1 files changed, 19 insertions, 0 deletions
diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-fallback.cc b/thirdparty/harfbuzz/src/hb-ot-shape-fallback.cc
index eb1bc79768..671f30327f 100644
--- a/thirdparty/harfbuzz/src/hb-ot-shape-fallback.cc
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-fallback.cc
@@ -446,6 +446,9 @@ _hb_ot_shape_fallback_mark_position (const hb_ot_shape_plan_t *plan,
   return;
 #endif
 
+  if (!buffer->message (font, "start fallback mark"))
+    return;
+
   _hb_buffer_assert_gsubgpos_vars (buffer);
 
   unsigned int start = 0;
@@ -457,6 +460,8 @@ _hb_ot_shape_fallback_mark_position (const hb_ot_shape_plan_t *plan,
       start = i;
     }
   position_cluster (plan, font, buffer, start, count, adjust_offsets_when_zeroing);
+
+  (void) buffer->message (font, "end fallback mark");
 }
 
 
@@ -492,6 +497,9 @@ _hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan,
 #endif
 
 #ifndef HB_DISABLE_DEPRECATED
+  if (!buffer->message (font, "start fallback kern"))
+    return;
+
   if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction) ?
       !font->has_glyph_h_kerning_func () :
       !font->has_glyph_v_kerning_func ())
@@ -508,6 +516,8 @@ _hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan,
 
   if (reverse)
     buffer->reverse ();
+
+  (void) buffer->message (font, "end fallback kern");
 #endif
 }
 
@@ -525,6 +535,15 @@ _hb_ot_shape_fallback_spaces (const hb_ot_shape_plan_t *plan HB_UNUSED,
   for (unsigned int i = 0; i < count; i++)
     if (_hb_glyph_info_is_unicode_space (&info[i]) && !_hb_glyph_info_ligated (&info[i]))
     {
+      /* If font had no ASCII space and we used the invisible glyph, give it a 1/4 EM default advance. */
+      if (buffer->invisible && info[i].codepoint == buffer->invisible)
+      {
+        if (horizontal)
+	  pos[i].x_advance = +font->x_scale / 4;
+        else
+	  pos[i].y_advance = -font->y_scale / 4;
+      }
+
       hb_unicode_funcs_t::space_t space_type = _hb_glyph_info_get_unicode_space_fallback_type (&info[i]);
       hb_codepoint_t glyph;
       typedef hb_unicode_funcs_t t;