[master] Imported from libpng-1.6.24.tar

2025-07-10 18:04:09 +02:00 · 2016-08-03 21:16:26 -05:00 · 2016-08-03 21:16:26 -05:00 · 0c29ab2b31
commit 0c29ab2b31
parent 5a8b04137f
67 changed files with 4131 additions and 1252 deletions
--- a/90
+++ b/90
@ -1,4 +1,4 @@
-Libpng 1.6.23 - June 9, 2016
+Libpng 1.6.24 - August 4, 2016
 This is a public release of libpng, intended for use in production codes.
@ -7,38 +7,78 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
-   libpng-1.6.23.tar.xz (LZMA-compressed, recommended)
+   libpng-1.6.24.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.23.tar.gz
+   libpng-1.6.24.tar.gz
 Source files with CRLF line endings (for Windows), without the
 "configure" script
-   lpng1623.7z  (LZMA-compressed, recommended)
+   lpng1624.7z  (LZMA-compressed, recommended)
-   lpng1623.zip
+   lpng1624.zip
 Other information:
-   libpng-1.6.23-README.txt
+   libpng-1.6.24-README.txt
-   libpng-1.6.23-LICENSE.txt
+   libpng-1.6.24-LICENSE.txt
-   libpng-1.6.23-*.asc (armored detached GPG signatures)
+   libpng-1.6.24-*.asc (armored detached GPG signatures)
-Changes since the last public release (1.6.22):
+Changes since the last public release (1.6.23):
-
+  Avoid potential overflow of the PNG_IMAGE_SIZE macro.  This macro
-  Stop a potential memory leak in png_set_tRNS() (Bug report by Ted Ying).
+    is not used within libpng, but is used in some of the examples.
-  Fixed the progressive reader to handle empty first IDAT chunk properly
+  Correct filter heuristic overflow handling. This was broken when the
-    (patch by Timothy Nikkel).  This bug was introduced in libpng-1.6.0 and
+    write filter code was moved out-of-line; if there is a single filter and
-    only affected the libpng16 branch.
+    the heuristic sum overflows the calculation of the filtered line is not
-  Added tests in pngvalid.c to check zero-length IDAT chunks in various
+    completed.  In versions prior to 1.6 the code was duplicated in-line
-    positions.  Fixed the sequential reader to handle these more robustly
+    and the check not performed, so the filter operation completed; however,
-    (John Bowler).
+    in the multi-filter case where the sum is performed the 'none' filter would
-  Corrected progressive read input buffer in pngvalid.c. The previous version
+    be selected if all the sums overflowed, even if it wasn't in the filter
-    the code invariably passed just one byte at a time to libpng.  The intent
+    list.  The fix to the first problem is simply to provide PNG_SIZE_MAX as
-    was to pass a random number of bytes in the range 0..511.
+    the current lmins sum value; this means the sum can never exceed it and
-  Moved sse2 prototype from pngpriv.h to contrib/intel/intel_sse.patch.
+    overflows silently.  A reasonable compiler that does choose to inline
-  Added missing ")" in pngerror.c (Matt Sarrett).
+    the code will simply eliminate the sum check.
-  Fixed undefined behavior in png_push_save_buffer(). Do not call
+  The fix to the second problem is to use high precision arithmetic (this is
-    memcpy() with a null source, even if count is zero (Leon Scroggins III).
+    implemented in 1.7), however a simple safe fix here is to chose the lowest
-  Fixed bad link to RFC2083 in png.5 (Nikola Forro).
+    numbered filter in the list from png_set_filter (this only works if the
    first problem is also fixed) (John Bowler).
  Use a more efficient absolute value calculation on SSE2 (Matthieu Darbois).
  Fixed the case where PNG_IMAGE_BUFFER_SIZE can overflow in the application
    as a result of the application using an increased 'row_stride'; previously
    png_image_finish_read only checked for overflow on the base calculation of
    components.  (I.e. it checked for overflow of a 32-bit number on the total
    number of pixel components in the output format, not the possibly padded row
    length and not the number of bytes, which for linear formats is twice the
    number of components.)
  MSVC does not like '-(unsigned)', so replaced it with 0U-(unsigned)
  MSVC does not like (uInt) = -(unsigned) (i.e. as an initializer), unless
    the conversion is explicitly invoked by a cast.
  Put the SKIP definition in the correct place. It needs to come after the
    png.h include (see all the other .c files in contrib/libtests) because it
    depends on PNG_LIBPNG_VER.
  Removed the three compile warning options from the individual project
    files into the zlib.props globals.  It increases the warning level from 4
    to All and adds a list of the warnings that need to be turned off.  This is
    semi-documentary; the intent is to tell libpng users which warnings have
    been examined and judged non-fixable at present.  The warning about
    structure padding is fixable, but it would be a signficant change (moving
    structure members around).
  Optimized absolute value calculation in filter selection, similar to
    code in the PAETH decoder in pngrutil.c. Build with PNG_USE_ABS to
    use this.
  Added pngcp to the build together with a pngcp.dfa configuration test.
  Added high resolution timing to pngcp.
  Added "Common linking failures" section to INSTALL.
  Relocated misplaced #endif in png.c sRGB profile checking.
  Fixed two Coverity issues in pngcp.c.
  Avoid filter-selection heuristic sum calculations in cases where only one
    filter is a candidate for selection. This trades off code size (added
    private png_setup_*_row_only() functions) for speed.
  Fixed some indentation to comply with our coding style.
  Added contrib/tools/reindent.
  Eliminated unnecessary tests of boolean png_isaligned() vs 0.
  Conditionally compile SSE2 headers in contrib/intel/intel_sse.patch
  Conditionally compile png_decompress_chunk().
  Conditionally compile ARM_NEON headers in pngpriv.h
  Updated contrib/intel/intel_sse.patch
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
--- a/79
+++ b/79
@ -5596,6 +5596,85 @@ Version 1.6.23rc02 [June 4, 2016]
 Version 1.6.23 [June 9, 2016]
  Fixed bad link to RFC2083 in png.5 (Nikola Forro).
 Version 1.6.24beta01 [June 11, 2016]
  Avoid potential overflow of the PNG_IMAGE_SIZE macro.  This macro
    is not used within libpng, but is used in some of the examples.
 Version 1.6.24beta02 [June 23, 2016]
  Correct filter heuristic overflow handling. This was broken when the
    write filter code was moved out-of-line; if there is a single filter and
    the heuristic sum overflows the calculation of the filtered line is not
    completed.  In versions prior to 1.6 the code was duplicated in-line
    and the check not performed, so the filter operation completed; however,
    in the multi-filter case where the sum is performed the 'none' filter would
    be selected if all the sums overflowed, even if it wasn't in the filter
    list.  The fix to the first problem is simply to provide PNG_SIZE_MAX as
    the current lmins sum value; this means the sum can never exceed it and
    overflows silently.  A reasonable compiler that does choose to inline
    the code will simply eliminate the sum check.
  The fix to the second problem is to use high precision arithmetic (this is
    implemented in 1.7), however a simple safe fix here is to chose the lowest
    numbered filter in the list from png_set_filter (this only works if the
    first problem is also fixed) (John Bowler).
  Use a more efficient absolute value calculation on SSE2 (Matthieu Darbois).
  Fixed the case where PNG_IMAGE_BUFFER_SIZE can overflow in the application
    as a result of the application using an increased 'row_stride'; previously
    png_image_finish_read only checked for overflow on the base calculation of
    components.  (I.e. it checked for overflow of a 32-bit number on the total
    number of pixel components in the output format, not the possibly padded row
    length and not the number of bytes, which for linear formats is twice the
    number of components.)
  MSVC does not like '-(unsigned)', so replaced it with 0U-(unsigned)
  MSVC does not like (uInt) = -(unsigned) (i.e. as an initializer), unless
    the conversion is explicitly invoked by a cast.
  Put the SKIP definition in the correct place. It needs to come after the
    png.h include (see all the other .c files in contrib/libtests) because it
    depends on PNG_LIBPNG_VER.
  Removed the three compile warning options from the individual project
    files into the zlib.props globals.  It increases the warning level from 4
    to All and adds a list of the warnings that need to be turned off.  This is
    semi-documentary; the intent is to tell libpng users which warnings have
    been examined and judged non-fixable at present.  The warning about
    structure padding is fixable, but it would be a signficant change (moving
    structure members around).
 Version 1.6.24beta03 [July 4, 2016]
  Optimized absolute value calculation in filter selection, similar to
    code in the PAETH decoder in pngrutil.c. Build with PNG_USE_ABS to
    use this.
  Added pngcp to the build together with a pngcp.dfa configuration test.
  Added high resolution timing to pngcp.
  Added "Common linking failures" section to INSTALL.
  Relocated misplaced #endif in png.c sRGB profile checking.
  Fixed two Coverity issues in pngcp.c.
 Version 1.6.24beta04 [July 8, 2016]
  Avoid filter-selection heuristic sum calculations in cases where only one
    filter is a candidate for selection. This trades off code size (added
    private png_setup_*_row_only() functions) for speed.
 Version 1.6.24beta05 [July 13, 2016]
  Fixed some indentation to comply with our coding style.
  Added contrib/tools/reindent.
 Version 1.6.24beta06 [July 18, 2016]
  Fixed more indentation to comply with our coding style.
  Eliminated unnecessary tests of boolean png_isaligned() vs 0.
 Version 1.6.24rc01 [July 25, 2016]
  No changes.
 Version 1.6.24rc02 [August 1, 2016]
  Conditionally compile SSE2 headers in contrib/intel/intel_sse.patch
  Conditionally compile png_decompress_chunk().
 Version 1.6.24rc03 [August 2, 2016]
  Conditionally compile ARM_NEON headers in pngpriv.h
  Updated contrib/intel/intel_sse.patch
 Version 1.6.24[August 4, 2016]
  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
@ -35,7 +35,7 @@ enable_testing()
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 23)
+set(PNGLIB_RELEASE 24)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
@ -696,7 +696,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
  set_target_properties(png PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.23
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.24
    VERSION 16.${PNGLIB_RELEASE}.0
    SOVERSION 16
    CLEAN_DIRECT_OUTPUT 1)
--- a/39
+++ b/39
@ -18,7 +18,8 @@ VIII. Configuring libpng for 16-bit platforms
 XIII. Removing unwanted object code
 XIV. Changes to the build and configuration of libpng in libpng-1.5.x
  XV. Setjmp/longjmp issues
- XVI. Other sources of information about libpng
+ XVI. Common linking failures
 XVII. Other sources of information about libpng
 I. Simple installation
@ -78,7 +79,7 @@ Or you can use one of the "projects" in the "projects" directory.
 Before installing libpng, you must first install zlib, if it
 is not already on your system.  zlib can usually be found
 wherever you got libpng; otherwise go to http://zlib.net.  You can place
-zlib in in the same directory as libpng or in another directory.
+zlib in the same directory as libpng or in another directory.
 If your system already has a preinstalled zlib you will still need
 to have access to the zlib.h and zconf.h include files that
@ -382,28 +383,20 @@ This requires setjmp/longjmp, so you must either build the library
 with PNG_SETJMP_SUPPORTED defined, or with PNG_SIMPLIFIED_READ_SUPPORTED
 and PNG_SIMPLIFIED_WRITE_SUPPORTED undefined.
-XVI. Other sources of information about libpng:
+XVI. Common linking failures
 If your application fails to find libpng or zlib entries while linking:
  Be sure "-lz" appears after "-lpng" on your linking command.
  Be sure you have built libpng, zlib, and your application for the
  same platform (e.g., 32-bit or 64-bit).
  If you are using the vstudio project, observe the WARNING in
  project/vstudio/README.txt.
 XVII. Other sources of information about libpng:
 Further information can be found in the README and libpng-manual.txt
 files, in the individual makefiles, in png.h, and the manual pages
 libpng.3 and png.5.
 Using the ./configure script -- 16 December 2002.
 =================================================
 The ./configure script should work compatibly with what scripts/makefile.*
 did, however there are some options you might need to add to configure
 explicitly, which previously was done semi-automatically (if you didn't edit
 scripts/makefile.* yourself, that is)
 CFLAGS="-Wall -O -funroll-loops \
 -malign-loops=2 -malign-functions=2" ./configure --prefix=/usr/include \
 --with-pkgconfigdir=/usr/lib/pkgconfig --includedir=/usr/include
 You can alternatively specify --includedir=/usr/include, /usr/local/include,
 /usr/include/libpng16, or whatever.
 If you find that the configure script is out-of-date or is not supporting
 your platform properly, try running autogen.sh to regenerate "configure",
 "Makefile.in", and the other configuration files. Then try configure again.
--- a/4
+++ b/4
@ -10,7 +10,7 @@ this sentence.
 This code is released under the libpng license.
-libpng versions 1.0.7, July 1, 2000 through 1.6.23, June 9, 2016 are
+libpng versions 1.0.7, July 1, 2000 through 1.6.24, August 4, 2016 are
 Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
@ -127,4 +127,4 @@ any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-June 9, 2016
+August 4, 2016
--- a/Makefile.am
+++ b/Makefile.am
@ -18,7 +18,7 @@ check_PROGRAMS += timepng
 endif
 # Utilities - installed
-bin_PROGRAMS= pngfix png-fix-itxt
+bin_PROGRAMS= pngcp pngfix png-fix-itxt
 # This ensures that pnglibconf.h gets built at the start of 'make all' or
 # 'make check', but it does not add dependencies to the individual programs,
@ -53,6 +53,9 @@ pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
 pngcp_SOURCES = contrib/tools/pngcp.c
 pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 # Generally these are single line shell scripts to run a test with a particular
 # set of parameters:
 TESTS =\
@ -230,6 +233,7 @@ contrib/libtests/timepng.o: pnglibconf.h
 contrib/tools/makesRGB.o: pnglibconf.h
 contrib/tools/pngfix.o: pnglibconf.h
 contrib/tools/pngcp.o: pnglibconf.h
 # We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
 # be built with PNG_USE_READ_MACROS; this prevents the read macros from
--- a/2
+++ b/2
@ -1,4 +1,4 @@
-README for libpng version 1.6.23 - June 9, 2016 (shared library 16.0)
+README for libpng version 1.6.24 - August 4, 2016 (shared library 16.0)
 See the note about version numbers near the top of png.h
 See INSTALL for instructions on how to install libpng.
--- a/1
+++ b/1
@ -11,7 +11,6 @@ Add "grayscale->palette" transformation and "palette->grayscale" detection.
 Improved dithering.
 Multi-lingual error and warning message support.
 Complete sRGB transformation (presently it simply uses gamma=0.45455).
 Make profile checking optional via a png_set_something() call.
 Man pages for function calls.
 Better documentation.
 Better filter selection
--- a/arm/arm_init.c
+++ b/arm/arm_init.c
@ -3,7 +3,7 @@
 *
 * Copyright (c) 2014,2016 Glenn Randers-Pehrson
 * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.22 [June 9, 2016]
+ * Last changed in libpng 1.6.22 [May 26, 2016]
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
--- a/arm/filter_neon_intrinsics.c
+++ b/arm/filter_neon_intrinsics.c
@ -5,7 +5,7 @@
 * Written by James Yu <james.yu at linaro.org>, October 2013.
 * Based on filter_neon.S, written by Mans Rullgard, 2011.
 *
- * Last changed in libpng 1.6.22 [June 9, 2016]
+ * Last changed in libpng 1.6.22 [May 26, 2016]
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
--- a/configure.ac
+++ b/configure.ac
@ -1,7 +1,7 @@
 # configure.ac
 # Copyright (c) 2004-2015 Glenn Randers-Pehrson
-# Last changed in libpng 1.6.22 [June 9, 2016]
+# Last changed in libpng 1.6.22 [May 26, 2016]
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@ -25,7 +25,7 @@ AC_PREREQ([2.68])
 dnl Version number stuff here:
-AC_INIT([libpng],[1.6.23],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.24],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 # libpng does not follow GNU file name conventions (hence 'foreign')
@ -36,7 +36,7 @@ AC_CONFIG_MACRO_DIR([scripts])
 # 1.13 is required for parallel tests
 AM_INIT_AUTOMAKE([1.13 foreign dist-xz color-tests silent-rules subdir-objects])
 # The following line causes --disable-maintainer-mode to be the default to
-# configure, this is necessary because libpng distributions cannot rely on the
+# configure. This is necessary because libpng distributions cannot rely on the
 # time stamps of the autotools generated files being correct
 AM_MAINTAINER_MODE
@ -46,10 +46,10 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
-PNGLIB_VERSION=1.6.23
+PNGLIB_VERSION=1.6.24
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=23
+PNGLIB_RELEASE=24
 dnl End of version number stuff
@ -67,7 +67,7 @@ AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
-dnl libtool/libtoolize; version 2.4.2 is the tested version, this or any
+dnl libtool/libtoolize; version 2.4.2 is the tested version. This or any
 dnl compatible later version may be used
 LT_INIT([win32-dll])
 LT_PREREQ([2.4.2])
--- a/contrib/conftest/pngcp.dfa
+++ b/contrib/conftest/pngcp.dfa
@ -0,0 +1,57 @@
 # pngcp.dfa
 #  Build time configuration of libpng
 #
 # Author: John Bowler
 # Copyright: (c) John Bowler, 2016
 # Usage rights:
 #  To the extent possible under law, the author has waived all copyright and
 #  related or neighboring rights to this work.  This work is published from:
 #  United States.
 #
 # Build libpng with support for pngcp.  This means just png_read_png,
 # png_write_png and small number of configuration settings.
 #
 everything = off
 # This option is specific to this configuration; it adds a #define to the
 # generated pnglibconf.h which turns on the (not portable) timing option for
 # pngcp.  Note that any option is automatically preceded by PNG_; there is no
 # way round this and this is deliberate.
 option PNGCP_TIMING
 # Because of the everything off above the option must also be turned on.  This
 # may not be done in one step because it is safer and avoids mis-spelled options
 # in user .dfa files to error out if an unrecognized option is turned on.
 option PNGCP_TIMING on
 # Options to turn on png_read_png and png_write_png:
 option INFO_IMAGE on
 option SEQUENTIAL_READ on
 option EASY_ACCESS on
 option WRITE on
 option WRITE_16BIT on
 option WRITE_FILTER on
 # pngcp needs this to preserve unknown chunks, switching all these on means that
 # pngcp can work without explicit known chunk reading suppport
 option UNKNOWN_CHUNKS on
 option SET_UNKNOWN_CHUNKS on
 option HANDLE_AS_UNKNOWN on
 option SAVE_UNKNOWN_CHUNKS on
 option WRITE_UNKNOWN_CHUNKS on
 # pngcp needs this to handle palette files with invalid indices:
 option CHECK_FOR_INVALID_INDEX on
 option GET_PALETTE_MAX on
 # Pre-libpng 1.7 pngcp has to stash text chunks manually, post 1.7 without this
 # text chunks should be handled as unknown ok.
 option TEXT on
 # this is used to turn off limits:
 option USER_LIMITS on
 option SET_USER_LIMITS on
 # these are are just required for specific customizations
 option WRITE_CUSTOMIZE_ZTXT_COMPRESSION on
 option WRITE_CUSTOMIZE_COMPRESSION on
--- a/contrib/intel/filter_sse2_intrinsics.c
+++ b/contrib/intel/filter_sse2_intrinsics.c
@ -6,7 +6,7 @@
 * Derived from arm/filter_neon_intrinsics.c, which was
 * Copyright (c) 2014,2016 Glenn Randers-Pehrson
 *
- * Last changed in libpng 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
@ -208,7 +208,7 @@ static __m128i abs_i16(__m128i x) {
   x = _mm_xor_si128(x, is_negative);
   /* +1 to negative lanes, else +0. */
-   x = _mm_add_epi16(x, _mm_srli_epi16(is_negative, 15));
+   x = _mm_sub_epi16(x, is_negative);
   return x;
 #endif
 }
--- a/contrib/intel/intel_sse.patch
+++ b/contrib/intel/intel_sse.patch
@ -55,7 +55,7 @@ diff --git a/configure.ac b/configure.ac
 diff --git a/Makefile.am b/Makefile.am
 --- a/Makefile.am	2016-05-17 18:15:12.000000000 -0400
 +++ b/Makefile.am	2016-05-25 19:48:10.631751170 -0400
-@@ -89,16 +89,20 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SO
+@@ -92,16 +92,20 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SO
 	pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c\
 	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
@ -77,8 +77,8 @@ diff --git a/Makefile.am b/Makefile.am
 #   Versioned symbols and restricted exports
 if HAVE_SOLARIS_LD
 diff --git a/pngpriv.h b/pngpriv.h
--- a/pngpriv.h	2016-05-31 09:20:34.442885047 -0500
+--- a/pngpriv.h	2016-08-01 18:13:38.770128810 -0500
-+++ b/pngpriv.h	2016-05-31 09:14:54.583492341 -0500
+++ b/pngpriv.h	2016-08-01 18:50:19.130179017 -0500
@@ -177,16 +177,52 @@
 #  endif /* !PNG_ARM_NEON_IMPLEMENTATION */
@ -132,7 +132,7 @@ diff --git a/pngpriv.h b/pngpriv.h
  * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
  * static library of libpng then link the DLL against that.
  */
-@@ -1184,16 +1220,29 @@ PNG_INTERNAL_FUNCTION(void,png_read_filt
+@@ -1185,16 +1221,31 @@ PNG_INTERNAL_FUNCTION(void,png_read_filt
     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop
     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
@ -140,7 +140,9 @@ diff --git a/pngpriv.h b/pngpriv.h
     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
     row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
- 
+ #endif
 + 
 +#if PNG_INTEL_SSE_IMPLEMENTATION > 0
 +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop
 +    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop
@ -153,7 +155,8 @@ diff --git a/pngpriv.h b/pngpriv.h
 +    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop
 +    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
-+
+#endif
 /* Choose the best filter to use and filter the row data */
 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
     png_row_infop row_info),PNG_EMPTY);
@ -161,18 +164,19 @@ diff --git a/pngpriv.h b/pngpriv.h
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr,
    png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY);
-    /* Read 'avail_out' bytes of data from the IDAT stream.  If the output buffer
+@@ -1914,16 +1965,20 @@ PNG_INTERNAL_FUNCTION(void, PNG_FILTER_O
@@ -1910,16 +1959,18 @@ PNG_INTERNAL_FUNCTION(void, PNG_FILTER_O
    /* Just declare the optimization that will be used */
 #else
    /* List *all* the possible optimizations here - this branch is required if
     * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
     * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
     */
 #  if PNG_ARM_NEON_OPT > 0
 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
    (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
 #  endif
 +#  if PNG_INTEL_SSE_IMPLEMENTATION > 0
 +PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_sse2,
 +   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
 +#  endif
 #endif
 PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
--- a/contrib/libtests/pngimage.c
+++ b/contrib/libtests/pngimage.c
@ -2,7 +2,7 @@
 *
 * Copyright (c) 2015,2016 John Cunningham Bowler
 *
- * Last changed in libpng 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
@ -45,8 +45,19 @@
 #  define SKIP 0
 #endif
-#if defined(PNG_INFO_IMAGE_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED)\
+#if PNG_LIBPNG_VER < 10700
-    && (defined(PNG_READ_PNG_SUPPORTED) || PNG_LIBPNG_VER < 10700)
+   /* READ_PNG and WRITE_PNG were not defined, so: */
 #  ifdef PNG_INFO_IMAGE_SUPPORTED
 #     ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 #        define PNG_READ_PNG_SUPPORTED
 #     endif /* SEQUENTIAL_READ */
 #     ifdef PNG_WRITE_SUPPORTED
 #        define PNG_WRITE_PNG_SUPPORTED
 #     endif /* WRITE */
 #  endif /* INFO_IMAGE */
 #endif /* pre 1.7.0 */
 #ifdef PNG_READ_PNG_SUPPORTED
 /* If a transform is valid on both read and write this implies that if the
 * transform is applied to read it must also be applied on write to produce
 * meaningful data.  This is because these transforms when performed on read
@ -395,7 +406,7 @@ buffer_destroy(struct buffer *buffer)
   buffer_destroy_list(list);
 }
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
 static void
 buffer_start_write(struct buffer *buffer)
 {
@ -565,7 +576,7 @@ struct display
   png_structp    read_pp;
   png_infop      read_ip;
-#  ifdef PNG_WRITE_SUPPORTED
+#  ifdef PNG_WRITE_PNG_SUPPORTED
      /* Used to write a new image (the original info_ptr is used) */
      png_structp   write_pp;
      struct buffer written_file;   /* where the file gets written */
@ -592,7 +603,7 @@ display_init(struct display *dp)
   dp->read_ip = NULL;
   buffer_init(&dp->original_file);
-#  ifdef PNG_WRITE_SUPPORTED
+#  ifdef PNG_WRITE_PNG_SUPPORTED
      dp->write_pp = NULL;
      buffer_init(&dp->written_file);
 #  endif
@ -605,7 +616,7 @@ display_clean_read(struct display *dp)
      png_destroy_read_struct(&dp->read_pp, &dp->read_ip, NULL);
 }
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
 static void
 display_clean_write(struct display *dp)
 {
@ -617,7 +628,7 @@ display_clean_write(struct display *dp)
 static void
 display_clean(struct display *dp)
 {
-#  ifdef PNG_WRITE_SUPPORTED
+#  ifdef PNG_WRITE_PNG_SUPPORTED
      display_clean_write(dp);
 #  endif
   display_clean_read(dp);
@ -635,7 +646,7 @@ static void
 display_destroy(struct display *dp)
 {
    /* Release any memory held in the display. */
-#  ifdef PNG_WRITE_SUPPORTED
+#  ifdef PNG_WRITE_PNG_SUPPORTED
      buffer_destroy(&dp->written_file);
 #  endif
@ -1082,6 +1093,7 @@ compare_read(struct display *dp, int applied_transforms)
      }
      else
 #     ifdef PNG_sBIT_SUPPORTED
      {
         unsigned long y;
         int bpp;   /* bits-per-pixel then bytes-per-pixel */
@ -1243,12 +1255,16 @@ compare_read(struct display *dp, int applied_transforms)
            }
         } /* for y */
      }
 #     else /* !sBIT */
         display_log(dp, INTERNAL_ERROR,
               "active shift transform but no sBIT support");
 #     endif /* !sBIT */
   }
   return 1; /* compare succeeded */
 }
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
 static void
 buffer_write(struct display *dp, struct buffer *buffer, png_bytep data,
   png_size_t size)
@ -1347,7 +1363,7 @@ write_png(struct display *dp, png_infop ip, int transforms)
    */
   display_clean_write(dp);
 }
-#endif /* WRITE_SUPPORTED */
+#endif /* WRITE_PNG */
 static int
 skip_transform(struct display *dp, int tr)
@ -1409,7 +1425,7 @@ test_one_file(struct display *dp, const char *filename)
         return; /* no point testing more */
   }
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
   /* Second test: write the original PNG data out to a new file (to test the
    * write side) then read the result back in and make sure that it hasn't
    * changed.
@ -1450,7 +1466,7 @@ test_one_file(struct display *dp, const char *filename)
          * out and read it back in again (without the reversible transforms)
          * we should get back to the place where we started.
          */
-#ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_PNG_SUPPORTED
         if ((current & write_transforms) == current)
         {
            /* All transforms reversible: write the PNG with the transformations
@ -1686,7 +1702,7 @@ main(const int argc, const char * const * const argv)
      return errors != 0;
   }
 }
-#else /* !INFO_IMAGE || !SEQUENTIAL_READ || !READ_PNG*/
+#else /* !READ_PNG */
 int
 main(void)
 {
--- a/contrib/libtests/pngstest.c
+++ b/contrib/libtests/pngstest.c
@ -3,7 +3,7 @@
 *
 * Copyright (c) 2013-2016 John Cunningham Bowler
 *
- * Last changed in libpng 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 *
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
@ -26,15 +26,6 @@
 #  include <config.h>
 #endif
 /* 1.6.1 added support for the configure test harness, which uses 77 to indicate
 * a skipped test, in earlier versions we need to succeed on a skipped test, so:
 */
 #if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
 #  define SKIP 77
 #else
 #  define SKIP 0
 #endif
 /* Define the following to use this test against your installed libpng, rather
 * than the one being built here:
 */
@ -44,6 +35,15 @@
 #  include "../../png.h"
 #endif
 /* 1.6.1 added support for the configure test harness, which uses 77 to indicate
 * a skipped test, in earlier versions we need to succeed on a skipped test, so:
 */
 #if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
 #  define SKIP 77
 #else
 #  define SKIP 0
 #endif
 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED /* Else nothing can be done */
 #include "../tools/sRGB.h"
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@ -1,7 +1,7 @@
 /* pngvalid.c - validate libpng by constructing then reading png files.
 *
- * Last changed in libpng 1.6.23 [June 9, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 * Copyright (c) 2014-2016 Glenn Randers-Pehrson
 * Written by John Cunningham Bowler
 *
@ -1589,7 +1589,7 @@ store_read_chunk(png_store *ps, png_bytep pb, const png_size_t max,
         {
            if (chunkpos < chunklen-4U)
            {
-               uInt avail = -1;
+               uInt avail = (uInt)-1;
               if (avail > (IDAT_len-4U) - IDAT_pos)
                  avail = (uInt)/*SAFE*/((IDAT_len-4U) - IDAT_pos);
--- a/contrib/tools/chkfmt
+++ b/contrib/tools/chkfmt
@ -1,4 +1,11 @@
 #!/bin/sh
 # chkfmt
 #
 # COPYRIGHT: Written by John Cunningham Bowler, 2010.
 # To the extent possible under law, the author has waived all copyright and
 # related or neighboring rights to this work.  This work is published from:
 # United States.
 #
 # Check the format of the source files in the current directory - checks for a
 # line length of 80 characters max and no tab characters.
--- a/contrib/tools/pngcp.c
+++ b/contrib/tools/pngcp.c
--- a/contrib/tools/reindent
+++ b/contrib/tools/reindent
@ -0,0 +1,25 @@
 #!/bin/sh
 # reindent a libpng C source
 # COPYRIGHT: Written by Glenn Randers-Pehrson, 2016.
 # To the extent possible under law, the author has waived all copyright and
 # related or neighboring rights to this work.  This work is published from:
 # United States.
 # Usage:
 # reindent inputtabsize outputtabsize inputcontinuestring outputcontinuestring
 #
 # Assumes that continued lines begin with indentation plus one space, and
 # that continued comments begin with indentation plus " *".
 #
 # eg, to change libpng coding style from 3-space indentation with 4-space
 # continuations to 4-space indentation with 2-space continuations:
 #
 #  reindent 3 4 "\t " "  " < example.c > example.c_4_2
 # and to restore the file back to libpng coding style
 #  reindent 4 3 "  " "    " < example.c_4_2 > example.c_3_4
 unexpand --first-only --t $1 | \
   sed -e "/^	*$3[^\*]/{s/$3/$4/}" | \
   expand -t $2
--- a/example.c
+++ b/example.c
@ -2,8 +2,8 @@
 #if 0 /* in case someone actually tries to compile this */
 /* example.c - an example of using libpng
- * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Maintained 1998-2014 Glenn Randers-Pehrson
+ * Maintained 1998-2016 Glenn Randers-Pehrson
 * Maintained 1996, 1997 Andreas Dilger)
 * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
 * To the extent possible under law, the authors have waived
@ -530,7 +530,7 @@ void read_png(FILE *fp, int sig_read)  /* File is already open */
    * see the png_read_row() method below:
    */
   number_passes = png_set_interlace_handling(png_ptr);
-#else
+#else /* !READ_INTERLACING */
   number_passes = 1;
 #endif /* READ_INTERLACING */
--- 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 1.6.23 - June 9, 2016
+ libpng version 1.6.24 - August 4, 2016
 Updated and distributed by Glenn Randers-Pehrson
 <glennrp at users.sourceforge.net>
 Copyright (c) 1998-2016 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 1.6.23 - June 9, 2016
+ libpng versions 0.97, January 1998, through 1.6.24 - August 4, 2016
 Updated and distributed by Glenn Randers-Pehrson
 Copyright (c) 1998-2016 Glenn Randers-Pehrson
@ -559,7 +559,7 @@ non-interlaced case the row that was just handled is simply one less than the
 passed in row number, and pass will always be 0.  For the interlaced case the
 same applies unless the row value is 0, in which case the row just handled was
 the last one from one of the preceding passes.  Because interlacing may skip a
-pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+pass you cannot be sure that the preceding pass is just 'pass-1'; if you really
 need to know what the last pass is record (row,pass) from the callback and use
 the last recorded value each time.
@ -2230,7 +2230,8 @@ is exactly the same.  If you are planning on displaying the image
 after each pass, the "rectangle" effect is generally considered the
 better looking one.
-If you only want the "sparkle" effect, just call png_read_rows() as
+If you only want the "sparkle" effect, just call png_read_row() or
 png_read_rows() as
 normal, with the third parameter NULL.  Make sure you make pass over
 the image number_of_passes times, and you don't change the data in the
 rows between calls.  You can change the locations of the data, just
@ -2239,6 +2240,8 @@ pass, and assumes the data from previous passes is still valid.
    png_read_rows(png_ptr, row_pointers, NULL,
        number_of_rows);
    or
    png_read_row(png_ptr, row_pointers, NULL);
 If you only want the first effect (the rectangles), do the same as
 before except pass the row buffer in the third parameter, and leave
@ -2246,6 +2249,8 @@ the second parameter NULL.
    png_read_rows(png_ptr, NULL, row_pointers,
        number_of_rows);
    or
    png_read_row(png_ptr, NULL, row_pointers);
 If you don't want libpng to handle the interlacing details, just call
 png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images.
@ -5345,7 +5350,7 @@ Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.23 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.24 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 "June 9, 2016"
+.TH LIBPNG 3 "August 4, 2016"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.23
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.24
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@ -510,7 +510,7 @@ 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 1.6.23 - June 9, 2016
+ libpng version 1.6.24 - August 4, 2016
 Updated and distributed by Glenn Randers-Pehrson
 <glennrp at users.sourceforge.net>
 Copyright (c) 1998-2016 Glenn Randers-Pehrson
@ -521,7 +521,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 Based on:
- libpng versions 0.97, January 1998, through 1.6.23 - June 9, 2016
+ libpng versions 0.97, January 1998, through 1.6.24 - August 4, 2016
 Updated and distributed by Glenn Randers-Pehrson
 Copyright (c) 1998-2016 Glenn Randers-Pehrson
@ -1069,7 +1069,7 @@ non-interlaced case the row that was just handled is simply one less than the
 passed in row number, and pass will always be 0.  For the interlaced case the
 same applies unless the row value is 0, in which case the row just handled was
 the last one from one of the preceding passes.  Because interlacing may skip a
-pass you cannot be sure that the preceding pass is just 'pass\-1', if you really
+pass you cannot be sure that the preceding pass is just 'pass\-1'; if you really
 need to know what the last pass is record (row,pass) from the callback and use
 the last recorded value each time.
@ -2740,7 +2740,8 @@ is exactly the same.  If you are planning on displaying the image
 after each pass, the "rectangle" effect is generally considered the
 better looking one.
-If you only want the "sparkle" effect, just call png_read_rows() as
+If you only want the "sparkle" effect, just call png_read_row() or
 png_read_rows() as
 normal, with the third parameter NULL.  Make sure you make pass over
 the image number_of_passes times, and you don't change the data in the
 rows between calls.  You can change the locations of the data, just
@ -2749,6 +2750,8 @@ pass, and assumes the data from previous passes is still valid.
    png_read_rows(png_ptr, row_pointers, NULL,
        number_of_rows);
    or
    png_read_row(png_ptr, row_pointers, NULL);
 If you only want the first effect (the rectangles), do the same as
 before except pass the row buffer in the third parameter, and leave
@ -2756,6 +2759,8 @@ the second parameter NULL.
    png_read_rows(png_ptr, NULL, row_pointers,
        number_of_rows);
    or
    png_read_row(png_ptr, NULL, row_pointers);
 If you don't want libpng to handle the interlacing details, just call
 png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images.
@ -5855,7 +5860,7 @@ Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.23 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.24 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
@ -5957,7 +5962,7 @@ the first widely used release:
 ...
 1.5.27                  15    10527  15.so.15.27[.0]
 ...
- 1.6.23                  16    10623  16.so.16.23[.0]
+ 1.6.24                  16    10624  16.so.16.24[.0]
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@ -6013,7 +6018,7 @@ possible without all of you.
 Thanks to Frank J. T. Wojcik for helping with the documentation.
-Libpng version 1.6.23 - June 9, 2016:
+Libpng version 1.6.24 - August 4, 2016:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
@ -6038,7 +6043,7 @@ this sentence.
 This code is released under the libpng license.
-libpng versions 1.0.7, July 1, 2000 through 1.6.23, June 9, 2016 are
+libpng versions 1.0.7, July 1, 2000 through 1.6.24, August 4, 2016 are
 Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
@ -6163,7 +6168,7 @@ files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-June 9, 2016
+August 4, 2016
 .\" end of man page
--- a/libpngpf.3
+++ b/libpngpf.3
@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "June 9, 2016"
+.TH LIBPNGPF 3 "August 4, 2016"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.23
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.24
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
--- a/png.5
+++ b/png.5
@ -1,4 +1,4 @@
-.TH PNG 5 "June 9, 2016"
+.TH PNG 5 "August 4, 2016"
 .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 1.6.19 [November 12, 2015]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 * Copyright (c) 1998-2002,2004,2006-2015 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_6_23 Your_png_h_is_not_version_1_6_23;
+typedef png_libpng_version_1_6_24 Your_png_h_is_not_version_1_6_24;
 /* 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
@ -775,14 +775,14 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
   return PNG_STRING_NEWLINE \
-      "libpng version 1.6.23 - June 9, 2016" PNG_STRING_NEWLINE \
+      "libpng version 1.6.24 - August 4, 2016" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson" \
      PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE;
 #  else
-   return "libpng version 1.6.23 - June 9, 2016\
+   return "libpng version 1.6.24 - August 4, 2016\
      Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson\
      Copyright (c) 1996-1997 Andreas Dilger\
      Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@ -2354,7 +2354,6 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
   return 0; /* no match */
 }
 #endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
 void /* PRIVATE */
 png_icc_set_sRGB(png_const_structrp png_ptr,
@ -2363,12 +2362,11 @@ png_icc_set_sRGB(png_const_structrp png_ptr,
   /* Is this profile one of the known ICC sRGB profiles?  If it is, just set
    * the sRGB information.
    */
 #if PNG_sRGB_PROFILE_CHECKS >= 0
   if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler) != 0)
 #endif
      (void)png_colorspace_set_sRGB(png_ptr, colorspace,
         (int)/*already checked*/png_get_uint_32(profile+64));
 }
 #endif /* PNG_sRGB_PROFILE_CHECKS >= 0 */
 #endif /* sRGB */
 int /* PRIVATE */
@ -2385,7 +2383,7 @@ png_colorspace_set_ICC(png_const_structrp png_ptr, png_colorspacerp colorspace,
       png_icc_check_tag_table(png_ptr, colorspace, name, profile_length,
           profile) != 0)
   {
-#     ifdef PNG_sRGB_SUPPORTED
+#     if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0
         /* If no sRGB support, don't try storing sRGB information */
         png_icc_set_sRGB(png_ptr, colorspace, profile, 0);
 #     endif
@ -4092,9 +4090,9 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
   /* Remove any existing table; this copes with multiple calls to
    * png_read_update_info. The warning is because building the gamma tables
-   * multiple times is a performance hit - it's harmless but the ability to call
+    * multiple times is a performance hit - it's harmless but the ability to
-   * png_read_update_info() multiple times is new in 1.5.6 so it seems sensible
+    * call png_read_update_info() multiple times is new in 1.5.6 so it seems
-   * to warn if the app introduces such a hit.
+    * sensible to warn if the app introduces such a hit.
    */
   if (png_ptr->gamma_table != NULL || png_ptr->gamma_16_table != NULL)
   {
@ -4105,7 +4103,8 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
   if (bit_depth <= 8)
   {
      png_build_8bit_table(png_ptr, &png_ptr->gamma_table,
-         png_ptr->screen_gamma > 0 ?  png_reciprocal2(png_ptr->colorspace.gamma,
+          png_ptr->screen_gamma > 0 ?
          png_reciprocal2(png_ptr->colorspace.gamma,
          png_ptr->screen_gamma) : PNG_FP_1);
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
@ -4117,7 +4116,8 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
             png_reciprocal(png_ptr->colorspace.gamma));
         png_build_8bit_table(png_ptr, &png_ptr->gamma_from_1,
-            png_ptr->screen_gamma > 0 ?  png_reciprocal(png_ptr->screen_gamma) :
+             png_ptr->screen_gamma > 0 ?
             png_reciprocal(png_ptr->screen_gamma) :
             png_ptr->colorspace.gamma/* Probably doing rgb_to_gray */);
      }
 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
@ -4148,8 +4148,8 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
       * pow(iv, gamma).
       *
       * Thus the gamma table consists of up to 256 256-entry tables.  The table
-      * is selected by the (8-gamma_shift) most significant of the low 8 bits of
+       * is selected by the (8-gamma_shift) most significant of the low 8 bits
-      * the color value then indexed by the upper 8 bits:
+       * of the color value then indexed by the upper 8 bits:
       *
       *   table[low bits][high 8 bits]
       *
@ -4182,8 +4182,8 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
      /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
       * PNG_COMPOSE).  This effectively smashed the background calculation for
-      * 16-bit output because the 8-bit table assumes the result will be reduced
+       * 16-bit output because the 8-bit table assumes the result will be
-      * to 8 bits.
+       * reduced to 8 bits.
       */
      if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) != 0)
          png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
--- a/png.h
+++ b/png.h
@ -1,7 +1,7 @@
 /* png.h - header file for PNG reference library
 *
- * libpng version 1.6.23, June 9, 2016
+ * libpng version 1.6.24, August 4, 2016
 *
 * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@ -12,7 +12,7 @@
 * Authors and maintainers:
 *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
 *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.23, June 9, 2016:
+ *   libpng versions 0.97, January 1998, through 1.6.24, August 4, 2016:
 *     Glenn Randers-Pehrson.
 *   See also "Contributing Authors", below.
 */
@ -29,7 +29,7 @@
 * files that are distributed with libpng have other copyright owners and
 * are released under other open source licenses.
 *
- * libpng versions 1.0.7, July 1, 2000 through 1.6.23, June 9, 2016 are
+ * libpng versions 1.0.7, July 1, 2000 through 1.6.24, August 4, 2016 are
 * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
 * derived from libpng-1.0.6, and are distributed according to the same
 * disclaimer and license as libpng-1.0.6 with the following individuals
@ -217,7 +217,7 @@
 *    ...
 *    1.5.27                  15    10527  15.so.15.27[.0]
 *    ...
- *    1.6.23                  16    10623  16.so.16.23[.0]
+ *    1.6.24                  16    10624  16.so.16.24[.0]
 *
 *    Henceforth the source version will match the shared-library major
 *    and minor numbers; the shared-library major version number will be
@ -245,13 +245,13 @@
 * Y2K compliance in libpng:
 * =========================
 *
- *    June 9, 2016
+ *    August 4, 2016
 *
 *    Since the PNG Development group is an ad-hoc body, we can't make
 *    an official declaration.
 *
 *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.23 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.24 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
@ -313,9 +313,8 @@
 */
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.23"
+#define PNG_LIBPNG_VER_STRING "1.6.24"
-#define PNG_HEADER_VERSION_STRING \
+#define PNG_HEADER_VERSION_STRING " libpng version 1.6.24 - August 4, 2016\n"
     " libpng version 1.6.23 - June 9, 2016\n"
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@ -323,7 +322,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 23
+#define PNG_LIBPNG_VER_RELEASE 24
 /* This should match the numeric part of the final component of
 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
@ -354,20 +353,20 @@
 * 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 10623 /* 1.6.23 */
+#define PNG_LIBPNG_VER 10624 /* 1.6.24 */
 /* Library configuration: these options cannot be changed after
 * the library has been built.
 */
 #ifndef PNGLCONF_H
-    /* If pnglibconf.h is missing, you can
+/* If pnglibconf.h is missing, you can
 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
 */
 #   include "pnglibconf.h"
 #endif
 #ifndef PNG_VERSION_INFO_ONLY
-   /* Machine specific configuration. */
+/* Machine specific configuration. */
 #  include "pngconf.h"
 #endif
@ -464,7 +463,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
 * do not agree upon the version number.
 */
-typedef char* png_libpng_version_1_6_23;
+typedef char* png_libpng_version_1_6_24;
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
 *
@ -2300,8 +2299,10 @@ PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
 *    except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
 *    be processed by libpng.
 */
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
    int keep, png_const_bytep chunk_list, int num_chunks));
 #endif /* HANDLE_AS_UNKNOWN */
 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
 * the result is therefore true (non-zero) if special handling is required,
@ -2309,7 +2310,7 @@ PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
 */
 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
    png_const_bytep chunk_name));
-#endif
+#endif /* SET_UNKNOWN_CHUNKS */
 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
@ -2531,18 +2532,22 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
 #  define png_composite(composite, fg, alpha, bg)        \
-     { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
+   {                                                     \
      png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
          * (png_uint_16)(alpha)                         \
          + (png_uint_16)(bg)*(png_uint_16)(255          \
          - (png_uint_16)(alpha)) + 128);                \
-       (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); }
+      (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
   }
 #  define png_composite_16(composite, fg, alpha, bg)     \
-     { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg)  \
+   {                                                     \
      png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
          * (png_uint_32)(alpha)                         \
          + (png_uint_32)(bg)*(65535                     \
          - (png_uint_32)(alpha)) + 32768);              \
-       (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); }
+      (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
   }
 #else  /* Standard method using integer division */
@ -2610,7 +2615,7 @@ PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
    ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
    : (png_int_32)png_get_uint_32(buf)))
-   /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
+/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
 * but defining a macro name prefixed with PNG_PREFIX.
 */
 #  ifndef PNG_PREFIX
--- a/pngconf.h
+++ b/pngconf.h
@ -1,9 +1,9 @@
 /* pngconf.h - machine configurable file for libpng
 *
- * libpng version 1.6.23, June 9, 2016
+ * libpng version 1.6.24, August 4, 2016
 *
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
--- a/pngerror.c
+++ b/pngerror.c
@ -1,8 +1,8 @@
 /* pngerror.c - stub functions for i/o and memory allocation
 *
- * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
--- a/pngget.c
+++ b/pngget.c
@ -1,8 +1,8 @@
 /* pngget.c - retrieval of values from info struct
 *
- * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
--- a/pngmem.c
+++ b/pngmem.c
@ -1,8 +1,8 @@
 /* pngmem.c - stub functions for memory allocation
 *
- * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2014,2016 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.)
 *
--- a/pngpread.c
+++ b/pngpread.c
@ -1,7 +1,7 @@
 /* pngpread.c - read a png file in push mode
 *
- * Last changed in libpng 1.6.23 [June 9, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 * Copyright (c) 1998-2002,2004,2006-2016 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.)
@ -77,7 +77,7 @@ png_process_data_pause(png_structrp png_ptr, int save)
 png_uint_32 PNGAPI
 png_process_data_skip(png_structrp png_ptr)
 {
-  /* TODO: Deprecate and remove this API.
+/* 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.
--- a/pngpriv.h
+++ b/pngpriv.h
@ -1,7 +1,7 @@
 /* pngpriv.h - private declarations for use inside libpng
 *
- * Last changed in libpng 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 * Copyright (c) 1998-2002,2004,2006-2016 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.)
@ -1174,6 +1174,7 @@ PNG_INTERNAL_FUNCTION(void,png_do_write_interlace,(png_row_infop row_info,
 PNG_INTERNAL_FUNCTION(void,png_read_filter_row,(png_structrp pp, png_row_infop
    row_info, png_bytep row, png_const_bytep prev_row, int filter),PNG_EMPTY);
 #if PNG_ARM_NEON_OPT > 0
 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,(png_row_infop row_info,
    png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,(png_row_infop
@ -1188,6 +1189,7 @@ PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop
    row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY);
 #endif
 /* Choose the best filter to use and filter the row data */
 PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr,
@ -1913,8 +1915,10 @@ PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structp png_ptr,
    * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
    * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
    */
 #  if PNG_ARM_NEON_OPT > 0
 PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
 #  endif
 #endif
 PNG_INTERNAL_FUNCTION(png_uint_32, png_check_keyword, (png_structrp png_ptr,
--- a/pngread.c
+++ b/pngread.c
@ -1,7 +1,7 @@
 /* pngread.c - read a PNG file
 *
- * Last changed in libpng 1.6.23 [June 9, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 * Copyright (c) 1998-2002,2004,2006-2016 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.)
@ -1030,8 +1030,7 @@ png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn)
 #ifdef PNG_INFO_IMAGE_SUPPORTED
 void PNGAPI
 png_read_png(png_structrp png_ptr, png_inforp info_ptr,
-                           int transforms,
+    int transforms, voidp params)
                           voidp params)
 {
   if (png_ptr == NULL || info_ptr == NULL)
      return;
@ -2105,7 +2104,7 @@ png_image_read_colormap(png_voidp argument)
      else if (display->background == NULL /* no way to remove it */)
         png_error(png_ptr,
-            "a background color must be supplied to remove alpha/transparency");
+             "background color must be supplied to remove alpha/transparency");
      /* Get a copy of the background color (this avoids repeating the checks
       * below.)  The encoding is 8-bit sRGB or 16-bit linear, depending on the
@ -2430,8 +2429,8 @@ png_image_read_colormap(png_voidp argument)
               background_index = i;
               png_create_colormap_entry(display, i++, back_r, back_g, back_b,
 #ifdef __COVERITY__
-                 /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+                   /* Coverity claims that output_encoding
-                  * here.
+                    * cannot be 2 (P_LINEAR) here.
                    */ 255U,
 #else
                    output_encoding == P_LINEAR ? 65535U : 255U,
@ -2819,12 +2818,12 @@ png_image_read_colormap(png_voidp argument)
                      * on the sRGB color in 'back'.
                      */
                     png_create_colormap_entry(display, i,
-                        png_colormap_compose(display, colormap[i].red, P_FILE,
+                         png_colormap_compose(display, colormap[i].red,
-                           trans[i], back_r, output_encoding),
+                             P_FILE, trans[i], back_r, output_encoding),
-                        png_colormap_compose(display, colormap[i].green, P_FILE,
+                         png_colormap_compose(display, colormap[i].green,
-                           trans[i], back_g, output_encoding),
+                             P_FILE, trans[i], back_g, output_encoding),
-                        png_colormap_compose(display, colormap[i].blue, P_FILE,
+                         png_colormap_compose(display, colormap[i].blue,
-                           trans[i], back_b, output_encoding),
+                             P_FILE, trans[i], back_b, output_encoding),
                         output_encoding == P_LINEAR ? trans[i] * 257U :
                             trans[i],
                         output_encoding);
@ -3433,8 +3432,7 @@ png_image_read_background(png_voidp argument)
            for (pass = 0; pass < passes; ++pass)
            {
-               png_bytep        row = png_voidcast(png_bytep,
+               png_bytep row = png_voidcast(png_bytep, display->first_row);
                                                   display->first_row);
               unsigned int     startx, stepx, stepy;
               png_uint_32      y;
@ -4087,6 +4085,12 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
       */
      const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format);
      /* The following checks just the 'row_stride' calculation to ensure it
       * fits in a signed 32-bit value.  Because channels/components can be
       * either 1 or 2 bytes in size the length of a row can still overflow 32
       * bits; this is just to verify that the 'row_stride' argument can be
       * represented.
       */
      if (image->width <= 0x7FFFFFFFU/channels) /* no overflow */
      {
         png_uint_32 check;
@ -4101,13 +4105,30 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
         else
            check = row_stride;
         /* This verifies 'check', the absolute value of the actual stride
          * passed in and detects overflow in the application calculation (i.e.
          * if the app did actually pass in a non-zero 'row_stride'.
          */
         if (image->opaque != NULL && buffer != NULL && check >= png_row_stride)
         {
            /* Now check for overflow of the image buffer calculation; this
             * limits the whole image size to 32 bits for API compatibility with
             * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro.
             *
             * The PNG_IMAGE_BUFFER_SIZE macro is:
             *
             *    (PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)*height*(row_stride))
             *
             * And the component size is always 1 or 2, so make sure that the
             * number of *bytes* that the application is saying are available
             * does actually fit into a 32-bit number.
             *
             * NOTE: this will be changed in 1.7 because PNG_IMAGE_BUFFER_SIZE
             * will be changed to use png_alloc_size_t; bigger images can be
             * accomodated on 64-bit systems.
             */
-            if (image->height <= 0xFFFFFFFF/png_row_stride)
+            if (image->height <=
                0xFFFFFFFFU/PNG_IMAGE_PIXEL_COMPONENT_SIZE(image->format)/check)
            {
               if ((image->format & PNG_FORMAT_FLAG_COLORMAP) == 0 ||
                  (image->colormap_entries > 0 && colormap != NULL))
@ -4127,7 +4148,8 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
                   * all the setup has already been done.
                   */
                  if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
-                     result = png_safe_execute(image,
+                     result =
                         png_safe_execute(image,
                             png_image_read_colormap, &display) &&
                             png_safe_execute(image,
                             png_image_read_colormapped, &display);
--- a/pngrio.c
+++ b/pngrio.c
@ -1,8 +1,8 @@
 /* pngrio.c - functions for data input
 *
- * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
--- a/pngrtran.c
+++ b/pngrtran.c
@ -1,7 +1,7 @@
 /* pngrtran.c - transforms the data in a row for PNG readers
 *
- * Last changed in libpng 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 * Copyright (c) 1998-2002,2004,2006-2016 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.)
--- a/pngrutil.c
+++ b/pngrutil.c
@ -1,8 +1,8 @@
 /* pngrutil.c - utilities to read a PNG file
 *
- * Last changed in libpng 1.6.20 [December 3, 2014]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
@ -590,6 +590,7 @@ png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
   }
 }
 #if defined(PNG_READ_zTXt_SUPPORTED) || defined (PNG_READ_iTXt_SUPPORTED)
 /*
 * Decompress trailing data in a chunk.  The assumption is that read_buffer
 * points at an allocated area holding the contents of a chunk with a
@ -754,6 +755,7 @@ png_decompress_chunk(png_structrp png_ptr,
      return Z_MEM_ERROR;
   }
 }
 #endif /* READ_zTXt || READ_iTXt */
 #endif /* READ_COMPRESSED_TEXT */
 #ifdef PNG_READ_iCCP_SUPPORTED
@ -802,8 +804,8 @@ png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size,
          * the available output is produced; this allows reading of truncated
          * streams.
          */
-         ret = PNG_INFLATE(png_ptr,
+         ret = PNG_INFLATE(png_ptr, *chunk_bytes > 0 ?
-            *chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
+             Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
      }
      while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0));
@ -1512,7 +1514,7 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
                                    png_crc_finish(png_ptr, length);
                                    finished = 1;
-#                                   ifdef PNG_sRGB_SUPPORTED
+# if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0
                                    /* Check for a match against sRGB */
                                    png_icc_set_sRGB(png_ptr,
                                        &png_ptr->colorspace, profile,
@ -3418,8 +3420,8 @@ png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
                  /* Everything is aligned for png_uint_16 copies, but try for
                   * png_uint_32 first.
                   */
-                  if (png_isaligned(dp, png_uint_32) != 0 &&
+                  if (png_isaligned(dp, png_uint_32) &&
-                      png_isaligned(sp, png_uint_32) != 0 &&
+                      png_isaligned(sp, png_uint_32) &&
                      bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
                      bytes_to_jump % (sizeof (png_uint_32)) == 0)
                  {
--- a/pngset.c
+++ b/pngset.c
@ -1,7 +1,7 @@
 /* pngset.c - storage of image information into info struct
 *
- * Last changed in libpng 1.6.23 [June 9, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 * Copyright (c) 1998-2016 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.)
@ -1662,7 +1662,9 @@ png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
 png_uint_32 /* PRIVATE */
 png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
 {
 #ifdef PNG_WARNINGS_SUPPORTED
   png_const_charp orig_key = key;
 #endif
   png_uint_32 key_len = 0;
   int bad_character = 0;
   int space = 1;
@ -1725,7 +1727,9 @@ png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
      png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
   }
-#endif /* WARNINGS */
+#else /* !WARNINGS */
   PNG_UNUSED(png_ptr)
 #endif /* !WARNINGS */
   return key_len;
 }
--- a/pngstruct.h
+++ b/pngstruct.h
@ -1,8 +1,8 @@
 /* pngstruct.h - header file for PNG reference library
 *
- * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
@ -249,7 +249,7 @@ struct png_struct_def
   png_byte filter;           /* file filter type (always 0) */
   png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
   png_byte pass;             /* current interlace pass (0 - 6) */
-   png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
+   png_byte do_filter;        /* row filter flags (see PNG_FILTER_ in png.h ) */
   png_byte color_type;       /* color type of file */
   png_byte bit_depth;        /* bit depth of file */
   png_byte usr_bit_depth;    /* bit depth of users row: write only */
--- a/pngtest.c
+++ b/pngtest.c
@ -1,8 +1,8 @@
 /* pngtest.c - a simple test program to test libpng
 *
- * Last changed in libpng 1.5.25 [December 3, 2015]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
@ -1690,7 +1690,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
            if (wrote_question == 0 && unsupported_chunks == 0)
            {
               fprintf(STDERR,
-         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                   "   Was %s written with the same maximum IDAT"
                   " chunk size (%d bytes),",
                   inname, PNG_ZBUF_SIZE);
               fprintf(STDERR,
                   "\n   filtering heuristic (libpng default), compression");
@ -1721,7 +1722,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
            if (wrote_question == 0 && unsupported_chunks == 0)
            {
               fprintf(STDERR,
-         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                   "   Was %s written with the same maximum"
                   " IDAT chunk size (%d bytes),",
                    inname, PNG_ZBUF_SIZE);
               fprintf(STDERR,
                   "\n   filtering heuristic (libpng default), compression");
@ -2079,4 +2081,4 @@ main(void)
 #endif
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_23 Your_png_h_is_not_version_1_6_23;
+typedef png_libpng_version_1_6_24 Your_png_h_is_not_version_1_6_24;
--- a/pngtrans.c
+++ b/pngtrans.c
@ -1,8 +1,8 @@
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
 *
- * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
@ -172,7 +172,8 @@ png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
                   * size!
                   */
                  png_app_error(png_ptr,
-                     "png_set_filler is invalid for low bit depth gray output");
+                      "png_set_filler is invalid for"
                      " low bit depth gray output");
                  return;
               }
--- a/pngwio.c
+++ b/pngwio.c
@ -1,8 +1,8 @@
 /* pngwio.c - functions for data output
 *
- * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2014 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2014,2016 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.)
 *
--- a/pngwrite.c
+++ b/pngwrite.c
@ -1,8 +1,8 @@
 /* pngwrite.c - general routines to write a PNG file
 *
- * Last changed in libpng 1.6.19 [November 12, 2015]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
--- a/pngwtran.c
+++ b/pngwtran.c
@ -1,8 +1,8 @@
 /* pngwtran.c - transforms the data in a row for PNG writers
 *
- * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
 *
--- a/pngwutil.c
+++ b/pngwutil.c
@ -1,7 +1,7 @@
 /* pngwutil.c - utilities to write a PNG file
 *
- * Last changed in libpng 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.24 [August 4, 2016]
 * Copyright (c) 1998-2002,2004,2006-2016 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.)
@ -1441,7 +1441,8 @@ png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)
 #endif
      {
         png_warning(png_ptr,
-             "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+             "Ignoring attempt to write 16-bit bKGD chunk "
             "when bit_depth is 8");
         return;
      }
@ -2262,14 +2263,22 @@ png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp,
        i++, rp++, dp++)
   {
      v = *dp = *rp;
 #ifdef PNG_USE_ABS
      sum += 128 - abs(v - 128);
 #else
      sum += (v < 128) ? v : 256 - v;
 #endif
   }
   for (lp = png_ptr->row_buf + 1; i < row_bytes;
      i++, rp++, lp++, dp++)
   {
      v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
 #ifdef PNG_USE_ABS
      sum += 128 - abs(v - 128);
 #else
      sum += (v < 128) ? v : 256 - v;
 #endif
      if (sum > lmins)  /* We are already worse, don't continue. */
        break;
@ -2278,6 +2287,28 @@ png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp,
   return (sum);
 }
 static void /* PRIVATE */
 png_setup_sub_row_only(png_structrp png_ptr, const png_uint_32 bpp,
    const png_size_t row_bytes)
 {
   png_bytep rp, dp, lp;
   png_size_t i;
   png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
        i++, rp++, dp++)
   {
      *dp = *rp;
   }
   for (lp = png_ptr->row_buf + 1; i < row_bytes;
      i++, rp++, lp++, dp++)
   {
      *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
   }
 }
 static png_size_t /* PRIVATE */
 png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes,
    const png_size_t lmins)
@ -2294,7 +2325,11 @@ png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes,
       i++, rp++, pp++, dp++)
   {
      v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
 #ifdef PNG_USE_ABS
      sum += 128 - abs(v - 128);
 #else
      sum += (v < 128) ? v : 256 - v;
 #endif
      if (sum > lmins)  /* We are already worse, don't continue. */
        break;
@ -2302,6 +2337,21 @@ png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes,
   return (sum);
 }
 static void /* PRIVATE */
 png_setup_up_row_only(png_structrp png_ptr, const png_size_t row_bytes)
 {
   png_bytep rp, dp, pp;
   png_size_t i;
   png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
       pp = png_ptr->prev_row + 1; i < row_bytes;
       i++, rp++, pp++, dp++)
   {
      *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
   }
 }
 static png_size_t /* PRIVATE */
 png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp,
@ -2319,7 +2369,11 @@ png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp,
   {
      v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
 #ifdef PNG_USE_ABS
      sum += 128 - abs(v - 128);
 #else
      sum += (v < 128) ? v : 256 - v;
 #endif
   }
   for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
@ -2327,7 +2381,11 @@ png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp,
      v = *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
          & 0xff);
 #ifdef PNG_USE_ABS
      sum += 128 - abs(v - 128);
 #else
      sum += (v < 128) ? v : 256 - v;
 #endif
      if (sum > lmins)  /* We are already worse, don't continue. */
        break;
@ -2335,6 +2393,27 @@ png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp,
   return (sum);
 }
 static void /* PRIVATE */
 png_setup_avg_row_only(png_structrp png_ptr, const png_uint_32 bpp,
    const png_size_t row_bytes)
 {
   png_bytep rp, dp, pp, lp;
   png_uint_32 i;
   png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
       pp = png_ptr->prev_row + 1; i < bpp; i++)
   {
      *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
   }
   for (lp = png_ptr->row_buf + 1; i < row_bytes; i++)
   {
      *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
          & 0xff);
   }
 }
 static png_size_t /* PRIVATE */
 png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp,
@ -2352,7 +2431,11 @@ png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp,
   {
      v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
 #ifdef PNG_USE_ABS
      sum += 128 - abs(v - 128);
 #else
      sum += (v < 128) ? v : 256 - v;
 #endif
   }
   for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
@ -2381,7 +2464,11 @@ png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp,
      v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
 #ifdef PNG_USE_ABS
      sum += 128 - abs(v - 128);
 #else
      sum += (v < 128) ? v : 256 - v;
 #endif
      if (sum > lmins)  /* We are already worse, don't continue. */
        break;
@ -2389,6 +2476,48 @@ png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp,
   return (sum);
 }
 static void /* PRIVATE */
 png_setup_paeth_row_only(png_structrp png_ptr, const png_uint_32 bpp,
    const png_size_t row_bytes)
 {
   png_bytep rp, dp, pp, cp, lp;
   png_size_t i;
   png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
   for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
       pp = png_ptr->prev_row + 1; i < bpp; i++)
   {
      *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
   }
   for (lp = png_ptr->row_buf + 1, cp = png_ptr->prev_row + 1; i < row_bytes;
        i++)
   {
      int a, b, c, pa, pb, pc, p;
      b = *pp++;
      c = *cp++;
      a = *lp++;
      p = b - c;
      pc = a - c;
 #ifdef PNG_USE_ABS
      pa = abs(p);
      pb = abs(pc);
      pc = abs(p + pc);
 #else
      pa = p < 0 ? -p : p;
      pb = pc < 0 ? -pc : pc;
      pc = (p + pc) < 0 ? -(p + pc) : p + pc;
 #endif
      p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
      *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
   }
 }
 #endif /* WRITE_FILTER */
 void /* PRIVATE */
@ -2397,7 +2526,7 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
 #ifndef PNG_WRITE_FILTER_SUPPORTED
   png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1);
 #else
-   png_byte filter_to_do = png_ptr->do_filter;
+   unsigned int filter_to_do = png_ptr->do_filter;
   png_bytep row_buf;
   png_bytep best_row;
   png_uint_32 bpp;
@ -2443,32 +2572,33 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
    */
   best_row = png_ptr->row_buf;
-
+   if (PNG_SIZE_MAX/128 <= row_bytes)
   if ((filter_to_do & PNG_FILTER_NONE) != 0 && filter_to_do != PNG_FILTER_NONE)
   {
      /* Overflow can occur in the calculation, just select the lowest set
       * filter.
       */
      filter_to_do &= 0U-filter_to_do;
   }
   else if ((filter_to_do & PNG_FILTER_NONE) != 0 &&
         filter_to_do != PNG_FILTER_NONE)
   {
      /* Overflow not possible and multiple filters in the list, including the
       * 'none' filter.
       */
      png_bytep rp;
      png_size_t sum = 0;
      png_size_t i;
      int v;
      if (PNG_SIZE_MAX/128 <= row_bytes)
      {
         for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
         {
            /* Check for overflow */
            if (sum > PNG_SIZE_MAX/128 - 256)
               break;
            v = *rp;
            sum += (v < 128) ? v : 256 - v;
         }
      }
      else /* Overflow is not possible */
      {
         for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
         {
            v = *rp;
 #ifdef PNG_USE_ABS
            sum += 128 - abs(v - 128);
 #else
            sum += (v < 128) ? v : 256 - v;
 #endif
         }
      }
@ -2479,7 +2609,7 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
   if (filter_to_do == PNG_FILTER_SUB)
   /* It's the only filter so no testing is needed */
   {
-      (void) png_setup_sub_row(png_ptr, bpp, row_bytes, mins);
+      png_setup_sub_row_only(png_ptr, bpp, row_bytes);
      best_row = png_ptr->try_row;
   }
@ -2505,7 +2635,7 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
   /* Up filter */
   if (filter_to_do == PNG_FILTER_UP)
   {
-      (void) png_setup_up_row(png_ptr, row_bytes, mins);
+      png_setup_up_row_only(png_ptr, row_bytes);
      best_row = png_ptr->try_row;
   }
@ -2531,7 +2661,7 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
   /* Avg filter */
   if (filter_to_do == PNG_FILTER_AVG)
   {
-      (void) png_setup_avg_row(png_ptr, bpp, row_bytes, mins);
+      png_setup_avg_row_only(png_ptr, bpp, row_bytes);
      best_row = png_ptr->try_row;
   }
@ -2555,9 +2685,9 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
   }
   /* Paeth filter */
-   if ((filter_to_do == PNG_FILTER_PAETH) != 0)
+   if (filter_to_do == PNG_FILTER_PAETH)
   {
-      (void) png_setup_paeth_row(png_ptr, bpp, row_bytes, mins);
+      png_setup_paeth_row_only(png_ptr, bpp, row_bytes);
      best_row = png_ptr->try_row;
   }
--- a/projects/vstudio/README.txt
+++ b/projects/vstudio/README.txt
@ -1,7 +1,7 @@
 VisualStudio instructions
-libpng version 1.6.23 - June 9, 2016
+libpng version 1.6.24 - August 4, 2016
 Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson
@ -93,3 +93,5 @@ as follows:
    DLL               /MD         /MDd
    Static Library    /MD         /MDd
 Also, be sure to build libpng, zlib, and your project all for the same
 platform (e.g., 32-bit or 64-bit).
--- a/projects/vstudio/libpng/libpng.vcxproj
+++ b/projects/vstudio/libpng/libpng.vcxproj
@ -84,7 +84,7 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <PrecompiledHeader>Use</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
@ -97,9 +97,9 @@
      <BrowseInformation>true</BrowseInformation>
      <CompileAs>CompileAsC</CompileAs>
      <StringPooling>true</StringPooling>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <Optimization>Disabled</Optimization>
      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
    </ClCompile>
@ -114,7 +114,7 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
    <ClCompile>
      <PrecompiledHeader>Use</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
@ -128,9 +128,9 @@
      <BrowseInformation>true</BrowseInformation>
      <CompileAs>CompileAsC</CompileAs>
      <StringPooling>true</StringPooling>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
    </ClCompile>
    <Link>
@ -140,7 +140,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>Use</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <FunctionLevelLinking>true</FunctionLevelLinking>
@ -153,9 +153,9 @@
      <CompileAs>CompileAsC</CompileAs>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <Optimization>Full</Optimization>
    </ClCompile>
    <Link>
@ -170,7 +170,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>Use</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
@ -184,9 +184,9 @@
      <CompileAs>CompileAsC</CompileAs>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <Optimization>Full</Optimization>
      <WholeProgramOptimization>true</WholeProgramOptimization>
    </ClCompile>
--- a/projects/vstudio/pnglibconf/pnglibconf.vcxproj
+++ b/projects/vstudio/pnglibconf/pnglibconf.vcxproj
@ -30,7 +30,7 @@
  </PropertyGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <Optimization>MaxSpeed</Optimization>
      <FunctionLevelLinking>true</FunctionLevelLinking>
      <IntrinsicFunctions>true</IntrinsicFunctions>
--- a/projects/vstudio/pngstest/pngstest.vcxproj
+++ b/projects/vstudio/pngstest/pngstest.vcxproj
@ -76,16 +76,16 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <StringPooling>true</StringPooling>
      <FunctionLevelLinking>false</FunctionLevelLinking>
@ -109,7 +109,7 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
    <ClCompile>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
@ -117,9 +117,9 @@
      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <StringPooling>true</StringPooling>
      <FunctionLevelLinking>false</FunctionLevelLinking>
@ -141,7 +141,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
@ -149,9 +149,9 @@
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
      <BrowseInformation>true</BrowseInformation>
@ -176,7 +176,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
@ -185,9 +185,9 @@
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
      <BrowseInformation>true</BrowseInformation>
--- a/projects/vstudio/pngtest/pngtest.vcxproj
+++ b/projects/vstudio/pngtest/pngtest.vcxproj
@ -76,16 +76,16 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <StringPooling>true</StringPooling>
      <FunctionLevelLinking>false</FunctionLevelLinking>
@ -109,7 +109,7 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
    <ClCompile>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
@ -117,9 +117,9 @@
      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <StringPooling>true</StringPooling>
      <FunctionLevelLinking>false</FunctionLevelLinking>
@ -141,7 +141,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
@ -149,9 +149,9 @@
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
      <BrowseInformation>true</BrowseInformation>
@ -176,7 +176,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
@ -185,9 +185,9 @@
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
      <BrowseInformation>true</BrowseInformation>
--- a/projects/vstudio/pngunknown/pngunknown.vcxproj
+++ b/projects/vstudio/pngunknown/pngunknown.vcxproj
@ -76,16 +76,16 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <StringPooling>true</StringPooling>
      <FunctionLevelLinking>false</FunctionLevelLinking>
@ -109,7 +109,7 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
    <ClCompile>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
@ -117,9 +117,9 @@
      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <StringPooling>true</StringPooling>
      <FunctionLevelLinking>false</FunctionLevelLinking>
@ -141,7 +141,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
@ -149,9 +149,9 @@
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
      <BrowseInformation>true</BrowseInformation>
@ -176,7 +176,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
@ -185,9 +185,9 @@
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
      <BrowseInformation>true</BrowseInformation>
--- a/projects/vstudio/pngvalid/pngvalid.vcxproj
+++ b/projects/vstudio/pngvalid/pngvalid.vcxproj
@ -76,16 +76,16 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <StringPooling>true</StringPooling>
      <FunctionLevelLinking>false</FunctionLevelLinking>
@ -109,7 +109,7 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
    <ClCompile>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <MinimalRebuild>false</MinimalRebuild>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
@ -117,9 +117,9 @@
      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
      <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <StringPooling>true</StringPooling>
      <FunctionLevelLinking>false</FunctionLevelLinking>
@ -141,7 +141,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
@ -149,9 +149,9 @@
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;PNG_USE_DLL;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
      <BrowseInformation>true</BrowseInformation>
@ -176,7 +176,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
    <ClCompile>
-      <WarningLevel>Level4</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <PrecompiledHeader>NotUsing</PrecompiledHeader>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
@ -185,9 +185,9 @@
      <IntrinsicFunctions>true</IntrinsicFunctions>
      <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <AdditionalIncludeDirectories>$(ZLibSrcDir);..\..\..\scripts;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <DisableSpecificWarnings>4996;4127</DisableSpecificWarnings>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings)</DisableSpecificWarnings>
      <CompileAsManaged>false</CompileAsManaged>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <StringPooling>true</StringPooling>
      <MinimalRebuild>false</MinimalRebuild>
      <BrowseInformation>true</BrowseInformation>
--- a/projects/vstudio/zlib.props
+++ b/projects/vstudio/zlib.props
@ -2,7 +2,7 @@
 <!--
 * zlib.props - location of zlib source
 *
- * libpng version 1.6.23 - June 9, 2016
+ * libpng version 1.6.24 - August 4, 2016
 *
 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
 *
@ -41,5 +41,18 @@
         test it:
     -->
    <WindowsSDKDesktopARMSupport>true</WindowsSDKDesktopARMSupport>
    <!-- The following lines provide a global (solution level) control of the
         warnings issued by the compiler, these are used in the individual
         project files (*/*.vcxproj) with, for zlib, some extra disables.
         Different versions of Visual Studio may require different settings,
         these settings work with Visual Studio 2013.  Just set
         TreatWarningAsError to false to check the build without failing on
         errors.
     -->
   <WarningLevel>EnableAllWarnings</WarningLevel>
   <TreatWarningAsError>true</TreatWarningAsError>
   <DisableSpecificWarnings>4255;4668;4710;4711;4746;4820;4996</DisableSpecificWarnings>
  </PropertyGroup>
 </Project>
--- a/projects/vstudio/zlib/zlib.vcxproj
+++ b/projects/vstudio/zlib/zlib.vcxproj
@ -88,11 +88,13 @@
    <ClCompile>
      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;Z_SOLO;%(PreprocessorDefinitions)</PreprocessorDefinitions>
      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
-      <WarningLevel>TurnOffAllWarnings</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
      <BrowseInformation>true</BrowseInformation>
      <FunctionLevelLinking>true</FunctionLevelLinking>
      <DisableSpecificWarnings>$(DisableSpecificWarnings);4127;4131;4242;4244</DisableSpecificWarnings>
      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
    </ClCompile>
    <Link>
      <TargetMachine>MachineX86</TargetMachine>
@ -103,11 +105,13 @@
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
    <ClCompile>
      <PreprocessorDefinitions>WIN32;_DEBUG;_WINDOWS;Z_SOLO;%(PreprocessorDefinitions)</PreprocessorDefinitions>
-      <WarningLevel>TurnOffAllWarnings</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Disabled</Optimization>
      <BrowseInformation>true</BrowseInformation>
      <FunctionLevelLinking>true</FunctionLevelLinking>
      <DisableSpecificWarnings>$(DisableSpecificWarnings);4127;4131;4242;4244</DisableSpecificWarnings>
      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
    </ClCompile>
    <Link>
@ -118,7 +122,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
    <ClCompile>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
      <IntrinsicFunctions>true</IntrinsicFunctions>
@ -126,7 +130,8 @@
      <BufferSecurityCheck>false</BufferSecurityCheck>
      <BrowseInformation>true</BrowseInformation>
      <FunctionLevelLinking>true</FunctionLevelLinking>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings);4127;4131;4242;4244</DisableSpecificWarnings>
      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;Z_SOLO;%(PreprocessorDefinitions)</PreprocessorDefinitions>
    </ClCompile>
@ -141,7 +146,7 @@
  </ItemDefinitionGroup>
  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
    <ClCompile>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>$(WarningLevel)</WarningLevel>
      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
      <Optimization>Full</Optimization>
      <IntrinsicFunctions>true</IntrinsicFunctions>
@ -149,7 +154,8 @@
      <BufferSecurityCheck>false</BufferSecurityCheck>
      <BrowseInformation>true</BrowseInformation>
      <FunctionLevelLinking>true</FunctionLevelLinking>
-      <TreatWarningAsError>true</TreatWarningAsError>
+      <DisableSpecificWarnings>$(DisableSpecificWarnings);4127;4131;4242;4244</DisableSpecificWarnings>
      <TreatWarningAsError>$(TreatWarningAsError)</TreatWarningAsError>
      <PreprocessorDefinitions>WIN32;NDEBUG;_WINDOWS;Z_SOLO;%(PreprocessorDefinitions)</PreprocessorDefinitions>
    </ClCompile>
    <Link>
--- a/scripts/README.txt
+++ b/scripts/README.txt
@ -1,9 +1,9 @@
-Makefiles for  libpng version 1.6.23 - June 9, 2016
+Makefiles for  libpng version 1.6.24 - August 4, 2016
 pnglibconf.h.prebuilt       =>  Stores configuration settings
 makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.23)
+                       (gcc, creates libpng16.so.16.1.6.24)
 makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
 makefile.knr      =>  Archaic UNIX Makefile that converts files with
                       ansi2knr (Requires ansi2knr.c from
@ -33,12 +33,12 @@ 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 libpng16.so.16.1.6.23)
+                       creates libpng16.so.16.1.6.24)
 makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
 makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng16.so.16.1.6.23)
+                       creates libpng16.so.16.1.6.24)
 makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng16.so.16.1.6.23)
+                       creates libpng16.so.16.1.6.24)
 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 1.6.23"
+PNG_DFN ";Version 1.6.24"
 #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=1.6.23
+version=1.6.24
 prefix=""
 libdir=""
 libs=""
--- a/scripts/libpng.pc.in
+++ b/scripts/libpng.pc.in
@ -5,6 +5,6 @@ includedir=@includedir@/libpng16
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.6.23
+Version: 1.6.24
 Libs: -L${libdir} -lpng16
 Cflags: -I${includedir}
--- a/scripts/makefile.cegcc
+++ b/scripts/makefile.cegcc
@ -23,7 +23,7 @@
 VERMAJ = 1
 VERMIN = 6
-VERMIC = 23
+VERMIC = 24
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)
--- a/scripts/makefile.linux
+++ b/scripts/makefile.linux
@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 23
+RELEASE = 24
 # Shared library names:
 LIBSO=$(LIBNAME).so
--- a/scripts/makefile.msys
+++ b/scripts/makefile.msys
@ -18,7 +18,7 @@ exec_prefix=$(prefix)
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 23
+RELEASE = 24
 # Shared library names:
 LIBSO=$(LIBNAME).dll
--- a/scripts/makefile.ne12bsd
+++ b/scripts/makefile.ne12bsd
@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng16
 LIB=	png16
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.6.23
+SHLIB_MINOR=	1.6.24
 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=	16
-SHLIB_MINOR=	1.6.23
+SHLIB_MINOR=	1.6.24
 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=	16
-SHLIB_MINOR=	1.6.23
+SHLIB_MINOR=	1.6.24
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \
--- a/scripts/pnglibconf.dfa
+++ b/scripts/pnglibconf.dfa
@ -552,6 +552,7 @@ option WRITE_ANCILLARY_CHUNKS requires WRITE
 # These options disable *all* the text chunks if turned off
 option TEXT disabled
 option READ_TEXT requires READ_ANCILLARY_CHUNKS enables TEXT
 option WRITE_TEXT requires WRITE_ANCILLARY_CHUNKS enables TEXT
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@ -1,8 +1,8 @@
-/* libpng 1.6.23 STANDARD API DEFINITION */
+/* libpng 1.6.24 STANDARD API DEFINITION */
 /* pnglibconf.h - library build configuration */
-/* Libpng version 1.6.23 - June 9, 2016 */
+/* Libpng version 1.6.24 - August 4, 2016 */
 /* Copyright (c) 1998-2015 Glenn Randers-Pehrson */
--- a/scripts/symbols.def
+++ b/scripts/symbols.def
@ -1,4 +1,4 @@
-;Version 1.6.23
+;Version 1.6.24
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng