libpng: Update to upstream version 1.6.32

Fixes security vulnerability in our 1.6.31rc01 snapshot.

17 files changed, 235 insertions, 89 deletions

diff --git a/thirdparty/libpng/arm/filter_neon.S b/thirdparty/libpng/arm/filter_neon.S
index 09267c6030..000764cd21 100644
--- a/thirdparty/libpng/arm/filter_neon.S
+++ b/thirdparty/libpng/arm/filter_neon.S
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2014,2017 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.31 [July 27, 2017]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
diff --git a/thirdparty/libpng/png.c b/thirdparty/libpng/png.c
index 87fda0b306..2352df13cb 100644
--- a/thirdparty/libpng/png.c
+++ b/thirdparty/libpng/png.c
@@ -1,7 +1,7 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.32 [August 24, 2017]
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -14,7 +14,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_31rc01 Your_png_h_is_not_version_1_6_31rc01;
+typedef png_libpng_version_1_6_32 Your_png_h_is_not_version_1_6_32;
 
 #ifdef __GNUC__
 /* The version tests may need to be added to, but the problem warning has
@@ -619,8 +619,18 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
    /* Free any eXIf entry */
    if (((mask & PNG_FREE_EXIF) & info_ptr->free_me) != 0)
    {
-      png_free(png_ptr, info_ptr->exif);
-      info_ptr->exif = NULL;
+# ifdef PNG_READ_eXIf_SUPPORTED
+      if (info_ptr->eXIf_buf)
+      {
+         png_free(png_ptr, info_ptr->eXIf_buf);
+         info_ptr->eXIf_buf = NULL;
+      }
+# endif
+      if (info_ptr->exif)
+      {
+         png_free(png_ptr, info_ptr->exif);
+         info_ptr->exif = NULL;
+      }
       info_ptr->valid &= ~PNG_INFO_eXIf;
    }
 #endif
@@ -806,14 +816,14 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.31rc01 - July 19, 2017" PNG_STRING_NEWLINE \
+      "libpng version 1.6.32 - August 24, 2017" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
       "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
       "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
       PNG_STRING_NEWLINE;
 #  else
-   return "libpng version 1.6.31rc01 - July 19, 2017\
+   return "libpng version 1.6.32 - August 24, 2017\
       Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
diff --git a/thirdparty/libpng/png.h b/thirdparty/libpng/png.h
index 80ecc82c3a..51ac8abe74 100644
--- a/thirdparty/libpng/png.h
+++ b/thirdparty/libpng/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.31rc01, July 19, 2017
+ * libpng version 1.6.32, August 24, 2017
  *
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -12,7 +12,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.31rc01, July 19, 2017:
+ *   libpng versions 0.97, January 1998, through 1.6.32, August 24, 2017:
  *     Glenn Randers-Pehrson.
  *   See also "Contributing Authors", below.
  */
@@ -25,7 +25,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.0.7, July 1, 2000 through 1.6.31rc01, July 19, 2017 are
+ * libpng versions 1.0.7, July 1, 2000 through 1.6.32, August 24, 2017 are
  * Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
  * derived from libpng-1.0.6, and are distributed according to the same
  * disclaimer and license as libpng-1.0.6 with the following individuals
@@ -213,7 +213,7 @@
  *    ...
  *    1.5.28                  15    10527  15.so.15.28[.0]
  *    ...
- *    1.6.31                  16    10631  16.so.16.31[.0]
+ *    1.6.32                  16    10632  16.so.16.32[.0]
  *
  *    Henceforth the source version will match the shared-library major
  *    and minor numbers; the shared-library major version number will be
@@ -241,13 +241,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    July 19, 2017
+ *    August 24, 2017
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.31rc01 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.32 are Y2K compliant.  It is my belief that
  *    earlier versions were also Y2K compliant.
  *
  *    Libpng only has two year fields.  One is a 2-byte unsigned integer
@@ -309,8 +309,8 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.31rc01"
-#define PNG_HEADER_VERSION_STRING " libpng version 1.6.31rc01 - July 19, 2017\n"
+#define PNG_LIBPNG_VER_STRING "1.6.32"
+#define PNG_HEADER_VERSION_STRING " libpng version 1.6.32 - August 24, 2017\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -318,13 +318,13 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 31
+#define PNG_LIBPNG_VER_RELEASE 32
 
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
-#define PNG_LIBPNG_VER_BUILD  01
+#define PNG_LIBPNG_VER_BUILD  0
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -341,7 +341,7 @@
 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
                                        PNG_LIBPNG_BUILD_PRIVATE */
 
-#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_RC
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
 
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
@@ -349,7 +349,7 @@
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10631 /* 1.6.31 */
+#define PNG_LIBPNG_VER 10632 /* 1.6.32 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -459,7 +459,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_6_31rc01;
+typedef char* png_libpng_version_1_6_32;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -2014,6 +2014,11 @@ PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
     png_inforp info_ptr, png_bytep *exif));
 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
     png_inforp info_ptr, const png_bytep exif));
+
+PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
+    png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
+PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
+    png_inforp info_ptr, const png_uint_32 num_exif, const png_bytep exif));
 #endif
 
 #ifdef PNG_gAMA_SUPPORTED
@@ -3259,7 +3264,7 @@ PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
  * one to use is one more than this.)
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
-  PNG_EXPORT_LAST_ORDINAL(247);
+  PNG_EXPORT_LAST_ORDINAL(249);
 #endif
 
 #ifdef __cplusplus
diff --git a/thirdparty/libpng/pngconf.h b/thirdparty/libpng/pngconf.h
index 9308d6a60a..c0f15547be 100644
--- a/thirdparty/libpng/pngconf.h
+++ b/thirdparty/libpng/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.31rc01, July 19, 2017
+ * libpng version 1.6.32, August 24, 2017
  *
  * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
diff --git a/thirdparty/libpng/pngerror.c b/thirdparty/libpng/pngerror.c
index 37f26c6558..ad48bfb986 100644
--- a/thirdparty/libpng/pngerror.c
+++ b/thirdparty/libpng/pngerror.c
@@ -1,7 +1,7 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.31 [July 27, 2017]
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/thirdparty/libpng/pngget.c b/thirdparty/libpng/pngget.c
index ace9e6351f..26e9fb1c35 100644
--- a/thirdparty/libpng/pngget.c
+++ b/thirdparty/libpng/pngget.c
@@ -1,8 +1,8 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.6.26 [October 20, 2016]
- * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -778,11 +778,22 @@ png_uint_32 PNGAPI
 png_get_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
     png_bytep *exif)
 {
+  png_warning(png_ptr, "png_get_eXIf does not work; use png_get_eXIf_1");
+  PNG_UNUSED(info_ptr)
+  PNG_UNUSED(exif)
+  return 0;
+}
+
+png_uint_32 PNGAPI
+png_get_eXIf_1(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_uint_32 *num_exif, png_bytep *exif)
+{
    png_debug1(1, "in %s retrieval function", "eXIf");
 
    if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->valid & PNG_INFO_eXIf) != 0 && exif != NULL)
    {
+      *num_exif = info_ptr->num_exif;
       *exif = info_ptr->exif;
       return (PNG_INFO_eXIf);
    }
diff --git a/thirdparty/libpng/pnginfo.h b/thirdparty/libpng/pnginfo.h
index 6e6d46a62b..d5f6149dbd 100644
--- a/thirdparty/libpng/pnginfo.h
+++ b/thirdparty/libpng/pnginfo.h
@@ -186,8 +186,11 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
 #endif
 
 #ifdef PNG_eXIf_SUPPORTED
-   int num_exif;
+   int num_exif;  /* Added at libpng-1.6.31 */
    png_bytep exif;
+# ifdef PNG_READ_eXIf_SUPPORTED
+   png_bytep eXIf_buf;  /* Added at libpng-1.6.32 */
+# endif
 #endif
 
 #ifdef PNG_hIST_SUPPORTED
diff --git a/thirdparty/libpng/pnglibconf.h b/thirdparty/libpng/pnglibconf.h
index 8738ebdfc2..9e45f73129 100644
--- a/thirdparty/libpng/pnglibconf.h
+++ b/thirdparty/libpng/pnglibconf.h
@@ -1,8 +1,8 @@
-/* libpng 1.6.31rc01 STANDARD API DEFINITION */
+/* libpng 1.6.32 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.31rc01 - July 19, 2017 */
+/* Libpng version 1.6.32 - August 24, 2017 */
 
 /* Copyright (c) 1998-2017 Glenn Randers-Pehrson */
 
diff --git a/thirdparty/libpng/pngpread.c b/thirdparty/libpng/pngpread.c
index 650ba1e232..fbe361dc34 100644
--- a/thirdparty/libpng/pngpread.c
+++ b/thirdparty/libpng/pngpread.c
@@ -1,8 +1,8 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -189,6 +189,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
       png_crc_read(png_ptr, chunk_tag, 4);
       png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
       png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+      png_check_chunk_length(png_ptr, png_ptr->push_length);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
    }
 
diff --git a/thirdparty/libpng/pngpriv.h b/thirdparty/libpng/pngpriv.h
index 7c273bd5e3..1f2e90f2b3 100644
--- a/thirdparty/libpng/pngpriv.h
+++ b/thirdparty/libpng/pngpriv.h
@@ -1,7 +1,7 @@
 
 /* pngpriv.h - private declarations for use inside libpng
  *
- * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.32 [August 24, 2017]
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1143,6 +1143,11 @@ PNG_INTERNAL_FUNCTION(void,png_write_sRGB,(png_structrp png_ptr,
     int intent),PNG_EMPTY);
 #endif
 
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+PNG_INTERNAL_FUNCTION(void,png_write_eXIf,(png_structrp png_ptr,
+    png_bytep exif, int num_exif),PNG_EMPTY);
+#endif
+
 #ifdef PNG_WRITE_iCCP_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_write_iCCP,(png_structrp png_ptr,
    png_const_charp name, png_const_bytep profile), PNG_EMPTY);
@@ -1522,8 +1527,11 @@ PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
 #endif
 
-PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
-    png_uint_32 chunk_name),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_const_structrp png_ptr,
+    const png_uint_32 chunk_name),PNG_EMPTY);
+
+PNG_INTERNAL_FUNCTION(void,png_check_chunk_length,(png_const_structrp png_ptr,
+    const png_uint_32 chunk_length),PNG_EMPTY);
 
 PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
diff --git a/thirdparty/libpng/pngread.c b/thirdparty/libpng/pngread.c
index b44d4dfbb5..e34ddd99a0 100644
--- a/thirdparty/libpng/pngread.c
+++ b/thirdparty/libpng/pngread.c
@@ -1,7 +1,7 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.32 [August 24, 2017]
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -175,6 +175,11 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr)
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 
+#ifdef PNG_READ_eXIf_SUPPORTED
+      else if (chunk_name == png_eXIf)
+         png_handle_eXIf(png_ptr, info_ptr, length);
+#endif
+
 #ifdef PNG_READ_gAMA_SUPPORTED
       else if (chunk_name == png_gAMA)
          png_handle_gAMA(png_ptr, info_ptr, length);
@@ -534,6 +539,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
       png_error(png_ptr, "Invalid attempt to read row data");
 
    /* Fill the row with IDAT data: */
+   png_ptr->row_buf[0]=255; /* to force error if no data was found */
    png_read_IDAT_data(png_ptr, png_ptr->row_buf, row_info.rowbytes + 1);
 
    if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE)
@@ -842,6 +848,11 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 
+#ifdef PNG_READ_eXIf_SUPPORTED
+      else if (chunk_name == png_eXIf)
+         png_handle_eXIf(png_ptr, info_ptr, length);
+#endif
+
 #ifdef PNG_READ_gAMA_SUPPORTED
       else if (chunk_name == png_gAMA)
          png_handle_gAMA(png_ptr, info_ptr, length);
diff --git a/thirdparty/libpng/pngrtran.c b/thirdparty/libpng/pngrtran.c
index 9285983848..9a30ddf22b 100644
--- a/thirdparty/libpng/pngrtran.c
+++ b/thirdparty/libpng/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.31 [July 27, 2017]
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
diff --git a/thirdparty/libpng/pngrutil.c b/thirdparty/libpng/pngrutil.c
index 9cde64845c..a4fa71457b 100644
--- a/thirdparty/libpng/pngrutil.c
+++ b/thirdparty/libpng/pngrutil.c
@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.32 [August 24, 2017]
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -181,6 +181,9 @@ png_read_chunk_header(png_structrp png_ptr)
    /* Check to see if chunk name is valid. */
    png_check_chunk_name(png_ptr, png_ptr->chunk_name);
 
+   /* Check for too-large chunk length */
+   png_check_chunk_length(png_ptr, length);
+
 #ifdef PNG_IO_STATE_SUPPORTED
    png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
 #endif
@@ -1377,11 +1380,13 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
     * chunk is just ignored, so does not invalidate the color space.  An
     * alternative is to set the 'invalid' flags at the start of this routine
     * and only clear them in they were not set before and all the tests pass.
-    * The minimum 'deflate' stream is assumed to be just the 2 byte header and
-    * 4 byte checksum.  The keyword must be at least one character and there is
-    * a terminator (0) byte and the compression method.
     */
-   if (length < 9)
+
+   /* The keyword must be at least one character and there is a
+    * terminator (0) byte and the compression method byte, and the
+    * 'zlib' datastream is at least 11 bytes.
+    */
+   if (length < 14)
    {
       png_crc_finish(png_ptr, length);
       png_chunk_benign_error(png_ptr, "too short");
@@ -1413,6 +1418,16 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
       png_crc_read(png_ptr, (png_bytep)keyword, read_length);
       length -= read_length;
 
+      /* The minimum 'zlib' stream is assumed to be just the 2 byte header,
+       * 5 bytes minimum 'deflate' stream, and the 4 byte checksum.
+       */
+      if (length < 11)
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "too short");
+         return;
+      }
+
       keyword_length = 0;
       while (keyword_length < 80 && keyword_length < read_length &&
          keyword[keyword_length] != 0)
@@ -1431,7 +1446,7 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
 
             if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK)
             {
-               Byte profile_header[132];
+               Byte profile_header[132]={0};
                Byte local_buffer[PNG_INFLATE_BUF_SIZE];
                png_alloc_size_t size = (sizeof profile_header);
 
@@ -2014,36 +2029,61 @@ void /* PRIVATE */
 png_handle_eXIf(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
 {
    unsigned int i;
-   png_bytep eXIf_buf;
 
    png_debug(1, "in png_handle_eXIf");
 
    if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
       png_chunk_error(png_ptr, "missing IHDR");
 
-   else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_eXIf) != 0)
+   if (length < 2)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "too short");
+      return;
+   }
+
+   else if (info_ptr == NULL || (info_ptr->valid & PNG_INFO_eXIf) != 0)
    {
       png_crc_finish(png_ptr, length);
       png_chunk_benign_error(png_ptr, "duplicate");
       return;
    }
 
-   eXIf_buf = png_voidcast(png_bytep,
+   info_ptr->free_me |= PNG_FREE_EXIF;
+
+   info_ptr->eXIf_buf = png_voidcast(png_bytep,
              png_malloc_warn(png_ptr, length));
 
+   if (info_ptr->eXIf_buf == NULL)
+   {
+      png_crc_finish(png_ptr, length);
+      png_chunk_benign_error(png_ptr, "out of memory");
+      return;
+   }
+
    for (i = 0; i < length; i++)
    {
       png_byte buf[1];
       png_crc_read(png_ptr, buf, 1);
-      eXIf_buf[i] = buf[0];
+      info_ptr->eXIf_buf[i] = buf[0];
+      if (i == 1 && buf[0] != 'M' && buf[0] != 'I'
+                 && info_ptr->eXIf_buf[0] != buf[0])
+      {
+         png_crc_finish(png_ptr, length);
+         png_chunk_benign_error(png_ptr, "incorrect byte-order specifier");
+         png_free(png_ptr, info_ptr->eXIf_buf);
+         info_ptr->eXIf_buf = NULL;
+         return;
+      }
    }
 
    if (png_crc_finish(png_ptr, 0) != 0)
       return;
 
-   info_ptr->num_exif = length;
+   png_set_eXIf_1(png_ptr, info_ptr, length, info_ptr->eXIf_buf);
 
-   png_set_eXIf(png_ptr, info_ptr, eXIf_buf);
+   png_free(png_ptr, info_ptr->eXIf_buf);
+   info_ptr->eXIf_buf = NULL;
 }
 #endif
 
@@ -2624,23 +2664,28 @@ png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
       {
          png_text text;
 
-         /* It worked; png_ptr->read_buffer now looks like a tEXt chunk except
-          * for the extra compression type byte and the fact that it isn't
-          * necessarily '\0' terminated.
-          */
-         buffer = png_ptr->read_buffer;
-         buffer[uncompressed_length+(keyword_length+2)] = 0;
-
-         text.compression = PNG_TEXT_COMPRESSION_zTXt;
-         text.key = (png_charp)buffer;
-         text.text = (png_charp)(buffer + keyword_length+2);
-         text.text_length = uncompressed_length;
-         text.itxt_length = 0;
-         text.lang = NULL;
-         text.lang_key = NULL;
-
-         if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0)
-            errmsg = "insufficient memory";
+         if (png_ptr->read_buffer == NULL)
+           errmsg="Read failure in png_handle_zTXt";
+         else
+         {
+            /* It worked; png_ptr->read_buffer now looks like a tEXt chunk
+             * except for the extra compression type byte and the fact that
+             * it isn't necessarily '\0' terminated.
+             */
+            buffer = png_ptr->read_buffer;
+            buffer[uncompressed_length+(keyword_length+2)] = 0;
+
+            text.compression = PNG_TEXT_COMPRESSION_zTXt;
+            text.key = (png_charp)buffer;
+            text.text = (png_charp)(buffer + keyword_length+2);
+            text.text_length = uncompressed_length;
+            text.itxt_length = 0;
+            text.lang = NULL;
+            text.lang_key = NULL;
+
+            if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0)
+               errmsg = "insufficient memory";
+         }
       }
 
       else
@@ -3076,20 +3121,58 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
  */
 
 void /* PRIVATE */
-png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name)
+png_check_chunk_name(png_const_structrp png_ptr, const png_uint_32 chunk_name)
 {
    int i;
+   png_uint_32 cn=chunk_name;
 
    png_debug(1, "in png_check_chunk_name");
 
    for (i=1; i<=4; ++i)
    {
-      int c = chunk_name & 0xff;
+      int c = cn & 0xff;
 
       if (c < 65 || c > 122 || (c > 90 && c < 97))
          png_chunk_error(png_ptr, "invalid chunk type");
 
-      chunk_name >>= 8;
+      cn >>= 8;
+   }
+}
+
+void /* PRIVATE */
+png_check_chunk_length(png_const_structrp png_ptr, const png_uint_32 length)
+{
+   png_alloc_size_t limit = PNG_UINT_31_MAX;
+
+   if (png_ptr->chunk_name != png_IDAT)
+   {
+# ifdef PNG_SET_USER_LIMITS_SUPPORTED
+      if (png_ptr->user_chunk_malloc_max > 0 &&
+          png_ptr->user_chunk_malloc_max < limit)
+         limit = png_ptr->user_chunk_malloc_max;
+# elif PNG_USER_CHUNK_MALLOC_MAX > 0
+      if (PNG_USER_CHUNK_MALLOC_MAX < limit)
+         limit = PNG_USER_CHUNK_MALLOC_MAX;
+# endif
+   }
+   else
+   {
+      size_t row_factor =
+         (png_ptr->width * png_ptr->channels * (png_ptr->bit_depth > 8? 2: 1)
+          + 1 + (png_ptr->interlaced? 6: 0));
+      if (png_ptr->height > PNG_UINT_32_MAX/row_factor)
+         limit=PNG_UINT_31_MAX;
+      else
+         limit = png_ptr->height * row_factor;
+      limit += 6 + 5*(limit/32566+1); /* zlib+deflate overhead */
+      limit=limit < PNG_UINT_31_MAX? limit : PNG_UINT_31_MAX;
+   }
+
+   if (length > limit)
+   {
+      png_debug2(0," length = %lu, limit = %lu",
+         (unsigned long)length,(unsigned long)limit);
+      png_chunk_error(png_ptr, "chunk data is too large");
    }
 }
 
diff --git a/thirdparty/libpng/pngset.c b/thirdparty/libpng/pngset.c
index 998473557f..6f3a1ee11e 100644
--- a/thirdparty/libpng/pngset.c
+++ b/thirdparty/libpng/pngset.c
@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.6.30 [June 28, 2017]
+ * Last changed in libpng 1.6.32 [August 24, 2017]
  * Copyright (c) 1998-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -139,6 +139,15 @@ void PNGAPI
 png_set_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
     const png_bytep eXIf_buf)
 {
+  png_warning(png_ptr, "png_set_eXIf does not work; use png_set_eXIf_1");
+  PNG_UNUSED(info_ptr)
+  PNG_UNUSED(eXIf_buf)
+}
+
+void PNGAPI
+png_set_eXIf_1(png_const_structrp png_ptr, png_inforp info_ptr,
+    const png_uint_32 num_exif, const png_bytep eXIf_buf)
+{
    int i;
 
    png_debug1(1, "in %s storage function", "eXIf");
@@ -146,7 +155,13 @@ png_set_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   png_free_data(png_ptr, info_ptr, PNG_FREE_EXIF, 0);
+   if (info_ptr->exif)
+   {
+      png_free(png_ptr, info_ptr->exif);
+      info_ptr->exif = NULL;
+   }
+
+   info_ptr->num_exif = num_exif;
 
    info_ptr->exif = png_voidcast(png_bytep, png_malloc_warn(png_ptr,
        info_ptr->num_exif));
@@ -154,13 +169,12 @@ png_set_eXIf(png_const_structrp png_ptr, png_inforp info_ptr,
    if (info_ptr->exif == NULL)
    {
       png_warning(png_ptr, "Insufficient memory for eXIf chunk data");
-
       return;
    }
 
    info_ptr->free_me |= PNG_FREE_EXIF;
 
-   for (i = 0; i < info_ptr->num_exif; i++)
+   for (i = 0; i < (int) info_ptr->num_exif; i++)
       info_ptr->exif[i] = eXIf_buf[i];
 
    info_ptr->valid |= PNG_INFO_eXIf;
@@ -1388,6 +1402,7 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
       static PNG_CONST png_byte chunks_to_ignore[] = {
          98,  75,  71,  68, '\0',  /* bKGD */
          99,  72,  82,  77, '\0',  /* cHRM */
+        101,  88,  73, 102, '\0',  /* eXIf */
         103,  65,  77,  65, '\0',  /* gAMA */
         104,  73,  83,  84, '\0',  /* hIST */
         105,  67,  67,  80, '\0',  /* iCCP */
diff --git a/thirdparty/libpng/pngstruct.h b/thirdparty/libpng/pngstruct.h
index 44b79dea74..d83f971253 100644
--- a/thirdparty/libpng/pngstruct.h
+++ b/thirdparty/libpng/pngstruct.h
@@ -1,7 +1,7 @@
 
 /* pngstruct.h - header file for PNG reference library
  *
- * Last changed in libpng 1.6.28 [January 5, 2017]
+ * Last changed in libpng 1.6.32 [August 24, 2017]
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -479,8 +479,5 @@ struct png_struct_def
    png_colorspace   colorspace;
 #endif
 #endif
-
-/* New member added in libpng-1.6.31 */
-   int num_exif;
 };
 #endif /* PNGSTRUCT_H */
diff --git a/thirdparty/libpng/pngwrite.c b/thirdparty/libpng/pngwrite.c
index 8c2952e794..a7662acb71 100644
--- a/thirdparty/libpng/pngwrite.c
+++ b/thirdparty/libpng/pngwrite.c
@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.6.31 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.32 [August 24, 2017]
  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -237,6 +237,11 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
       png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
 #endif
 
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_eXIf) != 0)
+      png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif);
+#endif
+
 #ifdef PNG_WRITE_hIST_SUPPORTED
    if ((info_ptr->valid & PNG_INFO_hIST) != 0)
       png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
@@ -432,6 +437,12 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
          }
       }
 #endif
+
+#ifdef PNG_WRITE_eXIf_SUPPORTED
+   if ((info_ptr->valid & PNG_INFO_eXIf) != 0)
+      png_write_eXIf(png_ptr, info_ptr->exif, info_ptr->num_exif);
+#endif
+
 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
       write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT);
 #endif
diff --git a/thirdparty/libpng/pngwutil.c b/thirdparty/libpng/pngwutil.c
index 348bb524dd..0d4fb1336c 100644
--- a/thirdparty/libpng/pngwutil.c
+++ b/thirdparty/libpng/pngwutil.c
@@ -1,8 +1,8 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * Last changed in libpng 1.6.26 [October 20, 2016]
- * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.32 [August 24, 2017]
+ * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -1479,24 +1479,15 @@ void /* PRIVATE */
 png_write_eXIf(png_structrp png_ptr, png_bytep exif, int num_exif)
 {
    int i;
-   png_byte buf[3];
+   png_byte buf[1];
 
    png_debug(1, "in png_write_eXIf");
 
-   if (num_exif > (int)png_ptr->num_exif)
-   {
-      png_debug2(3, "num_exif = %d, png_ptr->num_exif = %d", num_exif,
-          png_ptr->num_exif);
-
-      png_warning(png_ptr, "Invalid number of exif bytes specified");
-      return;
-   }
-
    png_write_chunk_header(png_ptr, png_eXIf, (png_uint_32)(num_exif));
 
    for (i = 0; i < num_exif; i++)
    {
-      buf[i] = exif[i];
+      buf[0] = exif[i];
       png_write_chunk_data(png_ptr, buf, (png_size_t)1);
    }