nullptr, "s%d", state);
 
-      if (buffer->idx == buffer->len)
+      if (buffer->idx == buffer->len || unlikely (!buffer->successful))
 	break;
 
       if (!(entry.flags & context_t::DontAdvance) || buffer->max_ops-- <= 0)
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
     }
 
     if (!c->in_place)
-    {
-      for (; buffer->successful && buffer->idx < buffer->len;)
-	buffer->next_glyph ();
       buffer->swap_buffers ();
-    }
   }
 
   public:
-  const StateTable<Types, EntryData> &machine;
+  const StateTableT &machine;
   hb_buffer_t *buffer;
   unsigned int num_glyphs;
 };
diff --git a/thirdparty/harfbuzz/src/hb-aat-layout-morx-table.hh b/thirdparty/harfbuzz/src/hb-aat-layout-morx-table.hh
index 04027a61be..e3bc268d26 100644
--- a/thirdparty/harfbuzz/src/hb-aat-layout-morx-table.hh
+++ b/thirdparty/harfbuzz/src/hb-aat-layout-morx-table.hh
@@ -337,9 +337,9 @@ struct ContextualSubtable
       const EntryData &data = entries[i].data;
 
       if (data.markIndex != 0xFFFF)
-	num_lookups = hb_max (num_lookups, 1 + data.markIndex);
+	num_lookups = hb_max (num_lookups, 1u + data.markIndex);
       if (data.currentIndex != 0xFFFF)
-	num_lookups = hb_max (num_lookups, 1 + data.currentIndex);
+	num_lookups = hb_max (num_lookups, 1u + data.currentIndex);
     }
 
     return_trace (substitutionTables.sanitize (c, this, num_lookups));
@@ -499,7 +499,7 @@ struct LigatureSubtable
 	  }
 
 	  DEBUG_MSG (APPLY, nullptr, "Moving to stack position %u", cursor - 1);
-	  buffer->move_to (match_positions[--cursor % ARRAY_LENGTH (match_positions)]);
+	  if (unlikely (!buffer->move_to (match_positions[--cursor % ARRAY_LENGTH (match_positions)]))) return;
 
 	  if (unlikely (!actionData->sanitize (&c->sanitizer))) break;
 	  action = *actionData;
@@ -525,25 +525,25 @@ struct LigatureSubtable
 	    hb_codepoint_t lig = ligatureData;
 
 	    DEBUG_MSG (APPLY, nullptr, "Produced ligature %u", lig);
-	    buffer->replace_glyph (lig);
+	    if (unlikely (!buffer->replace_glyph (lig))) return;
 
 	    unsigned int lig_end = match_positions[(match_length - 1u) % ARRAY_LENGTH (match_positions)] + 1u;
 	    /* Now go and delete all subsequent components. */
 	    while (match_length - 1u > cursor)
 	    {
 	      DEBUG_MSG (APPLY, nullptr, "Skipping ligature component");
-	      buffer->move_to (match_positions[--match_length % ARRAY_LENGTH (match_positions)]);
-	      buffer->replace_glyph (DELETED_GLYPH);
+	      if (unlikely (!buffer->move_to (match_positions[--match_length % ARRAY_LENGTH (match_positions)]))) return;
+	      if (unlikely (!buffer->replace_glyph (DELETED_GLYPH))) return;
 	    }
 
-	    buffer->move_to (lig_end);
+	    if (unlikely (!buffer->move_to (lig_end))) return;
 	    buffer->merge_out_clusters (match_positions[cursor % ARRAY_LENGTH (match_positions)], buffer->out_len);
 	  }
 
 	  actionData++;
 	}
 	while (!(action & LigActionLast));
-	buffer->move_to (end);
+	if (unlikely (!buffer->move_to (end))) return;
       }
     }
 
@@ -733,17 +733,16 @@ struct InsertionSubtable
 	bool before = flags & MarkedInsertBefore;
 
 	unsigned int end = buffer->out_len;
-	buffer->move_to (mark);
+	if (unlikely (!buffer->move_to (mark))) return;
 
 	if (buffer->idx < buffer->len && !before)
-	  buffer->copy_glyph ();
+	  if (unlikely (!buffer->copy_glyph ())) return;
 	/* TODO We ignore KashidaLike setting. */
-	for (unsigned int i = 0; i < count; i++)
-	  buffer->output_glyph (glyphs[i]);
+	if (unlikely (!buffer->replace_glyphs (0, count, glyphs))) return;
 	if (buffer->idx < buffer->len && !before)
 	  buffer->skip_glyph ();
 
-	buffer->move_to (end + count);
+	if (unlikely (!buffer->move_to (end + count))) return;
 
 	buffer->unsafe_to_break_from_outbuffer (mark, hb_min (buffer->idx + 1, buffer->len));
       }
@@ -764,10 +763,9 @@ struct InsertionSubtable
 	unsigned int end = buffer->out_len;
 
 	if (buffer->idx < buffer->len && !before)
-	  buffer->copy_glyph ();
+	  if (unlikely (!buffer->copy_glyph ())) return;
 	/* TODO We ignore KashidaLike setting. */
-	for (unsigned int i = 0; i < count; i++)
-	  buffer->output_glyph (glyphs[i]);
+	if (unlikely (!buffer->replace_glyphs (0, count, glyphs))) return;
 	if (buffer->idx < buffer->len && !before)
 	  buffer->skip_glyph ();
 
@@ -786,7 +784,7 @@ struct InsertionSubtable
 	 *
 	 * https://github.com/harfbuzz/harfbuzz/issues/1224#issuecomment-427691417
 	 */
-	buffer->move_to ((flags & DontAdvance) ? end : end + count);
+	if (unlikely (!buffer->move_to ((flags & DontAdvance) ? end : end + count))) return;
       }
     }
 
diff --git a/thirdparty/harfbuzz/src/hb-aat-layout.cc b/thirdparty/harfbuzz/src/hb-aat-layout.cc
index 74ebaa64ec..0e9f2b4954 100644
--- a/thirdparty/harfbuzz/src/hb-aat-layout.cc
+++ b/thirdparty/harfbuzz/src/hb-aat-layout.cc
@@ -227,7 +227,7 @@ hb_aat_layout_compile_map (const hb_aat_map_builder_t *mapper,
  *
  * <note>Note: does not examine the `GSUB` table.</note>
  *
- * Return value: true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 2.3.0
  */
@@ -294,7 +294,7 @@ hb_aat_layout_remove_deleted_glyphs (hb_buffer_t *buffer)
  *
  * <note>Note: does not examine the `GPOS` table.</note>
  *
- * Return value: true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 2.3.0
  */
@@ -325,7 +325,7 @@ hb_aat_layout_position (const hb_ot_shape_plan_t *plan,
  * Tests whether the specified face includes any tracking information
  * in the `trak` table.
  *
- * Return value: true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 2.3.0
  */
@@ -350,7 +350,7 @@ hb_aat_layout_track (const hb_ot_shape_plan_t *plan,
  * hb_aat_layout_get_feature_types:
  * @face: #hb_face_t to work upon
  * @start_offset: offset of the first feature type to retrieve
- * @feature_count: (inout) (allow-none): Input = the maximum number of feature types to return;
+ * @feature_count: (inout) (optional): Input = the maximum number of feature types to return;
  *                 Output = the actual number of feature types returned (may be zero)
  * @features: (out caller-allocates) (array length=feature_count): Array of feature types found
  *
@@ -374,9 +374,9 @@ hb_aat_layout_get_feature_types (hb_face_t                    *face,
  * @face: #hb_face_t to work upon
  * @feature_type: The #hb_aat_layout_feature_type_t of the requested feature type
  *
- * Fetches the name ID of the specified feature type in the face's `name` table.
+ * Fetches the name identifier of the specified feature type in the face's `name` table.
  *
- * Return value: Name ID of the requested feature type
+ * Return value: Name identifier of the requested feature type
  *
  * Since: 2.2.0
  */
@@ -388,15 +388,15 @@ hb_aat_layout_feature_type_get_name_id (hb_face_t                    *face,
 }
 
 /**
- * hb_aat_layout_feature_type_get_selectors:
+ * hb_aat_layout_feature_type_get_selector_infos:
  * @face: #hb_face_t to work upon
  * @feature_type: The #hb_aat_layout_feature_type_t of the requested feature type
  * @start_offset: offset of the first feature type to retrieve
- * @selector_count: (inout) (allow-none): Input = the maximum number of selectors to return;
+ * @selector_count: (inout) (optional): Input = the maximum number of selectors to return;
  *                  Output = the actual number of selectors returned (may be zero)
- * @selectors: (out caller-allocates) (array length=selector_count): A buffer pointer.
- *             The selectors available for the feature type queries.
- * @default_index: (out) (allow-none): The index of the feature's default selector, if any
+ * @selectors: (out caller-allocates) (array length=selector_count) (optional):
+ *             A buffer pointer. The selectors available for the feature type queries.
+ * @default_index: (out) (optional): The index of the feature's default selector, if any
  *
  * Fetches a list of the selectors available for the specified feature in the given face.
  *
diff --git a/thirdparty/harfbuzz/src/hb-aat-layout.h b/thirdparty/harfbuzz/src/hb-aat-layout.h
index dc1bf96573..9af2740088 100644
--- a/thirdparty/harfbuzz/src/hb-aat-layout.h
+++ b/thirdparty/harfbuzz/src/hb-aat-layout.h
@@ -22,7 +22,7 @@
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  */
 
-#ifndef HB_AAT_H_IN
+#if !defined(HB_AAT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-aat.h> instead."
 #endif
 
@@ -38,47 +38,47 @@ HB_BEGIN_DECLS
 /**
  * hb_aat_layout_feature_type_t:
  * @HB_AAT_LAYOUT_FEATURE_TYPE_INVALID: Initial, unset feature type
- * @HB_AAT_LAYOUT_FEATURE_TYPE_ALL_TYPOGRAPHIC:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_LIGATURES:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_CURISVE_CONNECTION:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_LETTER_CASE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_VERTICAL_SUBSTITUTION:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_LINGUISTIC_REARRANGEMENT:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_NUMBER_SPACING:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_SMART_SWASH_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_DIACRITICS_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_VERTICAL_POSITION:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_FRACTIONS:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_OVERLAPPING_CHARACTERS_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_TYPOGRAPHIC_EXTRAS:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_MATHEMATICAL_EXTRAS:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_ORNAMENT_SETS_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_CHARACTER_ALTERNATIVES:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_DESIGN_COMPLEXITY_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_STYLE_OPTIONS:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_CHARACTER_SHAPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_NUMBER_CASE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_TEXT_SPACING:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_TRANSLITERATION:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_ANNOTATION_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_KANA_SPACING_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_IDEOGRAPHIC_SPACING_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_UNICODE_DECOMPOSITION_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_RUBY_KANA:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_CJK_SYMBOL_ALTERNATIVES_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_IDEOGRAPHIC_ALTERNATIVES_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_CJK_VERTICAL_ROMAN_PLACEMENT_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_ITALIC_CJK_ROMAN:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_CASE_SENSITIVE_LAYOUT:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_ALTERNATE_KANA:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_STYLISTIC_ALTERNATIVES:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_CONTEXTUAL_ALTERNATIVES:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_LOWER_CASE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_UPPER_CASE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_LANGUAGE_TAG_TYPE:
- * @HB_AAT_LAYOUT_FEATURE_TYPE_CJK_ROMAN_SPACING_TYPE:
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_ALL_TYPOGRAPHIC: [All Typographic Features](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type0)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_LIGATURES: [Ligatures](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type1)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_CURISVE_CONNECTION: [Cursive Connection](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type2)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_LETTER_CASE: [Letter Case](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type3)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_VERTICAL_SUBSTITUTION: [Vertical Substitution](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type4)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_LINGUISTIC_REARRANGEMENT: [Linguistic Rearrangement](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type5)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_NUMBER_SPACING: [Number Spacing](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type6)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_SMART_SWASH_TYPE: [Smart Swash](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type8)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_DIACRITICS_TYPE: [Diacritics](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type9)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_VERTICAL_POSITION: [Vertical Position](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type10)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_FRACTIONS: [Fractions](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type11)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_OVERLAPPING_CHARACTERS_TYPE: [Overlapping Characters](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type13)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_TYPOGRAPHIC_EXTRAS: [Typographic Extras](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type14)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_MATHEMATICAL_EXTRAS: [Mathematical Extras](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type15)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_ORNAMENT_SETS_TYPE: [Ornament Sets](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type16)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_CHARACTER_ALTERNATIVES: [Character Alternatives](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type17)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_DESIGN_COMPLEXITY_TYPE: [Design Complexity](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type18)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_STYLE_OPTIONS: [Style Options](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type19)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_CHARACTER_SHAPE: [Character Shape](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type20)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_NUMBER_CASE: [Number Case](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type21)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_TEXT_SPACING: [Text Spacing](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type22)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_TRANSLITERATION: [Transliteration](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type23)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_ANNOTATION_TYPE: [Annotation](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type24)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_KANA_SPACING_TYPE: [Kana Spacing](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type25)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_IDEOGRAPHIC_SPACING_TYPE: [Ideographic Spacing](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type26)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_UNICODE_DECOMPOSITION_TYPE: [Unicode Decomposition](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type27)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_RUBY_KANA: [Ruby Kana](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type28)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_CJK_SYMBOL_ALTERNATIVES_TYPE: [CJK Symbol Alternatives](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type29)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_IDEOGRAPHIC_ALTERNATIVES_TYPE: [Ideographic Alternatives](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type30)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_CJK_VERTICAL_ROMAN_PLACEMENT_TYPE: [CJK Vertical Roman Placement](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type31)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_ITALIC_CJK_ROMAN: [Italic CJK Roman](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type32)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_CASE_SENSITIVE_LAYOUT: [Case Sensitive Layout](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type33)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_ALTERNATE_KANA: [Alternate Kana](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type34)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_STYLISTIC_ALTERNATIVES: [Stylistic Alternatives](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type35)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_CONTEXTUAL_ALTERNATIVES: [Contextual Alternatives](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type36)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_LOWER_CASE: [Lower Case](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type37)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_UPPER_CASE: [Upper Case](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type38)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_LANGUAGE_TAG_TYPE: [Language Tag](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type39)
+ * @HB_AAT_LAYOUT_FEATURE_TYPE_CJK_ROMAN_SPACING_TYPE: [CJK Roman Spacing](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html#Type103)
  *
- * The possible feature types defined for AAT shaping.
+ * The possible feature types defined for AAT shaping, from Apple [Font Feature Registry](https://developer.apple.com/fonts/TrueType-Reference-Manual/RM09/AppendixF.html).
  *
  * Since: 2.2.0
  */
@@ -732,6 +732,14 @@ HB_EXTERN hb_ot_name_id_t
 hb_aat_layout_feature_type_get_name_id (hb_face_t                    *face,
 					hb_aat_layout_feature_type_t  feature_type);
 
+/**
+ * hb_aat_layout_feature_selector_info_t:
+ * @name_id: The selector's name identifier
+ * @enable: The value to turn the selector on
+ * @disable: The value to turn the selector off
+ *
+ * Structure representing a setting for an #hb_aat_layout_feature_type_t.
+ */
 typedef struct hb_aat_layout_feature_selector_info_t {
   hb_ot_name_id_t			name_id;
   hb_aat_layout_feature_selector_t	enable;
diff --git a/thirdparty/harfbuzz/src/hb-algs.hh b/thirdparty/harfbuzz/src/hb-algs.hh
index 98de61f3e8..bc170b0546 100644
--- a/thirdparty/harfbuzz/src/hb-algs.hh
+++ b/thirdparty/harfbuzz/src/hb-algs.hh
@@ -35,6 +35,132 @@
 #include "hb-number.hh"
 
 
+/*
+ * Flags
+ */
+
+/* Enable bitwise ops on enums marked as flags_t */
+/* To my surprise, looks like the function resolver is happy to silently cast
+ * one enum to another...  So this doesn't provide the type-checking that I
+ * originally had in mind... :(.
+ *
+ * For MSVC warnings, see: https://github.com/harfbuzz/harfbuzz/pull/163
+ */
+#ifdef _MSC_VER
+# pragma warning(disable:4200)
+# pragma warning(disable:4800)
+#endif
+#define HB_MARK_AS_FLAG_T(T) \
+	extern "C++" { \
+	  static inline constexpr T operator | (T l, T r) { return T ((unsigned) l | (unsigned) r); } \
+	  static inline constexpr T operator & (T l, T r) { return T ((unsigned) l & (unsigned) r); } \
+	  static inline constexpr T operator ^ (T l, T r) { return T ((unsigned) l ^ (unsigned) r); } \
+	  static inline constexpr T operator ~ (T r) { return T (~(unsigned int) r); } \
+	  static inline T& operator |= (T &l, T r) { l = l | r; return l; } \
+	  static inline T& operator &= (T& l, T r) { l = l & r; return l; } \
+	  static inline T& operator ^= (T& l, T r) { l = l ^ r; return l; } \
+	} \
+	static_assert (true, "")
+
+/* Useful for set-operations on small enums.
+ * For example, for testing "x ∈ {x1, x2, x3}" use:
+ * (FLAG_UNSAFE(x) & (FLAG(x1) | FLAG(x2) | FLAG(x3)))
+ */
+#define FLAG(x) (static_assert_expr ((unsigned)(x) < 32) + (((uint32_t) 1U) << (unsigned)(x)))
+#define FLAG_UNSAFE(x) ((unsigned)(x) < 32 ? (((uint32_t) 1U) << (unsigned)(x)) : 0)
+#define FLAG_RANGE(x,y) (static_assert_expr ((x) < (y)) + FLAG(y+1) - FLAG(x))
+#define FLAG64(x) (static_assert_expr ((unsigned)(x) < 64) + (((uint64_t) 1ULL) << (unsigned)(x)))
+#define FLAG64_UNSAFE(x) ((unsigned)(x) < 64 ? (((uint64_t) 1ULL) << (unsigned)(x)) : 0)
+
+
+/*
+ * Big-endian integers.
+ */
+
+/* Endian swap, used in Windows related backends */
+static inline constexpr uint16_t hb_uint16_swap (uint16_t v)
+{ return (v >> 8) | (v << 8); }
+static inline constexpr uint32_t hb_uint32_swap (uint32_t v)
+{ return (hb_uint16_swap (v) << 16) | hb_uint16_swap (v >> 16); }
+
+template <typename Type, int Bytes = sizeof (Type)>
+struct BEInt;
+template <typename Type>
+struct BEInt<Type, 1>
+{
+  public:
+  BEInt () = default;
+  constexpr BEInt (Type V) : v {uint8_t (V)} {}
+  constexpr operator Type () const { return v; }
+  private: uint8_t v;
+};
+template <typename Type>
+struct BEInt<Type, 2>
+{
+  public:
+  BEInt () = default;
+  constexpr BEInt (Type V) : v {uint8_t ((V >>  8) & 0xFF),
+			        uint8_t ((V      ) & 0xFF)} {}
+
+  struct __attribute__((packed)) packed_uint16_t { uint16_t v; };
+  constexpr operator Type () const
+  {
+#if ((defined(__GNUC__) && __GNUC__ >= 5) || defined(__clang__)) && \
+    defined(__BYTE_ORDER) && \
+    (__BYTE_ORDER == __LITTLE_ENDIAN || __BYTE_ORDER == __BIG_ENDIAN)
+    /* Spoon-feed the compiler a big-endian integer with alignment 1.
+     * https://github.com/harfbuzz/harfbuzz/pull/1398 */
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+    return __builtin_bswap16 (((packed_uint16_t *) this)->v);
+#else /* __BYTE_ORDER == __BIG_ENDIAN */
+    return ((packed_uint16_t *) this)->v;
+#endif
+#else
+    return (v[0] <<  8)
+	 + (v[1]      );
+#endif
+  }
+  private: uint8_t v[2];
+};
+template <typename Type>
+struct BEInt<Type, 3>
+{
+  static_assert (!hb_is_signed (Type), "");
+  public:
+  BEInt () = default;
+  constexpr BEInt (Type V) : v {uint8_t ((V >> 16) & 0xFF),
+				uint8_t ((V >>  8) & 0xFF),
+				uint8_t ((V      ) & 0xFF)} {}
+
+  constexpr operator Type () const { return (v[0] << 16)
+					  + (v[1] <<  8)
+					  + (v[2]      ); }
+  private: uint8_t v[3];
+};
+template <typename Type>
+struct BEInt<Type, 4>
+{
+  public:
+  BEInt () = default;
+  constexpr BEInt (Type V) : v {uint8_t ((V >> 24) & 0xFF),
+			        uint8_t ((V >> 16) & 0xFF),
+			        uint8_t ((V >>  8) & 0xFF),
+			        uint8_t ((V      ) & 0xFF)} {}
+  constexpr operator Type () const { return (v[0] << 24)
+					  + (v[1] << 16)
+					  + (v[2] <<  8)
+					  + (v[3]      ); }
+  private: uint8_t v[4];
+};
+
+/* Floats. */
+
+/* We want our rounding towards +infinity. */
+static inline float
+_hb_roundf (float x) { return floorf (x + .5f); }
+#define roundf(x) _hb_roundf(x)
+
+
 /* Encodes three unsigned integers in one 64-bit number.  If the inputs have more than 21 bits,
  * values will be truncated / overlap, and might not decode exactly. */
 #define HB_CODEPOINT_ENCODE3(x,y,z) (((uint64_t) (x) << 42) | ((uint64_t) (y) << 21) | (uint64_t) (z))
@@ -48,6 +174,7 @@
 #define HB_CODEPOINT_DECODE3_11_7_14_2(v) ((hb_codepoint_t) (((v) >> 14) & 0x007Fu) | 0x0300)
 #define HB_CODEPOINT_DECODE3_11_7_14_3(v) ((hb_codepoint_t) (v) & 0x3FFFu)
 
+
 struct
 {
   /* Note.  This is dangerous in that if it's passed an rvalue, it returns rvalue-reference. */
@@ -215,7 +342,9 @@ struct
 
   template <typename Pred, typename Val> auto
   impl (Pred&& p, Val &&v, hb_priority<1>) const HB_AUTO_RETURN
-  (hb_deref (hb_forward<Pred> (p)).has (hb_forward<Val> (v)))
+  (
+    hb_deref (hb_forward<Pred> (p)).has (hb_forward<Val> (v))
+  )
 
   template <typename Pred, typename Val> auto
   impl (Pred&& p, Val &&v, hb_priority<0>) const HB_AUTO_RETURN
@@ -269,7 +398,9 @@ struct
 
   template <typename Proj, typename Val> auto
   impl (Proj&& f, Val &&v, hb_priority<2>) const HB_AUTO_RETURN
-  (hb_deref (hb_forward<Proj> (f)).get (hb_forward<Val> (v)))
+  (
+    hb_deref (hb_forward<Proj> (f)).get (hb_forward<Val> (v))
+  )
 
   template <typename Proj, typename Val> auto
   impl (Proj&& f, Val &&v, hb_priority<1>) const HB_AUTO_RETURN
@@ -296,6 +427,40 @@ struct
 }
 HB_FUNCOBJ (hb_get);
 
+struct
+{
+  private:
+
+  template <typename T1, typename T2> auto
+  impl (T1&& v1, T2 &&v2, hb_priority<2>) const HB_AUTO_RETURN
+  (
+    hb_forward<T2> (v2).cmp (hb_forward<T1> (v1)) == 0
+  )
+
+  template <typename T1, typename T2> auto
+  impl (T1&& v1, T2 &&v2, hb_priority<1>) const HB_AUTO_RETURN
+  (
+    hb_forward<T1> (v1).cmp (hb_forward<T2> (v2)) == 0
+  )
+
+  template <typename T1, typename T2> auto
+  impl (T1&& v1, T2 &&v2, hb_priority<0>) const HB_AUTO_RETURN
+  (
+    hb_forward<T1> (v1) == hb_forward<T2> (v2)
+  )
+
+  public:
+
+  template <typename T1, typename T2> auto
+  operator () (T1&& v1, T2 &&v2) const HB_AUTO_RETURN
+  (
+    impl (hb_forward<T1> (v1),
+	  hb_forward<T2> (v2),
+	  hb_prioritize)
+  )
+}
+HB_FUNCOBJ (hb_equal);
+
 
 template <typename T1, typename T2>
 struct hb_pair_t
@@ -375,7 +540,7 @@ HB_FUNCOBJ (hb_clamp);
 
 /* Return the number of 1 bits in v. */
 template <typename T>
-static inline HB_CONST_FUNC unsigned int
+static inline unsigned int
 hb_popcount (T v)
 {
 #if (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__)
@@ -416,7 +581,7 @@ hb_popcount (T v)
 
 /* Returns the number of bits needed to store number */
 template <typename T>
-static inline HB_CONST_FUNC unsigned int
+static inline unsigned int
 hb_bit_storage (T v)
 {
   if (unlikely (!v)) return 0;
@@ -490,7 +655,7 @@ hb_bit_storage (T v)
 
 /* Returns the number of zero bits in the least significant side of v */
 template <typename T>
-static inline HB_CONST_FUNC unsigned int
+static inline unsigned int
 hb_ctz (T v)
 {
   if (unlikely (!v)) return 8 * sizeof (T);
@@ -988,32 +1153,24 @@ hb_codepoint_parse (const char *s, unsigned int len, int base, hb_codepoint_t *o
 
 struct hb_bitwise_and
 { HB_PARTIALIZE(2);
-  static constexpr bool passthru_left = false;
-  static constexpr bool passthru_right = false;
   template <typename T> constexpr auto
   operator () (const T &a, const T &b) const HB_AUTO_RETURN (a & b)
 }
 HB_FUNCOBJ (hb_bitwise_and);
 struct hb_bitwise_or
 { HB_PARTIALIZE(2);
-  static constexpr bool passthru_left = true;
-  static constexpr bool passthru_right = true;
   template <typename T> constexpr auto
   operator () (const T &a, const T &b) const HB_AUTO_RETURN (a | b)
 }
 HB_FUNCOBJ (hb_bitwise_or);
 struct hb_bitwise_xor
 { HB_PARTIALIZE(2);
-  static constexpr bool passthru_left = true;
-  static constexpr bool passthru_right = true;
   template <typename T> constexpr auto
   operator () (const T &a, const T &b) const HB_AUTO_RETURN (a ^ b)
 }
 HB_FUNCOBJ (hb_bitwise_xor);
 struct hb_bitwise_sub
 { HB_PARTIALIZE(2);
-  static constexpr bool passthru_left = true;
-  static constexpr bool passthru_right = false;
   template <typename T> constexpr auto
   operator () (const T &a, const T &b) const HB_AUTO_RETURN (a & ~b)
 }
diff --git a/thirdparty/harfbuzz/src/hb-array.hh b/thirdparty/harfbuzz/src/hb-array.hh
index 568cd02c79..02bd8d81c2 100644
--- a/thirdparty/harfbuzz/src/hb-array.hh
+++ b/thirdparty/harfbuzz/src/hb-array.hh
@@ -142,7 +142,7 @@ struct hb_array_t : hb_iter_with_fallback_t<hb_array_t<Type>, Type&>
   bool lfind (const T &x, unsigned *pos = nullptr) const
   {
     for (unsigned i = 0; i < length; ++i)
-      if (!this->arrayZ[i].cmp (x))
+      if (hb_equal (x, this->arrayZ[i]))
       {
 	if (pos)
 	  *pos = i;
diff --git a/thirdparty/harfbuzz/src/hb-atomic.hh b/thirdparty/harfbuzz/src/hb-atomic.hh
index b3fb296b4e..93265f655f 100644
--- a/thirdparty/harfbuzz/src/hb-atomic.hh
+++ b/thirdparty/harfbuzz/src/hb-atomic.hh
@@ -52,7 +52,7 @@
 
 #elif !defined(HB_NO_MT) && defined(__ATOMIC_ACQUIRE)
 
-/* C++11-style GCC primitives. */
+/* C++11-style GCC primitives. We prefer these as they don't require linking to libstdc++ / libc++. */
 
 #define _hb_memory_barrier()			__sync_synchronize ()
 
@@ -73,7 +73,8 @@ _hb_atomic_ptr_impl_cmplexch (const void **P, const void *O_, const void *N)
 }
 #define hb_atomic_ptr_impl_cmpexch(P,O,N)	_hb_atomic_ptr_impl_cmplexch ((const void **) (P), (O), (N))
 
-#elif !defined(HB_NO_MT) && __cplusplus >= 201103L
+
+#elif !defined(HB_NO_MT)
 
 /* C++11 atomics. */
 
@@ -101,117 +102,6 @@ _hb_atomic_ptr_impl_cmplexch (const void **P, const void *O_, const void *N)
 #define hb_atomic_ptr_impl_cmpexch(P,O,N)	_hb_atomic_ptr_impl_cmplexch ((const void **) (P), (O), (N))
 
 
-#elif !defined(HB_NO_MT) && defined(_WIN32)
-
-#include <windows.h>
-
-static inline void _hb_memory_barrier ()
-{
-#if !defined(MemoryBarrier) && !defined(__MINGW32_VERSION)
-  /* MinGW has a convoluted history of supporting MemoryBarrier. */
-  LONG dummy = 0;
-  InterlockedExchange (&dummy, 1);
-#else
-  MemoryBarrier ();
-#endif
-}
-#define _hb_memory_barrier()			_hb_memory_barrier ()
-
-#define hb_atomic_int_impl_add(AI, V)		InterlockedExchangeAdd ((LONG *) (AI), (V))
-static_assert ((sizeof (LONG) == sizeof (int)), "");
-
-#define hb_atomic_ptr_impl_cmpexch(P,O,N)	(InterlockedCompareExchangePointer ((P), (N), (O)) == (O))
-
-
-#elif !defined(HB_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
-
-#define _hb_memory_barrier()			__sync_synchronize ()
-
-#define hb_atomic_int_impl_add(AI, V)		__sync_fetch_and_add ((AI), (V))
-
-#define hb_atomic_ptr_impl_cmpexch(P,O,N)	__sync_bool_compare_and_swap ((P), (O), (N))
-
-
-#elif !defined(HB_NO_MT) && defined(HAVE_SOLARIS_ATOMIC_OPS)
-
-#include <atomic.h>
-#include <mbarrier.h>
-
-#define _hb_memory_r_barrier()			__machine_r_barrier ()
-#define _hb_memory_w_barrier()			__machine_w_barrier ()
-#define _hb_memory_barrier()			__machine_rw_barrier ()
-
-static inline int _hb_fetch_and_add (int *AI, int V)
-{
-  _hb_memory_w_barrier ();
-  int result = atomic_add_int_nv ((uint_t *) AI, V) - V;
-  _hb_memory_r_barrier ();
-  return result;
-}
-static inline bool _hb_compare_and_swap_ptr (void **P, void *O, void *N)
-{
-  _hb_memory_w_barrier ();
-  bool result = atomic_cas_ptr (P, O, N) == O;
-  _hb_memory_r_barrier ();
-  return result;
-}
-
-#define hb_atomic_int_impl_add(AI, V)           _hb_fetch_and_add ((AI), (V))
-
-#define hb_atomic_ptr_impl_cmpexch(P,O,N)       _hb_compare_and_swap_ptr ((P), (O), (N))
-
-
-#elif !defined(HB_NO_MT) && defined(__APPLE__)
-
-#include <libkern/OSAtomic.h>
-#ifdef __MAC_OS_X_MIN_REQUIRED
-#include <AvailabilityMacros.h>
-#elif defined(__IPHONE_OS_MIN_REQUIRED)
-#include <Availability.h>
-#endif
-
-#define _hb_memory_barrier()			OSMemoryBarrier ()
-
-#define hb_atomic_int_impl_add(AI, V)		(OSAtomicAdd32Barrier ((V), (AI)) - (V))
-
-#if (MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4 || __IPHONE_VERSION_MIN_REQUIRED >= 20100)
-#define hb_atomic_ptr_impl_cmpexch(P,O,N)	OSAtomicCompareAndSwapPtrBarrier ((O), (N), (P))
-#else
-#if __ppc64__ || __x86_64__ || __aarch64__
-#define hb_atomic_ptr_impl_cmpexch(P,O,N)	OSAtomicCompareAndSwap64Barrier ((int64_t) (O), (int64_t) (N), (int64_t*) (P))
-#else
-#define hb_atomic_ptr_impl_cmpexch(P,O,N)	OSAtomicCompareAndSwap32Barrier ((int32_t) (O), (int32_t) (N), (int32_t*) (P))
-#endif
-#endif
-
-
-#elif !defined(HB_NO_MT) && defined(_AIX) && (defined(__IBMCPP__) || defined(__ibmxl__))
-
-#include <builtins.h>
-
-#define _hb_memory_barrier()			__lwsync ()
-
-static inline int _hb_fetch_and_add (int *AI, int V)
-{
-  _hb_memory_barrier ();
-  int result = __fetch_and_add (AI, V);
-  _hb_memory_barrier ();
-  return result;
-}
-static inline bool _hb_compare_and_swaplp (long *P, long O, long N)
-{
-  _hb_memory_barrier ();
-  bool result = __compare_and_swaplp (P, &O, N);
-  _hb_memory_barrier ();
-  return result;
-}
-
-#define hb_atomic_int_impl_add(AI, V)           _hb_fetch_and_add ((AI), (V))
-
-#define hb_atomic_ptr_impl_cmpexch(P,O,N)       _hb_compare_and_swaplp ((long *) (P), (long) (O), (long) (N))
-static_assert ((sizeof (long) == sizeof (void *)), "");
-
-
 #elif defined(HB_NO_MT)
 
 #define hb_atomic_int_impl_add(AI, V)		((*(AI) += (V)) - (V))
@@ -259,9 +149,11 @@ inline void *hb_atomic_ptr_impl_get (void ** const P)	{ void *v = *P; _hb_memory
 #endif
 
 
-#define HB_ATOMIC_INT_INIT(V)          {V}
 struct hb_atomic_int_t
 {
+  hb_atomic_int_t () = default;
+  constexpr hb_atomic_int_t (int v) : v (v) {}
+
   void set_relaxed (int v_) { hb_atomic_int_impl_set_relaxed (&v, v_); }
   void set (int v_) { hb_atomic_int_impl_set (&v, v_); }
   int get_relaxed () const { return hb_atomic_int_impl_get_relaxed (&v); }
@@ -269,16 +161,17 @@ struct hb_atomic_int_t
   int inc () { return hb_atomic_int_impl_add (&v,  1); }
   int dec () { return hb_atomic_int_impl_add (&v, -1); }
 
-  int v;
+  int v = 0;
 };
 
-
-#define HB_ATOMIC_PTR_INIT(V)          {V}
 template <typename P>
 struct hb_atomic_ptr_t
 {
   typedef hb_remove_pointer<P> T;
 
+  hb_atomic_ptr_t () = default;
+  constexpr hb_atomic_ptr_t (T* v) : v (v) {}
+
   void init (T* v_ = nullptr) { set_relaxed (v_); }
   void set_relaxed (T* v_) { hb_atomic_ptr_impl_set_relaxed (&v, v_); }
   T *get_relaxed () const { return (T *) hb_atomic_ptr_impl_get_relaxed (&v); }
@@ -288,7 +181,7 @@ struct hb_atomic_ptr_t
   T * operator -> () const                    { return get (); }
   template <typename C> operator C * () const { return get (); }
 
-  T *v;
+  T *v = nullptr;
 };
 
 
diff --git a/thirdparty/harfbuzz/src/hb-blob.cc b/thirdparty/harfbuzz/src/hb-blob.cc
index e340bc346d..71b1b1fc4f 100644
--- a/thirdparty/harfbuzz/src/hb-blob.cc
+++ b/thirdparty/harfbuzz/src/hb-blob.cc
@@ -35,9 +35,6 @@
 #include <sys/mman.h>
 #endif /* HAVE_SYS_MMAN_H */
 
-#include <stdio.h>
-#include <stdlib.h>
-
 
 /**
  * SECTION: hb-blob
@@ -58,7 +55,7 @@
  * @length: Length of @data in bytes.
  * @mode: Memory mode for @data.
  * @user_data: Data parameter to pass to @destroy.
- * @destroy: (optional): Callback to call when @data is not needed anymore.
+ * @destroy: (nullable): Callback to call when @data is not needed anymore.
  *
  * Creates a new "blob" object wrapping @data.  The @mode parameter is used
  * to negotiate ownership and lifecycle of @data.
@@ -116,7 +113,7 @@ _hb_blob_destroy (void *data)
  * @length: Length of sub-blob.
  *
  * Returns a blob that represents a range of bytes in @parent.  The new
- * blob is always created with %HB_MEMORY_MODE_READONLY, meaning that it
+ * blob is always created with #HB_MEMORY_MODE_READONLY, meaning that it
  * will never modify data in the parent blob.  The parent data is not
  * expected to be modified, and will result in undefined behavior if it
  * is.
@@ -237,7 +234,7 @@ hb_blob_destroy (hb_blob_t *blob)
  * @blob: An #hb_blob_t
  * @key: The user-data key to set
  * @data: A pointer to the user data to set
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the specified blob.
@@ -299,7 +296,7 @@ hb_blob_make_immutable (hb_blob_t *blob)
  *
  * Tests whether a blob is immutable.
  *
- * Return value: %true if @blob is immutable, false otherwise
+ * Return value: %true if @blob is immutable, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -365,16 +362,14 @@ hb_blob_get_data (hb_blob_t *blob, unsigned int *length)
 char *
 hb_blob_get_data_writable (hb_blob_t *blob, unsigned int *length)
 {
-  if (!blob->try_make_writable ()) {
-    if (length)
-      *length = 0;
-
+  if (hb_object_is_immutable (blob) ||
+     !blob->try_make_writable ())
+  {
+    if (length) *length = 0;
     return nullptr;
   }
 
-  if (length)
-    *length = blob->length;
-
+  if (length) *length = blob->length;
   return const_cast<char *> (blob->data);
 }
 
@@ -440,8 +435,8 @@ hb_blob_t::try_make_writable_inplace ()
 bool
 hb_blob_t::try_make_writable ()
 {
-  if (hb_object_is_immutable (this))
-    return false;
+  if (unlikely (!length))
+    mode = HB_MEMORY_MODE_WRITABLE;
 
   if (this->mode == HB_MEMORY_MODE_WRITABLE)
     return true;
diff --git a/thirdparty/harfbuzz/src/hb-blob.h b/thirdparty/harfbuzz/src/hb-blob.h
index 00e41f3ce3..86f12788d2 100644
--- a/thirdparty/harfbuzz/src/hb-blob.h
+++ b/thirdparty/harfbuzz/src/hb-blob.h
@@ -24,7 +24,7 @@
  * Red Hat Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -38,10 +38,12 @@ HB_BEGIN_DECLS
 
 /**
  * hb_memory_mode_t:
- * @HB_MEMORY_MODE_DUPLICATE
- * @HB_MEMORY_MODE_READONLY
- * @HB_MEMORY_MODE_WRITABLE
- * @HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE
+ * @HB_MEMORY_MODE_DUPLICATE: HarfBuzz immediately makes a copy of the data.
+ * @HB_MEMORY_MODE_READONLY: HarfBuzz client will never modify the data,
+ *     and HarfBuzz will never modify the data.
+ * @HB_MEMORY_MODE_WRITABLE: HarfBuzz client made a copy of the data solely
+ *     for HarfBuzz, so HarfBuzz may modify the data.
+ * @HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE: See above
  *
  * Data type holding the memory modes available to
  * client programs.
diff --git a/thirdparty/harfbuzz/src/hb-buffer-serialize.cc b/thirdparty/harfbuzz/src/hb-buffer-serialize.cc
index f65bad45bb..6539b89640 100644
--- a/thirdparty/harfbuzz/src/hb-buffer-serialize.cc
+++ b/thirdparty/harfbuzz/src/hb-buffer-serialize.cc
@@ -400,8 +400,8 @@ _hb_buffer_serialize_unicode_text (hb_buffer_t *buffer,
  * @buf: (out) (array length=buf_size) (element-type uint8_t): output string to
  *       write serialized buffer into.
  * @buf_size: the size of @buf.
- * @buf_consumed: (out) (allow-none): if not %NULL, will be set to the number of byes written into @buf.
- * @font: (allow-none): the #hb_font_t used to shape this buffer, needed to
+ * @buf_consumed: (out) (optional): if not %NULL, will be set to the number of byes written into @buf.
+ * @font: (nullable): the #hb_font_t used to shape this buffer, needed to
  *        read glyph names and extents. If %NULL, and empty font will be used.
  * @format: the #hb_buffer_serialize_format_t to use for formatting the output.
  * @flags: the #hb_buffer_serialize_flags_t that control what glyph properties
@@ -514,8 +514,10 @@ hb_buffer_serialize_glyphs (hb_buffer_t *buffer,
  * @buf: (out) (array length=buf_size) (element-type uint8_t): output string to
  *       write serialized buffer into.
  * @buf_size: the size of @buf.
- * @buf_consumed: (out) (allow-none): if not %NULL, will be set to the number of byes written into @buf.
+ * @buf_consumed: (out) (optional): if not %NULL, will be set to the number of byes written into @buf.
  * @format: the #hb_buffer_serialize_format_t to use for formatting the output.
+ * @flags: the #hb_buffer_serialize_flags_t that control what glyph properties
+ *         to serialize.
  *
  * Serializes @buffer into a textual representation of its content,
  * when the buffer contains Unicode codepoints (i.e., before shaping). This is
@@ -635,8 +637,8 @@ _hb_buffer_serialize_invalid (hb_buffer_t *buffer,
  * @buf: (out) (array length=buf_size) (element-type uint8_t): output string to
  *       write serialized buffer into.
  * @buf_size: the size of @buf.
- * @buf_consumed: (out) (allow-none): if not %NULL, will be set to the number of byes written into @buf.
- * @font: (allow-none): the #hb_font_t used to shape this buffer, needed to
+ * @buf_consumed: (out) (optional): if not %NULL, will be set to the number of byes written into @buf.
+ * @font: (nullable): the #hb_font_t used to shape this buffer, needed to
  *        read glyph names and extents. If %NULL, and empty font will be used.
  * @format: the #hb_buffer_serialize_format_t to use for formatting the output.
  * @flags: the #hb_buffer_serialize_flags_t that control what glyph properties
@@ -724,15 +726,17 @@ parse_hex (const char *pp, const char *end, uint32_t *pv)
 /**
  * hb_buffer_deserialize_glyphs:
  * @buffer: an #hb_buffer_t buffer.
- * @buf: (array length=buf_len):
- * @buf_len:
- * @end_ptr: (out):
- * @font:
- * @format:
- *
+ * @buf: (array length=buf_len): string to deserialize
+ * @buf_len: the size of @buf, or -1 if it is %NULL-terminated
+ * @end_ptr: (out) (optional): output pointer to the character after last
+ *                               consumed one.
+ * @font: (nullable): font for getting glyph IDs
+ * @format: the #hb_buffer_serialize_format_t of the input @buf
  *
+ * Deserializes glyphs @buffer from textual representation in the format
+ * produced by hb_buffer_serialize_glyphs().
  *
- * Return value:
+ * Return value: %true if @buf is not fully consumed, %false otherwise.
  *
  * Since: 0.9.7
  **/
@@ -795,14 +799,16 @@ hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,
 /**
  * hb_buffer_deserialize_unicode:
  * @buffer: an #hb_buffer_t buffer.
- * @buf: (array length=buf_len):
- * @buf_len:
- * @end_ptr: (out):
- * @format:
- *
+ * @buf: (array length=buf_len): string to deserialize
+ * @buf_len: the size of @buf, or -1 if it is %NULL-terminated
+ * @end_ptr: (out) (optional): output pointer to the character after last
+ *                               consumed one.
+ * @format: the #hb_buffer_serialize_format_t of the input @buf
  *
+ * Deserializes Unicode @buffer from textual representation in the format
+ * produced by hb_buffer_serialize_unicode().
  *
- * Return value:
+ * Return value: %true if @buf is not fully consumed, %false otherwise.
  *
  * Since: 2.7.3
  **/
diff --git a/thirdparty/harfbuzz/src/hb-buffer.cc b/thirdparty/harfbuzz/src/hb-buffer.cc
index 10063db050..8cad6ab8e6 100644
--- a/thirdparty/harfbuzz/src/hb-buffer.cc
+++ b/thirdparty/harfbuzz/src/hb-buffer.cc
@@ -218,9 +218,6 @@ hb_buffer_t::get_scratch_buffer (unsigned int *size)
 void
 hb_buffer_t::reset ()
 {
-  if (unlikely (hb_object_is_immutable (this)))
-    return;
-
   hb_unicode_funcs_destroy (unicode);
   unicode = hb_unicode_funcs_reference (hb_unicode_funcs_get_default ());
   flags = HB_BUFFER_FLAG_DEFAULT;
@@ -233,9 +230,6 @@ hb_buffer_t::reset ()
 void
 hb_buffer_t::clear ()
 {
-  if (unlikely (hb_object_is_immutable (this)))
-    return;
-
   hb_segment_properties_t default_props = HB_SEGMENT_PROPERTIES_DEFAULT;
   props = default_props;
   scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
@@ -290,9 +284,6 @@ hb_buffer_t::add_info (const hb_glyph_info_t &glyph_info)
 void
 hb_buffer_t::remove_output ()
 {
-  if (unlikely (hb_object_is_immutable (this)))
-    return;
-
   have_output = false;
   have_positions = false;
 
@@ -303,9 +294,6 @@ hb_buffer_t::remove_output ()
 void
 hb_buffer_t::clear_output ()
 {
-  if (unlikely (hb_object_is_immutable (this)))
-    return;
-
   have_output = true;
   have_positions = false;
 
@@ -316,9 +304,6 @@ hb_buffer_t::clear_output ()
 void
 hb_buffer_t::clear_positions ()
 {
-  if (unlikely (hb_object_is_immutable (this)))
-    return;
-
   have_output = false;
   have_positions = true;
 
@@ -333,15 +318,19 @@ hb_buffer_t::swap_buffers ()
 {
   if (unlikely (!successful)) return;
 
+  assert (idx <= len);
+  if (unlikely (!next_glyphs (len - idx))) return;
+
   assert (have_output);
   have_output = false;
 
   if (out_info != info)
   {
-    hb_glyph_info_t *tmp_string;
-    tmp_string = info;
+    hb_glyph_info_t *tmp;
+    tmp = info;
     info = out_info;
-    out_info = tmp_string;
+    out_info = tmp;
+
     pos = (hb_glyph_position_t *) out_info;
   }
 
@@ -353,31 +342,6 @@ hb_buffer_t::swap_buffers ()
   idx = 0;
 }
 
-
-void
-hb_buffer_t::replace_glyphs (unsigned int num_in,
-			     unsigned int num_out,
-			     const uint32_t *glyph_data)
-{
-  if (unlikely (!make_room_for (num_in, num_out))) return;
-
-  assert (idx + num_in <= len);
-
-  merge_clusters (idx, idx + num_in);
-
-  hb_glyph_info_t orig_info = info[idx];
-  hb_glyph_info_t *pinfo = &out_info[out_len];
-  for (unsigned int i = 0; i < num_out; i++)
-  {
-    *pinfo = orig_info;
-    pinfo->codepoint = glyph_data[i];
-    pinfo++;
-  }
-
-  idx  += num_in;
-  out_len += num_out;
-}
-
 bool
 hb_buffer_t::move_to (unsigned int i)
 {
@@ -768,7 +732,7 @@ hb_buffer_destroy (hb_buffer_t *buffer)
  * @buffer: An #hb_buffer_t
  * @key: The user-data key
  * @data: A pointer to the user data
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the specified buffer. 
@@ -795,7 +759,7 @@ hb_buffer_set_user_data (hb_buffer_t        *buffer,
  * Fetches the user data associated with the specified key,
  * attached to the specified buffer.
  *
- * Return value: (transfer-none): A pointer to the user data
+ * Return value: (transfer none): A pointer to the user data
  *
  * Since: 0.9.2
  **/
@@ -1137,7 +1101,7 @@ hb_buffer_get_cluster_level (hb_buffer_t *buffer)
  * Sets the #hb_codepoint_t that replaces invalid entries for a given encoding
  * when adding text to @buffer.
  *
- * Default is %HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT.
+ * Default is #HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT.
  *
  * Since: 0.9.31
  **/
@@ -1222,6 +1186,9 @@ hb_buffer_get_invisible_glyph (hb_buffer_t    *buffer)
 void
 hb_buffer_reset (hb_buffer_t *buffer)
 {
+  if (unlikely (hb_object_is_immutable (buffer)))
+    return;
+
   buffer->reset ();
 }
 
@@ -1237,6 +1204,9 @@ hb_buffer_reset (hb_buffer_t *buffer)
 void
 hb_buffer_clear_contents (hb_buffer_t *buffer)
 {
+  if (unlikely (hb_object_is_immutable (buffer)))
+    return;
+
   buffer->clear ();
 }
 
@@ -1321,7 +1291,7 @@ hb_buffer_set_length (hb_buffer_t  *buffer,
   if (unlikely (hb_object_is_immutable (buffer)))
     return length == 0;
 
-  if (!buffer->ensure (length))
+  if (unlikely (!buffer->ensure (length)))
     return false;
 
   /* Wipe the new space */
@@ -1501,20 +1471,20 @@ hb_buffer_reverse_clusters (hb_buffer_t *buffer)
  *
  * Sets unset buffer segment properties based on buffer Unicode
  * contents.  If buffer is not empty, it must have content type
- * %HB_BUFFER_CONTENT_TYPE_UNICODE.
+ * #HB_BUFFER_CONTENT_TYPE_UNICODE.
  *
- * If buffer script is not set (ie. is %HB_SCRIPT_INVALID), it
+ * If buffer script is not set (ie. is #HB_SCRIPT_INVALID), it
  * will be set to the Unicode script of the first character in
- * the buffer that has a script other than %HB_SCRIPT_COMMON,
- * %HB_SCRIPT_INHERITED, and %HB_SCRIPT_UNKNOWN.
+ * the buffer that has a script other than #HB_SCRIPT_COMMON,
+ * #HB_SCRIPT_INHERITED, and #HB_SCRIPT_UNKNOWN.
  *
- * Next, if buffer direction is not set (ie. is %HB_DIRECTION_INVALID),
+ * Next, if buffer direction is not set (ie. is #HB_DIRECTION_INVALID),
  * it will be set to the natural horizontal direction of the
  * buffer script as returned by hb_script_get_horizontal_direction().
- * If hb_script_get_horizontal_direction() returns %HB_DIRECTION_INVALID,
- * then %HB_DIRECTION_LTR is used.
+ * If hb_script_get_horizontal_direction() returns #HB_DIRECTION_INVALID,
+ * then #HB_DIRECTION_LTR is used.
  *
- * Finally, if buffer language is not set (ie. is %HB_LANGUAGE_INVALID),
+ * Finally, if buffer language is not set (ie. is #HB_LANGUAGE_INVALID),
  * it will be set to the process's default language as returned by
  * hb_language_get_default().  This may change in the future by
  * taking buffer script into consideration when choosing a language.
@@ -1551,7 +1521,10 @@ hb_buffer_add_utf (hb_buffer_t  *buffer,
   if (item_length == -1)
     item_length = text_length - item_offset;
 
-  buffer->ensure (buffer->len + item_length * sizeof (T) / 4);
+  if (unlikely (item_length < 0 ||
+		item_length > INT_MAX / 8 ||
+		!buffer->ensure (buffer->len + item_length * sizeof (T) / 4)))
+    return;
 
   /* If buffer is empty and pre-context provided, install it.
    * This check is written this way, to make sure people can
@@ -1768,11 +1741,6 @@ hb_buffer_append (hb_buffer_t *buffer,
   if (start == end)
     return;
 
-  if (!buffer->len)
-    buffer->content_type = source->content_type;
-  if (!buffer->have_positions && source->have_positions)
-    buffer->clear_positions ();
-
   if (buffer->len + (end - start) < buffer->len) /* Overflows. */
   {
     buffer->successful = false;
@@ -1784,6 +1752,11 @@ hb_buffer_append (hb_buffer_t *buffer,
   if (unlikely (!buffer->successful))
     return;
 
+  if (!orig_len)
+    buffer->content_type = source->content_type;
+  if (!buffer->have_positions && source->have_positions)
+    buffer->clear_positions ();
+
   memcpy (buffer->info + orig_len, source->info + start, (end - start) * sizeof (buffer->info[0]));
   if (buffer->have_positions)
     memcpy (buffer->pos + orig_len, source->pos + start, (end - start) * sizeof (buffer->pos[0]));
@@ -1902,8 +1875,8 @@ hb_buffer_t::sort (unsigned int start, unsigned int end, int(*compar)(const hb_g
  * @dottedcircle_glyph: glyph id of U+25CC DOTTED CIRCLE, or (hb_codepont_t) -1.
  * @position_fuzz: allowed absolute difference in position values.
  *
- * If dottedcircle_glyph is (hb_codepoint_t) -1 then %HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT
- * and %HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT are never returned.  This should be used by most
+ * If dottedcircle_glyph is (hb_codepoint_t) -1 then #HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT
+ * and #HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT are never returned.  This should be used by most
  * callers if just comparing two buffers is needed.
  *
  * Since: 1.5.0
@@ -1994,11 +1967,11 @@ hb_buffer_diff (hb_buffer_t *buffer,
 /**
  * hb_buffer_set_message_func:
  * @buffer: An #hb_buffer_t
- * @func: (closure user_data) (destroy destroy) (scope notified):
- * @user_data:
- * @destroy:
- *
+ * @func: (closure user_data) (destroy destroy) (scope notified): Callback function
+ * @user_data: (nullable): Data to pass to @func
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
+ * Sets the implementation function for #hb_buffer_message_func_t.
  *
  * Since: 1.1.3
  **/
diff --git a/thirdparty/harfbuzz/src/hb-buffer.h b/thirdparty/harfbuzz/src/hb-buffer.h
index b13757e68f..865ccb2273 100644
--- a/thirdparty/harfbuzz/src/hb-buffer.h
+++ b/thirdparty/harfbuzz/src/hb-buffer.h
@@ -27,7 +27,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -90,6 +90,8 @@ typedef struct hb_glyph_info_t {
  * 				   breaking point only.
  * @HB_GLYPH_FLAG_DEFINED: All the currently defined flags.
  *
+ * Flags for #hb_glyph_info_t.
+ *
  * Since: 1.5.0
  */
 typedef enum { /*< flags >*/
@@ -150,6 +152,11 @@ typedef struct hb_segment_properties_t {
   void           *reserved2;
 } hb_segment_properties_t;
 
+/**
+ * HB_SEGMENT_PROPERTIES_DEFAULT:
+ *
+ * The default #hb_segment_properties_t of of freshly created #hb_buffer_t.
+ */
 #define HB_SEGMENT_PROPERTIES_DEFAULT {HB_DIRECTION_INVALID, \
 				       HB_SCRIPT_INVALID, \
 				       HB_LANGUAGE_INVALID, \
@@ -203,6 +210,8 @@ hb_buffer_get_user_data (hb_buffer_t        *buffer,
  * @HB_BUFFER_CONTENT_TYPE_INVALID: Initial value for new buffer.
  * @HB_BUFFER_CONTENT_TYPE_UNICODE: The buffer contains input characters (before shaping).
  * @HB_BUFFER_CONTENT_TYPE_GLYPHS: The buffer contains output glyphs (after shaping).
+ *
+ * The type of #hb_buffer_t contents.
  */
 typedef enum {
   HB_BUFFER_CONTENT_TYPE_INVALID = 0,
@@ -288,6 +297,8 @@ hb_buffer_guess_segment_properties (hb_buffer_t *buffer);
  *                      not be inserted in the rendering of incorrect
  *                      character sequences (such at <0905 093E>). Since: 2.4
  *
+ * Flags for #hb_buffer_t.
+ *
  * Since: 0.9.20
  */
 typedef enum { /*< flags >*/
@@ -579,6 +590,35 @@ hb_buffer_deserialize_unicode (hb_buffer_t *buffer,
  * Compare buffers
  */
 
+/**
+ * hb_buffer_diff_flags_t:
+ * @HB_BUFFER_DIFF_FLAG_EQUAL: equal buffers.
+ * @HB_BUFFER_DIFF_FLAG_CONTENT_TYPE_MISMATCH: buffers with different
+ *     #hb_buffer_content_type_t.
+ * @HB_BUFFER_DIFF_FLAG_LENGTH_MISMATCH: buffers with differing length.
+ * @HB_BUFFER_DIFF_FLAG_NOTDEF_PRESENT: `.notdef` glyph is present in the
+ *     reference buffer.
+ * @HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT: dotted circle glyph is present
+ *     in the reference buffer.
+ * @HB_BUFFER_DIFF_FLAG_CODEPOINT_MISMATCH: difference in #hb_glyph_info_t.codepoint
+ * @HB_BUFFER_DIFF_FLAG_CLUSTER_MISMATCH: difference in #hb_glyph_info_t.cluster
+ * @HB_BUFFER_DIFF_FLAG_GLYPH_FLAGS_MISMATCH: difference in #hb_glyph_flags_t.
+ * @HB_BUFFER_DIFF_FLAG_POSITION_MISMATCH: difference in #hb_glyph_position_t.
+ *
+ * Flags from comparing two #hb_buffer_t's.
+ *
+ * Buffer with different #hb_buffer_content_type_t cannot be meaningfully
+ * compared in any further detail.
+ *
+ * For buffers with differing length, the per-glyph comparison is not
+ * attempted, though we do still scan reference buffer for dotted circle and
+ * `.notdef` glyphs.
+ *
+ * If the buffers have the same length, we compare them glyph-by-glyph and
+ * report which aspect(s) of the glyph info/position are different.
+ *
+ * Since: 1.5.0
+ */
 typedef enum { /*< flags >*/
   HB_BUFFER_DIFF_FLAG_EQUAL			= 0x0000,
 
@@ -618,6 +658,23 @@ hb_buffer_diff (hb_buffer_t *buffer,
  * Debugging.
  */
 
+/**
+ * hb_buffer_message_func_t:
+ * @buffer: An #hb_buffer_t to work upon
+ * @font: The #hb_font_t the @buffer is shaped with
+ * @message: %NULL-terminated message passed to the function
+ * @user_data: User data pointer passed by the caller
+ *
+ * A callback method for #hb_buffer_t. The method gets called with the
+ * #hb_buffer_t it was set on, the #hb_font_t the buffer is shaped with and a
+ * message describing what step of the shaping process will be performed.
+ * Returning %false from this method will skip this shaping step and move to
+ * the next one.
+ *
+ * Return value: %true to perform the shaping step, %false to skip it.
+ *
+ * Since: 1.1.3
+ */
 typedef hb_bool_t	(*hb_buffer_message_func_t)	(hb_buffer_t *buffer,
 							 hb_font_t   *font,
 							 const char  *message,
diff --git a/thirdparty/harfbuzz/src/hb-buffer.hh b/thirdparty/harfbuzz/src/hb-buffer.hh
index 9cad5206e2..8b432b5f96 100644
--- a/thirdparty/harfbuzz/src/hb-buffer.hh
+++ b/thirdparty/harfbuzz/src/hb-buffer.hh
@@ -139,7 +139,7 @@ struct hb_buffer_t
 
   /* Methods */
 
-  bool in_error () const { return !successful; }
+  HB_NODISCARD bool in_error () const { return !successful; }
 
   void allocate_var (unsigned int start, unsigned int count)
   {
@@ -186,7 +186,7 @@ struct hb_buffer_t
   hb_glyph_info_t &prev ()      { return out_info[out_len ? out_len - 1 : 0]; }
   hb_glyph_info_t prev () const { return out_info[out_len ? out_len - 1 : 0]; }
 
-  bool has_separate_output () const { return info != out_info; }
+  HB_NODISCARD bool has_separate_output () const { return info != out_info; }
 
 
   HB_INTERNAL void reset ();
@@ -210,86 +210,89 @@ struct hb_buffer_t
   HB_INTERNAL void clear_output ();
   HB_INTERNAL void clear_positions ();
 
-  HB_INTERNAL void replace_glyphs (unsigned int num_in,
-				   unsigned int num_out,
-				   const hb_codepoint_t *glyph_data);
-
-  void replace_glyph (hb_codepoint_t glyph_index)
+  template <typename T>
+  HB_NODISCARD bool replace_glyphs (unsigned int num_in,
+				    unsigned int num_out,
+				    const T *glyph_data)
   {
-    if (unlikely (out_info != info || out_len != idx)) {
-      if (unlikely (!make_room_for (1, 1))) return;
-      out_info[out_len] = info[idx];
-    }
-    out_info[out_len].codepoint = glyph_index;
+    if (unlikely (!make_room_for (num_in, num_out))) return false;
 
-    idx++;
-    out_len++;
-  }
-  /* Makes a copy of the glyph at idx to output and replace glyph_index */
-  hb_glyph_info_t & output_glyph (hb_codepoint_t glyph_index)
-  {
-    if (unlikely (!make_room_for (0, 1))) return Crap (hb_glyph_info_t);
+    assert (idx + num_in <= len);
 
-    if (unlikely (idx == len && !out_len))
-      return Crap (hb_glyph_info_t);
+    merge_clusters (idx, idx + num_in);
 
-    out_info[out_len] = idx < len ? info[idx] : out_info[out_len - 1];
-    out_info[out_len].codepoint = glyph_index;
+    hb_glyph_info_t &orig_info = idx < len ? cur() : prev();
 
-    out_len++;
+    hb_glyph_info_t *pinfo = &out_info[out_len];
+    for (unsigned int i = 0; i < num_out; i++)
+    {
+      *pinfo = orig_info;
+      pinfo->codepoint = glyph_data[i];
+      pinfo++;
+    }
 
-    return out_info[out_len - 1];
+    idx  += num_in;
+    out_len += num_out;
+    return true;
   }
-  void output_info (const hb_glyph_info_t &glyph_info)
+
+  HB_NODISCARD bool replace_glyph (hb_codepoint_t glyph_index)
+  { return replace_glyphs (1, 1, &glyph_index); }
+
+  /* Makes a copy of the glyph at idx to output and replace glyph_index */
+  HB_NODISCARD bool output_glyph (hb_codepoint_t glyph_index)
+  { return replace_glyphs (0, 1, &glyph_index); }
+
+  HB_NODISCARD bool output_info (const hb_glyph_info_t &glyph_info)
   {
-    if (unlikely (!make_room_for (0, 1))) return;
+    if (unlikely (!make_room_for (0, 1))) return false;
 
     out_info[out_len] = glyph_info;
 
     out_len++;
+    return true;
   }
   /* Copies glyph at idx to output but doesn't advance idx */
-  void copy_glyph ()
+  HB_NODISCARD bool copy_glyph ()
   {
-    if (unlikely (!make_room_for (0, 1))) return;
-
-    out_info[out_len] = info[idx];
-
-    out_len++;
+    /* Extra copy because cur()'s return can be freed within
+     * output_info() call if buffer reallocates. */
+    return output_info (hb_glyph_info_t (cur()));
   }
+
   /* Copies glyph at idx to output and advance idx.
    * If there's no output, just advance idx. */
-  void
-  next_glyph ()
+  HB_NODISCARD bool next_glyph ()
   {
     if (have_output)
     {
       if (out_info != info || out_len != idx)
       {
-	if (unlikely (!make_room_for (1, 1))) return;
+	if (unlikely (!make_room_for (1, 1))) return false;
 	out_info[out_len] = info[idx];
       }
       out_len++;
     }
 
     idx++;
+    return true;
   }
   /* Copies n glyphs at idx to output and advance idx.
    * If there's no output, just advance idx. */
-  void
-  next_glyphs (unsigned int n)
+  HB_NODISCARD bool next_glyphs (unsigned int n)
   {
     if (have_output)
     {
       if (out_info != info || out_len != idx)
       {
-	if (unlikely (!make_room_for (n, n))) return;
+	if (unlikely (!make_room_for (n, n))) return false;
 	memmove (out_info + out_len, info + idx, n * sizeof (out_info[0]));
       }
       out_len += n;
     }
 
     idx += n;
+    return true;
   }
   /* Advance idx without copying to output. */
   void skip_glyph () { idx++; }
@@ -329,14 +332,14 @@ struct hb_buffer_t
 
 
   /* Internal methods */
-  HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
+  HB_NODISCARD HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
 
-  HB_INTERNAL bool enlarge (unsigned int size);
+  HB_NODISCARD HB_INTERNAL bool enlarge (unsigned int size);
 
-  bool ensure (unsigned int size)
+  HB_NODISCARD bool ensure (unsigned int size)
   { return likely (!size || size < allocated) ? true : enlarge (size); }
 
-  bool ensure_inplace (unsigned int size)
+  HB_NODISCARD bool ensure_inplace (unsigned int size)
   { return likely (!size || size < allocated); }
 
   void assert_glyphs ()
@@ -349,7 +352,7 @@ struct hb_buffer_t
     assert ((content_type == HB_BUFFER_CONTENT_TYPE_UNICODE) ||
 	    (!len && (content_type == HB_BUFFER_CONTENT_TYPE_INVALID)));
   }
-  bool ensure_glyphs ()
+  HB_NODISCARD bool ensure_glyphs ()
   {
     if (unlikely (content_type != HB_BUFFER_CONTENT_TYPE_GLYPHS))
     {
@@ -360,7 +363,7 @@ struct hb_buffer_t
     }
     return true;
   }
-  bool ensure_unicode ()
+  HB_NODISCARD bool ensure_unicode ()
   {
     if (unlikely (content_type != HB_BUFFER_CONTENT_TYPE_UNICODE))
     {
@@ -372,8 +375,8 @@ struct hb_buffer_t
     return true;
   }
 
-  HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
-  HB_INTERNAL bool shift_forward (unsigned int count);
+  HB_NODISCARD HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
+  HB_NODISCARD HB_INTERNAL bool shift_forward (unsigned int count);
 
   typedef long scratch_buffer_t;
   HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size);
diff --git a/thirdparty/harfbuzz/src/hb-common.cc b/thirdparty/harfbuzz/src/hb-common.cc
index ddbcaa064c..7bb878b217 100644
--- a/thirdparty/harfbuzz/src/hb-common.cc
+++ b/thirdparty/harfbuzz/src/hb-common.cc
@@ -675,8 +675,8 @@ hb_version_string ()
  * Tests the library version against a minimum value,
  * as three integer components.
  *
- * Return value: True if the library is equal to or greater than
- * the test value, false otherwise
+ * Return value: %true if the library is equal to or greater than
+ * the test value, %false otherwise
  *
  * Since: 0.9.30
  **/
@@ -1003,6 +1003,21 @@ parse_one_variation (const char **pp, const char *end, hb_variation_t *variation
 
 /**
  * hb_variation_from_string:
+ * @str: (array length=len) (element-type uint8_t): a string to parse
+ * @len: length of @str, or -1 if string is %NULL terminated
+ * @variation: (out): the #hb_variation_t to initialize with the parsed values
+ *
+ * Parses a string into a #hb_variation_t.
+ *
+ * The format for specifying variation settings follows. All valid CSS
+ * font-variation-settings values other than 'normal' and 'inherited' are also
+ * accepted, though, not documented below.
+ *
+ * The format is a tag, optionally followed by an equals sign, followed by a
+ * number. For example `wght=500`, or `slnt=-7.5`.
+ *
+ * Return value:
+ * %true if @str is successfully parsed, %false otherwise
  *
  * Since: 1.4.2
  */
@@ -1029,6 +1044,13 @@ hb_variation_from_string (const char *str, int len,
 
 /**
  * hb_variation_to_string:
+ * @variation: an #hb_variation_t to convert
+ * @buf: (array length=size) (out): output string
+ * @size: the allocated size of @buf
+ *
+ * Converts an #hb_variation_t into a %NULL-terminated string in the format
+ * understood by hb_variation_from_string(). The client in responsible for
+ * allocating big enough size for @buf, 128 bytes is more than enough.
  *
  * Since: 1.4.2
  */
@@ -1055,9 +1077,11 @@ hb_variation_to_string (hb_variation_t *variation,
 
 /**
  * hb_color_get_alpha:
- * color: a #hb_color_t we are interested in its channels.
+ * @color: an #hb_color_t we are interested in its channels.
  *
- * Return value: Alpha channel value of the given color
+ * Fetches the alpha channel of the given @color.
+ *
+ * Return value: Alpha channel value
  *
  * Since: 2.1.0
  */
@@ -1069,9 +1093,11 @@ uint8_t
 
 /**
  * hb_color_get_red:
- * color: a #hb_color_t we are interested in its channels.
+ * @color: an #hb_color_t we are interested in its channels.
+ *
+ * Fetches the red channel of the given @color.
  *
- * Return value: Red channel value of the given color
+ * Return value: Red channel value
  *
  * Since: 2.1.0
  */
@@ -1083,9 +1109,11 @@ uint8_t
 
 /**
  * hb_color_get_green:
- * color: a #hb_color_t we are interested in its channels.
+ * @color: an #hb_color_t we are interested in its channels.
  *
- * Return value: Green channel value of the given color
+ * Fetches the green channel of the given @color.
+ *
+ * Return value: Green channel value
  *
  * Since: 2.1.0
  */
@@ -1097,9 +1125,11 @@ uint8_t
 
 /**
  * hb_color_get_blue:
- * color: a #hb_color_t we are interested in its channels.
+ * @color: an #hb_color_t we are interested in its channels.
+ *
+ * Fetches the blue channel of the given @color.
  *
- * Return value: Blue channel value of the given color
+ * Return value: Blue channel value
  *
  * Since: 2.1.0
  */
diff --git a/thirdparty/harfbuzz/src/hb-common.h b/thirdparty/harfbuzz/src/hb-common.h
index efe185cdfd..532fd428cb 100644
--- a/thirdparty/harfbuzz/src/hb-common.h
+++ b/thirdparty/harfbuzz/src/hb-common.h
@@ -26,7 +26,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -135,7 +135,7 @@ typedef union _hb_var_int_t {
 
 /**
  * hb_tag_t:
- * 
+ *
  * Data type for tag identifiers. Tags are four
  * byte integers, each byte representing a character.
  *
@@ -148,22 +148,48 @@ typedef uint32_t hb_tag_t;
 
 /**
  * HB_TAG:
+ * @c1: 1st character of the tag
+ * @c2: 2nd character of the tag
+ * @c3: 3rd character of the tag
+ * @c4: 4th character of the tag
  *
- * Constructs an #hb_tag_t from four characters.
+ * Constructs an #hb_tag_t from four character literals.
  *
  **/
 #define HB_TAG(c1,c2,c3,c4) ((hb_tag_t)((((uint32_t)(c1)&0xFF)<<24)|(((uint32_t)(c2)&0xFF)<<16)|(((uint32_t)(c3)&0xFF)<<8)|((uint32_t)(c4)&0xFF)))
 
 /**
  * HB_UNTAG:
+ * @tag: an #hb_tag_t
+ *
+ * Extracts four character literals from an #hb_tag_t.
  *
- * Extracts the characters from an #hb_tag_t.
+ * Since: 0.6.0
  *
  **/
 #define HB_UNTAG(tag)   (uint8_t)(((tag)>>24)&0xFF), (uint8_t)(((tag)>>16)&0xFF), (uint8_t)(((tag)>>8)&0xFF), (uint8_t)((tag)&0xFF)
 
+/**
+ * HB_TAG_NONE:
+ *
+ * Unset #hb_tag_t.
+ */
 #define HB_TAG_NONE HB_TAG(0,0,0,0)
+/**
+ * HB_TAG_MAX:
+ *
+ * Maximum possible unsigned #hb_tag_t.
+ *
+ * Since: 0.9.26
+ */
 #define HB_TAG_MAX HB_TAG(0xff,0xff,0xff,0xff)
+/**
+ * HB_TAG_MAX_SIGNED:
+ *
+ * Maximum possible signed #hb_tag_t.
+ *
+ * Since: 0.9.33
+ */
 #define HB_TAG_MAX_SIGNED HB_TAG(0x7f,0xff,0xff,0xff)
 
 /* len=-1 means str is NUL-terminated. */
@@ -263,6 +289,13 @@ hb_direction_to_string (hb_direction_t direction);
 
 /* hb_language_t */
 
+/**
+ * hb_language_t:
+ *
+ * Data type for languages. Each #hb_language_t corresponds to a BCP 47
+ * language tag.
+ *
+ */
 typedef const struct hb_language_impl_t *hb_language_t;
 
 HB_EXTERN hb_language_t
@@ -271,6 +304,13 @@ hb_language_from_string (const char *str, int len);
 HB_EXTERN const char *
 hb_language_to_string (hb_language_t language);
 
+/**
+ * HB_LANGUAGE_INVALID:
+ *
+ * An unset #hb_language_t.
+ *
+ * Since: 0.6.0
+ */
 #define HB_LANGUAGE_INVALID ((hb_language_t) 0)
 
 HB_EXTERN hb_language_t
@@ -279,160 +319,164 @@ hb_language_get_default (void);
 
 /**
  * hb_script_t:
- * @HB_SCRIPT_COMMON: HB_TAG ('Z','y','y','y')
- * @HB_SCRIPT_INHERITED: HB_TAG ('Z','i','n','h')
- * @HB_SCRIPT_UNKNOWN: HB_TAG ('Z','z','z','z')
- * @HB_SCRIPT_ARABIC
- * @HB_SCRIPT_ARMENIAN
- * @HB_SCRIPT_BENGALI
- * @HB_SCRIPT_CYRILLIC
- * @HB_SCRIPT_DEVANAGARI
- * @HB_SCRIPT_GEORGIAN
- * @HB_SCRIPT_GREEK
- * @HB_SCRIPT_GUJARATI
- * @HB_SCRIPT_GURMUKHI
- * @HB_SCRIPT_HANGUL
- * @HB_SCRIPT_HAN
- * @HB_SCRIPT_HEBREW
- * @HB_SCRIPT_HIRAGANA
- * @HB_SCRIPT_KANNADA
- * @HB_SCRIPT_KATAKANA
- * @HB_SCRIPT_LAO
- * @HB_SCRIPT_LATIN
- * @HB_SCRIPT_MALAYALAM
- * @HB_SCRIPT_ORIYA
- * @HB_SCRIPT_TAMIL
- * @HB_SCRIPT_TELUGU
- * @HB_SCRIPT_THAI
- * @HB_SCRIPT_TIBETAN
- * @HB_SCRIPT_BOPOMOFO
- * @HB_SCRIPT_BRAILLE
- * @HB_SCRIPT_CANADIAN_SYLLABICS
- * @HB_SCRIPT_CHEROKEE
- * @HB_SCRIPT_ETHIOPIC
- * @HB_SCRIPT_KHMER
- * @HB_SCRIPT_MONGOLIAN
- * @HB_SCRIPT_MYANMAR
- * @HB_SCRIPT_OGHAM
- * @HB_SCRIPT_RUNIC
- * @HB_SCRIPT_SINHALA
- * @HB_SCRIPT_SYRIAC
- * @HB_SCRIPT_THAANA
- * @HB_SCRIPT_YI
- * @HB_SCRIPT_DESERET
- * @HB_SCRIPT_GOTHIC
- * @HB_SCRIPT_OLD_ITALIC
- * @HB_SCRIPT_BUHID
- * @HB_SCRIPT_HANUNOO
- * @HB_SCRIPT_TAGALOG
- * @HB_SCRIPT_TAGBANWA
- * @HB_SCRIPT_CYPRIOT
- * @HB_SCRIPT_LIMBU
- * @HB_SCRIPT_LINEAR_B
- * @HB_SCRIPT_OSMANYA
- * @HB_SCRIPT_SHAVIAN
- * @HB_SCRIPT_TAI_LE
- * @HB_SCRIPT_UGARITIC
- * @HB_SCRIPT_BUGINESE
- * @HB_SCRIPT_COPTIC
- * @HB_SCRIPT_GLAGOLITIC
- * @HB_SCRIPT_KHAROSHTHI
- * @HB_SCRIPT_NEW_TAI_LUE
- * @HB_SCRIPT_OLD_PERSIAN
- * @HB_SCRIPT_SYLOTI_NAGRI
- * @HB_SCRIPT_TIFINAGH
- * @HB_SCRIPT_BALINESE
- * @HB_SCRIPT_CUNEIFORM
- * @HB_SCRIPT_NKO
- * @HB_SCRIPT_PHAGS_PA
- * @HB_SCRIPT_PHOENICIAN
- * @HB_SCRIPT_CARIAN
- * @HB_SCRIPT_CHAM
- * @HB_SCRIPT_KAYAH_LI
- * @HB_SCRIPT_LEPCHA
- * @HB_SCRIPT_LYCIAN
- * @HB_SCRIPT_LYDIAN
- * @HB_SCRIPT_OL_CHIKI
- * @HB_SCRIPT_REJANG
- * @HB_SCRIPT_SAURASHTRA
- * @HB_SCRIPT_SUNDANESE
- * @HB_SCRIPT_VAI
- * @HB_SCRIPT_AVESTAN
- * @HB_SCRIPT_BAMUM
- * @HB_SCRIPT_EGYPTIAN_HIEROGLYPHS
- * @HB_SCRIPT_IMPERIAL_ARAMAIC
- * @HB_SCRIPT_INSCRIPTIONAL_PAHLAVI
- * @HB_SCRIPT_INSCRIPTIONAL_PARTHIAN
- * @HB_SCRIPT_JAVANESE
- * @HB_SCRIPT_KAITHI
- * @HB_SCRIPT_LISU
- * @HB_SCRIPT_MEETEI_MAYEK
- * @HB_SCRIPT_OLD_SOUTH_ARABIAN
- * @HB_SCRIPT_OLD_TURKIC
- * @HB_SCRIPT_SAMARITAN
- * @HB_SCRIPT_TAI_THAM
- * @HB_SCRIPT_TAI_VIET
- * @HB_SCRIPT_BATAK
- * @HB_SCRIPT_BRAHMI
- * @HB_SCRIPT_MANDAIC
- * @HB_SCRIPT_CHAKMA
- * @HB_SCRIPT_MEROITIC_CURSIVE
- * @HB_SCRIPT_MEROITIC_HIEROGLYPHS
- * @HB_SCRIPT_MIAO
- * @HB_SCRIPT_SHARADA
- * @HB_SCRIPT_SORA_SOMPENG
- * @HB_SCRIPT_TAKRI
- * @HB_SCRIPT_BASSA_VAH
- * @HB_SCRIPT_CAUCASIAN_ALBANIAN
- * @HB_SCRIPT_DUPLOYAN
- * @HB_SCRIPT_ELBASAN
- * @HB_SCRIPT_GRANTHA
- * @HB_SCRIPT_KHOJKI
- * @HB_SCRIPT_KHUDAWADI
- * @HB_SCRIPT_LINEAR_A
- * @HB_SCRIPT_MAHAJANI
- * @HB_SCRIPT_MANICHAEAN
- * @HB_SCRIPT_MENDE_KIKAKUI
- * @HB_SCRIPT_MODI
- * @HB_SCRIPT_MRO
- * @HB_SCRIPT_NABATAEAN
- * @HB_SCRIPT_OLD_NORTH_ARABIAN
- * @HB_SCRIPT_OLD_PERMIC
- * @HB_SCRIPT_PAHAWH_HMONG
- * @HB_SCRIPT_PALMYRENE
- * @HB_SCRIPT_PAU_CIN_HAU
- * @HB_SCRIPT_PSALTER_PAHLAVI
- * @HB_SCRIPT_SIDDHAM
- * @HB_SCRIPT_TIRHUTA
- * @HB_SCRIPT_WARANG_CITI
- * @HB_SCRIPT_AHOM
- * @HB_SCRIPT_ANATOLIAN_HIEROGLYPHS
- * @HB_SCRIPT_HATRAN
- * @HB_SCRIPT_MULTANI
- * @HB_SCRIPT_OLD_HUNGARIAN
- * @HB_SCRIPT_SIGNWRITING
- * @HB_SCRIPT_ADLAM
- * @HB_SCRIPT_BHAIKSUKI
- * @HB_SCRIPT_MARCHEN
- * @HB_SCRIPT_OSAGE
- * @HB_SCRIPT_TANGUT
- * @HB_SCRIPT_NEWA
- * @HB_SCRIPT_MASARAM_GONDI
- * @HB_SCRIPT_NUSHU
- * @HB_SCRIPT_SOYOMBO
- * @HB_SCRIPT_ZANABAZAR_SQUARE
- * @HB_SCRIPT_DOGRA
- * @HB_SCRIPT_GUNJALA_GONDI
- * @HB_SCRIPT_HANIFI_ROHINGYA
- * @HB_SCRIPT_MAKASAR
- * @HB_SCRIPT_MEDEFAIDRIN
- * @HB_SCRIPT_OLD_SOGDIAN
- * @HB_SCRIPT_SOGDIAN
- * @HB_SCRIPT_ELYMAIC
- * @HB_SCRIPT_NANDINAGARI
- * @HB_SCRIPT_NYIAKENG_PUACHUE_HMONG
- * @HB_SCRIPT_WANCHO
- * @HB_SCRIPT_INVALID: #HB_TAG_NONE
+ * @HB_SCRIPT_COMMON: `Zyyy`
+ * @HB_SCRIPT_INHERITED: `Zinh`
+ * @HB_SCRIPT_UNKNOWN: `Zzzz`
+ * @HB_SCRIPT_ARABIC: `Arab`
+ * @HB_SCRIPT_ARMENIAN: `Armn`
+ * @HB_SCRIPT_BENGALI: `Beng`
+ * @HB_SCRIPT_CYRILLIC: `Cyrl`
+ * @HB_SCRIPT_DEVANAGARI: `Deva`
+ * @HB_SCRIPT_GEORGIAN: `Geor`
+ * @HB_SCRIPT_GREEK: `Grek`
+ * @HB_SCRIPT_GUJARATI: `Gujr`
+ * @HB_SCRIPT_GURMUKHI: `Guru`
+ * @HB_SCRIPT_HANGUL: `Hang`
+ * @HB_SCRIPT_HAN: `Hani`
+ * @HB_SCRIPT_HEBREW: `Hebr`
+ * @HB_SCRIPT_HIRAGANA: `Hira`
+ * @HB_SCRIPT_KANNADA: `Knda`
+ * @HB_SCRIPT_KATAKANA: `Kana`
+ * @HB_SCRIPT_LAO: `Laoo`
+ * @HB_SCRIPT_LATIN: `Latn`
+ * @HB_SCRIPT_MALAYALAM: `Mlym`
+ * @HB_SCRIPT_ORIYA: `Orya`
+ * @HB_SCRIPT_TAMIL: `Taml`
+ * @HB_SCRIPT_TELUGU: `Telu`
+ * @HB_SCRIPT_THAI: `Thai`
+ * @HB_SCRIPT_TIBETAN: `Tibt`
+ * @HB_SCRIPT_BOPOMOFO: `Bopo`
+ * @HB_SCRIPT_BRAILLE: `Brai`
+ * @HB_SCRIPT_CANADIAN_SYLLABICS: `Cans`
+ * @HB_SCRIPT_CHEROKEE: `Cher`
+ * @HB_SCRIPT_ETHIOPIC: `Ethi`
+ * @HB_SCRIPT_KHMER: `Khmr`
+ * @HB_SCRIPT_MONGOLIAN: `Mong`
+ * @HB_SCRIPT_MYANMAR: `Mymr`
+ * @HB_SCRIPT_OGHAM: `Ogam`
+ * @HB_SCRIPT_RUNIC: `Runr`
+ * @HB_SCRIPT_SINHALA: `Sinh`
+ * @HB_SCRIPT_SYRIAC: `Syrc`
+ * @HB_SCRIPT_THAANA: `Thaa`
+ * @HB_SCRIPT_YI: `Yiii`
+ * @HB_SCRIPT_DESERET: `Dsrt`
+ * @HB_SCRIPT_GOTHIC: `Goth`
+ * @HB_SCRIPT_OLD_ITALIC: `Ital`
+ * @HB_SCRIPT_BUHID: `Buhd`
+ * @HB_SCRIPT_HANUNOO: `Hano`
+ * @HB_SCRIPT_TAGALOG: `Tglg`
+ * @HB_SCRIPT_TAGBANWA: `Tagb`
+ * @HB_SCRIPT_CYPRIOT: `Cprt`
+ * @HB_SCRIPT_LIMBU: `Limb`
+ * @HB_SCRIPT_LINEAR_B: `Linb`
+ * @HB_SCRIPT_OSMANYA: `Osma`
+ * @HB_SCRIPT_SHAVIAN: `Shaw`
+ * @HB_SCRIPT_TAI_LE: `Tale`
+ * @HB_SCRIPT_UGARITIC: `Ugar`
+ * @HB_SCRIPT_BUGINESE: `Bugi`
+ * @HB_SCRIPT_COPTIC: `Copt`
+ * @HB_SCRIPT_GLAGOLITIC: `Glag`
+ * @HB_SCRIPT_KHAROSHTHI: `Khar`
+ * @HB_SCRIPT_NEW_TAI_LUE: `Talu`
+ * @HB_SCRIPT_OLD_PERSIAN: `Xpeo`
+ * @HB_SCRIPT_SYLOTI_NAGRI: `Sylo`
+ * @HB_SCRIPT_TIFINAGH: `Tfng`
+ * @HB_SCRIPT_BALINESE: `Bali`
+ * @HB_SCRIPT_CUNEIFORM: `Xsux`
+ * @HB_SCRIPT_NKO: `Nkoo`
+ * @HB_SCRIPT_PHAGS_PA: `Phag`
+ * @HB_SCRIPT_PHOENICIAN: `Phnx`
+ * @HB_SCRIPT_CARIAN: `Cari`
+ * @HB_SCRIPT_CHAM: `Cham`
+ * @HB_SCRIPT_KAYAH_LI: `Kali`
+ * @HB_SCRIPT_LEPCHA: `Lepc`
+ * @HB_SCRIPT_LYCIAN: `Lyci`
+ * @HB_SCRIPT_LYDIAN: `Lydi`
+ * @HB_SCRIPT_OL_CHIKI: `Olck`
+ * @HB_SCRIPT_REJANG: `Rjng`
+ * @HB_SCRIPT_SAURASHTRA: `Saur`
+ * @HB_SCRIPT_SUNDANESE: `Sund`
+ * @HB_SCRIPT_VAI: `Vaii`
+ * @HB_SCRIPT_AVESTAN: `Avst`
+ * @HB_SCRIPT_BAMUM: `Bamu`
+ * @HB_SCRIPT_EGYPTIAN_HIEROGLYPHS: `Egyp`
+ * @HB_SCRIPT_IMPERIAL_ARAMAIC: `Armi`
+ * @HB_SCRIPT_INSCRIPTIONAL_PAHLAVI: `Phli`
+ * @HB_SCRIPT_INSCRIPTIONAL_PARTHIAN: `Prti`
+ * @HB_SCRIPT_JAVANESE: `Java`
+ * @HB_SCRIPT_KAITHI: `Kthi`
+ * @HB_SCRIPT_LISU: `Lisu`
+ * @HB_SCRIPT_MEETEI_MAYEK: `Mtei`
+ * @HB_SCRIPT_OLD_SOUTH_ARABIAN: `Sarb`
+ * @HB_SCRIPT_OLD_TURKIC: `Orkh`
+ * @HB_SCRIPT_SAMARITAN: `Samr`
+ * @HB_SCRIPT_TAI_THAM: `Lana`
+ * @HB_SCRIPT_TAI_VIET: `Tavt`
+ * @HB_SCRIPT_BATAK: `Batk`
+ * @HB_SCRIPT_BRAHMI: `Brah`
+ * @HB_SCRIPT_MANDAIC: `Mand`
+ * @HB_SCRIPT_CHAKMA: `Cakm`
+ * @HB_SCRIPT_MEROITIC_CURSIVE: `Merc`
+ * @HB_SCRIPT_MEROITIC_HIEROGLYPHS: `Mero`
+ * @HB_SCRIPT_MIAO: `Plrd`
+ * @HB_SCRIPT_SHARADA: `Shrd`
+ * @HB_SCRIPT_SORA_SOMPENG: `Sora`
+ * @HB_SCRIPT_TAKRI: `Takr`
+ * @HB_SCRIPT_BASSA_VAH: `Bass`, Since: 0.9.30
+ * @HB_SCRIPT_CAUCASIAN_ALBANIAN: `Aghb`, Since: 0.9.30
+ * @HB_SCRIPT_DUPLOYAN: `Dupl`, Since: 0.9.30
+ * @HB_SCRIPT_ELBASAN: `Elba`, Since: 0.9.30
+ * @HB_SCRIPT_GRANTHA: `Gran`, Since: 0.9.30
+ * @HB_SCRIPT_KHOJKI: `Khoj`, Since: 0.9.30
+ * @HB_SCRIPT_KHUDAWADI: `Sind`, Since: 0.9.30
+ * @HB_SCRIPT_LINEAR_A: `Lina`, Since: 0.9.30
+ * @HB_SCRIPT_MAHAJANI: `Mahj`, Since: 0.9.30
+ * @HB_SCRIPT_MANICHAEAN: `Mani`, Since: 0.9.30
+ * @HB_SCRIPT_MENDE_KIKAKUI: `Mend`, Since: 0.9.30
+ * @HB_SCRIPT_MODI: `Modi`, Since: 0.9.30
+ * @HB_SCRIPT_MRO: `Mroo`, Since: 0.9.30
+ * @HB_SCRIPT_NABATAEAN: `Nbat`, Since: 0.9.30
+ * @HB_SCRIPT_OLD_NORTH_ARABIAN: `Narb`, Since: 0.9.30
+ * @HB_SCRIPT_OLD_PERMIC: `Perm`, Since: 0.9.30
+ * @HB_SCRIPT_PAHAWH_HMONG: `Hmng`, Since: 0.9.30
+ * @HB_SCRIPT_PALMYRENE: `Palm`, Since: 0.9.30
+ * @HB_SCRIPT_PAU_CIN_HAU: `Pauc`, Since: 0.9.30
+ * @HB_SCRIPT_PSALTER_PAHLAVI: `Phlp`, Since: 0.9.30
+ * @HB_SCRIPT_SIDDHAM: `Sidd`, Since: 0.9.30
+ * @HB_SCRIPT_TIRHUTA: `Tirh`, Since: 0.9.30
+ * @HB_SCRIPT_WARANG_CITI: `Wara`, Since: 0.9.30
+ * @HB_SCRIPT_AHOM: `Ahom`, Since: 0.9.30
+ * @HB_SCRIPT_ANATOLIAN_HIEROGLYPHS: `Hluw`, Since: 0.9.30
+ * @HB_SCRIPT_HATRAN: `Hatr`, Since: 0.9.30
+ * @HB_SCRIPT_MULTANI: `Mult`, Since: 0.9.30
+ * @HB_SCRIPT_OLD_HUNGARIAN: `Hung`, Since: 0.9.30
+ * @HB_SCRIPT_SIGNWRITING: `Sgnw`, Since: 0.9.30
+ * @HB_SCRIPT_ADLAM: `Adlm`, Since: 1.3.0
+ * @HB_SCRIPT_BHAIKSUKI: `Bhks`, Since: 1.3.0
+ * @HB_SCRIPT_MARCHEN: `Marc`, Since: 1.3.0
+ * @HB_SCRIPT_OSAGE: `Osge`, Since: 1.3.0
+ * @HB_SCRIPT_TANGUT: `Tang`, Since: 1.3.0
+ * @HB_SCRIPT_NEWA: `Newa`, Since: 1.3.0
+ * @HB_SCRIPT_MASARAM_GONDI: `Gonm`, Since: 1.6.0
+ * @HB_SCRIPT_NUSHU: `Nshu`, Since: 1.6.0
+ * @HB_SCRIPT_SOYOMBO: `Soyo`, Since: 1.6.0
+ * @HB_SCRIPT_ZANABAZAR_SQUARE: `Zanb`, Since: 1.6.0
+ * @HB_SCRIPT_DOGRA: `Dogr`, Since: 1.8.0
+ * @HB_SCRIPT_GUNJALA_GONDI: `Gong`, Since: 1.8.0
+ * @HB_SCRIPT_HANIFI_ROHINGYA: `Rohg`, Since: 1.8.0
+ * @HB_SCRIPT_MAKASAR: `Maka`, Since: 1.8.0
+ * @HB_SCRIPT_MEDEFAIDRIN: `Medf`, Since: 1.8.0
+ * @HB_SCRIPT_OLD_SOGDIAN: `Sogo`, Since: 1.8.0
+ * @HB_SCRIPT_SOGDIAN: `Sogd`, Since: 1.8.0
+ * @HB_SCRIPT_ELYMAIC: `Elym`, Since: 2.4.0
+ * @HB_SCRIPT_NANDINAGARI: `Nand`, Since: 2.4.0
+ * @HB_SCRIPT_NYIAKENG_PUACHUE_HMONG: `Hmnp`, Since: 2.4.0
+ * @HB_SCRIPT_WANCHO: `Wcho`, Since: 2.4.0
+ * @HB_SCRIPT_CHORASMIAN: `Chrs`, Since: 2.6.7
+ * @HB_SCRIPT_DIVES_AKURU: `Diak`, Since: 2.6.7
+ * @HB_SCRIPT_KHITAN_SMALL_SCRIPT: `Kits`, Since: 2.6.7
+ * @HB_SCRIPT_YEZIDI: `Yezi`, Since: 2.6.7
+ * @HB_SCRIPT_INVALID: No script set
  *
  * Data type for scripts. Each #hb_script_t's value is an #hb_tag_t corresponding
  * to the four-letter values defined by [ISO 15924](https://unicode.org/iso15924/).
@@ -441,208 +485,208 @@ hb_language_get_default (void);
  *
  **/
 
-/* https://unicode.org/iso15924/ */
 /* https://docs.google.com/spreadsheets/d/1Y90M0Ie3MUJ6UVCRDOypOtijlMDLNNyyLk36T6iMu0o */
-/* Unicode Character Database property: Script (sc) */
 typedef enum
 {
-  /*1.1*/ HB_SCRIPT_COMMON			= HB_TAG ('Z','y','y','y'),
-  /*1.1*/ HB_SCRIPT_INHERITED			= HB_TAG ('Z','i','n','h'),
-  /*5.0*/ HB_SCRIPT_UNKNOWN			= HB_TAG ('Z','z','z','z'),
-
-  /*1.1*/ HB_SCRIPT_ARABIC			= HB_TAG ('A','r','a','b'),
-  /*1.1*/ HB_SCRIPT_ARMENIAN			= HB_TAG ('A','r','m','n'),
-  /*1.1*/ HB_SCRIPT_BENGALI			= HB_TAG ('B','e','n','g'),
-  /*1.1*/ HB_SCRIPT_CYRILLIC			= HB_TAG ('C','y','r','l'),
-  /*1.1*/ HB_SCRIPT_DEVANAGARI			= HB_TAG ('D','e','v','a'),
-  /*1.1*/ HB_SCRIPT_GEORGIAN			= HB_TAG ('G','e','o','r'),
-  /*1.1*/ HB_SCRIPT_GREEK			= HB_TAG ('G','r','e','k'),
-  /*1.1*/ HB_SCRIPT_GUJARATI			= HB_TAG ('G','u','j','r'),
-  /*1.1*/ HB_SCRIPT_GURMUKHI			= HB_TAG ('G','u','r','u'),
-  /*1.1*/ HB_SCRIPT_HANGUL			= HB_TAG ('H','a','n','g'),
-  /*1.1*/ HB_SCRIPT_HAN				= HB_TAG ('H','a','n','i'),
-  /*1.1*/ HB_SCRIPT_HEBREW			= HB_TAG ('H','e','b','r'),
-  /*1.1*/ HB_SCRIPT_HIRAGANA			= HB_TAG ('H','i','r','a'),
-  /*1.1*/ HB_SCRIPT_KANNADA			= HB_TAG ('K','n','d','a'),
-  /*1.1*/ HB_SCRIPT_KATAKANA			= HB_TAG ('K','a','n','a'),
-  /*1.1*/ HB_SCRIPT_LAO				= HB_TAG ('L','a','o','o'),
-  /*1.1*/ HB_SCRIPT_LATIN			= HB_TAG ('L','a','t','n'),
-  /*1.1*/ HB_SCRIPT_MALAYALAM			= HB_TAG ('M','l','y','m'),
-  /*1.1*/ HB_SCRIPT_ORIYA			= HB_TAG ('O','r','y','a'),
-  /*1.1*/ HB_SCRIPT_TAMIL			= HB_TAG ('T','a','m','l'),
-  /*1.1*/ HB_SCRIPT_TELUGU			= HB_TAG ('T','e','l','u'),
-  /*1.1*/ HB_SCRIPT_THAI			= HB_TAG ('T','h','a','i'),
-
-  /*2.0*/ HB_SCRIPT_TIBETAN			= HB_TAG ('T','i','b','t'),
-
-  /*3.0*/ HB_SCRIPT_BOPOMOFO			= HB_TAG ('B','o','p','o'),
-  /*3.0*/ HB_SCRIPT_BRAILLE			= HB_TAG ('B','r','a','i'),
-  /*3.0*/ HB_SCRIPT_CANADIAN_SYLLABICS		= HB_TAG ('C','a','n','s'),
-  /*3.0*/ HB_SCRIPT_CHEROKEE			= HB_TAG ('C','h','e','r'),
-  /*3.0*/ HB_SCRIPT_ETHIOPIC			= HB_TAG ('E','t','h','i'),
-  /*3.0*/ HB_SCRIPT_KHMER			= HB_TAG ('K','h','m','r'),
-  /*3.0*/ HB_SCRIPT_MONGOLIAN			= HB_TAG ('M','o','n','g'),
-  /*3.0*/ HB_SCRIPT_MYANMAR			= HB_TAG ('M','y','m','r'),
-  /*3.0*/ HB_SCRIPT_OGHAM			= HB_TAG ('O','g','a','m'),
-  /*3.0*/ HB_SCRIPT_RUNIC			= HB_TAG ('R','u','n','r'),
-  /*3.0*/ HB_SCRIPT_SINHALA			= HB_TAG ('S','i','n','h'),
-  /*3.0*/ HB_SCRIPT_SYRIAC			= HB_TAG ('S','y','r','c'),
-  /*3.0*/ HB_SCRIPT_THAANA			= HB_TAG ('T','h','a','a'),
-  /*3.0*/ HB_SCRIPT_YI				= HB_TAG ('Y','i','i','i'),
-
-  /*3.1*/ HB_SCRIPT_DESERET			= HB_TAG ('D','s','r','t'),
-  /*3.1*/ HB_SCRIPT_GOTHIC			= HB_TAG ('G','o','t','h'),
-  /*3.1*/ HB_SCRIPT_OLD_ITALIC			= HB_TAG ('I','t','a','l'),
-
-  /*3.2*/ HB_SCRIPT_BUHID			= HB_TAG ('B','u','h','d'),
-  /*3.2*/ HB_SCRIPT_HANUNOO			= HB_TAG ('H','a','n','o'),
-  /*3.2*/ HB_SCRIPT_TAGALOG			= HB_TAG ('T','g','l','g'),
-  /*3.2*/ HB_SCRIPT_TAGBANWA			= HB_TAG ('T','a','g','b'),
-
-  /*4.0*/ HB_SCRIPT_CYPRIOT			= HB_TAG ('C','p','r','t'),
-  /*4.0*/ HB_SCRIPT_LIMBU			= HB_TAG ('L','i','m','b'),
-  /*4.0*/ HB_SCRIPT_LINEAR_B			= HB_TAG ('L','i','n','b'),
-  /*4.0*/ HB_SCRIPT_OSMANYA			= HB_TAG ('O','s','m','a'),
-  /*4.0*/ HB_SCRIPT_SHAVIAN			= HB_TAG ('S','h','a','w'),
-  /*4.0*/ HB_SCRIPT_TAI_LE			= HB_TAG ('T','a','l','e'),
-  /*4.0*/ HB_SCRIPT_UGARITIC			= HB_TAG ('U','g','a','r'),
-
-  /*4.1*/ HB_SCRIPT_BUGINESE			= HB_TAG ('B','u','g','i'),
-  /*4.1*/ HB_SCRIPT_COPTIC			= HB_TAG ('C','o','p','t'),
-  /*4.1*/ HB_SCRIPT_GLAGOLITIC			= HB_TAG ('G','l','a','g'),
-  /*4.1*/ HB_SCRIPT_KHAROSHTHI			= HB_TAG ('K','h','a','r'),
-  /*4.1*/ HB_SCRIPT_NEW_TAI_LUE			= HB_TAG ('T','a','l','u'),
-  /*4.1*/ HB_SCRIPT_OLD_PERSIAN			= HB_TAG ('X','p','e','o'),
-  /*4.1*/ HB_SCRIPT_SYLOTI_NAGRI		= HB_TAG ('S','y','l','o'),
-  /*4.1*/ HB_SCRIPT_TIFINAGH			= HB_TAG ('T','f','n','g'),
-
-  /*5.0*/ HB_SCRIPT_BALINESE			= HB_TAG ('B','a','l','i'),
-  /*5.0*/ HB_SCRIPT_CUNEIFORM			= HB_TAG ('X','s','u','x'),
-  /*5.0*/ HB_SCRIPT_NKO				= HB_TAG ('N','k','o','o'),
-  /*5.0*/ HB_SCRIPT_PHAGS_PA			= HB_TAG ('P','h','a','g'),
-  /*5.0*/ HB_SCRIPT_PHOENICIAN			= HB_TAG ('P','h','n','x'),
-
-  /*5.1*/ HB_SCRIPT_CARIAN			= HB_TAG ('C','a','r','i'),
-  /*5.1*/ HB_SCRIPT_CHAM			= HB_TAG ('C','h','a','m'),
-  /*5.1*/ HB_SCRIPT_KAYAH_LI			= HB_TAG ('K','a','l','i'),
-  /*5.1*/ HB_SCRIPT_LEPCHA			= HB_TAG ('L','e','p','c'),
-  /*5.1*/ HB_SCRIPT_LYCIAN			= HB_TAG ('L','y','c','i'),
-  /*5.1*/ HB_SCRIPT_LYDIAN			= HB_TAG ('L','y','d','i'),
-  /*5.1*/ HB_SCRIPT_OL_CHIKI			= HB_TAG ('O','l','c','k'),
-  /*5.1*/ HB_SCRIPT_REJANG			= HB_TAG ('R','j','n','g'),
-  /*5.1*/ HB_SCRIPT_SAURASHTRA			= HB_TAG ('S','a','u','r'),
-  /*5.1*/ HB_SCRIPT_SUNDANESE			= HB_TAG ('S','u','n','d'),
-  /*5.1*/ HB_SCRIPT_VAI				= HB_TAG ('V','a','i','i'),
-
-  /*5.2*/ HB_SCRIPT_AVESTAN			= HB_TAG ('A','v','s','t'),
-  /*5.2*/ HB_SCRIPT_BAMUM			= HB_TAG ('B','a','m','u'),
-  /*5.2*/ HB_SCRIPT_EGYPTIAN_HIEROGLYPHS	= HB_TAG ('E','g','y','p'),
-  /*5.2*/ HB_SCRIPT_IMPERIAL_ARAMAIC		= HB_TAG ('A','r','m','i'),
-  /*5.2*/ HB_SCRIPT_INSCRIPTIONAL_PAHLAVI	= HB_TAG ('P','h','l','i'),
-  /*5.2*/ HB_SCRIPT_INSCRIPTIONAL_PARTHIAN	= HB_TAG ('P','r','t','i'),
-  /*5.2*/ HB_SCRIPT_JAVANESE			= HB_TAG ('J','a','v','a'),
-  /*5.2*/ HB_SCRIPT_KAITHI			= HB_TAG ('K','t','h','i'),
-  /*5.2*/ HB_SCRIPT_LISU			= HB_TAG ('L','i','s','u'),
-  /*5.2*/ HB_SCRIPT_MEETEI_MAYEK		= HB_TAG ('M','t','e','i'),
-  /*5.2*/ HB_SCRIPT_OLD_SOUTH_ARABIAN		= HB_TAG ('S','a','r','b'),
-  /*5.2*/ HB_SCRIPT_OLD_TURKIC			= HB_TAG ('O','r','k','h'),
-  /*5.2*/ HB_SCRIPT_SAMARITAN			= HB_TAG ('S','a','m','r'),
-  /*5.2*/ HB_SCRIPT_TAI_THAM			= HB_TAG ('L','a','n','a'),
-  /*5.2*/ HB_SCRIPT_TAI_VIET			= HB_TAG ('T','a','v','t'),
-
-  /*6.0*/ HB_SCRIPT_BATAK			= HB_TAG ('B','a','t','k'),
-  /*6.0*/ HB_SCRIPT_BRAHMI			= HB_TAG ('B','r','a','h'),
-  /*6.0*/ HB_SCRIPT_MANDAIC			= HB_TAG ('M','a','n','d'),
-
-  /*6.1*/ HB_SCRIPT_CHAKMA			= HB_TAG ('C','a','k','m'),
-  /*6.1*/ HB_SCRIPT_MEROITIC_CURSIVE		= HB_TAG ('M','e','r','c'),
-  /*6.1*/ HB_SCRIPT_MEROITIC_HIEROGLYPHS	= HB_TAG ('M','e','r','o'),
-  /*6.1*/ HB_SCRIPT_MIAO			= HB_TAG ('P','l','r','d'),
-  /*6.1*/ HB_SCRIPT_SHARADA			= HB_TAG ('S','h','r','d'),
-  /*6.1*/ HB_SCRIPT_SORA_SOMPENG		= HB_TAG ('S','o','r','a'),
-  /*6.1*/ HB_SCRIPT_TAKRI			= HB_TAG ('T','a','k','r'),
+  HB_SCRIPT_COMMON			= HB_TAG ('Z','y','y','y'), /*1.1*/
+  HB_SCRIPT_INHERITED			= HB_TAG ('Z','i','n','h'), /*1.1*/
+  HB_SCRIPT_UNKNOWN			= HB_TAG ('Z','z','z','z'), /*5.0*/
+
+  HB_SCRIPT_ARABIC			= HB_TAG ('A','r','a','b'), /*1.1*/
+  HB_SCRIPT_ARMENIAN			= HB_TAG ('A','r','m','n'), /*1.1*/
+  HB_SCRIPT_BENGALI			= HB_TAG ('B','e','n','g'), /*1.1*/
+  HB_SCRIPT_CYRILLIC			= HB_TAG ('C','y','r','l'), /*1.1*/
+  HB_SCRIPT_DEVANAGARI			= HB_TAG ('D','e','v','a'), /*1.1*/
+  HB_SCRIPT_GEORGIAN			= HB_TAG ('G','e','o','r'), /*1.1*/
+  HB_SCRIPT_GREEK			= HB_TAG ('G','r','e','k'), /*1.1*/
+  HB_SCRIPT_GUJARATI			= HB_TAG ('G','u','j','r'), /*1.1*/
+  HB_SCRIPT_GURMUKHI			= HB_TAG ('G','u','r','u'), /*1.1*/
+  HB_SCRIPT_HANGUL			= HB_TAG ('H','a','n','g'), /*1.1*/
+  HB_SCRIPT_HAN				= HB_TAG ('H','a','n','i'), /*1.1*/
+  HB_SCRIPT_HEBREW			= HB_TAG ('H','e','b','r'), /*1.1*/
+  HB_SCRIPT_HIRAGANA			= HB_TAG ('H','i','r','a'), /*1.1*/
+  HB_SCRIPT_KANNADA			= HB_TAG ('K','n','d','a'), /*1.1*/
+  HB_SCRIPT_KATAKANA			= HB_TAG ('K','a','n','a'), /*1.1*/
+  HB_SCRIPT_LAO				= HB_TAG ('L','a','o','o'), /*1.1*/
+  HB_SCRIPT_LATIN			= HB_TAG ('L','a','t','n'), /*1.1*/
+  HB_SCRIPT_MALAYALAM			= HB_TAG ('M','l','y','m'), /*1.1*/
+  HB_SCRIPT_ORIYA			= HB_TAG ('O','r','y','a'), /*1.1*/
+  HB_SCRIPT_TAMIL			= HB_TAG ('T','a','m','l'), /*1.1*/
+  HB_SCRIPT_TELUGU			= HB_TAG ('T','e','l','u'), /*1.1*/
+  HB_SCRIPT_THAI			= HB_TAG ('T','h','a','i'), /*1.1*/
+
+  HB_SCRIPT_TIBETAN			= HB_TAG ('T','i','b','t'), /*2.0*/
+
+  HB_SCRIPT_BOPOMOFO			= HB_TAG ('B','o','p','o'), /*3.0*/
+  HB_SCRIPT_BRAILLE			= HB_TAG ('B','r','a','i'), /*3.0*/
+  HB_SCRIPT_CANADIAN_SYLLABICS		= HB_TAG ('C','a','n','s'), /*3.0*/
+  HB_SCRIPT_CHEROKEE			= HB_TAG ('C','h','e','r'), /*3.0*/
+  HB_SCRIPT_ETHIOPIC			= HB_TAG ('E','t','h','i'), /*3.0*/
+  HB_SCRIPT_KHMER			= HB_TAG ('K','h','m','r'), /*3.0*/
+  HB_SCRIPT_MONGOLIAN			= HB_TAG ('M','o','n','g'), /*3.0*/
+  HB_SCRIPT_MYANMAR			= HB_TAG ('M','y','m','r'), /*3.0*/
+  HB_SCRIPT_OGHAM			= HB_TAG ('O','g','a','m'), /*3.0*/
+  HB_SCRIPT_RUNIC			= HB_TAG ('R','u','n','r'), /*3.0*/
+  HB_SCRIPT_SINHALA			= HB_TAG ('S','i','n','h'), /*3.0*/
+  HB_SCRIPT_SYRIAC			= HB_TAG ('S','y','r','c'), /*3.0*/
+  HB_SCRIPT_THAANA			= HB_TAG ('T','h','a','a'), /*3.0*/
+  HB_SCRIPT_YI				= HB_TAG ('Y','i','i','i'), /*3.0*/
+
+  HB_SCRIPT_DESERET			= HB_TAG ('D','s','r','t'), /*3.1*/
+  HB_SCRIPT_GOTHIC			= HB_TAG ('G','o','t','h'), /*3.1*/
+  HB_SCRIPT_OLD_ITALIC			= HB_TAG ('I','t','a','l'), /*3.1*/
+
+  HB_SCRIPT_BUHID			= HB_TAG ('B','u','h','d'), /*3.2*/
+  HB_SCRIPT_HANUNOO			= HB_TAG ('H','a','n','o'), /*3.2*/
+  HB_SCRIPT_TAGALOG			= HB_TAG ('T','g','l','g'), /*3.2*/
+  HB_SCRIPT_TAGBANWA			= HB_TAG ('T','a','g','b'), /*3.2*/
+
+  HB_SCRIPT_CYPRIOT			= HB_TAG ('C','p','r','t'), /*4.0*/
+  HB_SCRIPT_LIMBU			= HB_TAG ('L','i','m','b'), /*4.0*/
+  HB_SCRIPT_LINEAR_B			= HB_TAG ('L','i','n','b'), /*4.0*/
+  HB_SCRIPT_OSMANYA			= HB_TAG ('O','s','m','a'), /*4.0*/
+  HB_SCRIPT_SHAVIAN			= HB_TAG ('S','h','a','w'), /*4.0*/
+  HB_SCRIPT_TAI_LE			= HB_TAG ('T','a','l','e'), /*4.0*/
+  HB_SCRIPT_UGARITIC			= HB_TAG ('U','g','a','r'), /*4.0*/
+
+  HB_SCRIPT_BUGINESE			= HB_TAG ('B','u','g','i'), /*4.1*/
+  HB_SCRIPT_COPTIC			= HB_TAG ('C','o','p','t'), /*4.1*/
+  HB_SCRIPT_GLAGOLITIC			= HB_TAG ('G','l','a','g'), /*4.1*/
+  HB_SCRIPT_KHAROSHTHI			= HB_TAG ('K','h','a','r'), /*4.1*/
+  HB_SCRIPT_NEW_TAI_LUE			= HB_TAG ('T','a','l','u'), /*4.1*/
+  HB_SCRIPT_OLD_PERSIAN			= HB_TAG ('X','p','e','o'), /*4.1*/
+  HB_SCRIPT_SYLOTI_NAGRI		= HB_TAG ('S','y','l','o'), /*4.1*/
+  HB_SCRIPT_TIFINAGH			= HB_TAG ('T','f','n','g'), /*4.1*/
+
+  HB_SCRIPT_BALINESE			= HB_TAG ('B','a','l','i'), /*5.0*/
+  HB_SCRIPT_CUNEIFORM			= HB_TAG ('X','s','u','x'), /*5.0*/
+  HB_SCRIPT_NKO				= HB_TAG ('N','k','o','o'), /*5.0*/
+  HB_SCRIPT_PHAGS_PA			= HB_TAG ('P','h','a','g'), /*5.0*/
+  HB_SCRIPT_PHOENICIAN			= HB_TAG ('P','h','n','x'), /*5.0*/
+
+  HB_SCRIPT_CARIAN			= HB_TAG ('C','a','r','i'), /*5.1*/
+  HB_SCRIPT_CHAM			= HB_TAG ('C','h','a','m'), /*5.1*/
+  HB_SCRIPT_KAYAH_LI			= HB_TAG ('K','a','l','i'), /*5.1*/
+  HB_SCRIPT_LEPCHA			= HB_TAG ('L','e','p','c'), /*5.1*/
+  HB_SCRIPT_LYCIAN			= HB_TAG ('L','y','c','i'), /*5.1*/
+  HB_SCRIPT_LYDIAN			= HB_TAG ('L','y','d','i'), /*5.1*/
+  HB_SCRIPT_OL_CHIKI			= HB_TAG ('O','l','c','k'), /*5.1*/
+  HB_SCRIPT_REJANG			= HB_TAG ('R','j','n','g'), /*5.1*/
+  HB_SCRIPT_SAURASHTRA			= HB_TAG ('S','a','u','r'), /*5.1*/
+  HB_SCRIPT_SUNDANESE			= HB_TAG ('S','u','n','d'), /*5.1*/
+  HB_SCRIPT_VAI				= HB_TAG ('V','a','i','i'), /*5.1*/
+
+  HB_SCRIPT_AVESTAN			= HB_TAG ('A','v','s','t'), /*5.2*/
+  HB_SCRIPT_BAMUM			= HB_TAG ('B','a','m','u'), /*5.2*/
+  HB_SCRIPT_EGYPTIAN_HIEROGLYPHS	= HB_TAG ('E','g','y','p'), /*5.2*/
+  HB_SCRIPT_IMPERIAL_ARAMAIC		= HB_TAG ('A','r','m','i'), /*5.2*/
+  HB_SCRIPT_INSCRIPTIONAL_PAHLAVI	= HB_TAG ('P','h','l','i'), /*5.2*/
+  HB_SCRIPT_INSCRIPTIONAL_PARTHIAN	= HB_TAG ('P','r','t','i'), /*5.2*/
+  HB_SCRIPT_JAVANESE			= HB_TAG ('J','a','v','a'), /*5.2*/
+  HB_SCRIPT_KAITHI			= HB_TAG ('K','t','h','i'), /*5.2*/
+  HB_SCRIPT_LISU			= HB_TAG ('L','i','s','u'), /*5.2*/
+  HB_SCRIPT_MEETEI_MAYEK		= HB_TAG ('M','t','e','i'), /*5.2*/
+  HB_SCRIPT_OLD_SOUTH_ARABIAN		= HB_TAG ('S','a','r','b'), /*5.2*/
+  HB_SCRIPT_OLD_TURKIC			= HB_TAG ('O','r','k','h'), /*5.2*/
+  HB_SCRIPT_SAMARITAN			= HB_TAG ('S','a','m','r'), /*5.2*/
+  HB_SCRIPT_TAI_THAM			= HB_TAG ('L','a','n','a'), /*5.2*/
+  HB_SCRIPT_TAI_VIET			= HB_TAG ('T','a','v','t'), /*5.2*/
+
+  HB_SCRIPT_BATAK			= HB_TAG ('B','a','t','k'), /*6.0*/
+  HB_SCRIPT_BRAHMI			= HB_TAG ('B','r','a','h'), /*6.0*/
+  HB_SCRIPT_MANDAIC			= HB_TAG ('M','a','n','d'), /*6.0*/
+
+  HB_SCRIPT_CHAKMA			= HB_TAG ('C','a','k','m'), /*6.1*/
+  HB_SCRIPT_MEROITIC_CURSIVE		= HB_TAG ('M','e','r','c'), /*6.1*/
+  HB_SCRIPT_MEROITIC_HIEROGLYPHS	= HB_TAG ('M','e','r','o'), /*6.1*/
+  HB_SCRIPT_MIAO			= HB_TAG ('P','l','r','d'), /*6.1*/
+  HB_SCRIPT_SHARADA			= HB_TAG ('S','h','r','d'), /*6.1*/
+  HB_SCRIPT_SORA_SOMPENG		= HB_TAG ('S','o','r','a'), /*6.1*/
+  HB_SCRIPT_TAKRI			= HB_TAG ('T','a','k','r'), /*6.1*/
 
   /*
    * Since: 0.9.30
    */
-  /*7.0*/ HB_SCRIPT_BASSA_VAH			= HB_TAG ('B','a','s','s'),
-  /*7.0*/ HB_SCRIPT_CAUCASIAN_ALBANIAN		= HB_TAG ('A','g','h','b'),
-  /*7.0*/ HB_SCRIPT_DUPLOYAN			= HB_TAG ('D','u','p','l'),
-  /*7.0*/ HB_SCRIPT_ELBASAN			= HB_TAG ('E','l','b','a'),
-  /*7.0*/ HB_SCRIPT_GRANTHA			= HB_TAG ('G','r','a','n'),
-  /*7.0*/ HB_SCRIPT_KHOJKI			= HB_TAG ('K','h','o','j'),
-  /*7.0*/ HB_SCRIPT_KHUDAWADI			= HB_TAG ('S','i','n','d'),
-  /*7.0*/ HB_SCRIPT_LINEAR_A			= HB_TAG ('L','i','n','a'),
-  /*7.0*/ HB_SCRIPT_MAHAJANI			= HB_TAG ('M','a','h','j'),
-  /*7.0*/ HB_SCRIPT_MANICHAEAN			= HB_TAG ('M','a','n','i'),
-  /*7.0*/ HB_SCRIPT_MENDE_KIKAKUI		= HB_TAG ('M','e','n','d'),
-  /*7.0*/ HB_SCRIPT_MODI			= HB_TAG ('M','o','d','i'),
-  /*7.0*/ HB_SCRIPT_MRO				= HB_TAG ('M','r','o','o'),
-  /*7.0*/ HB_SCRIPT_NABATAEAN			= HB_TAG ('N','b','a','t'),
-  /*7.0*/ HB_SCRIPT_OLD_NORTH_ARABIAN		= HB_TAG ('N','a','r','b'),
-  /*7.0*/ HB_SCRIPT_OLD_PERMIC			= HB_TAG ('P','e','r','m'),
-  /*7.0*/ HB_SCRIPT_PAHAWH_HMONG		= HB_TAG ('H','m','n','g'),
-  /*7.0*/ HB_SCRIPT_PALMYRENE			= HB_TAG ('P','a','l','m'),
-  /*7.0*/ HB_SCRIPT_PAU_CIN_HAU			= HB_TAG ('P','a','u','c'),
-  /*7.0*/ HB_SCRIPT_PSALTER_PAHLAVI		= HB_TAG ('P','h','l','p'),
-  /*7.0*/ HB_SCRIPT_SIDDHAM			= HB_TAG ('S','i','d','d'),
-  /*7.0*/ HB_SCRIPT_TIRHUTA			= HB_TAG ('T','i','r','h'),
-  /*7.0*/ HB_SCRIPT_WARANG_CITI			= HB_TAG ('W','a','r','a'),
-
-  /*8.0*/ HB_SCRIPT_AHOM			= HB_TAG ('A','h','o','m'),
-  /*8.0*/ HB_SCRIPT_ANATOLIAN_HIEROGLYPHS	= HB_TAG ('H','l','u','w'),
-  /*8.0*/ HB_SCRIPT_HATRAN			= HB_TAG ('H','a','t','r'),
-  /*8.0*/ HB_SCRIPT_MULTANI			= HB_TAG ('M','u','l','t'),
-  /*8.0*/ HB_SCRIPT_OLD_HUNGARIAN		= HB_TAG ('H','u','n','g'),
-  /*8.0*/ HB_SCRIPT_SIGNWRITING			= HB_TAG ('S','g','n','w'),
+  HB_SCRIPT_BASSA_VAH			= HB_TAG ('B','a','s','s'), /*7.0*/
+  HB_SCRIPT_CAUCASIAN_ALBANIAN		= HB_TAG ('A','g','h','b'), /*7.0*/
+  HB_SCRIPT_DUPLOYAN			= HB_TAG ('D','u','p','l'), /*7.0*/
+  HB_SCRIPT_ELBASAN			= HB_TAG ('E','l','b','a'), /*7.0*/
+  HB_SCRIPT_GRANTHA			= HB_TAG ('G','r','a','n'), /*7.0*/
+  HB_SCRIPT_KHOJKI			= HB_TAG ('K','h','o','j'), /*7.0*/
+  HB_SCRIPT_KHUDAWADI			= HB_TAG ('S','i','n','d'), /*7.0*/
+  HB_SCRIPT_LINEAR_A			= HB_TAG ('L','i','n','a'), /*7.0*/
+  HB_SCRIPT_MAHAJANI			= HB_TAG ('M','a','h','j'), /*7.0*/
+  HB_SCRIPT_MANICHAEAN			= HB_TAG ('M','a','n','i'), /*7.0*/
+  HB_SCRIPT_MENDE_KIKAKUI		= HB_TAG ('M','e','n','d'), /*7.0*/
+  HB_SCRIPT_MODI			= HB_TAG ('M','o','d','i'), /*7.0*/
+  HB_SCRIPT_MRO				= HB_TAG ('M','r','o','o'), /*7.0*/
+  HB_SCRIPT_NABATAEAN			= HB_TAG ('N','b','a','t'), /*7.0*/
+  HB_SCRIPT_OLD_NORTH_ARABIAN		= HB_TAG ('N','a','r','b'), /*7.0*/
+  HB_SCRIPT_OLD_PERMIC			= HB_TAG ('P','e','r','m'), /*7.0*/
+  HB_SCRIPT_PAHAWH_HMONG		= HB_TAG ('H','m','n','g'), /*7.0*/
+  HB_SCRIPT_PALMYRENE			= HB_TAG ('P','a','l','m'), /*7.0*/
+  HB_SCRIPT_PAU_CIN_HAU			= HB_TAG ('P','a','u','c'), /*7.0*/
+  HB_SCRIPT_PSALTER_PAHLAVI		= HB_TAG ('P','h','l','p'), /*7.0*/
+  HB_SCRIPT_SIDDHAM			= HB_TAG ('S','i','d','d'), /*7.0*/
+  HB_SCRIPT_TIRHUTA			= HB_TAG ('T','i','r','h'), /*7.0*/
+  HB_SCRIPT_WARANG_CITI			= HB_TAG ('W','a','r','a'), /*7.0*/
+
+  HB_SCRIPT_AHOM			= HB_TAG ('A','h','o','m'), /*8.0*/
+  HB_SCRIPT_ANATOLIAN_HIEROGLYPHS	= HB_TAG ('H','l','u','w'), /*8.0*/
+  HB_SCRIPT_HATRAN			= HB_TAG ('H','a','t','r'), /*8.0*/
+  HB_SCRIPT_MULTANI			= HB_TAG ('M','u','l','t'), /*8.0*/
+  HB_SCRIPT_OLD_HUNGARIAN		= HB_TAG ('H','u','n','g'), /*8.0*/
+  HB_SCRIPT_SIGNWRITING			= HB_TAG ('S','g','n','w'), /*8.0*/
 
   /*
    * Since 1.3.0
    */
-  /*9.0*/ HB_SCRIPT_ADLAM			= HB_TAG ('A','d','l','m'),
-  /*9.0*/ HB_SCRIPT_BHAIKSUKI			= HB_TAG ('B','h','k','s'),
-  /*9.0*/ HB_SCRIPT_MARCHEN			= HB_TAG ('M','a','r','c'),
-  /*9.0*/ HB_SCRIPT_OSAGE			= HB_TAG ('O','s','g','e'),
-  /*9.0*/ HB_SCRIPT_TANGUT			= HB_TAG ('T','a','n','g'),
-  /*9.0*/ HB_SCRIPT_NEWA			= HB_TAG ('N','e','w','a'),
+  HB_SCRIPT_ADLAM			= HB_TAG ('A','d','l','m'), /*9.0*/
+  HB_SCRIPT_BHAIKSUKI			= HB_TAG ('B','h','k','s'), /*9.0*/
+  HB_SCRIPT_MARCHEN			= HB_TAG ('M','a','r','c'), /*9.0*/
+  HB_SCRIPT_OSAGE			= HB_TAG ('O','s','g','e'), /*9.0*/
+  HB_SCRIPT_TANGUT			= HB_TAG ('T','a','n','g'), /*9.0*/
+  HB_SCRIPT_NEWA			= HB_TAG ('N','e','w','a'), /*9.0*/
 
   /*
    * Since 1.6.0
    */
-  /*10.0*/HB_SCRIPT_MASARAM_GONDI		= HB_TAG ('G','o','n','m'),
-  /*10.0*/HB_SCRIPT_NUSHU			= HB_TAG ('N','s','h','u'),
-  /*10.0*/HB_SCRIPT_SOYOMBO			= HB_TAG ('S','o','y','o'),
-  /*10.0*/HB_SCRIPT_ZANABAZAR_SQUARE		= HB_TAG ('Z','a','n','b'),
+  HB_SCRIPT_MASARAM_GONDI		= HB_TAG ('G','o','n','m'), /*10.0*/
+  HB_SCRIPT_NUSHU			= HB_TAG ('N','s','h','u'), /*10.0*/
+  HB_SCRIPT_SOYOMBO			= HB_TAG ('S','o','y','o'), /*10.0*/
+  HB_SCRIPT_ZANABAZAR_SQUARE		= HB_TAG ('Z','a','n','b'), /*10.0*/
 
   /*
    * Since 1.8.0
    */
-  /*11.0*/HB_SCRIPT_DOGRA			= HB_TAG ('D','o','g','r'),
-  /*11.0*/HB_SCRIPT_GUNJALA_GONDI		= HB_TAG ('G','o','n','g'),
-  /*11.0*/HB_SCRIPT_HANIFI_ROHINGYA		= HB_TAG ('R','o','h','g'),
-  /*11.0*/HB_SCRIPT_MAKASAR			= HB_TAG ('M','a','k','a'),
-  /*11.0*/HB_SCRIPT_MEDEFAIDRIN			= HB_TAG ('M','e','d','f'),
-  /*11.0*/HB_SCRIPT_OLD_SOGDIAN			= HB_TAG ('S','o','g','o'),
-  /*11.0*/HB_SCRIPT_SOGDIAN			= HB_TAG ('S','o','g','d'),
+  HB_SCRIPT_DOGRA			= HB_TAG ('D','o','g','r'), /*11.0*/
+  HB_SCRIPT_GUNJALA_GONDI		= HB_TAG ('G','o','n','g'), /*11.0*/
+  HB_SCRIPT_HANIFI_ROHINGYA		= HB_TAG ('R','o','h','g'), /*11.0*/
+  HB_SCRIPT_MAKASAR			= HB_TAG ('M','a','k','a'), /*11.0*/
+  HB_SCRIPT_MEDEFAIDRIN			= HB_TAG ('M','e','d','f'), /*11.0*/
+  HB_SCRIPT_OLD_SOGDIAN			= HB_TAG ('S','o','g','o'), /*11.0*/
+  HB_SCRIPT_SOGDIAN			= HB_TAG ('S','o','g','d'), /*11.0*/
 
   /*
    * Since 2.4.0
    */
-  /*12.0*/HB_SCRIPT_ELYMAIC			= HB_TAG ('E','l','y','m'),
-  /*12.0*/HB_SCRIPT_NANDINAGARI			= HB_TAG ('N','a','n','d'),
-  /*12.0*/HB_SCRIPT_NYIAKENG_PUACHUE_HMONG	= HB_TAG ('H','m','n','p'),
-  /*12.0*/HB_SCRIPT_WANCHO			= HB_TAG ('W','c','h','o'),
+  HB_SCRIPT_ELYMAIC			= HB_TAG ('E','l','y','m'), /*12.0*/
+  HB_SCRIPT_NANDINAGARI			= HB_TAG ('N','a','n','d'), /*12.0*/
+  HB_SCRIPT_NYIAKENG_PUACHUE_HMONG	= HB_TAG ('H','m','n','p'), /*12.0*/
+  HB_SCRIPT_WANCHO			= HB_TAG ('W','c','h','o'), /*12.0*/
 
   /*
    * Since 2.6.7
    */
-  /*13.0*/HB_SCRIPT_CHORASMIAN			= HB_TAG ('C','h','r','s'),
-  /*13.0*/HB_SCRIPT_DIVES_AKURU			= HB_TAG ('D','i','a','k'),
-  /*13.0*/HB_SCRIPT_KHITAN_SMALL_SCRIPT		= HB_TAG ('K','i','t','s'),
-  /*13.0*/HB_SCRIPT_YEZIDI			= HB_TAG ('Y','e','z','i'),
+  HB_SCRIPT_CHORASMIAN			= HB_TAG ('C','h','r','s'), /*13.0*/
+  HB_SCRIPT_DIVES_AKURU			= HB_TAG ('D','i','a','k'), /*13.0*/
+  HB_SCRIPT_KHITAN_SMALL_SCRIPT		= HB_TAG ('K','i','t','s'), /*13.0*/
+  HB_SCRIPT_YEZIDI			= HB_TAG ('Y','e','z','i'), /*13.0*/
 
   /* No script set. */
-  HB_SCRIPT_INVALID				= HB_TAG_NONE,
+  HB_SCRIPT_INVALID			= HB_TAG_NONE,
+
+  /*< private >*/
 
   /* Dummy values to ensure any hb_tag_t value can be passed/stored as hb_script_t
    * without risking undefined behavior.  We have two, for historical reasons.
@@ -687,19 +731,33 @@ typedef struct hb_user_data_key_t {
   char unused;
 } hb_user_data_key_t;
 
+/**
+ * hb_destroy_func_t:
+ * @user_data: the data to be destroyed
+ *
+ * A virtual method for destroy user-data callbacks.
+ *
+ */
 typedef void (*hb_destroy_func_t) (void *user_data);
 
 
 /* Font features and variations. */
 
 /**
- * HB_FEATURE_GLOBAL_START
+ * HB_FEATURE_GLOBAL_START:
+ *
+ * Special setting for #hb_feature_t.start to apply the feature from the start
+ * of the buffer.
  *
  * Since: 2.0.0
  */
 #define HB_FEATURE_GLOBAL_START	0
+
 /**
- * HB_FEATURE_GLOBAL_END
+ * HB_FEATURE_GLOBAL_END:
+ *
+ * Special setting for #hb_feature_t.end to apply the feature from to the end
+ * of the buffer.
  *
  * Since: 2.0.0
  */
@@ -717,7 +775,7 @@ typedef void (*hb_destroy_func_t) (void *user_data);
  * The #hb_feature_t is the structure that holds information about requested
  * feature application. The feature will be applied with the given value to all
  * glyphs which are in clusters between @start (inclusive) and @end (exclusive).
- * Setting start to @HB_FEATURE_GLOBAL_START and end to @HB_FEATURE_GLOBAL_END
+ * Setting start to #HB_FEATURE_GLOBAL_START and end to #HB_FEATURE_GLOBAL_END
  * specifies that the feature always applies to the entire buffer.
  */
 typedef struct hb_feature_t {
@@ -741,8 +799,8 @@ hb_feature_to_string (hb_feature_t *feature,
  * @value: The value of the variation axis
  *
  * Data type for holding variation data. Registered OpenType
- * variation-axis tags are listed at
- * https://docs.microsoft.com/en-us/typography/opentype/spec/dvaraxisreg
+ * variation-axis tags are listed in
+ * [OpenType Axis Tag Registry](https://docs.microsoft.com/en-us/typography/opentype/spec/dvaraxisreg).
  * 
  * Since: 1.4.2
  */
@@ -769,6 +827,17 @@ hb_variation_to_string (hb_variation_t *variation,
  */
 typedef uint32_t hb_color_t;
 
+/**
+ * HB_COLOR:
+ * @b: blue channel value
+ * @g: green channel value
+ * @r: red channel value
+ * @a: alpha channel value
+ *
+ * Constructs an #hb_color_t from four integers.
+ *
+ * Since: 2.1.0
+ */
 #define HB_COLOR(b,g,r,a) ((hb_color_t) HB_TAG ((b),(g),(r),(a)))
 
 HB_EXTERN uint8_t
diff --git a/thirdparty/harfbuzz/src/hb-coretext.cc b/thirdparty/harfbuzz/src/hb-coretext.cc
index 7b6b2bd5ef..461bd20e65 100644
--- a/thirdparty/harfbuzz/src/hb-coretext.cc
+++ b/thirdparty/harfbuzz/src/hb-coretext.cc
@@ -34,7 +34,6 @@
 
 #include "hb-coretext.h"
 #include "hb-aat-layout.hh"
-#include <math.h>
 
 
 /**
@@ -190,7 +189,10 @@ create_ct_font (CGFontRef cg_font, CGFloat font_size)
    * reconfiguring the cascade list causes CoreText crashes. For details, see
    * crbug.com/549610 */
   // 0x00070000 stands for "kCTVersionNumber10_10", see CoreText.h
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   if (&CTGetCoreTextVersion != nullptr && CTGetCoreTextVersion() < 0x00070000) {
+#pragma GCC diagnostic pop
     CFStringRef fontName = CTFontCopyPostScriptName (ct_font);
     bool isEmojiFont = CFStringCompare (fontName, CFSTR("AppleColorEmoji"), 0) == kCFCompareEqualTo;
     CFRelease (fontName);
@@ -346,7 +348,7 @@ retry:
   const hb_coretext_font_data_t *data = font->data.coretext;
   if (unlikely (!data)) return nullptr;
 
-  if (fabs (CTFontGetSize ((CTFontRef) data) - (CGFloat) font->ptem) > .5)
+  if (fabs (CTFontGetSize ((CTFontRef) data) - (CGFloat) font->ptem) > (CGFloat) .5)
   {
     /* XXX-MT-bug
      * Note that evaluating condition above can be dangerous if another thread
@@ -402,7 +404,7 @@ hb_coretext_font_create (CTFontRef ct_font)
 }
 
 /**
- * hb_coretext_face_get_ct_font:
+ * hb_coretext_font_get_ct_font:
  * @font: #hb_font_t to work upon
  *
  * Fetches the CTFontRef associated with the specified
@@ -858,7 +860,7 @@ resize_and_retry:
 
     buffer->len = 0;
     uint32_t status_and = ~0, status_or = 0;
-    double advances_so_far = 0;
+    CGFloat advances_so_far = 0;
     /* For right-to-left runs, CoreText returns the glyphs positioned such that
      * any trailing whitespace is to the left of (0,0).  Adjust coordinate system
      * to fix for that.  Test with any RTL string with trailing spaces.
@@ -880,10 +882,10 @@ resize_and_retry:
       status_or  |= run_status;
       status_and &= run_status;
       DEBUG_MSG (CORETEXT, run, "CTRunStatus: %x", run_status);
-      double run_advance = CTRunGetTypographicBounds (run, range_all, nullptr, nullptr, nullptr);
+      CGFloat run_advance = CTRunGetTypographicBounds (run, range_all, nullptr, nullptr, nullptr);
       if (HB_DIRECTION_IS_VERTICAL (buffer->props.direction))
 	  run_advance = -run_advance;
-      DEBUG_MSG (CORETEXT, run, "Run advance: %g", run_advance);
+      DEBUG_MSG (CORETEXT, run, "Run advance: %g", (double) run_advance);
 
       /* CoreText does automatic font fallback (AKA "cascading") for  characters
        * not supported by the requested font, and provides no way to turn it off,
@@ -1062,7 +1064,7 @@ resize_and_retry:
 	  hb_position_t x_offset = (positions[0].x - advances_so_far) * x_mult;
 	  for (unsigned int j = 0; j < num_glyphs; j++)
 	  {
-	    double advance;
+	    CGFloat advance;
 	    if (likely (j + 1 < num_glyphs))
 	      advance = positions[j + 1].x - positions[j].x;
 	    else /* last glyph */
@@ -1078,7 +1080,7 @@ resize_and_retry:
 	  hb_position_t y_offset = (positions[0].y - advances_so_far) * y_mult;
 	  for (unsigned int j = 0; j < num_glyphs; j++)
 	  {
-	    double advance;
+	    CGFloat advance;
 	    if (likely (j + 1 < num_glyphs))
 	      advance = positions[j + 1].y - positions[j].y;
 	    else /* last glyph */
diff --git a/thirdparty/harfbuzz/src/hb-deprecated.h b/thirdparty/harfbuzz/src/hb-deprecated.h
index 43f89a4c4e..5f19125789 100644
--- a/thirdparty/harfbuzz/src/hb-deprecated.h
+++ b/thirdparty/harfbuzz/src/hb-deprecated.h
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -53,11 +53,50 @@ HB_BEGIN_DECLS
 #ifndef HB_DISABLE_DEPRECATED
 
 
+/**
+ * HB_SCRIPT_CANADIAN_ABORIGINAL:
+ *
+ * Use #HB_SCRIPT_CANADIAN_SYLLABICS instead:
+ *
+ * Deprecated: 0.9.20
+ */
 #define HB_SCRIPT_CANADIAN_ABORIGINAL		HB_SCRIPT_CANADIAN_SYLLABICS
 
+/**
+ * HB_BUFFER_FLAGS_DEFAULT:
+ *
+ * Use #HB_BUFFER_FLAG_DEFAULT instead.
+ *
+ * Deprecated: 0.9.20
+ */
 #define HB_BUFFER_FLAGS_DEFAULT			HB_BUFFER_FLAG_DEFAULT
+/**
+ * HB_BUFFER_SERIALIZE_FLAGS_DEFAULT:
+ *
+ * Use #HB_BUFFER_SERIALIZE_FLAG_DEFAULT instead.
+ *
+ * Deprecated: 0.9.20
+ */
 #define HB_BUFFER_SERIALIZE_FLAGS_DEFAULT	HB_BUFFER_SERIALIZE_FLAG_DEFAULT
 
+/**
+ * hb_font_get_glyph_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @unicode: The Unicode code point to query
+ * @variation_selector: The  variation-selector code point to query
+ * @glyph: (out): The glyph ID retrieved
+ * @user_data: User data pointer passed by the caller
+ *
+ * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
+ *
+ * This method should retrieve the glyph ID for a specified Unicode code point
+ * font, with an optional variation selector.
+ *
+ * Return value: %true if data found, %false otherwise
+ * Deprecated: 1.2.3
+ *
+ **/
 typedef hb_bool_t (*hb_font_get_glyph_func_t) (hb_font_t *font, void *font_data,
 					       hb_codepoint_t unicode, hb_codepoint_t variation_selector,
 					       hb_codepoint_t *glyph,
@@ -73,6 +112,11 @@ hb_set_invert (hb_set_t *set);
 
 /**
  * hb_unicode_eastasian_width_func_t:
+ * @ufuncs: A Unicode-functions structure
+ * @unicode: The code point to query
+ * @user_data: User data pointer passed by the caller
+ *
+ * A virtual method for the #hb_unicode_funcs_t structure.
  *
  * Deprecated: 2.0.0
  */
@@ -82,12 +126,12 @@ typedef unsigned int			(*hb_unicode_eastasian_width_func_t)	(hb_unicode_funcs_t
 
 /**
  * hb_unicode_funcs_set_eastasian_width_func:
- * @ufuncs: a Unicode function structure
- * @func: (closure user_data) (destroy destroy) (scope notified):
- * @user_data:
- * @destroy:
+ * @ufuncs: a Unicode-function structure
+ * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
+ * @user_data: Data to pass to @func
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
- * 
+ * Sets the implementation function for #hb_unicode_eastasian_width_func_t.
  *
  * Since: 0.9.2
  * Deprecated: 2.0.0
@@ -99,6 +143,10 @@ hb_unicode_funcs_set_eastasian_width_func (hb_unicode_funcs_t *ufuncs,
 
 /**
  * hb_unicode_eastasian_width:
+ * @ufuncs: a Unicode-function structure
+ * @unicode: The code point to query
+ *
+ * Don't use. Not used by HarfBuzz.
  *
  * Since: 0.9.2
  * Deprecated: 2.0.0
@@ -112,7 +160,7 @@ hb_unicode_eastasian_width (hb_unicode_funcs_t *ufuncs,
  * hb_unicode_decompose_compatibility_func_t:
  * @ufuncs: a Unicode function structure
  * @u: codepoint to decompose
- * @decomposed: address of codepoint array (of length %HB_UNICODE_MAX_DECOMPOSITION_LEN) to write decomposition into
+ * @decomposed: address of codepoint array (of length #HB_UNICODE_MAX_DECOMPOSITION_LEN) to write decomposition into
  * @user_data: user data pointer as passed to hb_unicode_funcs_set_decompose_compatibility_func()
  *
  * Fully decompose @u to its Unicode compatibility decomposition. The codepoints of the decomposition will be written to @decomposed.
@@ -120,7 +168,7 @@ hb_unicode_eastasian_width (hb_unicode_funcs_t *ufuncs,
  *
  * If @u has no compatibility decomposition, zero should be returned.
  *
- * The Unicode standard guarantees that a buffer of length %HB_UNICODE_MAX_DECOMPOSITION_LEN codepoints will always be sufficient for any
+ * The Unicode standard guarantees that a buffer of length #HB_UNICODE_MAX_DECOMPOSITION_LEN codepoints will always be sufficient for any
  * compatibility decomposition plus an terminating value of 0.  Consequently, @decompose must be allocated by the caller to be at least this length.  Implementations
  * of this function type must ensure that they do not write past the provided array.
  *
@@ -144,10 +192,12 @@ typedef unsigned int			(*hb_unicode_decompose_compatibility_func_t)	(hb_unicode_
 
 /**
  * hb_unicode_funcs_set_decompose_compatibility_func:
- * @ufuncs: a Unicode function structure
- * @func: (closure user_data) (destroy destroy) (scope notified):
- * @user_data:
- * @destroy:
+ * @ufuncs: A Unicode-functions structure
+ * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
+ * @user_data: Data to pass to @func
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
+ *
+ * Sets the implementation function for #hb_unicode_decompose_compatibility_func_t.
  *
  * 
  *
@@ -165,16 +215,25 @@ hb_unicode_decompose_compatibility (hb_unicode_funcs_t *ufuncs,
 				    hb_codepoint_t     *decomposed);
 
 
+/**
+ * hb_font_get_glyph_v_kerning_func_t:
+ *
+ * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
+ *
+ * This method should retrieve the kerning-adjustment value for a glyph-pair in
+ * the specified font, for vertical text segments.
+ *
+ **/
 typedef hb_font_get_glyph_kerning_func_t hb_font_get_glyph_v_kerning_func_t;
 
 /**
  * hb_font_funcs_set_glyph_v_kerning_func:
- * @ffuncs: font functions.
- * @func: (closure user_data) (destroy destroy) (scope notified):
- * @user_data:
- * @destroy:
+ * @ffuncs: A font-function structure
+ * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
+ * @user_data: Data to pass to @func
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
- * 
+ * Sets the implementation function for #hb_font_get_glyph_v_kerning_func_t.
  *
  * Since: 0.9.2
  * Deprecated: 2.0.0
diff --git a/thirdparty/harfbuzz/src/hb-directwrite.cc b/thirdparty/harfbuzz/src/hb-directwrite.cc
index 92c956c032..a07302159c 100644
--- a/thirdparty/harfbuzz/src/hb-directwrite.cc
+++ b/thirdparty/harfbuzz/src/hb-directwrite.cc
@@ -957,6 +957,8 @@ _hb_directwrite_font_release (void *data)
  * hb_directwrite_face_create:
  * @font_face: a DirectWrite IDWriteFontFace object.
  *
+ * Constructs a new face object from the specified DirectWrite IDWriteFontFace.
+ *
  * Return value: #hb_face_t object corresponding to the given input
  *
  * Since: 2.4.0
@@ -974,6 +976,8 @@ hb_directwrite_face_create (IDWriteFontFace *font_face)
 * hb_directwrite_face_get_font_face:
 * @face: a #hb_face_t object
 *
+* Gets the DirectWrite IDWriteFontFace associated with @face.
+*
 * Return value: DirectWrite IDWriteFontFace object corresponding to the given input
 *
 * Since: 2.5.0
diff --git a/thirdparty/harfbuzz/src/hb-dispatch.hh b/thirdparty/harfbuzz/src/hb-dispatch.hh
index 7eace86e54..4b2b65a8de 100644
--- a/thirdparty/harfbuzz/src/hb-dispatch.hh
+++ b/thirdparty/harfbuzz/src/hb-dispatch.hh
@@ -38,7 +38,6 @@
 template <typename Context, typename Return=hb_empty_t, unsigned int MaxDebugDepth=0>
 struct hb_dispatch_context_t
 {
-  hb_dispatch_context_t () : debug_depth (0) {}
   private:
   /* https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern */
   const Context* thiz () const { return static_cast<const Context *> (this); }
@@ -54,7 +53,7 @@ struct hb_dispatch_context_t
   { return obj.dispatch (thiz (), hb_forward<Ts> (ds)...); }
   static return_t no_dispatch_return_value () { return Context::default_return_value (); }
   static bool stop_sublookup_iteration (const return_t r HB_UNUSED) { return false; }
-  unsigned debug_depth;
+  unsigned debug_depth = 0;
 };
 
 
diff --git a/thirdparty/harfbuzz/src/hb-draw.h b/thirdparty/harfbuzz/src/hb-draw.h
index 98eccf4c0c..bddc876399 100644
--- a/thirdparty/harfbuzz/src/hb-draw.h
+++ b/thirdparty/harfbuzz/src/hb-draw.h
@@ -22,7 +22,7 @@
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
diff --git a/thirdparty/harfbuzz/src/hb-face.cc b/thirdparty/harfbuzz/src/hb-face.cc
index 33a788e7c5..61bd4af7b1 100644
--- a/thirdparty/harfbuzz/src/hb-face.cc
+++ b/thirdparty/harfbuzz/src/hb-face.cc
@@ -89,8 +89,8 @@ DEFINE_NULL_INSTANCE (hb_face_t) =
   nullptr, /* destroy */
 
   0,    /* index */
-  HB_ATOMIC_INT_INIT (1000), /* upem */
-  HB_ATOMIC_INT_INIT (0),    /* num_glyphs */
+  1000, /* upem */
+  0,    /* num_glyphs */
 
   /* Zero for the rest is fine. */
 };
@@ -100,7 +100,7 @@ DEFINE_NULL_INSTANCE (hb_face_t) =
  * hb_face_create_for_tables:
  * @reference_table_func: (closure user_data) (destroy destroy) (scope notified): Table-referencing function
  * @user_data: A pointer to the user data
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  *
  * Variant of hb_face_create(), built for those cases where it is more
  * convenient to provide data for individual tables instead of the whole font
@@ -235,7 +235,7 @@ hb_face_create (hb_blob_t    *blob,
  *
  * Fetches the singleton empty face object.
  *
- * Return value: (transfer full) The empty face object
+ * Return value: (transfer full): The empty face object
  *
  * Since: 0.9.2
  **/
@@ -299,7 +299,7 @@ hb_face_destroy (hb_face_t *face)
  * @face: A face object
  * @key: The user-data key to set
  * @data: A pointer to the user data
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the given face object. 
@@ -360,7 +360,7 @@ hb_face_make_immutable (hb_face_t *face)
  *
  * Tests whether the given face object is immutable.
  *
- * Return value: True is @face is immutable, false otherwise
+ * Return value: %true is @face is immutable, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -756,7 +756,7 @@ hb_face_builder_add_table (hb_face_t *face, hb_tag_t tag, hb_blob_t *blob)
   hb_face_builder_data_t *data = (hb_face_builder_data_t *) face->user_data;
 
   hb_face_builder_data_t::table_entry_t *entry = data->tables.push ();
-  if (data->tables.in_error())
+  if (unlikely (data->tables.in_error()))
     return false;
 
   entry->tag = tag;
diff --git a/thirdparty/harfbuzz/src/hb-face.h b/thirdparty/harfbuzz/src/hb-face.h
index 3b18f7eef9..6ef2f8b886 100644
--- a/thirdparty/harfbuzz/src/hb-face.h
+++ b/thirdparty/harfbuzz/src/hb-face.h
@@ -24,7 +24,7 @@
  * Red Hat Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -58,6 +58,19 @@ HB_EXTERN hb_face_t *
 hb_face_create (hb_blob_t    *blob,
 		unsigned int  index);
 
+/**
+ * hb_reference_table_func_t:
+ * @face: an #hb_face_t to reference table for
+ * @tag: the tag of the table to reference
+ * @user_data: User data pointer passed by the caller
+ *
+ * Callback function for hb_face_create_for_tables().
+ *
+ * Return value: (transfer full): A pointer to the @tag table within @face
+ *
+ * Since: 0.9.2
+ */
+
 typedef hb_blob_t * (*hb_reference_table_func_t)  (hb_face_t *face, hb_tag_t tag, void *user_data);
 
 /* calls destroy() when not needing user_data anymore */
diff --git a/thirdparty/harfbuzz/src/hb-face.hh b/thirdparty/harfbuzz/src/hb-face.hh
index f1b472ccf3..765f272858 100644
--- a/thirdparty/harfbuzz/src/hb-face.hh
+++ b/thirdparty/harfbuzz/src/hb-face.hh
@@ -81,7 +81,7 @@ struct hb_face_t
     return blob;
   }
 
-  HB_PURE_FUNC unsigned int get_upem () const
+  unsigned int get_upem () const
   {
     unsigned int ret = upem.get_relaxed ();
     if (unlikely (!ret))
diff --git a/thirdparty/harfbuzz/src/hb-font.cc b/thirdparty/harfbuzz/src/hb-font.cc
index 5c8357ff28..37a0e7fe85 100644
--- a/thirdparty/harfbuzz/src/hb-font.cc
+++ b/thirdparty/harfbuzz/src/hb-font.cc
@@ -628,7 +628,7 @@ hb_font_funcs_destroy (hb_font_funcs_t *ffuncs)
  * @ffuncs: The font-functions structure
  * @key: The user-data key to set
  * @data: A pointer to the user data set
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the specified font-functions structure. 
@@ -690,7 +690,7 @@ hb_font_funcs_make_immutable (hb_font_funcs_t *ffuncs)
  *
  * Tests whether a font-functions structure is immutable.
  *
- * Return value: %true if @ffuncs is immutable, false otherwise
+ * Return value: %true if @ffuncs is immutable, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -753,10 +753,10 @@ hb_font_t::has_func (unsigned int i)
  * @font: #hb_font_t to work upon
  * @extents: (out): The font extents retrieved
  *
- * Fetches the extents for a specified font, in horizontal
+ * Fetches the extents for a specified font, for horizontal
  * text segments.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 1.1.3
  **/
@@ -772,10 +772,10 @@ hb_font_get_h_extents (hb_font_t         *font,
  * @font: #hb_font_t to work upon
  * @extents: (out): The font extents retrieved
  *
- * Fetches the extents for a specified font, in vertical
+ * Fetches the extents for a specified font, for vertical
  * text segments.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 1.1.3
  **/
@@ -790,7 +790,7 @@ hb_font_get_v_extents (hb_font_t         *font,
  * hb_font_get_glyph:
  * @font: #hb_font_t to work upon
  * @unicode: The Unicode code point to query
- * @variation_selector: (optional): A variation-selector code point
+ * @variation_selector: A variation-selector code point
  * @glyph: (out): The glyph ID retrieved
  *
  * Fetches the glyph ID for a Unicode code point in the specified
@@ -799,7 +799,7 @@ hb_font_get_v_extents (hb_font_t         *font,
  * If @variation_selector is 0, calls hb_font_get_nominal_glyph();
  * otherwise calls hb_font_get_variation_glyph().
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -827,7 +827,7 @@ hb_font_get_glyph (hb_font_t      *font,
  * for code points modified by variation selectors. For variation-selector
  * support, user hb_font_get_variation_glyph() or use hb_font_get_glyph().
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 1.2.3
  **/
@@ -841,11 +841,17 @@ hb_font_get_nominal_glyph (hb_font_t      *font,
 
 /**
  * hb_font_get_nominal_glyphs:
- * @font: a font.
- *
+ * @font: #hb_font_t to work upon
+ * @count: number of code points to query
+ * @first_unicode: The first Unicode code point to query
+ * @unicode_stride: The stride between successive code points
+ * @first_glyph: (out): The first glyph ID retrieved
+ * @glyph_stride: The stride between successive glyph IDs
  *
+ * Fetches the nominal glyph IDs for a sequence of Unicode code points. Glyph
+ * IDs must be returned in a #hb_codepoint_t output parameter.
  *
- * Return value:
+ * Return value: the number of code points processed
  *
  * Since: 2.6.3
  **/
@@ -873,7 +879,7 @@ hb_font_get_nominal_glyphs (hb_font_t *font,
  * by the specified variation-selector code point, in the specified
  * font.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 1.2.3
  **/
@@ -931,7 +937,7 @@ hb_font_get_glyph_v_advance (hb_font_t      *font,
  * @first_glyph: The first glyph ID to query
  * @glyph_stride: The stride between successive glyph IDs
  * @first_advance: (out): The first advance retrieved
- * @advance_stride: (out): The stride between successive advances
+ * @advance_stride: The stride between successive advances
  *
  * Fetches the advances for a sequence of glyph IDs in the specified
  * font, for horizontal text segments. 
@@ -983,7 +989,7 @@ hb_font_get_glyph_v_advances (hb_font_t*            font,
  * Fetches the (X,Y) coordinates of the origin for a glyph ID
  * in the specified font, for horizontal text segments.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1006,7 +1012,7 @@ hb_font_get_glyph_h_origin (hb_font_t      *font,
  * Fetches the (X,Y) coordinates of the origin for a glyph ID
  * in the specified font, for vertical text segments.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1026,7 +1032,7 @@ hb_font_get_glyph_v_origin (hb_font_t      *font,
  * @right_glyph: The glyph ID of the right glyph in the glyph pair
  *
  * Fetches the kerning-adjustment value for a glyph-pair in
- * the specified font, in horizontal text segments.
+ * the specified font, for horizontal text segments.
  *
  * <note>It handles legacy kerning only (as returned by the corresponding
  * #hb_font_funcs_t function).</note>
@@ -1051,7 +1057,7 @@ hb_font_get_glyph_h_kerning (hb_font_t      *font,
  * @bottom_glyph: The glyph ID of the bottom glyph in the glyph pair
  *
  * Fetches the kerning-adjustment value for a glyph-pair in
- * the specified font, in vertical text segments.
+ * the specified font, for vertical text segments.
  *
  * <note>It handles legacy kerning only (as returned by the corresponding
  * #hb_font_funcs_t function).</note>
@@ -1079,7 +1085,7 @@ hb_font_get_glyph_v_kerning (hb_font_t      *font,
  * Fetches the #hb_glyph_extents_t data for a glyph ID
  * in the specified font.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1102,7 +1108,7 @@ hb_font_get_glyph_extents (hb_font_t          *font,
  * Fetches the (x,y) coordinates of a specified contour-point index
  * in the specified glyph, within the specified font.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1125,7 +1131,7 @@ hb_font_get_glyph_contour_point (hb_font_t      *font,
  *
  * Fetches the glyph-name string for a glyph ID in the specified @font.
  *
- * Return value: %true if data found, zero otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1149,7 +1155,7 @@ hb_font_get_glyph_name (hb_font_t      *font,
  *
  * <note>Note: @len == -1 means the name string is null-terminated.</note>
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1169,7 +1175,7 @@ hb_font_get_glyph_from_name (hb_font_t      *font,
  * hb_font_get_extents_for_direction:
  * @font: #hb_font_t to work upon
  * @direction: The direction of the text segment
- * @extents: (out): The #hb_glyph_extents_t retrieved
+ * @extents: (out): The #hb_font_extents_t retrieved
  *
  * Fetches the extents for a font in a text segment of the
  * specified direction.
@@ -1364,7 +1370,7 @@ hb_font_get_glyph_kerning_for_direction (hb_font_t      *font,
  * Calls the appropriate direction-specific variant (horizontal
  * or vertical) depending on the value of @direction.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1393,7 +1399,7 @@ hb_font_get_glyph_extents_for_origin (hb_font_t          *font,
  * Calls the appropriate direction-specific variant (horizontal
  * or vertical) depending on the value of @direction.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1444,7 +1450,7 @@ hb_font_glyph_to_string (hb_font_t      *font,
  *
  * <note>Note: @len == -1 means the string is null-terminated.</note>
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1664,12 +1670,12 @@ hb_font_destroy (hb_font_t *font)
  * @font: #hb_font_t to work upon
  * @key: The user-data key 
  * @data: A pointer to the user data
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the specified font object. 
  *
- * Return value:
+ * Return value: %true if success, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1728,7 +1734,7 @@ hb_font_make_immutable (hb_font_t *font)
  *
  * Tests whether a font object is immutable.
  *
- * Return value: %true if @font is immutable, false otherwise
+ * Return value: %true if @font is immutable, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1828,9 +1834,9 @@ hb_font_get_face (hb_font_t *font)
 /**
  * hb_font_set_funcs:
  * @font: #hb_font_t to work upon
- * @klass: (closure font_data) (destroy destroy) (scope notified):
+ * @klass: (closure font_data) (destroy destroy) (scope notified): The font-functions structure.
  * @font_data: Data to attach to @font
- * @destroy: (optional): The function to call when @font_data is not needed anymore
+ * @destroy: (nullable): The function to call when @font_data is not needed anymore
  *
  * Replaces the font-functions structure attached to a font, updating
  * the font's user-data with @font-data and the @destroy callback.
@@ -1867,7 +1873,7 @@ hb_font_set_funcs (hb_font_t         *font,
  * hb_font_set_funcs_data:
  * @font: #hb_font_t to work upon
  * @font_data: (destroy destroy) (scope notified): Data to attach to @font
- * @destroy: (optional): The function to call when @font_data is not needed anymore
+ * @destroy: (nullable): The function to call when @font_data is not needed anymore
  *
  * Replaces the user data attached to a font, updating the font's 
  * @destroy callback.
@@ -2212,10 +2218,14 @@ hb_font_get_var_coords_normalized (hb_font_t    *font,
 #ifdef HB_EXPERIMENTAL_API
 /**
  * hb_font_get_var_coords_design:
+ * @font: #hb_font_t to work upon
+ * @length: (out): number of coordinates
  *
  * Return value is valid as long as variation coordinates of the font
  * are not modified.
  *
+ * Return value: coordinates array
+ *
  * Since: EXPERIMENTAL
  */
 const float *
@@ -2319,7 +2329,7 @@ hb_font_get_variation_glyph_trampoline (hb_font_t      *font,
  * @ffuncs: The font-functions structure
  * @func: (closure user_data) (destroy destroy) (scope notified): callback function
  * @user_data: data to pass to @func
- * @destroy: (optional): function to call when @user_data is not needed anymore
+ * @destroy: (nullable): function to call when @user_data is not needed anymore
  *
  * Deprecated.  Use hb_font_funcs_set_nominal_glyph_func() and
  * hb_font_funcs_set_variation_glyph_func() instead.
diff --git a/thirdparty/harfbuzz/src/hb-font.h b/thirdparty/harfbuzz/src/hb-font.h
index 05f6c03f47..15dc126523 100644
--- a/thirdparty/harfbuzz/src/hb-font.h
+++ b/thirdparty/harfbuzz/src/hb-font.h
@@ -24,7 +24,7 @@
  * Red Hat Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -37,7 +37,12 @@
 
 HB_BEGIN_DECLS
 
-
+/**
+ * hb_font_t:
+ *
+ * Data type for holding fonts.
+ *
+ */
 typedef struct hb_font_t hb_font_t;
 
 
@@ -141,6 +146,16 @@ typedef struct hb_glyph_extents_t {
 
 /* func types */
 
+/**
+ * hb_font_get_font_extents_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @extents: (out): The font extents retrieved
+ * @user_data: User data pointer passed by the caller
+ *
+ * This method should retrieve the extents for a font.
+ *
+ **/
 typedef hb_bool_t (*hb_font_get_font_extents_func_t) (hb_font_t *font, void *font_data,
 						       hb_font_extents_t *extents,
 						       void *user_data);
@@ -150,7 +165,7 @@ typedef hb_bool_t (*hb_font_get_font_extents_func_t) (hb_font_t *font, void *fon
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
- * This method should retrieve the extents for a font, in horizontal-direction
+ * This method should retrieve the extents for a font, for horizontal-direction
  * text segments. Extents must be returned in an #hb_glyph_extents output
  * parameter.
  * 
@@ -162,7 +177,7 @@ typedef hb_font_get_font_extents_func_t hb_font_get_font_h_extents_func_t;
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
- * This method should retrieve the extents for a font, in vertical-direction
+ * This method should retrieve the extents for a font, for vertical-direction
  * text segments. Extents must be returned in an #hb_glyph_extents output
  * parameter.
  * 
@@ -172,12 +187,19 @@ typedef hb_font_get_font_extents_func_t hb_font_get_font_v_extents_func_t;
 
 /**
  * hb_font_get_nominal_glyph_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @unicode: The Unicode code point to query
+ * @glyph: (out): The glyph ID retrieved
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the nominal glyph ID for a specified Unicode code
  * point. Glyph IDs must be returned in a #hb_codepoint_t output parameter.
  * 
+ * Return value: %true if data found, %false otherwise
+ *
  **/
 typedef hb_bool_t (*hb_font_get_nominal_glyph_func_t) (hb_font_t *font, void *font_data,
 						       hb_codepoint_t unicode,
@@ -186,6 +208,12 @@ typedef hb_bool_t (*hb_font_get_nominal_glyph_func_t) (hb_font_t *font, void *fo
 
 /**
  * hb_font_get_variation_glyph_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @unicode: The Unicode code point to query
+ * @variation_selector: The  variation-selector code point to query
+ * @glyph: (out): The glyph ID retrieved
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
@@ -193,6 +221,8 @@ typedef hb_bool_t (*hb_font_get_nominal_glyph_func_t) (hb_font_t *font, void *fo
  * followed by a specified Variation Selector code point. Glyph IDs must be
  * returned in a #hb_codepoint_t output parameter.
  * 
+ * Return value: %true if data found, %false otherwise
+ *
  **/
 typedef hb_bool_t (*hb_font_get_variation_glyph_func_t) (hb_font_t *font, void *font_data,
 							 hb_codepoint_t unicode, hb_codepoint_t variation_selector,
@@ -202,12 +232,22 @@ typedef hb_bool_t (*hb_font_get_variation_glyph_func_t) (hb_font_t *font, void *
 
 /**
  * hb_font_get_nominal_glyphs_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @count: number of code points to query
+ * @first_unicode: The first Unicode code point to query
+ * @unicode_stride: The stride between successive code points
+ * @first_glyph: (out): The first glyph ID retrieved
+ * @glyph_stride: The stride between successive glyph IDs
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the nominal glyph IDs for a sequence of
  * Unicode code points. Glyph IDs must be returned in a #hb_codepoint_t
  * output parameter.
+ *
+ * Return value: the number of code points processed
  * 
  **/
 typedef unsigned int (*hb_font_get_nominal_glyphs_func_t) (hb_font_t *font, void *font_data,
@@ -220,12 +260,18 @@ typedef unsigned int (*hb_font_get_nominal_glyphs_func_t) (hb_font_t *font, void
 
 /**
  * hb_font_get_glyph_advance_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @glyph: The glyph ID to query
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the advance for a specified glyph. The
  * method must return an #hb_position_t.
  * 
+ * Return value: The advance of @glyph within @font
+ *
  **/
 typedef hb_position_t (*hb_font_get_glyph_advance_func_t) (hb_font_t *font, void *font_data,
 							   hb_codepoint_t glyph,
@@ -257,6 +303,14 @@ typedef hb_font_get_glyph_advance_func_t hb_font_get_glyph_v_advance_func_t;
 
 /**
  * hb_font_get_glyph_advances_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @count: The number of glyph IDs in the sequence queried
+ * @first_glyph: The first glyph ID to query
+ * @glyph_stride: The stride between successive glyph IDs
+ * @first_advance: (out): The first advance retrieved
+ * @advance_stride: The stride between successive advances
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
@@ -295,12 +349,20 @@ typedef hb_font_get_glyph_advances_func_t hb_font_get_glyph_v_advances_func_t;
 
 /**
  * hb_font_get_glyph_origin_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @glyph: The glyph ID to query
+ * @x: (out): The X coordinate of the origin
+ * @y: (out): The Y coordinate of the origin
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the (X,Y) coordinates (in font units) of the
  * origin for a glyph. Each coordinate must be returned in an #hb_position_t
  * output parameter.
+ *
+ * Return value: %true if data found, %false otherwise
  * 
  **/
 typedef hb_bool_t (*hb_font_get_glyph_origin_func_t) (hb_font_t *font, void *font_data,
@@ -314,7 +376,7 @@ typedef hb_bool_t (*hb_font_get_glyph_origin_func_t) (hb_font_t *font, void *fon
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the (X,Y) coordinates (in font units) of the
- * origin for a glyph, in horizontal-direction text segments. Each
+ * origin for a glyph, for horizontal-direction text segments. Each
  * coordinate must be returned in an #hb_position_t output parameter.
  * 
  **/
@@ -326,25 +388,53 @@ typedef hb_font_get_glyph_origin_func_t hb_font_get_glyph_h_origin_func_t;
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the (X,Y) coordinates (in font units) of the
- * origin for a glyph, in vertical-direction text segments. Each coordinate
+ * origin for a glyph, for vertical-direction text segments. Each coordinate
  * must be returned in an #hb_position_t output parameter.
  * 
  **/
 typedef hb_font_get_glyph_origin_func_t hb_font_get_glyph_v_origin_func_t;
 
+/**
+ * hb_font_get_glyph_kerning_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @first_glyph: The glyph ID of the first glyph in the glyph pair
+ * @second_glyph: The glyph ID of the second glyph in the glyph pair
+ * @user_data: User data pointer passed by the caller
+ *
+ * This method should retrieve the kerning-adjustment value for a glyph-pair in
+ * the specified font, for horizontal text segments.
+ *
+ **/
 typedef hb_position_t (*hb_font_get_glyph_kerning_func_t) (hb_font_t *font, void *font_data,
 							   hb_codepoint_t first_glyph, hb_codepoint_t second_glyph,
 							   void *user_data);
+/**
+ * hb_font_get_glyph_h_kerning_func_t:
+ *
+ * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
+ *
+ * This method should retrieve the kerning-adjustment value for a glyph-pair in
+ * the specified font, for horizontal text segments.
+ *
+ **/
 typedef hb_font_get_glyph_kerning_func_t hb_font_get_glyph_h_kerning_func_t;
 
 
 /**
  * hb_font_get_glyph_extents_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @glyph: The glyph ID to query
+ * @extents: (out): The #hb_glyph_extents_t retrieved
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the extents for a specified glyph. Extents must be 
  * returned in an #hb_glyph_extents output parameter.
+ *
+ * Return value: %true if data found, %false otherwise
  * 
  **/
 typedef hb_bool_t (*hb_font_get_glyph_extents_func_t) (hb_font_t *font, void *font_data,
@@ -354,6 +444,13 @@ typedef hb_bool_t (*hb_font_get_glyph_extents_func_t) (hb_font_t *font, void *fo
 
 /**
  * hb_font_get_glyph_contour_point_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @glyph: The glyph ID to query
+ * @point_index: The contour-point index to query
+ * @x: (out): The X value retrieved for the contour point
+ * @y: (out): The Y value retrieved for the contour point
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
@@ -361,6 +458,8 @@ typedef hb_bool_t (*hb_font_get_glyph_extents_func_t) (hb_font_t *font, void *fo
  * specified contour point in a glyph. Each coordinate must be returned as
  * an #hb_position_t output parameter.
  * 
+ * Return value: %true if data found, %false otherwise
+ *
  **/
 typedef hb_bool_t (*hb_font_get_glyph_contour_point_func_t) (hb_font_t *font, void *font_data,
 							     hb_codepoint_t glyph, unsigned int point_index,
@@ -370,12 +469,20 @@ typedef hb_bool_t (*hb_font_get_glyph_contour_point_func_t) (hb_font_t *font, vo
 
 /**
  * hb_font_get_glyph_name_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @glyph: The glyph ID to query
+ * @name: (out) (array length=size): Name string retrieved for the glyph ID
+ * @size: Length of the glyph-name string retrieved
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the glyph name that corresponds to a
  * glyph ID. The name should be returned in a string output parameter.
  * 
+ * Return value: %true if data found, %false otherwise
+ *
  **/
 typedef hb_bool_t (*hb_font_get_glyph_name_func_t) (hb_font_t *font, void *font_data,
 						    hb_codepoint_t glyph,
@@ -384,12 +491,20 @@ typedef hb_bool_t (*hb_font_get_glyph_name_func_t) (hb_font_t *font, void *font_
 
 /**
  * hb_font_get_glyph_from_name_func_t:
+ * @font: #hb_font_t to work upon
+ * @font_data: @font user data pointer
+ * @name: (array length=len): The name string to query
+ * @len: The length of the name queried
+ * @glyph: (out): The glyph ID retrieved
+ * @user_data: User data pointer passed by the caller
  *
  * A virtual method for the #hb_font_funcs_t of an #hb_font_t object.
  *
  * This method should retrieve the glyph ID that corresponds to a glyph-name
  * string. 
  * 
+ * Return value: %true if data found, %false otherwise
+ *
  **/
 typedef hb_bool_t (*hb_font_get_glyph_from_name_func_t) (hb_font_t *font, void *font_data,
 							 const char *name, int len, /* -1 means nul-terminated */
@@ -404,7 +519,7 @@ typedef hb_bool_t (*hb_font_get_glyph_from_name_func_t) (hb_font_t *font, void *
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_font_h_extents_func_t.
  *
@@ -420,7 +535,7 @@ hb_font_funcs_set_font_h_extents_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_font_v_extents_func_t.
  *
@@ -436,7 +551,7 @@ hb_font_funcs_set_font_v_extents_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_nominal_glyph_func_t.
  *
@@ -452,7 +567,7 @@ hb_font_funcs_set_nominal_glyph_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_nominal_glyphs_func_t.
  *
@@ -468,7 +583,7 @@ hb_font_funcs_set_nominal_glyphs_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_variation_glyph_func_t.
  *
@@ -484,7 +599,7 @@ hb_font_funcs_set_variation_glyph_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_h_advance_func_t.
  *
@@ -500,7 +615,7 @@ hb_font_funcs_set_glyph_h_advance_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_v_advance_func_t.
  *
@@ -516,7 +631,7 @@ hb_font_funcs_set_glyph_v_advance_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_h_advances_func_t.
  *
@@ -532,7 +647,7 @@ hb_font_funcs_set_glyph_h_advances_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_v_advances_func_t.
  *
@@ -548,7 +663,7 @@ hb_font_funcs_set_glyph_v_advances_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_h_origin_func_t.
  *
@@ -564,7 +679,7 @@ hb_font_funcs_set_glyph_h_origin_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_v_origin_func_t.
  *
@@ -577,12 +692,12 @@ hb_font_funcs_set_glyph_v_origin_func (hb_font_funcs_t *ffuncs,
 
 /**
  * hb_font_funcs_set_glyph_h_kerning_func:
- * @ffuncs: font functions.
- * @func: (closure user_data) (destroy destroy) (scope notified):
- * @user_data:
- * @destroy:
- *
+ * @ffuncs: A font-function structure
+ * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
+ * @user_data: Data to pass to @func
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
+ * Sets the implementation function for #hb_font_get_glyph_h_kerning_func_t.
  *
  * Since: 0.9.2
  **/
@@ -596,7 +711,7 @@ hb_font_funcs_set_glyph_h_kerning_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_extents_func_t.
  *
@@ -612,7 +727,7 @@ hb_font_funcs_set_glyph_extents_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_contour_point_func_t.
  *
@@ -628,7 +743,7 @@ hb_font_funcs_set_glyph_contour_point_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_name_func_t.
  *
@@ -644,7 +759,7 @@ hb_font_funcs_set_glyph_name_func (hb_font_funcs_t *ffuncs,
  * @ffuncs: A font-function structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_font_get_glyph_from_name_func_t.
  *
diff --git a/thirdparty/harfbuzz/src/hb-ft.cc b/thirdparty/harfbuzz/src/hb-ft.cc
index ab7d6146ce..b82c1a67bd 100644
--- a/thirdparty/harfbuzz/src/hb-ft.cc
+++ b/thirdparty/harfbuzz/src/hb-ft.cc
@@ -84,7 +84,7 @@ struct hb_ft_font_t
   bool symbol; /* Whether selected cmap is symbol cmap. */
   bool unref; /* Whether to destroy ft_face when done. */
 
-  mutable hb_atomic_int_t cached_x_scale;
+  mutable int cached_x_scale;
   mutable hb_advance_cache_t advance_cache;
 };
 
@@ -101,7 +101,7 @@ _hb_ft_font_create (FT_Face ft_face, bool symbol, bool unref)
 
   ft_font->load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;
 
-  ft_font->cached_x_scale.set_relaxed (0);
+  ft_font->cached_x_scale = 0;
   ft_font->advance_cache.init ();
 
   return ft_font;
@@ -179,13 +179,13 @@ hb_ft_font_get_load_flags (hb_font_t *font)
 }
 
 /**
- * hb_ft_get_face:
+ * hb_ft_font_get_face:
  * @font: #hb_font_t to work upon
  *
  * Fetches the FT_Face associated with the specified #hb_font_t
  * font object.
  *
- * Return value: the FT_Face found
+ * Return value: (nullable): the FT_Face found or %NULL
  *
  * Since: 0.9.2
  **/
@@ -202,11 +202,12 @@ hb_ft_font_get_face (hb_font_t *font)
 
 /**
  * hb_ft_font_lock_face:
- * @font:
- *
+ * @font: #hb_font_t to work upon
  *
+ * Gets the FT_Face associated with @font, This face will be kept around until
+ * you call hb_ft_font_unlock_face().
  *
- * Return value:
+ * Return value: (nullable): the FT_Face associated with @font or %NULL
  * Since: 2.6.5
  **/
 FT_Face
@@ -224,11 +225,10 @@ hb_ft_font_lock_face (hb_font_t *font)
 
 /**
  * hb_ft_font_unlock_face:
- * @font:
- *
+ * @font: #hb_font_t to work upon
  *
+ * Releases an FT_Face previously obtained with hb_ft_font_lock_face().
  *
- * Return value:
  * Since: 2.6.5
  **/
 void
@@ -335,10 +335,10 @@ hb_ft_get_glyph_h_advances (hb_font_t* font, void* font_data,
   int load_flags = ft_font->load_flags;
   int mult = font->x_scale < 0 ? -1 : +1;
 
-  if (font->x_scale != ft_font->cached_x_scale.get ())
+  if (font->x_scale != ft_font->cached_x_scale)
   {
     ft_font->advance_cache.clear ();
-    ft_font->cached_x_scale.set (font->x_scale);
+    ft_font->cached_x_scale = font->x_scale;
   }
 
   for (unsigned int i = 0; i < count; i++)
@@ -661,7 +661,7 @@ _hb_ft_reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data
 /**
  * hb_ft_face_create:
  * @ft_face: (destroy destroy) (scope notified): FT_Face to work upon
- * @destroy: (optional): A callback to call when the face object is not needed anymore
+ * @destroy: (nullable): A callback to call when the face object is not needed anymore
  *
  * Creates an #hb_face_t face object from the specified FT_Face.
  *
@@ -771,13 +771,13 @@ hb_ft_face_create_cached (FT_Face ft_face)
 /**
  * hb_ft_font_create:
  * @ft_face: (destroy destroy) (scope notified): FT_Face to work upon
- * @destroy: (optional): A callback to call when the font object is not needed anymore
+ * @destroy: (nullable): A callback to call when the font object is not needed anymore
  *
  * Creates an #hb_font_t font object from the specified FT_Face.
  *
  * <note>Note: You must set the face size on @ft_face before calling
- * hb_ft_font_create() on it. Otherwise, HarfBuzz will not pick up
- * the face size.</note>
+ * hb_ft_font_create() on it. HarfBuzz assumes size is always set and will
+ * access `size` member of FT_Face unconditionally.</note>
  *
  * This variant of the function does not provide any life-cycle management.
  *
@@ -814,7 +814,7 @@ hb_ft_font_create (FT_Face           ft_face,
 }
 
 /**
- * hb_ft_font_has_changed:
+ * hb_ft_font_changed:
  * @font: #hb_font_t to work upon
  *
  * Refreshes the state of @font when the underlying FT_Face has changed.
@@ -884,8 +884,8 @@ hb_ft_font_changed (hb_font_t *font)
  * Creates an #hb_font_t font object from the specified FT_Face.
  *
  * <note>Note: You must set the face size on @ft_face before calling
- * hb_ft_font_create_references() on it. Otherwise, HarfBuzz will not pick up
- * the face size.</note>
+ * hb_ft_font_create_referenced() on it. HarfBuzz assumes size is always set
+ * and will access `size` member of FT_Face unconditionally.</note>
  *
  * This is the preferred variant of the hb_ft_font_create*
  * function family, because it calls FT_Reference_Face() on @ft_face,
diff --git a/thirdparty/harfbuzz/src/hb-gdi.cc b/thirdparty/harfbuzz/src/hb-gdi.cc
index 3a67cef160..dc4659c7f6 100644
--- a/thirdparty/harfbuzz/src/hb-gdi.cc
+++ b/thirdparty/harfbuzz/src/hb-gdi.cc
@@ -70,6 +70,8 @@ fail:
  * hb_gdi_face_create:
  * @hfont: a HFONT object.
  *
+ * Constructs a new face object from the specified GDI HFONT.
+ *
  * Return value: #hb_face_t object corresponding to the given input
  *
  * Since: 2.6.0
diff --git a/thirdparty/harfbuzz/src/hb-gobject-structs.h b/thirdparty/harfbuzz/src/hb-gobject-structs.h
index 6fad8d7019..63467f80df 100644
--- a/thirdparty/harfbuzz/src/hb-gobject-structs.h
+++ b/thirdparty/harfbuzz/src/hb-gobject-structs.h
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_GOBJECT_H_IN
+#if !defined(HB_GOBJECT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-gobject.h> instead."
 #endif
 
@@ -40,47 +40,22 @@ HB_BEGIN_DECLS
 
 /* Object types */
 
-/**
- * hb_gobject_blob_get_type:
- *
- * Since: 0.9.2
- **/
 HB_EXTERN GType
 hb_gobject_blob_get_type (void);
 #define HB_GOBJECT_TYPE_BLOB (hb_gobject_blob_get_type ())
 
-/**
- * hb_gobject_buffer_get_type:
- *
- * Since: 0.9.2
- **/
 HB_EXTERN GType
 hb_gobject_buffer_get_type (void);
 #define HB_GOBJECT_TYPE_BUFFER (hb_gobject_buffer_get_type ())
 
-/**
- * hb_gobject_face_get_type:
- *
- * Since: 0.9.2
- **/
 HB_EXTERN GType
 hb_gobject_face_get_type (void);
 #define HB_GOBJECT_TYPE_FACE (hb_gobject_face_get_type ())
 
-/**
- * hb_gobject_font_get_type:
- *
- * Since: 0.9.2
- **/
 HB_EXTERN GType
 hb_gobject_font_get_type (void);
 #define HB_GOBJECT_TYPE_FONT (hb_gobject_font_get_type ())
 
-/**
- * hb_gobject_font_funcs_get_type:
- *
- * Since: 0.9.2
- **/
 HB_EXTERN GType
 hb_gobject_font_funcs_get_type (void);
 #define HB_GOBJECT_TYPE_FONT_FUNCS (hb_gobject_font_funcs_get_type ())
@@ -97,11 +72,6 @@ HB_EXTERN GType
 hb_gobject_shape_plan_get_type (void);
 #define HB_GOBJECT_TYPE_SHAPE_PLAN (hb_gobject_shape_plan_get_type ())
 
-/**
- * hb_gobject_unicode_funcs_get_type:
- *
- * Since: 0.9.2
- **/
 HB_EXTERN GType
 hb_gobject_unicode_funcs_get_type (void);
 #define HB_GOBJECT_TYPE_UNICODE_FUNCS (hb_gobject_unicode_funcs_get_type ())
diff --git a/thirdparty/harfbuzz/src/hb-graphite2.cc b/thirdparty/harfbuzz/src/hb-graphite2.cc
index d8a72dc2f1..9dafe654c8 100644
--- a/thirdparty/harfbuzz/src/hb-graphite2.cc
+++ b/thirdparty/harfbuzz/src/hb-graphite2.cc
@@ -195,6 +195,11 @@ _hb_graphite2_shaper_font_data_destroy (hb_graphite2_font_data_t *data HB_UNUSED
 #ifndef HB_DISABLE_DEPRECATED
 /**
  * hb_graphite2_font_get_gr_font:
+ * @font: An #hb_font_t
+ *
+ * Always returns %NULL. Use hb_graphite2_face_get_gr_face() instead.
+ *
+ * Return value: (nullable): Graphite2 font associated with @font.
  *
  * Since: 0.9.10
  * Deprecated: 1.4.2
@@ -284,7 +289,7 @@ _hb_graphite2_shape (hb_shape_plan_t    *shape_plan HB_UNUSED,
     return true;
   }
 
-  buffer->ensure (glyph_count);
+  (void) buffer->ensure (glyph_count);
   scratch = buffer->get_scratch_buffer (&scratch_size);
   while ((DIV_CEIL (sizeof (hb_graphite2_cluster_t) * buffer->len, sizeof (*scratch)) +
 	  DIV_CEIL (sizeof (hb_codepoint_t) * glyph_count, sizeof (*scratch))) > scratch_size)
diff --git a/thirdparty/harfbuzz/src/hb-iter.hh b/thirdparty/harfbuzz/src/hb-iter.hh
index 981c5c218c..f7018150e4 100644
--- a/thirdparty/harfbuzz/src/hb-iter.hh
+++ b/thirdparty/harfbuzz/src/hb-iter.hh
@@ -922,7 +922,7 @@ HB_FUNCOBJ (hb_none);
 template <typename C, typename V,
 	  hb_requires (hb_is_iterable (C))>
 inline void
-hb_fill (C& c, const V &v)
+hb_fill (C&& c, const V &v)
 {
   for (auto i = hb_iter (c); i; i++)
     *i = v;
diff --git a/thirdparty/harfbuzz/src/hb-machinery.hh b/thirdparty/harfbuzz/src/hb-machinery.hh
index 54bc60d4c8..3bd5a979b0 100644
--- a/thirdparty/harfbuzz/src/hb-machinery.hh
+++ b/thirdparty/harfbuzz/src/hb-machinery.hh
@@ -80,6 +80,11 @@ static inline Type& StructAfter(TObject &X)
  * Size checking
  */
 
+/* Size signifying variable-sized array */
+#ifndef HB_VAR_ARRAY
+#define HB_VAR_ARRAY 1
+#endif
+
 /* Check _assertion in a method environment */
 #define _DEFINE_INSTANCE_ASSERTION1(_line, _assertion) \
   void _instance_assertion_on_line_##_line () const \
diff --git a/thirdparty/harfbuzz/src/hb-map.cc b/thirdparty/harfbuzz/src/hb-map.cc
index f898bd8f92..f115da2bb8 100644
--- a/thirdparty/harfbuzz/src/hb-map.cc
+++ b/thirdparty/harfbuzz/src/hb-map.cc
@@ -117,7 +117,7 @@ hb_map_destroy (hb_map_t *map)
  * @map: A map
  * @key: The user-data key to set
  * @data: A pointer to the user data to set
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the specified map.
@@ -162,7 +162,7 @@ hb_map_get_user_data (hb_map_t           *map,
  *
  * Tests whether memory allocation for a set was successful.
  *
- * Return value: %true if allocation succeeded, false otherwise
+ * Return value: %true if allocation succeeded, %false otherwise
  *
  * Since: 1.7.7
  **/
@@ -230,7 +230,7 @@ hb_map_del (hb_map_t       *map,
  *
  * Tests whether @key is an element of @map.
  *
- * Return value: %true if @key is found in @map, false otherwise
+ * Return value: %true if @key is found in @map, %false otherwise
  *
  * Since: 1.7.7
  **/
@@ -253,6 +253,9 @@ hb_map_has (const hb_map_t *map,
 void
 hb_map_clear (hb_map_t *map)
 {
+  if (unlikely (hb_object_is_immutable (map)))
+    return;
+
   return map->clear ();
 }
 
diff --git a/thirdparty/harfbuzz/src/hb-map.h b/thirdparty/harfbuzz/src/hb-map.h
index 0c19ac8fb5..6a45a7bdd5 100644
--- a/thirdparty/harfbuzz/src/hb-map.h
+++ b/thirdparty/harfbuzz/src/hb-map.h
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -36,7 +36,11 @@
 HB_BEGIN_DECLS
 
 
-/*
+/**
+ * HB_MAP_VALUE_INVALID:
+ *
+ * Unset #hb_map_t value.
+ *
  * Since: 1.7.7
  */
 #define HB_MAP_VALUE_INVALID ((hb_codepoint_t) -1)
diff --git a/thirdparty/harfbuzz/src/hb-map.hh b/thirdparty/harfbuzz/src/hb-map.hh
index 92c1bd67e5..84fe1d549b 100644
--- a/thirdparty/harfbuzz/src/hb-map.hh
+++ b/thirdparty/harfbuzz/src/hb-map.hh
@@ -97,8 +97,6 @@ struct hb_hashmap_t
 
   void reset ()
   {
-    if (unlikely (hb_object_is_immutable (this)))
-      return;
     successful = true;
     clear ();
   }
@@ -171,8 +169,6 @@ struct hb_hashmap_t
 
   void clear ()
   {
-    if (unlikely (hb_object_is_immutable (this)))
-      return;
     if (items)
       for (auto &_ : hb_iter (items, mask + 1))
 	_.clear ();
@@ -181,6 +177,7 @@ struct hb_hashmap_t
   }
 
   bool is_empty () const { return population == 0; }
+  explicit operator bool () const { return !is_empty (); }
 
   unsigned int get_population () const { return population; }
 
diff --git a/thirdparty/harfbuzz/src/hb-meta.hh b/thirdparty/harfbuzz/src/hb-meta.hh
index 4c0898b1b7..e40d9fd178 100644
--- a/thirdparty/harfbuzz/src/hb-meta.hh
+++ b/thirdparty/harfbuzz/src/hb-meta.hh
@@ -49,6 +49,10 @@ template <bool b> using hb_bool_constant = hb_integral_constant<bool, b>;
 using hb_true_type = hb_bool_constant<true>;
 using hb_false_type = hb_bool_constant<false>;
 
+/* Static-assert as expression. */
+template <bool cond> struct static_assert_expr;
+template <> struct static_assert_expr<true> : hb_false_type {};
+#define static_assert_expr(C) static_assert_expr<C>::value
 
 /* Basic type SFINAE. */
 
@@ -220,6 +224,8 @@ struct hb_reference_wrapper<T&>
 };
 
 
+/* Type traits */
+
 template <typename T>
 using hb_is_integral = hb_bool_constant<
   hb_is_same (hb_decay<T>, char) ||
@@ -292,6 +298,15 @@ template <> struct hb_int_max<unsigned long long>	: hb_integral_constant<unsigne
 #define hb_int_max(T) hb_int_max<T>::value
 
 
+/* Class traits. */
+
+#define HB_DELETE_COPY_ASSIGN(TypeName) \
+  TypeName(const TypeName&) = delete; \
+  void operator=(const TypeName&) = delete
+#define HB_DELETE_CREATE_COPY_ASSIGN(TypeName) \
+  TypeName() = delete; \
+  TypeName(const TypeName&) = delete; \
+  void operator=(const TypeName&) = delete
 
 template <typename T, typename>
 struct _hb_is_destructible : hb_false_type {};
diff --git a/thirdparty/harfbuzz/src/hb-mutex.hh b/thirdparty/harfbuzz/src/hb-mutex.hh
index 56392d049b..2fc8d7ee58 100644
--- a/thirdparty/harfbuzz/src/hb-mutex.hh
+++ b/thirdparty/harfbuzz/src/hb-mutex.hh
@@ -73,24 +73,6 @@ typedef CRITICAL_SECTION hb_mutex_impl_t;
 #define hb_mutex_impl_finish(M)	DeleteCriticalSection (M)
 
 
-#elif !defined(HB_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
-
-#if defined(HAVE_SCHED_H) && defined(HAVE_SCHED_YIELD)
-# include <sched.h>
-# define HB_SCHED_YIELD() sched_yield ()
-#else
-# define HB_SCHED_YIELD() HB_STMT_START {} HB_STMT_END
-#endif
-
-/* This actually is not a totally awful implementation. */
-typedef volatile int hb_mutex_impl_t;
-#define HB_MUTEX_IMPL_INIT	0
-#define hb_mutex_impl_init(M)	*(M) = 0
-#define hb_mutex_impl_lock(M)	HB_STMT_START { while (__sync_lock_test_and_set((M), 1)) HB_SCHED_YIELD (); } HB_STMT_END
-#define hb_mutex_impl_unlock(M)	__sync_lock_release (M)
-#define hb_mutex_impl_finish(M)	HB_STMT_START {} HB_STMT_END
-
-
 #elif defined(HB_NO_MT)
 
 typedef int hb_mutex_impl_t;
diff --git a/thirdparty/harfbuzz/src/hb-object.hh b/thirdparty/harfbuzz/src/hb-object.hh
index 39845a70e7..f3048b1c3e 100644
--- a/thirdparty/harfbuzz/src/hb-object.hh
+++ b/thirdparty/harfbuzz/src/hb-object.hh
@@ -140,9 +140,7 @@ struct hb_lockable_set_t
  * Reference-count.
  */
 
-#define HB_REFERENCE_COUNT_INERT_VALUE 0
-#define HB_REFERENCE_COUNT_POISON_VALUE -0x0000DEAD
-#define HB_REFERENCE_COUNT_INIT {HB_ATOMIC_INT_INIT (HB_REFERENCE_COUNT_INERT_VALUE)}
+#define HB_REFERENCE_COUNT_INIT {0}
 
 struct hb_reference_count_t
 {
@@ -152,9 +150,9 @@ struct hb_reference_count_t
   int get_relaxed () const { return ref_count.get_relaxed (); }
   int inc () const { return ref_count.inc (); }
   int dec () const { return ref_count.dec (); }
-  void fini () { ref_count.set_relaxed (HB_REFERENCE_COUNT_POISON_VALUE); }
+  void fini () { ref_count.set_relaxed (-0x0000DEAD); }
 
-  bool is_inert () const { return ref_count.get_relaxed () == HB_REFERENCE_COUNT_INERT_VALUE; }
+  bool is_inert () const { return !ref_count.get_relaxed (); }
   bool is_valid () const { return ref_count.get_relaxed () > 0; }
 };
 
@@ -197,15 +195,10 @@ struct hb_user_data_array_t
 struct hb_object_header_t
 {
   hb_reference_count_t ref_count;
-  mutable hb_atomic_int_t writable;
+  mutable hb_atomic_int_t writable = 0;
   hb_atomic_ptr_t<hb_user_data_array_t> user_data;
 };
-#define HB_OBJECT_HEADER_STATIC \
-	{ \
-	  HB_REFERENCE_COUNT_INIT, \
-	  HB_ATOMIC_INT_INIT (false), \
-	  HB_ATOMIC_PTR_INIT (nullptr) \
-	}
+#define HB_OBJECT_HEADER_STATIC {}
 
 
 /*
diff --git a/thirdparty/harfbuzz/src/hb-open-file.hh b/thirdparty/harfbuzz/src/hb-open-file.hh
index ac13dd23c3..54c07ff13c 100644
--- a/thirdparty/harfbuzz/src/hb-open-file.hh
+++ b/thirdparty/harfbuzz/src/hb-open-file.hh
@@ -48,7 +48,7 @@ namespace OT {
  */
 
 struct OpenTypeFontFile;
-struct OffsetTable;
+struct OpenTypeOffsetTable;
 struct TTCHeader;
 
 
@@ -78,7 +78,7 @@ typedef struct TableRecord
   DEFINE_SIZE_STATIC (16);
 } OpenTypeTable;
 
-typedef struct OffsetTable
+typedef struct OpenTypeOffsetTable
 {
   friend struct OpenTypeFontFile;
 
@@ -218,7 +218,7 @@ struct TTCHeaderVersion1
   Tag		ttcTag;		/* TrueType Collection ID string: 'ttcf' */
   FixedVersion<>version;	/* Version of the TTC Header (1.0),
 				 * 0x00010000u */
-  LArrayOf<LOffsetTo<OffsetTable>>
+  LArrayOf<LOffsetTo<OpenTypeOffsetTable>>
 		table;		/* Array of offsets to the OffsetTable for each font
 				 * from the beginning of the file */
   public:
diff --git a/thirdparty/harfbuzz/src/hb-open-type.hh b/thirdparty/harfbuzz/src/hb-open-type.hh
index 99634b76f0..dc0ae1d989 100644
--- a/thirdparty/harfbuzz/src/hb-open-type.hh
+++ b/thirdparty/harfbuzz/src/hb-open-type.hh
@@ -53,14 +53,19 @@ namespace OT {
  */
 
 /* Integer types in big-endian order and no alignment requirement */
-template <typename Type, unsigned int Size>
+template <typename Type,
+	  unsigned int Size = sizeof (Type)>
 struct IntType
 {
   typedef Type type;
-  typedef hb_conditional<hb_is_signed (Type), signed, unsigned> wide_type;
 
-  IntType& operator = (wide_type i) { v = i; return *this; }
-  operator wide_type () const { return v; }
+  IntType () = default;
+  explicit constexpr IntType (Type V) : v {V} {}
+  IntType& operator = (Type i) { v = i; return *this; }
+  /* For reason we define cast out operator for signed/unsigned, instead of Type, see:
+   * https://github.com/harfbuzz/harfbuzz/pull/2875/commits/09836013995cab2b9f07577a179ad7b024130467 */
+  operator hb_conditional<hb_is_signed (Type), signed, unsigned> () const { return v; }
+
   bool operator == (const IntType &o) const { return (Type) v == (Type) o.v; }
   bool operator != (const IntType &o) const { return !(*this == o); }
 
@@ -80,14 +85,21 @@ struct IntType
 
     return pb->cmp (*pa);
   }
-  template <typename Type2>
+  template <typename Type2,
+	    hb_enable_if (hb_is_integral (Type2) &&
+			  sizeof (Type2) < sizeof (int) &&
+			  sizeof (Type) < sizeof (int))>
   int cmp (Type2 a) const
   {
     Type b = v;
-    if (sizeof (Type) < sizeof (int) && sizeof (Type2) < sizeof (int))
-      return (int) a - (int) b;
-    else
-      return a < b ? -1 : a == b ? 0 : +1;
+    return (int) a - (int) b;
+  }
+  template <typename Type2,
+	    hb_enable_if (hb_is_convertible (Type2, Type))>
+  int cmp (Type2 a) const
+  {
+    Type b = v;
+    return a < b ? -1 : a == b ? 0 : +1;
   }
   bool sanitize (hb_sanitize_context_t *c) const
   {
@@ -100,12 +112,12 @@ struct IntType
   DEFINE_SIZE_STATIC (Size);
 };
 
-typedef IntType<uint8_t,  1> HBUINT8;	/* 8-bit unsigned integer. */
-typedef IntType<int8_t,   1> HBINT8;	/* 8-bit signed integer. */
-typedef IntType<uint16_t, 2> HBUINT16;	/* 16-bit unsigned integer. */
-typedef IntType<int16_t,  2> HBINT16;	/* 16-bit signed integer. */
-typedef IntType<uint32_t, 4> HBUINT32;	/* 32-bit unsigned integer. */
-typedef IntType<int32_t,  4> HBINT32;	/* 32-bit signed integer. */
+typedef IntType<uint8_t>  HBUINT8;	/* 8-bit unsigned integer. */
+typedef IntType<int8_t>   HBINT8;	/* 8-bit signed integer. */
+typedef IntType<uint16_t> HBUINT16;	/* 16-bit unsigned integer. */
+typedef IntType<int16_t>  HBINT16;	/* 16-bit signed integer. */
+typedef IntType<uint32_t> HBUINT32;	/* 32-bit unsigned integer. */
+typedef IntType<int32_t>  HBINT32;	/* 32-bit signed integer. */
 /* Note: we cannot defined a signed HBINT24 because there's no corresponding C type.
  * Works for unsigned, but not signed, since we rely on compiler for sign-extension. */
 typedef IntType<uint32_t, 3> HBUINT24;	/* 24-bit unsigned integer. */
@@ -163,8 +175,8 @@ struct Tag : HBUINT32
 {
   Tag& operator = (hb_tag_t i) { HBUINT32::operator= (i); return *this; }
   /* What the char* converters return is NOT nul-terminated.  Print using "%.4s" */
-  operator const char* () const { return reinterpret_cast<const char *> (&this->v); }
-  operator char* ()             { return reinterpret_cast<char *> (&this->v); }
+  operator const char* () const { return reinterpret_cast<const char *> (this); }
+  operator char* ()             { return reinterpret_cast<char *> (this); }
   public:
   DEFINE_SIZE_STATIC (4);
 };
diff --git a/thirdparty/harfbuzz/src/hb-ot-cff-common.hh b/thirdparty/harfbuzz/src/hb-ot-cff-common.hh
index e5286cd792..864a27f458 100644
--- a/thirdparty/harfbuzz/src/hb-ot-cff-common.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-cff-common.hh
@@ -183,7 +183,7 @@ struct CFFIndex
     else
     {
       serialize_header(c, + it | hb_map ([] (const byte_str_t &_) { return _.length; }));
-      for (const byte_str_t &_ : +it)
+      for (const auto &_ : +it)
 	_.copy (c);
     }
     return_trace (true);
diff --git a/thirdparty/harfbuzz/src/hb-ot-cff1-table.cc b/thirdparty/harfbuzz/src/hb-ot-cff1-table.cc
index 66b9c8c907..3298fa35ae 100644
--- a/thirdparty/harfbuzz/src/hb-ot-cff1-table.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-cff1-table.cc
@@ -426,7 +426,7 @@ bool OT::cff1::accelerator_t::get_extents (hb_font_t *font, hb_codepoint_t glyph
   else
   {
     extents->x_bearing = font->em_scalef_x (bounds.min.x.to_real ());
-    extents->width = font->em_scalef_x (bounds.max.x.to_real () - bounds.min.x.to_real ());
+    extents->width = font->em_scalef_x (bounds.max.x.to_real ()) - extents->x_bearing;
   }
   if (bounds.min.y >= bounds.max.y)
   {
@@ -436,7 +436,7 @@ bool OT::cff1::accelerator_t::get_extents (hb_font_t *font, hb_codepoint_t glyph
   else
   {
     extents->y_bearing = font->em_scalef_y (bounds.max.y.to_real ());
-    extents->height = font->em_scalef_y (bounds.min.y.to_real () - bounds.max.y.to_real ());
+    extents->height = font->em_scalef_y (bounds.min.y.to_real ()) - extents->y_bearing;
   }
 
   return true;
diff --git a/thirdparty/harfbuzz/src/hb-ot-cff2-table.cc b/thirdparty/harfbuzz/src/hb-ot-cff2-table.cc
index ac0feeee21..879b7cdb23 100644
--- a/thirdparty/harfbuzz/src/hb-ot-cff2-table.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-cff2-table.cc
@@ -127,7 +127,7 @@ bool OT::cff2::accelerator_t::get_extents (hb_font_t *font,
   else
   {
     extents->x_bearing = font->em_scalef_x (param.min_x.to_real ());
-    extents->width = font->em_scalef_x (param.max_x.to_real () - param.min_x.to_real ());
+    extents->width = font->em_scalef_x (param.max_x.to_real ()) - extents->x_bearing;
   }
   if (param.min_y >= param.max_y)
   {
@@ -137,7 +137,7 @@ bool OT::cff2::accelerator_t::get_extents (hb_font_t *font,
   else
   {
     extents->y_bearing = font->em_scalef_y (param.max_y.to_real ());
-    extents->height = font->em_scalef_y (param.min_y.to_real () - param.max_y.to_real ());
+    extents->height = font->em_scalef_y (param.min_y.to_real ()) - extents->y_bearing;
   }
 
   return true;
diff --git a/thirdparty/harfbuzz/src/hb-ot-cmap-table.hh b/thirdparty/harfbuzz/src/hb-ot-cmap-table.hh
index cc48379bb8..878e02ff17 100644
--- a/thirdparty/harfbuzz/src/hb-ot-cmap-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-cmap-table.hh
@@ -95,7 +95,7 @@ struct CmapSubtableFormat4
     HBUINT16 *endCode = c->start_embed<HBUINT16> ();
     hb_codepoint_t prev_endcp = 0xFFFF;
 
-    for (const hb_item_type<Iterator> _ : +it)
+    for (const auto& _ : +it)
     {
       if (prev_endcp != 0xFFFF && prev_endcp + 1u != _.first)
       {
@@ -131,7 +131,7 @@ struct CmapSubtableFormat4
     HBUINT16 *startCode = c->start_embed<HBUINT16> ();
     hb_codepoint_t prev_cp = 0xFFFF;
 
-    for (const hb_item_type<Iterator> _ : +it)
+    for (const auto& _ : +it)
     {
       if (prev_cp == 0xFFFF || prev_cp + 1u != _.first)
       {
@@ -170,7 +170,7 @@ struct CmapSubtableFormat4
     if ((char *)idDelta - (char *)startCode != (int) segcount * (int) HBINT16::static_size)
       return nullptr;
 
-    for (const hb_item_type<Iterator> _ : +it)
+    for (const auto& _ : +it)
     {
       if (_.first == startCode[i])
       {
@@ -696,7 +696,7 @@ struct CmapSubtableFormat12 : CmapSubtableLongSegmented<CmapSubtableFormat12>
     hb_codepoint_t startCharCode = 0xFFFF, endCharCode = 0xFFFF;
     hb_codepoint_t glyphID = 0;
 
-    for (const hb_item_type<Iterator> _ : +it)
+    for (const auto& _ : +it)
     {
       if (startCharCode == 0xFFFF)
       {
diff --git a/thirdparty/harfbuzz/src/hb-ot-color-cbdt-table.hh b/thirdparty/harfbuzz/src/hb-ot-color-cbdt-table.hh
index aaa1c37c64..e285acec3d 100644
--- a/thirdparty/harfbuzz/src/hb-ot-color-cbdt-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-color-cbdt-table.hh
@@ -455,8 +455,8 @@ struct IndexSubtableRecord
     unsigned int old_cbdt_prime_length = bitmap_size_context->cbdt_prime->length;
 
     // Set to invalid state to indicate filling glyphs is not yet started.
-    if (unlikely (!records->resize (records->length + 1)))
-      return_trace (c->serializer->check_success (false));
+    if (unlikely (!c->serializer->check_success (records->resize (records->length + 1))))
+      return_trace (false);
 
     (*records)[records->length - 1].firstGlyphIndex = 1;
     (*records)[records->length - 1].lastGlyphIndex = 0;
@@ -567,8 +567,8 @@ struct IndexSubtableArray
 
     hb_vector_t<hb_pair_t<hb_codepoint_t, const IndexSubtableRecord*>> lookup;
     build_lookup (c, bitmap_size_context, &lookup);
-    if (unlikely (lookup.in_error ()))
-      return c->serializer->check_success (false);
+    if (unlikely (!c->serializer->propagate_error (lookup)))
+      return false;
 
     bitmap_size_context->size = 0;
     bitmap_size_context->num_tables = 0;
diff --git a/thirdparty/harfbuzz/src/hb-ot-color-colr-table.hh b/thirdparty/harfbuzz/src/hb-ot-color-colr-table.hh
index 92a49bb4f4..e2a1ff4662 100644
--- a/thirdparty/harfbuzz/src/hb-ot-color-colr-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-color-colr-table.hh
@@ -214,7 +214,7 @@ struct COLR
 				if (unlikely (!old_record))
 				  return hb_pair_t<bool, BaseGlyphRecord> (false, Null (BaseGlyphRecord));
 
-				BaseGlyphRecord new_record;
+				BaseGlyphRecord new_record = {};
 				new_record.glyphId = new_gid;
 				new_record.numLayers = old_record->numLayers;
 				return hb_pair_t<bool, BaseGlyphRecord> (true, new_record);
diff --git a/thirdparty/harfbuzz/src/hb-ot-color.cc b/thirdparty/harfbuzz/src/hb-ot-color.cc
index 0e7203a88b..4170b71317 100644
--- a/thirdparty/harfbuzz/src/hb-ot-color.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-color.cc
@@ -37,9 +37,6 @@
 #include "hb-ot-color-sbix-table.hh"
 #include "hb-ot-color-svg-table.hh"
 
-#include <stdlib.h>
-#include <string.h>
-
 
 /**
  * SECTION:hb-ot-color
@@ -64,7 +61,7 @@
  *
  * Tests whether a face includes a `CPAL` color-palette table.
  *
- * Return value: true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 2.1.0
  */
@@ -195,7 +192,7 @@ hb_ot_color_palette_get_colors (hb_face_t     *face,
  *
  * Tests whether a face includes any `COLR` color layers.
  *
- * Return value: true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 2.1.0
  */
@@ -242,7 +239,7 @@ hb_ot_color_glyph_get_layers (hb_face_t           *face,
  *
  * Tests whether a face includes any `SVG` glyph images.
  *
- * Return value: true if data found, false otherwise.
+ * Return value: %true if data found, %false otherwise.
  *
  * Since: 2.1.0
  */
@@ -280,7 +277,7 @@ hb_ot_color_glyph_reference_svg (hb_face_t *face, hb_codepoint_t glyph)
  *
  * Tests whether a face has PNG glyph images (either in `CBDT` or `sbix` tables).
  *
- * Return value: true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 2.1.0
  */
diff --git a/thirdparty/harfbuzz/src/hb-ot-color.h b/thirdparty/harfbuzz/src/hb-ot-color.h
index 4f37a4386f..c23ce4de44 100644
--- a/thirdparty/harfbuzz/src/hb-ot-color.h
+++ b/thirdparty/harfbuzz/src/hb-ot-color.h
@@ -26,7 +26,7 @@
  * Google Author(s): Sascha Brawer, Behdad Esfahbod
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
@@ -66,6 +66,8 @@ hb_ot_color_palette_color_get_name_id (hb_face_t *face,
  * @HB_OT_COLOR_PALETTE_FLAG_USABLE_WITH_DARK_BACKGROUND: Flag indicating that the color
  *   palette is appropriate to use when displaying the font on a dark background such as black.
  *
+ * Flags that describe the properties of color palette.
+ *
  * Since: 2.1.0
  */
 typedef enum { /*< flags >*/
@@ -95,6 +97,8 @@ hb_ot_color_has_layers (hb_face_t *face);
 
 /**
  * hb_ot_color_layer_t:
+ * @glyph: the glyph ID of the layer
+ * @color_index: the palette color index of the layer
  *
  * Pairs of glyph and color index.
  *
diff --git a/thirdparty/harfbuzz/src/hb-ot-deprecated.h b/thirdparty/harfbuzz/src/hb-ot-deprecated.h
index 2e75deef2d..ce6b6fef11 100644
--- a/thirdparty/harfbuzz/src/hb-ot-deprecated.h
+++ b/thirdparty/harfbuzz/src/hb-ot-deprecated.h
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
@@ -41,6 +41,13 @@ HB_BEGIN_DECLS
 
 
 /* https://github.com/harfbuzz/harfbuzz/issues/1734 */
+/**
+ * HB_MATH_GLYPH_PART_FLAG_EXTENDER:
+ *
+ * Use #HB_OT_MATH_GLYPH_PART_FLAG_EXTENDER instead.
+ *
+ * Deprecated: 2.5.1
+ */
 #define HB_MATH_GLYPH_PART_FLAG_EXTENDER HB_OT_MATH_GLYPH_PART_FLAG_EXTENDER
 
 
@@ -71,6 +78,8 @@ hb_ot_tag_from_language (hb_language_t language);
 /**
  * HB_OT_VAR_NO_AXIS_INDEX:
  *
+ * Do not use.
+ *
  * Since: 1.4.2
  * Deprecated: 2.2.0
  */
@@ -78,6 +87,13 @@ hb_ot_tag_from_language (hb_language_t language);
 
 /**
  * hb_ot_var_axis_t:
+ * @tag: axis tag
+ * @name_id: axis name identifier
+ * @min_value: minimum value of the axis
+ * @default_value: default value of the axis
+ * @max_value: maximum value of the axis
+ *
+ * Use #hb_ot_var_axis_info_t instead.
  *
  * Since: 1.4.2
  * Deprecated: 2.2.0
diff --git a/thirdparty/harfbuzz/src/hb-ot-font.h b/thirdparty/harfbuzz/src/hb-ot-font.h
index 80eaa54b1a..e7959d1ae2 100644
--- a/thirdparty/harfbuzz/src/hb-ot-font.h
+++ b/thirdparty/harfbuzz/src/hb-ot-font.h
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod, Roozbeh Pournader
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-glyf-table.hh b/thirdparty/harfbuzz/src/hb-ot-glyf-table.hh
index 5470bd96da..5352156f02 100644
--- a/thirdparty/harfbuzz/src/hb-ot-glyf-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-glyf-table.hh
@@ -186,7 +186,7 @@ struct glyf
     | hb_map (&SubsetGlyph::padded_size)
     ;
 
-    if (c->serializer->in_error ()) return_trace (false);
+    if (unlikely (c->serializer->in_error ())) return_trace (false);
     return_trace (c->serializer->check_success (_add_loca_and_head (c->plan,
 								    padded_offsets)));
   }
@@ -944,9 +944,9 @@ struct glyf
 	    return;
 	  }
 	  extents->x_bearing = font->em_scalef_x (min_x);
-	  extents->width = font->em_scalef_x (max_x - min_x);
+	  extents->width = font->em_scalef_x (max_x) - extents->x_bearing;
 	  extents->y_bearing = font->em_scalef_y (max_y);
-	  extents->height = font->em_scalef_y (min_y - max_y);
+	  extents->height = font->em_scalef_y (min_y) - extents->y_bearing;
 	}
 
 	protected:
diff --git a/thirdparty/harfbuzz/src/hb-ot-head-table.hh b/thirdparty/harfbuzz/src/hb-ot-head-table.hh
index 5613a96dbf..ac588e3af6 100644
--- a/thirdparty/harfbuzz/src/hb-ot-head-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-head-table.hh
@@ -43,7 +43,7 @@ namespace OT {
 
 struct head
 {
-  friend struct OffsetTable;
+  friend struct OpenTypeOffsetTable;
 
   static constexpr hb_tag_t tableTag = HB_OT_TAG_head;
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-layout-common.hh b/thirdparty/harfbuzz/src/hb-ot-layout-common.hh
index 6ab950a322..0ba7e3c061 100644
--- a/thirdparty/harfbuzz/src/hb-ot-layout-common.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-layout-common.hh
@@ -1128,7 +1128,7 @@ struct Lookup
     out->lookupType = lookupType;
     out->lookupFlag = lookupFlag;
 
-    const hb_set_t *glyphset = c->plan->glyphset ();
+    const hb_set_t *glyphset = c->plan->glyphset_gsub ();
     unsigned int lookup_type = get_type ();
     + hb_iter (get_subtables <TSubTable> ())
     | hb_filter ([this, glyphset, lookup_type] (const OffsetTo<TSubTable> &_) { return (this+_).intersects (glyphset, lookup_type); })
@@ -1251,8 +1251,9 @@ struct CoverageFormat1
   {
     /* TODO Speed up, using hb_set_next() and bsearch()? */
     unsigned int count = glyphArray.len;
+    const HBGlyphID *arr = glyphArray.arrayZ;
     for (unsigned int i = 0; i < count; i++)
-      if (glyphs->has (glyphArray[i]))
+      if (glyphs->has (arr[i]))
 	return true;
     return false;
   }
@@ -1356,18 +1357,21 @@ struct CoverageFormat2
   bool intersects (const hb_set_t *glyphs) const
   {
     /* TODO Speed up, using hb_set_next() and bsearch()? */
-    unsigned int count = rangeRecord.len;
-    for (unsigned int i = 0; i < count; i++)
-      if (rangeRecord[i].intersects (glyphs))
+    /* TODO(iter) Rewrite as dagger. */
+    unsigned count = rangeRecord.len;
+    const RangeRecord *arr = rangeRecord.arrayZ;
+    for (unsigned i = 0; i < count; i++)
+      if (arr[i].intersects (glyphs))
 	return true;
     return false;
   }
   bool intersects_coverage (const hb_set_t *glyphs, unsigned int index) const
   {
-    unsigned int i;
-    unsigned int count = rangeRecord.len;
-    for (i = 0; i < count; i++) {
-      const RangeRecord &range = rangeRecord[i];
+    /* TODO(iter) Rewrite as dagger. */
+    unsigned count = rangeRecord.len;
+    const RangeRecord *arr = rangeRecord.arrayZ;
+    for (unsigned i = 0; i < count; i++) {
+      const RangeRecord &range = arr[i];
       if (range.value <= index &&
 	  index < (unsigned int) range.value + (range.last - range.first) &&
 	  range.intersects (glyphs))
@@ -1502,7 +1506,7 @@ struct Coverage
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto it =
@@ -1729,7 +1733,7 @@ struct ClassDefFormat1
 	       hb_map_t *klass_map = nullptr /*OUT*/) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->_glyphset_gsub;
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     hb_sorted_vector_t<HBGlyphID> glyphs;
@@ -1784,7 +1788,7 @@ struct ClassDefFormat1
   }
 
   template <typename set_t>
-  bool collect_class (set_t *glyphs, unsigned int klass) const
+  bool collect_class (set_t *glyphs, unsigned klass) const
   {
     unsigned int count = classValue.len;
     for (unsigned int i = 0; i < count; i++)
@@ -1802,7 +1806,7 @@ struct ClassDefFormat1
       if (classValue[iter - start]) return true;
     return false;
   }
-  bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const
+  bool intersects_class (const hb_set_t *glyphs, uint16_t klass) const
   {
     unsigned int count = classValue.len;
     if (klass == 0)
@@ -1815,8 +1819,12 @@ struct ClassDefFormat1
       if (hb_set_next (glyphs, &g)) return true;
       /* Fall through. */
     }
+    /* TODO Speed up, using set overlap first? */
+    /* TODO(iter) Rewrite as dagger. */
+    HBUINT16 k {klass};
+    const HBUINT16 *arr = classValue.arrayZ;
     for (unsigned int i = 0; i < count; i++)
-      if (classValue[i] == klass && glyphs->has (startGlyph + i))
+      if (arr[i] == k && glyphs->has (startGlyph + i))
 	return true;
     return false;
   }
@@ -1898,7 +1906,7 @@ struct ClassDefFormat2
 	       hb_map_t *klass_map = nullptr /*OUT*/) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->_glyphset_gsub;
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     hb_sorted_vector_t<HBGlyphID> glyphs;
@@ -1961,11 +1969,14 @@ struct ClassDefFormat2
     /* TODO Speed up, using hb_set_next() and bsearch()? */
     unsigned int count = rangeRecord.len;
     for (unsigned int i = 0; i < count; i++)
-      if (rangeRecord[i].intersects (glyphs))
+    {
+      const auto& range = rangeRecord[i];
+      if (range.intersects (glyphs) && range.value)
 	return true;
+    }
     return false;
   }
-  bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const
+  bool intersects_class (const hb_set_t *glyphs, uint16_t klass) const
   {
     unsigned int count = rangeRecord.len;
     if (klass == 0)
@@ -1984,8 +1995,12 @@ struct ClassDefFormat2
 	return true;
       /* Fall through. */
     }
+    /* TODO Speed up, using set overlap first? */
+    /* TODO(iter) Rewrite as dagger. */
+    HBUINT16 k {klass};
+    const RangeRecord *arr = rangeRecord.arrayZ;
     for (unsigned int i = 0; i < count; i++)
-      if (rangeRecord[i].value == klass && rangeRecord[i].intersects (glyphs))
+      if (arr[i].value == k && arr[i].intersects (glyphs))
 	return true;
     return false;
   }
diff --git a/thirdparty/harfbuzz/src/hb-ot-layout-gpos-table.hh b/thirdparty/harfbuzz/src/hb-ot-layout-gpos-table.hh
index 2217d298fb..f523e35c00 100644
--- a/thirdparty/harfbuzz/src/hb-ot-layout-gpos-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-layout-gpos-table.hh
@@ -566,6 +566,26 @@ struct AnchorMatrix
     return_trace (true);
   }
 
+  bool subset (hb_subset_context_t *c,
+	       unsigned cols,
+	       const hb_map_t *klass_mapping) const
+  {
+    TRACE_SUBSET (this);
+    auto *out = c->serializer->start_embed (*this);
+
+    auto indexes =
+    + hb_range (rows * cols)
+    | hb_filter ([=] (unsigned index) { return klass_mapping->has (index % cols); })
+    ;
+
+    out->serialize (c->serializer,
+                    (unsigned) rows,
+                    this,
+                    c->plan->layout_variation_idx_map,
+                    indexes);
+    return_trace (true);
+  }
+
   bool sanitize (hb_sanitize_context_t *c, unsigned int cols) const
   {
     TRACE_SANITIZE (this);
@@ -755,7 +775,7 @@ struct SinglePosFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto it =
@@ -870,7 +890,7 @@ struct SinglePosFormat2
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     unsigned sub_length = valueFormat.get_len ();
@@ -1129,7 +1149,7 @@ struct PairSet
     if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
     out->len = 0;
 
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     unsigned len1 = valueFormats[0].get_len ();
@@ -1250,7 +1270,7 @@ struct PairPosFormat1
   {
     TRACE_SUBSET (this);
 
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
@@ -1441,7 +1461,7 @@ struct PairPosFormat2
 		})
     ;
 
-    const hb_set_t &glyphset = *c->plan->_glyphset_gsub;
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto it =
@@ -1728,7 +1748,7 @@ struct CursivePosFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
@@ -1904,7 +1924,7 @@ struct MarkBasePosFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
@@ -2025,10 +2045,37 @@ typedef AnchorMatrix LigatureAttach;	/* component-major--
 					 * mark-minor--
 					 * ordered by class--zero-based. */
 
-typedef OffsetListOf<LigatureAttach> LigatureArray;
-					/* Array of LigatureAttach
-					 * tables ordered by
-					 * LigatureCoverage Index */
+/* Array of LigatureAttach tables ordered by LigatureCoverage Index */
+struct LigatureArray : OffsetListOf<LigatureAttach>
+{
+  template <typename Iterator,
+	    hb_requires (hb_is_iterator (Iterator))>
+  bool subset (hb_subset_context_t *c,
+	       Iterator		    coverage,
+	       unsigned		    class_count,
+	       const hb_map_t	   *klass_mapping) const
+  {
+    TRACE_SUBSET (this);
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
+
+    auto *out = c->serializer->start_embed (this);
+    if (unlikely (!c->serializer->extend_min (out)))  return_trace (false);
+
+    for (const auto _ : + hb_zip (coverage, *this)
+		  | hb_filter (glyphset, hb_first))
+    {
+      auto *matrix = out->serialize_append (c->serializer);
+      if (unlikely (!matrix)) return_trace (false);
+
+      matrix->serialize_subset (c,
+				_.second,
+				this,
+				class_count,
+				klass_mapping);
+    }
+    return_trace (this->len);
+  }
+};
 
 struct MarkLigPosFormat1
 {
@@ -2130,8 +2177,56 @@ struct MarkLigPosFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    // TODO(subset)
-    return_trace (false);
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
+    const hb_map_t &glyph_map = *c->plan->glyph_map;
+
+    auto *out = c->serializer->start_embed (*this);
+    if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
+    out->format = format;
+
+    hb_map_t klass_mapping;
+    Markclass_closure_and_remap_indexes (this+markCoverage, this+markArray, glyphset, &klass_mapping);
+
+    if (!klass_mapping.get_population ()) return_trace (false);
+    out->classCount = klass_mapping.get_population ();
+
+    auto mark_iter =
+    + hb_zip (this+markCoverage, this+markArray)
+    | hb_filter (glyphset, hb_first)
+    ;
+
+    auto new_mark_coverage =
+    + mark_iter
+    | hb_map_retains_sorting (hb_first)
+    | hb_map_retains_sorting (glyph_map)
+    ;
+
+    if (!out->markCoverage.serialize (c->serializer, out)
+			  .serialize (c->serializer, new_mark_coverage))
+      return_trace (false);
+
+    out->markArray.serialize (c->serializer, out)
+		  .serialize (c->serializer,
+                              &klass_mapping,
+                              c->plan->layout_variation_idx_map,
+                              &(this+markArray),
+                              + mark_iter
+                              | hb_map (hb_second));
+
+    auto new_ligature_coverage =
+    + hb_iter (this + ligatureCoverage)
+    | hb_filter (glyphset)
+    | hb_map_retains_sorting (glyph_map)
+    ;
+
+    if (!out->ligatureCoverage.serialize (c->serializer, out)
+			      .serialize (c->serializer, new_ligature_coverage))
+      return_trace (false);
+
+    out->ligatureArray.serialize_subset (c, ligatureArray, this,
+                                         hb_iter (this+ligatureCoverage), classCount, &klass_mapping);
+
+    return_trace (true);
   }
 
   bool sanitize (hb_sanitize_context_t *c) const
@@ -2164,6 +2259,7 @@ struct MarkLigPosFormat1
   DEFINE_SIZE_STATIC (12);
 };
 
+
 struct MarkLigPos
 {
   template <typename context_t, typename ...Ts>
@@ -2288,7 +2384,7 @@ struct MarkMarkPosFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
diff --git a/thirdparty/harfbuzz/src/hb-ot-layout-gsub-table.hh b/thirdparty/harfbuzz/src/hb-ot-layout-gsub-table.hh
index 2f41d67819..5f10ecb7ee 100644
--- a/thirdparty/harfbuzz/src/hb-ot-layout-gsub-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-layout-gsub-table.hh
@@ -356,7 +356,7 @@ struct Sequence
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     if (!intersects (&glyphset)) return_trace (false);
@@ -447,7 +447,7 @@ struct MultipleSubstFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
@@ -582,7 +582,7 @@ struct AlternateSet
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto it =
@@ -682,7 +682,7 @@ struct AlternateSubstFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
@@ -840,7 +840,7 @@ struct Ligature
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     if (!intersects (&glyphset) || !glyphset.has (ligGlyph)) return_trace (false);
@@ -1058,7 +1058,7 @@ struct LigatureSubstFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
diff --git a/thirdparty/harfbuzz/src/hb-ot-layout-gsubgpos.hh b/thirdparty/harfbuzz/src/hb-ot-layout-gsubgpos.hh
index cb95e6dcd5..36a95ead15 100644
--- a/thirdparty/harfbuzz/src/hb-ot-layout-gsubgpos.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-layout-gsubgpos.hh
@@ -89,7 +89,7 @@ struct hb_closure_context_t :
 
   bool is_lookup_done (unsigned int lookup_index)
   {
-    if (done_lookups->in_error ())
+    if (unlikely (done_lookups->in_error ()))
       return true;
 
     /* Have we visited this lookup with the current set of glyphs? */
@@ -146,7 +146,6 @@ struct hb_closure_lookups_context_t :
     if (is_lookup_visited (lookup_index))
       return;
 
-    set_lookup_visited (lookup_index);
     nesting_level_left--;
     recurse_func (this, lookup_index);
     nesting_level_left++;
@@ -163,10 +162,10 @@ struct hb_closure_lookups_context_t :
 
   bool is_lookup_visited (unsigned lookup_index)
   {
-    if (lookup_count++ > HB_MAX_LOOKUP_INDICES)
+    if (unlikely (lookup_count++ > HB_MAX_LOOKUP_INDICES))
       return true;
 
-    if (visited_lookups->in_error ())
+    if (unlikely (visited_lookups->in_error ()))
       return true;
 
     return visited_lookups->has (lookup_index);
@@ -660,7 +659,7 @@ struct hb_ot_apply_context_t :
   void replace_glyph (hb_codepoint_t glyph_index) const
   {
     _set_glyph_props (glyph_index);
-    buffer->replace_glyph (glyph_index);
+    (void) buffer->replace_glyph (glyph_index);
   }
   void replace_glyph_inplace (hb_codepoint_t glyph_index) const
   {
@@ -671,13 +670,13 @@ struct hb_ot_apply_context_t :
 				    unsigned int class_guess) const
   {
     _set_glyph_props (glyph_index, class_guess, true);
-    buffer->replace_glyph (glyph_index);
+    (void) buffer->replace_glyph (glyph_index);
   }
   void output_glyph_for_component (hb_codepoint_t glyph_index,
 				   unsigned int class_guess) const
   {
     _set_glyph_props (glyph_index, class_guess, false, true);
-    buffer->output_glyph (glyph_index);
+    (void) buffer->output_glyph (glyph_index);
   }
 };
 
@@ -1044,7 +1043,7 @@ static inline bool ligate_input (hb_ot_apply_context_t *c,
 				    hb_min (this_comp, last_num_components);
 	  _hb_glyph_info_set_lig_props_for_mark (&buffer->cur(), lig_id, new_lig_comp);
       }
-      buffer->next_glyph ();
+      (void) buffer->next_glyph ();
     }
 
     last_lig_id = _hb_glyph_info_get_lig_id (&buffer->cur());
@@ -1188,7 +1187,7 @@ static inline bool apply_lookup (hb_ot_apply_context_t *c,
 
     /* Don't recurse to ourself at same position.
      * Note that this test is too naive, it doesn't catch longer loops. */
-    if (idx == 0 && lookupRecord[i].lookupListIndex == c->lookup_index)
+    if (unlikely (idx == 0 && lookupRecord[i].lookupListIndex == c->lookup_index))
       continue;
 
     if (unlikely (!buffer->move_to (match_positions[idx])))
@@ -1226,7 +1225,8 @@ static inline bool apply_lookup (hb_ot_apply_context_t *c,
      *     mean that n match positions where removed, as there might
      *     have been marks and default-ignorables in the sequence.  We
      *     should instead drop match positions between current-position
-     *     and current-position + n instead.
+     *     and current-position + n instead. Though, am not sure which
+     *     one is better. Both cases have valid uses. Sigh.
      *
      * It should be possible to construct tests for both of these cases.
      */
@@ -1272,7 +1272,7 @@ static inline bool apply_lookup (hb_ot_apply_context_t *c,
       match_positions[next] += delta;
   }
 
-  buffer->move_to (end);
+  (void) buffer->move_to (end);
 
   return_trace (true);
 }
@@ -1389,9 +1389,11 @@ struct Rule
 			    lookup_context);
   }
 
-  void closure_lookups (hb_closure_lookups_context_t *c) const
+  void closure_lookups (hb_closure_lookups_context_t *c,
+                        ContextClosureLookupContext &lookup_context) const
   {
     if (unlikely (c->lookup_limit_exceeded ())) return;
+    if (!intersects (c->glyphs, lookup_context)) return;
 
     const UnsizedArrayOf<LookupRecord> &lookupRecord = StructAfter<UnsizedArrayOf<LookupRecord>>
 						       (inputZ.as_array (inputCount ? inputCount - 1 : 0));
@@ -1521,14 +1523,13 @@ struct RuleSet
     ;
   }
 
-  void closure_lookups (hb_closure_lookups_context_t *c) const
+  void closure_lookups (hb_closure_lookups_context_t *c,
+                        ContextClosureLookupContext &lookup_context) const
   {
     if (unlikely (c->lookup_limit_exceeded ())) return;
-
-    return
     + hb_iter (rule)
     | hb_map (hb_add (this))
-    | hb_apply ([&] (const Rule &_) { _.closure_lookups (c); })
+    | hb_apply ([&] (const Rule &_) { _.closure_lookups (c, lookup_context); })
     ;
   }
 
@@ -1647,9 +1648,16 @@ struct ContextFormat1
 
   void closure_lookups (hb_closure_lookups_context_t *c) const
   {
-    + hb_iter (ruleSet)
+    struct ContextClosureLookupContext lookup_context = {
+      {intersects_glyph},
+      nullptr
+    };
+
+    + hb_zip (this+coverage, ruleSet)
+    | hb_filter (*c->glyphs, hb_first)
+    | hb_map (hb_second)
     | hb_map (hb_add (this))
-    | hb_apply ([&] (const RuleSet &_) { _.closure_lookups (c); })
+    | hb_apply ([&] (const RuleSet &_) { _.closure_lookups (c, lookup_context); })
     ;
   }
 
@@ -1700,7 +1708,7 @@ struct ContextFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
@@ -1791,10 +1799,24 @@ struct ContextFormat2
 
   void closure_lookups (hb_closure_lookups_context_t *c) const
   {
+    if (!(this+coverage).intersects (c->glyphs))
+      return;
+
+    const ClassDef &class_def = this+classDef;
+
+    struct ContextClosureLookupContext lookup_context = {
+      {intersects_class},
+      &class_def
+    };
+
     + hb_iter (ruleSet)
     | hb_map (hb_add (this))
-    | hb_apply ([&] (const RuleSet &_) { _.closure_lookups (c); })
-    ;
+    | hb_enumerate
+    | hb_filter ([&] (const hb_pair_t<unsigned, const RuleSet &> p)
+    { return class_def.intersects_class (c->glyphs, p.first); })
+    | hb_map (hb_second)
+    | hb_apply ([&] (const RuleSet & _)
+    { _.closure_lookups (c, lookup_context); });
   }
 
   void collect_variation_indices (hb_collect_variation_indices_context_t *c) const {}
@@ -1860,8 +1882,8 @@ struct ContextFormat2
     const hb_map_t *lookup_map = c->table_tag == HB_OT_TAG_GSUB ? c->plan->gsub_lookups : c->plan->gpos_lookups;
     bool ret = true;
     int non_zero_index = 0, index = 0;
-    for (const hb_pair_t<unsigned, const OffsetTo<RuleSet>&> _ : + hb_enumerate (ruleSet)
-								 | hb_filter (klass_map, hb_first))
+    for (const auto& _ : + hb_enumerate (ruleSet)
+			 | hb_filter (klass_map, hb_first))
     {
       auto *o = out->ruleSet.serialize_append (c->serializer);
       if (unlikely (!o))
@@ -1945,6 +1967,8 @@ struct ContextFormat3
 
   void closure_lookups (hb_closure_lookups_context_t *c) const
   {
+    if (!intersects (c->glyphs))
+      return;
     const LookupRecord *lookupRecord = &StructAfter<LookupRecord> (coverageZ.as_array (glyphCount));
     recurse_lookups (c, lookupCount, lookupRecord);
   }
@@ -2010,6 +2034,7 @@ struct ContextFormat3
 
     for (const OffsetTo<Coverage>& offset : coverages)
     {
+      /* TODO(subset) This looks like should not be necessary to write this way. */
       auto *o = c->serializer->allocate_size<OffsetTo<Coverage>> (OffsetTo<Coverage>::static_size);
       if (unlikely (!o)) return_trace (false);
       if (!o->serialize_subset (c, offset, this)) return_trace (false);
@@ -2238,9 +2263,11 @@ struct ChainRule
 				  lookup_context);
   }
 
-  void closure_lookups (hb_closure_lookups_context_t *c) const
+  void closure_lookups (hb_closure_lookups_context_t *c,
+                        ChainContextClosureLookupContext &lookup_context) const
   {
     if (unlikely (c->lookup_limit_exceeded ())) return;
+    if (!intersects (c->glyphs, lookup_context)) return;
 
     const HeadlessArrayOf<HBUINT16> &input = StructAfter<HeadlessArrayOf<HBUINT16>> (backtrack);
     const ArrayOf<HBUINT16> &lookahead = StructAfter<ArrayOf<HBUINT16>> (input);
@@ -2296,11 +2323,7 @@ struct ChainRule
   {
     c->copy (len);
     for (const auto g : it)
-    {
-      HBUINT16 gid;
-      gid = g;
-      c->copy (gid);
-    }
+      c->copy ((HBUINT16) g);
   }
 
   ChainRule* copy (hb_serialize_context_t *c,
@@ -2328,12 +2351,19 @@ struct ChainRule
 				       | hb_map (mapping));
 
     const ArrayOf<LookupRecord> &lookupRecord = StructAfter<ArrayOf<LookupRecord>> (lookahead);
-    HBUINT16 lookupCount;
-    lookupCount = lookupRecord.len;
-    if (!c->copy (lookupCount)) return_trace (nullptr);
 
-    for (unsigned i = 0; i < (unsigned) lookupCount; i++)
+    HBUINT16* lookupCount = c->embed (&(lookupRecord.len));
+    if (!lookupCount) return_trace (nullptr);
+
+    for (unsigned i = 0; i < lookupRecord.len; i++)
+    {
+      if (!lookup_map->has (lookupRecord[i].lookupListIndex))
+      {
+        (*lookupCount)--;
+        continue;
+      }
       if (!c->copy (lookupRecord[i], lookup_map)) return_trace (nullptr);
+    }
 
     return_trace (out);
   }
@@ -2351,7 +2381,7 @@ struct ChainRule
 
     if (!backtrack_map)
     {
-      const hb_set_t &glyphset = *c->plan->glyphset ();
+      const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
       if (!hb_all (backtrack, glyphset) ||
 	  !hb_all (input, glyphset) ||
 	  !hb_all (lookahead, glyphset))
@@ -2424,14 +2454,14 @@ struct ChainRuleSet
     ;
   }
 
-  void closure_lookups (hb_closure_lookups_context_t *c) const
+  void closure_lookups (hb_closure_lookups_context_t *c,
+                        ChainContextClosureLookupContext &lookup_context) const
   {
     if (unlikely (c->lookup_limit_exceeded ())) return;
 
-    return
     + hb_iter (rule)
     | hb_map (hb_add (this))
-    | hb_apply ([&] (const ChainRule &_) { _.closure_lookups (c); })
+    | hb_apply ([&] (const ChainRule &_) { _.closure_lookups (c, lookup_context); })
     ;
   }
 
@@ -2552,9 +2582,16 @@ struct ChainContextFormat1
 
   void closure_lookups (hb_closure_lookups_context_t *c) const
   {
-    + hb_iter (ruleSet)
+    struct ChainContextClosureLookupContext lookup_context = {
+      {intersects_glyph},
+      {nullptr, nullptr, nullptr}
+    };
+
+    + hb_zip (this+coverage, ruleSet)
+    | hb_filter (*c->glyphs, hb_first)
+    | hb_map (hb_second)
     | hb_map (hb_add (this))
-    | hb_apply ([&] (const ChainRuleSet &_) { _.closure_lookups (c); })
+    | hb_apply ([&] (const ChainRuleSet &_) { _.closure_lookups (c, lookup_context); })
     ;
   }
 
@@ -2604,7 +2641,7 @@ struct ChainContextFormat1
   bool subset (hb_subset_context_t *c) const
   {
     TRACE_SUBSET (this);
-    const hb_set_t &glyphset = *c->plan->glyphset ();
+    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
     const hb_map_t &glyph_map = *c->plan->glyph_map;
 
     auto *out = c->serializer->start_embed (*this);
@@ -2701,9 +2738,28 @@ struct ChainContextFormat2
 
   void closure_lookups (hb_closure_lookups_context_t *c) const
   {
+    if (!(this+coverage).intersects (c->glyphs))
+      return;
+
+    const ClassDef &backtrack_class_def = this+backtrackClassDef;
+    const ClassDef &input_class_def = this+inputClassDef;
+    const ClassDef &lookahead_class_def = this+lookaheadClassDef;
+
+    struct ChainContextClosureLookupContext lookup_context = {
+      {intersects_class},
+      {&backtrack_class_def,
+       &input_class_def,
+       &lookahead_class_def}
+    };
+
     + hb_iter (ruleSet)
     | hb_map (hb_add (this))
-    | hb_apply ([&] (const ChainRuleSet &_) { _.closure_lookups (c); })
+    | hb_enumerate
+    | hb_filter([&] (unsigned klass)
+    { return input_class_def.intersects_class (c->glyphs, klass); }, hb_first)
+    | hb_map (hb_second)
+    | hb_apply ([&] (const ChainRuleSet &_)
+    { _.closure_lookups (c, lookup_context); })
     ;
   }
 
@@ -2779,24 +2835,23 @@ struct ChainContextFormat2
     out->coverage.serialize_subset (c, coverage, this);
 
     hb_map_t backtrack_klass_map;
-    out->backtrackClassDef.serialize_subset (c, backtrackClassDef, this, &backtrack_klass_map);
-    if (unlikely (!c->serializer->check_success (!backtrack_klass_map.in_error ())))
-      return_trace (false);
-
-    // subset inputClassDef based on glyphs survived in Coverage subsetting
     hb_map_t input_klass_map;
-    out->inputClassDef.serialize_subset (c, inputClassDef, this, &input_klass_map);
-    if (unlikely (!c->serializer->check_success (!input_klass_map.in_error ())))
-      return_trace (false);
-
     hb_map_t lookahead_klass_map;
+
+    out->backtrackClassDef.serialize_subset (c, backtrackClassDef, this, &backtrack_klass_map);
+    // TODO: subset inputClassDef based on glyphs survived in Coverage subsetting
+    out->inputClassDef.serialize_subset (c, inputClassDef, this, &input_klass_map);
     out->lookaheadClassDef.serialize_subset (c, lookaheadClassDef, this, &lookahead_klass_map);
-    if (unlikely (!c->serializer->check_success (!lookahead_klass_map.in_error ())))
+
+    if (unlikely (!c->serializer->propagate_error (backtrack_klass_map,
+						   input_klass_map,
+						   lookahead_klass_map)))
       return_trace (false);
 
-    unsigned non_zero_index = 0, index = 0;
+    int non_zero_index = -1, index = 0;
     bool ret = true;
     const hb_map_t *lookup_map = c->table_tag == HB_OT_TAG_GSUB ? c->plan->gsub_lookups : c->plan->gpos_lookups;
+    auto last_non_zero = c->serializer->snapshot ();
     for (const OffsetTo<ChainRuleSet>& _ : + hb_enumerate (ruleSet)
 					   | hb_filter (input_klass_map, hb_first)
 					   | hb_map (hb_second))
@@ -2812,19 +2867,20 @@ struct ChainContextFormat2
 			       &backtrack_klass_map,
 			       &input_klass_map,
 			       &lookahead_klass_map))
+      {
+        last_non_zero = c->serializer->snapshot ();
 	non_zero_index = index;
+      }
 
       index++;
     }
 
     if (!ret) return_trace (ret);
 
-    //prune empty trailing ruleSets
-    --index;
-    while (index > non_zero_index)
-    {
-      out->ruleSet.pop ();
-      index--;
+    // prune empty trailing ruleSets
+    if (index > non_zero_index) {
+      c->serializer->revert (last_non_zero);
+      out->ruleSet.len = non_zero_index + 1;
     }
 
     return_trace (bool (out->ruleSet));
@@ -2908,6 +2964,9 @@ struct ChainContextFormat3
 
   void closure_lookups (hb_closure_lookups_context_t *c) const
   {
+    if (!intersects (c->glyphs))
+      return;
+
     const OffsetArrayOf<Coverage> &input = StructAfter<OffsetArrayOf<Coverage>> (backtrack);
     const OffsetArrayOf<Coverage> &lookahead = StructAfter<OffsetArrayOf<Coverage>> (input);
     const ArrayOf<LookupRecord> &lookup = StructAfter<ArrayOf<LookupRecord>> (lookahead);
@@ -2986,13 +3045,16 @@ struct ChainContextFormat3
     TRACE_SERIALIZE (this);
     auto *out = c->serializer->start_embed<OffsetArrayOf<Coverage>> ();
 
-    if (unlikely (!c->serializer->allocate_size<HBUINT16> (HBUINT16::static_size))) return_trace (false);
+    if (unlikely (!c->serializer->allocate_size<HBUINT16> (HBUINT16::static_size)))
+      return_trace (false);
 
-    + it
-    | hb_apply (subset_offset_array (c, *out, base))
-    ;
+    for (auto& offset : it) {
+      auto *o = out->serialize_append (c->serializer);
+      if (unlikely (!o) || !o->serialize_subset (c, offset, base))
+        return_trace (false);
+    }
 
-    return_trace (out->len);
+    return_trace (true);
   }
 
   bool subset (hb_subset_context_t *c) const
@@ -3113,6 +3175,24 @@ struct ExtensionFormat1
 		  extensionLookupType != T::SubTable::Extension);
   }
 
+  bool subset (hb_subset_context_t *c) const
+  {
+    TRACE_SUBSET (this);
+
+    auto *out = c->serializer->start_embed (this);
+    if (unlikely (!out || !c->serializer->extend_min (out))) return_trace (false);
+
+    out->format = format;
+    out->extensionLookupType = extensionLookupType;
+
+    const auto& src_offset =
+        reinterpret_cast<const LOffsetTo<typename T::SubTable> &> (extensionOffset);
+    auto& dest_offset =
+        reinterpret_cast<LOffsetTo<typename T::SubTable> &> (out->extensionOffset);
+
+    return_trace (dest_offset.serialize_subset (c, src_offset, this, get_type ()));
+  }
+
   protected:
   HBUINT16	format;			/* Format identifier. Set to 1. */
   HBUINT16	extensionLookupType;	/* Lookup type of subtable referenced
@@ -3143,6 +3223,18 @@ struct Extension
     }
   }
 
+  // Specialization of dispatch for subset. dispatch() normally just
+  // dispatches to the sub table this points too, but for subset
+  // we need to run subset on this subtable too.
+  template <typename ...Ts>
+  typename hb_subset_context_t::return_t dispatch (hb_subset_context_t *c, Ts&&... ds) const
+  {
+    switch (u.format) {
+    case 1: return u.format1.subset (c);
+    default: return c->default_return_value ();
+    }
+  }
+
   template <typename context_t, typename ...Ts>
   typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
   {
@@ -3320,20 +3412,34 @@ struct GSUBGPOS
     return_trace (true);
   }
 
-  void closure_features (const hb_map_t *lookup_indexes, /* IN */
-			 hb_set_t       *feature_indexes /* OUT */) const
+  void prune_features (const hb_map_t *lookup_indices, /* IN */
+                       hb_set_t       *feature_indices /* IN/OUT */) const
   {
-    unsigned int feature_count = hb_min (get_feature_count (), (unsigned) HB_MAX_FEATURES);
-    for (unsigned i = 0; i < feature_count; i++)
+#ifndef HB_NO_VAR
+    // This is the set of feature indices which have alternate versions defined
+    // if the FeatureVariation's table and the alternate version(s) intersect the
+    // set of lookup indices.
+    hb_set_t alternate_feature_indices;
+    if (version.to_int () >= 0x00010001u)
+      (this+featureVars).closure_features (lookup_indices, &alternate_feature_indices);
+    if (unlikely (alternate_feature_indices.in_error())) {
+      feature_indices->successful = false;
+      return;
+    }
+#endif
+
+    for (unsigned i : feature_indices->iter())
     {
       const Feature& f = get_feature (i);
-      if ((!f.featureParams.is_null ()) || f.intersects_lookup_indexes (lookup_indexes))
-	feature_indexes->add (i);
-    }
+
+      if (f.featureParams.is_null ()
+	  && !f.intersects_lookup_indexes (lookup_indices)
 #ifndef HB_NO_VAR
-    if (version.to_int () >= 0x00010001u)
-      (this+featureVars).closure_features (lookup_indexes, feature_indexes);
+          && !alternate_feature_indices.has (i)
 #endif
+	  )
+	feature_indices->del (i);
+    }
   }
 
   unsigned int get_size () const
diff --git a/thirdparty/harfbuzz/src/hb-ot-layout.cc b/thirdparty/harfbuzz/src/hb-ot-layout.cc
index f25f0f9e23..89df949b26 100644
--- a/thirdparty/harfbuzz/src/hb-ot-layout.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-layout.cc
@@ -76,7 +76,7 @@
  * Tests whether a face includes any kerning data in the 'kern' table.
  * Does NOT test for kerning lookups in the GPOS table.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  **/
 bool
@@ -92,7 +92,7 @@ hb_ot_layout_has_kerning (hb_face_t *face)
  * Tests whether a face includes any state-machine kerning in the 'kern' table.
  * Does NOT examine the GPOS table.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  **/
 bool
@@ -112,7 +112,7 @@ hb_ot_layout_has_machine_kerning (hb_face_t *face)
  *
  * Does NOT examine the GPOS table.
  *
- * Return value: %true is data found, false otherwise
+ * Return value: %true is data found, %false otherwise
  *
  **/
 bool
@@ -268,7 +268,7 @@ _hb_ot_layout_set_glyph_props (hb_font_t *font,
  *
  * Tests whether a face has any glyph classes defined in its GDEF table.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  **/
 hb_bool_t
@@ -322,7 +322,7 @@ hb_ot_layout_get_glyphs_in_class (hb_face_t                  *face,
  * @face: The #hb_face_t to work on
  * @glyph: The #hb_codepoint_t code point to query
  * @start_offset: offset of the first attachment point to retrieve
- * @point_count: (inout) (allow-none): Input = the maximum number of attachment points to return;
+ * @point_count: (inout) (optional): Input = the maximum number of attachment points to return;
  *               Output = the actual number of attachment points returned (may be zero)
  * @point_array: (out) (array length=point_count): The array of attachment points found for the query
  *
@@ -350,7 +350,7 @@ hb_ot_layout_get_attach_points (hb_face_t      *face,
  * @direction: The #hb_direction_t text direction to use
  * @glyph: The #hb_codepoint_t code point to query
  * @start_offset: offset of the first caret position to retrieve
- * @caret_count: (inout) (allow-none): Input = the maximum number of caret positions to return;
+ * @caret_count: (inout) (optional): Input = the maximum number of caret positions to return;
  *               Output = the actual number of caret positions returned (may be zero)
  * @caret_array: (out) (array length=caret_count): The array of caret positions found for the query
  *
@@ -410,9 +410,9 @@ get_gsubgpos_table (hb_face_t *face,
 /**
  * hb_ot_layout_table_get_script_tags:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @start_offset: offset of the first script tag to retrieve
- * @script_count: (inout) (allow-none): Input = the maximum number of script tags to return;
+ * @script_count: (inout) (optional): Input = the maximum number of script tags to return;
  *                Output = the actual number of script tags returned (may be zero)
  * @script_tags: (out) (array length=script_count): The array of #hb_tag_t script tags found for the query
  *
@@ -437,14 +437,14 @@ hb_ot_layout_table_get_script_tags (hb_face_t    *face,
 /**
  * hb_ot_layout_table_find_script:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_tag: #hb_tag_t of the script tag requested
  * @script_index: (out): The index of the requested script tag
  *
  * Fetches the index if a given script tag in the specified face's GSUB table
  * or GPOS table.
  *
- * Return value: %true if the script is found, false otherwise
+ * Return value: %true if the script is found, %false otherwise
  *
  **/
 hb_bool_t
@@ -481,7 +481,7 @@ hb_ot_layout_table_find_script (hb_face_t    *face,
 /**
  * hb_ot_layout_table_choose_script:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_tags: Array of #hb_tag_t script tags
  * @script_index: (out): The index of the requested script tag
  * @chosen_script: (out): #hb_tag_t of the script tag requested
@@ -504,11 +504,22 @@ hb_ot_layout_table_choose_script (hb_face_t      *face,
 /**
  * hb_ot_layout_table_select_script:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_count: Number of script tags in the array
  * @script_tags: Array of #hb_tag_t script tags
- * @script_index: (out): The index of the requested script
- * @chosen_script: (out): #hb_tag_t of the requested script
+ * @script_index: (out) (optional): The index of the requested script
+ * @chosen_script: (out) (optional): #hb_tag_t of the requested script
+ *
+ * Selects an OpenType script for @table_tag from the @script_tags array.
+ *
+ * If the table does not have any of the requested scripts, then `DFLT`,
+ * `dflt`, and `latn` tags are tried in that order. If the table still does not
+ * have any of these scripts, @script_index and @chosen_script are set to
+ * #HB_OT_LAYOUT_NO_SCRIPT_INDEX.
+ *
+ * Return value:
+ * %true if one of the requested scripts is selected, %false if a fallback
+ * script is selected or if no scripts are selected.
  *
  * Since: 2.0.0
  **/
@@ -566,9 +577,9 @@ hb_ot_layout_table_select_script (hb_face_t      *face,
 /**
  * hb_ot_layout_table_get_feature_tags:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @start_offset: offset of the first feature tag to retrieve
- * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
+ * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return;
  *                 Output = the actual number of feature tags returned (may be zero)
  * @feature_tags: (out) (array length=feature_count): Array of feature tags found in the table
  *
@@ -591,14 +602,14 @@ hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
 /**
  * hb_ot_layout_table_find_feature:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @feature_tag: The #hb_tag_t og the requested feature tag
  * @feature_index: (out): The index of the requested feature
  *
  * Fetches the index for a given feature tag in the specified face's GSUB table
  * or GPOS table.
  *
- * Return value: %true if the feature is found, false otherwise
+ * Return value: %true if the feature is found, %false otherwise
  **/
 bool
 hb_ot_layout_table_find_feature (hb_face_t    *face,
@@ -626,10 +637,10 @@ hb_ot_layout_table_find_feature (hb_face_t    *face,
 /**
  * hb_ot_layout_script_get_language_tags:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_index: The index of the requested script tag
  * @start_offset: offset of the first language tag to retrieve
- * @language_count: (inout) (allow-none): Input = the maximum number of language tags to return;
+ * @language_count: (inout) (optional): Input = the maximum number of language tags to return;
  *                  Output = the actual number of language tags returned (may be zero)
  * @language_tags: (out) (array length=language_count): Array of language tags found in the table
  *
@@ -655,7 +666,7 @@ hb_ot_layout_script_get_language_tags (hb_face_t    *face,
 /**
  * hb_ot_layout_script_find_language:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_index: The index of the requested script tag
  * @language_tag: The #hb_tag_t of the requested language
  * @language_index: The index of the requested language
@@ -663,7 +674,7 @@ hb_ot_layout_script_get_language_tags (hb_face_t    *face,
  * Fetches the index of a given language tag in the specified face's GSUB table
  * or GPOS table, underneath the specified script tag.
  *
- * Return value: %true if the language tag is found, false otherwise
+ * Return value: %true if the language tag is found, %false otherwise
  *
  * Since: ??
  * Deprecated: ??
@@ -688,7 +699,7 @@ hb_ot_layout_script_find_language (hb_face_t    *face,
 /**
  * hb_ot_layout_script_select_language:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_index: The index of the requested script tag
  * @language_count: The number of languages in the specified script
  * @language_tags: The array of language tags
@@ -697,7 +708,7 @@ hb_ot_layout_script_find_language (hb_face_t    *face,
  * Fetches the index of a given language tag in the specified face's GSUB table
  * or GPOS table, underneath the specified script index.
  *
- * Return value: %true if the language tag is found, false otherwise
+ * Return value: %true if the language tag is found, %false otherwise
  *
  * Since: 2.0.0
  **/
@@ -731,7 +742,7 @@ hb_ot_layout_script_select_language (hb_face_t      *face,
 /**
  * hb_ot_layout_language_get_required_feature_index:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_index: The index of the requested script tag
  * @language_index: The index of the requested language tag
  * @feature_index: (out): The index of the requested feature
@@ -739,7 +750,7 @@ hb_ot_layout_script_select_language (hb_face_t      *face,
  * Fetches the index of a requested feature in the given face's GSUB or GPOS table,
  * underneath the specified script and language.
  *
- * Return value: %true if the feature is found, false otherwise
+ * Return value: %true if the feature is found, %false otherwise
  *
  **/
 hb_bool_t
@@ -761,7 +772,7 @@ hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
 /**
  * hb_ot_layout_language_get_required_feature:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_index: The index of the requested script tag
  * @language_index: The index of the requested language tag
  * @feature_index: (out): The index of the requested feature
@@ -770,7 +781,7 @@ hb_ot_layout_language_get_required_feature_index (hb_face_t    *face,
  * Fetches the tag of a requested feature index in the given face's GSUB or GPOS table,
  * underneath the specified script and language.
  *
- * Return value: %true if the feature is found, false otherwise
+ * Return value: %true if the feature is found, %false otherwise
  *
  * Since: 0.9.30
  **/
@@ -796,11 +807,11 @@ hb_ot_layout_language_get_required_feature (hb_face_t    *face,
 /**
  * hb_ot_layout_language_get_feature_indexes:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_index: The index of the requested script tag
  * @language_index: The index of the requested language tag
  * @start_offset: offset of the first feature tag to retrieve
- * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
+ * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return;
  *                 Output: the actual number of feature tags returned (may be zero)
  * @feature_indexes: (out) (array length=feature_count): The array of feature indexes found for the query
  *
@@ -827,11 +838,11 @@ hb_ot_layout_language_get_feature_indexes (hb_face_t    *face,
 /**
  * hb_ot_layout_language_get_feature_tags:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_index: The index of the requested script tag
  * @language_index: The index of the requested language tag
  * @start_offset: offset of the first feature tag to retrieve
- * @feature_count: (inout) (allow-none): Input = the maximum number of feature tags to return;
+ * @feature_count: (inout) (optional): Input = the maximum number of feature tags to return;
  *                 Output = the actual number of feature tags returned (may be zero)
  * @feature_tags: (out) (array length=feature_count): The array of #hb_tag_t feature tags found for the query
  *
@@ -868,7 +879,7 @@ hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
 /**
  * hb_ot_layout_language_find_feature:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @script_index: The index of the requested script tag
  * @language_index: The index of the requested language tag
  * @feature_tag: #hb_tag_t of the feature tag requested
@@ -877,7 +888,7 @@ hb_ot_layout_language_get_feature_tags (hb_face_t    *face,
  * Fetches the index of a given feature tag in the specified face's GSUB table
  * or GPOS table, underneath the specified script and language.
  *
- * Return value: %true if the feature is found, false otherwise
+ * Return value: %true if the feature is found, %false otherwise
  *
  **/
 hb_bool_t
@@ -910,10 +921,10 @@ hb_ot_layout_language_find_feature (hb_face_t    *face,
 /**
  * hb_ot_layout_feature_get_lookups:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @feature_index: The index of the requested feature
  * @start_offset: offset of the first lookup to retrieve
- * @lookup_count: (inout) (allow-none): Input = the maximum number of lookups to return;
+ * @lookup_count: (inout) (optional): Input = the maximum number of lookups to return;
  *                Output = the actual number of lookups returned (may be zero)
  * @lookup_indexes: (out) (array length=lookup_count): The array of lookup indexes found for the query
  *
@@ -944,7 +955,7 @@ hb_ot_layout_feature_get_lookups (hb_face_t    *face,
 /**
  * hb_ot_layout_table_get_lookup_count:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  *
  * Fetches the total number of lookups enumerated in the specified
  * face's GSUB table or GPOS table.
@@ -1101,7 +1112,7 @@ script_collect_features (hb_collect_features_context_t *c,
 /**
  * hb_ot_layout_collect_features:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @scripts: The array of scripts to collect features for
  * @languages: The array of languages to collect features for
  * @features: The array of features to collect
@@ -1152,7 +1163,7 @@ hb_ot_layout_collect_features (hb_face_t      *face,
 /**
  * hb_ot_layout_collect_lookups:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @scripts: The array of scripts to collect lookups for
  * @languages: The array of languages to collect lookups for
  * @features: The array of features to collect lookups for
@@ -1191,7 +1202,7 @@ hb_ot_layout_collect_lookups (hb_face_t      *face,
 /**
  * hb_ot_layout_lookup_collect_glyphs:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @lookup_index: The index of the feature lookup to query
  * @glyphs_before: (out): Array of glyphs preceding the substitution range
  * @glyphs_input: (out): Array of input glyphs that would be substituted by the lookup
@@ -1243,7 +1254,7 @@ hb_ot_layout_lookup_collect_glyphs (hb_face_t    *face,
 /**
  * hb_ot_layout_table_find_feature_variations:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @coords: The variation coordinates to query
  * @num_coords: The number of variation coordinates
  * @variations_index: (out): The array of feature variations found for the query
@@ -1268,11 +1279,11 @@ hb_ot_layout_table_find_feature_variations (hb_face_t    *face,
 /**
  * hb_ot_layout_feature_with_variations_get_lookups:
  * @face: #hb_face_t to work upon
- * @table_tag: HB_OT_TAG_GSUB or HB_OT_TAG_GPOS
+ * @table_tag: #HB_OT_TAG_GSUB or #HB_OT_TAG_GPOS
  * @feature_index: The index of the feature to query
  * @variations_index: The index of the feature variation to query
  * @start_offset: offset of the first lookup to retrieve
- * @lookup_count: (inout) (allow-none): Input = the maximum number of lookups to return;
+ * @lookup_count: (inout) (optional): Input = the maximum number of lookups to return;
  *                Output = the actual number of lookups returned (may be zero)
  * @lookup_indexes: (out) (array length=lookup_count): The array of lookups found for the query
  *
@@ -1310,7 +1321,7 @@ hb_ot_layout_feature_with_variations_get_lookups (hb_face_t    *face,
  *
  * Tests whether the specified face includes any GSUB substitutions.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  **/
 hb_bool_t
@@ -1331,7 +1342,7 @@ hb_ot_layout_has_substitution (hb_face_t *face)
  * Tests whether a specified lookup in the specified face would
  * trigger a substitution on the given glyph sequence.
  *
- * Return value: %true if a substitution would be triggered, false otherwise
+ * Return value: %true if a substitution would be triggered, %false otherwise
  *
  * Since: 0.9.7
  **/
@@ -1488,7 +1499,9 @@ hb_ot_layout_lookups_substitute_closure (hb_face_t      *face,
  * hb_ot_layout_has_positioning:
  * @face: #hb_face_t to work upon
  *
- * Return value: %true if the face has GPOS data, false otherwise
+ * Tests whether the specified face includes any GPOS positioning.
+ *
+ * Return value: %true if the face has GPOS data, %false otherwise
  *
  **/
 hb_bool_t
@@ -1561,7 +1574,7 @@ hb_ot_layout_position_finish_offsets (hb_font_t *font, hb_buffer_t *buffer)
  * For more information on this distinction, see the [`size` feature documentation](
  * https://docs.microsoft.com/en-us/typography/opentype/spec/features_pt#tag-size).
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 0.9.10
  **/
@@ -1610,22 +1623,22 @@ hb_ot_layout_get_size_params (hb_face_t       *face,
  * @face: #hb_face_t to work upon
  * @table_tag: table tag to query, "GSUB" or "GPOS".
  * @feature_index: index of feature to query.
- * @label_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
+ * @label_id: (out) (optional): The ‘name’ table name ID that specifies a string
  *            for a user-interface label for this feature. (May be NULL.)
- * @tooltip_id: (out) (allow-none): The ‘name’ table name ID that specifies a string
+ * @tooltip_id: (out) (optional): The ‘name’ table name ID that specifies a string
  *              that an application can use for tooltip text for this
  *              feature. (May be NULL.)
- * @sample_id: (out) (allow-none): The ‘name’ table name ID that specifies sample text
+ * @sample_id: (out) (optional): The ‘name’ table name ID that specifies sample text
  *             that illustrates the effect of this feature. (May be NULL.)
- * @num_named_parameters: (out) (allow-none):  Number of named parameters. (May be zero.)
- * @first_param_id: (out) (allow-none): The first ‘name’ table name ID used to specify
+ * @num_named_parameters: (out) (optional):  Number of named parameters. (May be zero.)
+ * @first_param_id: (out) (optional): The first ‘name’ table name ID used to specify
  *                  strings for user-interface labels for the feature
  *                  parameters. (Must be zero if numParameters is zero.)
  *
  * Fetches name indices from feature parameters for "Stylistic Set" ('ssXX') or
  * "Character Variant" ('cvXX') features.
  *
- * Return value: %true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 2.0.0
  **/
@@ -1685,7 +1698,7 @@ hb_ot_layout_feature_get_name_ids (hb_face_t       *face,
  * @table_tag: table tag to query, "GSUB" or "GPOS".
  * @feature_index: index of feature to query.
  * @start_offset: offset of the first character to retrieve
- * @char_count: (inout) (allow-none): Input = the maximum number of characters to return;
+ * @char_count: (inout) (optional): Input = the maximum number of characters to return;
  *              Output = the actual number of characters returned (may be zero)
  * @characters: (out caller-allocates) (array length=char_count): A buffer pointer.
  *              The Unicode codepoints of the characters for which this feature provides
@@ -1769,7 +1782,7 @@ apply_forward (OT::hb_ot_apply_context_t *c,
     if (applied)
       ret = true;
     else
-      buffer->next_glyph ();
+      (void) buffer->next_glyph ();
   }
   return ret;
 }
@@ -1907,7 +1920,7 @@ hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c,
  * @baseline_tag: a baseline tag
  * @direction: text direction.
  * @script_tag:  script tag.
- * @language_tag: language tag.
+ * @language_tag: language tag, currently unused.
  * @coord: (out): baseline value if found.
  *
  * Fetches a baseline value from the face.
@@ -1964,7 +1977,7 @@ struct hb_get_glyph_alternates_dispatch_t :
  * @lookup_index: index of the feature lookup to query.
  * @glyph: a glyph id.
  * @start_offset: starting offset.
- * @alternate_count: (inout) (allow-none): Input = the maximum number of alternate glyphs to return;
+ * @alternate_count: (inout) (optional): Input = the maximum number of alternate glyphs to return;
  *                   Output = the actual number of alternate glyphs returned (may be zero).
  * @alternate_glyphs: (out caller-allocates) (array length=alternate_count): A glyphs buffer.
  *                    Alternate glyphs associated with the glyph id.
diff --git a/thirdparty/harfbuzz/src/hb-ot-layout.h b/thirdparty/harfbuzz/src/hb-ot-layout.h
index 545d5f7fc4..d47ba0fc92 100644
--- a/thirdparty/harfbuzz/src/hb-ot-layout.h
+++ b/thirdparty/harfbuzz/src/hb-ot-layout.h
@@ -24,7 +24,7 @@
  * Red Hat Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
@@ -38,10 +38,35 @@
 HB_BEGIN_DECLS
 
 
+/**
+ * HB_OT_TAG_BASE:
+ *
+ * OpenType [Baseline Table](https://docs.microsoft.com/en-us/typography/opentype/spec/base).
+ */
 #define HB_OT_TAG_BASE HB_TAG('B','A','S','E')
+/**
+ * HB_OT_TAG_GDEF:
+ *
+ * OpenType [Glyph Definition Table](https://docs.microsoft.com/en-us/typography/opentype/spec/gdef).
+ */
 #define HB_OT_TAG_GDEF HB_TAG('G','D','E','F')
+/**
+ * HB_OT_TAG_GSUB:
+ *
+ * OpenType [Glyph Substitution Table](https://docs.microsoft.com/en-us/typography/opentype/spec/gsub).
+ */
 #define HB_OT_TAG_GSUB HB_TAG('G','S','U','B')
+/**
+ * HB_OT_TAG_GPOS:
+ *
+ * OpenType [Glyph Positioning Table](https://docs.microsoft.com/en-us/typography/opentype/spec/gpos).
+ */
 #define HB_OT_TAG_GPOS HB_TAG('G','P','O','S')
+/**
+ * HB_OT_TAG_JSTF:
+ *
+ * OpenType [Justification Table](https://docs.microsoft.com/en-us/typography/opentype/spec/jstf).
+ */
 #define HB_OT_TAG_JSTF HB_TAG('J','S','T','F')
 
 
@@ -49,18 +74,34 @@ HB_BEGIN_DECLS
  * Script & Language tags.
  */
 
+/**
+ * HB_OT_TAG_DEFAULT_SCRIPT:
+ *
+ * OpenType script tag, `DFLT`, for features that are not script-specific.
+ *
+ */
 #define HB_OT_TAG_DEFAULT_SCRIPT	HB_TAG ('D', 'F', 'L', 'T')
+/**
+ * HB_OT_TAG_DEFAULT_LANGUAGE:
+ *
+ * OpenType language tag, `dflt`. Not a valid language tag, but some fonts
+ * mistakenly use it.
+ */
 #define HB_OT_TAG_DEFAULT_LANGUAGE	HB_TAG ('d', 'f', 'l', 't')
 
 /**
  * HB_OT_MAX_TAGS_PER_SCRIPT:
  *
+ * Maximum number of OpenType tags that can correspond to a give #hb_script_t.
+ *
  * Since: 2.0.0
  **/
 #define HB_OT_MAX_TAGS_PER_SCRIPT	3u
 /**
  * HB_OT_MAX_TAGS_PER_LANGUAGE:
  *
+ * Maximum number of OpenType tags that can correspond to a give #hb_language_t.
+ *
  * Since: 2.0.0
  **/
 #define HB_OT_MAX_TAGS_PER_LANGUAGE	3u
@@ -144,9 +185,29 @@ hb_ot_layout_get_ligature_carets (hb_font_t      *font,
  * GSUB/GPOS feature query and enumeration interface
  */
 
+/**
+ * HB_OT_LAYOUT_NO_SCRIPT_INDEX:
+ *
+ * Special value for script index indicating unsupported script.
+ */
 #define HB_OT_LAYOUT_NO_SCRIPT_INDEX		0xFFFFu
+/**
+ * HB_OT_LAYOUT_NO_FEATURE_INDEX:
+ *
+ * Special value for feature index indicating unsupported feature.
+ */
 #define HB_OT_LAYOUT_NO_FEATURE_INDEX		0xFFFFu
+/**
+ * HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX:
+ *
+ * Special value for language index indicating default or unsupported language.
+ */
 #define HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX	0xFFFFu
+/**
+ * HB_OT_LAYOUT_NO_VARIATIONS_INDEX:
+ *
+ * Special value for variations index indicating unsupported variation.
+ */
 #define HB_OT_LAYOUT_NO_VARIATIONS_INDEX	0xFFFFFFFFu
 
 HB_EXTERN unsigned int
@@ -433,7 +494,7 @@ hb_ot_layout_feature_get_characters (hb_face_t      *face,
  * @HB_OT_LAYOUT_BASELINE_TAG_MATH: The baseline about which mathematical characters are centered.
  * In vertical writing mode when mathematical characters rotated 90 degrees clockwise, are centered.
  *
- * Baseline tags from https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags
+ * Baseline tags from [Baseline Tags](https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags) registry.
  *
  * Since: 2.6.0
  */
@@ -446,6 +507,7 @@ typedef enum {
   HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT	= HB_TAG ('i','d','t','p'),
   HB_OT_LAYOUT_BASELINE_TAG_MATH			= HB_TAG ('m','a','t','h'),
 
+  /*< private >*/
   _HB_OT_LAYOUT_BASELINE_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/
 } hb_ot_layout_baseline_tag_t;
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-layout.hh b/thirdparty/harfbuzz/src/hb-ot-layout.hh
index f3bb15581a..ac61bc70de 100644
--- a/thirdparty/harfbuzz/src/hb-ot-layout.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-layout.hh
@@ -315,12 +315,13 @@ _hb_glyph_info_get_unicode_space_fallback_type (const hb_glyph_info_t *info)
 }
 
 static inline bool _hb_glyph_info_ligated (const hb_glyph_info_t *info);
+static inline bool _hb_glyph_info_substituted (const hb_glyph_info_t *info);
 
 static inline bool
 _hb_glyph_info_is_default_ignorable (const hb_glyph_info_t *info)
 {
   return (info->unicode_props() & UPROPS_MASK_IGNORABLE) &&
-	 !_hb_glyph_info_ligated (info);
+	 !_hb_glyph_info_substituted (info);
 }
 static inline bool
 _hb_glyph_info_is_default_ignorable_and_not_hidden (const hb_glyph_info_t *info)
diff --git a/thirdparty/harfbuzz/src/hb-ot-math.cc b/thirdparty/harfbuzz/src/hb-ot-math.cc
index 9d8c6e735a..5781d25f2a 100644
--- a/thirdparty/harfbuzz/src/hb-ot-math.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-math.cc
@@ -56,7 +56,7 @@
  *
  * Tests whether a face has a `MATH` table.
  *
- * Return value: true if the table is found, false otherwise
+ * Return value: %true if the table is found, %false otherwise
  *
  * Since: 1.3.3
  **/
@@ -142,7 +142,7 @@ hb_ot_math_get_glyph_top_accent_attachment (hb_font_t *font,
  *
  * Tests whether the given glyph index is an extended shape in the face.
  *
- * Return value: true if the glyph is an extended shape, false otherwise
+ * Return value: %true if the glyph is an extended shape, %false otherwise
  *
  * Since: 1.3.3
  **/
diff --git a/thirdparty/harfbuzz/src/hb-ot-math.h b/thirdparty/harfbuzz/src/hb-ot-math.h
index ad864a762d..d3ffa19d85 100644
--- a/thirdparty/harfbuzz/src/hb-ot-math.h
+++ b/thirdparty/harfbuzz/src/hb-ot-math.h
@@ -24,7 +24,7 @@
  * Igalia Author(s): Frédéric Wang
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
@@ -40,18 +40,89 @@ HB_BEGIN_DECLS
  * MATH
  */
 
+/**
+ * HB_OT_TAG_MATH:
+ *
+ * OpenType [Mathematical Typesetting Table](https://docs.microsoft.com/en-us/typography/opentype/spec/math).
+ *
+ * Since: 1.3.3
+ */
 #define HB_OT_TAG_MATH HB_TAG('M','A','T','H')
 
-/* Use with hb_buffer_set_script() for math shaping. */
+/**
+ * HB_OT_MATH_SCRIPT:
+ *
+ * OpenType script tag for math shaping, for use with
+ * Use with hb_buffer_set_script().
+ *
+ * Since: 1.3.3
+ */
 #define HB_OT_MATH_SCRIPT HB_TAG('m','a','t','h')
 
 /* Types */
 
 /**
  * hb_ot_math_constant_t:
+ * @HB_OT_MATH_CONSTANT_SCRIPT_PERCENT_SCALE_DOWN: scriptPercentScaleDown
+ * @HB_OT_MATH_CONSTANT_SCRIPT_SCRIPT_PERCENT_SCALE_DOWN: scriptScriptPercentScaleDown
+ * @HB_OT_MATH_CONSTANT_DELIMITED_SUB_FORMULA_MIN_HEIGHT: delimitedSubFormulaMinHeight
+ * @HB_OT_MATH_CONSTANT_DISPLAY_OPERATOR_MIN_HEIGHT: displayOperatorMinHeight
+ * @HB_OT_MATH_CONSTANT_MATH_LEADING: mathLeading
+ * @HB_OT_MATH_CONSTANT_AXIS_HEIGHT: axisHeight
+ * @HB_OT_MATH_CONSTANT_ACCENT_BASE_HEIGHT: accentBaseHeight
+ * @HB_OT_MATH_CONSTANT_FLATTENED_ACCENT_BASE_HEIGHT: flattenedAccentBaseHeight
+ * @HB_OT_MATH_CONSTANT_SUBSCRIPT_SHIFT_DOWN: subscriptShiftDown
+ * @HB_OT_MATH_CONSTANT_SUBSCRIPT_TOP_MAX: subscriptTopMax
+ * @HB_OT_MATH_CONSTANT_SUBSCRIPT_BASELINE_DROP_MIN: subscriptBaselineDropMin
+ * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP: superscriptShiftUp
+ * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_SHIFT_UP_CRAMPED: superscriptShiftUpCramped
+ * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MIN: superscriptBottomMin
+ * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_BASELINE_DROP_MAX: superscriptBaselineDropMax
+ * @HB_OT_MATH_CONSTANT_SUB_SUPERSCRIPT_GAP_MIN: subSuperscriptGapMin
+ * @HB_OT_MATH_CONSTANT_SUPERSCRIPT_BOTTOM_MAX_WITH_SUBSCRIPT: superscriptBottomMaxWithSubscript
+ * @HB_OT_MATH_CONSTANT_SPACE_AFTER_SCRIPT: spaceAfterScript
+ * @HB_OT_MATH_CONSTANT_UPPER_LIMIT_GAP_MIN: upperLimitGapMin
+ * @HB_OT_MATH_CONSTANT_UPPER_LIMIT_BASELINE_RISE_MIN: upperLimitBaselineRiseMin
+ * @HB_OT_MATH_CONSTANT_LOWER_LIMIT_GAP_MIN: lowerLimitGapMin
+ * @HB_OT_MATH_CONSTANT_LOWER_LIMIT_BASELINE_DROP_MIN: lowerLimitBaselineDropMin
+ * @HB_OT_MATH_CONSTANT_STACK_TOP_SHIFT_UP: stackTopShiftUp
+ * @HB_OT_MATH_CONSTANT_STACK_TOP_DISPLAY_STYLE_SHIFT_UP: stackTopDisplayStyleShiftUp
+ * @HB_OT_MATH_CONSTANT_STACK_BOTTOM_SHIFT_DOWN: stackBottomShiftDown
+ * @HB_OT_MATH_CONSTANT_STACK_BOTTOM_DISPLAY_STYLE_SHIFT_DOWN: stackBottomDisplayStyleShiftDown
+ * @HB_OT_MATH_CONSTANT_STACK_GAP_MIN: stackGapMin
+ * @HB_OT_MATH_CONSTANT_STACK_DISPLAY_STYLE_GAP_MIN: stackDisplayStyleGapMin
+ * @HB_OT_MATH_CONSTANT_STRETCH_STACK_TOP_SHIFT_UP: stretchStackTopShiftUp
+ * @HB_OT_MATH_CONSTANT_STRETCH_STACK_BOTTOM_SHIFT_DOWN: stretchStackBottomShiftDown
+ * @HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_ABOVE_MIN: stretchStackGapAboveMin
+ * @HB_OT_MATH_CONSTANT_STRETCH_STACK_GAP_BELOW_MIN: stretchStackGapBelowMin
+ * @HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_SHIFT_UP: fractionNumeratorShiftUp
+ * @HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_DISPLAY_STYLE_SHIFT_UP: fractionNumeratorDisplayStyleShiftUp
+ * @HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_SHIFT_DOWN: fractionDenominatorShiftDown
+ * @HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_DISPLAY_STYLE_SHIFT_DOWN: fractionDenominatorDisplayStyleShiftDown
+ * @HB_OT_MATH_CONSTANT_FRACTION_NUMERATOR_GAP_MIN: fractionNumeratorGapMin
+ * @HB_OT_MATH_CONSTANT_FRACTION_NUM_DISPLAY_STYLE_GAP_MIN: fractionNumDisplayStyleGapMin
+ * @HB_OT_MATH_CONSTANT_FRACTION_RULE_THICKNESS: fractionRuleThickness
+ * @HB_OT_MATH_CONSTANT_FRACTION_DENOMINATOR_GAP_MIN: fractionDenominatorGapMin
+ * @HB_OT_MATH_CONSTANT_FRACTION_DENOM_DISPLAY_STYLE_GAP_MIN: fractionDenomDisplayStyleGapMin
+ * @HB_OT_MATH_CONSTANT_SKEWED_FRACTION_HORIZONTAL_GAP: skewedFractionHorizontalGap
+ * @HB_OT_MATH_CONSTANT_SKEWED_FRACTION_VERTICAL_GAP: skewedFractionVerticalGap
+ * @HB_OT_MATH_CONSTANT_OVERBAR_VERTICAL_GAP: overbarVerticalGap
+ * @HB_OT_MATH_CONSTANT_OVERBAR_RULE_THICKNESS: overbarRuleThickness
+ * @HB_OT_MATH_CONSTANT_OVERBAR_EXTRA_ASCENDER: overbarExtraAscender
+ * @HB_OT_MATH_CONSTANT_UNDERBAR_VERTICAL_GAP: underbarVerticalGap
+ * @HB_OT_MATH_CONSTANT_UNDERBAR_RULE_THICKNESS: underbarRuleThickness
+ * @HB_OT_MATH_CONSTANT_UNDERBAR_EXTRA_DESCENDER: underbarExtraDescender
+ * @HB_OT_MATH_CONSTANT_RADICAL_VERTICAL_GAP: radicalVerticalGap
+ * @HB_OT_MATH_CONSTANT_RADICAL_DISPLAY_STYLE_VERTICAL_GAP: radicalDisplayStyleVerticalGap
+ * @HB_OT_MATH_CONSTANT_RADICAL_RULE_THICKNESS: radicalRuleThickness
+ * @HB_OT_MATH_CONSTANT_RADICAL_EXTRA_ASCENDER: radicalExtraAscender
+ * @HB_OT_MATH_CONSTANT_RADICAL_KERN_BEFORE_DEGREE: radicalKernBeforeDegree
+ * @HB_OT_MATH_CONSTANT_RADICAL_KERN_AFTER_DEGREE: radicalKernAfterDegree
+ * @HB_OT_MATH_CONSTANT_RADICAL_DEGREE_BOTTOM_RAISE_PERCENT: radicalDegreeBottomRaisePercent
  *
- * The 'MATH' table constants specified at
- * https://docs.microsoft.com/en-us/typography/opentype/spec/math
+ * The 'MATH' table constants, refer to
+ * [OpenType documentation](https://docs.microsoft.com/en-us/typography/opentype/spec/math#mathconstants-table)
+ * For more explanations.
  *
  * Since: 1.3.3
  */
@@ -116,6 +187,10 @@ typedef enum {
 
 /**
  * hb_ot_math_kern_t:
+ * @HB_OT_MATH_KERN_TOP_RIGHT: The top right corner of the glyph.
+ * @HB_OT_MATH_KERN_TOP_LEFT: The top left corner of the glyph.
+ * @HB_OT_MATH_KERN_BOTTOM_RIGHT: The bottom right corner of the glyph.
+ * @HB_OT_MATH_KERN_BOTTOM_LEFT: The bottom left corner of the glyph.
  *
  * The math kerning-table types defined for the four corners
  * of a glyph.
@@ -145,6 +220,8 @@ typedef struct hb_ot_math_glyph_variant_t {
 
 /**
  * hb_ot_math_glyph_part_flags_t:
+ * @HB_OT_MATH_GLYPH_PART_FLAG_EXTENDER: This is an extender glyph part that
+ * can be repeated to reach the desired length.
  *
  * Flags for math glyph parts.
  *
diff --git a/thirdparty/harfbuzz/src/hb-ot-meta.cc b/thirdparty/harfbuzz/src/hb-ot-meta.cc
index 54a0e10f9b..35c8eb523f 100644
--- a/thirdparty/harfbuzz/src/hb-ot-meta.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-meta.cc
@@ -41,9 +41,11 @@
  * hb_ot_meta_get_entry_tags:
  * @face: a face object
  * @start_offset: iteration's start offset
- * @entries_count:(inout) (allow-none): buffer size as input, filled size as output
+ * @entries_count:(inout) (optional): buffer size as input, filled size as output
  * @entries: (out caller-allocates) (array length=entries_count): entries tags buffer
  *
+ * Fetches all available feature types.
+ *
  * Return value: Number of all available feature types.
  *
  * Since: 2.6.0
diff --git a/thirdparty/harfbuzz/src/hb-ot-meta.h b/thirdparty/harfbuzz/src/hb-ot-meta.h
index 0278d84148..7748eb4958 100644
--- a/thirdparty/harfbuzz/src/hb-ot-meta.h
+++ b/thirdparty/harfbuzz/src/hb-ot-meta.h
@@ -22,7 +22,7 @@
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
@@ -54,6 +54,7 @@ typedef enum {
   HB_OT_META_TAG_DESIGN_LANGUAGES	= HB_TAG ('d','l','n','g'),
   HB_OT_META_TAG_SUPPORTED_LANGUAGES	= HB_TAG ('s','l','n','g'),
 
+  /*< private >*/
   _HB_OT_META_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/
 } hb_ot_meta_tag_t;
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-metrics.cc b/thirdparty/harfbuzz/src/hb-ot-metrics.cc
index 3065ea2adf..72aeff82d6 100644
--- a/thirdparty/harfbuzz/src/hb-ot-metrics.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-metrics.cc
@@ -119,11 +119,11 @@ _get_gasp (hb_face_t *face, float *result, hb_ot_metrics_tag_t metrics_tag)
 
 /**
  * hb_ot_metrics_get_position:
- * @font: a #hb_font_t object.
+ * @font: an #hb_font_t object.
  * @metrics_tag: tag of metrics value you like to fetch.
  * @position: (out) (optional): result of metrics value from the font.
  *
- * It fetches metrics value corresponding to a given tag from a font.
+ * Fetches metrics value corresponding to @metrics_tag from @font.
  *
  * Returns: Whether found the requested metrics in the font.
  * Since: 2.6.0
@@ -193,10 +193,13 @@ hb_ot_metrics_get_position (hb_font_t           *font,
 #ifndef HB_NO_VAR
 /**
  * hb_ot_metrics_get_variation:
- * @font:
- * @metrics_tag:
+ * @font: an #hb_font_t object.
+ * @metrics_tag: tag of metrics value you like to fetch.
+ *
+ * Fetches metrics value corresponding to @metrics_tag from @font with the
+ * current font variation settings applied.
  *
- * Returns:
+ * Returns: The requested metric value.
  *
  * Since: 2.6.0
  **/
@@ -208,10 +211,13 @@ hb_ot_metrics_get_variation (hb_font_t *font, hb_ot_metrics_tag_t metrics_tag)
 
 /**
  * hb_ot_metrics_get_x_variation:
- * @font:
- * @metrics_tag:
+ * @font: an #hb_font_t object.
+ * @metrics_tag: tag of metrics value you like to fetch.
  *
- * Returns:
+ * Fetches horizontal metrics value corresponding to @metrics_tag from @font
+ * with the current font variation settings applied.
+ *
+ * Returns: The requested metric value.
  *
  * Since: 2.6.0
  **/
@@ -223,10 +229,13 @@ hb_ot_metrics_get_x_variation (hb_font_t *font, hb_ot_metrics_tag_t metrics_tag)
 
 /**
  * hb_ot_metrics_get_y_variation:
- * @font:
- * @metrics_tag:
+ * @font: an #hb_font_t object.
+ * @metrics_tag: tag of metrics value you like to fetch.
+ *
+ * Fetches vertical metrics value corresponding to @metrics_tag from @font with
+ * the current font variation settings applied.
  *
- * Returns:
+ * Returns: The requested metric value.
  *
  * Since: 2.6.0
  **/
diff --git a/thirdparty/harfbuzz/src/hb-ot-metrics.h b/thirdparty/harfbuzz/src/hb-ot-metrics.h
index 42c7363c03..5841fc8b0f 100644
--- a/thirdparty/harfbuzz/src/hb-ot-metrics.h
+++ b/thirdparty/harfbuzz/src/hb-ot-metrics.h
@@ -22,7 +22,7 @@
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
@@ -66,7 +66,8 @@ HB_BEGIN_DECLS
  * @HB_OT_METRICS_TAG_UNDERLINE_SIZE: underline size.
  * @HB_OT_METRICS_TAG_UNDERLINE_OFFSET: underline offset.
  *
- * From https://docs.microsoft.com/en-us/typography/opentype/spec/mvar#value-tags
+ * Metric tags corresponding to [MVAR Value
+ * Tags](https://docs.microsoft.com/en-us/typography/opentype/spec/mvar#value-tags)
  *
  * Since: 2.6.0
  **/
@@ -100,6 +101,7 @@ typedef enum {
   HB_OT_METRICS_TAG_UNDERLINE_SIZE		= HB_TAG ('u','n','d','s'),
   HB_OT_METRICS_TAG_UNDERLINE_OFFSET		= HB_TAG ('u','n','d','o'),
 
+  /*< private >*/
   _HB_OT_METRICS_TAG_MAX_VALUE = HB_TAG_MAX_SIGNED /*< skip >*/
 } hb_ot_metrics_tag_t;
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-name.cc b/thirdparty/harfbuzz/src/hb-ot-name.cc
index 10122b8c2e..4588226e6e 100644
--- a/thirdparty/harfbuzz/src/hb-ot-name.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-name.cc
@@ -46,7 +46,7 @@
 /**
  * hb_ot_name_list_names:
  * @face: font face.
- * @num_entries: (out) (allow-none): number of returned entries.
+ * @num_entries: (out) (optional): number of returned entries.
  *
  * Enumerates all available name IDs and language combinations. Returned
  * array is owned by the @face and should not be modified.  It can be
@@ -150,7 +150,7 @@ hb_ot_name_get_utf (hb_face_t       *face,
  * @face: font face.
  * @name_id: OpenType name identifier to fetch.
  * @language: language to fetch the name for.
- * @text_size: (inout) (allow-none): input size of @text buffer, and output size of
+ * @text_size: (inout) (optional): input size of @text buffer, and output size of
  *                                   text written to buffer.
  * @text: (out caller-allocates) (array length=text_size): buffer to write fetched name into.
  *
@@ -177,7 +177,7 @@ hb_ot_name_get_utf8 (hb_face_t       *face,
  * @face: font face.
  * @name_id: OpenType name identifier to fetch.
  * @language: language to fetch the name for.
- * @text_size: (inout) (allow-none): input size of @text buffer, and output size of
+ * @text_size: (inout) (optional): input size of @text buffer, and output size of
  *                                   text written to buffer.
  * @text: (out caller-allocates) (array length=text_size): buffer to write fetched name into.
  *
@@ -203,7 +203,7 @@ hb_ot_name_get_utf16 (hb_face_t       *face,
  * @face: font face.
  * @name_id: OpenType name identifier to fetch.
  * @language: language to fetch the name for.
- * @text_size: (inout) (allow-none): input size of @text buffer, and output size of
+ * @text_size: (inout) (optional): input size of @text buffer, and output size of
  *                                   text written to buffer.
  * @text: (out caller-allocates) (array length=text_size): buffer to write fetched name into.
  *
diff --git a/thirdparty/harfbuzz/src/hb-ot-name.h b/thirdparty/harfbuzz/src/hb-ot-name.h
index 6f3fcd2427..9359014c8a 100644
--- a/thirdparty/harfbuzz/src/hb-ot-name.h
+++ b/thirdparty/harfbuzz/src/hb-ot-name.h
@@ -22,7 +22,7 @@
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-os2-table.hh b/thirdparty/harfbuzz/src/hb-ot-os2-table.hh
index 7d31b712c4..8e98f87f4e 100644
--- a/thirdparty/harfbuzz/src/hb-ot-os2-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-os2-table.hh
@@ -177,15 +177,14 @@ struct OS2
     if (!c->plan->glyphs_requested->is_empty ())
     {
       hb_map_t unicode_glyphid_map;
-      
+
       OT::cmap::accelerator_t cmap;
       cmap.init (c->plan->source);
       cmap.collect_mapping (&unicodes, &unicode_glyphid_map);
       cmap.fini ();
-      
-      if (c->plan->unicodes->is_empty ()) unicodes.clear ();
-      else hb_set_set (&unicodes, c->plan->unicodes);
-  
+
+      hb_set_set (&unicodes, c->plan->unicodes);
+
       + unicode_glyphid_map.iter ()
       | hb_filter (c->plan->glyphs_requested, hb_second)
       | hb_map (hb_first)
diff --git a/thirdparty/harfbuzz/src/hb-ot-post-table.hh b/thirdparty/harfbuzz/src/hb-ot-post-table.hh
index 8586331cd4..f22d6e244d 100644
--- a/thirdparty/harfbuzz/src/hb-ot-post-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-post-table.hh
@@ -87,7 +87,6 @@ struct post
     if (unlikely (!post_prime)) return_trace (false);
 
     serialize (c->serializer);
-    if (c->serializer->in_error () || c->serializer->ran_out_of_room) return_trace (false);
 
     return_trace (true);
   }
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-arabic-win1256.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-arabic-win1256.hh
index b15e145f2f..41e3dd38ab 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-arabic-win1256.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-arabic-win1256.hh
@@ -142,7 +142,7 @@
 		OT_UARRAY(Name##Substitute, OT_LIST(ToGlyphs)) \
 	) \
 	OT_COVERAGE1(Name##Coverage, OT_LIST(FromGlyphs)) \
-	/* ASSERT_STATIC_EXPR_ZERO (len(FromGlyphs) == len(ToGlyphs)) */
+	/* static_assert_expr (len(FromGlyphs) == len(ToGlyphs)) */
 
 #define OT_SUBLOOKUP_LIGATURE_SUBST_FORMAT1(Name, FirstGlyphs, LigatureSetOffsets) \
 	OT_SUBLOOKUP(Name, 1, \
@@ -151,7 +151,7 @@
 		OT_UARRAY(Name##LigatureSetOffsetsArray, OT_LIST(LigatureSetOffsets)) \
 	) \
 	OT_COVERAGE1(Name##Coverage, OT_LIST(FirstGlyphs)) \
-	/* ASSERT_STATIC_EXPR_ZERO (len(FirstGlyphs) == len(LigatureSetOffsets)) */
+	/* static_assert_expr (len(FirstGlyphs) == len(LigatureSetOffsets)) */
 
 #define OT_LIGATURE_SET(Name, LigatureSetOffsets) \
 	OT_UARRAY(Name, OT_LIST(LigatureSetOffsets))
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-arabic.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-arabic.cc
index 1e93f0efd5..1f244f940c 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-arabic.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-arabic.cc
@@ -33,7 +33,7 @@
 
 
 /* buffer var allocations */
-#define arabic_shaping_action() complex_var_u8_0() /* arabic shaping action */
+#define arabic_shaping_action() complex_var_u8_auxiliary() /* arabic shaping action */
 
 #define HB_BUFFER_SCRATCH_FLAG_ARABIC_HAS_STCH HB_BUFFER_SCRATCH_FLAG_COMPLEX0
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-hangul.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-hangul.cc
index f5915f43ae..dbedd6af0c 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-hangul.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-hangul.cc
@@ -119,7 +119,7 @@ data_destroy_hangul (void *data)
 #define isHangulTone(u) (hb_in_range<hb_codepoint_t> ((u), 0x302Eu, 0x302Fu))
 
 /* buffer var allocations */
-#define hangul_shaping_feature() complex_var_u8_0() /* hangul jamo shaping feature */
+#define hangul_shaping_feature() complex_var_u8_auxiliary() /* hangul jamo shaping feature */
 
 static bool
 is_zero_width_char (hb_font_t *font,
@@ -205,7 +205,7 @@ preprocess_text_hangul (const hb_ot_shape_plan_t *plan HB_UNUSED,
       {
 	/* Tone mark follows a valid syllable; move it in front, unless it's zero width. */
 	buffer->unsafe_to_break_from_outbuffer (start, buffer->idx);
-	buffer->next_glyph ();
+	if (unlikely (!buffer->next_glyph ())) break;
 	if (!is_zero_width_char (font, u))
 	{
 	  buffer->merge_out_clusters (start, end + 1);
@@ -218,23 +218,25 @@ preprocess_text_hangul (const hb_ot_shape_plan_t *plan HB_UNUSED,
       else
       {
 	/* No valid syllable as base for tone mark; try to insert dotted circle. */
-      if (!(buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE) &&
-	  font->has_glyph (0x25CCu))
+	if (!(buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE) &&
+	    font->has_glyph (0x25CCu))
 	{
 	  hb_codepoint_t chars[2];
-	  if (!is_zero_width_char (font, u)) {
+	  if (!is_zero_width_char (font, u))
+	  {
 	    chars[0] = u;
 	    chars[1] = 0x25CCu;
-	  } else {
+	  } else
+	  {
 	    chars[0] = 0x25CCu;
 	    chars[1] = u;
 	  }
-	  buffer->replace_glyphs (1, 2, chars);
+	  (void) buffer->replace_glyphs (1, 2, chars);
 	}
 	else
 	{
 	  /* No dotted circle available in the font; just leave tone mark untouched. */
-	  buffer->next_glyph ();
+	  (void) buffer->next_glyph ();
 	}
       }
       start = end = buffer->out_len;
@@ -271,9 +273,7 @@ preprocess_text_hangul (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	  hb_codepoint_t s = SBase + (l - LBase) * NCount + (v - VBase) * TCount + tindex;
 	  if (font->has_glyph (s))
 	  {
-	    buffer->replace_glyphs (t ? 3 : 2, 1, &s);
-	    if (unlikely (!buffer->successful))
-	      return;
+	    (void) buffer->replace_glyphs (t ? 3 : 2, 1, &s);
 	    end = start + 1;
 	    continue;
 	  }
@@ -285,17 +285,19 @@ preprocess_text_hangul (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	 * Set jamo features on the individual glyphs, and advance past them.
 	 */
 	buffer->cur().hangul_shaping_feature() = LJMO;
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	buffer->cur().hangul_shaping_feature() = VJMO;
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (t)
 	{
 	  buffer->cur().hangul_shaping_feature() = TJMO;
-	  buffer->next_glyph ();
+	  (void) buffer->next_glyph ();
 	  end = start + 3;
 	}
 	else
 	  end = start + 2;
+	if (unlikely (!buffer->successful))
+	  break;
 	if (buffer->cluster_level == HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES)
 	  buffer->merge_out_clusters (start, end);
 	continue;
@@ -321,9 +323,7 @@ preprocess_text_hangul (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	hb_codepoint_t new_s = s + new_tindex;
 	if (font->has_glyph (new_s))
 	{
-	  buffer->replace_glyphs (2, 1, &new_s);
-	  if (unlikely (!buffer->successful))
-	    return;
+	  (void) buffer->replace_glyphs (2, 1, &new_s);
 	  end = start + 1;
 	  continue;
 	}
@@ -347,19 +347,18 @@ preprocess_text_hangul (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    (!tindex || font->has_glyph (decomposed[2])))
 	{
 	  unsigned int s_len = tindex ? 3 : 2;
-	  buffer->replace_glyphs (1, s_len, decomposed);
+	  (void) buffer->replace_glyphs (1, s_len, decomposed);
 
 	  /* If we decomposed an LV because of a non-combining T following,
 	   * we want to include this T in the syllable.
 	   */
 	  if (has_glyph && !tindex)
 	  {
-	    buffer->next_glyph ();
+	    (void) buffer->next_glyph ();
 	    s_len++;
 	  }
-
 	  if (unlikely (!buffer->successful))
-	    return;
+	    break;
 
 	  /* We decomposed S: apply jamo features to the individual glyphs
 	   * that are now in buffer->out_info.
@@ -383,17 +382,15 @@ preprocess_text_hangul (const hb_ot_shape_plan_t *plan HB_UNUSED,
 
       if (has_glyph)
       {
-	/* We didn't decompose the S, so just advance past it. */
+	/* We didn't decompose the S, so just advance past it and fall through. */
 	end = start + 1;
-	buffer->next_glyph ();
-	continue;
       }
     }
 
     /* Didn't find a recognizable syllable, so we leave end <= start;
      * this will prevent tone-mark reordering happening.
      */
-    buffer->next_glyph ();
+    (void) buffer->next_glyph ();
   }
   buffer->swap_buffers ();
 }
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic-machine.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic-machine.hh
index 670b6bf486..74bf3ca0fa 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic-machine.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic-machine.hh
@@ -31,8 +31,37 @@
 
 #include "hb.hh"
 
+enum indic_syllable_type_t {
+  indic_consonant_syllable,
+  indic_vowel_syllable,
+  indic_standalone_cluster,
+  indic_symbol_cluster,
+  indic_broken_cluster,
+  indic_non_indic_cluster,
+};
+
 
-#line 36 "hb-ot-shape-complex-indic-machine.hh"
+#line 45 "hb-ot-shape-complex-indic-machine.hh"
+#define indic_syllable_machine_ex_A 10u
+#define indic_syllable_machine_ex_C 1u
+#define indic_syllable_machine_ex_CM 17u
+#define indic_syllable_machine_ex_CS 19u
+#define indic_syllable_machine_ex_DOTTEDCIRCLE 12u
+#define indic_syllable_machine_ex_H 4u
+#define indic_syllable_machine_ex_M 7u
+#define indic_syllable_machine_ex_N 3u
+#define indic_syllable_machine_ex_PLACEHOLDER 11u
+#define indic_syllable_machine_ex_RS 13u
+#define indic_syllable_machine_ex_Ra 16u
+#define indic_syllable_machine_ex_Repha 15u
+#define indic_syllable_machine_ex_SM 8u
+#define indic_syllable_machine_ex_Symbol 18u
+#define indic_syllable_machine_ex_V 2u
+#define indic_syllable_machine_ex_ZWJ 6u
+#define indic_syllable_machine_ex_ZWNJ 5u
+
+
+#line 65 "hb-ot-shape-complex-indic-machine.hh"
 static const unsigned char _indic_syllable_machine_trans_keys[] = {
 	8u, 8u, 4u, 8u, 5u, 7u, 5u, 8u, 4u, 8u, 6u, 6u, 16u, 16u, 4u, 8u, 
 	4u, 13u, 4u, 8u, 8u, 8u, 5u, 7u, 5u, 8u, 4u, 8u, 6u, 6u, 16u, 16u, 
@@ -384,18 +413,18 @@ static const int indic_syllable_machine_error = -1;
 static const int indic_syllable_machine_en_main = 39;
 
 
-#line 36 "hb-ot-shape-complex-indic-machine.rl"
+#line 46 "hb-ot-shape-complex-indic-machine.rl"
 
 
 
-#line 93 "hb-ot-shape-complex-indic-machine.rl"
+#line 102 "hb-ot-shape-complex-indic-machine.rl"
 
 
 #define found_syllable(syllable_type) \
   HB_STMT_START { \
     if (0) fprintf (stderr, "syllable %d..%d %s\n", ts, te, #syllable_type); \
     for (unsigned int i = ts; i < te; i++) \
-      info[i].syllable() = (syllable_serial << 4) | indic_##syllable_type; \
+      info[i].syllable() = (syllable_serial << 4) | syllable_type; \
     syllable_serial++; \
     if (unlikely (syllable_serial == 16)) syllable_serial = 1; \
   } HB_STMT_END
@@ -407,7 +436,7 @@ find_syllables_indic (hb_buffer_t *buffer)
   int cs;
   hb_glyph_info_t *info = buffer->info;
   
-#line 411 "hb-ot-shape-complex-indic-machine.hh"
+#line 440 "hb-ot-shape-complex-indic-machine.hh"
 	{
 	cs = indic_syllable_machine_start;
 	ts = 0;
@@ -415,7 +444,7 @@ find_syllables_indic (hb_buffer_t *buffer)
 	act = 0;
 	}
 
-#line 113 "hb-ot-shape-complex-indic-machine.rl"
+#line 122 "hb-ot-shape-complex-indic-machine.rl"
 
 
   p = 0;
@@ -423,7 +452,7 @@ find_syllables_indic (hb_buffer_t *buffer)
 
   unsigned int syllable_serial = 1;
   
-#line 427 "hb-ot-shape-complex-indic-machine.hh"
+#line 456 "hb-ot-shape-complex-indic-machine.hh"
 	{
 	int _slen;
 	int _trans;
@@ -437,7 +466,7 @@ _resume:
 #line 1 "NONE"
 	{ts = p;}
 	break;
-#line 441 "hb-ot-shape-complex-indic-machine.hh"
+#line 470 "hb-ot-shape-complex-indic-machine.hh"
 	}
 
 	_keys = _indic_syllable_machine_trans_keys + (cs<<1);
@@ -460,64 +489,64 @@ _eof_trans:
 	{te = p+1;}
 	break;
 	case 11:
-#line 89 "hb-ot-shape-complex-indic-machine.rl"
-	{te = p+1;{ found_syllable (non_indic_cluster); }}
+#line 98 "hb-ot-shape-complex-indic-machine.rl"
+	{te = p+1;{ found_syllable (indic_non_indic_cluster); }}
 	break;
 	case 13:
-#line 84 "hb-ot-shape-complex-indic-machine.rl"
-	{te = p;p--;{ found_syllable (consonant_syllable); }}
+#line 93 "hb-ot-shape-complex-indic-machine.rl"
+	{te = p;p--;{ found_syllable (indic_consonant_syllable); }}
 	break;
 	case 14:
-#line 85 "hb-ot-shape-complex-indic-machine.rl"
-	{te = p;p--;{ found_syllable (vowel_syllable); }}
+#line 94 "hb-ot-shape-complex-indic-machine.rl"
+	{te = p;p--;{ found_syllable (indic_vowel_syllable); }}
 	break;
 	case 17:
-#line 86 "hb-ot-shape-complex-indic-machine.rl"
-	{te = p;p--;{ found_syllable (standalone_cluster); }}
+#line 95 "hb-ot-shape-complex-indic-machine.rl"
+	{te = p;p--;{ found_syllable (indic_standalone_cluster); }}
 	break;
 	case 19:
-#line 87 "hb-ot-shape-complex-indic-machine.rl"
-	{te = p;p--;{ found_syllable (symbol_cluster); }}
+#line 96 "hb-ot-shape-complex-indic-machine.rl"
+	{te = p;p--;{ found_syllable (indic_symbol_cluster); }}
 	break;
 	case 15:
-#line 88 "hb-ot-shape-complex-indic-machine.rl"
-	{te = p;p--;{ found_syllable (broken_cluster); }}
+#line 97 "hb-ot-shape-complex-indic-machine.rl"
+	{te = p;p--;{ found_syllable (indic_broken_cluster); }}
 	break;
 	case 16:
-#line 89 "hb-ot-shape-complex-indic-machine.rl"
-	{te = p;p--;{ found_syllable (non_indic_cluster); }}
+#line 98 "hb-ot-shape-complex-indic-machine.rl"
+	{te = p;p--;{ found_syllable (indic_non_indic_cluster); }}
 	break;
 	case 1:
-#line 84 "hb-ot-shape-complex-indic-machine.rl"
-	{{p = ((te))-1;}{ found_syllable (consonant_syllable); }}
+#line 93 "hb-ot-shape-complex-indic-machine.rl"
+	{{p = ((te))-1;}{ found_syllable (indic_consonant_syllable); }}
 	break;
 	case 3:
-#line 85 "hb-ot-shape-complex-indic-machine.rl"
-	{{p = ((te))-1;}{ found_syllable (vowel_syllable); }}
+#line 94 "hb-ot-shape-complex-indic-machine.rl"
+	{{p = ((te))-1;}{ found_syllable (indic_vowel_syllable); }}
 	break;
 	case 7:
-#line 86 "hb-ot-shape-complex-indic-machine.rl"
-	{{p = ((te))-1;}{ found_syllable (standalone_cluster); }}
+#line 95 "hb-ot-shape-complex-indic-machine.rl"
+	{{p = ((te))-1;}{ found_syllable (indic_standalone_cluster); }}
 	break;
 	case 8:
-#line 87 "hb-ot-shape-complex-indic-machine.rl"
-	{{p = ((te))-1;}{ found_syllable (symbol_cluster); }}
+#line 96 "hb-ot-shape-complex-indic-machine.rl"
+	{{p = ((te))-1;}{ found_syllable (indic_symbol_cluster); }}
 	break;
 	case 4:
-#line 88 "hb-ot-shape-complex-indic-machine.rl"
-	{{p = ((te))-1;}{ found_syllable (broken_cluster); }}
+#line 97 "hb-ot-shape-complex-indic-machine.rl"
+	{{p = ((te))-1;}{ found_syllable (indic_broken_cluster); }}
 	break;
 	case 6:
 #line 1 "NONE"
 	{	switch( act ) {
 	case 1:
-	{{p = ((te))-1;} found_syllable (consonant_syllable); }
+	{{p = ((te))-1;} found_syllable (indic_consonant_syllable); }
 	break;
 	case 5:
-	{{p = ((te))-1;} found_syllable (broken_cluster); }
+	{{p = ((te))-1;} found_syllable (indic_broken_cluster); }
 	break;
 	case 6:
-	{{p = ((te))-1;} found_syllable (non_indic_cluster); }
+	{{p = ((te))-1;} found_syllable (indic_non_indic_cluster); }
 	break;
 	}
 	}
@@ -525,22 +554,22 @@ _eof_trans:
 	case 18:
 #line 1 "NONE"
 	{te = p+1;}
-#line 84 "hb-ot-shape-complex-indic-machine.rl"
+#line 93 "hb-ot-shape-complex-indic-machine.rl"
 	{act = 1;}
 	break;
 	case 5:
 #line 1 "NONE"
 	{te = p+1;}
-#line 88 "hb-ot-shape-complex-indic-machine.rl"
+#line 97 "hb-ot-shape-complex-indic-machine.rl"
 	{act = 5;}
 	break;
 	case 12:
 #line 1 "NONE"
 	{te = p+1;}
-#line 89 "hb-ot-shape-complex-indic-machine.rl"
+#line 98 "hb-ot-shape-complex-indic-machine.rl"
 	{act = 6;}
 	break;
-#line 544 "hb-ot-shape-complex-indic-machine.hh"
+#line 573 "hb-ot-shape-complex-indic-machine.hh"
 	}
 
 _again:
@@ -549,7 +578,7 @@ _again:
 #line 1 "NONE"
 	{ts = 0;}
 	break;
-#line 553 "hb-ot-shape-complex-indic-machine.hh"
+#line 582 "hb-ot-shape-complex-indic-machine.hh"
 	}
 
 	if ( ++p != pe )
@@ -565,7 +594,7 @@ _again:
 
 	}
 
-#line 121 "hb-ot-shape-complex-indic-machine.rl"
+#line 130 "hb-ot-shape-complex-indic-machine.rl"
 
 }
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic-table.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic-table.cc
index a150fd2486..dd204b23c1 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic-table.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic-table.cc
@@ -82,7 +82,7 @@
 #define _(S,M) INDIC_COMBINE_CATEGORIES (ISC_##S, IMC_##M)
 
 
-static const INDIC_TABLE_ELEMENT_TYPE indic_table[] = {
+static const uint16_t indic_table[] = {
 
 
 #define indic_offset_0x0028u 0
@@ -404,7 +404,7 @@ static const INDIC_TABLE_ELEMENT_TYPE indic_table[] = {
 
 }; /* Table items: 1792; occupancy: 70% */
 
-INDIC_TABLE_ELEMENT_TYPE
+uint16_t
 hb_indic_get_categories (hb_codepoint_t u)
 {
   switch (u >> 12)
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc
index 652ef47040..a4f2d9a847 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.cc
@@ -29,6 +29,7 @@
 #ifndef HB_NO_OT_SHAPE
 
 #include "hb-ot-shape-complex-indic.hh"
+#include "hb-ot-shape-complex-indic-machine.hh"
 #include "hb-ot-shape-complex-vowel-constraints.hh"
 #include "hb-ot-layout.hh"
 
@@ -337,19 +338,6 @@ consonant_position_from_face (const indic_shape_plan_t *indic_plan,
   return POS_BASE_C;
 }
 
-
-enum indic_syllable_type_t {
-  indic_consonant_syllable,
-  indic_vowel_syllable,
-  indic_standalone_cluster,
-  indic_symbol_cluster,
-  indic_broken_cluster,
-  indic_non_indic_cluster,
-};
-
-#include "hb-ot-shape-complex-indic-machine.hh"
-
-
 static void
 setup_masks_indic (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		   hb_buffer_t              *buffer,
@@ -764,7 +752,28 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
      * We could use buffer->sort() for this, if there was no special
      * reordering of pre-base stuff happening later...
      * We don't want to merge_clusters all of that, which buffer->sort()
-     * would.
+     * would.  Here's a concrete example:
+     *
+     * Assume there's a pre-base consonant and explicit Halant before base,
+     * followed by a prebase-reordering (left) Matra:
+     *
+     *   C,H,ZWNJ,B,M
+     *
+     * At this point in reordering we would have:
+     *
+     *   M,C,H,ZWNJ,B
+     *
+     * whereas in final reordering we will bring the Matra closer to Base:
+     *
+     *   C,H,ZWNJ,M,B
+     *
+     * That's why we don't want to merge-clusters anything before the Base
+     * at this point.  But if something moved from after Base to before it,
+     * we should merge clusters from base to them.  In final-reordering, we
+     * only move things around before base, and merge-clusters up to base.
+     * These two merge-clusters from the two sides of base will interlock
+     * to merge things correctly.  See:
+     * https://github.com/harfbuzz/harfbuzz/issues/2272
      */
     if (indic_plan->is_old_spec || end - start > 127)
       buffer->merge_clusters (base, end);
@@ -774,17 +783,18 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
       for (unsigned int i = base; i < end; i++)
 	if (info[i].syllable() != 255)
 	{
+	  unsigned int min = i;
 	  unsigned int max = i;
 	  unsigned int j = start + info[i].syllable();
 	  while (j != i)
 	  {
+	    min = hb_min (min, j);
 	    max = hb_max (max, j);
 	    unsigned int next = start + info[j].syllable();
 	    info[j].syllable() = 255; /* So we don't process j later again. */
 	    j = next;
 	  }
-	  if (i != max)
-	    buffer->merge_clusters (i, max + 1);
+	  buffer->merge_clusters (hb_max (base, min), max + 1);
 	}
     }
 
@@ -938,69 +948,6 @@ initial_reordering_syllable_indic (const hb_ot_shape_plan_t *plan,
   }
 }
 
-static inline void
-insert_dotted_circles_indic (const hb_ot_shape_plan_t *plan HB_UNUSED,
-			     hb_font_t *font,
-			     hb_buffer_t *buffer)
-{
-  if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
-    return;
-
-  /* Note: This loop is extra overhead, but should not be measurable.
-   * TODO Use a buffer scratch flag to remove the loop. */
-  bool has_broken_syllables = false;
-  unsigned int count = buffer->len;
-  hb_glyph_info_t *info = buffer->info;
-  for (unsigned int i = 0; i < count; i++)
-    if ((info[i].syllable() & 0x0F) == indic_broken_cluster)
-    {
-      has_broken_syllables = true;
-      break;
-    }
-  if (likely (!has_broken_syllables))
-    return;
-
-
-  hb_codepoint_t dottedcircle_glyph;
-  if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
-    return;
-
-  hb_glyph_info_t dottedcircle = {0};
-  dottedcircle.codepoint = 0x25CCu;
-  set_indic_properties (dottedcircle);
-  dottedcircle.codepoint = dottedcircle_glyph;
-
-  buffer->clear_output ();
-
-  buffer->idx = 0;
-  unsigned int last_syllable = 0;
-  while (buffer->idx < buffer->len && buffer->successful)
-  {
-    unsigned int syllable = buffer->cur().syllable();
-    indic_syllable_type_t syllable_type = (indic_syllable_type_t) (syllable & 0x0F);
-    if (unlikely (last_syllable != syllable && syllable_type == indic_broken_cluster))
-    {
-      last_syllable = syllable;
-
-      hb_glyph_info_t ginfo = dottedcircle;
-      ginfo.cluster = buffer->cur().cluster;
-      ginfo.mask = buffer->cur().mask;
-      ginfo.syllable() = buffer->cur().syllable();
-
-      /* Insert dottedcircle after possible Repha. */
-      while (buffer->idx < buffer->len && buffer->successful &&
-	     last_syllable == buffer->cur().syllable() &&
-	     buffer->cur().indic_category() == OT_Repha)
-	buffer->next_glyph ();
-
-      buffer->output_info (ginfo);
-    }
-    else
-      buffer->next_glyph ();
-  }
-  buffer->swap_buffers ();
-}
-
 static void
 initial_reordering_indic (const hb_ot_shape_plan_t *plan,
 			  hb_font_t *font,
@@ -1008,11 +955,16 @@ initial_reordering_indic (const hb_ot_shape_plan_t *plan,
 {
   if (!buffer->message (font, "start reordering indic initial"))
     return;
+
   update_consonant_positions_indic (plan, font, buffer);
-  insert_dotted_circles_indic (plan, font, buffer);
+  hb_syllabic_insert_dotted_circles (font, buffer,
+				     indic_broken_cluster,
+				     OT_DOTTEDCIRCLE,
+				     OT_Repha);
 
   foreach_syllable (buffer, start, end)
     initial_reordering_syllable_indic (plan, font->face, buffer, start, end);
+
   (void) buffer->message (font, "end reordering indic initial");
 }
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh
index 41bd8bd6cc..dcb28a4e84 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh
@@ -29,16 +29,14 @@
 
 #include "hb.hh"
 
-#include "hb-ot-shape-complex.hh"
+#include "hb-ot-shape-complex-syllabic.hh"
 
 
 /* buffer var allocations */
-#define indic_category() complex_var_u8_0() /* indic_category_t */
-#define indic_position() complex_var_u8_1() /* indic_position_t */
+#define indic_category() complex_var_u8_category() /* indic_category_t */
+#define indic_position() complex_var_u8_auxiliary() /* indic_position_t */
 
 
-#define INDIC_TABLE_ELEMENT_TYPE uint16_t
-
 /* Cateories used in the OpenType spec:
  * https://docs.microsoft.com/en-us/typography/script-development/devanagari
  */
@@ -177,7 +175,7 @@ enum indic_matra_category_t {
 
 #define INDIC_COMBINE_CATEGORIES(S,M) \
   ( \
-    ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \
+    static_assert_expr (S < 255 && M < 255) + \
     ( S | \
      ( \
       ( \
@@ -194,7 +192,7 @@ enum indic_matra_category_t {
     ) \
    )
 
-HB_INTERNAL INDIC_TABLE_ELEMENT_TYPE
+HB_INTERNAL uint16_t
 hb_indic_get_categories (hb_codepoint_t u);
 
 
@@ -307,17 +305,12 @@ static const hb_codepoint_t ra_chars[] = {
   0x0D30u, /* Malayalam */	/* No Reph, Logical Repha */
 
   0x0DBBu, /* Sinhala */	/* Reph formed only with ZWJ */
-
-  0x179Au, /* Khmer */
 };
 
 static inline bool
 is_ra (hb_codepoint_t u)
 {
-  for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++)
-    if (u == ra_chars[i])
-      return true;
-  return false;
+  return hb_array (ra_chars).lfind (u);
 }
 
 static inline void
@@ -325,7 +318,7 @@ set_indic_properties (hb_glyph_info_t &info)
 {
   hb_codepoint_t u = info.codepoint;
   unsigned int type = hb_indic_get_categories (u);
-  indic_category_t cat = (indic_category_t) (type & 0x7Fu);
+  indic_category_t cat = (indic_category_t) (type & 0xFFu);
   indic_position_t pos = (indic_position_t) (type >> 8);
 
 
@@ -370,6 +363,7 @@ set_indic_properties (hb_glyph_info_t &info)
   else if (unlikely (u == 0x1133Bu || u == 0x1133Cu)) cat = OT_N;
 
   else if (unlikely (u == 0x0AFBu)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/552 */
+  else if (unlikely (u == 0x0B55u)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/2849 */
 
   else if (unlikely (u == 0x0980u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/issues/538 */
   else if (unlikely (u == 0x09FCu)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/1613 */
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer-machine.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer-machine.hh
index a040318d34..82ab186a41 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer-machine.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer-machine.hh
@@ -1,211 +1,179 @@
-
 #line 1 "hb-ot-shape-complex-khmer-machine.rl"
 /*
- * Copyright © 2011,2012  Google, Inc.
- *
- *  This is part of HarfBuzz, a text shaping library.
- *
- * Permission is hereby granted, without written agreement and without
- * license or royalty fees, to use, copy, modify, and distribute this
- * software and its documentation for any purpose, provided that the
- * above copyright notice and the following two paragraphs appear in
- * all copies of this software.
- *
- * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
- * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
- * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
- * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
- * DAMAGE.
- *
- * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
- * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
- * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
- * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- *
- * Google Author(s): Behdad Esfahbod
- */
+* Copyright © 2011,2012  Google, Inc.
+*
+*  This is part of HarfBuzz, a text shaping library.
+*
+* Permission is hereby granted, without written agreement and without
+* license or royalty fees, to use, copy, modify, and distribute this
+* software and its documentation for any purpose, provided that the
+* above copyright notice and the following two paragraphs appear in
+* all copies of this software.
+*
+* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+* DAMAGE.
+*
+* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+* FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+*
+* Google Author(s): Behdad Esfahbod
+*/
 
 #ifndef HB_OT_SHAPE_COMPLEX_KHMER_MACHINE_HH
 #define HB_OT_SHAPE_COMPLEX_KHMER_MACHINE_HH
 
 #include "hb.hh"
 
+enum khmer_syllable_type_t {
+	khmer_consonant_syllable,
+	khmer_broken_cluster,
+	khmer_non_khmer_cluster,
+};
+
 
-#line 36 "hb-ot-shape-complex-khmer-machine.hh"
+#line 41 "hb-ot-shape-complex-khmer-machine.hh"
+#define khmer_syllable_machine_ex_C 1u
+#define khmer_syllable_machine_ex_Coeng 14u
+#define khmer_syllable_machine_ex_DOTTEDCIRCLE 12u
+#define khmer_syllable_machine_ex_PLACEHOLDER 11u
+#define khmer_syllable_machine_ex_Ra 16u
+#define khmer_syllable_machine_ex_Robatic 20u
+#define khmer_syllable_machine_ex_V 2u
+#define khmer_syllable_machine_ex_VAbv 26u
+#define khmer_syllable_machine_ex_VBlw 27u
+#define khmer_syllable_machine_ex_VPre 28u
+#define khmer_syllable_machine_ex_VPst 29u
+#define khmer_syllable_machine_ex_Xgroup 21u
+#define khmer_syllable_machine_ex_Ygroup 22u
+#define khmer_syllable_machine_ex_ZWJ 6u
+#define khmer_syllable_machine_ex_ZWNJ 5u
+
+
+#line 59 "hb-ot-shape-complex-khmer-machine.hh"
 static const unsigned char _khmer_syllable_machine_trans_keys[] = {
-	5u, 26u, 5u, 21u, 5u, 26u, 5u, 21u, 1u, 16u, 5u, 21u, 5u, 26u, 5u, 21u, 
-	5u, 26u, 5u, 21u, 5u, 21u, 5u, 26u, 5u, 21u, 1u, 16u, 5u, 21u, 5u, 26u, 
-	5u, 21u, 5u, 26u, 5u, 21u, 5u, 26u, 1u, 29u, 5u, 29u, 5u, 29u, 5u, 29u, 
-	22u, 22u, 5u, 22u, 5u, 29u, 5u, 29u, 5u, 29u, 1u, 16u, 5u, 26u, 5u, 29u, 
-	5u, 29u, 22u, 22u, 5u, 22u, 5u, 29u, 5u, 29u, 1u, 16u, 5u, 29u, 5u, 29u, 
-	0
+	2u, 8u, 2u, 6u, 2u, 8u, 2u, 6u,
+	0u, 0u, 2u, 6u, 2u, 8u, 2u, 6u,
+	2u, 8u, 2u, 6u, 2u, 6u, 2u, 8u,
+	2u, 6u, 0u, 0u, 2u, 6u, 2u, 8u,
+	2u, 6u, 2u, 8u, 2u, 6u, 2u, 8u,
+	0u, 11u, 2u, 11u, 2u, 11u, 2u, 11u,
+	7u, 7u, 2u, 7u, 2u, 11u, 2u, 11u,
+	2u, 11u, 0u, 0u, 2u, 8u, 2u, 11u,
+	2u, 11u, 7u, 7u, 2u, 7u, 2u, 11u,
+	2u, 11u, 0u, 0u, 2u, 11u, 2u, 11u,
+	0u
 };
 
-static const char _khmer_syllable_machine_key_spans[] = {
-	22, 17, 22, 17, 16, 17, 22, 17, 
-	22, 17, 17, 22, 17, 16, 17, 22, 
-	17, 22, 17, 22, 29, 25, 25, 25, 
-	1, 18, 25, 25, 25, 16, 22, 25, 
-	25, 1, 18, 25, 25, 16, 25, 25
+static const signed char _khmer_syllable_machine_char_class[] = {
+	0, 0, 1, 1, 2, 2, 1, 1,
+	1, 1, 3, 3, 1, 4, 1, 0,
+	1, 1, 1, 5, 6, 7, 1, 1,
+	1, 8, 9, 10, 11, 0
 };
 
 static const short _khmer_syllable_machine_index_offsets[] = {
-	0, 23, 41, 64, 82, 99, 117, 140, 
-	158, 181, 199, 217, 240, 258, 275, 293, 
-	316, 334, 357, 375, 398, 428, 454, 480, 
-	506, 508, 527, 553, 579, 605, 622, 645, 
-	671, 697, 699, 718, 744, 770, 787, 813
+	0, 7, 12, 19, 24, 25, 30, 37,
+	42, 49, 54, 59, 66, 71, 72, 77,
+	84, 89, 96, 101, 108, 120, 130, 140,
+	150, 151, 157, 167, 177, 187, 188, 195,
+	205, 215, 216, 222, 232, 242, 243, 253,
+	0
 };
 
-static const char _khmer_syllable_machine_indicies[] = {
-	1, 1, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 2, 
-	3, 0, 0, 0, 0, 4, 0, 1, 
-	1, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 3, 
-	0, 1, 1, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 3, 0, 0, 0, 0, 4, 0, 
-	5, 5, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	4, 0, 6, 6, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 6, 0, 7, 7, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 8, 0, 9, 9, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 10, 0, 0, 
-	0, 0, 4, 0, 9, 9, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 10, 0, 11, 11, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 12, 0, 
-	0, 0, 0, 4, 0, 11, 11, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 12, 0, 14, 
-	14, 13, 13, 13, 13, 13, 13, 13, 
-	13, 13, 13, 13, 13, 13, 13, 15, 
-	13, 14, 14, 16, 16, 16, 16, 16, 
-	16, 16, 16, 16, 16, 16, 16, 16, 
-	16, 15, 16, 16, 16, 16, 17, 16, 
-	18, 18, 16, 16, 16, 16, 16, 16, 
-	16, 16, 16, 16, 16, 16, 16, 16, 
-	17, 16, 19, 19, 16, 16, 16, 16, 
-	16, 16, 16, 16, 16, 16, 16, 16, 
-	16, 19, 16, 20, 20, 16, 16, 16, 
-	16, 16, 16, 16, 16, 16, 16, 16, 
-	16, 16, 16, 21, 16, 22, 22, 16, 
-	16, 16, 16, 16, 16, 16, 16, 16, 
-	16, 16, 16, 16, 16, 23, 16, 16, 
-	16, 16, 17, 16, 22, 22, 16, 16, 
-	16, 16, 16, 16, 16, 16, 16, 16, 
-	16, 16, 16, 16, 23, 16, 24, 24, 
-	16, 16, 16, 16, 16, 16, 16, 16, 
-	16, 16, 16, 16, 16, 16, 25, 16, 
-	16, 16, 16, 17, 16, 24, 24, 16, 
-	16, 16, 16, 16, 16, 16, 16, 16, 
-	16, 16, 16, 16, 16, 25, 16, 14, 
-	14, 16, 16, 16, 16, 16, 16, 16, 
-	16, 16, 16, 16, 16, 16, 26, 15, 
-	16, 16, 16, 16, 17, 16, 28, 28, 
-	27, 27, 29, 29, 27, 27, 27, 27, 
-	2, 2, 27, 30, 27, 28, 27, 27, 
-	27, 27, 15, 19, 27, 27, 27, 17, 
-	23, 25, 21, 27, 32, 32, 31, 31, 
-	31, 31, 31, 31, 31, 33, 31, 31, 
-	31, 31, 31, 2, 3, 6, 31, 31, 
-	31, 4, 10, 12, 8, 31, 34, 34, 
-	31, 31, 31, 31, 31, 31, 31, 35, 
-	31, 31, 31, 31, 31, 31, 3, 6, 
-	31, 31, 31, 4, 10, 12, 8, 31, 
-	5, 5, 31, 31, 31, 31, 31, 31, 
-	31, 35, 31, 31, 31, 31, 31, 31, 
-	4, 6, 31, 31, 31, 31, 31, 31, 
-	8, 31, 6, 31, 7, 7, 31, 31, 
-	31, 31, 31, 31, 31, 35, 31, 31, 
-	31, 31, 31, 31, 8, 6, 31, 36, 
-	36, 31, 31, 31, 31, 31, 31, 31, 
-	35, 31, 31, 31, 31, 31, 31, 10, 
-	6, 31, 31, 31, 4, 31, 31, 8, 
-	31, 37, 37, 31, 31, 31, 31, 31, 
-	31, 31, 35, 31, 31, 31, 31, 31, 
-	31, 12, 6, 31, 31, 31, 4, 10, 
-	31, 8, 31, 34, 34, 31, 31, 31, 
-	31, 31, 31, 31, 33, 31, 31, 31, 
-	31, 31, 31, 3, 6, 31, 31, 31, 
-	4, 10, 12, 8, 31, 28, 28, 31, 
-	31, 31, 31, 31, 31, 31, 31, 31, 
-	31, 31, 31, 31, 28, 31, 14, 14, 
-	38, 38, 38, 38, 38, 38, 38, 38, 
-	38, 38, 38, 38, 38, 38, 15, 38, 
-	38, 38, 38, 17, 38, 40, 40, 39, 
-	39, 39, 39, 39, 39, 39, 41, 39, 
-	39, 39, 39, 39, 39, 15, 19, 39, 
-	39, 39, 17, 23, 25, 21, 39, 18, 
-	18, 39, 39, 39, 39, 39, 39, 39, 
-	41, 39, 39, 39, 39, 39, 39, 17, 
-	19, 39, 39, 39, 39, 39, 39, 21, 
-	39, 19, 39, 20, 20, 39, 39, 39, 
-	39, 39, 39, 39, 41, 39, 39, 39, 
-	39, 39, 39, 21, 19, 39, 42, 42, 
-	39, 39, 39, 39, 39, 39, 39, 41, 
-	39, 39, 39, 39, 39, 39, 23, 19, 
-	39, 39, 39, 17, 39, 39, 21, 39, 
-	43, 43, 39, 39, 39, 39, 39, 39, 
-	39, 41, 39, 39, 39, 39, 39, 39, 
-	25, 19, 39, 39, 39, 17, 23, 39, 
-	21, 39, 44, 44, 39, 39, 39, 39, 
-	39, 39, 39, 39, 39, 39, 39, 39, 
-	39, 44, 39, 45, 45, 39, 39, 39, 
-	39, 39, 39, 39, 30, 39, 39, 39, 
-	39, 39, 26, 15, 19, 39, 39, 39, 
-	17, 23, 25, 21, 39, 40, 40, 39, 
-	39, 39, 39, 39, 39, 39, 30, 39, 
-	39, 39, 39, 39, 39, 15, 19, 39, 
-	39, 39, 17, 23, 25, 21, 39, 0
+static const signed char _khmer_syllable_machine_indicies[] = {
+	1, 0, 0, 2, 3, 0, 4, 1,
+	0, 0, 0, 3, 1, 0, 0, 0,
+	3, 0, 4, 5, 0, 0, 0, 4,
+	6, 7, 0, 0, 0, 8, 9, 0,
+	0, 0, 10, 0, 4, 9, 0, 0,
+	0, 10, 11, 0, 0, 0, 12, 0,
+	4, 11, 0, 0, 0, 12, 14, 13,
+	13, 13, 15, 14, 16, 16, 16, 15,
+	16, 17, 18, 16, 16, 16, 17, 19,
+	20, 16, 16, 16, 21, 22, 16, 16,
+	16, 23, 16, 17, 22, 16, 16, 16,
+	23, 24, 16, 16, 16, 25, 16, 17,
+	24, 16, 16, 16, 25, 14, 16, 16,
+	26, 15, 16, 17, 29, 28, 30, 2,
+	31, 28, 15, 19, 17, 23, 25, 21,
+	33, 32, 34, 2, 3, 6, 4, 10,
+	12, 8, 35, 32, 36, 32, 3, 6,
+	4, 10, 12, 8, 5, 32, 36, 32,
+	4, 6, 32, 32, 32, 8, 6, 7,
+	32, 36, 32, 8, 6, 37, 32, 36,
+	32, 10, 6, 4, 32, 32, 8, 38,
+	32, 36, 32, 12, 6, 4, 10, 32,
+	8, 35, 32, 34, 32, 3, 6, 4,
+	10, 12, 8, 29, 14, 39, 39, 39,
+	15, 39, 17, 41, 40, 42, 40, 15,
+	19, 17, 23, 25, 21, 18, 40, 42,
+	40, 17, 19, 40, 40, 40, 21, 19,
+	20, 40, 42, 40, 21, 19, 43, 40,
+	42, 40, 23, 19, 17, 40, 40, 21,
+	44, 40, 42, 40, 25, 19, 17, 23,
+	40, 21, 45, 46, 40, 31, 26, 15,
+	19, 17, 23, 25, 21, 41, 40, 31,
+	40, 15, 19, 17, 23, 25, 21, 0
 };
 
-static const char _khmer_syllable_machine_trans_targs[] = {
-	20, 1, 28, 22, 23, 3, 24, 5, 
-	25, 7, 26, 9, 27, 20, 10, 31, 
-	20, 32, 12, 33, 14, 34, 16, 35, 
-	18, 36, 39, 20, 21, 30, 37, 20, 
-	0, 29, 2, 4, 6, 8, 20, 20, 
-	11, 13, 15, 17, 38, 19
+static const signed char _khmer_syllable_machine_index_defaults[] = {
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 13, 16, 16, 16, 16, 16,
+	16, 16, 16, 16, 28, 32, 32, 32,
+	32, 32, 32, 32, 32, 32, 39, 40,
+	40, 40, 40, 40, 40, 40, 40, 40,
+	0
 };
 
-static const char _khmer_syllable_machine_trans_actions[] = {
-	1, 0, 2, 2, 2, 0, 0, 0, 
-	2, 0, 2, 0, 2, 3, 0, 4, 
-	5, 2, 0, 0, 0, 2, 0, 2, 
-	0, 2, 4, 8, 2, 9, 0, 10, 
-	0, 0, 0, 0, 0, 0, 11, 12, 
-	0, 0, 0, 0, 4, 0
+static const signed char _khmer_syllable_machine_cond_targs[] = {
+	20, 1, 28, 22, 23, 3, 24, 5,
+	25, 7, 26, 9, 27, 20, 10, 31,
+	20, 32, 12, 33, 14, 34, 16, 35,
+	18, 36, 39, 20, 20, 21, 30, 37,
+	20, 0, 29, 2, 4, 6, 8, 20,
+	20, 11, 13, 15, 17, 38, 19, 0
 };
 
-static const char _khmer_syllable_machine_to_state_actions[] = {
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 6, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0
+static const signed char _khmer_syllable_machine_cond_actions[] = {
+	1, 0, 2, 2, 2, 0, 0, 0,
+	2, 0, 2, 0, 2, 3, 0, 4,
+	5, 2, 0, 0, 0, 2, 0, 2,
+	0, 2, 4, 0, 8, 2, 9, 0,
+	10, 0, 0, 0, 0, 0, 0, 11,
+	12, 0, 0, 0, 0, 4, 0, 0
 };
 
-static const char _khmer_syllable_machine_from_state_actions[] = {
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 7, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0
+static const signed char _khmer_syllable_machine_to_state_actions[] = {
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 6, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0
 };
 
-static const unsigned char _khmer_syllable_machine_eof_trans[] = {
-	1, 1, 1, 1, 1, 1, 1, 1, 
-	1, 1, 14, 17, 17, 17, 17, 17, 
-	17, 17, 17, 17, 0, 32, 32, 32, 
-	32, 32, 32, 32, 32, 32, 39, 40, 
-	40, 40, 40, 40, 40, 40, 40, 40
+static const signed char _khmer_syllable_machine_from_state_actions[] = {
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 7, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0
+};
+
+static const signed char _khmer_syllable_machine_eof_trans[] = {
+	1, 1, 1, 1, 1, 1, 1, 1,
+	1, 1, 14, 17, 17, 17, 17, 17,
+	17, 17, 17, 17, 28, 33, 33, 33,
+	33, 33, 33, 33, 33, 33, 40, 41,
+	41, 41, 41, 41, 41, 41, 41, 41,
+	0
 };
 
 static const int khmer_syllable_machine_start = 20;
@@ -215,156 +183,271 @@ static const int khmer_syllable_machine_error = -1;
 static const int khmer_syllable_machine_en_main = 20;
 
 
-#line 36 "hb-ot-shape-complex-khmer-machine.rl"
+#line 43 "hb-ot-shape-complex-khmer-machine.rl"
 
 
 
-#line 80 "hb-ot-shape-complex-khmer-machine.rl"
+#line 86 "hb-ot-shape-complex-khmer-machine.rl"
 
 
 #define found_syllable(syllable_type) \
-  HB_STMT_START { \
-    if (0) fprintf (stderr, "syllable %d..%d %s\n", ts, te, #syllable_type); \
-    for (unsigned int i = ts; i < te; i++) \
-      info[i].syllable() = (syllable_serial << 4) | khmer_##syllable_type; \
-    syllable_serial++; \
-    if (unlikely (syllable_serial == 16)) syllable_serial = 1; \
-  } HB_STMT_END
+HB_STMT_START { \
+	if (0) fprintf (stderr, "syllable %d..%d %s\n", ts, te, #syllable_type); \
+		for (unsigned int i = ts; i < te; i++) \
+	info[i].syllable() = (syllable_serial << 4) | syllable_type; \
+	syllable_serial++; \
+	if (unlikely (syllable_serial == 16)) syllable_serial = 1; \
+	} HB_STMT_END
 
 static void
 find_syllables_khmer (hb_buffer_t *buffer)
 {
-  unsigned int p, pe, eof, ts, te, act HB_UNUSED;
-  int cs;
-  hb_glyph_info_t *info = buffer->info;
-  
-#line 242 "hb-ot-shape-complex-khmer-machine.hh"
+	unsigned int p, pe, eof, ts, te, act HB_UNUSED;
+	int cs;
+	hb_glyph_info_t *info = buffer->info;
+	
+#line 210 "hb-ot-shape-complex-khmer-machine.hh"
 	{
-	cs = khmer_syllable_machine_start;
-	ts = 0;
-	te = 0;
-	act = 0;
+		cs = (int)khmer_syllable_machine_start;
+		ts = 0;
+		te = 0;
+		act = 0;
 	}
-
-#line 100 "hb-ot-shape-complex-khmer-machine.rl"
-
-
-  p = 0;
-  pe = eof = buffer->len;
-
-  unsigned int syllable_serial = 1;
-  
-#line 258 "hb-ot-shape-complex-khmer-machine.hh"
+	
+#line 106 "hb-ot-shape-complex-khmer-machine.rl"
+	
+	
+	p = 0;
+	pe = eof = buffer->len;
+	
+	unsigned int syllable_serial = 1;
+	
+#line 226 "hb-ot-shape-complex-khmer-machine.hh"
 	{
-	int _slen;
-	int _trans;
-	const unsigned char *_keys;
-	const char *_inds;
-	if ( p == pe )
-		goto _test_eof;
-_resume:
-	switch ( _khmer_syllable_machine_from_state_actions[cs] ) {
-	case 7:
+		unsigned int _trans = 0;
+		const unsigned char * _keys;
+		const signed char * _inds;
+		int _ic;
+		_resume: {}
+		if ( p == pe && p != eof )
+			goto _out;
+		switch ( _khmer_syllable_machine_from_state_actions[cs] ) {
+			case 7:  {
+				{
 #line 1 "NONE"
-	{ts = p;}
-	break;
-#line 272 "hb-ot-shape-complex-khmer-machine.hh"
-	}
-
-	_keys = _khmer_syllable_machine_trans_keys + (cs<<1);
-	_inds = _khmer_syllable_machine_indicies + _khmer_syllable_machine_index_offsets[cs];
-
-	_slen = _khmer_syllable_machine_key_spans[cs];
-	_trans = _inds[ _slen > 0 && _keys[0] <=( info[p].khmer_category()) &&
-		( info[p].khmer_category()) <= _keys[1] ?
-		( info[p].khmer_category()) - _keys[0] : _slen ];
-
-_eof_trans:
-	cs = _khmer_syllable_machine_trans_targs[_trans];
-
-	if ( _khmer_syllable_machine_trans_actions[_trans] == 0 )
-		goto _again;
-
-	switch ( _khmer_syllable_machine_trans_actions[_trans] ) {
-	case 2:
+					{ts = p;}}
+				
+#line 241 "hb-ot-shape-complex-khmer-machine.hh"
+				
+				
+				break; 
+			}
+		}
+		
+		if ( p == eof ) {
+			if ( _khmer_syllable_machine_eof_trans[cs] > 0 ) {
+				_trans = (unsigned int)_khmer_syllable_machine_eof_trans[cs] - 1;
+			}
+		}
+		else {
+			_keys = ( _khmer_syllable_machine_trans_keys + ((cs<<1)));
+			_inds = ( _khmer_syllable_machine_indicies + (_khmer_syllable_machine_index_offsets[cs]));
+			
+			if ( (info[p].khmer_category()) <= 29 && (info[p].khmer_category()) >= 1 ) {
+				_ic = (int)_khmer_syllable_machine_char_class[(int)(info[p].khmer_category()) - 1];
+				if ( _ic <= (int)(*( _keys+1)) && _ic >= (int)(*( _keys)) )
+					_trans = (unsigned int)(*( _inds + (int)( _ic - (int)(*( _keys)) ) )); 
+				else
+					_trans = (unsigned int)_khmer_syllable_machine_index_defaults[cs];
+			}
+			else {
+				_trans = (unsigned int)_khmer_syllable_machine_index_defaults[cs];
+			}
+			
+		}
+		cs = (int)_khmer_syllable_machine_cond_targs[_trans];
+		
+		if ( _khmer_syllable_machine_cond_actions[_trans] != 0 ) {
+			
+			switch ( _khmer_syllable_machine_cond_actions[_trans] ) {
+				case 2:  {
+					{
 #line 1 "NONE"
-	{te = p+1;}
-	break;
-	case 8:
-#line 76 "hb-ot-shape-complex-khmer-machine.rl"
-	{te = p+1;{ found_syllable (non_khmer_cluster); }}
-	break;
-	case 10:
-#line 74 "hb-ot-shape-complex-khmer-machine.rl"
-	{te = p;p--;{ found_syllable (consonant_syllable); }}
-	break;
-	case 12:
-#line 75 "hb-ot-shape-complex-khmer-machine.rl"
-	{te = p;p--;{ found_syllable (broken_cluster); }}
-	break;
-	case 11:
-#line 76 "hb-ot-shape-complex-khmer-machine.rl"
-	{te = p;p--;{ found_syllable (non_khmer_cluster); }}
-	break;
-	case 1:
-#line 74 "hb-ot-shape-complex-khmer-machine.rl"
-	{{p = ((te))-1;}{ found_syllable (consonant_syllable); }}
-	break;
-	case 5:
-#line 75 "hb-ot-shape-complex-khmer-machine.rl"
-	{{p = ((te))-1;}{ found_syllable (broken_cluster); }}
-	break;
-	case 3:
+						{te = p+1;}}
+					
+#line 279 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 8:  {
+					{
+#line 82 "hb-ot-shape-complex-khmer-machine.rl"
+						{te = p+1;{
+#line 82 "hb-ot-shape-complex-khmer-machine.rl"
+								found_syllable (khmer_non_khmer_cluster); }
+						}}
+					
+#line 292 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 10:  {
+					{
+#line 80 "hb-ot-shape-complex-khmer-machine.rl"
+						{te = p;p = p - 1;{
+#line 80 "hb-ot-shape-complex-khmer-machine.rl"
+								found_syllable (khmer_consonant_syllable); }
+						}}
+					
+#line 305 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 12:  {
+					{
+#line 81 "hb-ot-shape-complex-khmer-machine.rl"
+						{te = p;p = p - 1;{
+#line 81 "hb-ot-shape-complex-khmer-machine.rl"
+								found_syllable (khmer_broken_cluster); }
+						}}
+					
+#line 318 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 11:  {
+					{
+#line 82 "hb-ot-shape-complex-khmer-machine.rl"
+						{te = p;p = p - 1;{
+#line 82 "hb-ot-shape-complex-khmer-machine.rl"
+								found_syllable (khmer_non_khmer_cluster); }
+						}}
+					
+#line 331 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 1:  {
+					{
+#line 80 "hb-ot-shape-complex-khmer-machine.rl"
+						{p = ((te))-1;
+							{
+#line 80 "hb-ot-shape-complex-khmer-machine.rl"
+								found_syllable (khmer_consonant_syllable); }
+						}}
+					
+#line 345 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 5:  {
+					{
+#line 81 "hb-ot-shape-complex-khmer-machine.rl"
+						{p = ((te))-1;
+							{
+#line 81 "hb-ot-shape-complex-khmer-machine.rl"
+								found_syllable (khmer_broken_cluster); }
+						}}
+					
+#line 359 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 3:  {
+					{
 #line 1 "NONE"
-	{	switch( act ) {
-	case 2:
-	{{p = ((te))-1;} found_syllable (broken_cluster); }
-	break;
-	case 3:
-	{{p = ((te))-1;} found_syllable (non_khmer_cluster); }
-	break;
-	}
-	}
-	break;
-	case 4:
+						{switch( act ) {
+								case 2:  {
+									p = ((te))-1;
+									{
+#line 81 "hb-ot-shape-complex-khmer-machine.rl"
+										found_syllable (khmer_broken_cluster); }
+									break; 
+								}
+								case 3:  {
+									p = ((te))-1;
+									{
+#line 82 "hb-ot-shape-complex-khmer-machine.rl"
+										found_syllable (khmer_non_khmer_cluster); }
+									break; 
+								}
+							}}
+					}
+					
+#line 385 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 4:  {
+					{
 #line 1 "NONE"
-	{te = p+1;}
-#line 75 "hb-ot-shape-complex-khmer-machine.rl"
-	{act = 2;}
-	break;
-	case 9:
+						{te = p+1;}}
+					
+#line 395 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					{
+#line 81 "hb-ot-shape-complex-khmer-machine.rl"
+						{act = 2;}}
+					
+#line 401 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+				case 9:  {
+					{
 #line 1 "NONE"
-	{te = p+1;}
-#line 76 "hb-ot-shape-complex-khmer-machine.rl"
-	{act = 3;}
-	break;
-#line 342 "hb-ot-shape-complex-khmer-machine.hh"
-	}
-
-_again:
-	switch ( _khmer_syllable_machine_to_state_actions[cs] ) {
-	case 6:
+						{te = p+1;}}
+					
+#line 411 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					{
+#line 82 "hb-ot-shape-complex-khmer-machine.rl"
+						{act = 3;}}
+					
+#line 417 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+			}
+			
+		}
+		
+		if ( p == eof ) {
+			if ( cs >= 20 )
+				goto _out;
+		}
+		else {
+			switch ( _khmer_syllable_machine_to_state_actions[cs] ) {
+				case 6:  {
+					{
 #line 1 "NONE"
-	{ts = 0;}
-	break;
-#line 351 "hb-ot-shape-complex-khmer-machine.hh"
-	}
-
-	if ( ++p != pe )
-		goto _resume;
-	_test_eof: {}
-	if ( p == eof )
-	{
-	if ( _khmer_syllable_machine_eof_trans[cs] > 0 ) {
-		_trans = _khmer_syllable_machine_eof_trans[cs] - 1;
-		goto _eof_trans;
-	}
+						{ts = 0;}}
+					
+#line 437 "hb-ot-shape-complex-khmer-machine.hh"
+					
+					
+					break; 
+				}
+			}
+			
+			p += 1;
+			goto _resume;
+		}
+		_out: {}
 	}
-
-	}
-
-#line 108 "hb-ot-shape-complex-khmer-machine.rl"
-
+	
+#line 114 "hb-ot-shape-complex-khmer-machine.rl"
+	
 }
 
 #undef found_syllable
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer-machine.rl b/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer-machine.rl
deleted file mode 100644
index e7f14533dd..0000000000
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer-machine.rl
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * Copyright © 2011,2012  Google, Inc.
- *
- *  This is part of HarfBuzz, a text shaping library.
- *
- * Permission is hereby granted, without written agreement and without
- * license or royalty fees, to use, copy, modify, and distribute this
- * software and its documentation for any purpose, provided that the
- * above copyright notice and the following two paragraphs appear in
- * all copies of this software.
- *
- * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
- * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
- * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
- * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
- * DAMAGE.
- *
- * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
- * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
- * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
- * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- *
- * Google Author(s): Behdad Esfahbod
- */
-
-#ifndef HB_OT_SHAPE_COMPLEX_KHMER_MACHINE_HH
-#define HB_OT_SHAPE_COMPLEX_KHMER_MACHINE_HH
-
-#include "hb.hh"
-
-%%{
-  machine khmer_syllable_machine;
-  alphtype unsigned char;
-  write data;
-}%%
-
-%%{
-
-# Same order as enum khmer_category_t.  Not sure how to avoid duplication.
-C    = 1;
-V    = 2;
-ZWNJ = 5;
-ZWJ  = 6;
-PLACEHOLDER = 11;
-DOTTEDCIRCLE = 12;
-Coeng= 14;
-Ra   = 16;
-Robatic = 20;
-Xgroup  = 21;
-Ygroup  = 22;
-VAbv = 26;
-VBlw = 27;
-VPre = 28;
-VPst = 29;
-
-c = (C | Ra | V);
-cn = c.((ZWJ|ZWNJ)?.Robatic)?;
-joiner = (ZWJ | ZWNJ);
-xgroup = (joiner*.Xgroup)*;
-ygroup = Ygroup*;
-
-# This grammar was experimentally extracted from what Uniscribe allows.
-
-matra_group = VPre? xgroup VBlw? xgroup (joiner?.VAbv)? xgroup VPst?;
-syllable_tail = xgroup matra_group xgroup (Coeng.c)? ygroup;
-
-
-broken_cluster =	(Coeng.cn)* (Coeng | syllable_tail);
-consonant_syllable =	(cn|PLACEHOLDER|DOTTEDCIRCLE) broken_cluster;
-other =			any;
-
-main := |*
-	consonant_syllable	=> { found_syllable (consonant_syllable); };
-	broken_cluster		=> { found_syllable (broken_cluster); };
-	other			=> { found_syllable (non_khmer_cluster); };
-*|;
-
-
-}%%
-
-#define found_syllable(syllable_type) \
-  HB_STMT_START { \
-    if (0) fprintf (stderr, "syllable %d..%d %s\n", ts, te, #syllable_type); \
-    for (unsigned int i = ts; i < te; i++) \
-      info[i].syllable() = (syllable_serial << 4) | khmer_##syllable_type; \
-    syllable_serial++; \
-    if (unlikely (syllable_serial == 16)) syllable_serial = 1; \
-  } HB_STMT_END
-
-static void
-find_syllables_khmer (hb_buffer_t *buffer)
-{
-  unsigned int p, pe, eof, ts, te, act HB_UNUSED;
-  int cs;
-  hb_glyph_info_t *info = buffer->info;
-  %%{
-    write init;
-    getkey info[p].khmer_category();
-  }%%
-
-  p = 0;
-  pe = eof = buffer->len;
-
-  unsigned int syllable_serial = 1;
-  %%{
-    write exec;
-  }%%
-}
-
-#undef found_syllable
-
-#endif /* HB_OT_SHAPE_COMPLEX_KHMER_MACHINE_HH */
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer.cc
index d6fcd7c814..dddba142a3 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer.cc
@@ -29,6 +29,7 @@
 #ifndef HB_NO_OT_SHAPE
 
 #include "hb-ot-shape-complex-khmer.hh"
+#include "hb-ot-shape-complex-khmer-machine.hh"
 #include "hb-ot-layout.hh"
 
 
@@ -140,27 +141,6 @@ override_features_khmer (hb_ot_shape_planner_t *plan)
 
 struct khmer_shape_plan_t
 {
-  bool get_virama_glyph (hb_font_t *font, hb_codepoint_t *pglyph) const
-  {
-    hb_codepoint_t glyph = virama_glyph;
-    if (unlikely (virama_glyph == (hb_codepoint_t) -1))
-    {
-      if (!font->get_nominal_glyph (0x17D2u, &glyph))
-	glyph = 0;
-      /* Technically speaking, the spec says we should apply 'locl' to virama too.
-       * Maybe one day... */
-
-      /* Our get_nominal_glyph() function needs a font, so we can't get the virama glyph
-       * during shape planning...  Instead, overwrite it here.  It's safe.  Don't worry! */
-      virama_glyph = glyph;
-    }
-
-    *pglyph = glyph;
-    return glyph != 0;
-  }
-
-  mutable hb_codepoint_t virama_glyph;
-
   hb_mask_t mask_array[KHMER_NUM_FEATURES];
 };
 
@@ -171,8 +151,6 @@ data_create_khmer (const hb_ot_shape_plan_t *plan)
   if (unlikely (!khmer_plan))
     return nullptr;
 
-  khmer_plan->virama_glyph = (hb_codepoint_t) -1;
-
   for (unsigned int i = 0; i < ARRAY_LENGTH (khmer_plan->mask_array); i++)
     khmer_plan->mask_array[i] = (khmer_features[i].flags & F_GLOBAL) ?
 				 0 : plan->map.get_1_mask (khmer_features[i].tag);
@@ -186,15 +164,6 @@ data_destroy_khmer (void *data)
   free (data);
 }
 
-
-enum khmer_syllable_type_t {
-  khmer_consonant_syllable,
-  khmer_broken_cluster,
-  khmer_non_khmer_cluster,
-};
-
-#include "hb-ot-shape-complex-khmer-machine.hh"
-
 static void
 setup_masks_khmer (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		   hb_buffer_t              *buffer,
@@ -321,76 +290,17 @@ reorder_syllable_khmer (const hb_ot_shape_plan_t *plan,
   }
 }
 
-static inline void
-insert_dotted_circles_khmer (const hb_ot_shape_plan_t *plan HB_UNUSED,
-			     hb_font_t *font,
-			     hb_buffer_t *buffer)
-{
-  if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
-    return;
-
-  /* Note: This loop is extra overhead, but should not be measurable.
-   * TODO Use a buffer scratch flag to remove the loop. */
-  bool has_broken_syllables = false;
-  unsigned int count = buffer->len;
-  hb_glyph_info_t *info = buffer->info;
-  for (unsigned int i = 0; i < count; i++)
-    if ((info[i].syllable() & 0x0F) == khmer_broken_cluster)
-    {
-      has_broken_syllables = true;
-      break;
-    }
-  if (likely (!has_broken_syllables))
-    return;
-
-
-  hb_codepoint_t dottedcircle_glyph;
-  if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
-    return;
-
-  hb_glyph_info_t dottedcircle = {0};
-  dottedcircle.codepoint = 0x25CCu;
-  set_khmer_properties (dottedcircle);
-  dottedcircle.codepoint = dottedcircle_glyph;
-
-  buffer->clear_output ();
-
-  buffer->idx = 0;
-  unsigned int last_syllable = 0;
-  while (buffer->idx < buffer->len && buffer->successful)
-  {
-    unsigned int syllable = buffer->cur().syllable();
-    khmer_syllable_type_t syllable_type = (khmer_syllable_type_t) (syllable & 0x0F);
-    if (unlikely (last_syllable != syllable && syllable_type == khmer_broken_cluster))
-    {
-      last_syllable = syllable;
-
-      hb_glyph_info_t ginfo = dottedcircle;
-      ginfo.cluster = buffer->cur().cluster;
-      ginfo.mask = buffer->cur().mask;
-      ginfo.syllable() = buffer->cur().syllable();
-
-      /* Insert dottedcircle after possible Repha. */
-      while (buffer->idx < buffer->len && buffer->successful &&
-	     last_syllable == buffer->cur().syllable() &&
-	     buffer->cur().khmer_category() == OT_Repha)
-	buffer->next_glyph ();
-
-      buffer->output_info (ginfo);
-    }
-    else
-      buffer->next_glyph ();
-  }
-  buffer->swap_buffers ();
-}
-
 static void
 reorder_khmer (const hb_ot_shape_plan_t *plan,
 	       hb_font_t *font,
 	       hb_buffer_t *buffer)
 {
-  if (buffer->message (font, "start reordering khmer")) {
-    insert_dotted_circles_khmer (plan, font, buffer);
+  if (buffer->message (font, "start reordering khmer"))
+  {
+    hb_syllabic_insert_dotted_circles (font, buffer,
+				       khmer_broken_cluster,
+				       OT_DOTTEDCIRCLE,
+				       OT_Repha);
 
     foreach_syllable (buffer, start, end)
       reorder_syllable_khmer (plan, font->face, buffer, start, end);
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer.hh
index 11a77bfd4b..e24d68a8b5 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-khmer.hh
@@ -54,7 +54,7 @@ set_khmer_properties (hb_glyph_info_t &info)
 {
   hb_codepoint_t u = info.codepoint;
   unsigned int type = hb_indic_get_categories (u);
-  khmer_category_t cat = (khmer_category_t) (type & 0x7Fu);
+  khmer_category_t cat = (khmer_category_t) (type & 0xFFu);
   indic_position_t pos = (indic_position_t) (type >> 8);
 
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-machine-index.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-machine-index.hh
deleted file mode 100644
index 9ec1f3eb7c..0000000000
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-machine-index.hh
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright © 2019,2020  David Corbett
- *
- *  This is part of HarfBuzz, a text shaping library.
- *
- * Permission is hereby granted, without written agreement and without
- * license or royalty fees, to use, copy, modify, and distribute this
- * software and its documentation for any purpose, provided that the
- * above copyright notice and the following two paragraphs appear in
- * all copies of this software.
- *
- * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
- * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
- * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
- * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
- * DAMAGE.
- *
- * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
- * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
- * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
- * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- */
-
-#ifndef HB_OT_SHAPE_COMPLEX_MACHINE_INDEX_HH
-#define HB_OT_SHAPE_COMPLEX_MACHINE_INDEX_HH
-
-#include "hb.hh"
-
-
-template <typename Iter>
-struct machine_index_t :
-  hb_iter_with_fallback_t<machine_index_t<Iter>,
-			  typename Iter::item_t>
-{
-  machine_index_t (const Iter& it) : it (it) {}
-  machine_index_t (const machine_index_t& o) : it (o.it) {}
-
-  static constexpr bool is_random_access_iterator = Iter::is_random_access_iterator;
-  static constexpr bool is_sorted_iterator = Iter::is_sorted_iterator;
-
-  typename Iter::item_t __item__ () const { return *it; }
-  typename Iter::item_t __item_at__ (unsigned i) const { return it[i]; }
-  unsigned __len__ () const { return it.len (); }
-  void __next__ () { ++it; }
-  void __forward__ (unsigned n) { it += n; }
-  void __prev__ () { --it; }
-  void __rewind__ (unsigned n) { it -= n; }
-  void operator = (unsigned n)
-  { unsigned index = (*it).first; if (index < n) it += n - index; else if (index > n) it -= index - n; }
-  void operator = (const machine_index_t& o) { *this = (*o.it).first; }
-  bool operator == (const machine_index_t& o) const { return (*it).first == (*o.it).first; }
-  bool operator != (const machine_index_t& o) const { return !(*this == o); }
-
-  private:
-  Iter it;
-};
-struct
-{
-  template <typename Iter,
-	    hb_requires (hb_is_iterable (Iter))>
-  machine_index_t<hb_iter_type<Iter>>
-  operator () (Iter&& it) const
-  { return machine_index_t<hb_iter_type<Iter>> (hb_iter (it)); }
-}
-HB_FUNCOBJ (machine_index);
-
-
-#endif /* HB_OT_SHAPE_COMPLEX_MACHINE_INDEX_HH */
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar-machine.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar-machine.hh
index c2f4c0045c..c09497896d 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar-machine.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar-machine.hh
@@ -31,8 +31,43 @@
 
 #include "hb.hh"
 
+enum myanmar_syllable_type_t {
+  myanmar_consonant_syllable,
+  myanmar_punctuation_cluster,
+  myanmar_broken_cluster,
+  myanmar_non_myanmar_cluster,
+};
+
 
-#line 36 "hb-ot-shape-complex-myanmar-machine.hh"
+#line 43 "hb-ot-shape-complex-myanmar-machine.hh"
+#define myanmar_syllable_machine_ex_A 10u
+#define myanmar_syllable_machine_ex_As 18u
+#define myanmar_syllable_machine_ex_C 1u
+#define myanmar_syllable_machine_ex_CS 19u
+#define myanmar_syllable_machine_ex_D 32u
+#define myanmar_syllable_machine_ex_D0 20u
+#define myanmar_syllable_machine_ex_DB 3u
+#define myanmar_syllable_machine_ex_GB 11u
+#define myanmar_syllable_machine_ex_H 4u
+#define myanmar_syllable_machine_ex_IV 2u
+#define myanmar_syllable_machine_ex_MH 21u
+#define myanmar_syllable_machine_ex_MR 22u
+#define myanmar_syllable_machine_ex_MW 23u
+#define myanmar_syllable_machine_ex_MY 24u
+#define myanmar_syllable_machine_ex_P 31u
+#define myanmar_syllable_machine_ex_PT 25u
+#define myanmar_syllable_machine_ex_Ra 16u
+#define myanmar_syllable_machine_ex_V 8u
+#define myanmar_syllable_machine_ex_VAbv 26u
+#define myanmar_syllable_machine_ex_VBlw 27u
+#define myanmar_syllable_machine_ex_VPre 28u
+#define myanmar_syllable_machine_ex_VPst 29u
+#define myanmar_syllable_machine_ex_VS 30u
+#define myanmar_syllable_machine_ex_ZWJ 6u
+#define myanmar_syllable_machine_ex_ZWNJ 5u
+
+
+#line 71 "hb-ot-shape-complex-myanmar-machine.hh"
 static const unsigned char _myanmar_syllable_machine_trans_keys[] = {
 	1u, 32u, 3u, 30u, 5u, 29u, 5u, 8u, 5u, 29u, 3u, 25u, 5u, 25u, 5u, 25u, 
 	3u, 29u, 3u, 29u, 3u, 29u, 3u, 29u, 1u, 16u, 3u, 29u, 3u, 29u, 3u, 29u, 
@@ -293,18 +328,18 @@ static const int myanmar_syllable_machine_error = -1;
 static const int myanmar_syllable_machine_en_main = 0;
 
 
-#line 36 "hb-ot-shape-complex-myanmar-machine.rl"
+#line 44 "hb-ot-shape-complex-myanmar-machine.rl"
 
 
 
-#line 94 "hb-ot-shape-complex-myanmar-machine.rl"
+#line 101 "hb-ot-shape-complex-myanmar-machine.rl"
 
 
 #define found_syllable(syllable_type) \
   HB_STMT_START { \
     if (0) fprintf (stderr, "syllable %d..%d %s\n", ts, te, #syllable_type); \
     for (unsigned int i = ts; i < te; i++) \
-      info[i].syllable() = (syllable_serial << 4) | myanmar_##syllable_type; \
+      info[i].syllable() = (syllable_serial << 4) | syllable_type; \
     syllable_serial++; \
     if (unlikely (syllable_serial == 16)) syllable_serial = 1; \
   } HB_STMT_END
@@ -316,7 +351,7 @@ find_syllables_myanmar (hb_buffer_t *buffer)
   int cs;
   hb_glyph_info_t *info = buffer->info;
   
-#line 320 "hb-ot-shape-complex-myanmar-machine.hh"
+#line 355 "hb-ot-shape-complex-myanmar-machine.hh"
 	{
 	cs = myanmar_syllable_machine_start;
 	ts = 0;
@@ -324,7 +359,7 @@ find_syllables_myanmar (hb_buffer_t *buffer)
 	act = 0;
 	}
 
-#line 114 "hb-ot-shape-complex-myanmar-machine.rl"
+#line 121 "hb-ot-shape-complex-myanmar-machine.rl"
 
 
   p = 0;
@@ -332,7 +367,7 @@ find_syllables_myanmar (hb_buffer_t *buffer)
 
   unsigned int syllable_serial = 1;
   
-#line 336 "hb-ot-shape-complex-myanmar-machine.hh"
+#line 371 "hb-ot-shape-complex-myanmar-machine.hh"
 	{
 	int _slen;
 	int _trans;
@@ -346,7 +381,7 @@ _resume:
 #line 1 "NONE"
 	{ts = p;}
 	break;
-#line 350 "hb-ot-shape-complex-myanmar-machine.hh"
+#line 385 "hb-ot-shape-complex-myanmar-machine.hh"
 	}
 
 	_keys = _myanmar_syllable_machine_trans_keys + (cs<<1);
@@ -365,38 +400,38 @@ _eof_trans:
 
 	switch ( _myanmar_syllable_machine_trans_actions[_trans] ) {
 	case 6:
-#line 86 "hb-ot-shape-complex-myanmar-machine.rl"
-	{te = p+1;{ found_syllable (consonant_syllable); }}
+#line 93 "hb-ot-shape-complex-myanmar-machine.rl"
+	{te = p+1;{ found_syllable (myanmar_consonant_syllable); }}
 	break;
 	case 4:
-#line 87 "hb-ot-shape-complex-myanmar-machine.rl"
-	{te = p+1;{ found_syllable (non_myanmar_cluster); }}
+#line 94 "hb-ot-shape-complex-myanmar-machine.rl"
+	{te = p+1;{ found_syllable (myanmar_non_myanmar_cluster); }}
 	break;
 	case 10:
-#line 88 "hb-ot-shape-complex-myanmar-machine.rl"
-	{te = p+1;{ found_syllable (punctuation_cluster); }}
+#line 95 "hb-ot-shape-complex-myanmar-machine.rl"
+	{te = p+1;{ found_syllable (myanmar_punctuation_cluster); }}
 	break;
 	case 8:
-#line 89 "hb-ot-shape-complex-myanmar-machine.rl"
-	{te = p+1;{ found_syllable (broken_cluster); }}
+#line 96 "hb-ot-shape-complex-myanmar-machine.rl"
+	{te = p+1;{ found_syllable (myanmar_broken_cluster); }}
 	break;
 	case 3:
-#line 90 "hb-ot-shape-complex-myanmar-machine.rl"
-	{te = p+1;{ found_syllable (non_myanmar_cluster); }}
+#line 97 "hb-ot-shape-complex-myanmar-machine.rl"
+	{te = p+1;{ found_syllable (myanmar_non_myanmar_cluster); }}
 	break;
 	case 5:
-#line 86 "hb-ot-shape-complex-myanmar-machine.rl"
-	{te = p;p--;{ found_syllable (consonant_syllable); }}
+#line 93 "hb-ot-shape-complex-myanmar-machine.rl"
+	{te = p;p--;{ found_syllable (myanmar_consonant_syllable); }}
 	break;
 	case 7:
-#line 89 "hb-ot-shape-complex-myanmar-machine.rl"
-	{te = p;p--;{ found_syllable (broken_cluster); }}
+#line 96 "hb-ot-shape-complex-myanmar-machine.rl"
+	{te = p;p--;{ found_syllable (myanmar_broken_cluster); }}
 	break;
 	case 9:
-#line 90 "hb-ot-shape-complex-myanmar-machine.rl"
-	{te = p;p--;{ found_syllable (non_myanmar_cluster); }}
+#line 97 "hb-ot-shape-complex-myanmar-machine.rl"
+	{te = p;p--;{ found_syllable (myanmar_non_myanmar_cluster); }}
 	break;
-#line 400 "hb-ot-shape-complex-myanmar-machine.hh"
+#line 435 "hb-ot-shape-complex-myanmar-machine.hh"
 	}
 
 _again:
@@ -405,7 +440,7 @@ _again:
 #line 1 "NONE"
 	{ts = 0;}
 	break;
-#line 409 "hb-ot-shape-complex-myanmar-machine.hh"
+#line 444 "hb-ot-shape-complex-myanmar-machine.hh"
 	}
 
 	if ( ++p != pe )
@@ -421,7 +456,7 @@ _again:
 
 	}
 
-#line 122 "hb-ot-shape-complex-myanmar-machine.rl"
+#line 129 "hb-ot-shape-complex-myanmar-machine.rl"
 
 }
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar.cc
index fe096ef28a..bc5dcb904c 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar.cc
@@ -29,6 +29,7 @@
 #ifndef HB_NO_OT_SHAPE
 
 #include "hb-ot-shape-complex-myanmar.hh"
+#include "hb-ot-shape-complex-myanmar-machine.hh"
 
 
 /*
@@ -97,17 +98,6 @@ collect_features_myanmar (hb_ot_shape_planner_t *plan)
     map->enable_feature (myanmar_other_features[i], F_MANUAL_ZWJ);
 }
 
-
-enum myanmar_syllable_type_t {
-  myanmar_consonant_syllable,
-  myanmar_punctuation_cluster,
-  myanmar_broken_cluster,
-  myanmar_non_myanmar_cluster,
-};
-
-#include "hb-ot-shape-complex-myanmar-machine.hh"
-
-
 static void
 setup_masks_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		     hb_buffer_t              *buffer,
@@ -265,70 +255,16 @@ reorder_syllable_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
   }
 }
 
-static inline void
-insert_dotted_circles_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
-			       hb_font_t *font,
-			       hb_buffer_t *buffer)
-{
-  if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
-    return;
-
-  /* Note: This loop is extra overhead, but should not be measurable.
-   * TODO Use a buffer scratch flag to remove the loop. */
-  bool has_broken_syllables = false;
-  unsigned int count = buffer->len;
-  hb_glyph_info_t *info = buffer->info;
-  for (unsigned int i = 0; i < count; i++)
-    if ((info[i].syllable() & 0x0F) == myanmar_broken_cluster)
-    {
-      has_broken_syllables = true;
-      break;
-    }
-  if (likely (!has_broken_syllables))
-    return;
-
-
-  hb_codepoint_t dottedcircle_glyph;
-  if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
-    return;
-
-  hb_glyph_info_t dottedcircle = {0};
-  dottedcircle.codepoint = 0x25CCu;
-  set_myanmar_properties (dottedcircle);
-  dottedcircle.codepoint = dottedcircle_glyph;
-
-  buffer->clear_output ();
-
-  buffer->idx = 0;
-  unsigned int last_syllable = 0;
-  while (buffer->idx < buffer->len && buffer->successful)
-  {
-    unsigned int syllable = buffer->cur().syllable();
-    myanmar_syllable_type_t syllable_type = (myanmar_syllable_type_t) (syllable & 0x0F);
-    if (unlikely (last_syllable != syllable && syllable_type == myanmar_broken_cluster))
-    {
-      last_syllable = syllable;
-
-      hb_glyph_info_t ginfo = dottedcircle;
-      ginfo.cluster = buffer->cur().cluster;
-      ginfo.mask = buffer->cur().mask;
-      ginfo.syllable() = buffer->cur().syllable();
-
-      buffer->output_info (ginfo);
-    }
-    else
-      buffer->next_glyph ();
-  }
-  buffer->swap_buffers ();
-}
-
 static void
 reorder_myanmar (const hb_ot_shape_plan_t *plan,
 		 hb_font_t *font,
 		 hb_buffer_t *buffer)
 {
-  if (buffer->message (font, "start reordering myanmar")) {
-    insert_dotted_circles_myanmar (plan, font, buffer);
+  if (buffer->message (font, "start reordering myanmar"))
+  {
+    hb_syllabic_insert_dotted_circles (font, buffer,
+				       myanmar_broken_cluster,
+				       OT_GB);
 
     foreach_syllable (buffer, start, end)
       reorder_syllable_myanmar (plan, font->face, buffer, start, end);
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar.hh
index 7b9821e6ba..a6d68aae57 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-myanmar.hh
@@ -64,7 +64,7 @@ set_myanmar_properties (hb_glyph_info_t &info)
 {
   hb_codepoint_t u = info.codepoint;
   unsigned int type = hb_indic_get_categories (u);
-  unsigned int cat = type & 0x7Fu;
+  unsigned int cat = type & 0xFFu;
   indic_position_t pos = (indic_position_t) (type >> 8);
 
   /* Myanmar
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-syllabic.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-syllabic.cc
new file mode 100644
index 0000000000..46509abee2
--- /dev/null
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-syllabic.cc
@@ -0,0 +1,100 @@
+/*
+ * Copyright © 2021  Behdad Esfahbod.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#include "hb.hh"
+
+#ifndef HB_NO_OT_SHAPE
+
+#include "hb-ot-shape-complex-syllabic.hh"
+
+
+void
+hb_syllabic_insert_dotted_circles (hb_font_t *font,
+				   hb_buffer_t *buffer,
+				   unsigned int broken_syllable_type,
+				   unsigned int dottedcircle_category,
+				   int repha_category)
+{
+  if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
+    return;
+
+  /* Note: This loop is extra overhead, but should not be measurable.
+   * TODO Use a buffer scratch flag to remove the loop. */
+  bool has_broken_syllables = false;
+  unsigned int count = buffer->len;
+  hb_glyph_info_t *info = buffer->info;
+  for (unsigned int i = 0; i < count; i++)
+    if ((info[i].syllable() & 0x0F) == broken_syllable_type)
+    {
+      has_broken_syllables = true;
+      break;
+    }
+  if (likely (!has_broken_syllables))
+    return;
+
+
+  hb_codepoint_t dottedcircle_glyph;
+  if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
+    return;
+
+  hb_glyph_info_t dottedcircle = {0};
+  dottedcircle.codepoint = 0x25CCu;
+  dottedcircle.complex_var_u8_category() = dottedcircle_category;
+  dottedcircle.codepoint = dottedcircle_glyph;
+
+  buffer->clear_output ();
+
+  buffer->idx = 0;
+  unsigned int last_syllable = 0;
+  while (buffer->idx < buffer->len && buffer->successful)
+  {
+    unsigned int syllable = buffer->cur().syllable();
+    if (unlikely (last_syllable != syllable && (syllable & 0x0F) == broken_syllable_type))
+    {
+      last_syllable = syllable;
+
+      hb_glyph_info_t ginfo = dottedcircle;
+      ginfo.cluster = buffer->cur().cluster;
+      ginfo.mask = buffer->cur().mask;
+      ginfo.syllable() = buffer->cur().syllable();
+
+      /* Insert dottedcircle after possible Repha. */
+      if (repha_category != -1)
+      {
+	while (buffer->idx < buffer->len && buffer->successful &&
+	       last_syllable == buffer->cur().syllable() &&
+	       buffer->cur().complex_var_u8_category() == (unsigned) repha_category)
+	  (void) buffer->next_glyph ();
+      }
+
+      (void) buffer->output_info (ginfo);
+    }
+    else
+      (void) buffer->next_glyph ();
+  }
+  buffer->swap_buffers ();
+}
+
+
+#endif
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-syllabic.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-syllabic.hh
new file mode 100644
index 0000000000..c80b8fee1d
--- /dev/null
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-syllabic.hh
@@ -0,0 +1,41 @@
+/*
+ * Copyright © 2021  Behdad Esfahbod.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#ifndef HB_OT_SHAPE_COMPLEX_SYLLABIC_HH
+#define HB_OT_SHAPE_COMPLEX_SYLLABIC_HH
+
+#include "hb.hh"
+
+#include "hb-ot-shape-complex.hh"
+
+
+HB_INTERNAL void
+hb_syllabic_insert_dotted_circles (hb_font_t *font,
+				   hb_buffer_t *buffer,
+				   unsigned int broken_syllable_type,
+				   unsigned int dottedcircle_category,
+				   int repha_category = -1);
+
+
+#endif /* HB_OT_SHAPE_COMPLEX_SYLLABIC_HH */
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-thai.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-thai.cc
index 347ea2e7ac..4c3068173b 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-thai.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-thai.cc
@@ -323,20 +323,19 @@ preprocess_text_thai (const hb_ot_shape_plan_t *plan,
 
   buffer->clear_output ();
   unsigned int count = buffer->len;
-  for (buffer->idx = 0; buffer->idx < count && buffer->successful;)
+  for (buffer->idx = 0; buffer->idx < count /* No need for: && buffer->successful */;)
   {
     hb_codepoint_t u = buffer->cur().codepoint;
-    if (likely (!IS_SARA_AM (u))) {
-      buffer->next_glyph ();
+    if (likely (!IS_SARA_AM (u)))
+    {
+      if (unlikely (!buffer->next_glyph ())) break;
       continue;
     }
 
     /* Is SARA AM. Decompose and reorder. */
-    hb_glyph_info_t &nikhahit = buffer->output_glyph (NIKHAHIT_FROM_SARA_AM (u));
-    _hb_glyph_info_set_continuation (&nikhahit);
-    buffer->replace_glyph (SARA_AA_FROM_SARA_AM (u));
-    if (unlikely (!buffer->successful))
-      return;
+    (void) buffer->output_glyph (NIKHAHIT_FROM_SARA_AM (u));
+    _hb_glyph_info_set_continuation (&buffer->prev());
+    if (unlikely (!buffer->replace_glyph (SARA_AA_FROM_SARA_AM (u)))) break;
 
     /* Make Nikhahit be recognized as a ccc=0 mark when zeroing widths. */
     unsigned int end = buffer->out_len;
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-use-machine.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-use-machine.hh
index 144e7d3a40..b4b2b75100 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-use-machine.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-use-machine.hh
@@ -1,300 +1,348 @@
-
 #line 1 "hb-ot-shape-complex-use-machine.rl"
 /*
- * Copyright © 2015  Mozilla Foundation.
- * Copyright © 2015  Google, Inc.
- *
- *  This is part of HarfBuzz, a text shaping library.
- *
- * Permission is hereby granted, without written agreement and without
- * license or royalty fees, to use, copy, modify, and distribute this
- * software and its documentation for any purpose, provided that the
- * above copyright notice and the following two paragraphs appear in
- * all copies of this software.
- *
- * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
- * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
- * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
- * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
- * DAMAGE.
- *
- * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
- * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
- * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
- * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- *
- * Mozilla Author(s): Jonathan Kew
- * Google Author(s): Behdad Esfahbod
- */
+* Copyright © 2015  Mozilla Foundation.
+* Copyright © 2015  Google, Inc.
+*
+*  This is part of HarfBuzz, a text shaping library.
+*
+* Permission is hereby granted, without written agreement and without
+* license or royalty fees, to use, copy, modify, and distribute this
+* software and its documentation for any purpose, provided that the
+* above copyright notice and the following two paragraphs appear in
+* all copies of this software.
+*
+* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+* DAMAGE.
+*
+* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+* FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+*
+* Mozilla Author(s): Jonathan Kew
+* Google Author(s): Behdad Esfahbod
+*/
 
 #ifndef HB_OT_SHAPE_COMPLEX_USE_MACHINE_HH
 #define HB_OT_SHAPE_COMPLEX_USE_MACHINE_HH
 
 #include "hb.hh"
-#include "hb-ot-shape-complex-machine-index.hh"
 
+#include "hb-ot-shape-complex-syllabic.hh"
+
+/* buffer var allocations */
+#define use_category() complex_var_u8_category()
+
+#define USE(Cat) use_syllable_machine_ex_##Cat
+
+enum use_syllable_type_t {
+	use_independent_cluster,
+	use_virama_terminated_cluster,
+	use_sakot_terminated_cluster,
+	use_standard_cluster,
+	use_number_joiner_terminated_cluster,
+	use_numeral_cluster,
+	use_symbol_cluster,
+	use_hieroglyph_cluster,
+	use_broken_cluster,
+	use_non_cluster,
+};
 
-#line 39 "hb-ot-shape-complex-use-machine.hh"
+
+#line 57 "hb-ot-shape-complex-use-machine.hh"
+#define use_syllable_machine_ex_B 1u
+#define use_syllable_machine_ex_CMAbv 31u
+#define use_syllable_machine_ex_CMBlw 32u
+#define use_syllable_machine_ex_CS 43u
+#define use_syllable_machine_ex_FAbv 24u
+#define use_syllable_machine_ex_FBlw 25u
+#define use_syllable_machine_ex_FMAbv 45u
+#define use_syllable_machine_ex_FMBlw 46u
+#define use_syllable_machine_ex_FMPst 47u
+#define use_syllable_machine_ex_FPst 26u
+#define use_syllable_machine_ex_G 49u
+#define use_syllable_machine_ex_GB 5u
+#define use_syllable_machine_ex_H 12u
+#define use_syllable_machine_ex_HN 13u
+#define use_syllable_machine_ex_HVM 44u
+#define use_syllable_machine_ex_J 50u
+#define use_syllable_machine_ex_MAbv 27u
+#define use_syllable_machine_ex_MBlw 28u
+#define use_syllable_machine_ex_MPre 30u
+#define use_syllable_machine_ex_MPst 29u
+#define use_syllable_machine_ex_N 4u
+#define use_syllable_machine_ex_O 0u
+#define use_syllable_machine_ex_R 18u
+#define use_syllable_machine_ex_S 19u
+#define use_syllable_machine_ex_SB 51u
+#define use_syllable_machine_ex_SE 52u
+#define use_syllable_machine_ex_SMAbv 41u
+#define use_syllable_machine_ex_SMBlw 42u
+#define use_syllable_machine_ex_SUB 11u
+#define use_syllable_machine_ex_Sk 48u
+#define use_syllable_machine_ex_VAbv 33u
+#define use_syllable_machine_ex_VBlw 34u
+#define use_syllable_machine_ex_VMAbv 37u
+#define use_syllable_machine_ex_VMBlw 38u
+#define use_syllable_machine_ex_VMPre 23u
+#define use_syllable_machine_ex_VMPst 39u
+#define use_syllable_machine_ex_VPre 22u
+#define use_syllable_machine_ex_VPst 35u
+#define use_syllable_machine_ex_ZWNJ 14u
+
+
+#line 99 "hb-ot-shape-complex-use-machine.hh"
 static const unsigned char _use_syllable_machine_trans_keys[] = {
-	1u, 1u, 1u, 1u, 0u, 51u, 11u, 48u, 11u, 48u, 1u, 1u, 22u, 48u, 23u, 48u, 
-	24u, 47u, 25u, 47u, 26u, 47u, 45u, 46u, 46u, 46u, 24u, 48u, 24u, 48u, 24u, 48u, 
-	1u, 1u, 24u, 48u, 23u, 48u, 23u, 48u, 23u, 48u, 22u, 48u, 22u, 48u, 22u, 48u, 
-	11u, 48u, 1u, 48u, 13u, 13u, 4u, 4u, 11u, 48u, 41u, 42u, 42u, 42u, 11u, 48u, 
-	22u, 48u, 23u, 48u, 24u, 47u, 25u, 47u, 26u, 47u, 45u, 46u, 46u, 46u, 24u, 48u, 
-	24u, 48u, 24u, 48u, 24u, 48u, 23u, 48u, 23u, 48u, 23u, 48u, 22u, 48u, 22u, 48u, 
-	22u, 48u, 11u, 48u, 1u, 48u, 1u, 1u, 4u, 4u, 13u, 13u, 1u, 48u, 11u, 48u, 
-	41u, 42u, 42u, 42u, 1u, 5u, 50u, 52u, 49u, 52u, 49u, 51u, 0
+	1u, 1u, 1u, 1u, 0u, 37u, 5u, 34u,
+	5u, 34u, 1u, 1u, 10u, 34u, 11u, 34u,
+	12u, 33u, 13u, 33u, 14u, 33u, 31u, 32u,
+	32u, 32u, 12u, 34u, 12u, 34u, 12u, 34u,
+	1u, 1u, 12u, 34u, 11u, 34u, 11u, 34u,
+	11u, 34u, 10u, 34u, 10u, 34u, 10u, 34u,
+	5u, 34u, 1u, 34u, 7u, 7u, 3u, 3u,
+	5u, 34u, 27u, 28u, 28u, 28u, 5u, 34u,
+	10u, 34u, 11u, 34u, 12u, 33u, 13u, 33u,
+	14u, 33u, 31u, 32u, 32u, 32u, 12u, 34u,
+	12u, 34u, 12u, 34u, 12u, 34u, 11u, 34u,
+	11u, 34u, 11u, 34u, 10u, 34u, 10u, 34u,
+	10u, 34u, 5u, 34u, 1u, 34u, 1u, 1u,
+	3u, 3u, 7u, 7u, 1u, 34u, 5u, 34u,
+	27u, 28u, 28u, 28u, 1u, 4u, 36u, 38u,
+	35u, 38u, 35u, 37u, 0u
 };
 
-static const char _use_syllable_machine_key_spans[] = {
-	1, 1, 52, 38, 38, 1, 27, 26, 
-	24, 23, 22, 2, 1, 25, 25, 25, 
-	1, 25, 26, 26, 26, 27, 27, 27, 
-	38, 48, 1, 1, 38, 2, 1, 38, 
-	27, 26, 24, 23, 22, 2, 1, 25, 
-	25, 25, 25, 26, 26, 26, 27, 27, 
-	27, 38, 48, 1, 1, 1, 48, 38, 
-	2, 1, 5, 3, 4, 3
+static const signed char _use_syllable_machine_char_class[] = {
+	0, 1, 2, 2, 3, 4, 2, 2,
+	2, 2, 2, 5, 6, 7, 2, 2,
+	2, 2, 8, 9, 2, 2, 10, 11,
+	12, 13, 14, 15, 16, 17, 18, 19,
+	20, 21, 22, 23, 2, 24, 25, 26,
+	2, 27, 28, 29, 30, 31, 32, 33,
+	34, 35, 36, 37, 38, 0
 };
 
 static const short _use_syllable_machine_index_offsets[] = {
-	0, 2, 4, 57, 96, 135, 137, 165, 
-	192, 217, 241, 264, 267, 269, 295, 321, 
-	347, 349, 375, 402, 429, 456, 484, 512, 
-	540, 579, 628, 630, 632, 671, 674, 676, 
-	715, 743, 770, 795, 819, 842, 845, 847, 
-	873, 899, 925, 951, 978, 1005, 1032, 1060, 
-	1088, 1116, 1155, 1204, 1206, 1208, 1210, 1259, 
-	1298, 1301, 1303, 1309, 1313, 1318
+	0, 1, 2, 40, 70, 100, 101, 126,
+	150, 172, 193, 213, 215, 216, 239, 262,
+	285, 286, 309, 333, 357, 381, 406, 431,
+	456, 486, 520, 521, 522, 552, 554, 555,
+	585, 610, 634, 656, 677, 697, 699, 700,
+	723, 746, 769, 792, 816, 840, 864, 889,
+	914, 939, 969, 1003, 1004, 1005, 1006, 1040,
+	1070, 1072, 1073, 1077, 1080, 1084, 0
+};
+
+static const signed char _use_syllable_machine_indicies[] = {
+	1, 2, 4, 5, 6, 7, 8, 1,
+	9, 10, 11, 12, 13, 14, 15, 16,
+	17, 18, 19, 13, 20, 21, 22, 23,
+	24, 25, 26, 27, 28, 29, 30, 31,
+	32, 33, 34, 35, 9, 36, 6, 37,
+	39, 40, 38, 38, 38, 41, 42, 43,
+	44, 45, 46, 47, 41, 48, 5, 49,
+	50, 51, 52, 53, 54, 55, 38, 38,
+	38, 56, 57, 58, 59, 40, 39, 40,
+	38, 38, 38, 41, 42, 43, 44, 45,
+	46, 47, 41, 48, 49, 49, 50, 51,
+	52, 53, 54, 55, 38, 38, 38, 56,
+	57, 58, 59, 40, 39, 41, 42, 43,
+	44, 45, 38, 38, 38, 38, 38, 38,
+	50, 51, 52, 53, 54, 55, 38, 38,
+	38, 42, 57, 58, 59, 61, 42, 43,
+	44, 45, 38, 38, 38, 38, 38, 38,
+	38, 38, 38, 53, 54, 55, 38, 38,
+	38, 38, 57, 58, 59, 61, 43, 44,
+	45, 38, 38, 38, 38, 38, 38, 38,
+	38, 38, 38, 38, 38, 38, 38, 38,
+	38, 57, 58, 59, 44, 45, 38, 38,
+	38, 38, 38, 38, 38, 38, 38, 38,
+	38, 38, 38, 38, 38, 38, 57, 58,
+	59, 45, 38, 38, 38, 38, 38, 38,
+	38, 38, 38, 38, 38, 38, 38, 38,
+	38, 38, 57, 58, 59, 57, 58, 58,
+	43, 44, 45, 38, 38, 38, 38, 38,
+	38, 38, 38, 38, 53, 54, 55, 38,
+	38, 38, 38, 57, 58, 59, 61, 43,
+	44, 45, 38, 38, 38, 38, 38, 38,
+	38, 38, 38, 38, 54, 55, 38, 38,
+	38, 38, 57, 58, 59, 61, 43, 44,
+	45, 38, 38, 38, 38, 38, 38, 38,
+	38, 38, 38, 38, 55, 38, 38, 38,
+	38, 57, 58, 59, 61, 63, 43, 44,
+	45, 38, 38, 38, 38, 38, 38, 38,
+	38, 38, 38, 38, 38, 38, 38, 38,
+	38, 57, 58, 59, 61, 42, 43, 44,
+	45, 38, 38, 38, 38, 38, 38, 50,
+	51, 52, 53, 54, 55, 38, 38, 38,
+	42, 57, 58, 59, 61, 42, 43, 44,
+	45, 38, 38, 38, 38, 38, 38, 38,
+	51, 52, 53, 54, 55, 38, 38, 38,
+	42, 57, 58, 59, 61, 42, 43, 44,
+	45, 38, 38, 38, 38, 38, 38, 38,
+	38, 52, 53, 54, 55, 38, 38, 38,
+	42, 57, 58, 59, 61, 41, 42, 43,
+	44, 45, 38, 47, 41, 38, 38, 38,
+	50, 51, 52, 53, 54, 55, 38, 38,
+	38, 42, 57, 58, 59, 61, 41, 42,
+	43, 44, 45, 38, 38, 41, 38, 38,
+	38, 50, 51, 52, 53, 54, 55, 38,
+	38, 38, 42, 57, 58, 59, 61, 41,
+	42, 43, 44, 45, 46, 47, 41, 38,
+	38, 38, 50, 51, 52, 53, 54, 55,
+	38, 38, 38, 42, 57, 58, 59, 61,
+	39, 40, 38, 38, 38, 41, 42, 43,
+	44, 45, 46, 47, 41, 48, 38, 49,
+	50, 51, 52, 53, 54, 55, 38, 38,
+	38, 56, 57, 58, 59, 40, 39, 60,
+	60, 60, 60, 60, 60, 60, 60, 60,
+	42, 43, 44, 45, 60, 60, 60, 60,
+	60, 60, 60, 60, 60, 53, 54, 55,
+	60, 60, 60, 60, 57, 58, 59, 61,
+	65, 7, 39, 40, 38, 38, 38, 41,
+	42, 43, 44, 45, 46, 47, 41, 48,
+	5, 49, 50, 51, 52, 53, 54, 55,
+	12, 67, 38, 56, 57, 58, 59, 40,
+	12, 67, 67, 1, 70, 69, 69, 69,
+	13, 14, 15, 16, 17, 18, 19, 13,
+	20, 22, 22, 23, 24, 25, 26, 27,
+	28, 69, 69, 69, 32, 33, 34, 35,
+	70, 13, 14, 15, 16, 17, 69, 69,
+	69, 69, 69, 69, 23, 24, 25, 26,
+	27, 28, 69, 69, 69, 14, 33, 34,
+	35, 71, 14, 15, 16, 17, 69, 69,
+	69, 69, 69, 69, 69, 69, 69, 26,
+	27, 28, 69, 69, 69, 69, 33, 34,
+	35, 71, 15, 16, 17, 69, 69, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	69, 69, 69, 69, 69, 33, 34, 35,
+	16, 17, 69, 69, 69, 69, 69, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	69, 69, 33, 34, 35, 17, 69, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	69, 69, 69, 69, 69, 69, 33, 34,
+	35, 33, 34, 34, 15, 16, 17, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	26, 27, 28, 69, 69, 69, 69, 33,
+	34, 35, 71, 15, 16, 17, 69, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	27, 28, 69, 69, 69, 69, 33, 34,
+	35, 71, 15, 16, 17, 69, 69, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	28, 69, 69, 69, 69, 33, 34, 35,
+	71, 15, 16, 17, 69, 69, 69, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	69, 69, 69, 69, 33, 34, 35, 71,
+	14, 15, 16, 17, 69, 69, 69, 69,
+	69, 69, 23, 24, 25, 26, 27, 28,
+	69, 69, 69, 14, 33, 34, 35, 71,
+	14, 15, 16, 17, 69, 69, 69, 69,
+	69, 69, 69, 24, 25, 26, 27, 28,
+	69, 69, 69, 14, 33, 34, 35, 71,
+	14, 15, 16, 17, 69, 69, 69, 69,
+	69, 69, 69, 69, 25, 26, 27, 28,
+	69, 69, 69, 14, 33, 34, 35, 71,
+	13, 14, 15, 16, 17, 69, 19, 13,
+	69, 69, 69, 23, 24, 25, 26, 27,
+	28, 69, 69, 69, 14, 33, 34, 35,
+	71, 13, 14, 15, 16, 17, 69, 69,
+	13, 69, 69, 69, 23, 24, 25, 26,
+	27, 28, 69, 69, 69, 14, 33, 34,
+	35, 71, 13, 14, 15, 16, 17, 18,
+	19, 13, 69, 69, 69, 23, 24, 25,
+	26, 27, 28, 69, 69, 69, 14, 33,
+	34, 35, 71, 1, 70, 69, 69, 69,
+	13, 14, 15, 16, 17, 18, 19, 13,
+	20, 69, 22, 23, 24, 25, 26, 27,
+	28, 69, 69, 69, 32, 33, 34, 35,
+	70, 1, 69, 69, 69, 69, 69, 69,
+	69, 69, 69, 14, 15, 16, 17, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	26, 27, 28, 69, 69, 69, 69, 33,
+	34, 35, 71, 1, 73, 10, 5, 69,
+	69, 5, 1, 70, 10, 69, 69, 13,
+	14, 15, 16, 17, 18, 19, 13, 20,
+	21, 22, 23, 24, 25, 26, 27, 28,
+	29, 30, 69, 32, 33, 34, 35, 70,
+	1, 70, 69, 69, 69, 13, 14, 15,
+	16, 17, 18, 19, 13, 20, 21, 22,
+	23, 24, 25, 26, 27, 28, 69, 69,
+	69, 32, 33, 34, 35, 70, 29, 30,
+	30, 5, 72, 72, 5, 75, 74, 36,
+	36, 75, 74, 75, 36, 74, 37, 0
 };
 
-static const char _use_syllable_machine_indicies[] = {
-	1, 0, 2, 0, 3, 4, 5, 5, 
-	6, 7, 5, 5, 5, 5, 5, 1, 
-	8, 9, 5, 5, 5, 5, 10, 11, 
-	5, 5, 12, 13, 14, 15, 16, 17, 
-	18, 12, 19, 20, 21, 22, 23, 24, 
-	5, 25, 26, 27, 5, 28, 29, 30, 
-	31, 32, 33, 34, 8, 35, 5, 36, 
-	5, 38, 39, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 40, 41, 42, 43, 
-	44, 45, 46, 40, 47, 4, 48, 49, 
-	50, 51, 37, 52, 53, 54, 37, 37, 
-	37, 37, 55, 56, 57, 58, 39, 37, 
-	38, 39, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 40, 41, 42, 43, 44, 
-	45, 46, 40, 47, 48, 48, 49, 50, 
-	51, 37, 52, 53, 54, 37, 37, 37, 
-	37, 55, 56, 57, 58, 39, 37, 38, 
-	59, 40, 41, 42, 43, 44, 37, 37, 
-	37, 37, 37, 37, 49, 50, 51, 37, 
-	52, 53, 54, 37, 37, 37, 37, 41, 
-	56, 57, 58, 60, 37, 41, 42, 43, 
-	44, 37, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 52, 53, 54, 37, 37, 
-	37, 37, 37, 56, 57, 58, 60, 37, 
-	42, 43, 44, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 37, 56, 57, 58, 
-	37, 43, 44, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 37, 56, 57, 58, 
-	37, 44, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 56, 57, 58, 37, 
-	56, 57, 37, 57, 37, 42, 43, 44, 
-	37, 37, 37, 37, 37, 37, 37, 37, 
-	37, 37, 52, 53, 54, 37, 37, 37, 
-	37, 37, 56, 57, 58, 60, 37, 42, 
-	43, 44, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 37, 53, 54, 37, 
-	37, 37, 37, 37, 56, 57, 58, 60, 
-	37, 42, 43, 44, 37, 37, 37, 37, 
-	37, 37, 37, 37, 37, 37, 37, 37, 
-	54, 37, 37, 37, 37, 37, 56, 57, 
-	58, 60, 37, 62, 61, 42, 43, 44, 
-	37, 37, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 37, 37, 37, 37, 37, 
-	37, 37, 56, 57, 58, 60, 37, 41, 
-	42, 43, 44, 37, 37, 37, 37, 37, 
-	37, 49, 50, 51, 37, 52, 53, 54, 
-	37, 37, 37, 37, 41, 56, 57, 58, 
-	60, 37, 41, 42, 43, 44, 37, 37, 
-	37, 37, 37, 37, 37, 50, 51, 37, 
-	52, 53, 54, 37, 37, 37, 37, 41, 
-	56, 57, 58, 60, 37, 41, 42, 43, 
-	44, 37, 37, 37, 37, 37, 37, 37, 
-	37, 51, 37, 52, 53, 54, 37, 37, 
-	37, 37, 41, 56, 57, 58, 60, 37, 
-	40, 41, 42, 43, 44, 37, 46, 40, 
-	37, 37, 37, 49, 50, 51, 37, 52, 
-	53, 54, 37, 37, 37, 37, 41, 56, 
-	57, 58, 60, 37, 40, 41, 42, 43, 
-	44, 37, 37, 40, 37, 37, 37, 49, 
-	50, 51, 37, 52, 53, 54, 37, 37, 
-	37, 37, 41, 56, 57, 58, 60, 37, 
-	40, 41, 42, 43, 44, 45, 46, 40, 
-	37, 37, 37, 49, 50, 51, 37, 52, 
-	53, 54, 37, 37, 37, 37, 41, 56, 
-	57, 58, 60, 37, 38, 39, 37, 37, 
-	37, 37, 37, 37, 37, 37, 37, 40, 
-	41, 42, 43, 44, 45, 46, 40, 47, 
-	37, 48, 49, 50, 51, 37, 52, 53, 
-	54, 37, 37, 37, 37, 55, 56, 57, 
-	58, 39, 37, 38, 59, 59, 59, 59, 
-	59, 59, 59, 59, 59, 59, 59, 59, 
-	59, 59, 59, 59, 59, 59, 59, 59, 
-	59, 41, 42, 43, 44, 59, 59, 59, 
-	59, 59, 59, 59, 59, 59, 59, 52, 
-	53, 54, 59, 59, 59, 59, 59, 56, 
-	57, 58, 60, 59, 64, 63, 6, 65, 
-	38, 39, 37, 37, 37, 37, 37, 37, 
-	37, 37, 37, 40, 41, 42, 43, 44, 
-	45, 46, 40, 47, 4, 48, 49, 50, 
-	51, 37, 52, 53, 54, 37, 11, 66, 
-	37, 55, 56, 57, 58, 39, 37, 11, 
-	66, 67, 66, 67, 1, 69, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 12, 
-	13, 14, 15, 16, 17, 18, 12, 19, 
-	21, 21, 22, 23, 24, 68, 25, 26, 
-	27, 68, 68, 68, 68, 31, 32, 33, 
-	34, 69, 68, 12, 13, 14, 15, 16, 
-	68, 68, 68, 68, 68, 68, 22, 23, 
-	24, 68, 25, 26, 27, 68, 68, 68, 
-	68, 13, 32, 33, 34, 70, 68, 13, 
-	14, 15, 16, 68, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 25, 26, 27, 
-	68, 68, 68, 68, 68, 32, 33, 34, 
-	70, 68, 14, 15, 16, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 32, 
-	33, 34, 68, 15, 16, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 32, 
-	33, 34, 68, 16, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 32, 33, 
-	34, 68, 32, 33, 68, 33, 68, 14, 
-	15, 16, 68, 68, 68, 68, 68, 68, 
-	68, 68, 68, 68, 25, 26, 27, 68, 
-	68, 68, 68, 68, 32, 33, 34, 70, 
-	68, 14, 15, 16, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 26, 
-	27, 68, 68, 68, 68, 68, 32, 33, 
-	34, 70, 68, 14, 15, 16, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 68, 
-	68, 68, 27, 68, 68, 68, 68, 68, 
-	32, 33, 34, 70, 68, 14, 15, 16, 
-	68, 68, 68, 68, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 68, 
-	68, 68, 32, 33, 34, 70, 68, 13, 
-	14, 15, 16, 68, 68, 68, 68, 68, 
-	68, 22, 23, 24, 68, 25, 26, 27, 
-	68, 68, 68, 68, 13, 32, 33, 34, 
-	70, 68, 13, 14, 15, 16, 68, 68, 
-	68, 68, 68, 68, 68, 23, 24, 68, 
-	25, 26, 27, 68, 68, 68, 68, 13, 
-	32, 33, 34, 70, 68, 13, 14, 15, 
-	16, 68, 68, 68, 68, 68, 68, 68, 
-	68, 24, 68, 25, 26, 27, 68, 68, 
-	68, 68, 13, 32, 33, 34, 70, 68, 
-	12, 13, 14, 15, 16, 68, 18, 12, 
-	68, 68, 68, 22, 23, 24, 68, 25, 
-	26, 27, 68, 68, 68, 68, 13, 32, 
-	33, 34, 70, 68, 12, 13, 14, 15, 
-	16, 68, 68, 12, 68, 68, 68, 22, 
-	23, 24, 68, 25, 26, 27, 68, 68, 
-	68, 68, 13, 32, 33, 34, 70, 68, 
-	12, 13, 14, 15, 16, 17, 18, 12, 
-	68, 68, 68, 22, 23, 24, 68, 25, 
-	26, 27, 68, 68, 68, 68, 13, 32, 
-	33, 34, 70, 68, 1, 69, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 12, 
-	13, 14, 15, 16, 17, 18, 12, 19, 
-	68, 21, 22, 23, 24, 68, 25, 26, 
-	27, 68, 68, 68, 68, 31, 32, 33, 
-	34, 69, 68, 1, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 68, 
-	68, 13, 14, 15, 16, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 68, 25, 
-	26, 27, 68, 68, 68, 68, 68, 32, 
-	33, 34, 70, 68, 1, 71, 72, 68, 
-	9, 68, 4, 68, 68, 68, 4, 68, 
-	68, 68, 68, 68, 1, 69, 9, 68, 
-	68, 68, 68, 68, 68, 68, 68, 12, 
-	13, 14, 15, 16, 17, 18, 12, 19, 
-	20, 21, 22, 23, 24, 68, 25, 26, 
-	27, 68, 28, 29, 68, 31, 32, 33, 
-	34, 69, 68, 1, 69, 68, 68, 68, 
-	68, 68, 68, 68, 68, 68, 12, 13, 
-	14, 15, 16, 17, 18, 12, 19, 20, 
-	21, 22, 23, 24, 68, 25, 26, 27, 
-	68, 68, 68, 68, 31, 32, 33, 34, 
-	69, 68, 28, 29, 68, 29, 68, 4, 
-	71, 71, 71, 4, 71, 74, 73, 35, 
-	73, 35, 74, 73, 74, 73, 35, 73, 
-	36, 73, 0
+static const signed char _use_syllable_machine_index_defaults[] = {
+	0, 0, 6, 38, 38, 60, 38, 38,
+	38, 38, 38, 38, 38, 38, 38, 38,
+	62, 38, 38, 38, 38, 38, 38, 38,
+	38, 60, 64, 66, 38, 68, 68, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	69, 69, 69, 69, 69, 69, 69, 69,
+	69, 69, 69, 72, 69, 69, 69, 69,
+	69, 69, 72, 74, 74, 74, 0
 };
 
-static const char _use_syllable_machine_trans_targs[] = {
-	2, 31, 42, 2, 3, 2, 26, 28, 
-	51, 52, 54, 29, 32, 33, 34, 35, 
-	36, 46, 47, 48, 55, 49, 43, 44, 
-	45, 39, 40, 41, 56, 57, 58, 50, 
-	37, 38, 2, 59, 61, 2, 4, 5, 
-	6, 7, 8, 9, 10, 21, 22, 23, 
-	24, 18, 19, 20, 13, 14, 15, 25, 
-	11, 12, 2, 2, 16, 2, 17, 2, 
-	27, 2, 30, 2, 2, 0, 1, 2, 
-	53, 2, 60
+static const signed char _use_syllable_machine_cond_targs[] = {
+	2, 31, 42, 2, 2, 3, 2, 26,
+	28, 51, 52, 54, 29, 32, 33, 34,
+	35, 36, 46, 47, 48, 55, 49, 43,
+	44, 45, 39, 40, 41, 56, 57, 58,
+	50, 37, 38, 2, 59, 61, 2, 4,
+	5, 6, 7, 8, 9, 10, 21, 22,
+	23, 24, 18, 19, 20, 13, 14, 15,
+	25, 11, 12, 2, 2, 16, 2, 17,
+	2, 27, 2, 30, 2, 2, 0, 1,
+	2, 53, 2, 60, 0
 };
 
-static const char _use_syllable_machine_trans_actions[] = {
-	1, 2, 2, 5, 0, 6, 0, 0, 
-	0, 0, 2, 0, 2, 2, 0, 0, 
-	0, 2, 2, 2, 2, 2, 2, 2, 
-	2, 2, 2, 2, 0, 0, 0, 2, 
-	0, 0, 7, 0, 0, 8, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 9, 10, 0, 11, 0, 12, 
-	0, 13, 0, 14, 15, 0, 0, 16, 
-	0, 17, 0
+static const signed char _use_syllable_machine_cond_actions[] = {
+	1, 2, 2, 0, 5, 0, 6, 0,
+	0, 0, 0, 2, 0, 2, 2, 0,
+	0, 0, 2, 2, 2, 2, 2, 2,
+	2, 2, 2, 2, 2, 0, 0, 0,
+	2, 0, 0, 7, 0, 0, 8, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 9, 10, 0, 11, 0,
+	12, 0, 13, 0, 14, 15, 0, 0,
+	16, 0, 17, 0, 0
 };
 
-static const char _use_syllable_machine_to_state_actions[] = {
-	0, 0, 3, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0
+static const signed char _use_syllable_machine_to_state_actions[] = {
+	0, 0, 3, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0
 };
 
-static const char _use_syllable_machine_from_state_actions[] = {
-	0, 0, 4, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0, 0, 0, 
-	0, 0, 0, 0, 0, 0
+static const signed char _use_syllable_machine_from_state_actions[] = {
+	0, 0, 4, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0
 };
 
-static const short _use_syllable_machine_eof_trans[] = {
-	1, 1, 0, 38, 38, 60, 38, 38, 
-	38, 38, 38, 38, 38, 38, 38, 38, 
-	62, 38, 38, 38, 38, 38, 38, 38, 
-	38, 60, 64, 66, 38, 68, 68, 69, 
-	69, 69, 69, 69, 69, 69, 69, 69, 
-	69, 69, 69, 69, 69, 69, 69, 69, 
-	69, 69, 69, 72, 69, 69, 69, 69, 
-	69, 69, 72, 74, 74, 74
+static const signed char _use_syllable_machine_eof_trans[] = {
+	1, 1, 4, 39, 39, 61, 39, 39,
+	39, 39, 39, 39, 39, 39, 39, 39,
+	63, 39, 39, 39, 39, 39, 39, 39,
+	39, 61, 65, 67, 39, 69, 69, 70,
+	70, 70, 70, 70, 70, 70, 70, 70,
+	70, 70, 70, 70, 70, 70, 70, 70,
+	70, 70, 70, 73, 70, 70, 70, 70,
+	70, 70, 73, 75, 75, 75, 0
 };
 
 static const int use_syllable_machine_start = 2;
@@ -304,185 +352,376 @@ static const int use_syllable_machine_error = -1;
 static const int use_syllable_machine_en_main = 2;
 
 
-#line 39 "hb-ot-shape-complex-use-machine.rl"
+#line 59 "hb-ot-shape-complex-use-machine.rl"
 
 
 
-#line 154 "hb-ot-shape-complex-use-machine.rl"
+#line 176 "hb-ot-shape-complex-use-machine.rl"
 
 
 #define found_syllable(syllable_type) \
-  HB_STMT_START { \
-    if (0) fprintf (stderr, "syllable %d..%d %s\n", (*ts).second.first, (*te).second.first, #syllable_type); \
-    for (unsigned i = (*ts).second.first; i < (*te).second.first; ++i) \
-      info[i].syllable() = (syllable_serial << 4) | use_##syllable_type; \
-    syllable_serial++; \
-    if (unlikely (syllable_serial == 16)) syllable_serial = 1; \
-  } HB_STMT_END
+HB_STMT_START { \
+	if (0) fprintf (stderr, "syllable %d..%d %s\n", (*ts).second.first, (*te).second.first, #syllable_type); \
+		for (unsigned i = (*ts).second.first; i < (*te).second.first; ++i) \
+	info[i].syllable() = (syllable_serial << 4) | syllable_type; \
+	syllable_serial++; \
+	if (unlikely (syllable_serial == 16)) syllable_serial = 1; \
+	} HB_STMT_END
+
+
+template <typename Iter>
+struct machine_index_t :
+hb_iter_with_fallback_t<machine_index_t<Iter>,
+typename Iter::item_t>
+{
+	machine_index_t (const Iter& it) : it (it) {}
+	machine_index_t (const machine_index_t& o) : it (o.it) {}
+	
+	static constexpr bool is_random_access_iterator = Iter::is_random_access_iterator;
+	static constexpr bool is_sorted_iterator = Iter::is_sorted_iterator;
+	
+	typename Iter::item_t __item__ () const { return *it; }
+	typename Iter::item_t __item_at__ (unsigned i) const { return it[i]; }
+	unsigned __len__ () const { return it.len (); }
+	void __next__ () { ++it; }
+	void __forward__ (unsigned n) { it += n; }
+	void __prev__ () { --it; }
+	void __rewind__ (unsigned n) { it -= n; }
+	void operator = (unsigned n)
+	{ unsigned index = (*it).first; if (index < n) it += n - index; else if (index > n) it -= index - n; }
+	void operator = (const machine_index_t& o) { *this = (*o.it).first; }
+	bool operator == (const machine_index_t& o) const { return (*it).first == (*o.it).first; }
+	bool operator != (const machine_index_t& o) const { return !(*this == o); }
+	
+	private:
+	Iter it;
+};
+struct
+{
+	template <typename Iter,
+	hb_requires (hb_is_iterable (Iter))>
+	machine_index_t<hb_iter_type<Iter>>
+	operator () (Iter&& it) const
+	{ return machine_index_t<hb_iter_type<Iter>> (hb_iter (it)); }
+}
+HB_FUNCOBJ (machine_index);
+
+
 
 static bool
 not_standard_default_ignorable (const hb_glyph_info_t &i)
-{ return !(i.use_category() == USE_O && _hb_glyph_info_is_default_ignorable (&i)); }
+{ return !(i.use_category() == USE(O) && _hb_glyph_info_is_default_ignorable (&i)); }
 
-static void
+static inline void
 find_syllables_use (hb_buffer_t *buffer)
 {
-  hb_glyph_info_t *info = buffer->info;
-  auto p =
-    + hb_iter (info, buffer->len)
-    | hb_enumerate
-    | hb_filter ([] (const hb_glyph_info_t &i) { return not_standard_default_ignorable (i); },
-		 hb_second)
-    | hb_filter ([&] (const hb_pair_t<unsigned, const hb_glyph_info_t &> p)
-		 {
-		   if (p.second.use_category() == USE_ZWNJ)
-		     for (unsigned i = p.first + 1; i < buffer->len; ++i)
-		       if (not_standard_default_ignorable (info[i]))
-			 return !_hb_glyph_info_is_unicode_mark (&info[i]);
-		   return true;
-		 })
-    | hb_enumerate
-    | machine_index
-    ;
-  auto pe = p + p.len ();
-  auto eof = +pe;
-  auto ts = +p;
-  auto te = +p;
-  unsigned int act HB_UNUSED;
-  int cs;
-  
-#line 355 "hb-ot-shape-complex-use-machine.hh"
+	hb_glyph_info_t *info = buffer->info;
+	auto p =
+	+ hb_iter (info, buffer->len)
+	| hb_enumerate
+	| hb_filter ([] (const hb_glyph_info_t &i) { return not_standard_default_ignorable (i); },
+	hb_second)
+	| hb_filter ([&] (const hb_pair_t<unsigned, const hb_glyph_info_t &> p)
+	{
+		if (p.second.use_category() == USE(ZWNJ))
+			for (unsigned i = p.first + 1; i < buffer->len; ++i)
+		if (not_standard_default_ignorable (info[i]))
+			return !_hb_glyph_info_is_unicode_mark (&info[i]);
+		return true;
+	})
+	| hb_enumerate
+	| machine_index
+	;
+	auto pe = p + p.len ();
+	auto eof = +pe;
+	auto ts = +p;
+	auto te = +p;
+	unsigned int act HB_UNUSED;
+	int cs;
+	
+#line 443 "hb-ot-shape-complex-use-machine.hh"
 	{
-	cs = use_syllable_machine_start;
-	ts = 0;
-	te = 0;
-	act = 0;
+		cs = (int)use_syllable_machine_start;
+		ts = 0;
+		te = 0;
 	}
-
-#line 198 "hb-ot-shape-complex-use-machine.rl"
-
-
-  unsigned int syllable_serial = 1;
-  
-#line 368 "hb-ot-shape-complex-use-machine.hh"
+	
+#line 260 "hb-ot-shape-complex-use-machine.rl"
+	
+	
+	unsigned int syllable_serial = 1;
+	
+#line 455 "hb-ot-shape-complex-use-machine.hh"
 	{
-	int _slen;
-	int _trans;
-	const unsigned char *_keys;
-	const char *_inds;
-	if ( p == pe )
-		goto _test_eof;
-_resume:
-	switch ( _use_syllable_machine_from_state_actions[cs] ) {
-	case 4:
+		unsigned int _trans = 0;
+		const unsigned char * _keys;
+		const signed char * _inds;
+		int _ic;
+		_resume: {}
+		if ( p == pe && p != eof )
+			goto _out;
+		switch ( _use_syllable_machine_from_state_actions[cs] ) {
+			case 4:  {
+				{
 #line 1 "NONE"
-	{ts = p;}
-	break;
-#line 382 "hb-ot-shape-complex-use-machine.hh"
-	}
-
-	_keys = _use_syllable_machine_trans_keys + (cs<<1);
-	_inds = _use_syllable_machine_indicies + _use_syllable_machine_index_offsets[cs];
-
-	_slen = _use_syllable_machine_key_spans[cs];
-	_trans = _inds[ _slen > 0 && _keys[0] <=( (*p).second.second.use_category()) &&
-		( (*p).second.second.use_category()) <= _keys[1] ?
-		( (*p).second.second.use_category()) - _keys[0] : _slen ];
-
-_eof_trans:
-	cs = _use_syllable_machine_trans_targs[_trans];
-
-	if ( _use_syllable_machine_trans_actions[_trans] == 0 )
-		goto _again;
-
-	switch ( _use_syllable_machine_trans_actions[_trans] ) {
-	case 2:
+					{ts = p;}}
+				
+#line 470 "hb-ot-shape-complex-use-machine.hh"
+				
+				
+				break; 
+			}
+		}
+		
+		if ( p == eof ) {
+			if ( _use_syllable_machine_eof_trans[cs] > 0 ) {
+				_trans = (unsigned int)_use_syllable_machine_eof_trans[cs] - 1;
+			}
+		}
+		else {
+			_keys = ( _use_syllable_machine_trans_keys + ((cs<<1)));
+			_inds = ( _use_syllable_machine_indicies + (_use_syllable_machine_index_offsets[cs]));
+			
+			if ( ((*p).second.second.use_category()) <= 52 ) {
+				_ic = (int)_use_syllable_machine_char_class[(int)((*p).second.second.use_category()) - 0];
+				if ( _ic <= (int)(*( _keys+1)) && _ic >= (int)(*( _keys)) )
+					_trans = (unsigned int)(*( _inds + (int)( _ic - (int)(*( _keys)) ) )); 
+				else
+					_trans = (unsigned int)_use_syllable_machine_index_defaults[cs];
+			}
+			else {
+				_trans = (unsigned int)_use_syllable_machine_index_defaults[cs];
+			}
+			
+		}
+		cs = (int)_use_syllable_machine_cond_targs[_trans];
+		
+		if ( _use_syllable_machine_cond_actions[_trans] != 0 ) {
+			
+			switch ( _use_syllable_machine_cond_actions[_trans] ) {
+				case 2:  {
+					{
 #line 1 "NONE"
-	{te = p+1;}
-	break;
-	case 5:
-#line 141 "hb-ot-shape-complex-use-machine.rl"
-	{te = p+1;{ found_syllable (independent_cluster); }}
-	break;
-	case 9:
-#line 144 "hb-ot-shape-complex-use-machine.rl"
-	{te = p+1;{ found_syllable (standard_cluster); }}
-	break;
-	case 7:
-#line 149 "hb-ot-shape-complex-use-machine.rl"
-	{te = p+1;{ found_syllable (broken_cluster); }}
-	break;
-	case 6:
-#line 150 "hb-ot-shape-complex-use-machine.rl"
-	{te = p+1;{ found_syllable (non_cluster); }}
-	break;
-	case 10:
-#line 142 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (virama_terminated_cluster); }}
-	break;
-	case 11:
-#line 143 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (sakot_terminated_cluster); }}
-	break;
-	case 8:
-#line 144 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (standard_cluster); }}
-	break;
-	case 13:
-#line 145 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (number_joiner_terminated_cluster); }}
-	break;
-	case 12:
-#line 146 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (numeral_cluster); }}
-	break;
-	case 14:
-#line 147 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (symbol_cluster); }}
-	break;
-	case 17:
-#line 148 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (hieroglyph_cluster); }}
-	break;
-	case 15:
-#line 149 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (broken_cluster); }}
-	break;
-	case 16:
-#line 150 "hb-ot-shape-complex-use-machine.rl"
-	{te = p;p--;{ found_syllable (non_cluster); }}
-	break;
-	case 1:
-#line 149 "hb-ot-shape-complex-use-machine.rl"
-	{{p = ((te))-1;}{ found_syllable (broken_cluster); }}
-	break;
-#line 460 "hb-ot-shape-complex-use-machine.hh"
-	}
-
-_again:
-	switch ( _use_syllable_machine_to_state_actions[cs] ) {
-	case 3:
+						{te = p+1;}}
+					
+#line 508 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 5:  {
+					{
+#line 163 "hb-ot-shape-complex-use-machine.rl"
+						{te = p+1;{
+#line 163 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_independent_cluster); }
+						}}
+					
+#line 521 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 9:  {
+					{
+#line 166 "hb-ot-shape-complex-use-machine.rl"
+						{te = p+1;{
+#line 166 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_standard_cluster); }
+						}}
+					
+#line 534 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 7:  {
+					{
+#line 171 "hb-ot-shape-complex-use-machine.rl"
+						{te = p+1;{
+#line 171 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_broken_cluster); }
+						}}
+					
+#line 547 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 6:  {
+					{
+#line 172 "hb-ot-shape-complex-use-machine.rl"
+						{te = p+1;{
+#line 172 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_non_cluster); }
+						}}
+					
+#line 560 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 10:  {
+					{
+#line 164 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 164 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_virama_terminated_cluster); }
+						}}
+					
+#line 573 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 11:  {
+					{
+#line 165 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 165 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_sakot_terminated_cluster); }
+						}}
+					
+#line 586 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 8:  {
+					{
+#line 166 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 166 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_standard_cluster); }
+						}}
+					
+#line 599 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 13:  {
+					{
+#line 167 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 167 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_number_joiner_terminated_cluster); }
+						}}
+					
+#line 612 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 12:  {
+					{
+#line 168 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 168 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_numeral_cluster); }
+						}}
+					
+#line 625 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 14:  {
+					{
+#line 169 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 169 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_symbol_cluster); }
+						}}
+					
+#line 638 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 17:  {
+					{
+#line 170 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 170 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_hieroglyph_cluster); }
+						}}
+					
+#line 651 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 15:  {
+					{
+#line 171 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 171 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_broken_cluster); }
+						}}
+					
+#line 664 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 16:  {
+					{
+#line 172 "hb-ot-shape-complex-use-machine.rl"
+						{te = p;p = p - 1;{
+#line 172 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_non_cluster); }
+						}}
+					
+#line 677 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+				case 1:  {
+					{
+#line 171 "hb-ot-shape-complex-use-machine.rl"
+						{p = ((te))-1;
+							{
+#line 171 "hb-ot-shape-complex-use-machine.rl"
+								found_syllable (use_broken_cluster); }
+						}}
+					
+#line 691 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+			}
+			
+		}
+		
+		if ( p == eof ) {
+			if ( cs >= 2 )
+				goto _out;
+		}
+		else {
+			switch ( _use_syllable_machine_to_state_actions[cs] ) {
+				case 3:  {
+					{
 #line 1 "NONE"
-	{ts = 0;}
-	break;
-#line 469 "hb-ot-shape-complex-use-machine.hh"
+						{ts = 0;}}
+					
+#line 711 "hb-ot-shape-complex-use-machine.hh"
+					
+					
+					break; 
+				}
+			}
+			
+			p += 1;
+			goto _resume;
+		}
+		_out: {}
 	}
-
-	if ( ++p != pe )
-		goto _resume;
-	_test_eof: {}
-	if ( p == eof )
-	{
-	if ( _use_syllable_machine_eof_trans[cs] > 0 ) {
-		_trans = _use_syllable_machine_eof_trans[cs] - 1;
-		goto _eof_trans;
-	}
-	}
-
-	}
-
-#line 203 "hb-ot-shape-complex-use-machine.rl"
-
+	
+#line 265 "hb-ot-shape-complex-use-machine.rl"
+	
 }
 
 #undef found_syllable
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-use-table.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-use-table.hh
index df3652b18a..a35894ce81 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-use-table.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-use-table.hh
@@ -31,56 +31,57 @@
  * UnicodeData.txt does not have a header.
  */
 
-#include "hb.hh"
+#ifndef HB_OT_SHAPE_COMPLEX_USE_TABLE_HH
+#define HB_OT_SHAPE_COMPLEX_USE_TABLE_HH
 
-#ifndef HB_NO_OT_SHAPE
+#include "hb.hh"
 
-#include "hb-ot-shape-complex-use.hh"
+#include "hb-ot-shape-complex-use-machine.hh"
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-macros"
-#define B	USE_B	/* BASE */
-#define CS	USE_CS	/* CONS_WITH_STACKER */
-#define G	USE_G	/* HIEROGLYPH */
-#define GB	USE_GB	/* BASE_OTHER */
-#define H	USE_H	/* HALANT */
-#define HN	USE_HN	/* HALANT_NUM */
-#define HVM	USE_HVM	/* HALANT_OR_VOWEL_MODIFIER */
-#define J	USE_J	/* HIEROGLYPH_JOINER */
-#define N	USE_N	/* BASE_NUM */
-#define O	USE_O	/* OTHER */
-#define R	USE_R	/* REPHA */
-#define S	USE_S	/* SYM */
-#define SB	USE_SB	/* HIEROGLYPH_SEGMENT_BEGIN */
-#define SE	USE_SE	/* HIEROGLYPH_SEGMENT_END */
-#define SUB	USE_SUB	/* CONS_SUB */
-#define Sk	USE_Sk	/* SAKOT */
-#define ZWNJ	USE_ZWNJ	/* ZWNJ */
-#define CMAbv	USE_CMAbv
-#define CMBlw	USE_CMBlw
-#define FAbv	USE_FAbv
-#define FBlw	USE_FBlw
-#define FPst	USE_FPst
-#define FMAbv	USE_FMAbv
-#define FMBlw	USE_FMBlw
-#define FMPst	USE_FMPst
-#define MAbv	USE_MAbv
-#define MBlw	USE_MBlw
-#define MPst	USE_MPst
-#define MPre	USE_MPre
-#define SMAbv	USE_SMAbv
-#define SMBlw	USE_SMBlw
-#define VAbv	USE_VAbv
-#define VBlw	USE_VBlw
-#define VPst	USE_VPst
-#define VPre	USE_VPre
-#define VMAbv	USE_VMAbv
-#define VMBlw	USE_VMBlw
-#define VMPst	USE_VMPst
-#define VMPre	USE_VMPre
+#define B	USE(B)	/* BASE */
+#define CS	USE(CS)	/* CONS_WITH_STACKER */
+#define G	USE(G)	/* HIEROGLYPH */
+#define GB	USE(GB)	/* BASE_OTHER */
+#define H	USE(H)	/* HALANT */
+#define HN	USE(HN)	/* HALANT_NUM */
+#define HVM	USE(HVM)	/* HALANT_OR_VOWEL_MODIFIER */
+#define J	USE(J)	/* HIEROGLYPH_JOINER */
+#define N	USE(N)	/* BASE_NUM */
+#define O	USE(O)	/* OTHER */
+#define R	USE(R)	/* REPHA */
+#define S	USE(S)	/* SYM */
+#define SB	USE(SB)	/* HIEROGLYPH_SEGMENT_BEGIN */
+#define SE	USE(SE)	/* HIEROGLYPH_SEGMENT_END */
+#define SUB	USE(SUB)	/* CONS_SUB */
+#define Sk	USE(Sk)	/* SAKOT */
+#define ZWNJ	USE(ZWNJ)	/* ZWNJ */
+#define CMAbv	USE(CMAbv)
+#define CMBlw	USE(CMBlw)
+#define FAbv	USE(FAbv)
+#define FBlw	USE(FBlw)
+#define FPst	USE(FPst)
+#define FMAbv	USE(FMAbv)
+#define FMBlw	USE(FMBlw)
+#define FMPst	USE(FMPst)
+#define MAbv	USE(MAbv)
+#define MBlw	USE(MBlw)
+#define MPst	USE(MPst)
+#define MPre	USE(MPre)
+#define SMAbv	USE(SMAbv)
+#define SMBlw	USE(SMBlw)
+#define VAbv	USE(VAbv)
+#define VBlw	USE(VBlw)
+#define VPst	USE(VPst)
+#define VPre	USE(VPre)
+#define VMAbv	USE(VMAbv)
+#define VMBlw	USE(VMBlw)
+#define VMPst	USE(VMPst)
+#define VMPre	USE(VMPre)
 #pragma GCC diagnostic pop
 
-static const USE_TABLE_ELEMENT_TYPE use_table[] = {
+static const uint8_t use_table[] = {
 
 
 #define use_offset_0x0028u 0
@@ -767,7 +768,7 @@ static const USE_TABLE_ELEMENT_TYPE use_table[] = {
 
   /* 11700 */     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,
   /* 11710 */     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     O,     O,  MBlw,  MPre,  MAbv,
-  /* 11720 */  VPst,  VPst,  VAbv,  VAbv,  VBlw,  VBlw,  VPre,  VAbv,  VBlw,  VAbv,  VAbv, VMAbv,     O,     O,     O,     O,
+  /* 11720 */  VPst,  VPst,  VAbv,  VAbv,  VBlw,  VBlw,  VPre,  VAbv,  VBlw,  VAbv,  VAbv,  VAbv,     O,     O,     O,     O,
   /* 11730 */     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     O,     O,     O,     O,
 
 #define use_offset_0x11800u 5848
@@ -1066,7 +1067,7 @@ static const USE_TABLE_ELEMENT_TYPE use_table[] = {
 
 }; /* Table items: 8824; occupancy: 79% */
 
-USE_TABLE_ELEMENT_TYPE
+static inline uint8_t
 hb_use_get_category (hb_codepoint_t u)
 {
   switch (u >> 12)
@@ -1154,7 +1155,7 @@ hb_use_get_category (hb_codepoint_t u)
     default:
       break;
   }
-  return USE_O;
+  return USE(O);
 }
 
 #undef B
@@ -1198,5 +1199,5 @@ hb_use_get_category (hb_codepoint_t u)
 #undef VMPre
 
 
-#endif
+#endif /* HB_OT_SHAPE_COMPLEX_USE_TABLE_HH */
 /* == End of generated table == */
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-use.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-use.cc
index 8ac569d8bf..0d0b7e771e 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-use.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-use.cc
@@ -30,14 +30,12 @@
 
 #ifndef HB_NO_OT_SHAPE
 
-#include "hb-ot-shape-complex-use.hh"
+#include "hb-ot-shape-complex-use-machine.hh"
+#include "hb-ot-shape-complex-use-table.hh"
 #include "hb-ot-shape-complex-arabic.hh"
 #include "hb-ot-shape-complex-arabic-joining-list.hh"
 #include "hb-ot-shape-complex-vowel-constraints.hh"
 
-/* buffer var allocations */
-#define use_category() complex_var_u8_1()
-
 
 /*
  * Universal Shaping Engine.
@@ -69,11 +67,11 @@ use_topographical_features[] =
 };
 /* Same order as use_topographical_features. */
 enum joining_form_t {
-  USE_ISOL,
-  USE_INIT,
-  USE_MEDI,
-  USE_FINA,
-  _USE_NONE
+  JOINING_FORM_ISOL,
+  JOINING_FORM_INIT,
+  JOINING_FORM_MEDI,
+  JOINING_FORM_FINA,
+  _JOINING_FORM_NONE
 };
 static const hb_tag_t
 use_other_features[] =
@@ -186,22 +184,6 @@ data_destroy_use (void *data)
   free (data);
 }
 
-enum use_syllable_type_t {
-  use_independent_cluster,
-  use_virama_terminated_cluster,
-  use_sakot_terminated_cluster,
-  use_standard_cluster,
-  use_number_joiner_terminated_cluster,
-  use_numeral_cluster,
-  use_symbol_cluster,
-  use_hieroglyph_cluster,
-  use_broken_cluster,
-  use_non_cluster,
-};
-
-#include "hb-ot-shape-complex-use-machine.hh"
-
-
 static void
 setup_masks_use (const hb_ot_shape_plan_t *plan,
 		 hb_buffer_t              *buffer,
@@ -239,7 +221,7 @@ setup_rphf_mask (const hb_ot_shape_plan_t *plan,
 
   foreach_syllable (buffer, start, end)
   {
-    unsigned int limit = info[start].use_category() == USE_R ? 1 : hb_min (3u, end - start);
+    unsigned int limit = info[start].use_category() == USE(R) ? 1 : hb_min (3u, end - start);
     for (unsigned int i = start; i < start + limit; i++)
       info[i].mask |= mask;
   }
@@ -253,7 +235,7 @@ setup_topographical_masks (const hb_ot_shape_plan_t *plan,
   if (use_plan->arabic_plan)
     return;
 
-  static_assert ((USE_INIT < 4 && USE_ISOL < 4 && USE_MEDI < 4 && USE_FINA < 4), "");
+  static_assert ((JOINING_FORM_INIT < 4 && JOINING_FORM_ISOL < 4 && JOINING_FORM_MEDI < 4 && JOINING_FORM_FINA < 4), "");
   hb_mask_t masks[4], all_masks = 0;
   for (unsigned int i = 0; i < 4; i++)
   {
@@ -267,7 +249,7 @@ setup_topographical_masks (const hb_ot_shape_plan_t *plan,
   hb_mask_t other_masks = ~all_masks;
 
   unsigned int last_start = 0;
-  joining_form_t last_form = _USE_NONE;
+  joining_form_t last_form = _JOINING_FORM_NONE;
   hb_glyph_info_t *info = buffer->info;
   foreach_syllable (buffer, start, end)
   {
@@ -279,7 +261,7 @@ setup_topographical_masks (const hb_ot_shape_plan_t *plan,
       case use_hieroglyph_cluster:
       case use_non_cluster:
 	/* These don't join.  Nothing to do. */
-	last_form = _USE_NONE;
+	last_form = _JOINING_FORM_NONE;
 	break;
 
       case use_virama_terminated_cluster:
@@ -289,18 +271,18 @@ setup_topographical_masks (const hb_ot_shape_plan_t *plan,
       case use_numeral_cluster:
       case use_broken_cluster:
 
-	bool join = last_form == USE_FINA || last_form == USE_ISOL;
+	bool join = last_form == JOINING_FORM_FINA || last_form == JOINING_FORM_ISOL;
 
 	if (join)
 	{
 	  /* Fixup previous syllable's form. */
-	  last_form = last_form == USE_FINA ? USE_MEDI : USE_INIT;
+	  last_form = last_form == JOINING_FORM_FINA ? JOINING_FORM_MEDI : JOINING_FORM_INIT;
 	  for (unsigned int i = last_start; i < start; i++)
 	    info[i].mask = (info[i].mask & other_masks) | masks[last_form];
 	}
 
 	/* Form for this syllable. */
-	last_form = join ? USE_FINA : USE_ISOL;
+	last_form = join ? JOINING_FORM_FINA : JOINING_FORM_ISOL;
 	for (unsigned int i = start; i < end; i++)
 	  info[i].mask = (info[i].mask & other_masks) | masks[last_form];
 
@@ -336,11 +318,11 @@ record_rphf_use (const hb_ot_shape_plan_t *plan,
 
   foreach_syllable (buffer, start, end)
   {
-    /* Mark a substituted repha as USE_R. */
+    /* Mark a substituted repha as USE(R). */
     for (unsigned int i = start; i < end && (info[i].mask & mask); i++)
       if (_hb_glyph_info_substituted (&info[i]))
       {
-	info[i].use_category() = USE_R;
+	info[i].use_category() = USE(R);
 	break;
       }
   }
@@ -359,7 +341,7 @@ record_pref_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
     for (unsigned int i = start; i < end; i++)
       if (_hb_glyph_info_substituted (&info[i]))
       {
-	info[i].use_category() = USE_VPre;
+	info[i].use_category() = USE(VPre);
 	break;
       }
   }
@@ -368,7 +350,7 @@ record_pref_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
 static inline bool
 is_halant_use (const hb_glyph_info_t &info)
 {
-  return (info.use_category() == USE_H || info.use_category() == USE_HVM) &&
+  return (info.use_category() == USE(H) || info.use_category() == USE(HVM)) &&
 	 !_hb_glyph_info_ligated (&info);
 }
 
@@ -387,24 +369,24 @@ reorder_syllable_use (hb_buffer_t *buffer, unsigned int start, unsigned int end)
 
   hb_glyph_info_t *info = buffer->info;
 
-#define POST_BASE_FLAGS64 (FLAG64 (USE_FAbv) | \
-			   FLAG64 (USE_FBlw) | \
-			   FLAG64 (USE_FPst) | \
-			   FLAG64 (USE_MAbv) | \
-			   FLAG64 (USE_MBlw) | \
-			   FLAG64 (USE_MPst) | \
-			   FLAG64 (USE_MPre) | \
-			   FLAG64 (USE_VAbv) | \
-			   FLAG64 (USE_VBlw) | \
-			   FLAG64 (USE_VPst) | \
-			   FLAG64 (USE_VPre) | \
-			   FLAG64 (USE_VMAbv) | \
-			   FLAG64 (USE_VMBlw) | \
-			   FLAG64 (USE_VMPst) | \
-			   FLAG64 (USE_VMPre))
+#define POST_BASE_FLAGS64 (FLAG64 (USE(FAbv)) | \
+			   FLAG64 (USE(FBlw)) | \
+			   FLAG64 (USE(FPst)) | \
+			   FLAG64 (USE(MAbv)) | \
+			   FLAG64 (USE(MBlw)) | \
+			   FLAG64 (USE(MPst)) | \
+			   FLAG64 (USE(MPre)) | \
+			   FLAG64 (USE(VAbv)) | \
+			   FLAG64 (USE(VBlw)) | \
+			   FLAG64 (USE(VPst)) | \
+			   FLAG64 (USE(VPre)) | \
+			   FLAG64 (USE(VMAbv)) | \
+			   FLAG64 (USE(VMBlw)) | \
+			   FLAG64 (USE(VMPst)) | \
+			   FLAG64 (USE(VMPre)))
 
   /* Move things forward. */
-  if (info[start].use_category() == USE_R && end - start > 1)
+  if (info[start].use_category() == USE(R) && end - start > 1)
   {
     /* Got a repha.  Reorder it towards the end, but before the first post-base
      * glyph. */
@@ -441,7 +423,7 @@ reorder_syllable_use (hb_buffer_t *buffer, unsigned int start, unsigned int end)
        * shift things in between forward. */
       j = i + 1;
     }
-    else if (((flag) & (FLAG (USE_VPre) | FLAG (USE_VMPre))) &&
+    else if (((flag) & (FLAG (USE(VPre)) | FLAG (USE(VMPre)))) &&
 	     /* Only move the first component of a MultipleSubst. */
 	     0 == _hb_glyph_info_get_lig_comp (&info[i]) &&
 	     j < i)
@@ -454,76 +436,22 @@ reorder_syllable_use (hb_buffer_t *buffer, unsigned int start, unsigned int end)
   }
 }
 
-static inline void
-insert_dotted_circles_use (const hb_ot_shape_plan_t *plan HB_UNUSED,
-			   hb_font_t *font,
-			   hb_buffer_t *buffer)
-{
-  if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
-    return;
-
-  /* Note: This loop is extra overhead, but should not be measurable.
-   * TODO Use a buffer scratch flag to remove the loop. */
-  bool has_broken_syllables = false;
-  unsigned int count = buffer->len;
-  hb_glyph_info_t *info = buffer->info;
-  for (unsigned int i = 0; i < count; i++)
-    if ((info[i].syllable() & 0x0F) == use_broken_cluster)
-    {
-      has_broken_syllables = true;
-      break;
-    }
-  if (likely (!has_broken_syllables))
-    return;
-
-  hb_glyph_info_t dottedcircle = {0};
-  if (!font->get_nominal_glyph (0x25CCu, &dottedcircle.codepoint))
-    return;
-  dottedcircle.use_category() = hb_use_get_category (0x25CC);
-
-  buffer->clear_output ();
-
-  buffer->idx = 0;
-  unsigned int last_syllable = 0;
-  while (buffer->idx < buffer->len && buffer->successful)
-  {
-    unsigned int syllable = buffer->cur().syllable();
-    use_syllable_type_t syllable_type = (use_syllable_type_t) (syllable & 0x0F);
-    if (unlikely (last_syllable != syllable && syllable_type == use_broken_cluster))
-    {
-      last_syllable = syllable;
-
-      hb_glyph_info_t ginfo = dottedcircle;
-      ginfo.cluster = buffer->cur().cluster;
-      ginfo.mask = buffer->cur().mask;
-      ginfo.syllable() = buffer->cur().syllable();
-
-      /* Insert dottedcircle after possible Repha. */
-      while (buffer->idx < buffer->len && buffer->successful &&
-	     last_syllable == buffer->cur().syllable() &&
-	     buffer->cur().use_category() == USE_R)
-	buffer->next_glyph ();
-
-      buffer->output_info (ginfo);
-    }
-    else
-      buffer->next_glyph ();
-  }
-  buffer->swap_buffers ();
-}
-
 static void
 reorder_use (const hb_ot_shape_plan_t *plan,
 	     hb_font_t *font,
 	     hb_buffer_t *buffer)
 {
-	if (buffer->message (font, "start reordering USE")) {
-	  insert_dotted_circles_use (plan, font, buffer);
+  if (buffer->message (font, "start reordering USE"))
+  {
+    hb_syllabic_insert_dotted_circles (font, buffer,
+				       use_broken_cluster,
+				       USE(B),
+				       USE(R));
 
-	  foreach_syllable (buffer, start, end)
-	    reorder_syllable_use (buffer, start, end);
+    foreach_syllable (buffer, start, end)
+      reorder_syllable_use (buffer, start, end);
 
-	  (void) buffer->message (font, "end reordering USE");
+    (void) buffer->message (font, "end reordering USE");
   }
 
   HB_BUFFER_DEALLOCATE_VAR (buffer, use_category);
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-use.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-use.hh
deleted file mode 100644
index 788fb6b6ac..0000000000
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-use.hh
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- * Copyright © 2015  Mozilla Foundation.
- * Copyright © 2015  Google, Inc.
- *
- *  This is part of HarfBuzz, a text shaping library.
- *
- * Permission is hereby granted, without written agreement and without
- * license or royalty fees, to use, copy, modify, and distribute this
- * software and its documentation for any purpose, provided that the
- * above copyright notice and the following two paragraphs appear in
- * all copies of this software.
- *
- * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
- * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
- * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
- * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
- * DAMAGE.
- *
- * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
- * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
- * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
- * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
- *
- * Mozilla Author(s): Jonathan Kew
- * Google Author(s): Behdad Esfahbod
- */
-
-#ifndef HB_OT_SHAPE_COMPLEX_USE_HH
-#define HB_OT_SHAPE_COMPLEX_USE_HH
-
-#include "hb.hh"
-
-
-#include "hb-ot-shape-complex.hh"
-
-
-#define USE_TABLE_ELEMENT_TYPE uint8_t
-
-/* Cateories used in the Universal Shaping Engine spec:
- * https://docs.microsoft.com/en-us/typography/script-development/use
- */
-/* Note: This enum is duplicated in the -machine.rl source file.
- * Not sure how to avoid duplication. */
-enum use_category_t {
-  USE_O		= 0,	/* OTHER */
-
-  USE_B		= 1,	/* BASE */
-  USE_N		= 4,	/* BASE_NUM */
-  USE_GB	= 5,	/* BASE_OTHER */
-  USE_SUB	= 11,	/* CONS_SUB */
-  USE_H		= 12,	/* HALANT */
-
-  USE_HN	= 13,	/* HALANT_NUM */
-  USE_ZWNJ	= 14,	/* Zero width non-joiner */
-  USE_R		= 18,	/* REPHA */
-  USE_S		= 19,	/* SYM */
-  USE_CS	= 43,	/* CONS_WITH_STACKER */
-
-  /* https://github.com/harfbuzz/harfbuzz/issues/1102 */
-  USE_HVM	= 44,	/* HALANT_OR_VOWEL_MODIFIER */
-
-  USE_Sk	= 48,	/* SAKOT */
-  USE_G		= 49,	/* HIEROGLYPH */
-  USE_J		= 50,	/* HIEROGLYPH_JOINER */
-  USE_SB	= 51,	/* HIEROGLYPH_SEGMENT_BEGIN */
-  USE_SE	= 52,	/* HIEROGLYPH_SEGMENT_END */
-
-  USE_FAbv	= 24,	/* CONS_FINAL_ABOVE */
-  USE_FBlw	= 25,	/* CONS_FINAL_BELOW */
-  USE_FPst	= 26,	/* CONS_FINAL_POST */
-  USE_MAbv	= 27,	/* CONS_MED_ABOVE */
-  USE_MBlw	= 28,	/* CONS_MED_BELOW */
-  USE_MPst	= 29,	/* CONS_MED_POST */
-  USE_MPre	= 30,	/* CONS_MED_PRE */
-  USE_CMAbv	= 31,	/* CONS_MOD_ABOVE */
-  USE_CMBlw	= 32,	/* CONS_MOD_BELOW */
-  USE_VAbv	= 33,	/* VOWEL_ABOVE / VOWEL_ABOVE_BELOW / VOWEL_ABOVE_BELOW_POST / VOWEL_ABOVE_POST */
-  USE_VBlw	= 34,	/* VOWEL_BELOW / VOWEL_BELOW_POST */
-  USE_VPst	= 35,	/* VOWEL_POST	UIPC = Right */
-  USE_VPre	= 22,	/* VOWEL_PRE / VOWEL_PRE_ABOVE / VOWEL_PRE_ABOVE_POST / VOWEL_PRE_POST */
-  USE_VMAbv	= 37,	/* VOWEL_MOD_ABOVE */
-  USE_VMBlw	= 38,	/* VOWEL_MOD_BELOW */
-  USE_VMPst	= 39,	/* VOWEL_MOD_POST */
-  USE_VMPre	= 23,	/* VOWEL_MOD_PRE */
-  USE_SMAbv	= 41,	/* SYM_MOD_ABOVE */
-  USE_SMBlw	= 42,	/* SYM_MOD_BELOW */
-  USE_FMAbv	= 45,	/* CONS_FINAL_MOD	UIPC = Top */
-  USE_FMBlw	= 46,	/* CONS_FINAL_MOD	UIPC = Bottom */
-  USE_FMPst	= 47,	/* CONS_FINAL_MOD	UIPC = Not_Applicable */
-};
-
-HB_INTERNAL USE_TABLE_ELEMENT_TYPE
-hb_use_get_category (hb_codepoint_t u);
-
-#endif /* HB_OT_SHAPE_COMPLEX_USE_HH */
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-vowel-constraints.cc b/thirdparty/harfbuzz/src/hb-ot-shape-complex-vowel-constraints.cc
index 1af546e4fa..1037626998 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex-vowel-constraints.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-vowel-constraints.cc
@@ -23,15 +23,15 @@
 static void
 _output_dotted_circle (hb_buffer_t *buffer)
 {
-  hb_glyph_info_t &dottedcircle = buffer->output_glyph (0x25CCu);
-  _hb_glyph_info_reset_continuation (&dottedcircle);
+  (void) buffer->output_glyph (0x25CCu);
+  _hb_glyph_info_reset_continuation (&buffer->prev());
 }
 
 static void
 _output_with_dotted_circle (hb_buffer_t *buffer)
 {
   _output_dotted_circle (buffer);
-  buffer->next_glyph ();
+  (void) buffer->next_glyph ();
 }
 
 void
@@ -51,7 +51,6 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
    *
    * https://github.com/harfbuzz/harfbuzz/issues/1019
    */
-  bool processed = false;
   buffer->clear_output ();
   unsigned int count = buffer->len;
   switch ((unsigned) buffer->props.script)
@@ -97,15 +96,14 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		buffer->idx + 2 < count &&
 		0x0907u == buffer->cur (2).codepoint)
 	    {
-	      buffer->next_glyph ();
+	      (void) buffer->next_glyph ();
 	      matched = true;
 	    }
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_BENGALI:
@@ -124,10 +122,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    matched = 0x09E2u == buffer->cur (1).codepoint;
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_GURMUKHI:
@@ -161,10 +158,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    }
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_GUJARATI:
@@ -186,10 +182,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    matched = 0x0ABEu == buffer->cur (1).codepoint;
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_ORIYA:
@@ -205,10 +200,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    matched = 0x0B57u == buffer->cur (1).codepoint;
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_TAMIL:
@@ -220,10 +214,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	{
 	  matched = true;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_TELUGU:
@@ -244,10 +237,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    matched = 0x0C55u == buffer->cur (1).codepoint;
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_KANNADA:
@@ -263,10 +255,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    matched = 0x0CCCu == buffer->cur (1).codepoint;
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_MALAYALAM:
@@ -290,10 +281,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    }
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_SINHALA:
@@ -326,10 +316,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    }
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_BRAHMI:
@@ -348,10 +337,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    matched = 0x11042u == buffer->cur (1).codepoint;
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_KHUDAWADI:
@@ -370,10 +358,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    }
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_TIRHUTA:
@@ -397,10 +384,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    }
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_MODI:
@@ -418,10 +404,9 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    }
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     case HB_SCRIPT_TAKRI:
@@ -442,21 +427,15 @@ _hb_preprocess_text_vowel_constraints (const hb_ot_shape_plan_t *plan HB_UNUSED,
 	    matched = 0x116B2u == buffer->cur (1).codepoint;
 	    break;
 	}
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	if (matched) _output_with_dotted_circle (buffer);
       }
-      processed = true;
       break;
 
     default:
       break;
   }
-  if (processed)
-  {
-    if (buffer->idx < count)
-      buffer->next_glyph ();
-    buffer->swap_buffers ();
-  }
+  buffer->swap_buffers ();
 }
 
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex.hh
index a1a7a6a47b..19e24b9f30 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-complex.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex.hh
@@ -35,8 +35,8 @@
 
 
 /* buffer var allocations, used by complex shapers */
-#define complex_var_u8_0()	var2.u8[2]
-#define complex_var_u8_1()	var2.u8[3]
+#define complex_var_u8_category()	var2.u8[2]
+#define complex_var_u8_auxiliary()	var2.u8[3]
 
 
 #define HB_OT_SHAPE_COMPLEX_MAX_COMBINING_MARKS 32
@@ -186,27 +186,8 @@ hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
     case HB_SCRIPT_ARABIC:
 
     /* Unicode-3.0 additions */
-    case HB_SCRIPT_MONGOLIAN:
     case HB_SCRIPT_SYRIAC:
 
-    /* Unicode-5.0 additions */
-    case HB_SCRIPT_NKO:
-    case HB_SCRIPT_PHAGS_PA:
-
-    /* Unicode-6.0 additions */
-    case HB_SCRIPT_MANDAIC:
-
-    /* Unicode-7.0 additions */
-    case HB_SCRIPT_MANICHAEAN:
-    case HB_SCRIPT_PSALTER_PAHLAVI:
-
-    /* Unicode-9.0 additions */
-    case HB_SCRIPT_ADLAM:
-
-    /* Unicode-11.0 additions */
-    case HB_SCRIPT_HANIFI_ROHINGYA:
-    case HB_SCRIPT_SOGDIAN:
-
       /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
        * This is because we do fallback shaping for Arabic script (and not others).
        * But note that Arabic shaping is applicable only to horizontal layout; for
@@ -284,8 +265,9 @@ hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
 	return &_hb_ot_complex_shaper_myanmar;
 
 
-    /* https://github.com/harfbuzz/harfbuzz/issues/1162 */
+#define HB_SCRIPT_MYANMAR_ZAWGYI	((hb_script_t) HB_TAG ('Q','a','a','g'))
     case HB_SCRIPT_MYANMAR_ZAWGYI:
+    /* https://github.com/harfbuzz/harfbuzz/issues/1162 */
 
       return &_hb_ot_complex_shaper_myanmar_zawgyi;
 
@@ -294,7 +276,7 @@ hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
     case HB_SCRIPT_TIBETAN:
 
     /* Unicode-3.0 additions */
-    //case HB_SCRIPT_MONGOLIAN:
+    case HB_SCRIPT_MONGOLIAN:
     //case HB_SCRIPT_SINHALA:
 
     /* Unicode-3.2 additions */
@@ -315,8 +297,8 @@ hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
 
     /* Unicode-5.0 additions */
     case HB_SCRIPT_BALINESE:
-    //case HB_SCRIPT_NKO:
-    //case HB_SCRIPT_PHAGS_PA:
+    case HB_SCRIPT_NKO:
+    case HB_SCRIPT_PHAGS_PA:
 
     /* Unicode-5.1 additions */
     case HB_SCRIPT_CHAM:
@@ -337,7 +319,7 @@ hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
     /* Unicode-6.0 additions */
     case HB_SCRIPT_BATAK:
     case HB_SCRIPT_BRAHMI:
-    //case HB_SCRIPT_MANDAIC:
+    case HB_SCRIPT_MANDAIC:
 
     /* Unicode-6.1 additions */
     case HB_SCRIPT_CHAKMA:
@@ -351,10 +333,10 @@ hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
     case HB_SCRIPT_KHOJKI:
     case HB_SCRIPT_KHUDAWADI:
     case HB_SCRIPT_MAHAJANI:
-    //case HB_SCRIPT_MANICHAEAN:
+    case HB_SCRIPT_MANICHAEAN:
     case HB_SCRIPT_MODI:
     case HB_SCRIPT_PAHAWH_HMONG:
-    //case HB_SCRIPT_PSALTER_PAHLAVI:
+    case HB_SCRIPT_PSALTER_PAHLAVI:
     case HB_SCRIPT_SIDDHAM:
     case HB_SCRIPT_TIRHUTA:
 
@@ -363,7 +345,7 @@ hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
     case HB_SCRIPT_MULTANI:
 
     /* Unicode-9.0 additions */
-    //case HB_SCRIPT_ADLAM:
+    case HB_SCRIPT_ADLAM:
     case HB_SCRIPT_BHAIKSUKI:
     case HB_SCRIPT_MARCHEN:
     case HB_SCRIPT_NEWA:
@@ -376,11 +358,11 @@ hb_ot_shape_complex_categorize (const hb_ot_shape_planner_t *planner)
     /* Unicode-11.0 additions */
     case HB_SCRIPT_DOGRA:
     case HB_SCRIPT_GUNJALA_GONDI:
-    //case HB_SCRIPT_HANIFI_ROHINGYA:
+    case HB_SCRIPT_HANIFI_ROHINGYA:
     case HB_SCRIPT_MAKASAR:
     case HB_SCRIPT_MEDEFAIDRIN:
     case HB_SCRIPT_OLD_SOGDIAN:
-    //case HB_SCRIPT_SOGDIAN:
+    case HB_SCRIPT_SOGDIAN:
 
     /* Unicode-12.0 additions */
     case HB_SCRIPT_ELYMAIC:
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-normalize.cc b/thirdparty/harfbuzz/src/hb-ot-shape-normalize.cc
index 3eabae1b45..778b5b8bd8 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-normalize.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-normalize.cc
@@ -101,8 +101,9 @@ set_glyph (hb_glyph_info_t &info, hb_font_t *font)
 static inline void
 output_char (hb_buffer_t *buffer, hb_codepoint_t unichar, hb_codepoint_t glyph)
 {
+  /* This is very confusing indeed. */
   buffer->cur().glyph_index() = glyph;
-  buffer->output_glyph (unichar); /* This is very confusing indeed. */
+  (void) buffer->output_glyph (unichar);
   _hb_glyph_info_set_unicode_props (&buffer->prev(), buffer);
 }
 
@@ -110,7 +111,7 @@ static inline void
 next_char (hb_buffer_t *buffer, hb_codepoint_t glyph)
 {
   buffer->cur().glyph_index() = glyph;
-  buffer->next_glyph ();
+  (void) buffer->next_glyph ();
 }
 
 static inline void
@@ -229,30 +230,35 @@ handle_variation_selector_cluster (const hb_ot_shape_normalize_context_t *c,
       if (font->get_variation_glyph (buffer->cur().codepoint, buffer->cur(+1).codepoint, &buffer->cur().glyph_index()))
       {
 	hb_codepoint_t unicode = buffer->cur().codepoint;
-	buffer->replace_glyphs (2, 1, &unicode);
+	(void) buffer->replace_glyphs (2, 1, &unicode);
       }
       else
       {
 	/* Just pass on the two characters separately, let GSUB do its magic. */
 	set_glyph (buffer->cur(), font);
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
 	set_glyph (buffer->cur(), font);
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
       }
       /* Skip any further variation selectors. */
-      while (buffer->idx < end && unlikely (buffer->unicode->is_variation_selector (buffer->cur().codepoint)))
+      while (buffer->idx < end &&
+	     buffer->successful &&
+	     unlikely (buffer->unicode->is_variation_selector (buffer->cur().codepoint)))
       {
 	set_glyph (buffer->cur(), font);
-	buffer->next_glyph ();
+	(void) buffer->next_glyph ();
       }
-    } else {
+    }
+    else
+    {
       set_glyph (buffer->cur(), font);
-      buffer->next_glyph ();
+      (void) buffer->next_glyph ();
     }
   }
-  if (likely (buffer->idx < end)) {
+  if (likely (buffer->idx < end))
+  {
     set_glyph (buffer->cur(), font);
-    buffer->next_glyph ();
+    (void) buffer->next_glyph ();
   }
 }
 
@@ -348,7 +354,7 @@ _hb_ot_shape_normalize (const hb_ot_shape_plan_t *plan,
 						      sizeof (buffer->info[0]),
 						      &buffer->cur().glyph_index(),
 						      sizeof (buffer->info[0]));
-	buffer->next_glyphs (done);
+	if (unlikely (!buffer->next_glyphs (done))) break;
       }
       while (buffer->idx < end && buffer->successful)
 	decompose_current_character (&c, might_short_circuit);
@@ -419,6 +425,7 @@ _hb_ot_shape_normalize (const hb_ot_shape_plan_t *plan,
   /* Third round, recompose */
 
   if (!all_simple &&
+      buffer->successful &&
       (mode == HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS ||
        mode == HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT))
   {
@@ -428,8 +435,8 @@ _hb_ot_shape_normalize (const hb_ot_shape_plan_t *plan,
     buffer->clear_output ();
     count = buffer->len;
     unsigned int starter = 0;
-    buffer->next_glyph ();
-    while (buffer->idx < count && buffer->successful)
+    (void) buffer->next_glyph ();
+    while (buffer->idx < count /* No need for: && buffer->successful */)
     {
       hb_codepoint_t composed, glyph;
       if (/* We don't try to compose a non-mark character with it's preceding starter.
@@ -451,9 +458,7 @@ _hb_ot_shape_normalize (const hb_ot_shape_plan_t *plan,
 	    font->get_nominal_glyph (composed, &glyph))
 	{
 	  /* Composes. */
-	  buffer->next_glyph (); /* Copy to out-buffer. */
-	  if (unlikely (!buffer->successful))
-	    return;
+	  if (unlikely (!buffer->next_glyph ())) break; /* Copy to out-buffer. */
 	  buffer->merge_out_clusters (starter, buffer->out_len);
 	  buffer->out_len--; /* Remove the second composable. */
 	  /* Modify starter and carry on. */
@@ -466,7 +471,7 @@ _hb_ot_shape_normalize (const hb_ot_shape_plan_t *plan,
       }
 
       /* Blocked, or doesn't compose. */
-      buffer->next_glyph ();
+      if (unlikely (!buffer->next_glyph ())) break;
 
       if (info_cc (buffer->prev()) == 0)
 	starter = buffer->out_len - 1;
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape.cc b/thirdparty/harfbuzz/src/hb-ot-shape.cc
index 7d90558458..86ab0b4268 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape.cc
@@ -534,9 +534,7 @@ hb_insert_dotted_circle (hb_buffer_t *buffer, hb_font_t *font)
   hb_glyph_info_t info = dottedcircle;
   info.cluster = buffer->cur().cluster;
   info.mask = buffer->cur().mask;
-  buffer->output_info (info);
-  while (buffer->idx < buffer->len && buffer->successful)
-    buffer->next_glyph ();
+  (void) buffer->output_info (info);
   buffer->swap_buffers ();
 }
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape.h b/thirdparty/harfbuzz/src/hb-ot-shape.h
index 7b1bcc0637..afdff72833 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape.h
+++ b/thirdparty/harfbuzz/src/hb-ot-shape.h
@@ -24,7 +24,7 @@
  * Red Hat Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-tag-table.hh b/thirdparty/harfbuzz/src/hb-ot-tag-table.hh
index f1c391cf0e..87830b5462 100644
--- a/thirdparty/harfbuzz/src/hb-ot-tag-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-tag-table.hh
@@ -6,8 +6,8 @@
  *
  * on files with these headers:
  *
- * <meta name="updated_at" content="2020-11-17 08:21 AM" />
- * File-Date: 2020-09-29
+ * <meta name="updated_at" content="2021-02-12 04:08 PM" />
+ * File-Date: 2021-03-05
  */
 
 #ifndef HB_OT_TAG_TABLE_HH
@@ -169,6 +169,7 @@ static const LangTag ot_languages[] = {
   {"bko",	HB_TAG('B','M','L',' ')},	/* Kwa' -> Bamileke */
   {"bla",	HB_TAG('B','K','F',' ')},	/* Siksika -> Blackfoot */
   {"ble",	HB_TAG('B','L','N',' ')},	/* Balanta-Kentohe -> Balante */
+  {"blg",	HB_TAG('I','B','A',' ')},	/* Balau (retired code) -> Iban */
   {"bli",	HB_TAG_NONE	       },	/* Bolia != Baluchi */
   {"blk",	HB_TAG('B','L','K',' ')},	/* Pa’o Karen */
   {"blk",	HB_TAG('K','R','N',' ')},	/* Pa'o Karen -> Karen */
@@ -358,6 +359,7 @@ static const LangTag ot_languages[] = {
   {"czo",	HB_TAG('Z','H','S',' ')},	/* Min Zhong Chinese -> Chinese, Simplified */
   {"czt",	HB_TAG('Q','I','N',' ')},	/* Zotung Chin -> Chin */
   {"da",	HB_TAG('D','A','N',' ')},	/* Danish */
+/*{"dag",	HB_TAG('D','A','G',' ')},*/	/* Dagbani */
   {"dao",	HB_TAG('Q','I','N',' ')},	/* Daai Chin -> Chin */
   {"dap",	HB_TAG('N','I','S',' ')},	/* Nisi (India) (retired code) */
 /*{"dar",	HB_TAG('D','A','R',' ')},*/	/* Dargwa */
@@ -834,6 +836,7 @@ static const LangTag ot_languages[] = {
   {"lri",	HB_TAG('L','U','H',' ')},	/* Marachi -> Luyia */
   {"lrm",	HB_TAG('L','U','H',' ')},	/* Marama -> Luyia */
   {"lrt",	HB_TAG('C','P','P',' ')},	/* Larantuka Malay -> Creoles */
+  {"lsb",	HB_TAG_NONE	       },	/* Burundian Sign Language != Lower Sorbian */
   {"lsm",	HB_TAG('L','U','H',' ')},	/* Saamia -> Luyia */
   {"lt",	HB_TAG('L','T','H',' ')},	/* Lithuanian */
   {"ltg",	HB_TAG('L','V','I',' ')},	/* Latgalian -> Latvian */
@@ -990,7 +993,7 @@ static const LangTag ot_languages[] = {
 /*{"nga",	HB_TAG('N','G','A',' ')},*/	/* Ngbaka */
   {"ngl",	HB_TAG('L','M','W',' ')},	/* Lomwe */
   {"ngm",	HB_TAG('C','P','P',' ')},	/* Ngatik Men's Creole -> Creoles */
-  {"ngo",	HB_TAG('S','X','T',' ')},	/* Ngoni -> Sutu */
+  {"ngo",	HB_TAG('S','X','T',' ')},	/* Ngoni (retired code) -> Sutu */
   {"ngr",	HB_TAG_NONE	       },	/* Engdewu != Nagari */
   {"ngu",	HB_TAG('N','A','H',' ')},	/* Guerrero Nahuatl -> Nahuatl */
   {"nhc",	HB_TAG('N','A','H',' ')},	/* Tabasco Nahuatl -> Nahuatl */
@@ -1520,6 +1523,8 @@ static const LangTag ot_languages[] = {
   {"xmm",	HB_TAG('C','P','P',' ')},	/* Manado Malay -> Creoles */
   {"xmv",	HB_TAG('M','L','G',' ')},	/* Antankarana Malagasy -> Malagasy */
   {"xmw",	HB_TAG('M','L','G',' ')},	/* Tsimihety Malagasy -> Malagasy */
+  {"xnj",	HB_TAG('S','X','T',' ')},	/* Ngoni (Tanzania) -> Sutu */
+  {"xnq",	HB_TAG('S','X','T',' ')},	/* Ngoni (Mozambique) -> Sutu */
   {"xnr",	HB_TAG('D','G','R',' ')},	/* Kangri -> Dogri (macrolanguage) */
 /*{"xog",	HB_TAG('X','O','G',' ')},*/	/* Soga */
   {"xpe",	HB_TAG('X','P','E',' ')},	/* Liberia Kpelle -> Kpelle (Liberia) */
@@ -2808,6 +2813,8 @@ hb_ot_ambiguous_tag_to_language (hb_tag_t tag)
     return hb_language_from_string ("hnd", -1);  /* Southern Hindko */
   case HB_TAG('H','Y','E',' '):  /* Armenian */
     return hb_language_from_string ("hyw", -1);  /* Western Armenian */
+  case HB_TAG('I','B','A',' '):  /* Iban */
+    return hb_language_from_string ("iba", -1);  /* Iban */
   case HB_TAG('I','J','O',' '):  /* Ijo */
     return hb_language_from_string ("ijo", -1);  /* Ijo [family] */
   case HB_TAG('I','N','U',' '):  /* Inuktitut */
@@ -2892,6 +2899,8 @@ hb_ot_ambiguous_tag_to_language (hb_tag_t tag)
     return hb_language_from_string ("sq", -1);  /* Albanian [macrolanguage] */
   case HB_TAG('S','R','B',' '):  /* Serbian */
     return hb_language_from_string ("sr", -1);  /* Serbian */
+  case HB_TAG('S','X','T',' '):  /* Sutu */
+    return hb_language_from_string ("xnj", -1);  /* Ngoni (Tanzania) */
   case HB_TAG('S','Y','R',' '):  /* Syriac */
     return hb_language_from_string ("syr", -1);  /* Syriac [macrolanguage] */
   case HB_TAG('S','Y','R','E'):  /* Syriac, Estrangela script-variant (equivalent to ISO 15924 'Syre') */
diff --git a/thirdparty/harfbuzz/src/hb-ot-tag.cc b/thirdparty/harfbuzz/src/hb-ot-tag.cc
index 19bd3639d3..fc145a41f7 100644
--- a/thirdparty/harfbuzz/src/hb-ot-tag.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-tag.cc
@@ -164,6 +164,15 @@ hb_ot_all_tags_from_script (hb_script_t   script,
   *count = i;
 }
 
+/**
+ * hb_ot_tag_to_script:
+ * @tag: a script tag
+ *
+ * Converts a script tag to an #hb_script_t.
+ *
+ * Return value: The #hb_script_t corresponding to @tag.
+ *
+ **/
 hb_script_t
 hb_ot_tag_to_script (hb_tag_t tag)
 {
@@ -351,13 +360,13 @@ parse_private_use_subtag (const char     *private_use_subtag,
  * hb_ot_tags_from_script_and_language:
  * @script: an #hb_script_t to convert.
  * @language: an #hb_language_t to convert.
- * @script_count: (allow-none): maximum number of script tags to retrieve (IN)
+ * @script_count: (inout) (optional): maximum number of script tags to retrieve (IN)
  * and actual number of script tags retrieved (OUT)
- * @script_tags: (out) (allow-none): array of size at least @script_count to store the
+ * @script_tags: (out) (optional): array of size at least @script_count to store the
  * script tag results
- * @language_count: (allow-none): maximum number of language tags to retrieve
+ * @language_count: (inout) (optional): maximum number of language tags to retrieve
  * (IN) and actual number of language tags retrieved (OUT)
- * @language_tags: (out) (allow-none): array of size at least @language_count to store
+ * @language_tags: (out) (optional): array of size at least @language_count to store
  * the language tag results
  *
  * Converts an #hb_script_t and an #hb_language_t to script and language tags.
@@ -424,10 +433,12 @@ hb_ot_tags_from_script_and_language (hb_script_t   script,
 
 /**
  * hb_ot_tag_to_language:
+ * @tag: an language tag
  *
+ * Converts a language tag to an #hb_language_t.
  *
- *
- * Return value: (transfer none):
+ * Return value: (transfer none) (nullable):
+ * The #hb_language_t corresponding to @tag.
  *
  * Since: 0.9.2
  **/
@@ -478,9 +489,9 @@ hb_ot_tag_to_language (hb_tag_t tag)
  * hb_ot_tags_to_script_and_language:
  * @script_tag: a script tag
  * @language_tag: a language tag
- * @script: (allow-none): the #hb_script_t corresponding to @script_tag (OUT).
- * @language: (allow-none): the #hb_language_t corresponding to @script_tag and
- * @language_tag (OUT).
+ * @script: (out) (optional): the #hb_script_t corresponding to @script_tag.
+ * @language: (out) (optional): the #hb_language_t corresponding to @script_tag and
+ * @language_tag.
  *
  * Converts a script tag and a language tag to an #hb_script_t and an
  * #hb_language_t.
diff --git a/thirdparty/harfbuzz/src/hb-ot-var-gvar-table.hh b/thirdparty/harfbuzz/src/hb-ot-var-gvar-table.hh
index 4d4e6dcae4..7e4eaaad95 100644
--- a/thirdparty/harfbuzz/src/hb-ot-var-gvar-table.hh
+++ b/thirdparty/harfbuzz/src/hb-ot-var-gvar-table.hh
@@ -652,8 +652,8 @@ no_more_gaps:
 	/* apply specified / inferred deltas to points */
 	for (unsigned int i = 0; i < points.length; i++)
 	{
-	  points[i].x += roundf (deltas[i].x);
-	  points[i].y += roundf (deltas[i].y);
+	  points[i].x += deltas[i].x;
+	  points[i].y += deltas[i].y;
 	}
       } while (iterator.move_to_next ());
 
diff --git a/thirdparty/harfbuzz/src/hb-ot-var.cc b/thirdparty/harfbuzz/src/hb-ot-var.cc
index 1fe57383c0..6b42b45cd9 100644
--- a/thirdparty/harfbuzz/src/hb-ot-var.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-var.cc
@@ -56,7 +56,7 @@
  *
  * Tests whether a face includes any OpenType variation data in the `fvar` table.
  *
- * Return value: true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 1.4.2
  **/
@@ -87,7 +87,7 @@ hb_ot_var_get_axis_count (hb_face_t *face)
  * hb_ot_var_get_axes:
  * @face: #hb_face_t to work upon
  * @start_offset: offset of the first lookup to retrieve
- * @axes_count: (inout) (allow-none): Input = the maximum number of variation axes to return;
+ * @axes_count: (inout) (optional): Input = the maximum number of variation axes to return;
  *                Output = the actual number of variation axes returned (may be zero)
  * @axes_array: (out caller-allocates) (array length=axes_count): The array of variation axes found
  *
@@ -133,7 +133,7 @@ hb_ot_var_find_axis (hb_face_t        *face,
  * hb_ot_var_get_axis_infos:
  * @face: #hb_face_t to work upon
  * @start_offset: offset of the first lookup to retrieve
- * @axes_count: (inout) (allow-none): Input = the maximum number of variation axes to return;
+ * @axes_count: (inout) (optional): Input = the maximum number of variation axes to return;
  *                Output = the actual number of variation axes returned (may be zero)
  * @axes_array: (out caller-allocates) (array length=axes_count): The array of variation axes found
  *
@@ -162,7 +162,7 @@ hb_ot_var_get_axis_infos (hb_face_t             *face,
  * Fetches the variation-axis information corresponding to the specified axis tag
  * in the specified face.
  *
- * Return value: true if data found, false otherwise
+ * Return value: %true if data found, %false otherwise
  *
  * Since: 2.2.0
  **/
@@ -237,7 +237,7 @@ hb_ot_var_named_instance_get_postscript_name_id (hb_face_t  *face,
  * hb_ot_var_named_instance_get_design_coords:
  * @face: The #hb_face_t to work on
  * @instance_index: The index of the named instance to query
- * @coords_length: (inout) (allow-none): Input = the maximum number of coordinates to return;
+ * @coords_length: (inout) (optional): Input = the maximum number of coordinates to return;
  *                 Output = the actual number of coordinates returned (may be zero)
  * @coords: (out) (array length=coords_length): The array of coordinates found for the query
  *
diff --git a/thirdparty/harfbuzz/src/hb-ot-var.h b/thirdparty/harfbuzz/src/hb-ot-var.h
index ef2ca0a716..ce201d3b4f 100644
--- a/thirdparty/harfbuzz/src/hb-ot-var.h
+++ b/thirdparty/harfbuzz/src/hb-ot-var.h
@@ -24,7 +24,7 @@
  * Red Hat Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_OT_H_IN
+#if !defined(HB_OT_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb-ot.h> instead."
 #endif
 
@@ -36,34 +36,38 @@
 HB_BEGIN_DECLS
 
 /**
- * hb_tag_t:
- * @HB_OT_TAG_VAR_AXIS_ITALIC: Registered tag for the roman/italic axis
+ * HB_OT_TAG_VAR_AXIS_ITALIC:
+ *
+ * Registered tag for the roman/italic axis.
  */
 #define HB_OT_TAG_VAR_AXIS_ITALIC	HB_TAG('i','t','a','l')
 
 /**
- * hb_tag_t:
- * @HB_OT_TAG_VAR_AXIS_OPTICAL_SIZE: Registered tag for the optical-size axis
+ * HB_OT_TAG_VAR_AXIS_OPTICAL_SIZE:
  *
+ * Registered tag for the optical-size axis.
  * <note>Note: The optical-size axis supersedes the OpenType `size` feature.</note>
  */
 #define HB_OT_TAG_VAR_AXIS_OPTICAL_SIZE	HB_TAG('o','p','s','z')
 
 /**
- * hb_tag_t:
- * @HB_OT_TAG_VAR_AXIS_SLANT: Registered tag for the slant axis
+ * HB_OT_TAG_VAR_AXIS_SLANT:
+ *
+ * Registered tag for the slant axis
  */
 #define HB_OT_TAG_VAR_AXIS_SLANT	HB_TAG('s','l','n','t')
 
 /**
- * hb_tag_t:
- * @HB_OT_TAG_VAR_AXIS_WIDTH: Registered tag for the width axis
+ * HB_OT_TAG_VAR_AXIS_WIDTH:
+ *
+ * Registered tag for the width axis.
  */
 #define HB_OT_TAG_VAR_AXIS_WIDTH	HB_TAG('w','d','t','h')
 
 /**
- * hb_tag_t:
- * @HB_OT_TAG_VAR_AXIS_WEIGHT: Registered tag for the weight axis
+ * HB_OT_TAG_VAR_AXIS_WEIGHT:
+ *
+ * Registered tag for the weight axis.
  */
 #define HB_OT_TAG_VAR_AXIS_WEIGHT	HB_TAG('w','g','h','t')
 
@@ -88,11 +92,14 @@ hb_ot_var_get_axis_count (hb_face_t *face);
  * hb_ot_var_axis_flags_t:
  * @HB_OT_VAR_AXIS_FLAG_HIDDEN: The axis should not be exposed directly in user interfaces.
  *
+ * Flags for #hb_ot_var_axis_info_t.
+ *
  * Since: 2.2.0
  */
 typedef enum { /*< flags >*/
   HB_OT_VAR_AXIS_FLAG_HIDDEN	= 0x00000001u,
 
+  /*< private >*/
   _HB_OT_VAR_AXIS_FLAG_MAX_VALUE= HB_TAG_MAX_SIGNED /*< skip >*/
 } hb_ot_var_axis_flags_t;
 
diff --git a/thirdparty/harfbuzz/src/hb-sanitize.hh b/thirdparty/harfbuzz/src/hb-sanitize.hh
index 024b4d1c99..1675e8448a 100644
--- a/thirdparty/harfbuzz/src/hb-sanitize.hh
+++ b/thirdparty/harfbuzz/src/hb-sanitize.hh
@@ -73,7 +73,7 @@
  * === The sanitize() contract ===
  *
  * The sanitize() method of each object type shall return true if it's safe to
- * call other methods of the object, and false otherwise.
+ * call other methods of the object, and %false otherwise.
  *
  * Note that what sanitize() checks for might align with what the specification
  * describes as valid table data, but does not have to be.  In particular, we
@@ -113,8 +113,8 @@
 #ifndef HB_SANITIZE_MAX_OPS_MAX
 #define HB_SANITIZE_MAX_OPS_MAX 0x3FFFFFFF
 #endif
-#ifndef HB_SANITIZE_MAX_SUTABLES
-#define HB_SANITIZE_MAX_SUTABLES 0x4000
+#ifndef HB_SANITIZE_MAX_SUBTABLES
+#define HB_SANITIZE_MAX_SUBTABLES 0x4000
 #endif
 
 struct hb_sanitize_context_t :
@@ -139,7 +139,7 @@ struct hb_sanitize_context_t :
   bool visit_subtables (unsigned count)
   {
     max_subtables += count;
-    return max_subtables < HB_SANITIZE_MAX_SUTABLES;
+    return max_subtables < HB_SANITIZE_MAX_SUBTABLES;
   }
 
   private:
diff --git a/thirdparty/harfbuzz/src/hb-serialize.hh b/thirdparty/harfbuzz/src/hb-serialize.hh
index 4566153a59..fe29bdf96e 100644
--- a/thirdparty/harfbuzz/src/hb-serialize.hh
+++ b/thirdparty/harfbuzz/src/hb-serialize.hh
@@ -256,10 +256,11 @@ struct hb_serialize_context_t
 
     packed.push (obj);
 
-    if (unlikely (packed.in_error ())) {
-      // obj wasn't successfully added to packed, so clean it up otherwise it's
-      // links will be leaked.
-      propagate_error (packed);
+    if (unlikely (!propagate_error (packed)))
+    {
+      /* Obj wasn't successfully added to packed, so clean it up otherwise its
+       * links will be leaked. When we use constructor/destructors properly, we
+       * can remove these. */
       obj->fini ();
       return 0;
     }
@@ -523,7 +524,7 @@ struct hb_serialize_context_t
   template <typename T>
   void assign_offset (const object_t* parent, const object_t::link_t &link, unsigned offset)
   {
-    auto &off = * ((BEInt<T, sizeof (T)> *) (parent->head + link.position));
+    auto &off = * ((BEInt<T> *) (parent->head + link.position));
     assert (0 == off);
     check_assign (off, offset);
   }
diff --git a/thirdparty/harfbuzz/src/hb-set.cc b/thirdparty/harfbuzz/src/hb-set.cc
index 3b4059ad32..86bf70034c 100644
--- a/thirdparty/harfbuzz/src/hb-set.cc
+++ b/thirdparty/harfbuzz/src/hb-set.cc
@@ -117,7 +117,7 @@ hb_set_destroy (hb_set_t *set)
  * @set: A set
  * @key: The user-data key to set
  * @data: A pointer to the user data to set
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the specified set.
@@ -162,7 +162,7 @@ hb_set_get_user_data (hb_set_t           *set,
  *
  * Tests whether memory allocation for a set was successful.
  *
- * Return value: %true if allocation succeeded, false otherwise
+ * Return value: %true if allocation succeeded, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -183,6 +183,9 @@ hb_set_allocation_successful (const hb_set_t  *set)
 void
 hb_set_clear (hb_set_t *set)
 {
+  if (unlikely (hb_object_is_immutable (set)))
+    return;
+
   set->clear ();
 }
 
@@ -209,7 +212,7 @@ hb_set_is_empty (const hb_set_t *set)
  *
  * Tests whether @codepoint belongs to @set.
  *
- * Return value: %true if @codepoint is in @set, false otherwise
+ * Return value: %true if @codepoint is in @set, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -298,7 +301,7 @@ hb_set_del_range (hb_set_t       *set,
  * Tests whether @set and @other are equal (contain the same
  * elements).
  *
- * Return value: %TRUE if the two sets are equal, %FALSE otherwise.
+ * Return value: %true if the two sets are equal, %false otherwise.
  *
  * Since: 0.9.7
  **/
@@ -316,7 +319,7 @@ hb_set_is_equal (const hb_set_t *set,
  *
  * Tests whether @set is a subset of @larger_set.
  *
- * Return value: %TRUE if the @set is a subset of (or equal to) @larger_set, %FALSE otherwise.
+ * Return value: %true if the @set is a subset of (or equal to) @larger_set, %false otherwise.
  *
  * Since: 1.8.1
  **/
@@ -447,7 +450,7 @@ hb_set_get_population (const hb_set_t *set)
  *
  * Finds the smallest element in the set.
  *
- * Return value: minimum of @set, or %HB_SET_VALUE_INVALID if @set is empty.
+ * Return value: minimum of @set, or #HB_SET_VALUE_INVALID if @set is empty.
  *
  * Since: 0.9.7
  **/
@@ -463,7 +466,7 @@ hb_set_get_min (const hb_set_t *set)
  *
  * Finds the largest element in the set.
  *
- * Return value: maximum of @set, or %HB_SET_VALUE_INVALID if @set is empty.
+ * Return value: maximum of @set, or #HB_SET_VALUE_INVALID if @set is empty.
  *
  * Since: 0.9.7
  **/
@@ -481,9 +484,9 @@ hb_set_get_max (const hb_set_t *set)
  *
  * Fetches the next element in @set that is greater than current value of @codepoint.
  *
- * Set @codepoint to %HB_SET_VALUE_INVALID to get started.
+ * Set @codepoint to #HB_SET_VALUE_INVALID to get started.
  *
- * Return value: %true if there was a next value, false otherwise
+ * Return value: %true if there was a next value, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -502,9 +505,9 @@ hb_set_next (const hb_set_t *set,
  *
  * Fetches the previous element in @set that is lower than current value of @codepoint.
  *
- * Set @codepoint to %HB_SET_VALUE_INVALID to get started.
+ * Set @codepoint to #HB_SET_VALUE_INVALID to get started.
  *
- * Return value: %true if there was a previous value, false otherwise
+ * Return value: %true if there was a previous value, %false otherwise
  *
  * Since: 1.8.0
  **/
@@ -525,9 +528,9 @@ hb_set_previous (const hb_set_t *set,
  * Fetches the next consecutive range of elements in @set that
  * are greater than current value of @last.
  *
- * Set @last to %HB_SET_VALUE_INVALID to get started.
+ * Set @last to #HB_SET_VALUE_INVALID to get started.
  *
- * Return value: %true if there was a next range, false otherwise
+ * Return value: %true if there was a next range, %false otherwise
  *
  * Since: 0.9.7
  **/
@@ -549,9 +552,9 @@ hb_set_next_range (const hb_set_t *set,
  * Fetches the previous consecutive range of elements in @set that
  * are greater than current value of @last.
  *
- * Set @first to %HB_SET_VALUE_INVALID to get started.
+ * Set @first to #HB_SET_VALUE_INVALID to get started.
  *
- * Return value: %true if there was a previous range, false otherwise
+ * Return value: %true if there was a previous range, %false otherwise
  *
  * Since: 1.8.0
  **/
diff --git a/thirdparty/harfbuzz/src/hb-set.h b/thirdparty/harfbuzz/src/hb-set.h
index cafc36dbad..0ad27f4bbd 100644
--- a/thirdparty/harfbuzz/src/hb-set.h
+++ b/thirdparty/harfbuzz/src/hb-set.h
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -36,7 +36,11 @@
 HB_BEGIN_DECLS
 
 
-/*
+/**
+ * HB_SET_VALUE_INVALID:
+ *
+ * Unset #hb_set_t value.
+ *
  * Since: 0.9.21
  */
 #define HB_SET_VALUE_INVALID ((hb_codepoint_t) -1)
diff --git a/thirdparty/harfbuzz/src/hb-set.hh b/thirdparty/harfbuzz/src/hb-set.hh
index b6e2086a2e..ae8b5eb10f 100644
--- a/thirdparty/harfbuzz/src/hb-set.hh
+++ b/thirdparty/harfbuzz/src/hb-set.hh
@@ -244,7 +244,7 @@ struct hb_set_t
 
   bool resize (unsigned int count)
   {
-    if (unlikely (!successful)) return false;
+    if (unlikely (count > pages.length && !successful)) return false;
     if (!pages.resize (count) || !page_map.resize (count))
     {
       pages.resize (page_map.length);
@@ -256,19 +256,14 @@ struct hb_set_t
 
   void reset ()
   {
-    if (unlikely (hb_object_is_immutable (this)))
-      return;
-    clear ();
     successful = true;
+    clear ();
   }
 
   void clear ()
   {
-    if (unlikely (hb_object_is_immutable (this)))
-      return;
-    population = 0;
-    page_map.resize (0);
-    pages.resize (0);
+    if (resize (0))
+      population = 0;
   }
   bool is_empty () const
   {
@@ -278,6 +273,7 @@ struct hb_set_t
 	return false;
     return true;
   }
+  explicit operator bool () const { return !is_empty (); }
 
   void dirty () { population = UINT_MAX; }
 
@@ -389,6 +385,11 @@ struct hb_set_t
   {
     if (ds <= de)
     {
+      // Pre-allocate the workspace that compact() will need so we can bail on allocation failure
+      // before attempting to rewrite the page map.
+      hb_vector_t<unsigned> compact_workspace;
+      if (unlikely (!allocate_compact_workspace (compact_workspace))) return;
+
       unsigned int write_index = 0;
       for (unsigned int i = 0; i < page_map.length; i++)
       {
@@ -396,11 +397,12 @@ struct hb_set_t
 	if (m < ds || de < m)
 	  page_map[write_index++] = page_map[i];
       }
-      compact (write_index);
+      compact (compact_workspace, write_index);
       resize (write_index);
     }
   }
 
+
   public:
   void del_range (hb_codepoint_t a, hb_codepoint_t b)
   {
@@ -512,20 +514,37 @@ struct hb_set_t
     return true;
   }
 
-  void compact (unsigned int length)
+  bool allocate_compact_workspace(hb_vector_t<unsigned>& workspace)
+  {
+    if (unlikely(!workspace.resize (pages.length)))
+    {
+      successful = false;
+      return false;
+    }
+
+    return true;
+  }
+
+
+  /*
+   * workspace should be a pre-sized vector allocated to hold at exactly pages.length
+   * elements.
+   */
+  void compact (hb_vector_t<unsigned>& workspace,
+                unsigned int length)
   {
-    hb_vector_t<uint32_t> old_index_to_page_map_index;
-    old_index_to_page_map_index.resize(pages.length);
-    for (uint32_t i = 0; i < old_index_to_page_map_index.length; i++)
-      old_index_to_page_map_index[i] = 0xFFFFFFFF;
+    assert(workspace.length == pages.length);
+    hb_vector_t<unsigned>& old_index_to_page_map_index = workspace;
 
-    for (uint32_t i = 0; i < length; i++)
+    hb_fill (old_index_to_page_map_index.writer(), 0xFFFFFFFF);
+    /* TODO(iter) Rewrite as dagger? */
+    for (unsigned i = 0; i < length; i++)
       old_index_to_page_map_index[page_map[i].index] =  i;
 
     compact_pages (old_index_to_page_map_index);
   }
 
-  void compact_pages (const hb_vector_t<uint32_t>& old_index_to_page_map_index)
+  void compact_pages (const hb_vector_t<unsigned>& old_index_to_page_map_index)
   {
     unsigned int write_index = 0;
     for (unsigned int i = 0; i < pages.length; i++)
@@ -543,6 +562,9 @@ struct hb_set_t
   template <typename Op>
   void process (const Op& op, const hb_set_t *other)
   {
+    const bool passthru_left = op (1, 0);
+    const bool passthru_right = op (0, 1);
+
     if (unlikely (!successful)) return;
 
     dirty ();
@@ -554,11 +576,17 @@ struct hb_set_t
     unsigned int count = 0, newCount = 0;
     unsigned int a = 0, b = 0;
     unsigned int write_index = 0;
+
+    // Pre-allocate the workspace that compact() will need so we can bail on allocation failure
+    // before attempting to rewrite the page map.
+    hb_vector_t<unsigned> compact_workspace;
+    if (!passthru_left && unlikely (!allocate_compact_workspace (compact_workspace))) return;
+
     for (; a < na && b < nb; )
     {
       if (page_map[a].major == other->page_map[b].major)
       {
-	if (!Op::passthru_left)
+	if (!passthru_left)
 	{
 	  // Move page_map entries that we're keeping from the left side set
 	  // to the front of the page_map vector. This isn't necessary if
@@ -575,27 +603,27 @@ struct hb_set_t
       }
       else if (page_map[a].major < other->page_map[b].major)
       {
-	if (Op::passthru_left)
+	if (passthru_left)
 	  count++;
 	a++;
       }
       else
       {
-	if (Op::passthru_right)
+	if (passthru_right)
 	  count++;
 	b++;
       }
     }
-    if (Op::passthru_left)
+    if (passthru_left)
       count += na - a;
-    if (Op::passthru_right)
+    if (passthru_right)
       count += nb - b;
 
-    if (!Op::passthru_left)
+    if (!passthru_left)
     {
       na  = write_index;
       next_page = write_index;
-      compact (write_index);
+      compact (compact_workspace, write_index);
     }
 
     if (!resize (count))
@@ -619,7 +647,7 @@ struct hb_set_t
       else if (page_map[a - 1].major > other->page_map[b - 1].major)
       {
 	a--;
-	if (Op::passthru_left)
+	if (passthru_left)
 	{
 	  count--;
 	  page_map[count] = page_map[a];
@@ -628,7 +656,7 @@ struct hb_set_t
       else
       {
 	b--;
-	if (Op::passthru_right)
+	if (passthru_right)
 	{
 	  count--;
 	  page_map[count].major = other->page_map[b].major;
@@ -637,14 +665,14 @@ struct hb_set_t
 	}
       }
     }
-    if (Op::passthru_left)
+    if (passthru_left)
       while (a)
       {
 	a--;
 	count--;
 	page_map[count] = page_map [a];
       }
-    if (Op::passthru_right)
+    if (passthru_right)
       while (b)
       {
 	b--;
@@ -655,6 +683,9 @@ struct hb_set_t
       }
     assert (!count);
     if (pages.length > newCount)
+      // This resize() doesn't need to be checked because we can't get here
+      // if the set is currently in_error() and this only resizes downwards
+      // which will always succeed if the set is not in_error().
       resize (newCount);
   }
 
diff --git a/thirdparty/harfbuzz/src/hb-shape-plan.cc b/thirdparty/harfbuzz/src/hb-shape-plan.cc
index 65a5fc4512..0d9eaddaa6 100644
--- a/thirdparty/harfbuzz/src/hb-shape-plan.cc
+++ b/thirdparty/harfbuzz/src/hb-shape-plan.cc
@@ -329,12 +329,12 @@ hb_shape_plan_destroy (hb_shape_plan_t *shape_plan)
  * @shape_plan: A shaping plan
  * @key: The user-data key to set
  * @data: A pointer to the user data
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the given shaping plan. 
  *
- * Return value:
+ * Return value: %true if success, %false otherwise.
  *
  * Since: 0.9.7
  **/
@@ -439,7 +439,7 @@ _hb_shape_plan_execute_internal (hb_shape_plan_t    *shape_plan,
  * Executes the given shaping plan on the specified buffer, using
  * the given @font and @features.
  *
- * Return value: 
+ * Return value: %true if success, %false otherwise.
  *
  * Since: 0.9.7
  **/
diff --git a/thirdparty/harfbuzz/src/hb-shape-plan.h b/thirdparty/harfbuzz/src/hb-shape-plan.h
index 336524ee2f..fc7c041899 100644
--- a/thirdparty/harfbuzz/src/hb-shape-plan.h
+++ b/thirdparty/harfbuzz/src/hb-shape-plan.h
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
diff --git a/thirdparty/harfbuzz/src/hb-shape.cc b/thirdparty/harfbuzz/src/hb-shape.cc
index a3debce397..c442f4403b 100644
--- a/thirdparty/harfbuzz/src/hb-shape.cc
+++ b/thirdparty/harfbuzz/src/hb-shape.cc
@@ -111,10 +111,10 @@ hb_shape_list_shapers ()
  * hb_shape_full:
  * @font: an #hb_font_t to use for shaping
  * @buffer: an #hb_buffer_t to shape
- * @features: (array length=num_features) (allow-none): an array of user
+ * @features: (array length=num_features) (nullable): an array of user
  *    specified #hb_feature_t or %NULL
  * @num_features: the length of @features array
- * @shaper_list: (array zero-terminated=1) (allow-none): a %NULL-terminated
+ * @shaper_list: (array zero-terminated=1) (nullable): a %NULL-terminated
  *    array of shapers to use or %NULL
  *
  * See hb_shape() for details. If @shaper_list is not %NULL, the specified
@@ -146,7 +146,7 @@ hb_shape_full (hb_font_t          *font,
  * hb_shape:
  * @font: an #hb_font_t to use for shaping
  * @buffer: an #hb_buffer_t to shape
- * @features: (array length=num_features) (allow-none): an array of user
+ * @features: (array length=num_features) (nullable): an array of user
  *    specified #hb_feature_t or %NULL
  * @num_features: the length of @features array
  *
diff --git a/thirdparty/harfbuzz/src/hb-shape.h b/thirdparty/harfbuzz/src/hb-shape.h
index 39507ff744..922f8c011e 100644
--- a/thirdparty/harfbuzz/src/hb-shape.h
+++ b/thirdparty/harfbuzz/src/hb-shape.h
@@ -26,7 +26,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
diff --git a/thirdparty/harfbuzz/src/hb-style.cc b/thirdparty/harfbuzz/src/hb-style.cc
index 86b9f7da5f..2f45d119f9 100644
--- a/thirdparty/harfbuzz/src/hb-style.cc
+++ b/thirdparty/harfbuzz/src/hb-style.cc
@@ -65,6 +65,7 @@ typedef enum {
   HB_STYLE_TAG_WIDTH		= HB_TAG ('w','d','t','h'),
   HB_STYLE_TAG_WEIGHT		= HB_TAG ('w','g','h','t'),
 
+  /*< private >*/
   _HB_STYLE_TAG_MAX_VALUE	= HB_TAG_MAX_SIGNED /*< skip >*/
 } hb_style_tag_t;
 
diff --git a/thirdparty/harfbuzz/src/hb-style.h b/thirdparty/harfbuzz/src/hb-style.h
index 1209c79e94..f5776cee58 100644
--- a/thirdparty/harfbuzz/src/hb-style.h
+++ b/thirdparty/harfbuzz/src/hb-style.h
@@ -22,7 +22,7 @@
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
diff --git a/thirdparty/harfbuzz/src/hb-subset-plan.cc b/thirdparty/harfbuzz/src/hb-subset-plan.cc
index 24beada3e8..d055783a4d 100644
--- a/thirdparty/harfbuzz/src/hb-subset-plan.cc
+++ b/thirdparty/harfbuzz/src/hb-subset-plan.cc
@@ -88,10 +88,17 @@ _gsub_closure_glyphs_lookups_features (hb_face_t *face,
 			 &lookup_indices);
   _remap_indexes (&lookup_indices, gsub_lookups);
 
-  //closure features
+  // Collect and prune features
   hb_set_t feature_indices;
-  gsub->closure_features (gsub_lookups, &feature_indices);
+  hb_ot_layout_collect_features (face,
+                                 HB_OT_TAG_GSUB,
+                                 nullptr,
+                                 nullptr,
+                                 nullptr,
+                                 &feature_indices);
+  gsub->prune_features (gsub_lookups, &feature_indices);
   _remap_indexes (&feature_indices, gsub_features);
+
   gsub.destroy ();
 }
 
@@ -114,9 +121,15 @@ _gpos_closure_lookups_features (hb_face_t      *face,
 			 &lookup_indices);
   _remap_indexes (&lookup_indices, gpos_lookups);
 
-  //closure features
+  // Collect and prune features
   hb_set_t feature_indices;
-  gpos->closure_features (gpos_lookups, &feature_indices);
+  hb_ot_layout_collect_features (face,
+                                 HB_OT_TAG_GPOS,
+                                 nullptr,
+                                 nullptr,
+                                 nullptr,
+                                 &feature_indices);
+  gpos->prune_features (gpos_lookups, &feature_indices);
   _remap_indexes (&feature_indices, gpos_features);
   gpos.destroy ();
 }
@@ -243,7 +256,11 @@ _populate_gids_to_retain (hb_subset_plan_t* plan,
 
 #ifndef HB_NO_VAR
   if (close_over_gdef)
-    _collect_layout_variation_indices (plan->source, plan->_glyphset, plan->gpos_lookups, plan->layout_variation_indices, plan->layout_variation_idx_map);
+    _collect_layout_variation_indices (plan->source,
+                                       plan->_glyphset_gsub,
+                                       plan->gpos_lookups,
+                                       plan->layout_variation_indices,
+                                       plan->layout_variation_idx_map);
 #endif
 
 #ifndef HB_NO_SUBSET_CFF
diff --git a/thirdparty/harfbuzz/src/hb-subset-plan.hh b/thirdparty/harfbuzz/src/hb-subset-plan.hh
index e9f603dd1d..cc9cb7a1a2 100644
--- a/thirdparty/harfbuzz/src/hb-subset-plan.hh
+++ b/thirdparty/harfbuzz/src/hb-subset-plan.hh
@@ -172,12 +172,15 @@ struct hb_subset_plan_t
   add_table (hb_tag_t tag,
 	     hb_blob_t *contents)
   {
-    hb_blob_t *source_blob = source->reference_table (tag);
-    DEBUG_MSG(SUBSET, nullptr, "add table %c%c%c%c, dest %d bytes, source %d bytes",
-	      HB_UNTAG(tag),
-	      hb_blob_get_length (contents),
-	      hb_blob_get_length (source_blob));
-    hb_blob_destroy (source_blob);
+    if (HB_DEBUG_SUBSET)
+    {
+      hb_blob_t *source_blob = source->reference_table (tag);
+      DEBUG_MSG(SUBSET, nullptr, "add table %c%c%c%c, dest %d bytes, source %d bytes",
+		HB_UNTAG(tag),
+		hb_blob_get_length (contents),
+		hb_blob_get_length (source_blob));
+      hb_blob_destroy (source_blob);
+    }
     return hb_face_builder_add_table (dest, tag, contents);
   }
 };
diff --git a/thirdparty/harfbuzz/src/hb-unicode.cc b/thirdparty/harfbuzz/src/hb-unicode.cc
index d7f6a6e130..7470bb1b6e 100644
--- a/thirdparty/harfbuzz/src/hb-unicode.cc
+++ b/thirdparty/harfbuzz/src/hb-unicode.cc
@@ -276,7 +276,7 @@ hb_unicode_funcs_destroy (hb_unicode_funcs_t *ufuncs)
  * @ufuncs: The Unicode-functions structure
  * @key: The user-data key
  * @data: A pointer to the user data
- * @destroy: (optional): A callback to call when @data is not needed anymore
+ * @destroy: (nullable): A callback to call when @data is not needed anymore
  * @replace: Whether to replace an existing data with the same key
  *
  * Attaches a user-data key/data pair to the specified Unicode-functions structure. 
@@ -340,7 +340,7 @@ hb_unicode_funcs_make_immutable (hb_unicode_funcs_t *ufuncs)
  * Tests whether the specified Unicode-functions structure
  * is immutable.
  *
- * Return value: %true if @ufuncs is immutable, false otherwise
+ * Return value: %true if @ufuncs is immutable, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -421,7 +421,7 @@ HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
  * Calls the composition function of the specified
  * Unicode-functions structure @ufuncs.
  *
- * Return value: %true if @a and @b composed, false otherwise
+ * Return value: %true if @a and @b composed, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -446,7 +446,7 @@ hb_unicode_compose (hb_unicode_funcs_t *ufuncs,
  * Calls the decomposition function of the specified
  * Unicode-functions structure @ufuncs.
  *
- * Return value: %true if @ab was decomposed, false otherwise
+ * Return value: %true if @ab was decomposed, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -469,7 +469,7 @@ hb_unicode_decompose (hb_unicode_funcs_t *ufuncs,
  * Fetches the compatibility decomposition of a Unicode
  * code point. Deprecated.
  *
- * Return value:
+ * Return value: length of @decomposed.
  *
  * Since: 0.9.2
  * Deprecated: 2.0.0
diff --git a/thirdparty/harfbuzz/src/hb-unicode.h b/thirdparty/harfbuzz/src/hb-unicode.h
index 7ea0848c0f..c04ee15a09 100644
--- a/thirdparty/harfbuzz/src/hb-unicode.h
+++ b/thirdparty/harfbuzz/src/hb-unicode.h
@@ -28,7 +28,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -41,7 +41,9 @@ HB_BEGIN_DECLS
 
 
 /**
- * HB_UNICODE_MAX
+ * HB_UNICODE_MAX:
+ *
+ * Maximum valid Unicode code point.
  *
  * Since: 1.9.0
  **/
@@ -427,7 +429,7 @@ typedef hb_script_t			(*hb_unicode_script_func_t)		(hb_unicode_funcs_t *ufuncs,
  * The method must return an #hb_bool_t indicating the success
  * of the composition.
  * 
- * Return value: True is @a,@b composed, false otherwise
+ * Return value: %true is @a,@b composed, %false otherwise
  *
  **/
 typedef hb_bool_t			(*hb_unicode_compose_func_t)		(hb_unicode_funcs_t *ufuncs,
@@ -451,7 +453,7 @@ typedef hb_bool_t			(*hb_unicode_compose_func_t)		(hb_unicode_funcs_t *ufuncs,
  * output parameters (if successful). The method must return an
  * #hb_bool_t indicating the success of the composition.
  * 
- * Return value: True if @ab decomposed, false otherwise
+ * Return value: %true if @ab decomposed, %false otherwise
  *
  **/
 typedef hb_bool_t			(*hb_unicode_decompose_func_t)		(hb_unicode_funcs_t *ufuncs,
@@ -467,7 +469,7 @@ typedef hb_bool_t			(*hb_unicode_decompose_func_t)		(hb_unicode_funcs_t *ufuncs,
  * @ufuncs: A Unicode-functions structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_unicode_combining_class_func_t.
  *
@@ -483,7 +485,7 @@ hb_unicode_funcs_set_combining_class_func (hb_unicode_funcs_t *ufuncs,
  * @ufuncs: A Unicode-functions structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_unicode_general_category_func_t.
  *
@@ -499,7 +501,7 @@ hb_unicode_funcs_set_general_category_func (hb_unicode_funcs_t *ufuncs,
  * @ufuncs: A Unicode-functions structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_unicode_mirroring_func_t.
  *
@@ -515,7 +517,7 @@ hb_unicode_funcs_set_mirroring_func (hb_unicode_funcs_t *ufuncs,
  * @ufuncs: A Unicode-functions structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_unicode_script_func_t.
  *
@@ -531,7 +533,7 @@ hb_unicode_funcs_set_script_func (hb_unicode_funcs_t *ufuncs,
  * @ufuncs: A Unicode-functions structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_unicode_compose_func_t.
  *
@@ -547,7 +549,7 @@ hb_unicode_funcs_set_compose_func (hb_unicode_funcs_t *ufuncs,
  * @ufuncs: A Unicode-functions structure
  * @func: (closure user_data) (destroy destroy) (scope notified): The callback function to assign
  * @user_data: Data to pass to @func
- * @destroy: (optional): The function to call when @user_data is not needed anymore
+ * @destroy: (nullable): The function to call when @user_data is not needed anymore
  *
  * Sets the implementation function for #hb_unicode_decompose_func_t.
  *
@@ -624,40 +626,12 @@ HB_EXTERN hb_script_t
 hb_unicode_script (hb_unicode_funcs_t *ufuncs,
 		   hb_codepoint_t unicode);
 
-/**
- * hb_unicode_compose:
- * @ufuncs: The Unicode-functions structure
- * @a: The first code point to compose
- * @b: The second code point to compose
- * @ab: (out): The composed code point
- *
- * Composes the code point sequence @a,@b by canonical equivalence into
- * code point @ab.
- *
- * Return value: True is @a,@b composed, false otherwise
- *
- * Since: 0.9.2
- **/
 HB_EXTERN hb_bool_t
 hb_unicode_compose (hb_unicode_funcs_t *ufuncs,
 		    hb_codepoint_t      a,
 		    hb_codepoint_t      b,
 		    hb_codepoint_t     *ab);
 
-/**
- * hb_unicode_decompose:
- * @ufuncs: The Unicode-functions structure
- * @ab: The code point to decompose
- * @a: (out): The first decomposed code point
- * @b: (out): The second decomposed code point
- *
- * Decomposes code point @ab by canonical equivalence, into code points
- * @a and @b.
- *
- * Return value: True if @ab decomposed, false otherwise
- *
- * Since: 0.9.2
- **/
 HB_EXTERN hb_bool_t
 hb_unicode_decompose (hb_unicode_funcs_t *ufuncs,
 		      hb_codepoint_t      ab,
diff --git a/thirdparty/harfbuzz/src/hb-vector.hh b/thirdparty/harfbuzz/src/hb-vector.hh
index 079b94a6b4..13517a9c29 100644
--- a/thirdparty/harfbuzz/src/hb-vector.hh
+++ b/thirdparty/harfbuzz/src/hb-vector.hh
@@ -80,7 +80,12 @@ struct hb_vector_t
     fini ();
   }
 
-  void reset () { resize (0); }
+  void reset ()
+  {
+    if (unlikely (in_error ()))
+      allocated = length; // Big hack!
+    resize (0);
+  }
 
   hb_vector_t& operator = (const hb_vector_t &o)
   {
@@ -181,7 +186,7 @@ struct hb_vector_t
   /* Allocate for size but don't adjust length. */
   bool alloc (unsigned int size)
   {
-    if (unlikely (allocated < 0))
+    if (unlikely (in_error ()))
       return false;
 
     if (likely (size <= (unsigned) allocated))
@@ -195,7 +200,7 @@ struct hb_vector_t
 
     Type *new_array = nullptr;
     bool overflows =
-      (int) new_allocated < 0 ||
+      (int) in_error () ||
       (new_allocated < (unsigned) allocated) ||
       hb_unsigned_mul_overflows (new_allocated, sizeof (Type));
     if (likely (!overflows))
diff --git a/thirdparty/harfbuzz/src/hb-version.h b/thirdparty/harfbuzz/src/hb-version.h
index da377b9df6..6db58c3f7c 100644
--- a/thirdparty/harfbuzz/src/hb-version.h
+++ b/thirdparty/harfbuzz/src/hb-version.h
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#ifndef HB_H_IN
+#if !defined(HB_H_IN) && !defined(HB_NO_SINGLE_HEADER_ERROR)
 #error "Include <hb.h> instead."
 #endif
 
@@ -36,12 +36,41 @@
 HB_BEGIN_DECLS
 
 
+/**
+ * HB_VERSION_MAJOR:
+ *
+ * The major component of the library version available at compile-time.
+ */
 #define HB_VERSION_MAJOR 2
-#define HB_VERSION_MINOR 7
-#define HB_VERSION_MICRO 4
+/**
+ * HB_VERSION_MINOR:
+ *
+ * The minor component of the library version available at compile-time.
+ */
+#define HB_VERSION_MINOR 8
+/**
+ * HB_VERSION_MICRO:
+ *
+ * The micro component of the library version available at compile-time.
+ */
+#define HB_VERSION_MICRO 0
 
-#define HB_VERSION_STRING "2.7.4"
+/**
+ * HB_VERSION_STRING:
+ *
+ * A string literal containing the library version available at compile-time.
+ */
+#define HB_VERSION_STRING "2.8.0"
 
+/**
+ * HB_VERSION_ATLEAST:
+ * @major: the major component of the version number
+ * @minor: the minor component of the version number
+ * @micro: the micro component of the version number
+ *
+ * Tests the library version at compile-time against a minimum value,
+ * as three integer components.
+ */
 #define HB_VERSION_ATLEAST(major,minor,micro) \
 	((major)*10000+(minor)*100+(micro) <= \
 	 HB_VERSION_MAJOR*10000+HB_VERSION_MINOR*100+HB_VERSION_MICRO)
diff --git a/thirdparty/harfbuzz/src/hb.hh b/thirdparty/harfbuzz/src/hb.hh
index 274a0e98db..18516581c7 100644
--- a/thirdparty/harfbuzz/src/hb.hh
+++ b/thirdparty/harfbuzz/src/hb.hh
@@ -62,7 +62,6 @@
 
 /* Error.  Should never happen. */
 #ifndef HB_NO_PRAGMA_GCC_DIAGNOSTIC_ERROR
-#pragma GCC diagnostic error   "-Wc++11-narrowing"
 #pragma GCC diagnostic error   "-Wcast-align"
 #pragma GCC diagnostic error   "-Wcast-function-type"
 #pragma GCC diagnostic error   "-Wdelete-non-virtual-dtor"
@@ -75,6 +74,7 @@
 #pragma GCC diagnostic error   "-Wmissing-braces"
 #pragma GCC diagnostic error   "-Wmissing-declarations"
 #pragma GCC diagnostic error   "-Wmissing-prototypes"
+#pragma GCC diagnostic error   "-Wnarrowing"
 #pragma GCC diagnostic error   "-Wnested-externs"
 #pragma GCC diagnostic error   "-Wold-style-definition"
 #pragma GCC diagnostic error   "-Wpointer-arith"
@@ -126,6 +126,7 @@
 #pragma GCC diagnostic ignored "-Wformat-zero-length"
 #pragma GCC diagnostic ignored "-Wmissing-field-initializers"
 #pragma GCC diagnostic ignored "-Wpacked" // Erratic impl in clang
+#pragma GCC diagnostic ignored "-Wrange-loop-analysis" // https://github.com/harfbuzz/harfbuzz/issues/2834
 #pragma GCC diagnostic ignored "-Wstrict-aliasing"
 #pragma GCC diagnostic ignored "-Wtype-limits"
 #pragma GCC diagnostic ignored "-Wc++11-compat" // only gcc raises it
@@ -175,15 +176,15 @@
 #include "hb-aat.h"
 #define HB_AAT_H_IN
 
-#include <limits.h>
-#include <math.h>
-#include <float.h>
-#include <stdlib.h>
-#include <stddef.h>
-#include <string.h>
-#include <assert.h>
-#include <stdio.h>
-#include <stdarg.h>
+#include <cassert>
+#include <cfloat>
+#include <climits>
+#include <cmath>
+#include <cstdarg>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
 
 #if (defined(_MSC_VER) && _MSC_VER >= 1500) || defined(__MINGW32__)
 #ifdef __MINGW32_VERSION
@@ -244,12 +245,8 @@ extern "C" void  hb_free_impl(void *ptr);
 #endif
 
 #if defined(__GNUC__) && (__GNUC__ >= 3)
-#define HB_PURE_FUNC	__attribute__((pure))
-#define HB_CONST_FUNC	__attribute__((const))
 #define HB_PRINTF_FUNC(format_idx, arg_idx) __attribute__((__format__ (__printf__, format_idx, arg_idx)))
 #else
-#define HB_PURE_FUNC
-#define HB_CONST_FUNC
 #define HB_PRINTF_FUNC(format_idx, arg_idx)
 #endif
 #if defined(__GNUC__) && (__GNUC__ >= 4) || (__clang__)
@@ -394,7 +391,7 @@ extern "C" void  hb_free_impl(void *ptr);
 #endif
 
 #ifndef HB_NO_ERRNO
-#  include <errno.h>
+#  include <cerrno>
 #else
 static int HB_UNUSED _hb_errno = 0;
 #  undef errno
@@ -440,181 +437,12 @@ static int HB_UNUSED _hb_errno = 0;
 #define HB_STMT_START do
 #define HB_STMT_END   while (0)
 
-/* Static-assert as expression. */
-template <unsigned int cond> class hb_assert_constant_t;
-template <> class hb_assert_constant_t<1> {};
-#define ASSERT_STATIC_EXPR_ZERO(_cond) (0 * (unsigned int) sizeof (hb_assert_constant_t<_cond>))
-
 /* Lets assert int types.  Saves trouble down the road. */
-static_assert ((sizeof (int8_t) == 1), "");
-static_assert ((sizeof (uint8_t) == 1), "");
-static_assert ((sizeof (int16_t) == 2), "");
-static_assert ((sizeof (uint16_t) == 2), "");
-static_assert ((sizeof (int32_t) == 4), "");
-static_assert ((sizeof (uint32_t) == 4), "");
-static_assert ((sizeof (int64_t) == 8), "");
-static_assert ((sizeof (uint64_t) == 8), "");
 static_assert ((sizeof (hb_codepoint_t) == 4), "");
 static_assert ((sizeof (hb_position_t) == 4), "");
 static_assert ((sizeof (hb_mask_t) == 4), "");
 static_assert ((sizeof (hb_var_int_t) == 4), "");
 
-#define HB_DELETE_COPY_ASSIGN(TypeName) \
-  TypeName(const TypeName&) = delete; \
-  void operator=(const TypeName&) = delete
-#define HB_DELETE_CREATE_COPY_ASSIGN(TypeName) \
-  TypeName() = delete; \
-  TypeName(const TypeName&) = delete; \
-  void operator=(const TypeName&) = delete
-
-
-/* Flags */
-
-/* Enable bitwise ops on enums marked as flags_t */
-/* To my surprise, looks like the function resolver is happy to silently cast
- * one enum to another...  So this doesn't provide the type-checking that I
- * originally had in mind... :(.
- *
- * For MSVC warnings, see: https://github.com/harfbuzz/harfbuzz/pull/163
- */
-#ifdef _MSC_VER
-# pragma warning(disable:4200)
-# pragma warning(disable:4800)
-#endif
-#define HB_MARK_AS_FLAG_T(T) \
-	extern "C++" { \
-	  static inline T operator | (T l, T r) { return T ((unsigned) l | (unsigned) r); } \
-	  static inline T operator & (T l, T r) { return T ((unsigned) l & (unsigned) r); } \
-	  static inline T operator ^ (T l, T r) { return T ((unsigned) l ^ (unsigned) r); } \
-	  static inline T operator ~ (T r) { return T (~(unsigned int) r); } \
-	  static inline T& operator |= (T &l, T r) { l = l | r; return l; } \
-	  static inline T& operator &= (T& l, T r) { l = l & r; return l; } \
-	  static inline T& operator ^= (T& l, T r) { l = l ^ r; return l; } \
-	} \
-	static_assert (true, "")
-
-/* Useful for set-operations on small enums.
- * For example, for testing "x ∈ {x1, x2, x3}" use:
- * (FLAG_UNSAFE(x) & (FLAG(x1) | FLAG(x2) | FLAG(x3)))
- */
-#define FLAG(x) (ASSERT_STATIC_EXPR_ZERO ((unsigned)(x) < 32) + (((uint32_t) 1U) << (unsigned)(x)))
-#define FLAG_UNSAFE(x) ((unsigned)(x) < 32 ? (((uint32_t) 1U) << (unsigned)(x)) : 0)
-#define FLAG_RANGE(x,y) (ASSERT_STATIC_EXPR_ZERO ((x) < (y)) + FLAG(y+1) - FLAG(x))
-#define FLAG64(x) (ASSERT_STATIC_EXPR_ZERO ((unsigned)(x) < 64) + (((uint64_t) 1ULL) << (unsigned)(x)))
-#define FLAG64_UNSAFE(x) ((unsigned)(x) < 64 ? (((uint64_t) 1ULL) << (unsigned)(x)) : 0)
-
-
-/* Size signifying variable-sized array */
-#ifndef HB_VAR_ARRAY
-#define HB_VAR_ARRAY 1
-#endif
-
-static inline float
-_hb_roundf (float x) { return floorf (x + .5f); }
-#define roundf(x) _hb_roundf(x)
-
-/* Endian swap, used in Windows related backends */
-static inline uint16_t hb_uint16_swap (const uint16_t v)
-{ return (v >> 8) | (v << 8); }
-static inline uint32_t hb_uint32_swap (const uint32_t v)
-{ return (hb_uint16_swap (v) << 16) | hb_uint16_swap (v >> 16); }
-
-/*
- * Big-endian integers.  Here because fundamental.
- */
-
-template <typename Type, int Bytes> struct BEInt;
-
-template <typename Type>
-struct BEInt<Type, 1>
-{
-  public:
-  BEInt<Type, 1>& operator = (Type V)
-  {
-    v = V;
-    return *this;
-  }
-  operator Type () const { return v; }
-  private: uint8_t v;
-};
-template <typename Type>
-struct BEInt<Type, 2>
-{
-  public:
-  BEInt<Type, 2>& operator = (Type V)
-  {
-    v[0] = (V >>  8) & 0xFF;
-    v[1] = (V      ) & 0xFF;
-    return *this;
-  }
-  operator Type () const
-  {
-#if ((defined(__GNUC__) && __GNUC__ >= 5) || defined(__clang__)) && \
-    defined(__BYTE_ORDER) && \
-    (__BYTE_ORDER == __LITTLE_ENDIAN || __BYTE_ORDER == __BIG_ENDIAN)
-    /* Spoon-feed the compiler a big-endian integer with alignment 1.
-     * https://github.com/harfbuzz/harfbuzz/pull/1398 */
-    struct __attribute__((packed)) packed_uint16_t { uint16_t v; };
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-    return __builtin_bswap16 (((packed_uint16_t *) this)->v);
-#else /* __BYTE_ORDER == __BIG_ENDIAN */
-    return ((packed_uint16_t *) this)->v;
-#endif
-#endif
-    return (v[0] <<  8)
-	 + (v[1]      );
-  }
-  private: uint8_t v[2];
-};
-template <typename Type>
-struct BEInt<Type, 3>
-{
-  public:
-  BEInt<Type, 3>& operator = (Type V)
-  {
-    v[0] = (V >> 16) & 0xFF;
-    v[1] = (V >>  8) & 0xFF;
-    v[2] = (V      ) & 0xFF;
-    return *this;
-  }
-  operator Type () const
-  {
-    return (v[0] << 16)
-	 + (v[1] <<  8)
-	 + (v[2]      );
-  }
-  private: uint8_t v[3];
-};
-template <typename Type>
-struct BEInt<Type, 4>
-{
-  public:
-  BEInt<Type, 4>& operator = (Type V)
-  {
-    v[0] = (V >> 24) & 0xFF;
-    v[1] = (V >> 16) & 0xFF;
-    v[2] = (V >>  8) & 0xFF;
-    v[3] = (V      ) & 0xFF;
-    return *this;
-  }
-  operator Type () const
-  {
-    return (v[0] << 24)
-	 + (v[1] << 16)
-	 + (v[2] <<  8)
-	 + (v[3]      );
-  }
-  private: uint8_t v[4];
-};
-
-
-/*
- * For lack of a better place, put Zawgyi script hack here.
- * https://github.com/harfbuzz/harfbuzz/issues/1162
- */
-
-#define HB_SCRIPT_MYANMAR_ZAWGYI	((hb_script_t) HB_TAG ('Q','a','a','g'))
-
 
 /* Headers we include for everyone.  Keep topologically sorted by dependency.
  * They express dependency amongst themselves, but no other file should include