[libpng15] Imported from libpng-1.5.23.tar

[libpng15] Imported from libpng-1.5.23rc03.tar
[libpng15] Removed WEIGHTED_FILTER paragraph from the man page.
2025-07-10 18:04:09 +02:00 · 2015-07-22 22:40:33 -05:00 · 2015-07-15 21:23:58 -05:00 · 2015-07-13 14:42:14 -05:00 · 2015-07-13 08:30:27 -05:00 · 2015-07-13 07:06:07 -05:00
37 changed files with 351 additions and 1094 deletions
--- a/60
+++ b/60
@@ -1,5 +1,5 @@

-Libpng 1.5.22 - March 26, 2015
+Libpng 1.5.23 - July 23, 2015

 This is a public release of libpng, intended for use in production codes.

@@ -8,46 +8,40 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script

-   libpng-1.5.22.tar.xz (LZMA-compressed, recommended)
-   libpng-1.5.22.tar.gz
-   libpng-1.5.22.tar.bz2
+   libpng-1.5.23.tar.xz (LZMA-compressed, recommended)
+   libpng-1.5.23.tar.gz
+   libpng-1.5.23.tar.bz2

 Source files with CRLF line endings (for Windows), without the
 "configure" script

-   lpng1522.7z  (LZMA-compressed, recommended)
-   lpng1522.zip
+   lpng1523.7z  (LZMA-compressed, recommended)
+   lpng1523.zip

 Other information:

-   libpng-1.5.22-README.txt
-   libpng-1.5.22-LICENSE.txt
-   libpng-1.5.22-*.asc (armored detached GPG signatures)
+   libpng-1.5.23-README.txt
+   libpng-1.5.23-LICENSE.txt
+   libpng-1.5.23-*.asc (armored detached GPG signatures)

-Changes since the last public release (1.5.21):
-
-  Regenerated configure scripts with libtool-2.4.4
-  Made the check for out-of-range values in png_set_tRNS() detect
-    values that are exactly 2^bit_depth, and work on 16-bit platforms.
-  Quieted some warnings from Coverity-scan.
-  Merged pngtest.c with libpng-1.6.17/pngtest.c
-  Display user limits in the output from pngtest.
-  Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column
-    and 1-million-row default limits in pnglibconf.dfa, that can be reset
-    by the user at build time or run time.  This provides a more robust
-    defense against DOS and as-yet undiscovered overflows.
-  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
-  Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
-  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
-  Removed some comments that the configure script did not handle
-    properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt.
-  Merged png_free_data() with libpng-1.6.17
-  Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF
-    for consistency, and remove some useless tests (Alexey Petruchik).
-  Remove pnglibconf.h, pnglibconf.c, and pnglibconf.out instead of
-    pnglibconf.* in "make clean" (Cosmin).
-  Fix incorrect calculation of maximum number of unknown chunks or
-    sPLT chunks to be stored (John Bowler).
+Changes since the last public release (1.5.22):
+  Removed unused PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED definitions
+    from pnglibconf.h.prebuilt (Andrew Church).
+  Replaced "unexpected" with an integer in pngset.c where a long was
+    expected, to avoid a compiler warning when PNG_DEBUG > 1.
+  Fix typecast in a png_debug2() statement in png_set_text_2() to
+    avoid a compiler warning in PNG_DEBUG builds.
+  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds.
+  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
+    report from Christopher Ferris).
+  Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the
+    compiled library size. It never worked properly and as far as we can
+    tell, no one uses it. The png_set_filter_heuristics() and
+    png_set_filter_heuristics_fixed() APIs are retained but deprecated
+    and do nothing.
+  Quieted Coverity issues in pngvalid.c.
+  Removed non-working progressive reader 'skip' function.
+  Belatedly added Mans Rullgard to the list of Contributing Authors.

 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
--- a/91
+++ b/91
@@ -1,11 +1,14 @@
 #if 0
 CHANGES - changes for libpng

-Version 0.2
+version 0.1 [March 29, 1995]
+  initial work-in-progress release
+
+version 0.2 [April 1, 1995]
  added reader into png.h
  fixed small problems in stub file

-Version 0.3
+version 0.3 [April 8, 1995]
  added pull reader
  split up pngwrite.c to several files
  added pnglib.txt
@@ -14,9 +17,9 @@ Version 0.3
  fixed some bugs in writer
  interfaced with zlib 0.5
  added K&R support
-  added check for 64 KB blocks for 16-bit machines
+  added check for 64 KB blocks for 16 bit machines

-Version 0.4
+version 0.4 [April 26, 1995]
  cleaned up code and commented code
  simplified time handling into png_time
  created png_color_16 and png_color_8 to handle color needs
@@ -27,28 +30,29 @@ Version 0.4
  cleaned up zTXt reader and writer (using zlib's Reset functions)
  split transformations into pngrtran.c and pngwtran.c

-Version 0.5
+version 0.5 [April 30, 1995]
  interfaced with zlib 0.8
  fixed many reading and writing bugs
  saved using 3 spaces instead of tabs

-Version 0.6
+version 0.6 [May 1, 1995]
+  first beta release
  added png_large_malloc() and png_large_free()
  added png_size_t
  cleaned up some compiler warnings
  added png_start_read_image()

-Version 0.7
+version 0.7 [June 24, 1995]
  cleaned up lots of bugs
  finished dithering and other stuff
  added test program
  changed name from pnglib to libpng

-Version 0.71 [June, 1995]
+version 0.71 [June 26, 1995]
  changed pngtest.png for zlib 0.93
  fixed error in libpng.txt and example.c

-Version 0.8
+version 0.8 [August 20, 1995]
  cleaned up some bugs
  added png_set_filler()
  split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
@@ -158,7 +162,7 @@ Version 0.95 [March, 1997]
  Added new pCAL chunk read/write support
  Added experimental filter selection weighting (Greg Roelofs)
  Removed old png_set_rgbx() and png_set_xrgb() functions that have been
-     obsolete for about 2 years now (use png_set_filler() instead)
+    obsolete for about 2 years now (use png_set_filler() instead)
  Added macros to read 16- and 32-bit ints directly from buffer, to be
    used only on those systems that support it (namely PowerPC and 680x0)
    With some testing, this may become the default for MACOS/PPC systems.
@@ -440,7 +444,7 @@ Version 1.0.3 [January 14, 1999]

 Version 1.0.3a [August 12, 1999]
  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
-     if an attempt is made to read an interlaced image when it's not supported.
+    if an attempt is made to read an interlaced image when it's not supported.
  Added check if png_ptr->trans is defined before freeing it in pngread.c
  Modified the Y2K statement to include versions back to version 0.71
  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
@@ -448,7 +452,7 @@ Version 1.0.3a [August 12, 1999]
  Replaced leading blanks with tab characters in makefile.hux
  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
  Changed (float)red and (float)green to (double)red, (double)green
-     in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+    in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
  Updated documentation to refer to the PNG-1.2 specification.
@@ -491,7 +495,7 @@ Version 1.0.3d [September 4, 1999]
  Added new png_expand functions to scripts/pngdef.pas and pngos2.def
  Added a demo read_user_transform_fn that examines the row filters in pngtest.c

-Version 1.0.4 [September 24, 1999]
+Version 1.0.4 [September 24, 1999, not distributed publicly]
  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
  Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
  Made several minor corrections to pngtest.c
@@ -518,6 +522,7 @@ Version 1.0.4c [October 1, 1999]
  Added a "png_check_version" function in png.c and pngtest.c that will generate
    a helpful compiler error if an old png.h is found in the search path.
  Changed type of png_user_transform_depth|channels from int to png_byte.
+  Added "Libpng is OSI Certified Open Source Software" statement to png.h

 Version 1.0.4d [October 6, 1999]
  Changed 0.45 to 0.45455 in png_set_sRGB()
@@ -904,7 +909,7 @@ Version 1.0.7 [July 1, 2000]
 Version 1.0.8beta1 [July 8, 2000]
  Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
  Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
-     pngwutil.c.
+    pngwutil.c.
  Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
  Removed unused "#include <assert.h>" from png.c
  Added WindowsCE support.
@@ -912,12 +917,12 @@ Version 1.0.8beta1 [July 8, 2000]

 Version 1.0.8beta2 [July 10, 2000]
  Added project files to the wince directory and made further revisions
-     of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
+    of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.

 Version 1.0.8beta3 [July 11, 2000]
  Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
-     for indexed-color input files to avoid potential double-freeing trans array
-     under some unusual conditions; problem was introduced in version 1.0.6f.
+    for indexed-color input files to avoid potential double-freeing trans array
+    under some unusual conditions; problem was introduced in version 1.0.6f.
  Further revisions to pngtest.c and files in the wince subdirectory.

 Version 1.0.8beta4 [July 14, 2000]
@@ -1089,16 +1094,16 @@ Version 1.2.0beta3 [May 17, 2001]

 Version 1.2.0beta4 [June 23, 2001]
  Check for missing profile length field in iCCP chunk and free chunk_data
-     in case of truncated iCCP chunk.
+    in case of truncated iCCP chunk.
  Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
  Bumped dll-number from 2 to 3 in makefile.cygwin
  Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
-     if user attempts to run it on an 8-bit display.
+    if user attempts to run it on an 8-bit display.
  Updated contrib/gregbook
  Use png_malloc instead of png_zalloc to allocate palette in pngset.c
  Updated makefile.ibmc
  Added some typecasts to eliminate gcc 3.0 warnings.  Changed prototypes
-     of png_write_oFFS width and height from png_uint_32 to png_int_32.
+    of png_write_oFFS width and height from png_uint_32 to png_int_32.
  Updated example.c
  Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c

@@ -1106,9 +1111,9 @@ Version 1.2.0beta5 [August 8, 2001]
  Revised contrib/gregbook
  Revised makefile.gcmmx
  Revised pnggccrd.c to conditionally compile some thread-unsafe code only
-     when PNG_THREAD_UNSAFE_OK is defined.
+    when PNG_THREAD_UNSAFE_OK is defined.
  Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
-     value exceeding 2^bit_depth-1
+    value exceeding 2^bit_depth-1
  Revised makefile.sgi and makefile.sggcc
  Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
  Removed restriction that do_invert_mono only operate on 1-bit opaque files
@@ -1449,8 +1454,9 @@ Version 1.2.6beta4 [July 28, 2004]
  Use png_malloc instead of png_zalloc to allocate the pallete.

 Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
-  Fixed buffer overflow vulnerability in png_handle_tRNS()
-  Fixed integer arithmetic overflow vulnerability in png_read_png().
+  Fixed buffer overflow vulnerability (CVE-2004-0597) in png_handle_tRNS().
+  Fixed NULL dereference vulnerability (CVE-2004-0598) in png_handle_iCCP().
+  Fixed integer overflow vulnerability (CVE-2004-0599) in png_read_png().
  Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
    duplicate chunk types to go undetected.
  Fixed some timestamps in the -config version
@@ -1493,7 +1499,7 @@ Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]

 Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
  Moved  "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
-     section of png.h where they were inadvertently placed in version rc3.
+    section of png.h where they were inadvertently placed in version rc3.

 Version 1.2.6 and 1.0.16 [August 15, 2004]
  Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
@@ -2325,7 +2331,7 @@ Version 1.4.0beta63 [June 15, 2009]
 Version 1.4.0beta64 [June 24, 2009]
  Eliminated PNG_LEGACY_SUPPORTED code.
  Moved the various unknown chunk macro definitions outside of the
-     PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.
+    PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.

 Version 1.4.0beta65 [June 26, 2009]
  Added a reference to the libpng license in each file.
@@ -4334,6 +4340,39 @@ Version 1.5.22rc04 [March 16, 2015]
 Version 1.5.22 [March 26, 2015]
  No changes.

+Version 1.5.23beta01 [May 21, 2015]
+  Removed unused PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED definitions
+    from pnglibconf.h.prebuilt (Andrew Church).
+  Replaced "unexpected" with an integer in pngset.c where a long was
+    expected, to avoid a compiler warning when PNG_DEBUG > 1.
+  Fix typecast in a png_debug2() statement in png_set_text_2() to
+    avoid a compiler warning in PNG_DEBUG builds.
+  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds.
+  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
+    report from Christopher Ferris).
+
+Version 1.5.23beta02 [June 30, 2015]
+  Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the
+    compiled library size. It never worked properly and as far as we can
+    tell, no one uses it. The png_set_filter_heuristics() and
+    png_set_filter_heuristics_fixed() APIs are retained but deprecated
+    and do nothing.
+  Quieted Coverity issues in pngvalid.c.
+  Removed non-working progressive reader 'skip' function.
+
+Version 1.5.23rc01 [July 9, 2015]
+  Belatedly added Mans Rullgard to the list of Contributing Authors.
+
+Version 1.5.23rc02 [July 12, 2015]
+  Restored unused FILTER_HEURISTIC macros removed at libpng-1.5.23beta02
+    to png.h to avoid compatibility warnings.
+
+Version 1.5.23rc03 [July 15, 2015]
+  Minor editing of the man page.
+
+Version 1.5.23 [July 23, 2015]
+  No changes.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,7 @@ enable_testing()

 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 5)
-set(PNGLIB_RELEASE 22)
+set(PNGLIB_RELEASE 23)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})

@@ -224,7 +224,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
  set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 15.${PNGLIB_RELEASE}.1.5.22
+#   VERSION 15.${PNGLIB_RELEASE}.1.5.23
    VERSION 15.${PNGLIB_RELEASE}.0
    SOVERSION 15
    CLEAN_DIRECT_OUTPUT 1)
--- a/47
+++ b/47
@@ -10,20 +10,15 @@ this sentence.

 This code is released under the libpng license.

-libpng versions 1.2.6, August 15, 2004, through 1.5.22, March 26, 2015, are
-Copyright (c) 2004, 2006-2015 Glenn Randers-Pehrson, and are
-distributed according to the same disclaimer and license as libpng-1.2.5
-with the following individual added to the list of Contributing Authors
-
-   Cosmin Truta
-
-libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
-Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+libpng versions 1.0.7, July 1, 2000, through 1.5.23, July 23, 2015, are
+Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.0.6
-with the following individuals added to the list of Contributing Authors
+with the following individuals added to the list of Contributing Authors:

   Simon-Pierre Cadieux
   Eric S. Raymond
+   Mans Rullgard
+   Cosmin Truta
   Gilles Vollant

 and with the following additions to the disclaimer:
@@ -36,17 +31,17 @@ and with the following additions to the disclaimer:
   the user.

 libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
-Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
-distributed according to the same disclaimer and license as libpng-0.96,
-with the following individuals added to the list of Contributing Authors:
+Copyright (c) 1998-2000 Glenn Randers-Pehrson, and are distributed according
+to the same disclaimer and license as libpng-0.96, with the following
+individuals added to the list of Contributing Authors:

   Tom Lane
   Glenn Randers-Pehrson
   Willem van Schaik

 libpng versions 0.89, June 1996, through 0.96, May 1997, are
-Copyright (c) 1996, 1997 Andreas Dilger
-Distributed according to the same disclaimer and license as libpng-0.88,
+Copyright (c) 1996-1997 Andreas Dilger, and are
+distributed according to the same disclaimer and license as libpng-0.88,
 with the following individuals added to the list of Contributing Authors:

   John Bowler
@@ -57,7 +52,7 @@ with the following individuals added to the list of Contributing Authors:
   Tom Tanner

 libpng versions 0.5, May 1995, through 0.88, January 1996, are
-Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.

 For the purposes of this copyright and license, "Contributing Authors"
 is defined as the following set of individuals:
@@ -80,13 +75,13 @@ Permission is hereby granted to use, copy, modify, and distribute this
 source code, or portions hereof, for any purpose, without fee, subject
 to the following restrictions:

-1. The origin of this source code must not be misrepresented.
+  1. The origin of this source code must not be misrepresented.

-2. Altered versions must be plainly marked as such and must not
-   be misrepresented as being the original source.
+  2. Altered versions must be plainly marked as such and must not
+     be misrepresented as being the original source.

-3. This Copyright notice may not be removed or altered from any
-   source or altered source distribution.
+  3. This Copyright notice may not be removed or altered from any
+     source or altered source distribution.

 The Contributing Authors and Group 42, Inc. specifically permit, without
 fee, and encourage the use of this source code as a component to
@@ -94,18 +89,18 @@ supporting the PNG file format in commercial products.  If you use this
 source code in a product, acknowledgment is not required but would be
 appreciated.

-
 A "png_get_copyright" function is available, for convenient use in "about"
 boxes and the like:

-   printf("%s",png_get_copyright(NULL));
+   printf("%s", png_get_copyright(NULL));

 Also, the PNG logo (in PNG format, of course) is supplied in the
 files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).

-Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
-certification mark of the Open Source Initiative.
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+a certification mark of the Open Source Initiative. OSI has not addressed
+the additional disclaimers inserted at version 1.0.7.

 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 26, 2015
+July 23, 2015
--- a/4
+++ b/4
@@ -1,4 +1,4 @@
-README for libpng version 1.5.22 - March 26, 2015 (shared library 15.0)
+README for libpng version 1.5.23 - July 23, 2015 (shared library 15.0)
 See the note about version numbers near the top of png.h

 See INSTALL for instructions on how to install libpng.
@@ -134,7 +134,7 @@ and ...".  If in doubt, send questions to me.  I'll bounce them
 to others, if necessary.

 Please do not send suggestions on how to change PNG.  We have
-been discussing PNG for nineteen years now, and it is official and
+been discussing PNG for twenty years now, and it is official and
 finished.  If you have suggestions for libpng, however, I'll
 gladly listen.  Even if your suggestion is not used immediately,
 it may be used later.
--- a/24
+++ b/24
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for libpng 1.5.22.
+# Generated by GNU Autoconf 2.69 for libpng 1.5.23.
 #
 # Report bugs to <png-mng-implement@lists.sourceforge.net>.
 #
@@ -590,8 +590,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='libpng'
 PACKAGE_TARNAME='libpng'
-PACKAGE_VERSION='1.5.22'
-PACKAGE_STRING='libpng 1.5.22'
+PACKAGE_VERSION='1.5.23'
+PACKAGE_STRING='libpng 1.5.23'
 PACKAGE_BUGREPORT='png-mng-implement@lists.sourceforge.net'
 PACKAGE_URL=''

@@ -1354,7 +1354,7 @@ if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
-\`configure' configures libpng 1.5.22 to adapt to many kinds of systems.
+\`configure' configures libpng 1.5.23 to adapt to many kinds of systems.

 Usage: $0 [OPTION]... [VAR=VALUE]...

@@ -1424,7 +1424,7 @@ fi

 if test -n "$ac_init_help"; then
  case $ac_init_help in
-     short | recursive ) echo "Configuration of libpng 1.5.22:";;
+     short | recursive ) echo "Configuration of libpng 1.5.23:";;
   esac
  cat <<\_ACEOF

@@ -1579,7 +1579,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
  cat <<\_ACEOF
-libpng configure 1.5.22
+libpng configure 1.5.23
 generated by GNU Autoconf 2.69

 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -2002,7 +2002,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.

-It was created by libpng $as_me 1.5.22, which was
+It was created by libpng $as_me 1.5.23, which was
 generated by GNU Autoconf 2.69.  Invocation command line was

  $ $0 $@
@@ -2865,7 +2865,7 @@ fi

 # Define the identity of the package.
 PACKAGE='libpng'
- VERSION='1.5.22'
+ VERSION='1.5.23'


 cat >>confdefs.h <<_ACEOF
@@ -2982,10 +2982,10 @@ fi



-PNGLIB_VERSION=1.5.22
+PNGLIB_VERSION=1.5.23
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=5
-PNGLIB_RELEASE=22
+PNGLIB_RELEASE=23



@@ -14124,7 +14124,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by libpng $as_me 1.5.22, which was
+This file was extended by libpng $as_me 1.5.23, which was
 generated by GNU Autoconf 2.69.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
@@ -14190,7 +14190,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-libpng config.status 1.5.22
+libpng config.status 1.5.23
 configured by $0, generated by GNU Autoconf 2.69,
  with options \\"\$ac_cs_config\\"

--- a/configure.ac
+++ b/configure.ac
@@ -18,15 +18,15 @@ AC_PREREQ(2.59)

 dnl Version number stuff here:

-AC_INIT([libpng], [1.5.22], [png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng], [1.5.23], [png-mng-implement@lists.sourceforge.net])
 AM_INIT_AUTOMAKE([1.13 serial-tests subdir-objects])
 dnl stop configure from automagically running automake
 AM_MAINTAINER_MODE

-PNGLIB_VERSION=1.5.22
+PNGLIB_VERSION=1.5.23
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=5
-PNGLIB_RELEASE=22
+PNGLIB_RELEASE=23

 dnl End of version number stuff

--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -1275,7 +1275,10 @@ store_current_palette(png_store *ps, int *npalette)
    * operation.)
    */
   if (ps->current == NULL)
+   {
      store_log(ps, ps->pread, "no current stream for palette", 1);
+      return NULL;
+   }

   /* The result may be null if there is no palette. */
   *npalette = ps->current->npalette;
@@ -5667,7 +5670,7 @@ image_transform_mod_end(PNG_CONST image_transform *this, image_pixel *that,
   else
   {
      that->alpha = scale; /* opaque */
-      that->alpha = 1;     /* Override this. */
+      that->alphaf = 1;    /* Override this. */
      that->alphae = 0;    /* It's exact ;-) */
   }
 }
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -1,6 +1,6 @@
 Libpng-manual.txt - A description on how to use and modify libpng

- libpng version 1.5.22 - March 26, 2015
+ libpng version 1.5.23 - July 23, 2015
 Updated and distributed by Glenn Randers-Pehrson
 <glennrp at users.sourceforge.net>
 Copyright (c) 1998-2014 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@ Libpng-manual.txt - A description on how to use and modify libpng

 Based on:

- libpng versions 0.97, January 1998, through 1.5.22 - March 26, 2015
+ libpng versions 0.97, January 1998, through 1.5.23 - July 23, 2015
 Updated and distributed by Glenn Randers-Pehrson
 Copyright (c) 1998-2014 Glenn Randers-Pehrson

@@ -3754,41 +3754,6 @@ is called for the first time.)
              same as the value of filter_method used
              in png_set_IHDR().

-It is also possible to influence how libpng chooses from among the
-available filters.  This is done in one or both of two ways - by
-telling it how important it is to keep the same filter for successive
-rows, and by telling it the relative computational costs of the filters.
-
-    double weights[3] = {1.5, 1.3, 1.1},
-       costs[PNG_FILTER_VALUE_LAST] =
-       {1.0, 1.3, 1.3, 1.5, 1.7};
-
-    png_set_filter_heuristics(png_ptr,
-       PNG_FILTER_HEURISTIC_WEIGHTED, 3,
-       weights, costs);
-
-The weights are multiplying factors that indicate to libpng that the
-row filter should be the same for successive rows unless another row filter
-is that many times better than the previous filter.  In the above example,
-if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
-"sum of absolute differences" 1.5 x 1.3 times higher than other filters
-and still be chosen, while the NONE filter could have a sum 1.1 times
-higher than other filters and still be chosen.  Unspecified weights are
-taken to be 1.0, and the specified weights should probably be declining
-like those above in order to emphasize recent filters over older filters.
-
-The filter costs specify for each filter type a relative decoding cost
-to be considered when selecting row filters.  This means that filters
-with higher costs are less likely to be chosen over filters with lower
-costs, unless their "sum of absolute differences" is that much smaller.
-The costs do not necessarily reflect the exact computational speeds of
-the various filters, since this would unduly influence the final image
-size.
-
-Note that the numbers above were invented purely for this example and
-are given only to help explain the function usage.  Little testing has
-been done to find optimum values for either the costs or the weights.
-
 Requesting debug printout

 The macro definition PNG_DEBUG can be used to request debugging
@@ -4535,13 +4500,13 @@ Other rules can be inferred by inspecting the libpng source.

 XIV. Y2K Compliance in libpng

-March 26, 2015
+July 23, 2015

 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 1.5.22 are Y2K compliant.  It is my belief that earlier
+upward through 1.5.23 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
--- a/libpng.3
+++ b/libpng.3
@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "March 26, 2015"
+.TH LIBPNG 3 "July 23, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.5.22
+libpng \- Portable Network Graphics (PNG) Reference Library 1.5.23
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -121,6 +121,8 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.22

 \fBpng_byte png_get_libpng_ver (png_const_structp \fIpng_ptr\fP\fB);\fP

+\fBint png_get_palette_max(png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
+
 \fBpng_voidp png_get_mem_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP

 \fBpng_uint_32 png_get_oFFs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*offset_x\fP\fB, png_uint_32 \fP\fI*offset_y\fP\fB, int \fI*unit_type\fP\fB);\fP
@@ -357,6 +359,8 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.22

 \fBvoid png_set_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIoffset_x\fP\fB, png_uint_32 \fP\fIoffset_y\fP\fB, int \fIunit_type\fP\fB);\fP

+\fBint png_set_option(png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIoption\fP\fB, int \fIonoff\fP\fB);\fP
+
 \fBvoid png_set_packing (png_structp \fIpng_ptr\fP\fB);\fP

 \fBvoid png_set_packswap (png_structp \fIpng_ptr\fP\fB);\fP
@@ -492,7 +496,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 Libpng-manual.txt - A description on how to use and modify libpng

- libpng version 1.5.22 - March 26, 2015
+ libpng version 1.5.23 - July 23, 2015
 Updated and distributed by Glenn Randers-Pehrson
 <glennrp at users.sourceforge.net>
 Copyright (c) 1998-2014 Glenn Randers-Pehrson
@@ -503,7 +507,7 @@ Libpng-manual.txt - A description on how to use and modify libpng

 Based on:

- libpng versions 0.97, January 1998, through 1.5.22 - March 26, 2015
+ libpng versions 0.97, January 1998, through 1.5.23 - July 23, 2015
 Updated and distributed by Glenn Randers-Pehrson
 Copyright (c) 1998-2014 Glenn Randers-Pehrson

@@ -4246,41 +4250,6 @@ is called for the first time.)
              same as the value of filter_method used
              in png_set_IHDR().

-It is also possible to influence how libpng chooses from among the
-available filters.  This is done in one or both of two ways - by
-telling it how important it is to keep the same filter for successive
-rows, and by telling it the relative computational costs of the filters.
-
-    double weights[3] = {1.5, 1.3, 1.1},
-       costs[PNG_FILTER_VALUE_LAST] =
-       {1.0, 1.3, 1.3, 1.5, 1.7};
-
-    png_set_filter_heuristics(png_ptr,
-       PNG_FILTER_HEURISTIC_WEIGHTED, 3,
-       weights, costs);
-
-The weights are multiplying factors that indicate to libpng that the
-row filter should be the same for successive rows unless another row filter
-is that many times better than the previous filter.  In the above example,
-if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
-"sum of absolute differences" 1.5 x 1.3 times higher than other filters
-and still be chosen, while the NONE filter could have a sum 1.1 times
-higher than other filters and still be chosen.  Unspecified weights are
-taken to be 1.0, and the specified weights should probably be declining
-like those above in order to emphasize recent filters over older filters.
-
-The filter costs specify for each filter type a relative decoding cost
-to be considered when selecting row filters.  This means that filters
-with higher costs are less likely to be chosen over filters with lower
-costs, unless their "sum of absolute differences" is that much smaller.
-The costs do not necessarily reflect the exact computational speeds of
-the various filters, since this would unduly influence the final image
-size.
-
-Note that the numbers above were invented purely for this example and
-are given only to help explain the function usage.  Little testing has
-been done to find optimum values for either the costs or the weights.
-
 .SS Requesting debug printout

 The macro definition PNG_DEBUG can be used to request debugging
@@ -5027,13 +4996,13 @@ Other rules can be inferred by inspecting the libpng source.

 .SH XIV. Y2K Compliance in libpng

-March 26, 2015
+July 23, 2015

 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 1.5.22 are Y2K compliant.  It is my belief that earlier
+upward through 1.5.23 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
@@ -5280,6 +5249,9 @@ the first widely used release:
 1.5.22beta01-04     15    10522  15.so.15.22[.0]
 1.5.22rc01-04       15    10522  15.so.15.22[.0]
 1.5.22              15    10522  15.so.15.22[.0]
+ 1.5.23beta01-02     15    10523  15.so.15.23[.0]
+ 1.5.23rc01-03       15    10523  15.so.15.23[.0]
+ 1.5.23              15    10523  15.so.15.23[.0]

 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -5336,7 +5308,7 @@ possible without all of you.

 Thanks to Frank J. T. Wojcik for helping with the documentation.

-Libpng version 1.5.22 - March 26, 2015:
+Libpng version 1.5.23 - July 23, 2015:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).

@@ -5359,44 +5331,38 @@ this sentence.

 This code is released under the libpng license.

-libpng versions 1.2.6, August 15, 2004, through 1.5.22, March 26, 2015, are
-Copyright (c) 2004,2006-2015 Glenn Randers-Pehrson, and are
-distributed according to the same disclaimer and license as libpng-1.2.5
-with the following individual added to the list of Contributing Authors
-
-   Cosmin Truta
-
-libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
-Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+libpng versions 1.0.7, July 1, 2000, through 1.5.23, July 23, 2015, are
+Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.0.6
-with the following individuals added to the list of Contributing Authors
+with the following individuals added to the list of Contributing Authors:

   Simon-Pierre Cadieux
   Eric S. Raymond
+   Mans Rullgard
+   Cosmin Truta
   Gilles Vollant

 and with the following additions to the disclaimer:

-   There is no warranty against interference with your
-   enjoyment of the library or against infringement.
-   There is no warranty that our efforts or the library
-   will fulfill any of your particular purposes or needs.
-   This library is provided with all faults, and the entire
-   risk of satisfactory quality, performance, accuracy, and
-   effort is with the user.
+   There is no warranty against interference with your enjoyment of the
+   library or against infringement.  There is no warranty that our
+   efforts or the library will fulfill any of your particular purposes
+   or needs.  This library is provided with all faults, and the entire
+   risk of satisfactory quality, performance, accuracy, and effort is with
+   the user.

 libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
-Copyright (c) 1998, 1999 Glenn Randers-Pehrson
-Distributed according to the same disclaimer and license as libpng-0.96,
-with the following individuals added to the list of Contributing Authors:
+Copyright (c) 1998-2000 Glenn Randers-Pehrson, and are distributed according
+to the same disclaimer and license as libpng-0.96, with the following
+individuals added to the list of Contributing Authors:

   Tom Lane
   Glenn Randers-Pehrson
   Willem van Schaik

 libpng versions 0.89, June 1996, through 0.96, May 1997, are
-Copyright (c) 1996, 1997 Andreas Dilger
-Distributed according to the same disclaimer and license as libpng-0.88,
+Copyright (c) 1996-1997 Andreas Dilger, and are
+distributed according to the same disclaimer and license as libpng-0.88,
 with the following individuals added to the list of Contributing Authors:

   John Bowler
@@ -5407,7 +5373,7 @@ with the following individuals added to the list of Contributing Authors:
   Tom Tanner

 libpng versions 0.5, May 1995, through 0.88, January 1996, are
-Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.

 For the purposes of this copyright and license, "Contributing Authors"
 is defined as the following set of individuals:
@@ -5430,13 +5396,13 @@ Permission is hereby granted to use, copy, modify, and distribute this
 source code, or portions hereof, for any purpose, without fee, subject
 to the following restrictions:

-1. The origin of this source code must not be misrepresented.
+  1. The origin of this source code must not be misrepresented.

-2. Altered versions must be plainly marked as such and
-   must not be misrepresented as being the original source.
+  2. Altered versions must be plainly marked as such and must not
+     be misrepresented as being the original source.

-3. This Copyright notice may not be removed or altered from
-   any source or altered source distribution.
+  3. This Copyright notice may not be removed or altered from any
+     source or altered source distribution.

 The Contributing Authors and Group 42, Inc. specifically permit, without
 fee, and encourage the use of this source code as a component to
@@ -5444,21 +5410,21 @@ supporting the PNG file format in commercial products.  If you use this
 source code in a product, acknowledgment is not required but would be
 appreciated.

-
 A "png_get_copyright" function is available, for convenient use in "about"
 boxes and the like:

-   printf("%s",png_get_copyright(NULL));
+   printf("%s", png_get_copyright(NULL));

 Also, the PNG logo (in PNG format, of course) is supplied in the
 files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).

-Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
-certification mark of the Open Source Initiative.
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+a certification mark of the Open Source Initiative. OSI has not addressed
+the additional disclaimers inserted at version 1.0.7.

 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 26, 2015
+July 23, 2015

 .\" end of man page

--- a/libpngpf.3
+++ b/libpngpf.3
@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "March 26, 2015"
+.TH LIBPNGPF 3 "July 23, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.5.22
+libpng \- Portable Network Graphics (PNG) Reference Library 1.5.23
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
--- a/png.5
+++ b/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "March 26, 2015"
+.TH PNG 5 "July 23, 2015"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
--- a/png.c
+++ b/png.c
@@ -1,7 +1,7 @@

 /* png.c - location for general purpose libpng functions
 *
- * Last changed in libpng 1.5.22 [March 26, 2015]
+ * Last changed in libpng 1.5.23 [July 23, 2015]
 * Copyright (c) 1998-2015 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_5_22 Your_png_h_is_not_version_1_5_22;
+typedef png_libpng_version_1_5_23 Your_png_h_is_not_version_1_5_23;

 /* Tells libpng that we have already handled the first "num_bytes" bytes
 * of the PNG file signature.  If the PNG data is embedded into another
@@ -648,13 +648,13 @@ png_get_copyright(png_const_structp png_ptr)
 #else
 #  ifdef __STDC__
   return PNG_STRING_NEWLINE \
-     "libpng version 1.5.22 - March 26, 2015" PNG_STRING_NEWLINE \
+     "libpng version 1.5.23 - July 23, 2015" PNG_STRING_NEWLINE \
     "Copyright (c) 1998-2015 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 1.5.22 - March 26, 2015\
+      return "libpng version 1.5.23 - July 23, 2015\
      Copyright (c) 1998-2015 Glenn Randers-Pehrson\
      Copyright (c) 1996-1997 Andreas Dilger\
      Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -885,7 +885,8 @@ int png_XYZ_from_xy(png_XYZ *XYZ, png_xy xy)

   /* Check xy and, implicitly, z.  Note that wide gamut color spaces typically
    * have end points with 0 tristimulus values (these are impossible end
-    * points, but they are used to cover the possible colors.)
+    * points, but they are used to cover the possible colors).  We check
+    * xy.whitey against 5, not 0, to avoid a possible integer overflow.
    */
   if (xy.redx < 0 || xy.redx > PNG_FP_1) return 1;
   if (xy.redy < 0 || xy.redy > PNG_FP_1-xy.redx) return 1;
@@ -894,7 +895,7 @@ int png_XYZ_from_xy(png_XYZ *XYZ, png_xy xy)
   if (xy.bluex < 0 || xy.bluex > PNG_FP_1) return 1;
   if (xy.bluey < 0 || xy.bluey > PNG_FP_1-xy.bluex) return 1;
   if (xy.whitex < 0 || xy.whitex > PNG_FP_1) return 1;
-   if (xy.whitey < 0 || xy.whitey > PNG_FP_1-xy.whitex) return 1;
+   if (xy.whitey < 5 || xy.whitey > PNG_FP_1-xy.whitex) return 1;

   /* The reverse calculation is more difficult because the original tristimulus
    * value had 9 independent values (red,green,blue)x(X,Y,Z) however only 8
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@

 /* png.h - header file for PNG reference library
 *
- * libpng version 1.5.22, March 26, 2015
+ * libpng version 1.5.23, July 23, 2015
 *
 * Copyright (c) 1998-2015 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 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.5.22, March 26, 2015: Glenn
+ *   libpng versions 0.97, January 1998, through 1.5.23, July 23, 2015: Glenn
 *   See also "Contributing Authors", below.
 *
 * Note about libpng version numbers:
@@ -209,6 +209,9 @@
 *    1.5.22beta01-04         15    10522  15.so.15.22[.0]
 *    1.5.22rc01-04           15    10522  15.so.15.22[.0]
 *    1.5.22                  15    10522  15.so.15.22[.0]
+ *    1.5.23beta01-02         15    10523  15.so.15.23[.0]
+ *    1.5.23rc01-03           15    10523  15.so.15.23[.0]
+ *    1.5.23                  15    10523  15.so.15.23[.0]
 *
 *   Henceforth the source version will match the shared-library major
 *   and minor numbers; the shared-library major version number will be
@@ -240,20 +243,15 @@
 *
 * This code is released under the libpng license.
 *
- * libpng versions 1.2.6, August 15, 2004, through 1.5.22, March 26, 2015, are
- * Copyright (c) 2004, 2006-2015 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-1.2.5
- * with the following individual added to the list of Contributing Authors:
- *
- *    Cosmin Truta
- *
- * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
- * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+ * libpng versions 1.0.7, July 1, 2000, through 1.5.23, July 23, 2015, are
+ * Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, and are
 * distributed according to the same disclaimer and license as libpng-1.0.6
 * with the following individuals added to the list of Contributing Authors:
 *
 *    Simon-Pierre Cadieux
 *    Eric S. Raymond
+ *    Mans Rullgard
+ *    Cosmin Truta
 *    Gilles Vollant
 *
 * and with the following additions to the disclaimer:
@@ -266,17 +264,17 @@
 *    the user.
 *
 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
- * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
- * distributed according to the same disclaimer and license as libpng-0.96,
- * with the following individuals added to the list of Contributing Authors:
+ * Copyright (c) 1998-2000 Glenn Randers-Pehrson, and are distributed according
+ * to the same disclaimer and license as libpng-0.96, with the following
+ * individuals added to the list of Contributing Authors:
 *
 *    Tom Lane
 *    Glenn Randers-Pehrson
 *    Willem van Schaik
 *
 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Distributed according to the same disclaimer and license as libpng-0.88,
+ * Copyright (c) 1996-1997 Andreas Dilger, and are
+ * distributed according to the same disclaimer and license as libpng-0.88,
 * with the following individuals added to the list of Contributing Authors:
 *
 *    John Bowler
@@ -287,7 +285,7 @@
 *    Tom Tanner
 *
 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 *
 * For the purposes of this copyright and license, "Contributing Authors"
 * is defined as the following set of individuals:
@@ -315,8 +313,8 @@
 *   2. Altered versions must be plainly marked as such and must not
 *      be misrepresented as being the original source.
 *
- *   3. This Copyright notice may not be removed or altered from
- *      any source or altered source distribution.
+ *   3. This Copyright notice may not be removed or altered from any
+ *      source or altered source distribution.
 *
 * The Contributing Authors and Group 42, Inc. specifically permit, without
 * fee, and encourage the use of this source code as a component to
@@ -329,15 +327,16 @@
 * A "png_get_copyright" function is available, for convenient use in "about"
 * boxes and the like:
 *
- *     printf("%s", png_get_copyright(NULL));
+ *    printf("%s", png_get_copyright(NULL));
 *
 * Also, the PNG logo (in PNG format, of course) is supplied in the
 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
 */

 /*
- * Libpng is OSI Certified Open Source Software.  OSI Certified is a
- * certification mark of the Open Source Initiative.
+ * Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+ * a certification mark of the Open Source Initiative. OSI has not addressed
+ * the additional disclaimers inserted at version 1.0.7.
 */

 /*
@@ -352,13 +351,13 @@
 * Y2K compliance in libpng:
 * =========================
 *
- *    March 26, 2015
+ *    July 23, 2015
 *
 *    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 1.5.22 are Y2K compliant.  It is my belief that
+ *    upward through 1.5.23 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
@@ -419,9 +418,9 @@
 */

 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.5.22"
+#define PNG_LIBPNG_VER_STRING "1.5.23"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.5.22 - March 26, 2015\n"
+     " libpng version 1.5.23 - July 23, 2015\n"

 #define PNG_LIBPNG_VER_SONUM   15
 #define PNG_LIBPNG_VER_DLLNUM  15
@@ -429,7 +428,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   5
-#define PNG_LIBPNG_VER_RELEASE 22
+#define PNG_LIBPNG_VER_RELEASE 23

 /* This should match the numeric part of the final component of
 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
@@ -460,7 +459,7 @@
 * 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 10522 /* 1.5.22 */
+#define PNG_LIBPNG_VER 10523 /* 1.5.23 */

 /* Library configuration: these options cannot be changed after
 * the library has been built.
@@ -582,7 +581,7 @@ 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_5_22;
+typedef char* png_libpng_version_1_5_23;

 /* Three color definitions.  The order of the red, green, and blue, (and the
 * exact size) is not important, although the size of the fields need to
@@ -1671,35 +1670,7 @@ PNG_EXPORT(67, void, png_set_filter,
 #define PNG_FILTER_VALUE_PAETH 4
 #define PNG_FILTER_VALUE_LAST  5

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
-/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
- * defines, either the default (minimum-sum-of-absolute-differences), or
- * the experimental method (weighted-minimum-sum-of-absolute-differences).
- *
- * Weights are factors >= 1.0, indicating how important it is to keep the
- * filter type consistent between rows.  Larger numbers mean the current
- * filter is that many times as likely to be the same as the "num_weights"
- * previous filters.  This is cumulative for each previous row with a weight.
- * There needs to be "num_weights" values in "filter_weights", or it can be
- * NULL if the weights aren't being specified.  Weights have no influence on
- * the selection of the first row filter.  Well chosen weights can (in theory)
- * improve the compression for a given image.
- *
- * Costs are factors >= 1.0 indicating the relative decoding costs of a
- * filter type.  Higher costs indicate more decoding expense, and are
- * therefore less likely to be selected over a filter with lower computational
- * costs.  There needs to be a value in "filter_costs" for each valid filter
- * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
- * setting the costs.  Costs try to improve the speed of decompression without
- * unduly increasing the compressed image size.
- *
- * A negative weight or cost indicates the default value is to be used, and
- * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
- * The default values for both weights and costs are currently 1.0, but may
- * change if good general weighting/cost heuristics can be found.  If both
- * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
- * to the UNWEIGHTED method, but with added encoding time/computation.
- */
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr,
    int heuristic_method, int num_weights, png_const_doublep filter_weights,
    png_const_doublep filter_costs))
@@ -1709,9 +1680,7 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
    filter_weights, png_const_fixed_point_p filter_costs))
 #endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */

-/* Heuristic used for row filter selection.  These defines should NOT be
- * changed.
- */
+/* The following are no longer used and will be removed from libpng-1.7: */
 #define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,7 +1,7 @@

 /* pngconf.h - machine configurable file for libpng
 *
- * libpng version 1.5.22, March 26, 2015
+ * libpng version 1.5.23, July 23, 2015
 *
 * Copyright (c) 1998-2013 Glenn Randers-Pehrson
 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
--- a/pngpread.c
+++ b/pngpread.c
@@ -1,8 +1,8 @@

 /* pngpread.c - read a png file in push mode
 *
- * Last changed in libpng 1.5.19 [August 21, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.23 [July 23, 2015]
+ * Copyright (c) 1998-2015 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.)
 *
@@ -19,7 +19,6 @@
 #define PNG_READ_SIG_MODE   0
 #define PNG_READ_CHUNK_MODE 1
 #define PNG_READ_IDAT_MODE  2
-#define PNG_SKIP_MODE       3
 #define PNG_READ_tEXt_MODE  4
 #define PNG_READ_zTXt_MODE  5
 #define PNG_READ_DONE_MODE  6
@@ -71,32 +70,15 @@ png_process_data_pause(png_structp png_ptr, int save)
 png_uint_32 PNGAPI
 png_process_data_skip(png_structp png_ptr)
 {
-   png_uint_32 remaining = 0;
-
-   if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE &&
-      png_ptr->skip_length > 0)
-   {
-      /* At the end of png_process_data the buffer size must be 0 (see the loop
-       * above) so we can detect a broken call here:
-       */
-      if (png_ptr->buffer_size != 0)
-         png_error(png_ptr,
-            "png_process_data_skip called inside png_process_data");
-
-      /* If is impossible for there to be a saved buffer at this point -
-       * otherwise we could not be in SKIP mode.  This will also happen if
-       * png_process_skip is called inside png_process_data (but only very
-       * rarely.)
-       */
-      if (png_ptr->save_buffer_size != 0)
-         png_error(png_ptr, "png_process_data_skip called with saved data");
-
-      remaining = png_ptr->skip_length;
-      png_ptr->skip_length = 0;
-      png_ptr->process_mode = PNG_READ_CHUNK_MODE;
-   }
-
-   return remaining;
+    /* TODO: Deprecate and remove this API.
+     * Somewhere the implementation of this seems to have been lost,
+     * or abandoned.  It was only to support some internal back-door access
+     * to png_struct) in libpng-1.4.x.
+     */
+   png_warning(png_ptr,
+       "png_process_data_skip is not implemented in any current version"
+       " of libpng");
+   return 0;
 }

 /* What we do with the incoming data depends on what we were previously
@@ -128,12 +110,6 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
         break;
      }

-      case PNG_SKIP_MODE:
-      {
-         png_push_crc_finish(png_ptr);
-         break;
-      }
-
      default:
      {
         png_ptr->buffer_size = 0;
@@ -564,76 +540,6 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
   png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
 }

-void /* PRIVATE */
-png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
-{
-   png_ptr->process_mode = PNG_SKIP_MODE;
-   png_ptr->skip_length = skip;
-}
-
-void /* PRIVATE */
-png_push_crc_finish(png_structp png_ptr)
-{
-   if (png_ptr->skip_length && png_ptr->save_buffer_size)
-   {
-      png_size_t save_size = png_ptr->save_buffer_size;
-      png_uint_32 skip_length = png_ptr->skip_length;
-
-      /* We want the smaller of 'skip_length' and 'save_buffer_size', but
-       * they are of different types and we don't know which variable has the
-       * fewest bits.  Carefully select the smaller and cast it to the type of
-       * the larger - this cannot overflow.  Do not cast in the following test
-       * - it will break on either 16 or 64 bit platforms.
-       */
-      if (skip_length < save_size)
-         save_size = (png_size_t)skip_length;
-
-      else
-         skip_length = (png_uint_32)save_size;
-
-      png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
-
-      png_ptr->skip_length -= skip_length;
-      png_ptr->buffer_size -= save_size;
-      png_ptr->save_buffer_size -= save_size;
-      png_ptr->save_buffer_ptr += save_size;
-   }
-
-   if (png_ptr->skip_length && png_ptr->current_buffer_size)
-   {
-      png_size_t save_size = png_ptr->current_buffer_size;
-      png_uint_32 skip_length = png_ptr->skip_length;
-
-      /* We want the smaller of 'skip_length' and 'current_buffer_size', here,
-       * the same problem exists as above and the same solution.
-       */
-      if (skip_length < save_size)
-         save_size = (png_size_t)skip_length;
-
-      else
-         skip_length = (png_uint_32)save_size;
-
-      png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
-
-      png_ptr->skip_length -= skip_length;
-      png_ptr->buffer_size -= save_size;
-      png_ptr->current_buffer_size -= save_size;
-      png_ptr->current_buffer_ptr += save_size;
-   }
-
-   if (!png_ptr->skip_length)
-   {
-      if (png_ptr->buffer_size < 4)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
-      png_crc_finish(png_ptr, 0);
-      png_ptr->process_mode = PNG_READ_CHUNK_MODE;
-   }
-}
-
 void PNGCBAPI
 png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
 {
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -1,8 +1,8 @@

 /* pngpriv.h - private declarations for use inside libpng
 *
- * Last changed in libpng 1.5.19 [August 21, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.23 [July 23, 2015]
+ * Copyright (c) 1998-2015 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.)
 *
@@ -1317,9 +1317,6 @@ PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
    png_infop info_ptr));
 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
-    png_uint_32 length));
-PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
    png_bytep buffer, png_size_t buffer_length));
--- a/pngread.c
+++ b/pngread.c
@@ -1,8 +1,8 @@

 /* pngread.c - read a PNG file
 *
- * Last changed in libpng 1.5.19 [August 21, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.23 [July 23, 2015]
+ * Copyright (c) 1998-2015 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.)
 *
@@ -559,7 +559,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
      if (ret == Z_STREAM_END)
      {
         if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
-            png_ptr->idat_size)
+             png_ptr->idat_size)
            png_benign_error(png_ptr, "Extra compressed data");
         png_ptr->mode |= PNG_AFTER_IDAT;
         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
@@ -617,7 +617,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 #ifdef PNG_READ_INTERLACING_SUPPORTED
   /* Blow up interlaced rows to full size */
   if (png_ptr->interlaced &&
-      (png_ptr->transformations & PNG_INTERLACE))
+       (png_ptr->transformations & PNG_INTERLACE))
   {
      if (png_ptr->pass < 6)
         png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
@@ -1119,9 +1119,8 @@ png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 #ifdef PNG_INFO_IMAGE_SUPPORTED
 void PNGAPI
-png_read_png(png_structp png_ptr, png_infop info_ptr,
-                           int transforms,
-                           voidp params)
+png_read_png(png_structp png_ptr, png_infop info_ptr, int transforms,
+    voidp params)
 {
   int row;

@@ -1281,7 +1280,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,

      for (row = 0; row < (int)info_ptr->height; row++)
         info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
-            png_get_rowbytes(png_ptr, info_ptr));
+             png_get_rowbytes(png_ptr, info_ptr));
   }

   png_read_image(png_ptr, info_ptr->row_pointers);
--- a/pngset.c
+++ b/pngset.c
@@ -1,7 +1,7 @@

 /* pngset.c - storage of image information into info struct
 *
- * Last changed in libpng 1.5.22 [March 26, 2015]
+ * Last changed in libpng 1.5.23 [July 23, 2015]
 * Copyright (c) 1998-2015 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.)
@@ -673,7 +673,7 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr,
   int i;
   size_t element_size;

-   png_debug1(1, "in %lx storage function", png_ptr == NULL ? "unexpected" :
+  png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11 :
      (unsigned long)png_ptr->chunk_name);

   if (png_ptr == NULL || info_ptr == NULL || num_text == 0)
--- a/pngstruct.h
+++ b/pngstruct.h
@@ -1,8 +1,8 @@

 /* pngstruct.h - header file for PNG reference library
 *
- * Last changed in libpng 1.5.15 [March 28, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.23 [July 23, 2015]
+ * Copyright (c) 1998-2015 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.)
 *
@@ -236,16 +236,6 @@ struct png_struct_def
   png_uint_16p hist;                /* histogram */
 #endif

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   png_byte heuristic_method;        /* heuristic for row filter selection */
-   png_byte num_prev_filters;        /* number of weights for previous rows */
-   png_bytep prev_filters;           /* filter type(s) of previous row(s) */
-   png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
-   png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
-   png_uint_16p filter_costs;        /* relative filter calculation cost */
-   png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
-#endif
-
 #ifdef PNG_TIME_RFC1123_SUPPORTED
   /* This is going to be unused in libpng16 and removed from libpng17 */
   char time_buffer[29]; /* String to hold RFC 1123 time text */
--- a/pngtest.c
+++ b/pngtest.c
@@ -564,6 +564,7 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
   }

   /* Unlink the element from the list. */
+   if (pinformation != NULL)
   {
      memory_infop *ppinfo = &pinformation;

@@ -580,8 +581,7 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
            /* We must free the list element too, but first kill
               the memory that is to be freed. */
            memset(ptr, 0x55, pinfo->size);
-            if (pinfo != NULL)
-               free(pinfo);
+            free(pinfo);
            pinfo = NULL;
            break;
         }
@@ -1463,8 +1463,9 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
         png_set_tIME(write_ptr, write_end_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
         /* We have to use memcpy instead of "=" because the string
-            pointed to by png_convert_to_rfc1123() gets free'ed before
-            we use it */
+          * pointed to by png_convert_to_rfc1123() gets free'ed before
+          * we use it.
+          */
         memcpy(tIME_string,
                png_convert_to_rfc1123(read_ptr, mod_time),
                png_sizeof(tIME_string));
@@ -2024,4 +2025,4 @@ main(void)
 #endif

 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_5_22 Your_png_h_is_not_version_1_5_22;
+typedef png_libpng_version_1_5_23 Your_png_h_is_not_version_1_5_23;
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -1,8 +1,8 @@

 /* pngwrite.c - general routines to write a PNG file
 *
- * Last changed in libpng 1.5.15 [March 28, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.23 [July 23, 2015]
+ * Copyright (c) 1998-2015 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.)
 *
@@ -34,85 +34,87 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)

   if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
   {
-   /* Write PNG signature */
-   png_write_sig(png_ptr);
+      /* Write PNG signature */
+      png_write_sig(png_ptr);

 #ifdef PNG_MNG_FEATURES_SUPPORTED
-   if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
-       (png_ptr->mng_features_permitted))
-   {
-      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
-      png_ptr->mng_features_permitted = 0;
-   }
+      if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
+          (png_ptr->mng_features_permitted))
+      {
+         png_warning(png_ptr,
+             "MNG features are not allowed in a PNG datastream");
+         png_ptr->mng_features_permitted = 0;
+      }
 #endif

-   /* Write IHDR information. */
-   png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
-       info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
-       info_ptr->filter_type,
+      /* Write IHDR information. */
+      png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
+          info_ptr->bit_depth, info_ptr->color_type,
+          info_ptr->compression_type, info_ptr->filter_type,
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
-       info_ptr->interlace_type);
+          info_ptr->interlace_type
 #else
-       0);
+          0
 #endif
-   /* The rest of these check to see if the valid field has the appropriate
-    * flag set, and if it does, writes the chunk.
-    */
+          );
+      /* The rest of these check to see if the valid field has the appropriate
+       * flag set, and if it does, writes the chunk.
+       */
 #ifdef PNG_WRITE_gAMA_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_gAMA)
-      png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
+      if (info_ptr->valid & PNG_INFO_gAMA)
+         png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
 #endif
 #ifdef PNG_WRITE_sRGB_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_sRGB)
-      png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
+      if (info_ptr->valid & PNG_INFO_sRGB)
+         png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
 #endif

 #ifdef PNG_WRITE_iCCP_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_iCCP)
-      png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
-          (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
+      if (info_ptr->valid & PNG_INFO_iCCP)
+         png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
+             (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
 #endif
 #ifdef PNG_WRITE_sBIT_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_sBIT)
-      png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
+      if (info_ptr->valid & PNG_INFO_sBIT)
+         png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
 #endif
 #ifdef PNG_WRITE_cHRM_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_cHRM)
-      png_write_cHRM_fixed(png_ptr,
-          info_ptr->x_white, info_ptr->y_white,
-          info_ptr->x_red, info_ptr->y_red,
-          info_ptr->x_green, info_ptr->y_green,
-          info_ptr->x_blue, info_ptr->y_blue);
+      if (info_ptr->valid & PNG_INFO_cHRM)
+         png_write_cHRM_fixed(png_ptr,
+             info_ptr->x_white, info_ptr->y_white,
+             info_ptr->x_red, info_ptr->y_red,
+             info_ptr->x_green, info_ptr->y_green,
+             info_ptr->x_blue, info_ptr->y_blue);
 #endif

 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   if (info_ptr->unknown_chunks_num)
-   {
-      png_unknown_chunk *up;
-
-      png_debug(5, "writing extra chunks");
-
-      for (up = info_ptr->unknown_chunks;
-           up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
-           up++)
+      if (info_ptr->unknown_chunks_num)
      {
-         int keep = png_handle_as_unknown(png_ptr, up->name);
+         png_unknown_chunk *up;

-         if (keep != PNG_HANDLE_CHUNK_NEVER &&
-             up->location &&
-             !(up->location & PNG_HAVE_PLTE) &&
-             !(up->location & PNG_HAVE_IDAT) &&
-             !(up->location & PNG_AFTER_IDAT) &&
-             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
-             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+         png_debug(5, "writing extra chunks");
+
+         for (up = info_ptr->unknown_chunks;
+              up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+              up++)
         {
-            if (up->size == 0)
-               png_warning(png_ptr, "Writing zero-length unknown chunk");
+            int keep = png_handle_as_unknown(png_ptr, up->name);

-            png_write_chunk(png_ptr, up->name, up->data, up->size);
+            if (keep != PNG_HANDLE_CHUNK_NEVER &&
+                up->location &&
+                !(up->location & PNG_HAVE_PLTE) &&
+                !(up->location & PNG_HAVE_IDAT) &&
+                !(up->location & PNG_AFTER_IDAT) &&
+                ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
+                (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+            {
+               if (up->size == 0)
+                  png_warning(png_ptr, "Writing zero-length unknown chunk");
+
+               png_write_chunk(png_ptr, up->name, up->data, up->size);
+            }
         }
      }
-   }
 #endif
      png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
   }
@@ -457,11 +459,6 @@ png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
       warn_fn, NULL, NULL, NULL));
 }

-/* Alternate initialize png_ptr structure, and allocate any memory needed */
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-static void png_reset_filter_heuristics(png_structp png_ptr); /* forward decl */
-#endif
-
 PNG_FUNCTION(png_structp,PNGAPI
 png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
@@ -503,14 +500,13 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 */
 #ifdef USE_FAR_KEYWORD
   if (setjmp(tmp_jmpbuf))
+      png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
+   PNG_ABORT();
 #else
   if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
-#endif
-#ifdef USE_FAR_KEYWORD
-   png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
-#endif
      PNG_ABORT();
 #endif
+#endif

 #ifdef PNG_USER_MEM_SUPPORTED
   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
@@ -547,10 +543,6 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,

   png_set_write_fn(png_ptr, NULL, NULL, NULL);

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   png_reset_filter_heuristics(png_ptr);
-#endif
-
   return (png_ptr);
 }

@@ -985,13 +977,6 @@ png_write_destroy(png_structp png_ptr)
   png_free(png_ptr, png_ptr->paeth_row);
 #endif

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   /* Use this to save a little code space, it doesn't free the filter_costs */
-   png_reset_filter_heuristics(png_ptr);
-   png_free(png_ptr, png_ptr->filter_costs);
-   png_free(png_ptr, png_ptr->inv_filter_costs);
-#endif
-
 #ifdef PNG_SETJMP_SUPPORTED
   /* Reset structure */
   png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
@@ -1082,6 +1067,7 @@ png_set_filter(png_structp png_ptr, int method, int filters)
       */
      if (png_ptr->row_buf != NULL)
      {
+         png_ptr->do_filter = PNG_FILTER_NONE;
 #ifdef PNG_WRITE_FILTER_SUPPORTED
         if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
         {
@@ -1142,8 +1128,8 @@ png_set_filter(png_structp png_ptr, int method, int filters)
         }

         if (png_ptr->do_filter == PNG_NO_FILTERS)
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
            png_ptr->do_filter = PNG_FILTER_NONE;
+#endif /* PNG_WRITE_FILTER_SUPPORTED */
      }
   }
   else
@@ -1157,122 +1143,7 @@ png_set_filter(png_structp png_ptr, int method, int filters)
 * filtered data going to zlib more consistent, hopefully resulting in
 * better compression.
 */
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED      /* GRR 970116 */
-/* Convenience reset API. */
-static void
-png_reset_filter_heuristics(png_structp png_ptr)
-{
-   /* Clear out any old values in the 'weights' - this must be done because if
-    * the app calls set_filter_heuristics multiple times with different
-    * 'num_weights' values we would otherwise potentially have wrong sized
-    * arrays.
-    */
-   png_ptr->num_prev_filters = 0;
-   png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
-   if (png_ptr->prev_filters != NULL)
-   {
-      png_bytep old = png_ptr->prev_filters;
-      png_ptr->prev_filters = NULL;
-      png_free(png_ptr, old);
-   }
-   if (png_ptr->filter_weights != NULL)
-   {
-      png_uint_16p old = png_ptr->filter_weights;
-      png_ptr->filter_weights = NULL;
-      png_free(png_ptr, old);
-   }
-
-   if (png_ptr->inv_filter_weights != NULL)
-   {
-      png_uint_16p old = png_ptr->inv_filter_weights;
-      png_ptr->inv_filter_weights = NULL;
-      png_free(png_ptr, old);
-   }
-
-   /* Leave the filter_costs - this array is fixed size. */
-}
-
-static int
-png_init_filter_heuristics(png_structp png_ptr, int heuristic_method,
-   int num_weights)
-{
-   if (png_ptr == NULL)
-      return 0;
-
-   /* Clear out the arrays */
-   png_reset_filter_heuristics(png_ptr);
-
-   /* Check arguments; the 'reset' function makes the correct settings for the
-    * unweighted case, but we must handle the weight case by initializing the
-    * arrays for the caller.
-    */
-   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-   {
-      int i;
-
-      if (num_weights > 0)
-      {
-         png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_byte) * num_weights));
-
-         /* To make sure that the weighting starts out fairly */
-         for (i = 0; i < num_weights; i++)
-         {
-            png_ptr->prev_filters[i] = 255;
-         }
-
-         png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
-
-         png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
-
-         for (i = 0; i < num_weights; i++)
-         {
-            png_ptr->inv_filter_weights[i] =
-            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
-         }
-
-         /* Safe to set this now */
-         png_ptr->num_prev_filters = (png_byte)num_weights;
-      }
-
-      /* If, in the future, there are other filter methods, this would
-       * need to be based on png_ptr->filter.
-       */
-      if (png_ptr->filter_costs == NULL)
-      {
-         png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
-
-         png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
-             (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
-      }
-
-      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
-      {
-         png_ptr->inv_filter_costs[i] =
-         png_ptr->filter_costs[i] = PNG_COST_FACTOR;
-      }
-
-      /* All the arrays are inited, safe to set this: */
-      png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED;
-
-      /* Return the 'ok' code. */
-      return 1;
-   }
-   else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT ||
-      heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
-   {
-      return 1;
-   }
-   else
-   {
-      png_warning(png_ptr, "Unknown filter heuristic method");
-      return 0;
-   }
-}
-
+#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
 /* Provide floating and fixed point APIs */
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 void PNGAPI
@@ -1280,52 +1151,11 @@ png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
    int num_weights, png_const_doublep filter_weights,
    png_const_doublep filter_costs)
 {
-   png_debug(1, "in png_set_filter_heuristics");
-
-   /* The internal API allocates all the arrays and ensures that the elements of
-    * those arrays are set to the default value.
-    */
-   if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
-      return;
-
-   /* If using the weighted method copy in the weights. */
-   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-   {
-      int i;
-      for (i = 0; i < num_weights; i++)
-      {
-         if (filter_weights[i] <= 0.0)
-         {
-            png_ptr->inv_filter_weights[i] =
-            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
-         }
-
-         else
-         {
-            png_ptr->inv_filter_weights[i] =
-                (png_uint_16)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5);
-
-            png_ptr->filter_weights[i] =
-                (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5);
-         }
-      }
-
-      /* Here is where we set the relative costs of the different filters.  We
-       * should take the desired compression level into account when setting
-       * the costs, so that Paeth, for instance, has a high relative cost at low
-       * compression levels, while it has a lower relative cost at higher
-       * compression settings.  The filter types are in order of increasing
-       * relative cost, so it would be possible to do this with an algorithm.
-       */
-      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) if (filter_costs[i] >= 1.0)
-      {
-         png_ptr->inv_filter_costs[i] =
-             (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5);
-
-         png_ptr->filter_costs[i] =
-             (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5);
-      }
-   }
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(heuristic_method)
+   PNG_UNUSED(num_weights)
+   PNG_UNUSED(filter_weights)
+   PNG_UNUSED(filter_costs)
 }
 #endif /* FLOATING_POINT */

@@ -1335,66 +1165,14 @@ png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method,
    int num_weights, png_const_fixed_point_p filter_weights,
    png_const_fixed_point_p filter_costs)
 {
-   png_debug(1, "in png_set_filter_heuristics_fixed");
-
-   /* The internal API allocates all the arrays and ensures that the elements of
-    * those arrays are set to the default value.
-    */
-   if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
-      return;
-
-   /* If using the weighted method copy in the weights. */
-   if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-   {
-      int i;
-      for (i = 0; i < num_weights; i++)
-      {
-         if (filter_weights[i] <= 0)
-         {
-            png_ptr->inv_filter_weights[i] =
-            png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
-         }
-
-         else
-         {
-            png_ptr->inv_filter_weights[i] = (png_uint_16)
-               ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1);
-
-            png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR*
-               PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]);
-         }
-      }
-
-      /* Here is where we set the relative costs of the different filters.  We
-       * should take the desired compression level into account when setting
-       * the costs, so that Paeth, for instance, has a high relative cost at low
-       * compression levels, while it has a lower relative cost at higher
-       * compression settings.  The filter types are in order of increasing
-       * relative cost, so it would be possible to do this with an algorithm.
-       */
-      for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
-         if (filter_costs[i] >= PNG_FP_1)
-      {
-         png_uint_32 tmp;
-
-         /* Use a 32 bit unsigned temporary here because otherwise the
-          * intermediate value will be a 32 bit *signed* integer (ANSI rules)
-          * and this will get the wrong answer on division.
-          */
-         tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2);
-         tmp /= filter_costs[i];
-
-         png_ptr->inv_filter_costs[i] = (png_uint_16)tmp;
-
-         tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF;
-         tmp /= PNG_FP_1;
-
-         png_ptr->filter_costs[i] = (png_uint_16)tmp;
-      }
-   }
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(heuristic_method)
+   PNG_UNUSED(num_weights)
+   PNG_UNUSED(filter_weights)
+   PNG_UNUSED(filter_costs)
 }
 #endif /* FIXED_POINT */
-#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+#endif /* WRITE_WEIGHTED_FILTER */

 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
 void PNGAPI
@@ -1533,10 +1311,10 @@ png_set_text_compression_window_bits(png_structp png_ptr, int window_bits)
 #ifndef WBITS_8_OK
   /* Avoid libpng bug with 256-byte windows */
   if (window_bits == 8)
-      {
-        png_warning(png_ptr, "Text compression window is being reset to 512");
-        window_bits = 9;
-      }
+   {
+      png_warning(png_ptr, "Text compression window is being reset to 512");
+      window_bits = 9;
+   }

 #endif
   png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS;
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -1,8 +1,8 @@

 /* pngwutil.c - utilities to write a PNG file
 *
- * Last changed in libpng 1.5.19 [August 21, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.5.23 [July 23, 2015]
+ * Copyright (c) 1998-2015 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.)
 *
@@ -2429,20 +2429,9 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
   png_uint_32 mins, bpp;
   png_byte filter_to_do = png_ptr->do_filter;
   png_size_t row_bytes = row_info->rowbytes;
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   int num_p_filters = png_ptr->num_prev_filters;
-#endif

   png_debug(1, "in png_write_find_filter");

-#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-  if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
-  {
-     /* These will never be selected so we need not test them. */
-     filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
-  }
-#endif
-
   /* Find out how many bytes offset each pixel is */
   bpp = (row_info->pixel_depth + 7) >> 3;

@@ -2494,44 +2483,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
         sum += (v < 128) ? v : 256 - v;
      }

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         png_uint_32 sumhi, sumlo;
-         int j;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
-
-         /* Reduce the sum if we match any of the previous rows */
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
-            {
-               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         /* Factor in the cost of this filter (this is here for completeness,
-          * but it makes no sense to have a "cost" for the NONE filter, as
-          * it has the minimum possible computational cost - none).
-          */
-         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
-             PNG_COST_SHIFT;
-
-         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
-             PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
      mins = sum;
   }

@@ -2564,44 +2515,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
      png_size_t i;
      int v;

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      /* We temporarily increase the "minimum sum" by the factor we
-       * would reduce the sum of this filter, so that we can do the
-       * early exit comparison without scaling the sum each time.
-       */
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-             PNG_COST_SHIFT;
-
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-             PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
-#endif
-
      for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
           i++, rp++, dp++)
      {
@@ -2621,40 +2534,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
            break;
      }

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 sumhi, sumlo;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
-            {
-               sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-             PNG_COST_SHIFT;
-
-         sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-             PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
-
      if (sum < mins)
      {
         mins = sum;
@@ -2685,41 +2564,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
      png_size_t i;
      int v;

-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
-             PNG_COST_SHIFT;
-
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
-             PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
-#endif
-
      for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
          pp = prev_row + 1; i < row_bytes; i++)
      {
@@ -2731,40 +2575,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
            break;
      }

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 sumhi, sumlo;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
-            {
-               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
-             PNG_COST_SHIFT;
-
-         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
-             PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
-
      if (sum < mins)
      {
         mins = sum;
@@ -2799,40 +2609,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
      png_size_t i;
      int v;

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
-             PNG_COST_SHIFT;
-
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
-             PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
-#endif
-
      for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
           pp = prev_row + 1; i < bpp; i++)
      {
@@ -2852,40 +2628,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
            break;
      }

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 sumhi, sumlo;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
-            {
-               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
-             PNG_COST_SHIFT;
-
-         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
-             PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
-
      if (sum < mins)
      {
         mins = sum;
@@ -2940,40 +2682,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
      png_size_t i;
      int v;

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-             PNG_COST_SHIFT;
-
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-             PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
-#endif
-
      for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
          pp = prev_row + 1; i < bpp; i++)
      {
@@ -3027,40 +2735,6 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
            break;
      }

-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 sumhi, sumlo;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
-            {
-               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-
-               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
-                   PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-             PNG_COST_SHIFT;
-
-         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-             PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
-
      if (sum < mins)
      {
         best_row = png_ptr->paeth_row;
@@ -3070,26 +2744,8 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)

   /* Do the actual writing of the filtered row data from the chosen filter. */
   png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
-
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   /* Save the type of filter we picked this time for future calculations */
-   if (png_ptr->num_prev_filters > 0)
-   {
-      int j;
-
-      for (j = 1; j < num_p_filters; j++)
-      {
-         png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
-      }
-
-      png_ptr->prev_filters[j] = best_row[0];
-   }
-#endif
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
 }

-
 /* Do the actual writing of a previously filtered row. */
 static void
 png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row,
--- a/projects/vstudio/readme.txt
+++ b/projects/vstudio/readme.txt
@@ -1,7 +1,7 @@

 VisualStudio instructions

-libpng version 1.5.22 - March 26, 2015
+libpng version 1.5.23 - July 23, 2015

 Copyright (c) 1998-2010 Glenn Randers-Pehrson

--- a/projects/vstudio/zlib.props
+++ b/projects/vstudio/zlib.props
@@ -2,7 +2,7 @@
 <!--
 * zlib.props - location of zlib source
 *
- * libpng version 1.5.22 - March 26, 2015
+ * libpng version 1.5.23 - July 23, 2015
 *
 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
 *
--- a/scripts/README.txt
+++ b/scripts/README.txt
@@ -1,9 +1,9 @@

-Makefiles for  libpng version 1.5.22 - March 26, 2015
+Makefiles for  libpng version 1.5.23 - July 23, 2015

 pnglibconf.h.prebuilt       =>  Stores configuration settings
 makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng15.so.15.1.5.22)
+                       (gcc, creates libpng15.so.15.1.5.23)
 makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
 makefile.knr      =>  Archaic UNIX Makefile that converts files with
                       ansi2knr (Requires ansi2knr.c from
@@ -34,12 +34,12 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
 makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
 makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
 makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng15.so.15.1.5.22)
+                       creates libpng15.so.15.1.5.23)
 makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
 makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng15.so.15.1.5.22)
+                       creates libpng15.so.15.1.5.23)
 makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng15.so.15.1.5.22)
+                       creates libpng15.so.15.1.5.23)
 makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
 makefile.sunos    =>  Sun makefile
 makefile.32sunu   =>  Sun Ultra 32-bit makefile
--- a/scripts/def.c
+++ b/scripts/def.c
@@ -21,7 +21,7 @@ PNG_DFN "OS2 DESCRIPTION "PNG image compression library""
 PNG_DFN "OS2 CODE PRELOAD MOVEABLE DISCARDABLE"
 PNG_DFN ""
 PNG_DFN "EXPORTS"
-PNG_DFN ";Version 1.5.22"
+PNG_DFN ";Version 1.5.23"

 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\
        PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"
--- a/scripts/libpng-config-head.in
+++ b/scripts/libpng-config-head.in
@@ -11,7 +11,7 @@

 # Modeled after libxml-config.

-version=1.5.22
+version=1.5.23
 prefix=""
 libdir=""
 libs=""
--- a/scripts/libpng.pc.in
+++ b/scripts/libpng.pc.in
@@ -5,6 +5,6 @@ includedir=@includedir@/libpng15

 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.5.22
+Version: 1.5.23
 Libs: -L${libdir} -lpng15
 Cflags: -I${includedir}
--- a/scripts/makefile.cegcc
+++ b/scripts/makefile.cegcc
@@ -23,7 +23,7 @@

 VERMAJ = 1
 VERMIN = 5
-VERMIC = 22
+VERMIC = 23
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)
--- a/scripts/makefile.linux
+++ b/scripts/makefile.linux
@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng15
 PNGMAJ = 15
-RELEASE = 22
+RELEASE = 23

 # Shared library names:
 LIBSO=$(LIBNAME).so
--- a/scripts/makefile.msys
+++ b/scripts/makefile.msys
@@ -18,7 +18,7 @@ exec_prefix=$(prefix)
 # Library name:
 LIBNAME = libpng15
 PNGMAJ = 15
-RELEASE = 22
+RELEASE = 23

 # Shared library names:
 LIBSO=$(LIBNAME).dll
--- a/scripts/makefile.ne12bsd
+++ b/scripts/makefile.ne12bsd
@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng15

 LIB=	png15
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.5.22
+SHLIB_MINOR=	1.5.23
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
--- a/scripts/makefile.netbsd
+++ b/scripts/makefile.netbsd
@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include

 LIB=	png
 SHLIB_MAJOR=	15
-SHLIB_MINOR=	1.5.22
+SHLIB_MINOR=	1.5.23
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
--- a/scripts/makefile.openbsd
+++ b/scripts/makefile.openbsd
@@ -11,7 +11,7 @@ LIBDIR=	${PREFIX}/lib
 MANDIR= ${PREFIX}/man/cat

 SHLIB_MAJOR=	15
-SHLIB_MINOR=	1.5.22
+SHLIB_MINOR=	1.5.23

 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -1,7 +1,7 @@
-/* 1.5.22 STANDARD API DEFINITION */
+/* 1.5.23 STANDARD API DEFINITION */
 /* pnglibconf.h - library build configuration */

-/* libpng version 1.5.22 - March 26, 2015 */
+/* libpng version 1.5.23 - July 23, 2015 */

 /* Copyright (c) 1998-2013 Glenn Randers-Pehrson */

@@ -95,8 +95,6 @@
 #define PNG_SAVE_INT_32_SUPPORTED
 #define PNG_SEQUENTIAL_READ_SUPPORTED
 #define PNG_SETJMP_SUPPORTED
-#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
-#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
 /*#undef PNG_SET_OPTION_SUPPORTED*/
 #define PNG_SET_USER_LIMITS_SUPPORTED
 #define PNG_STDIO_SUPPORTED
--- a/scripts/symbols.def
+++ b/scripts/symbols.def
@@ -1,4 +1,4 @@
-;Version 1.5.22
+;Version 1.5.23
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng
Author	SHA1	Message	Date
Glenn Randers-Pehrson	a058d6cee0	[libpng15] Imported from libpng-1.5.23.tar	2015-07-22 22:40:33 -05:00
Glenn Randers-Pehrson	445ad8fabf	[libpng15] Imported from libpng-1.5.23rc03.tar	2015-07-15 21:23:58 -05:00
Glenn Randers-Pehrson	4dc8ea0929	[libpng15] Removed WEIGHTED_FILTER paragraph from the man page.	2015-07-13 14:42:14 -05:00
Glenn Randers-Pehrson	91c2de79b9	[libpng15] Bump version to libpng-1.5.23rc03.tar	2015-07-13 08:30:27 -05:00
Glenn Randers-Pehrson	06bf45e527	[libpng15] Imported from libpng-1.5.23rc02.tar	2015-07-13 07:06:07 -05:00
Glenn Randers-Pehrson	ce12446903	[libpng15] Restored unused FILTER_HEURISTIC macros removed at libpng-1.5.23beta02 to png.h to avoid compatibility warnings.	2015-07-13 07:04:17 -05:00
Glenn Randers-Pehrson	ceaf50079a	[libpng15] Imported from libpng-1.5.23rc01.tar	2015-07-09 11:58:09 -05:00
Glenn Randers-Pehrson	5129cbb795	[libpng15] Belatedly added Mans Rullgard to the list of Contributing Authors.	2015-07-09 11:53:58 -05:00
Glenn Randers-Pehrson	5c88d90ce8	[libpng15] Bump version to 1.5.23beta03	2015-06-30 11:01:58 -05:00
Glenn Randers-Pehrson	57b246e736	[libpng15] Imported from libpng-1.5.23beta02.tar	2015-06-30 11:01:50 -05:00
Glenn Randers-Pehrson	32751e6a20	[libpng15] Removed some unused WEIGHTED_FILTER macros from png.h and pngstruct.h	2015-06-10 07:14:50 -05:00
Glenn Randers-Pehrson	d522ff063f	[libpng15] Removed non-working progressive reader 'skip' function.	2015-06-03 17:09:47 -05:00
Glenn Randers-Pehrson	ab096c961b	[libpng15] Quieted Coverity issues in pngvalid.c.	2015-06-03 16:18:23 -05:00
Glenn Randers-Pehrson	5ce5cb7a9a	[libpng15] Bump version to 1.5.23beta02	2015-06-01 21:10:37 -05:00
Glenn Randers-Pehrson	8ed373b1fa	[libpng15] Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the compiled library size. It never worked properly and as far as we can tell, no one uses it. The png_set_filter_heuristics() and png_set_filter_heuristics_fixed() APIs are retained but deprecated and do nothing.	2015-06-01 21:08:14 -05:00
Glenn Randers-Pehrson	9fee864806	[libpng15] Imported from libpng-1.5.23beta01.tar	2015-06-01 21:07:27 -05:00
Glenn Randers-Pehrson	2cd7404743	[libpng15] Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug report from Christopher Ferris).	2015-05-21 15:20:52 -05:00
Glenn Randers-Pehrson	8583cc23e4	[libpng15] Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds.	2015-05-09 21:44:18 -05:00
Glenn Randers-Pehrson	58a54220dd	[libpng15] Replaced "unexpected" with an integer in pngset.c where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.	2015-04-29 11:53:28 -05:00
Glenn Randers-Pehrson	e985b95d65	[libpng15] Removed unused PNG_SET_CHUNK_[CACHE\|MALLOC]_LIMIT_SUPPORTED definitions from pnglibconf.h.prebuilt (Andrew Church).	2015-03-27 09:14:25 -05:00
Glenn Randers-Pehrson	4925a28f6d	[libpng15] Bump version to 1.5.23beta01	2015-03-27 09:09:21 -05:00