libpng-32: 1.6.31 -> 1.6.32

5 files changed, 793 insertions, 876 deletions

diff --git a/libpng-32/.footprint b/libpng-32/.footprint
index 25a9ee00..ead683f0 100644
--- a/libpng-32/.footprint
+++ b/libpng-32/.footprint
@@ -5,9 +5,9 @@ lrwxrwxrwx	root/root	usr/lib32/libpng.la -> libpng16.la
 lrwxrwxrwx	root/root	usr/lib32/libpng.so -> libpng16.so
 -rw-r--r--	root/root	usr/lib32/libpng16.a
 -rwxr-xr-x	root/root	usr/lib32/libpng16.la
-lrwxrwxrwx	root/root	usr/lib32/libpng16.so -> libpng16.so.16.31.0
-lrwxrwxrwx	root/root	usr/lib32/libpng16.so.16 -> libpng16.so.16.31.0
--rwxr-xr-x	root/root	usr/lib32/libpng16.so.16.31.0
+lrwxrwxrwx	root/root	usr/lib32/libpng16.so -> libpng16.so.16.32.0
+lrwxrwxrwx	root/root	usr/lib32/libpng16.so.16 -> libpng16.so.16.32.0
+-rwxr-xr-x	root/root	usr/lib32/libpng16.so.16.32.0
 drwxr-xr-x	root/root	usr/lib32/pkgconfig/
 lrwxrwxrwx	root/root	usr/lib32/pkgconfig/libpng.pc -> libpng16.pc
 -rw-r--r--	root/root	usr/lib32/pkgconfig/libpng16.pc
diff --git a/libpng-32/.md5sum b/libpng-32/.md5sum
index d17f8dd5..ff0f822e 100644
--- a/libpng-32/.md5sum
+++ b/libpng-32/.md5sum
@@ -1,2 +1,2 @@
-1b34eab440263e32cfa39d19413fad54  libpng-1.6.31.tar.xz
-31d14c8a6cc867396756bb5ec5171057  libpng-apng.patch
+e01be057a9369183c959b793a685ad15  libpng-1.6.32.tar.xz
+f9d1e9861ad0da880ef1741e1b235c43  libpng-apng.patch
diff --git a/libpng-32/.signature b/libpng-32/.signature
index 3d697e27..9d39c377 100644
--- a/libpng-32/.signature
+++ b/libpng-32/.signature
@@ -1,6 +1,6 @@
 untrusted comment: verify with /etc/ports/compat-32.pub
-RWSwxGo/zH7eXUutx8keIMSump6iDtCkdYOhPZ6GWMbKt2VmXCR/JryfB5Nsv8AK3itxhukrQ2Tiun1yYuCB8D0O0anH9ebDkwI=
-SHA256 (Pkgfile) = af6e50b4e24d39a7a0fe85b20b433547b6b6b9614c245a75e529635c4462f15f
-SHA256 (.footprint) = 8948f623e547471ce3c8f6b2cf22ee842a86b41a791900bd0e5547067102413b
-SHA256 (libpng-1.6.31.tar.xz) = 232a602de04916b2b5ce6f901829caf419519e6a16cc9cd7c1c91187d3ee8b41
-SHA256 (libpng-apng.patch) = 95566a9ad4757d2ca37dcef36e903462dcec6bb6cd2181e6293bccedc74cc830
+RWSwxGo/zH7eXTkwp+mH1bQukiUAE04n9RvaD11No2QHWEUiJ6O+Kp6ElRTIhOmrh80aEcmU1EA60K2lKQlfGI/Hfb8DwJD/dwE=
+SHA256 (Pkgfile) = a4124a6cb488a57c5268c88f4125e3cc86ae48f9057efeea112ecbb1710ba2d0
+SHA256 (.footprint) = 847b0913f99172f462881cb291c11a417d92e2f547178e67835d5bae2056a4c0
+SHA256 (libpng-1.6.32.tar.xz) = c918c3113de74a692f0a1526ce881dc26067763eb3915c57ef3a0f7b6886f59b
+SHA256 (libpng-apng.patch) = 903eaae2c27a28f82fdcae8a1a73f05086d2bde2c6a99ceb351f8bdd738283a5
diff --git a/libpng-32/Pkgfile b/libpng-32/Pkgfile
index 8cee6b2a..cc4b8953 100644
--- a/libpng-32/Pkgfile
+++ b/libpng-32/Pkgfile
@@ -4,7 +4,7 @@
 # Depends on:  zlib-32 libpng
 
 name=libpng-32
-version=1.6.31
+version=1.6.32
 _base=${version:0:3}
 _base=${_base/./}
 release=1
@@ -14,7 +14,7 @@ source=(https://downloads.sourceforge.net/project/${name%-*}/${name%-*}$_base/$v
 build() {
 	cd ${name%-*}-$version
 
-	patch -p1 -i $SRC/libpng-apng.patch
+	patch -p0 -i $SRC/libpng-apng.patch
 
 	./configure \
 		--prefix=/usr \
diff --git a/libpng-32/libpng-apng.patch b/libpng-32/libpng-apng.patch
index 2bd2b5d9..3f6aadd3 100644
--- a/libpng-32/libpng-apng.patch
+++ b/libpng-32/libpng-apng.patch
@@ -1,148 +1,130 @@
-diff -Naru libpng-1.6.31.org/png.h libpng-1.6.31/png.h
---- libpng-1.6.31.org/png.h	2017-07-29 10:08:06.209574100 +0900
-+++ libpng-1.6.31/png.h	2017-07-29 10:50:19.591317483 +0900
-@@ -361,6 +361,10 @@
- #   include "pnglibconf.h"
- #endif
+Index: LICENSE
+===================================================================
+--- LICENSE
++++ LICENSE
+@@ -8,6 +8,12 @@
+ If you modify libpng you may insert additional notices immediately following
+ this sentence.
  
-+#define PNG_APNG_SUPPORTED
-+#define PNG_READ_APNG_SUPPORTED
-+#define PNG_WRITE_APNG_SUPPORTED
++This modified version of libpng code adds animated PNG support and is
++released under the libpng license described below. The modifications are
++Copyright (c) 2006-2007 Andrew Smith, Copyright (c) 2008-2017 Max Stepin,
++and are delimited by "#ifdef PNG_APNG_SUPPORTED / #endif" directives
++surrounding them in the modified libpng source files.
 +
- #ifndef PNG_VERSION_INFO_ONLY
- /* Machine specific configuration. */
- #  include "pngconf.h"
-@@ -456,6 +460,17 @@
-  * See pngconf.h for base types that vary by machine/system
-  */
+ This code is released under the libpng license.
  
-+#ifdef PNG_APNG_SUPPORTED
-+/* dispose_op flags from inside fcTL */
-+#define PNG_DISPOSE_OP_NONE        0x00U
-+#define PNG_DISPOSE_OP_BACKGROUND  0x01U
-+#define PNG_DISPOSE_OP_PREVIOUS    0x02U
-+
-+/* blend_op flags from inside fcTL */
-+#define PNG_BLEND_OP_SOURCE        0x00U
-+#define PNG_BLEND_OP_OVER          0x01U
-+#endif /* PNG_APNG_SUPPORTED */
-+
- /* This triggers a compiler error in png.c, if png.c and png.h
-  * do not agree upon the version number.
-  */
-@@ -777,6 +792,10 @@
- #define PNG_INFO_sCAL 0x4000U  /* ESR, 1.0.6 */
- #define PNG_INFO_IDAT 0x8000U  /* ESR, 1.0.6 */
- #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
-+#ifdef PNG_APNG_SUPPORTED
-+#define PNG_INFO_acTL 0x20000U
-+#define PNG_INFO_fcTL 0x40000U
+ libpng versions 1.0.7, July 1, 2000 through 1.6.32, August 24, 2017 are
+Index: pngread.c
+===================================================================
+--- pngread.c
++++ pngread.c
+@@ -161,6 +161,9 @@
+ 
+       else if (chunk_name == png_IDAT)
+       {
++#ifdef PNG_READ_APNG_SUPPORTED
++         png_have_info(png_ptr, info_ptr);
 +#endif
+          png_ptr->idat_size = length;
+          break;
+       }
+@@ -255,6 +258,17 @@
+          png_handle_iTXt(png_ptr, info_ptr, length);
+ #endif
  
- /* This is used for the transformation routines, as some of them
-  * change these values for the row.  It also should enable using
-@@ -814,6 +833,10 @@
- #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
- typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
- typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
-+#ifdef PNG_APNG_SUPPORTED
-+typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp,
-+    png_uint_32));
++#ifdef PNG_READ_APNG_SUPPORTED
++      else if (chunk_name == png_acTL)
++         png_handle_acTL(png_ptr, info_ptr, length);
++
++      else if (chunk_name == png_fcTL)
++         png_handle_fcTL(png_ptr, info_ptr, length);
++
++      else if (chunk_name == png_fdAT)
++         png_handle_fdAT(png_ptr, info_ptr, length);
 +#endif
++
+       else
+          png_handle_unknown(png_ptr, info_ptr, length,
+              PNG_HANDLE_CHUNK_AS_DEFAULT);
+@@ -262,6 +276,72 @@
+ }
+ #endif /* SEQUENTIAL_READ */
  
- /* The following callback receives png_uint_32 row_number, int pass for the
-  * png_bytep data of the row.  When transforming an interlaced image the
-@@ -3250,6 +3273,74 @@
- /*******************************************************************************
-  *  END OF HARDWARE AND SOFTWARE OPTIONS
-  ******************************************************************************/
-+#ifdef PNG_APNG_SUPPORTED
-+PNG_EXPORT(248, png_uint_32, png_get_acTL, (png_structp png_ptr,
-+   png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays));
++#ifdef PNG_READ_APNG_SUPPORTED
++void PNGAPI
++png_read_frame_head(png_structp png_ptr, png_infop info_ptr)
++{
++    png_byte have_chunk_after_DAT; /* after IDAT or after fdAT */
 +
-+PNG_EXPORT(249, png_uint_32, png_set_acTL, (png_structp png_ptr,
-+   png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays));
++    png_debug(0, "Reading frame head");
 +
-+PNG_EXPORT(250, png_uint_32, png_get_num_frames, (png_structp png_ptr,
-+   png_infop info_ptr));
++    if ((png_ptr->mode & PNG_HAVE_acTL) == 0)
++        png_error(png_ptr, "attempt to png_read_frame_head() but "
++                           "no acTL present");
 +
-+PNG_EXPORT(251, png_uint_32, png_get_num_plays, (png_structp png_ptr,
-+   png_infop info_ptr));
++    /* do nothing for the main IDAT */
++    if (png_ptr->num_frames_read == 0)
++        return;
 +
-+PNG_EXPORT(252, png_uint_32, png_get_next_frame_fcTL,
-+   (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width,
-+   png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset,
-+   png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op,
-+   png_byte *blend_op));
++    png_read_reset(png_ptr);
++    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
++    png_ptr->mode &= ~PNG_HAVE_fcTL;
 +
-+PNG_EXPORT(253, png_uint_32, png_set_next_frame_fcTL,
-+   (png_structp png_ptr, png_infop info_ptr, png_uint_32 width,
-+   png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset,
-+   png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
-+   png_byte blend_op));
++    have_chunk_after_DAT = 0;
++    for (;;)
++    {
++        png_uint_32 length = png_read_chunk_header(png_ptr);
 +
-+PNG_EXPORT(254, png_uint_32, png_get_next_frame_width,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(255, png_uint_32, png_get_next_frame_height,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(256, png_uint_32, png_get_next_frame_x_offset,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(257, png_uint_32, png_get_next_frame_y_offset,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(258, png_uint_16, png_get_next_frame_delay_num,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(259, png_uint_16, png_get_next_frame_delay_den,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(260, png_byte, png_get_next_frame_dispose_op,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(261, png_byte, png_get_next_frame_blend_op,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(262, png_byte, png_get_first_frame_is_hidden,
-+   (png_structp png_ptr, png_infop info_ptr));
-+PNG_EXPORT(263, png_uint_32, png_set_first_frame_is_hidden,
-+   (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden));
++        if (png_ptr->chunk_name == png_IDAT)
++        {
++            /* discard trailing IDATs for the first frame */
++            if (have_chunk_after_DAT != 0 || png_ptr->num_frames_read > 1)
++                png_error(png_ptr, "png_read_frame_head(): out of place IDAT");
++            png_crc_finish(png_ptr, length);
++        }
 +
-+#ifdef PNG_READ_APNG_SUPPORTED
-+PNG_EXPORT(264, void, png_read_frame_head, (png_structp png_ptr,
-+   png_infop info_ptr));
-+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-+PNG_EXPORT(265, void, png_set_progressive_frame_fn, (png_structp png_ptr,
-+   png_progressive_frame_ptr frame_info_fn,
-+   png_progressive_frame_ptr frame_end_fn));
-+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-+#endif /* PNG_READ_APNG_SUPPORTED */
++        else if (png_ptr->chunk_name == png_fcTL)
++        {
++            png_handle_fcTL(png_ptr, info_ptr, length);
++            have_chunk_after_DAT = 1;
++        }
 +
-+#ifdef PNG_WRITE_APNG_SUPPORTED
-+PNG_EXPORT(266, void, png_write_frame_head, (png_structp png_ptr,
-+   png_infop info_ptr, png_bytepp row_pointers,
-+   png_uint_32 width, png_uint_32 height,
-+   png_uint_32 x_offset, png_uint_32 y_offset,
-+   png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
-+   png_byte blend_op));
++        else if (png_ptr->chunk_name == png_fdAT)
++        {
++            png_ensure_sequence_number(png_ptr, length);
 +
-+PNG_EXPORT(267, void, png_write_frame_tail, (png_structp png_ptr,
-+   png_infop info_ptr));
-+#endif /* PNG_WRITE_APNG_SUPPORTED */
-+#endif /* PNG_APNG_SUPPORTED */
- 
- /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
-  * defs, and in scripts/symbols.def.
-@@ -3259,7 +3350,11 @@
-  * one to use is one more than this.)
-  */
- #ifdef PNG_EXPORT_LAST_ORDINAL
-+#ifdef PNG_APNG_SUPPORTED
-+  PNG_EXPORT_LAST_ORDINAL(267);
-+#else
-   PNG_EXPORT_LAST_ORDINAL(247);
-+#endif /* PNG_APNG_SUPPORTED */
- #endif
- 
- #ifdef __cplusplus
-diff -Naru libpng-1.6.31.org/pngget.c libpng-1.6.31/pngget.c
---- libpng-1.6.31.org/pngget.c	2017-07-29 10:08:06.209574100 +0900
-+++ libpng-1.6.31/pngget.c	2017-07-29 10:50:19.582316721 +0900
-@@ -1234,4 +1234,166 @@
++            /* discard trailing fdATs for frames other than the first */
++            if (have_chunk_after_DAT == 0 && png_ptr->num_frames_read > 1)
++                png_crc_finish(png_ptr, length - 4);
++            else if (png_ptr->mode & PNG_HAVE_fcTL)
++            {
++                png_ptr->idat_size = length - 4;
++                png_ptr->mode |= PNG_HAVE_IDAT;
++
++                break;
++            }
++            else
++                png_error(png_ptr, "png_read_frame_head(): out of place fdAT");
++        }
++        else
++        {
++            png_warning(png_ptr, "Skipped (ignored) a chunk "
++                                 "between APNG chunks");
++            png_crc_finish(png_ptr, length);
++        }
++    }
++}
++#endif /* READ_APNG */
++
+ /* Optional call to update the users info_ptr structure */
+ void PNGAPI
+ png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
+Index: pngget.c
+===================================================================
+--- pngget.c
++++ pngget.c
+@@ -1245,4 +1245,166 @@
  #  endif
  #endif
  
@@ -154,7 +136,7 @@ diff -Naru libpng-1.6.31.org/pngget.c libpng-1.6.31/pngget.c
 +    png_debug1(1, "in %s retrieval function", "acTL");
 +
 +    if (png_ptr != NULL && info_ptr != NULL &&
-+        (info_ptr->valid & PNG_INFO_acTL) &&
++        (info_ptr->valid & PNG_INFO_acTL) != 0 &&
 +        num_frames != NULL && num_plays != NULL)
 +    {
 +        *num_frames = info_ptr->num_frames;
@@ -195,7 +177,7 @@ diff -Naru libpng-1.6.31.org/pngget.c libpng-1.6.31/pngget.c
 +    png_debug1(1, "in %s retrieval function", "fcTL");
 +
 +    if (png_ptr != NULL && info_ptr != NULL &&
-+        (info_ptr->valid & PNG_INFO_fcTL) &&
++        (info_ptr->valid & PNG_INFO_fcTL) != 0 &&
 +        width != NULL && height != NULL &&
 +        x_offset != NULL && y_offset != NULL &&
 +        delay_num != NULL && delay_den != NULL &&
@@ -307,12 +289,293 @@ diff -Naru libpng-1.6.31.org/pngget.c libpng-1.6.31/pngget.c
 +
 +    return 0;
 +}
-+#endif /* PNG_APNG_SUPPORTED */
++#endif /* APNG */
  #endif /* READ || WRITE */
-diff -Naru libpng-1.6.31.org/pnginfo.h libpng-1.6.31/pnginfo.h
---- libpng-1.6.31.org/pnginfo.h	2017-07-29 10:08:06.210574185 +0900
-+++ libpng-1.6.31/pnginfo.h	2017-07-29 10:50:19.582316721 +0900
-@@ -260,5 +260,18 @@
+Index: png.c
+===================================================================
+--- png.c
++++ png.c
+@@ -816,17 +816,21 @@
+ #else
+ #  ifdef __STDC__
+    return PNG_STRING_NEWLINE \
+-      "libpng version 1.6.32 - August 24, 2017" PNG_STRING_NEWLINE \
++      "libpng version 1.6.32+apng - 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;
++      PNG_STRING_NEWLINE \
++      "Portions Copyright (c) 2006-2007 Andrew Smith" PNG_STRING_NEWLINE \
++      "Portions Copyright (c) 2008-2017 Max Stepin" PNG_STRING_NEWLINE ;
+ #  else
+-   return "libpng version 1.6.32 - August 24, 2017\
++   return "libpng version 1.6.32+apng - 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.";
++      Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\
++      Portions Copyright (c) 2006-2007 Andrew Smith\
++      Portions Copyright (c) 2008-2017 Max Stepin";
+ #  endif
+ #endif
+ }
+Index: png.h
+===================================================================
+--- png.h
++++ png.h
+@@ -23,6 +23,12 @@
+  * If you modify libpng you may insert additional notices immediately following
+  * this sentence.
+  *
++ * This modified version of libpng code adds animated PNG support and is
++ * released under the libpng license described below. The modifications are
++ * Copyright (c) 2006-2007 Andrew Smith, Copyright (c) 2008-2017 Max Stepin,
++ * and are delimited by "#ifdef PNG_APNG_SUPPORTED / #endif" directives
++ * surrounding them in the modified libpng source files.
++ *
+  * This code is released under the libpng license.
+  *
+  * libpng versions 1.0.7, July 1, 2000 through 1.6.32, August 24, 2017 are
+@@ -309,8 +315,9 @@
+  */
+ 
+ /* Version information for png.h - this should match the version in png.c */
+-#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_STRING "1.6.32+apng"
++#define PNG_HEADER_VERSION_STRING \
++     " libpng version 1.6.32+apng - August 24, 2017\n"
+ 
+ #define PNG_LIBPNG_VER_SONUM   16
+ #define PNG_LIBPNG_VER_DLLNUM  16
+@@ -361,6 +368,10 @@
+ #   include "pnglibconf.h"
+ #endif
+ 
++#define PNG_APNG_SUPPORTED
++#define PNG_READ_APNG_SUPPORTED
++#define PNG_WRITE_APNG_SUPPORTED
++
+ #ifndef PNG_VERSION_INFO_ONLY
+ /* Machine specific configuration. */
+ #  include "pngconf.h"
+@@ -456,6 +467,17 @@
+  * See pngconf.h for base types that vary by machine/system
+  */
+ 
++#ifdef PNG_APNG_SUPPORTED
++/* dispose_op flags from inside fcTL */
++#define PNG_DISPOSE_OP_NONE        0x00
++#define PNG_DISPOSE_OP_BACKGROUND  0x01
++#define PNG_DISPOSE_OP_PREVIOUS    0x02
++
++/* blend_op flags from inside fcTL */
++#define PNG_BLEND_OP_SOURCE        0x00
++#define PNG_BLEND_OP_OVER          0x01
++#endif /* APNG */
++
+ /* This triggers a compiler error in png.c, if png.c and png.h
+  * do not agree upon the version number.
+  */
+@@ -777,6 +799,10 @@
+ #define PNG_INFO_sCAL 0x4000U  /* ESR, 1.0.6 */
+ #define PNG_INFO_IDAT 0x8000U  /* ESR, 1.0.6 */
+ #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
++#ifdef PNG_APNG_SUPPORTED
++#define PNG_INFO_acTL 0x20000U
++#define PNG_INFO_fcTL 0x40000U
++#endif
+ 
+ /* This is used for the transformation routines, as some of them
+  * change these values for the row.  It also should enable using
+@@ -814,6 +840,10 @@
+ #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+ typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
+ typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
++#ifdef PNG_APNG_SUPPORTED
++typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp,
++    png_uint_32));
++#endif
+ 
+ /* The following callback receives png_uint_32 row_number, int pass for the
+  * png_bytep data of the row.  When transforming an interlaced image the
+@@ -3256,6 +3286,75 @@
+  *  END OF HARDWARE AND SOFTWARE OPTIONS
+  ******************************************************************************/
+ 
++#ifdef PNG_APNG_SUPPORTED
++PNG_EXPORT(248, png_uint_32, png_get_acTL, (png_structp png_ptr,
++   png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays));
++
++PNG_EXPORT(249, png_uint_32, png_set_acTL, (png_structp png_ptr,
++   png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays));
++
++PNG_EXPORT(250, png_uint_32, png_get_num_frames, (png_structp png_ptr,
++   png_infop info_ptr));
++
++PNG_EXPORT(251, png_uint_32, png_get_num_plays, (png_structp png_ptr,
++   png_infop info_ptr));
++
++PNG_EXPORT(252, png_uint_32, png_get_next_frame_fcTL,
++   (png_structp png_ptr, png_infop info_ptr, png_uint_32 *width,
++   png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset,
++   png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op,
++   png_byte *blend_op));
++
++PNG_EXPORT(253, png_uint_32, png_set_next_frame_fcTL,
++   (png_structp png_ptr, png_infop info_ptr, png_uint_32 width,
++   png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset,
++   png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++   png_byte blend_op));
++
++PNG_EXPORT(254, png_uint_32, png_get_next_frame_width,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(255, png_uint_32, png_get_next_frame_height,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(256, png_uint_32, png_get_next_frame_x_offset,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(257, png_uint_32, png_get_next_frame_y_offset,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(258, png_uint_16, png_get_next_frame_delay_num,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(259, png_uint_16, png_get_next_frame_delay_den,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(260, png_byte, png_get_next_frame_dispose_op,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(261, png_byte, png_get_next_frame_blend_op,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(262, png_byte, png_get_first_frame_is_hidden,
++   (png_structp png_ptr, png_infop info_ptr));
++PNG_EXPORT(263, png_uint_32, png_set_first_frame_is_hidden,
++   (png_structp png_ptr, png_infop info_ptr, png_byte is_hidden));
++
++#ifdef PNG_READ_APNG_SUPPORTED
++PNG_EXPORT(264, void, png_read_frame_head, (png_structp png_ptr,
++   png_infop info_ptr));
++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
++PNG_EXPORT(265, void, png_set_progressive_frame_fn, (png_structp png_ptr,
++   png_progressive_frame_ptr frame_info_fn,
++   png_progressive_frame_ptr frame_end_fn));
++#endif /* PROGRESSIVE_READ */
++#endif /* READ_APNG */
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++PNG_EXPORT(266, void, png_write_frame_head, (png_structp png_ptr,
++   png_infop info_ptr, png_bytepp row_pointers,
++   png_uint_32 width, png_uint_32 height,
++   png_uint_32 x_offset, png_uint_32 y_offset,
++   png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++   png_byte blend_op));
++
++PNG_EXPORT(267, void, png_write_frame_tail, (png_structp png_ptr,
++   png_infop info_ptr));
++#endif /* WRITE_APNG */
++#endif /* APNG */
++
+ /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
+  * defs, and in scripts/symbols.def.
+  */
+@@ -3264,7 +3363,11 @@
+  * one to use is one more than this.)
+  */
+ #ifdef PNG_EXPORT_LAST_ORDINAL
++#ifdef PNG_APNG_SUPPORTED
++  PNG_EXPORT_LAST_ORDINAL(269);
++#else
+   PNG_EXPORT_LAST_ORDINAL(249);
++#endif /* APNG */
+ #endif
+ 
+ #ifdef __cplusplus
+Index: pngpriv.h
+===================================================================
+--- pngpriv.h
++++ pngpriv.h
+@@ -628,6 +628,10 @@
+ #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
+                    /*             0x4000U (unused) */
+ #define PNG_IS_READ_STRUCT        0x8000U /* Else is a write struct */
++#ifdef PNG_APNG_SUPPORTED
++#define PNG_HAVE_acTL            0x10000U
++#define PNG_HAVE_fcTL            0x20000U
++#endif
+ 
+ /* Flags for the transformations the PNG library does on the image data */
+ #define PNG_BGR                 0x0001U
+@@ -864,6 +868,16 @@
+ #define png_tRNS PNG_U32(116,  82,  78,  83)
+ #define png_zTXt PNG_U32(122,  84,  88, 116)
+ 
++#ifdef PNG_APNG_SUPPORTED
++#define png_acTL PNG_U32( 97,  99,  84,  76)
++#define png_fcTL PNG_U32(102,  99,  84,  76)
++#define png_fdAT PNG_U32(102, 100,  65,  84)
++
++/* For png_struct.apng_flags: */
++#define PNG_FIRST_FRAME_HIDDEN       0x0001U
++#define PNG_APNG_APP                 0x0002U
++#endif
++
+ /* The following will work on (signed char*) strings, whereas the get_uint_32
+  * macro will fail on top-bit-set values because of the sign extension.
+  */
+@@ -1615,6 +1629,49 @@
+ 
+ #endif /* PROGRESSIVE_READ */
+ 
++#ifdef PNG_APNG_SUPPORTED
++PNG_INTERNAL_FUNCTION(void,png_ensure_fcTL_is_valid,(png_structp png_ptr,
++   png_uint_32 width, png_uint_32 height,
++   png_uint_32 x_offset, png_uint_32 y_offset,
++   png_uint_16 delay_num, png_uint_16 delay_den,
++   png_byte dispose_op, png_byte blend_op),PNG_EMPTY);
++
++#ifdef PNG_READ_APNG_SUPPORTED
++PNG_INTERNAL_FUNCTION(void,png_handle_acTL,(png_structp png_ptr,
++   png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_handle_fcTL,(png_structp png_ptr,
++   png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_handle_fdAT,(png_structp png_ptr,
++   png_infop info_ptr, png_uint_32 length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_have_info,(png_structp png_ptr,
++   png_infop info_ptr),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_ensure_sequence_number,(png_structp png_ptr,
++   png_uint_32 length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_read_reset,(png_structp png_ptr),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_read_reinit,(png_structp png_ptr,
++   png_infop info_ptr),PNG_EMPTY);
++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
++PNG_INTERNAL_FUNCTION(void,png_progressive_read_reset,(png_structp png_ptr),
++   PNG_EMPTY);
++#endif /* PROGRESSIVE_READ */
++#endif /* READ_APNG */
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++PNG_INTERNAL_FUNCTION(void,png_write_acTL,(png_structp png_ptr,
++   png_uint_32 num_frames, png_uint_32 num_plays),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_write_fcTL,(png_structp png_ptr,
++   png_uint_32 width, png_uint_32 height,
++   png_uint_32 x_offset, png_uint_32 y_offset,
++   png_uint_16 delay_num, png_uint_16 delay_den,
++   png_byte dispose_op, png_byte blend_op),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_write_fdAT,(png_structp png_ptr,
++   png_const_bytep data, png_size_t length),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_write_reset,(png_structp png_ptr),PNG_EMPTY);
++PNG_INTERNAL_FUNCTION(void,png_write_reinit,(png_structp png_ptr,
++   png_infop info_ptr, png_uint_32 width, png_uint_32 height),PNG_EMPTY);
++#endif /* WRITE_APNG */
++#endif /* APNG */
++
+ /* Added at libpng version 1.6.0 */
+ #ifdef PNG_GAMMA_SUPPORTED
+ PNG_INTERNAL_FUNCTION(void,png_colorspace_set_gamma,(png_const_structrp png_ptr,
+Index: pnginfo.h
+===================================================================
+--- pnginfo.h
++++ pnginfo.h
+@@ -263,5 +263,18 @@
     png_bytepp row_pointers;        /* the image bits */
  #endif
  
@@ -331,10 +594,113 @@ diff -Naru libpng-1.6.31.org/pnginfo.h libpng-1.6.31/pnginfo.h
 +
  };
  #endif /* PNGINFO_H */
-diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
---- libpng-1.6.31.org/pngpread.c	2017-06-30 16:42:16.781952082 +0900
-+++ libpng-1.6.31/pngpread.c	2017-07-29 10:50:19.582316721 +0900
-@@ -194,6 +194,106 @@
+Index: pngstruct.h
+===================================================================
+--- pngstruct.h
++++ pngstruct.h
+@@ -403,6 +403,27 @@
+    png_byte filter_type;
+ #endif
+ 
++#ifdef PNG_APNG_SUPPORTED
++   png_uint_32 apng_flags;
++   png_uint_32 next_seq_num;         /* next fcTL/fdAT chunk sequence number */
++   png_uint_32 first_frame_width;
++   png_uint_32 first_frame_height;
++
++#ifdef PNG_READ_APNG_SUPPORTED
++   png_uint_32 num_frames_read;      /* incremented after all image data of */
++                                     /* a frame is read */
++#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
++   png_progressive_frame_ptr frame_info_fn; /* frame info read callback */
++   png_progressive_frame_ptr frame_end_fn;  /* frame data read callback */
++#endif
++#endif
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   png_uint_32 num_frames_to_write;
++   png_uint_32 num_frames_written;
++#endif
++#endif /* APNG */
++
+ /* New members added in libpng-1.2.0 */
+ 
+ /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
+Index: pngwrite.c
+===================================================================
+--- pngwrite.c
++++ pngwrite.c
+@@ -128,6 +128,10 @@
+        * the application continues writing the PNG.  So check the 'invalid'
+        * flag here too.
+        */
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   if ((info_ptr->valid & PNG_INFO_acTL) != 0)
++      png_write_acTL(png_ptr, info_ptr->num_frames, info_ptr->num_plays);
++#endif
+ #ifdef PNG_GAMMA_SUPPORTED
+ #  ifdef PNG_WRITE_gAMA_SUPPORTED
+       if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+@@ -365,6 +369,11 @@
+    if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
+       png_error(png_ptr, "No IDATs written into file");
+ 
++#ifdef PNG_WRITE_APNG_SUPPORTED
++   if (png_ptr->num_frames_written != png_ptr->num_frames_to_write)
++      png_error(png_ptr, "Not enough frames written");
++#endif
++
+ #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
+    if (png_ptr->num_palette_max > png_ptr->num_palette)
+       png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
+@@ -2393,4 +2402,42 @@
+ }
+ #endif /* SIMPLIFIED_WRITE_STDIO */
+ #endif /* SIMPLIFIED_WRITE */
++
++#ifdef PNG_WRITE_APNG_SUPPORTED
++void PNGAPI
++png_write_frame_head(png_structp png_ptr, png_infop info_ptr,
++    png_bytepp row_pointers, png_uint_32 width, png_uint_32 height,
++    png_uint_32 x_offset, png_uint_32 y_offset,
++    png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
++    png_byte blend_op)
++{
++    png_debug(1, "in png_write_frame_head");
++
++    /* there is a chance this has been set after png_write_info was called,
++    * so it would be set but not written. is there a way to be sure? */
++    if ((info_ptr->valid & PNG_INFO_acTL) == 0)
++        png_error(png_ptr, "png_write_frame_head(): acTL not set");
++
++    png_write_reset(png_ptr);
++
++    png_write_reinit(png_ptr, info_ptr, width, height);
++
++    if ((png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) == 0 ||
++        png_ptr->num_frames_written != 0)
++        png_write_fcTL(png_ptr, width, height, x_offset, y_offset,
++                       delay_num, delay_den, dispose_op, blend_op);
++
++    PNG_UNUSED(row_pointers)
++}
++
++void PNGAPI
++png_write_frame_tail(png_structp png_ptr, png_infop info_ptr)
++{
++    png_debug(1, "in png_write_frame_tail");
++
++    png_ptr->num_frames_written++;
++
++    PNG_UNUSED(info_ptr)
++}
++#endif /* WRITE_APNG */
+ #endif /* WRITE */
+Index: pngpread.c
+===================================================================
+--- pngpread.c
++++ pngpread.c
+@@ -195,6 +195,89 @@
  
     chunk_name = png_ptr->chunk_name;
  
@@ -345,42 +711,29 @@ diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
 +      if (chunk_name == png_IDAT)
 +      {
 +         /* Discard trailing IDATs for the first frame */
-+         if (png_ptr->mode & PNG_HAVE_fcTL || png_ptr->num_frames_read > 1)
++         if ((png_ptr->mode & PNG_HAVE_fcTL) != 0 ||
++             png_ptr->num_frames_read > 1)
 +            png_error(png_ptr, "out of place IDAT");
 +
-+         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-+         {
-+            png_push_save_buffer(png_ptr);
-+            return;
-+         }
-+
++         PNG_PUSH_SAVE_BUFFER_IF_FULL
++         png_crc_finish(png_ptr, png_ptr->push_length);
 +         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
-+         return;
 +      }
++
 +      else if (chunk_name == png_fdAT)
 +      {
-+         if (png_ptr->buffer_size < 4)
-+         {
-+            png_push_save_buffer(png_ptr);
-+            return;
-+         }
-+
++         PNG_PUSH_SAVE_BUFFER_IF_LT(4)
 +         png_ensure_sequence_number(png_ptr, 4);
 +
-+         if (!(png_ptr->mode & PNG_HAVE_fcTL))
++         if ((png_ptr->mode & PNG_HAVE_fcTL) == 0)
 +         {
 +            /* Discard trailing fdATs for frames other than the first */
 +            if (png_ptr->num_frames_read < 2)
 +               png_error(png_ptr, "out of place fdAT");
 +
-+            if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-+            {
-+               png_push_save_buffer(png_ptr);
-+               return;
-+            }
-+
++            PNG_PUSH_SAVE_BUFFER_IF_FULL
++            png_crc_finish(png_ptr, png_ptr->push_length);
 +            png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
-+            return;
 +         }
 +
 +         else
@@ -389,25 +742,18 @@ diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
 +            png_ptr->idat_size = png_ptr->push_length - 4;
 +            png_ptr->mode |= PNG_HAVE_IDAT;
 +            png_ptr->process_mode = PNG_READ_IDAT_MODE;
-+
-+            return;
 +         }
 +      }
 +
 +      else if (chunk_name == png_fcTL)
 +      {
-+         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-+         {
-+            png_push_save_buffer(png_ptr);
-+            return;
-+         }
-+
++         PNG_PUSH_SAVE_BUFFER_IF_FULL
 +         png_read_reset(png_ptr);
 +         png_ptr->mode &= ~PNG_HAVE_fcTL;
 +
 +         png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
 +
-+         if (!(png_ptr->mode & PNG_HAVE_fcTL))
++         if ((png_ptr->mode & PNG_HAVE_fcTL) == 0)
 +            png_error(png_ptr, "missing required fcTL chunk");
 +
 +         png_read_reinit(png_ptr, info_ptr);
@@ -417,31 +763,34 @@ diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
 +            (*(png_ptr->frame_info_fn))(png_ptr, png_ptr->num_frames_read);
 +
 +         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
++      }
 +
-+         return;
++      else if (chunk_name == png_IEND)
++      {
++         PNG_PUSH_SAVE_BUFFER_IF_FULL
++         png_warning(png_ptr, "Number of actual frames fewer than expected");
++         png_crc_finish(png_ptr, png_ptr->push_length);
++         png_ptr->process_mode = PNG_READ_DONE_MODE;
++         png_push_have_end(png_ptr, info_ptr);
 +      }
 +
 +      else
 +      {
-+         if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-+         {
-+            png_push_save_buffer(png_ptr);
-+            return;
-+         }
++         PNG_PUSH_SAVE_BUFFER_IF_FULL
 +         png_warning(png_ptr, "Skipped (ignored) a chunk "
 +                              "between APNG chunks");
++         png_crc_finish(png_ptr, png_ptr->push_length);
 +         png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
-+         return;
 +      }
 +
 +      return;
 +   }
-+#endif /* PNG_READ_APNG_SUPPORTED */
++#endif /* READ_APNG */
 +
     if (chunk_name == png_IDAT)
     {
        if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
-@@ -260,6 +360,9 @@
+@@ -261,6 +344,9 @@
  
     else if (chunk_name == png_IDAT)
     {
@@ -451,38 +800,28 @@ diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
        png_ptr->idat_size = png_ptr->push_length;
        png_ptr->process_mode = PNG_READ_IDAT_MODE;
        png_push_have_info(png_ptr, info_ptr);
-@@ -405,6 +508,30 @@
-       png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+@@ -407,6 +493,20 @@
     }
  #endif
+ 
 +#ifdef PNG_READ_APNG_SUPPORTED
 +   else if (chunk_name == png_acTL)
 +   {
-+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-+      {
-+         png_push_save_buffer(png_ptr);
-+         return;
-+      }
-+
++      PNG_PUSH_SAVE_BUFFER_IF_FULL
 +      png_handle_acTL(png_ptr, info_ptr, png_ptr->push_length);
 +   }
 +
 +   else if (chunk_name == png_fcTL)
 +   {
-+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-+      {
-+         png_push_save_buffer(png_ptr);
-+         return;
-+      }
-+
++      PNG_PUSH_SAVE_BUFFER_IF_FULL
 +      png_handle_fcTL(png_ptr, info_ptr, png_ptr->push_length);
 +   }
 +
-+#endif /* PNG_READ_APNG_SUPPORTED */
- 
++#endif /* READ_APNG */
     else
     {
-@@ -538,7 +665,11 @@
+       PNG_PUSH_SAVE_BUFFER_IF_FULL
+@@ -539,7 +639,11 @@
        png_byte chunk_tag[4];
  
        /* TODO: this code can be commoned up with the same code in push_read */
@@ -494,14 +833,14 @@ diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
        png_push_fill_buffer(png_ptr, chunk_length, 4);
        png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
        png_reset_crc(png_ptr);
-@@ -546,17 +677,64 @@
+@@ -547,17 +651,60 @@
        png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag);
        png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
  
 +#ifdef PNG_READ_APNG_SUPPORTED
 +      if (png_ptr->chunk_name != png_fdAT && png_ptr->num_frames_read > 0)
 +      {
-+          if (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)
++          if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) != 0)
 +          {
 +              png_ptr->process_mode = PNG_READ_CHUNK_MODE;
 +              if (png_ptr->frame_end_fn != NULL)
@@ -513,11 +852,7 @@ diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
 +          {
 +              if (png_ptr->chunk_name == png_IEND)
 +                  png_error(png_ptr, "Not enough image data");
-+              if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-+              {
-+                 png_push_save_buffer(png_ptr);
-+                 return;
-+              }
++              PNG_PUSH_SAVE_BUFFER_IF_FULL
 +              png_warning(png_ptr, "Skipping (ignoring) a chunk between "
 +                                   "APNG chunks");
 +              png_crc_finish(png_ptr, png_ptr->push_length);
@@ -559,23 +894,24 @@ diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
     }
  
     if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
-@@ -630,6 +808,15 @@
+@@ -631,6 +778,16 @@
     if (!(buffer_length > 0) || buffer == NULL)
        png_error(png_ptr, "No IDAT data (internal error)");
  
 +#ifdef PNG_READ_APNG_SUPPORTED
 +   /* If the app is not APNG-aware, decode only the first frame */
-+   if (!(png_ptr->apng_flags & PNG_APNG_APP) && png_ptr->num_frames_read > 0)
++   if ((png_ptr->apng_flags & PNG_APNG_APP) == 0 &&
++      png_ptr->num_frames_read > 0)
 +   {
-+     png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
-+     return;
++      png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
++      return;
 +   }
 +#endif
 +
     /* This routine must process all the data it has been given
      * before returning, calling the row callback as required to
      * handle the uncompressed results.
-@@ -1084,6 +1271,18 @@
+@@ -1085,6 +1242,18 @@
     png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
  }
  
@@ -594,193 +930,174 @@ diff -Naru libpng-1.6.31.org/pngpread.c libpng-1.6.31/pngpread.c
  png_voidp PNGAPI
  png_get_progressive_ptr(png_const_structrp png_ptr)
  {
-diff -Naru libpng-1.6.31.org/pngpriv.h libpng-1.6.31/pngpriv.h
---- libpng-1.6.31.org/pngpriv.h	2017-07-29 10:08:06.210574185 +0900
-+++ libpng-1.6.31/pngpriv.h	2017-07-29 10:50:19.582316721 +0900
-@@ -628,6 +628,10 @@
- #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000U /* Have another chunk after IDAT */
-                    /*             0x4000U (unused) */
- #define PNG_IS_READ_STRUCT        0x8000U /* Else is a write struct */
+Index: pngset.c
+===================================================================
+--- pngset.c
++++ pngset.c
+@@ -288,6 +288,11 @@
+    info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
+ 
+    info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
++
 +#ifdef PNG_APNG_SUPPORTED
-+#define PNG_HAVE_acTL            0x10000U
-+#define PNG_HAVE_fcTL            0x20000U
++   /* for non-animated png. this may be overwritten from an acTL chunk later */
++   info_ptr->num_frames = 1;
 +#endif
+ }
  
- /* Flags for the transformations the PNG library does on the image data */
- #define PNG_BGR                 0x0001U
-@@ -864,6 +868,16 @@
- #define png_tRNS PNG_U32(116,  82,  78,  83)
- #define png_zTXt PNG_U32(122,  84,  88, 116)
+ #ifdef PNG_oFFs_SUPPORTED
+@@ -1158,6 +1163,146 @@
+ }
+ #endif /* sPLT */
  
 +#ifdef PNG_APNG_SUPPORTED
-+#define png_acTL PNG_U32( 97,  99,  84,  76)
-+#define png_fcTL PNG_U32(102,  99,  84,  76)
-+#define png_fdAT PNG_U32(102, 100,  65,  84)
++png_uint_32 PNGAPI
++png_set_acTL(png_structp png_ptr, png_infop info_ptr,
++    png_uint_32 num_frames, png_uint_32 num_plays)
++{
++    png_debug1(1, "in %s storage function", "acTL");
 +
-+/* For png_struct.apng_flags: */
-+#define PNG_FIRST_FRAME_HIDDEN       0x0001U
-+#define PNG_APNG_APP                 0x0002U
-+#endif
++    if (png_ptr == NULL || info_ptr == NULL)
++    {
++        png_warning(png_ptr,
++                    "Call to png_set_acTL() with NULL png_ptr "
++                    "or info_ptr ignored");
++        return (0);
++    }
++    if (num_frames == 0)
++    {
++        png_warning(png_ptr,
++                    "Ignoring attempt to set acTL with num_frames zero");
++        return (0);
++    }
++    if (num_frames > PNG_UINT_31_MAX)
++    {
++        png_warning(png_ptr,
++                    "Ignoring attempt to set acTL with num_frames > 2^31-1");
++        return (0);
++    }
++    if (num_plays > PNG_UINT_31_MAX)
++    {
++        png_warning(png_ptr,
++                    "Ignoring attempt to set acTL with num_plays > 2^31-1");
++        return (0);
++    }
 +
- /* The following will work on (signed char*) strings, whereas the get_uint_32
-  * macro will fail on top-bit-set values because of the sign extension.
-  */
-@@ -1627,6 +1641,47 @@
-     */
- #endif
- 
-+#ifdef PNG_APNG_SUPPORTED
-+PNG_INTERNAL_FUNCTION(void,png_ensure_fcTL_is_valid,(png_structp png_ptr,
-+   png_uint_32 width, png_uint_32 height,
-+   png_uint_32 x_offset, png_uint_32 y_offset,
-+   png_uint_16 delay_num, png_uint_16 delay_den,
-+   png_byte dispose_op, png_byte blend_op), PNG_EMPTY);
++    info_ptr->num_frames = num_frames;
++    info_ptr->num_plays = num_plays;
 +
-+#ifdef PNG_READ_APNG_SUPPORTED
-+PNG_INTERNAL_FUNCTION(void,png_handle_acTL,(png_structp png_ptr, png_infop info_ptr,
-+   png_uint_32 length),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_handle_fcTL,(png_structp png_ptr, png_infop info_ptr,
-+   png_uint_32 length),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_handle_fdAT,(png_structp png_ptr, png_infop info_ptr,
-+   png_uint_32 length),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_have_info,(png_structp png_ptr, png_infop info_ptr),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_ensure_sequence_number,(png_structp png_ptr,
-+   png_uint_32 length),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_read_reset,(png_structp png_ptr),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_read_reinit,(png_structp png_ptr,
-+   png_infop info_ptr),PNG_EMPTY);
-+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-+PNG_INTERNAL_FUNCTION(void,png_progressive_read_reset,(png_structp png_ptr),PNG_EMPTY);
-+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-+#endif /* PNG_READ_APNG_SUPPORTED */
++    info_ptr->valid |= PNG_INFO_acTL;
 +
-+#ifdef PNG_WRITE_APNG_SUPPORTED
-+PNG_INTERNAL_FUNCTION(void,png_write_acTL,(png_structp png_ptr,
-+   png_uint_32 num_frames, png_uint_32 num_plays),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_write_fcTL,(png_structp png_ptr,
-+   png_uint_32 width, png_uint_32 height,
-+   png_uint_32 x_offset, png_uint_32 y_offset,
-+   png_uint_16 delay_num, png_uint_16 delay_den,
-+   png_byte dispose_op, png_byte blend_op),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_write_fdAT,(png_structp png_ptr,
-+   png_const_bytep data, png_size_t length),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_write_reset,(png_structp png_ptr),PNG_EMPTY);
-+PNG_INTERNAL_FUNCTION(void,png_write_reinit,(png_structp png_ptr,
-+   png_infop info_ptr, png_uint_32 width, png_uint_32 height),PNG_EMPTY);
-+#endif /* PNG_WRITE_APNG_SUPPORTED */
-+#endif /* PNG_APNG_SUPPORTED */
-+
- /* Added at libpng version 1.4.0 */
- #ifdef PNG_COLORSPACE_SUPPORTED
- /* These internal functions are for maintaining the colorspace structure within
-diff -Naru libpng-1.6.31.org/pngread.c libpng-1.6.31/pngread.c
---- libpng-1.6.31.org/pngread.c	2017-07-29 10:08:06.211574269 +0900
-+++ libpng-1.6.31/pngread.c	2017-07-29 10:50:19.582316721 +0900
-@@ -161,6 +161,9 @@
- 
-       else if (chunk_name == png_IDAT)
-       {
-+#ifdef PNG_READ_APNG_SUPPORTED
-+         png_have_info(png_ptr, info_ptr);
-+#endif
-          png_ptr->idat_size = length;
-          break;
-       }
-@@ -250,6 +253,17 @@
-          png_handle_iTXt(png_ptr, info_ptr, length);
- #endif
- 
-+#ifdef PNG_READ_APNG_SUPPORTED
-+      else if (chunk_name == png_acTL)
-+         png_handle_acTL(png_ptr, info_ptr, length);
++    return (1);
++}
 +
-+      else if (chunk_name == png_fcTL)
-+         png_handle_fcTL(png_ptr, info_ptr, length);
++/* delay_num and delay_den can hold any 16-bit values including zero */
++png_uint_32 PNGAPI
++png_set_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr,
++    png_uint_32 width, png_uint_32 height,
++    png_uint_32 x_offset, png_uint_32 y_offset,
++    png_uint_16 delay_num, png_uint_16 delay_den,
++    png_byte dispose_op, png_byte blend_op)
++{
++    png_debug1(1, "in %s storage function", "fcTL");
 +
-+      else if (chunk_name == png_fdAT)
-+         png_handle_fdAT(png_ptr, info_ptr, length);
-+#endif
++    if (png_ptr == NULL || info_ptr == NULL)
++    {
++        png_warning(png_ptr,
++                    "Call to png_set_fcTL() with NULL png_ptr or info_ptr "
++                    "ignored");
++        return (0);
++    }
 +
-       else
-          png_handle_unknown(png_ptr, info_ptr, length,
-              PNG_HANDLE_CHUNK_AS_DEFAULT);
-@@ -257,6 +271,72 @@
- }
- #endif /* SEQUENTIAL_READ */
- 
-+#ifdef PNG_READ_APNG_SUPPORTED
-+void PNGAPI
-+png_read_frame_head(png_structp png_ptr, png_infop info_ptr)
-+{
-+    png_byte have_chunk_after_DAT; /* after IDAT or after fdAT */
++    png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset,
++                             delay_num, delay_den, dispose_op, blend_op);
 +
-+    png_debug(0, "Reading frame head");
++    if (blend_op == PNG_BLEND_OP_OVER)
++    {
++        if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0 &&
++            png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) == 0)
++        {
++          png_warning(png_ptr, "PNG_BLEND_OP_OVER is meaningless "
++                               "and wasteful for opaque images, ignored");
++          blend_op = PNG_BLEND_OP_SOURCE;
++        }
++    }
 +
-+    if (!(png_ptr->mode & PNG_HAVE_acTL))
-+        png_error(png_ptr, "attempt to png_read_frame_head() but "
-+                           "no acTL present");
++    info_ptr->next_frame_width = width;
++    info_ptr->next_frame_height = height;
++    info_ptr->next_frame_x_offset = x_offset;
++    info_ptr->next_frame_y_offset = y_offset;
++    info_ptr->next_frame_delay_num = delay_num;
++    info_ptr->next_frame_delay_den = delay_den;
++    info_ptr->next_frame_dispose_op = dispose_op;
++    info_ptr->next_frame_blend_op = blend_op;
 +
-+    /* do nothing for the main IDAT */
-+    if (png_ptr->num_frames_read == 0)
-+        return;
++    info_ptr->valid |= PNG_INFO_fcTL;
 +
-+    png_read_reset(png_ptr);
-+    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-+    png_ptr->mode &= ~PNG_HAVE_fcTL;
++    return (1);
++}
 +
-+    have_chunk_after_DAT = 0;
-+    for (;;)
-+    {
-+        png_uint_32 length = png_read_chunk_header(png_ptr);
++void /* PRIVATE */
++png_ensure_fcTL_is_valid(png_structp png_ptr,
++    png_uint_32 width, png_uint_32 height,
++    png_uint_32 x_offset, png_uint_32 y_offset,
++    png_uint_16 delay_num, png_uint_16 delay_den,
++    png_byte dispose_op, png_byte blend_op)
++{
++    if (width == 0 || width > PNG_UINT_31_MAX)
++        png_error(png_ptr, "invalid width in fcTL (0 or > 2^31-1)");
++    if (height == 0 || height > PNG_UINT_31_MAX)
++        png_error(png_ptr, "invalid height in fcTL (0 or > 2^31-1)");
++    if (x_offset > PNG_UINT_31_MAX)
++        png_error(png_ptr, "invalid x_offset in fcTL (> 2^31-1)");
++    if (y_offset > PNG_UINT_31_MAX)
++        png_error(png_ptr, "invalid y_offset in fcTL (> 2^31-1)");
++    if (width + x_offset > png_ptr->first_frame_width ||
++        height + y_offset > png_ptr->first_frame_height)
++        png_error(png_ptr, "dimensions of a frame are greater than "
++                           "the ones in IHDR");
 +
-+        if (png_ptr->chunk_name == png_IDAT)
-+        {
-+            /* discard trailing IDATs for the first frame */
-+            if (have_chunk_after_DAT || png_ptr->num_frames_read > 1)
-+                png_error(png_ptr, "png_read_frame_head(): out of place IDAT");
-+            png_crc_finish(png_ptr, length);
-+        }
++    if (dispose_op != PNG_DISPOSE_OP_NONE &&
++        dispose_op != PNG_DISPOSE_OP_BACKGROUND &&
++        dispose_op != PNG_DISPOSE_OP_PREVIOUS)
++        png_error(png_ptr, "invalid dispose_op in fcTL");
 +
-+        else if (png_ptr->chunk_name == png_fcTL)
-+        {
-+            png_handle_fcTL(png_ptr, info_ptr, length);
-+            have_chunk_after_DAT = 1;
-+        }
++    if (blend_op != PNG_BLEND_OP_SOURCE &&
++        blend_op != PNG_BLEND_OP_OVER)
++        png_error(png_ptr, "invalid blend_op in fcTL");
 +
-+        else if (png_ptr->chunk_name == png_fdAT)
-+        {
-+            png_ensure_sequence_number(png_ptr, length);
++    PNG_UNUSED(delay_num)
++    PNG_UNUSED(delay_den)
++}
 +
-+            /* discard trailing fdATs for frames other than the first */
-+            if (!have_chunk_after_DAT && png_ptr->num_frames_read > 1)
-+                png_crc_finish(png_ptr, length - 4);
-+            else if(png_ptr->mode & PNG_HAVE_fcTL)
-+            {
-+                png_ptr->idat_size = length - 4;
-+                png_ptr->mode |= PNG_HAVE_IDAT;
++png_uint_32 PNGAPI
++png_set_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr,
++                              png_byte is_hidden)
++{
++    png_debug(1, "in png_first_frame_is_hidden()");
 +
-+                break;
-+            }
-+            else
-+                png_error(png_ptr, "png_read_frame_head(): out of place fdAT");
-+        }
-+        else
-+        {
-+            png_warning(png_ptr, "Skipped (ignored) a chunk "
-+                                 "between APNG chunks");
-+            png_crc_finish(png_ptr, length);
-+        }
-+    }
++    if (png_ptr == NULL)
++        return 0;
++
++    if (is_hidden != 0)
++        png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
++    else
++        png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN;
++
++    PNG_UNUSED(info_ptr)
++
++    return 1;
 +}
-+#endif /* PNG_READ_APNG_SUPPORTED */
++#endif /* APNG */
 +
- /* Optional call to update the users info_ptr structure */
- void PNGAPI
- png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
-diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
---- libpng-1.6.31.org/pngrutil.c	2017-07-29 10:08:06.212574354 +0900
-+++ libpng-1.6.31/pngrutil.c	2017-07-29 10:50:19.583316806 +0900
-@@ -861,6 +861,11 @@
+ #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+ static png_byte
+ check_location(png_const_structrp png_ptr, int location)
+Index: pngrutil.c
+===================================================================
+--- pngrutil.c
++++ pngrutil.c
+@@ -864,6 +864,11 @@
     filter_type = buf[11];
     interlace_type = buf[12];
  
@@ -792,7 +1109,7 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
     /* Set internal variables */
     png_ptr->width = width;
     png_ptr->height = height;
-@@ -2802,6 +2807,179 @@
+@@ -2847,6 +2852,180 @@
  }
  #endif
  
@@ -807,17 +1124,17 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +
 +    png_debug(1, "in png_handle_acTL");
 +
-+    if (!(png_ptr->mode & PNG_HAVE_IHDR))
++    if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
 +    {
 +        png_error(png_ptr, "Missing IHDR before acTL");
 +    }
-+    else if (png_ptr->mode & PNG_HAVE_IDAT)
++    else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
 +    {
 +        png_warning(png_ptr, "Invalid acTL after IDAT skipped");
 +        png_crc_finish(png_ptr, length);
 +        return;
 +    }
-+    else if (png_ptr->mode & PNG_HAVE_acTL)
++    else if ((png_ptr->mode & PNG_HAVE_acTL) != 0)
 +    {
 +        png_warning(png_ptr, "Duplicate acTL skipped");
 +        png_crc_finish(png_ptr, length);
@@ -838,7 +1155,7 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +
 +    /* the set function will do error checking on num_frames */
 +    didSet = png_set_acTL(png_ptr, info_ptr, num_frames, num_plays);
-+    if(didSet)
++    if (didSet != 0)
 +        png_ptr->mode |= PNG_HAVE_acTL;
 +}
 +
@@ -859,11 +1176,11 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +
 +    png_ensure_sequence_number(png_ptr, length);
 +
-+    if (!(png_ptr->mode & PNG_HAVE_IHDR))
++    if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
 +    {
 +        png_error(png_ptr, "Missing IHDR before fcTL");
 +    }
-+    else if (png_ptr->mode & PNG_HAVE_IDAT)
++    else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
 +    {
 +        /* for any frames other then the first this message may be misleading,
 +        * but correct. PNG_HAVE_IDAT is unset before the frame head is read
@@ -872,7 +1189,7 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +        png_crc_finish(png_ptr, length-4);
 +        return;
 +    }
-+    else if (png_ptr->mode & PNG_HAVE_fcTL)
++    else if ((png_ptr->mode & PNG_HAVE_fcTL) != 0)
 +    {
 +        png_warning(png_ptr, "Duplicate fcTL within one frame skipped");
 +        png_crc_finish(png_ptr, length-4);
@@ -927,7 +1244,8 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +void /* PRIVATE */
 +png_have_info(png_structp png_ptr, png_infop info_ptr)
 +{
-+    if((info_ptr->valid & PNG_INFO_acTL) && !(info_ptr->valid & PNG_INFO_fcTL))
++    if ((info_ptr->valid & PNG_INFO_acTL) != 0 &&
++        (info_ptr->valid & PNG_INFO_fcTL) == 0)
 +    {
 +        png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
 +        info_ptr->num_frames++;
@@ -967,15 +1285,27 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +
 +    png_ptr->next_seq_num++;
 +}
-+#endif /* PNG_READ_APNG_SUPPORTED */
++#endif /* READ_APNG */
 +
  #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
  /* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
  static int
-@@ -4069,7 +4247,38 @@
-       {
+@@ -3144,7 +3323,11 @@
+ {
+    png_alloc_size_t limit = PNG_UINT_31_MAX;
+ 
++#ifdef PNG_READ_APNG_SUPPORTED
++   if (png_ptr->chunk_name != png_IDAT && png_ptr->chunk_name != png_fdAT)
++#else
+    if (png_ptr->chunk_name != png_IDAT)
++#endif
+    {
+ # ifdef PNG_SET_USER_LIMITS_SUPPORTED
+       if (png_ptr->user_chunk_malloc_max > 0 &&
+@@ -4153,6 +4336,38 @@
           uInt avail_in;
           png_bytep buffer;
+ 
 +#ifdef PNG_READ_APNG_SUPPORTED
 +         png_uint_32 bytes_to_skip = 0;
 +
@@ -1001,7 +1331,7 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +                  bytes_to_skip = png_ptr->idat_size;
 +                  continue;
 +               }
- 
++
 +               png_ensure_sequence_number(png_ptr, png_ptr->idat_size);
 +
 +               png_ptr->idat_size -= 4;
@@ -1011,16 +1341,15 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
           while (png_ptr->idat_size == 0)
           {
              png_crc_finish(png_ptr, 0);
-@@ -4081,7 +4290,7 @@
+@@ -4164,6 +4379,7 @@
              if (png_ptr->chunk_name != png_IDAT)
                 png_error(png_ptr, "Not enough image data");
           }
--
-+#endif /* PNG_READ_APNG_SUPPORTED */
++#endif /* READ_APNG */
+ 
           avail_in = png_ptr->IDAT_read_size;
  
-          if (avail_in > png_ptr->idat_size)
-@@ -4144,6 +4353,9 @@
+@@ -4227,6 +4443,9 @@
  
           png_ptr->mode |= PNG_AFTER_IDAT;
           png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
@@ -1030,7 +1359,7 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
  
           if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
              png_chunk_benign_error(png_ptr, "Extra compressed data");
-@@ -4582,4 +4794,80 @@
+@@ -4665,4 +4884,80 @@
  
     png_ptr->flags |= PNG_FLAG_ROW_INIT;
  }
@@ -1056,7 +1385,7 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +    png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width);
 +    png_ptr->info_rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth,
 +        png_ptr->width);
-+    if (png_ptr->prev_row)
++    if (png_ptr->prev_row != NULL)
 +        memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
 +}
 +
@@ -1066,23 +1395,23 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +png_progressive_read_reset(png_structp png_ptr)
 +{
 +#ifdef PNG_READ_INTERLACING_SUPPORTED
-+   /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
++    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 +
-+   /* Start of interlace block */
-+    const int png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
++    /* Start of interlace block */
++    static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
 +
 +    /* Offset to next interlace block */
-+    const int png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
++    static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
 +
 +    /* Start of interlace block in the y direction */
-+    const int png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
++    static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
 +
 +    /* Offset to next interlace block in the y direction */
-+    const int png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
++    static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
 +
-+    if (png_ptr->interlaced)
++    if (png_ptr->interlaced != 0)
 +    {
-+        if (!(png_ptr->transformations & PNG_INTERLACE))
++        if ((png_ptr->transformations & PNG_INTERLACE) == 0)
 +            png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
 +                                png_pass_ystart[0]) / png_pass_yinc[0];
 +        else
@@ -1094,7 +1423,7 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +                           png_pass_inc[png_ptr->pass];
 +    }
 +    else
-+#endif /* PNG_READ_INTERLACING_SUPPORTED */
++#endif /* READ_INTERLACING */
 +    {
 +        png_ptr->num_rows = png_ptr->height;
 +        png_ptr->iwidth = png_ptr->width;
@@ -1108,424 +1437,13 @@ diff -Naru libpng-1.6.31.org/pngrutil.c libpng-1.6.31/pngrutil.c
 +    png_ptr->zstream.avail_out = (uInt)PNG_ROWBYTES(png_ptr->pixel_depth,
 +        png_ptr->iwidth) + 1;
 +}
-+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
-+#endif /* PNG_READ_APNG_SUPPORTED */
++#endif /* PROGRESSIVE_READ */
++#endif /* READ_APNG */
  #endif /* READ */
-diff -Naru libpng-1.6.31.org/pngset.c libpng-1.6.31/pngset.c
---- libpng-1.6.31.org/pngset.c	2017-07-29 10:08:06.212574354 +0900
-+++ libpng-1.6.31/pngset.c	2017-07-29 10:50:19.587317145 +0900
-@@ -274,6 +274,11 @@
-    info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
- 
-    info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
-+
-+#ifdef PNG_APNG_SUPPORTED
-+   /* for non-animated png. this may be overwritten from an acTL chunk later */
-+   info_ptr->num_frames = 1;
-+#endif
- }
- 
- #ifdef PNG_oFFs_SUPPORTED
-@@ -1144,6 +1149,147 @@
- }
- #endif /* sPLT */
- 
-+#ifdef PNG_APNG_SUPPORTED
-+png_uint_32 PNGAPI
-+png_set_acTL(png_structp png_ptr, png_infop info_ptr,
-+    png_uint_32 num_frames, png_uint_32 num_plays)
-+{
-+    png_debug1(1, "in %s storage function", "acTL");
-+
-+    if (png_ptr == NULL || info_ptr == NULL)
-+    {
-+        png_warning(png_ptr,
-+                    "Call to png_set_acTL() with NULL png_ptr "
-+                    "or info_ptr ignored");
-+        return (0);
-+    }
-+    if (num_frames == 0)
-+    {
-+        png_warning(png_ptr,
-+                    "Ignoring attempt to set acTL with num_frames zero");
-+        return (0);
-+    }
-+    if (num_frames > PNG_UINT_31_MAX)
-+    {
-+        png_warning(png_ptr,
-+                    "Ignoring attempt to set acTL with num_frames > 2^31-1");
-+        return (0);
-+    }
-+    if (num_plays > PNG_UINT_31_MAX)
-+    {
-+        png_warning(png_ptr,
-+                    "Ignoring attempt to set acTL with num_plays "
-+                    "> 2^31-1");
-+        return (0);
-+    }
-+
-+    info_ptr->num_frames = num_frames;
-+    info_ptr->num_plays = num_plays;
-+
-+    info_ptr->valid |= PNG_INFO_acTL;
-+
-+    return (1);
-+}
-+
-+/* delay_num and delay_den can hold any 16-bit values including zero */
-+png_uint_32 PNGAPI
-+png_set_next_frame_fcTL(png_structp png_ptr, png_infop info_ptr,
-+    png_uint_32 width, png_uint_32 height,
-+    png_uint_32 x_offset, png_uint_32 y_offset,
-+    png_uint_16 delay_num, png_uint_16 delay_den,
-+    png_byte dispose_op, png_byte blend_op)
-+{
-+    png_debug1(1, "in %s storage function", "fcTL");
-+
-+    if (png_ptr == NULL || info_ptr == NULL)
-+    {
-+        png_warning(png_ptr,
-+                    "Call to png_set_fcTL() with NULL png_ptr or info_ptr "
-+                    "ignored");
-+        return (0);
-+    }
-+
-+    png_ensure_fcTL_is_valid(png_ptr, width, height, x_offset, y_offset,
-+                             delay_num, delay_den, dispose_op, blend_op);
-+
-+    if (blend_op == PNG_BLEND_OP_OVER)
-+    {
-+        if (!(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) &&
-+            !(png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
-+        {
-+          png_warning(png_ptr, "PNG_BLEND_OP_OVER is meaningless "
-+                               "and wasteful for opaque images, ignored");
-+          blend_op = PNG_BLEND_OP_SOURCE;
-+        }
-+    }
-+
-+    info_ptr->next_frame_width = width;
-+    info_ptr->next_frame_height = height;
-+    info_ptr->next_frame_x_offset = x_offset;
-+    info_ptr->next_frame_y_offset = y_offset;
-+    info_ptr->next_frame_delay_num = delay_num;
-+    info_ptr->next_frame_delay_den = delay_den;
-+    info_ptr->next_frame_dispose_op = dispose_op;
-+    info_ptr->next_frame_blend_op = blend_op;
-+
-+    info_ptr->valid |= PNG_INFO_fcTL;
-+
-+    return (1);
-+}
-+
-+void /* PRIVATE */
-+png_ensure_fcTL_is_valid(png_structp png_ptr,
-+    png_uint_32 width, png_uint_32 height,
-+    png_uint_32 x_offset, png_uint_32 y_offset,
-+    png_uint_16 delay_num, png_uint_16 delay_den,
-+    png_byte dispose_op, png_byte blend_op)
-+{
-+    if (width == 0 || width > PNG_UINT_31_MAX)
-+        png_error(png_ptr, "invalid width in fcTL (> 2^31-1)");
-+    if (height == 0 || height > PNG_UINT_31_MAX)
-+        png_error(png_ptr, "invalid height in fcTL (> 2^31-1)");
-+    if (x_offset > PNG_UINT_31_MAX)
-+        png_error(png_ptr, "invalid x_offset in fcTL (> 2^31-1)");
-+    if (y_offset > PNG_UINT_31_MAX)
-+        png_error(png_ptr, "invalid y_offset in fcTL (> 2^31-1)");
-+    if (width + x_offset > png_ptr->first_frame_width ||
-+        height + y_offset > png_ptr->first_frame_height)
-+        png_error(png_ptr, "dimensions of a frame are greater than"
-+                           "the ones in IHDR");
-+
-+    if (dispose_op != PNG_DISPOSE_OP_NONE &&
-+        dispose_op != PNG_DISPOSE_OP_BACKGROUND &&
-+        dispose_op != PNG_DISPOSE_OP_PREVIOUS)
-+        png_error(png_ptr, "invalid dispose_op in fcTL");
-+
-+    if (blend_op != PNG_BLEND_OP_SOURCE &&
-+        blend_op != PNG_BLEND_OP_OVER)
-+        png_error(png_ptr, "invalid blend_op in fcTL");
-+
-+    PNG_UNUSED(delay_num)
-+    PNG_UNUSED(delay_den)
-+}
-+
-+png_uint_32 PNGAPI
-+png_set_first_frame_is_hidden(png_structp png_ptr, png_infop info_ptr,
-+                              png_byte is_hidden)
-+{
-+    png_debug(1, "in png_first_frame_is_hidden()");
-+
-+    if (png_ptr == NULL)
-+        return 0;
-+
-+    if (is_hidden)
-+        png_ptr->apng_flags |= PNG_FIRST_FRAME_HIDDEN;
-+    else
-+        png_ptr->apng_flags &= ~PNG_FIRST_FRAME_HIDDEN;
-+
-+    PNG_UNUSED(info_ptr)
-+
-+    return 1;
-+}
-+#endif /* PNG_APNG_SUPPORTED */
-+
- #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
- static png_byte
- check_location(png_const_structrp png_ptr, int location)
-diff -Naru libpng-1.6.31.org/pngstruct.h libpng-1.6.31/pngstruct.h
---- libpng-1.6.31.org/pngstruct.h	2017-07-29 10:08:06.212574354 +0900
-+++ libpng-1.6.31/pngstruct.h	2017-07-29 10:50:19.583316806 +0900
-@@ -403,6 +403,27 @@
-    png_byte filter_type;
- #endif
- 
-+#ifdef PNG_APNG_SUPPORTED
-+   png_uint_32 apng_flags;
-+   png_uint_32 next_seq_num;         /* next fcTL/fdAT chunk sequence number */
-+   png_uint_32 first_frame_width;
-+   png_uint_32 first_frame_height;
-+
-+#ifdef PNG_READ_APNG_SUPPORTED
-+   png_uint_32 num_frames_read;      /* incremented after all image data of */
-+                                     /* a frame is read */
-+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
-+   png_progressive_frame_ptr frame_info_fn; /* frame info read callback */
-+   png_progressive_frame_ptr frame_end_fn;  /* frame data read callback */
-+#endif
-+#endif
-+
-+#ifdef PNG_WRITE_APNG_SUPPORTED
-+   png_uint_32 num_frames_to_write;
-+   png_uint_32 num_frames_written;
-+#endif
-+#endif /* PNG_APNG_SUPPORTED */
-+
- /* New members added in libpng-1.2.0 */
- 
- /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
-diff -Naru libpng-1.6.31.org/pngtest.c libpng-1.6.31/pngtest.c
---- libpng-1.6.31.org/pngtest.c	2017-07-29 10:08:06.212574354 +0900
-+++ libpng-1.6.31/pngtest.c	2017-07-29 10:50:19.583316806 +0900
-@@ -874,6 +874,10 @@
-    volatile int num_passes;
-    int pass;
-    int bit_depth, color_type;
-+#ifdef PNG_APNG_SUPPORTED
-+   png_uint_32 num_frames;
-+   png_uint_32 num_plays;
-+#endif
- 
-    row_buf = NULL;
-    error_parameters.file_name = inname;
-@@ -1366,6 +1370,22 @@
-       }
-    }
- #endif
-+
-+#ifdef PNG_APNG_SUPPORTED
-+   if (png_get_valid(read_ptr, read_info_ptr, PNG_INFO_acTL))
-+   {
-+      if (png_get_acTL(read_ptr, read_info_ptr, &num_frames, &num_plays))
-+      {
-+         png_byte is_hidden;
-+         pngtest_debug2("Handling acTL chunks (frames %ld, plays %ld)",
-+                    num_frames, num_plays);
-+         png_set_acTL(write_ptr, write_info_ptr, num_frames, num_plays);
-+         is_hidden = png_get_first_frame_is_hidden(read_ptr, read_info_ptr);
-+         png_set_first_frame_is_hidden(write_ptr, write_info_ptr, is_hidden);
-+      }
-+   }
-+#endif
-+
- #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-    {
-       png_unknown_chunkp unknowns;
-@@ -1442,6 +1462,110 @@
-    t_misc += (t_stop - t_start);
-    t_start = t_stop;
- #endif
-+#ifdef PNG_APNG_SUPPORTED
-+   if (png_get_valid(read_ptr, read_info_ptr, PNG_INFO_acTL))
-+   {
-+      png_uint_32 frame;
-+      for (frame = 0; frame < num_frames; frame++)
-+      {
-+         png_uint_32 frame_width;
-+         png_uint_32 frame_height;
-+         png_uint_32 x_offset;
-+         png_uint_32 y_offset;
-+         png_uint_16 delay_num;
-+         png_uint_16 delay_den;
-+         png_byte dispose_op;
-+         png_byte blend_op;
-+         png_read_frame_head(read_ptr, read_info_ptr);
-+         if (png_get_valid(read_ptr, read_info_ptr, PNG_INFO_fcTL))
-+         {
-+            png_get_next_frame_fcTL(read_ptr, read_info_ptr,
-+                                    &frame_width, &frame_height,
-+                                    &x_offset, &y_offset,
-+                                    &delay_num, &delay_den,
-+                                    &dispose_op, &blend_op);
-+         }
-+         else
-+         {
-+            frame_width = width;
-+            frame_height = height;
-+            x_offset = 0;
-+            y_offset = 0;
-+            delay_num = 1;
-+            delay_den = 1;
-+            dispose_op = PNG_DISPOSE_OP_NONE;
-+            blend_op = PNG_BLEND_OP_SOURCE;
-+         }
-+#ifdef PNG_WRITE_APNG_SUPPORTED
-+         png_write_frame_head(write_ptr, write_info_ptr, (png_bytepp)&row_buf,
-+                              frame_width, frame_height,
-+                              x_offset, y_offset,
-+                              delay_num, delay_den,
-+                              dispose_op, blend_op);
-+#endif
-+         for (pass = 0; pass < num_passes; pass++)
-+         {
-+#           ifdef calc_pass_height
-+               png_uint_32 pass_height;
-+
-+               if (num_passes == 7) /* interlaced */
-+               {
-+                  if (PNG_PASS_COLS(frame_width, pass) > 0)
-+                     pass_height = PNG_PASS_ROWS(frame_height, pass);
-+
-+                  else
-+                     pass_height = 0;
-+               }
-+
-+               else /* not interlaced */
-+                  pass_height = frame_height;
-+#           else
-+#              define pass_height frame_height
-+#           endif
-+
-+            pngtest_debug1("Writing row data for pass %d", pass);
-+            for (y = 0; y < pass_height; y++)
-+            {
-+#ifndef SINGLE_ROWBUF_ALLOC
-+               pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y);
-+
-+               row_buf = (png_bytep)png_malloc(read_ptr,
-+                  png_get_rowbytes(read_ptr, read_info_ptr));
-+
-+               pngtest_debug2("\t0x%08lx (%lu bytes)", (unsigned long)row_buf,
-+                  (unsigned long)png_get_rowbytes(read_ptr, read_info_ptr));
-+
-+#endif /* !SINGLE_ROWBUF_ALLOC */
-+               png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1);
-+
-+#ifdef PNG_WRITE_SUPPORTED
-+#ifdef PNGTEST_TIMING
-+               t_stop = (float)clock();
-+               t_decode += (t_stop - t_start);
-+               t_start = t_stop;
-+#endif
-+               png_write_rows(write_ptr, (png_bytepp)&row_buf, 1);
-+#ifdef PNGTEST_TIMING
-+               t_stop = (float)clock();
-+               t_encode += (t_stop - t_start);
-+               t_start = t_stop;
-+#endif
-+#endif /* PNG_WRITE_SUPPORTED */
-+
-+#ifndef SINGLE_ROWBUF_ALLOC
-+               pngtest_debug2("Freeing row buffer (pass %d, y = %u)", pass, y);
-+               png_free(read_ptr, row_buf);
-+               row_buf = NULL;
-+#endif /* !SINGLE_ROWBUF_ALLOC */
-+            }
-+         }
-+#ifdef PNG_WRITE_APNG_SUPPORTED
-+         png_write_frame_tail(write_ptr, write_info_ptr);
-+#endif
-+      }
-+   }
-+   else
-+#endif
-    for (pass = 0; pass < num_passes; pass++)
-    {
- #     ifdef calc_pass_height
-diff -Naru libpng-1.6.31.org/pngwrite.c libpng-1.6.31/pngwrite.c
---- libpng-1.6.31.org/pngwrite.c	2017-07-29 10:08:06.213574438 +0900
-+++ libpng-1.6.31/pngwrite.c	2017-07-29 10:50:19.584316891 +0900
-@@ -128,6 +128,10 @@
-        * the application continues writing the PNG.  So check the 'invalid'
-        * flag here too.
-        */
-+#ifdef PNG_WRITE_APNG_SUPPORTED
-+      if (info_ptr->valid & PNG_INFO_acTL)
-+         png_write_acTL(png_ptr, info_ptr->num_frames, info_ptr->num_plays);
-+#endif
- #ifdef PNG_GAMMA_SUPPORTED
- #  ifdef PNG_WRITE_gAMA_SUPPORTED
-       if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
-@@ -365,6 +369,11 @@
-       png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
- #endif
- 
-+#ifdef PNG_WRITE_APNG_SUPPORTED
-+   if (png_ptr->num_frames_written != png_ptr->num_frames_to_write)
-+      png_error(png_ptr, "Not enough frames written");
-+#endif
-+
-    /* See if user wants us to write information chunks */
-    if (info_ptr != NULL)
-    {
-@@ -1450,6 +1459,43 @@
- }
- #endif
- 
-+#ifdef PNG_WRITE_APNG_SUPPORTED
-+void PNGAPI
-+png_write_frame_head(png_structp png_ptr, png_infop info_ptr,
-+    png_bytepp row_pointers, png_uint_32 width, png_uint_32 height,
-+    png_uint_32 x_offset, png_uint_32 y_offset,
-+    png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
-+    png_byte blend_op)
-+{
-+    png_debug(1, "in png_write_frame_head");
-+
-+    /* there is a chance this has been set after png_write_info was called,
-+    * so it would be set but not written. is there a way to be sure? */
-+    if (!(info_ptr->valid & PNG_INFO_acTL))
-+        png_error(png_ptr, "png_write_frame_head(): acTL not set");
-+
-+    png_write_reset(png_ptr);
-+
-+    png_write_reinit(png_ptr, info_ptr, width, height);
-+
-+    if ( !(png_ptr->num_frames_written == 0 &&
-+           (png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) ) )
-+        png_write_fcTL(png_ptr, width, height, x_offset, y_offset,
-+                       delay_num, delay_den, dispose_op, blend_op);
-+
-+    PNG_UNUSED(row_pointers)
-+}
-+
-+void PNGAPI
-+png_write_frame_tail(png_structp png_ptr, png_infop info_ptr)
-+{
-+    png_debug(1, "in png_write_frame_tail");
-+
-+    png_ptr->num_frames_written++;
-+
-+    PNG_UNUSED(info_ptr)
-+}
-+#endif /* PNG_WRITE_APNG_SUPPORTED */
- 
- #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
- /* Initialize the write structure - general purpose utility. */
-diff -Naru libpng-1.6.31.org/pngwutil.c libpng-1.6.31/pngwutil.c
---- libpng-1.6.31.org/pngwutil.c	2017-07-29 10:08:06.213574438 +0900
-+++ libpng-1.6.31/pngwutil.c	2017-07-29 10:50:19.597317991 +0900
+Index: pngwutil.c
+===================================================================
+--- pngwutil.c
++++ pngwutil.c
 @@ -822,6 +822,11 @@
     /* Write the chunk */
     png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
@@ -1538,27 +1456,25 @@ diff -Naru libpng-1.6.31.org/pngwutil.c libpng-1.6.31/pngwutil.c
     if ((png_ptr->do_filter) == PNG_NO_FILTERS)
     {
        if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
-@@ -1003,8 +1008,17 @@
-                optimize_cmf(data, png_image_size(png_ptr));
+@@ -1004,7 +1009,17 @@
  #endif
  
--         if (size > 0)
--            png_write_complete_chunk(png_ptr, png_IDAT, data, size);
-+            if (size > 0)
+          if (size > 0)
 +#ifdef PNG_WRITE_APNG_SUPPORTED
-+            {
-+               if (png_ptr->num_frames_written == 0)
++         {
++            if (png_ptr->num_frames_written == 0)
 +#endif
-+               png_write_complete_chunk(png_ptr, png_IDAT, data, size);
+             png_write_complete_chunk(png_ptr, png_IDAT, data, size);
 +#ifdef PNG_WRITE_APNG_SUPPORTED
-+               else
-+                  png_write_fdAT(png_ptr, data, size);
-+            }
-+#endif /* PNG_WRITE_APNG_SUPPORTED */
++            else
++               png_write_fdAT(png_ptr, data, size);
++         }
++#endif /* WRITE_APNG */
++
           png_ptr->mode |= PNG_HAVE_IDAT;
  
           png_ptr->zstream.next_out = data;
-@@ -1051,7 +1065,17 @@
+@@ -1051,7 +1066,17 @@
  #endif
  
           if (size > 0)
@@ -1571,12 +1487,12 @@ diff -Naru libpng-1.6.31.org/pngwutil.c libpng-1.6.31/pngwutil.c
 +            else
 +               png_write_fdAT(png_ptr, data, size);
 +         }
-+#endif /* PNG_WRITE_APNG_SUPPORTED */
++#endif /* WRITE_APNG */
 +
           png_ptr->zstream.avail_out = 0;
           png_ptr->zstream.next_out = NULL;
           png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
-@@ -1896,6 +1920,82 @@
+@@ -1887,6 +1912,82 @@
  }
  #endif
  
@@ -1591,7 +1507,7 @@ diff -Naru libpng-1.6.31.org/pngwutil.c libpng-1.6.31/pngwutil.c
 +
 +    png_ptr->num_frames_to_write = num_frames;
 +
-+    if (png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN)
++    if ((png_ptr->apng_flags & PNG_FIRST_FRAME_HIDDEN) != 0)
 +        num_frames--;
 +
 +    png_save_uint_32(buf, num_frames);
@@ -1654,12 +1570,12 @@ diff -Naru libpng-1.6.31.org/pngwutil.c libpng-1.6.31/pngwutil.c
 +
 +    png_ptr->next_seq_num++;
 +}
-+#endif /* PNG_WRITE_APNG_SUPPORTED */
++#endif /* WRITE_APNG */
 +
  /* Initializes the row writing capability of libpng */
  void /* PRIVATE */
  png_write_start_row(png_structrp png_ptr)
-@@ -2790,4 +2890,39 @@
+@@ -2781,4 +2882,39 @@
     }
  #endif /* WRITE_FLUSH */
  }
@@ -1684,7 +1600,7 @@ diff -Naru libpng-1.6.31.org/pngwutil.c libpng-1.6.31/pngwutil.c
 +                           "don't match the ones in IHDR");
 +    if (width > png_ptr->first_frame_width ||
 +        height > png_ptr->first_frame_height)
-+        png_error(png_ptr, "width and/or height for a frame greater than"
++        png_error(png_ptr, "width and/or height for a frame greater than "
 +                           "the ones in IHDR");
 +
 +    png_set_IHDR(png_ptr, info_ptr, width, height,
@@ -1697,32 +1613,33 @@ diff -Naru libpng-1.6.31.org/pngwutil.c libpng-1.6.31/pngwutil.c
 +    png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
 +    png_ptr->usr_width = png_ptr->width;
 +}
-+#endif /* PNG_WRITE_APNG_SUPPORTED */
++#endif /* WRITE_APNG */
  #endif /* WRITE */
-diff -Naru libpng-1.6.31.org/scripts/symbols.def libpng-1.6.31/scripts/symbols.def
---- libpng-1.6.31.org/scripts/symbols.def	2017-07-29 10:08:06.215574607 +0900
-+++ libpng-1.6.31/scripts/symbols.def	2017-07-29 10:50:19.584316891 +0900
-@@ -252,3 +252,23 @@
-  png_image_write_to_memory @245
-  png_get_eXIf @246
+Index: scripts/symbols.def
+===================================================================
+--- scripts/symbols.def
++++ scripts/symbols.def
+@@ -254,3 +254,23 @@
   png_set_eXIf @247
-+ png_get_acTL @248
-+ png_set_acTL @249
-+ png_get_num_frames @250
-+ png_get_num_plays @251
-+ png_get_next_frame_fcTL @252
-+ png_set_next_frame_fcTL @253
-+ png_get_next_frame_width @254
-+ png_get_next_frame_height @255
-+ png_get_next_frame_x_offset @256
-+ png_get_next_frame_y_offset @257
-+ png_get_next_frame_delay_num @258
-+ png_get_next_frame_delay_den @259
-+ png_get_next_frame_dispose_op @260
-+ png_get_next_frame_blend_op @261
-+ png_get_first_frame_is_hidden @262
-+ png_set_first_frame_is_hidden @263
-+ png_read_frame_head @264
-+ png_set_progressive_frame_fn @265
-+ png_write_frame_head @266
-+ png_write_frame_tail @267
+  png_get_eXIf_1 @248
+  png_set_eXIf_1 @249
++ png_get_acTL @250
++ png_set_acTL @251
++ png_get_num_frames @252
++ png_get_num_plays @253
++ png_get_next_frame_fcTL @254
++ png_set_next_frame_fcTL @255
++ png_get_next_frame_width @256
++ png_get_next_frame_height @257
++ png_get_next_frame_x_offset @258
++ png_get_next_frame_y_offset @259
++ png_get_next_frame_delay_num @260
++ png_get_next_frame_delay_den @261
++ png_get_next_frame_dispose_op @262
++ png_get_next_frame_blend_op @263
++ png_get_first_frame_is_hidden @264
++ png_set_first_frame_is_hidden @265
++ png_read_frame_head @266
++ png_set_progressive_frame_fn @267
++ png_write_frame_head @268
++ png_write_frame_tail @269