[libpng16] Imported from libpng-1.6.18beta05.tar

pngwutil.c, introduced in libpng-0.95, March 1997.

ANNOUNCE

@@ -1,54 +1,66 @@
-Libpng 1.6.13 - August 21, 2014
+Libpng 1.6.18beta05 - May 31, 2015
 
-This is a public release of libpng, intended for use in production codes.
+This is not intended to be a public release.  It will be replaced
+within a few weeks by a public version or by another test version.
 
 Files available for download:
 
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   libpng-1.6.13.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.13.tar.gz
+   1.6.18beta05.tar.xz (LZMA-compressed, recommended)
+   1.6.18beta05.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lpng1613.7z  (LZMA-compressed, recommended)
-   lpng1613.zip
+   lp1618b05.7z  (LZMA-compressed, recommended)
+   lp1618b05.zip
 
 Other information:
 
-   libpng-1.6.13-README.txt
-   libpng-1.6.13-LICENSE.txt
-   libpng-1.6.13-*.asc (armored detached GPG signatures)
+   1.6.18beta05-README.txt
+   1.6.18beta05-LICENSE.txt
+   libpng-1.6.18beta05-*.asc (armored detached GPG signatures)
 
-Changes since the last public release (1.6.12):
+Changes since the last public release (1.6.17):
 
-  Quieted -Wsign-compare and -Wclobber compiler warnings in
-    contrib/pngminus/*.c
-  Added "(void) png_ptr;" where needed in contrib/gregbook to quiet
-    compiler complaints about unused pointers.
-  Split a long output string in contrib/gregbook/rpng2-x.c.
-  Added "PNG_SET_OPTION" requirement for sRGB chunk support to pnglibconf.dfa,
-    Needed for write-only support (John Bowler).
-  Changed "if defined(__ARM_NEON__)" to
-    "if (defined(__ARM_NEON__) || defined(__ARM_NEON))" (James Wu).
-  Fixed clang no-warning builds: png_digit was defined but never used.
-  Fixed an incorrect separator ("/" should be "\") in scripts/makefile.vcwin32
-    (bug report from Wolfgang S. Kechel).  Bug was introduced in libpng-1.6.11.
-    Also fixed makefile.bc32, makefile.bor, makefile.msc, makefile.intel, and
-    makefile.tc3 similarly.
-  Removed scripts/makefile.elf. It has not worked since libpng-1.5.0beta14
-    due to elimination of the PNG_FUNCTION_EXPORT and PNG_DATA_EXPORT
-    definitions from pngconf.h.
-  Ensure that CMakeLists.txt makes the target "lib" directory before making
-    symbolic link into it (SourceForge bug report #226 by Rolf Timmermans).
-  Added opinion that the ECCN (Export Control Classification Number) for
-    libpng is EAR99 to the README file.
-  Eliminated use of "$<" in makefile explicit rules, when copying
-    $PNGLIBCONF_H_PREBUILT.  This does not work on some versions of make;
-    bug introduced in libpng version 1.6.11.
-  Made "ccopts" agree with "CFLAGS" in scripts/makefile.hp* and makefile.*sunu
+Version 1.6.18beta01 [April 1, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
+  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
+    fixes some arithmetic errors that caused some tests to fail on
+    some 32-bit platforms (Bug reports by Peter Breitenlohner [i686]
+    and Petr Gajdos [i586]).
+
+Version 1.6.18beta02 [April 26, 2015]
+  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
+    (Bug report by Viktor Szaka'ts).
+
+Version 1.6.18beta03 [May 6, 2015]
+  Replaced "unexpected" with an integer (0xabadca11) in pngset.c
+    where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.
+  Added contrib/examples/simpleover.c, to demonstrate how to handle
+    alpha compositing of multiple images, using the "simplified API"
+    and an example PNG generation tool, contrib/examples/genpng.c
+    (John Bowler).
+
+Version 1.6.18beta04 [May 20, 2015]
+  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
+    type and can be defined on the command line, allowing testing in beta
+    builds (John Bowler).
+  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c
+  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
+    report from Christopher Ferris).
+
+Version 1.6.18beta05 [May 31, 2015]
+  Backport filter selection code from libpng-1.7.0beta51, to combine
+    sub_row, up_row, avg_row, and paeth_row into try_row and tst_row.
+  Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c
+    to avoid confusion with the libpng private macros.
+  Fixed old cut&paste bug in the weighted filter selection code in
+    pngwutil.c, introduced in libpng-0.95, March 1997.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -1,11 +1,14 @@
-
+#if 0
 CHANGES - changes for libpng
 
-Version 0.2
+version 0.1 [March 29, 1995]
+  initial work-in-progress release
+
+version 0.2 [April 1, 1995]
   added reader into png.h
   fixed small problems in stub file
 
-Version 0.3
+version 0.3 [April 8, 1995]
   added pull reader
   split up pngwrite.c to several files
   added pnglib.txt
@@ -14,9 +17,9 @@ Version 0.3
   fixed some bugs in writer
   interfaced with zlib 0.5
   added K&R support
-  added check for 64 KB blocks for 16-bit machines
+  added check for 64 KB blocks for 16 bit machines
 
-Version 0.4
+version 0.4 [April 26, 1995]
   cleaned up code and commented code
   simplified time handling into png_time
   created png_color_16 and png_color_8 to handle color needs
@@ -27,28 +30,29 @@ Version 0.4
   cleaned up zTXt reader and writer (using zlib's Reset functions)
   split transformations into pngrtran.c and pngwtran.c
 
-Version 0.5
+version 0.5 [April 30, 1995]
   interfaced with zlib 0.8
   fixed many reading and writing bugs
   saved using 3 spaces instead of tabs
 
-Version 0.6
+version 0.6 [May 1, 1995]
+  first beta release
   added png_large_malloc() and png_large_free()
   added png_size_t
   cleaned up some compiler warnings
   added png_start_read_image()
 
-Version 0.7
+version 0.7 [June 24, 1995]
   cleaned up lots of bugs
   finished dithering and other stuff
   added test program
   changed name from pnglib to libpng
 
-Version 0.71 [June, 1995]
+version 0.71 [June 26, 1995]
   changed pngtest.png for zlib 0.93
   fixed error in libpng.txt and example.c
 
-Version 0.8
+version 0.8 [August 20, 1995]
   cleaned up some bugs
   added png_set_filler()
   split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
@@ -1449,8 +1453,9 @@ Version 1.2.6beta4 [July 28, 2004]
   Use png_malloc instead of png_zalloc to allocate the pallete.
 
 Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
-  Fixed buffer overflow vulnerability in png_handle_tRNS()
-  Fixed integer arithmetic overflow vulnerability in png_read_png().
+  Fixed buffer overflow vulnerability (CVE-2004-0597) in png_handle_tRNS().
+  Fixed NULL dereference vulnerability (CVE-2004-0598) in png_handle_iCCP().
+  Fixed integer overflow vulnerability (CVE-2004-0599) in png_read_png().
   Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
     duplicate chunk types to go undetected.
   Fixed some timestamps in the -config version
@@ -2102,7 +2107,7 @@ Version 1.4.0beta24 [July 25, 2008]
     png_decompress_chunk(), and remove "chunkdata" from parameter list.
   Put a call to png_check_chunk_name() in png_read_chunk_header().
   Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
-  Removed two calls to png_check_chunk_name() occuring later in the process.
+  Removed two calls to png_check_chunk_name() occurring later in the process.
   Define PNG_NO_ERROR_NUMBERS by default in pngconf.h
 
 Version 1.4.0beta25 [July 30, 2008]
@@ -4430,7 +4435,7 @@ Version 1.6.1beta05 [March 1, 2013]
 Version 1.6.1beta06 [March 4, 2013]
   Better documentation of unknown handling API interactions.
   Corrected Android builds and corrected libpng.vers with symbol
-    prefixing This adds an API to set optimization options externally,
+    prefixing. This adds an API to set optimization options externally,
     providing an alternative and general solution for the non-portable
     run-time tests used by the ARM Neon code.  It also makes those tests
     compile and link on Android.
@@ -4978,6 +4983,270 @@ Version 1.6.13rc01 [August 14, 2014]
 Version 1.6.13 [August 21, 2014]
   No changes.
 
+Version 1.6.14beta01 [September 14, 2014]
+  Guard usage of png_ptr->options with #ifdef PNG_SET_OPTION_SUPPORTED.
+  Do not build contrib/tools/pngfix.c when PNG_SETJMP_NOT_SUPPORTED,
+    to allow "make" to complete without setjmp support (bug report by
+    Claudio Fontana)
+  Add "#include <setjmp.h>" to contrib/tools/pngfix.c (John Bowler)
+
+Version 1.6.14beta02 [September 18, 2014]
+  Use nanosleep() instead of usleep() in contrib/gregbook/rpng2-x.c
+    because usleep() is deprecated.
+  Define usleep() in contrib/gregbook/rpng2-x.c if not already defined
+    in unistd.h and nanosleep() is not available; fixes error introduced
+    in libpng-1.6.13.
+  Disable floating point exception handling in pngvalid.c when
+    PNG_FLOATING_ARITHMETIC is not supported (bug report by "zootus
+    at users.sourceforge.net").
+
+Version 1.6.14beta03 [September 19, 2014]
+  Define FE_DIVBYZERO, FE_INVALID, and FE_OVERFLOW in pngvalid.c if not
+    already defined.  Revert floating point exception handling in pngvalid.c
+    to version 1.6.14beta01 behavior.
+
+Version 1.6.14beta04 [September 27, 2014]
+  Fixed incorrect handling of the iTXt compression flag in pngrutil.c
+    (bug report by Shunsaku Hirata).  Bug was introduced in libpng-1.6.0.
+
+Version 1.6.14beta05 [October 1, 2014]
+  Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
+
+Version 1.6.14beta06 [October 5, 2014]
+  Removed unused "text_len" parameter from private function png_write_zTXt().
+  Conditionally compile some code in png_deflate_claim(), when
+    PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
+  Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
+  Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
+    to pnglibconf.dfa.
+  Removed "option READ_COMPRESSED_TEXT enables READ_TEXT" from pnglibconf.dfa,
+    to make it possible to configure a libpng that supports iCCP but not TEXT.
+
+Version 1.6.14beta07 [October 7, 2014]
+  Removed "option WRITE_COMPRESSED_TEXT enables WRITE_TEXT" from pnglibconf.dfa
+  Only mark text chunks as written after successfully writing them.
+
+Version 1.6.14rc01 [October 15, 2014]
+  Fixed some typos in comments.
+
+Version 1.6.14rc02 [October 17, 2014]
+  Changed png_convert_to_rfc_1123() to png_convert_to_rfc_1123_buffer()
+    in the manual, to reflect the change made in libpng-1.6.0.
+  Updated README file to explain that direct access to the png_struct
+    and info_struct members has not been permitted since libpng-1.5.0.
+
+Version 1.6.14 [October 23, 2014]
+  No changes.
+
+Version 1.6.15beta01 [October 29, 2014]
+  Changed "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
+  Simplified png_free_data().
+  Added missing "ptr = NULL" after some instances of png_free().
+
+Version 1.6.15beta02 [November 1, 2014]
+  Changed remaining "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
+
+Version 1.6.15beta03 [November 3, 2014]
+  Added PNG_USE_ARM_NEON configuration flag (Marcin Juszkiewicz).
+
+Version 1.6.15beta04 [November 4, 2014]
+  Removed new PNG_USE_ARM_NEON configuration flag and made a one-line
+    revision to configure.ac to support ARM on aarch64 instead (John Bowler).
+
+Version 1.6.15beta05 [November 5, 2014]
+  Use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING in
+    example.c, pngtest.c, and applications in the contrib directory.
+  Avoid out-of-bounds memory access in png_user_version_check().
+  Simplified and future-proofed png_user_version_check().
+  Fixed GCC unsigned int->float warnings. Various versions of GCC
+    seem to generate warnings when an unsigned value is implicitly
+    converted to double. This is probably a GCC bug but this change
+    avoids the issue by explicitly converting to (int) where safe.
+  Free all allocated memory in pngimage. The file buffer cache was left
+    allocated at the end of the program, harmless but it causes memory
+    leak reports from clang.
+  Fixed array size calculations to avoid warnings. At various points
+    in the code the number of elements in an array is calculated using
+    sizeof.  This generates a compile time constant of type (size_t) which
+    is then typically assigned to an (unsigned int) or (int). Some versions
+    of GCC on 64-bit systems warn about the apparent narrowing, even though
+    the same compiler does apparently generate the correct, in-range,
+    numeric constant.  This adds appropriate, safe, casts to make the
+    warnings go away.
+
+Version 1.6.15beta06 [November 6, 2014]
+  Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING
+    in the manual, example.c, pngtest.c, and applications in the contrib
+    directory.  It was incorrect advice.
+
+Version 1.6.15beta07 [November 7, 2014]
+  Removed #ifdef PNG_16BIT_SUPPORTED/#endif around png_product2(); it is
+    needed by png_reciprocal2().
+  Added #ifdef PNG_16BIT_SUPPORTED/#endif around png_log16bit() and
+    png_do_swap().
+  Changed all "#endif /* PNG_FEATURE_SUPPORTED */" to "#endif /* FEATURE */"
+
+Version 1.6.15beta08 [November 8, 2014]
+  More housecleaning in *.h
+
+Version 1.6.15rc01 [November 13, 2014]
+
+Version 1.6.15rc02 [November 14, 2014]
+  The macros passed in the command line to Borland make were ignored if
+    similarly-named macros were already defined in makefiles. This behavior
+    is different from POSIX make and other make programs.  Surround the
+    macro definitions with ifndef guards (Cosmin).
+
+Version 1.6.15rc03 [November 16, 2014]
+  Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32.
+  Removed the obsolete $ARCH variable from scripts/makefile.darwin.
+
+Version 1.6.15 [November 20, 2014]
+  No changes.
+
+Version 1.6.16beta01 [December 14, 2014]
+  Added ".align 2" to arm/filter_neon.S to support old GAS assemblers that
+    don't do alignment correctly.
+  Revised Makefile.am and scripts/symbols.dfn to work with MinGW/MSYS
+    (Bob Friesenhahn).
+
+Version 1.6.16beta02 [December 15, 2014]
+  Revised Makefile.am and scripts/*.dfn again to work with MinGW/MSYS;
+    renamed scripts/*.dfn to scripts/*.c (John Bowler).
+
+Version 1.6.16beta03 [December 21, 2014]
+  Quiet a "comparison always true" warning in pngstest.c (John Bowler).
+
+Version 1.6.16rc01 [December 21, 2014]
+  Restored a test on width that was removed from png.c at libpng-1.6.9
+    (Bug report by Alex Eubanks, CVE-2015-0973).
+
+Version 1.6.16rc02 [December 21, 2014]
+  Undid the update to pngrutil.c in 1.6.16rc01.
+
+Version 1.6.16rc03 [December 21, 2014]
+  Fixed an overflow in png_combine_row() with very wide interlaced images
+    (Bug report and fix by John Bowler, CVE-2014-9495).
+
+Version 1.6.16 [December 22, 2014]
+  No changes.
+
+Version 1.6.17beta01 [January 29, 2015]
+  Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
+  Corrected the width limit calculation in png_check_IHDR().
+  Removed user limits from pngfix. Also pass NULL pointers to
+    png_read_row to skip the unnecessary row de-interlace stuff.
+  Added testing of png_set_packing() to pngvalid.c
+  Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
+  Implement previously untested cases of libpng transforms in pngvalid.c
+  Fixed byte order in 2-byte filler, in png_do_read_filler().
+  Made the check for out-of-range values in png_set_tRNS() detect
+    values that are exactly 2^bit_depth, and work on 16-bit platforms.
+  Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47.
+  Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
+    pngset.c to avoid warnings about dead code.
+  Added "& 0xff" to many instances of expressions that are typecast
+    to (png_byte), to avoid Coverity warnings.
+
+Version 1.6.17beta02 [February 7, 2015]
+  Work around one more Coverity-scan dead-code warning.
+  Do not build png_product2() when it is unused.
+
+Version 1.6.17beta03 [February 17, 2015]
+  Display user limits in the output from pngtest.
+  Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column
+    and 1-million-row default limits in pnglibconf.dfa, that can be reset
+    by the user at build time or run time.  This provides a more robust
+    defense against DOS and as-yet undiscovered overflows.
+
+Version 1.6.17beta04 [February 21, 2015]
+  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
+  Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
+  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
+
+Version 1.6.17beta05 [February 25, 2015]
+  Restored compiling of png_reciprocal2 with PNG_NO_16BIT.
+
+Version 1.6.17beta06 [February 27, 2015]
+  Moved png_set_filter() prototype into a PNG_WRITE_SUPPORTED block
+    of png.h.
+  Avoid runtime checks when converting integer to png_byte with
+    Visual Studio (Sergey Kosarevsky)
+
+Version 1.6.17rc01 [March 4, 2015]
+  No changes.
+
+Version 1.6.17rc02 [March 9, 2015]
+  Removed some comments that the configure script did not handle
+    properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt.
+  Free the unknown_chunks structure even when it contains no data.
+
+Version 1.6.17rc03 [March 12, 2015]
+  Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF
+    for consistency, and remove some useless tests (Alexey Petruchik).
+
+Version 1.6.17rc04 [March 16, 2015]
+  Remove pnglibconf.h, pnglibconf.c, and pnglibconf.out instead of
+    pnglibconf.* in "make clean" (Cosmin).
+  Fix bug in calculation of maxbits, in png_write_sBIT, introduced
+    in libpng-1.6.17beta01 (John Bowler).
+
+Version 1.6.17rc05 [March 21, 2015]
+  Define PNG_FILTER_* and PNG_FILTER_VALUE_* in png.h even when WRITE
+    is not supported (John Bowler).  This fixes an error introduced in
+    libpng-1.6.17beta06.
+  Reverted "& 0xff" additions of version 1.6.17beta01. Libpng passes
+    the Coverity scan without them.
+
+Version 1.6.17rc06 [March 23, 2015]
+  Remove pnglibconf.dfn and pnglibconf.pre with "make clean".
+  Reformatted some "&0xff" instances to "& 0xff".
+  Fixed simplified 8-bit-linear to sRGB alpha. The calculated alpha
+    value was wrong.  It's not clear if this affected the final stored
+    value; in the obvious code path the upper and lower 8-bits of the
+    alpha value were identical and the alpha was truncated to 8-bits
+    rather than dividing by 257 (John Bowler).
+
+Version 1.6.17 [March 26, 2015]
+  No changes.
+
+Version 1.6.18beta01 [April 1, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
+  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
+    fixes some arithmetic errors that caused some tests to fail on
+    some 32-bit platforms (Bug reports by Peter Breitenlohner [i686]
+    and Petr Gajdos [i586]).
+
+Version 1.6.18beta02 [April 26, 2015]
+  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
+    (Bug report by Viktor Szaka'ts).
+
+Version 1.6.18beta03 [May 6, 2015]
+  Replaced "unexpected" with an integer (0xabadca11) in pngset.c
+    where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.
+  Added contrib/examples/simpleover.c, to demonstrate how to handle
+    alpha compositing of multiple images, using the "simplified API"
+    and an example PNG generation tool, contrib/examples/genpng.c
+    (John Bowler).
+
+Version 1.6.18beta04 [May 20, 2015]
+  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
+    type and can be defined on the command line, allowing testing in beta
+    builds (John Bowler).
+  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds.
+  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
+    report from Christopher Ferris).
+
+Version 1.6.18beta05 [May 31, 2015]
+  Backport filter selection code from libpng-1.7.0beta51, to combine
+    sub_row, up_row, avg_row, and paeth_row into try_row and tst_row.
+  Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c
+    to avoid confusion with the libpng private macros.
+  Fixed old cut&paste bug in the weighted filter selection code in
+    pngwutil.c, introduced in libpng-0.95, March 1997.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
@@ -4985,3 +5254,4 @@ to subscribe)
 or to glennrp at users.sourceforge.net
 
 Glenn R-P
+#endif

CMakeLists.txt

@@ -1,6 +1,6 @@
 # CMakeLists.txt
 
-# Copyright (C) 2007-2014 Glenn Randers-Pehrson
+# Copyright (C) 2007-2015 Glenn Randers-Pehrson
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -16,7 +16,7 @@ enable_testing()
 
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 13)
+set(PNGLIB_RELEASE 18)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
@@ -30,8 +30,7 @@ if(NOT WIN32)
     PATHS /usr/lib /usr/local/lib
   )
   if(NOT M_LIBRARY)
-    message(STATUS
-      "math library 'libm' not found - floating point support disabled")
+    message(STATUS "math lib 'libm' not found; floating point support disabled")
   endif()
 else()
   # not needed on windows
@@ -39,22 +38,14 @@ else()
 endif()
 
 # COMMAND LINE OPTIONS
-if(DEFINED PNG_SHARED)
-  option(PNG_SHARED "Build shared lib" ${PNG_SHARED})
-else()
-  option(PNG_SHARED "Build shared lib" ON)
-endif()
-if(DEFINED PNG_STATIC)
-  option(PNG_STATIC "Build static lib" ${PNG_STATIC})
-else()
-  option(PNG_STATIC "Build static lib" ON)
-endif()
-
-option(PNG_TESTS  "Build libpng tests" YES)
+option(PNG_SHARED "Build shared lib" ON)
+option(PNG_STATIC "Build static lib" ON)
+option(PNG_TESTS  "Build libpng tests" ON)
 
 # Many more configuration options could be added here
-option(PNG_DEBUG         "Build with debug output" NO)
-option(PNGARG            "Disable ANSI-C prototypes" NO)
+option(PNG_FRAMEWORK "Build OS X framework" OFF)
+option(PNG_DEBUG     "Build with debug output" OFF)
+option(PNGARG        "Disable ANSI-C prototypes" OFF)
 
 # SET LIBNAME
 set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
@@ -134,7 +125,7 @@ if(PNG_SHARED)
 endif()
 
 if(PNG_STATIC)
-# does not work without changing name
+  # does not work without changing name
   set(PNG_LIB_NAME_STATIC ${PNG_LIB_NAME}_static)
   add_library(${PNG_LIB_NAME_STATIC} STATIC ${libpng_sources})
   list(APPEND PNG_LIB_TARGETS ${PNG_LIB_NAME_STATIC})
@@ -145,10 +136,27 @@ if(PNG_STATIC)
   target_link_libraries(${PNG_LIB_NAME_STATIC} ${ZLIB_LIBRARY} ${M_LIBRARY})
 endif()
 
+if(PNG_FRAMEWORK)
+  set(PNG_LIB_NAME_FRAMEWORK ${PNG_LIB_NAME}_framework)
+  add_library(${PNG_LIB_NAME_FRAMEWORK} SHARED ${libpng_sources})
+  list(APPEND PNG_LIB_TARGETS ${PNG_LIB_NAME_FRAMEWORK})
+  set_target_properties(${PNG_LIB_NAME_FRAMEWORK} PROPERTIES
+    FRAMEWORK TRUE
+    FRAMEWORK_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_SHORT_VERSION_STRING ${PNGLIB_MAJOR}.${PNGLIB_MINOR}
+    MACOSX_FRAMEWORK_BUNDLE_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_IDENTIFIER org.libpng.libpng
+    XCODE_ATTRIBUTE_INSTALL_PATH "@rpath"
+    PUBLIC_HEADER "${libpng_public_hdrs}"
+    OUTPUT_NAME png)
+  target_link_libraries(${PNG_LIB_NAME_FRAMEWORK} ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
 if(NOT PNG_LIB_TARGETS)
   message(SEND_ERROR
     "No library variant selected to build. "
-    "Please enable at least one of the following options: PNG_STATIC, PNG_SHARED")
+    "Please enable at least one of the following options: "
+    " PNG_STATIC, PNG_SHARED, PNG_FRAMEWORK")
 endif()
 
 if(PNG_SHARED AND WIN32)
@@ -253,7 +261,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.13
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.18beta05
     VERSION 16.${PNGLIB_RELEASE}.0
     SOVERSION 16
     CLEAN_DIRECT_OUTPUT 1)
@@ -284,7 +292,8 @@ if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
       ${PNG_EXPORT_RULE}
       RUNTIME DESTINATION bin
       LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
   if(PNG_SHARED)
     # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin

INSTALL

@@ -17,8 +17,8 @@ VIII. Configuring libpng for 16-bit platforms
  XII. Configuring for compiler xxx:
 XIII. Removing unwanted object code
  XIV. Changes to the build and configuration of libpng in libpng-1.5.x
-  XV. Configuring libpng for multiprocessing
- XVI. Other sources of information about libpng:
+  XV. Setjmp/longjmp issues
+ XVI. Other sources of information about libpng
 
 I. Simple installation
 
@@ -32,6 +32,15 @@ and ignore the rest of this document.  "/path" is the path to the directory
 where you want to install the libpng "lib", "include", and "bin"
 subdirectories.
 
+If you downloaded a GIT clone, you will need to run ./autogen.sh before
+running ./configure, to create "configure" and "Makefile.in" which are
+not included in the GIT repository.
+
+Note that "configure" is only included in the "*.tar" distributions and not
+in the "*.zip" or "*.7z" distributions. If you downloaded one of those
+distributions, see "Building with project files" or "Building with makefiles",
+below.
+
 II. Rebuilding the configure scripts
 
 If configure does not work on your system, or if you have a need to
@@ -111,8 +120,7 @@ Your directory structure should look like this:
       libpng  (this directory)
           INSTALL (this file)
           README
-          *.h
-          *.c
+          *.h, *.c  => libpng source files
           CMakeLists.txt    =>  "cmake" script
           configuration files:
              configure.ac, configure, Makefile.am, Makefile.in,
@@ -120,15 +128,10 @@ Your directory structure should look like this:
              libpng-config.in, aclocal.m4, config.h.in, config.sub,
              depcomp, install-sh, mkinstalldirs, test-pngtest.sh
           contrib
-             gregbook
-             libtests
-             pngminim
-             pngminus
-             pngsuite
-             visupng
+             arm-neon, conftest, examples, gregbook, libtests, pngminim,
+             pngminus, pngsuite, tools, visupng
           projects
-             visualc71
-             vstudio
+             cbuilder5, owatcom, visualc71, vstudio, xcode
           scripts
              makefile.*
              *.def (module definition files)
@@ -136,11 +139,7 @@ Your directory structure should look like this:
           pngtest.png
           etc.
       zlib
-          README
-          *.h
-          *.c
-          contrib
-          etc.
+          README, *.h, *.c contrib, etc.
 
 If the line endings in the files look funny, you may wish to get the other
 distribution of libpng.  It is available in both tar.gz (UNIX style line
@@ -149,7 +148,7 @@ endings) and zip (DOS style line endings) formats.
 VI. Building with project files
 
 If you are building libpng with MSVC, you can enter the
-libpng projects\visualc6 or visualc71 directory and follow the instructions
+libpng projects\visualc71 or vstudio directory and follow the instructions
 in README.txt.
 
 Otherwise enter the zlib directory and follow the instructions in zlib/README,
@@ -190,7 +189,7 @@ run "make install".
 VIII. Configuring libpng for 16-bit platforms
 
 You will want to look into zconf.h to tell zlib (and thus libpng) that
-it cannot allocate more then 64K at a time.  Even if you can, the memory
+it cannot allocate more than 64K at a time.  Even if you can, the memory
 won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
 
 IX. Configuring for DOS
@@ -333,7 +332,7 @@ built.  pngconf.h no longer includes pngusr.h; therefore, pngusr.h is ignored
 after the build of pnglibconf.h and it is never included in an application
 build.
 
-The rarely used alternative of adding a list of feature macros to the
+The formerly used alternative of adding a list of feature macros to the
 CPPFLAGS setting in the build also still works; however, the macros will be
 copied to pnglibconf.h and this may produce macro redefinition warnings
 when the individual C files are compiled.
@@ -349,14 +348,21 @@ functioning awk called 'nawk'.
 
 Configuration options are now documented in scripts/pnglibconf.dfa.  This
 file also includes dependency information that ensures a configuration is
-consistent; that is, if a feature is switched off dependent features are
-also removed.  As a recommended alternative to using feature macros in
+consistent; that is, if a feature is switched off, dependent features are
+also switched off.  As a recommended alternative to using feature macros in
 pngusr.h a system builder may also define equivalent options in pngusr.dfa
 (or, indeed, any file) and add that to the configuration by setting
 DFA_XTRA to the file name.  The makefiles in contrib/pngminim illustrate
-how to do this, and illustrate a case where pngusr.h is still required.
+how to do this, and also illustrate a case where pngusr.h is still required.
 
-XV. Configuring libpng for multiprocessing
+After you have built libpng, the definitions that were recorded in
+pnglibconf.h are available to your application (pnglibconf.h is included
+in png.h and gets installed alongside png.h and pngconf.h in your
+$PREFIX/include directory).  Do not edit pnglibconf.h after you have built
+libpng, because than the settings would not accurately reflect the settings
+that were used to build libpng.
+
+XV. Setjmp/longjmp issues
 
 Libpng uses setjmp()/longjmp() for error handling.  Unfortunately setjmp()
 is known to be not thread-safe on some platforms and we don't know of
@@ -369,6 +375,11 @@ configure libpng with PNG_NO_SETJMP in your pngusr.dfa file, with
 
 in your pnglibconf.h or pngusr.h.
 
+Starting with libpng-1.6.0, the library included a "simplified API".
+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:
 
 Further information can be found in the README and libpng-manual.txt
@@ -388,7 +399,7 @@ CFLAGS="-Wall -O -funroll-loops \
 --with-pkgconfigdir=/usr/lib/pkgconfig --includedir=/usr/include
 
 You can alternatively specify --includedir=/usr/include, /usr/local/include,
-/usr/include/libpng%NN%, or whatever.
+/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",

LICENSE

@@ -10,8 +10,8 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.13, August 21, 2014, are
-Copyright (c) 2004, 2006-2014 Glenn Randers-Pehrson, and are
+libpng versions 1.2.6, August 15, 2004, through 1.6.18beta05, May 31, 2015, are
+Copyright (c) 2004, 2006-2015 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
 
@@ -108,4 +108,4 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-August 21, 2014
+May 31, 2015

Makefile.am

@@ -129,11 +129,12 @@ EXTRA_DIST= \
 	$(TESTS) $(XFAIL_TESTS) tests/pngstest \
 	CMakeLists.txt example.c libpng-manual.txt
 
-SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk scripts/pnglibconf.dfn
+SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk
 
 CLEANFILES= *.tf? pngout.png libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc \
 	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config libpng.vers libpng.sym \
-	check.new pnglibconf.* pngprefix.h symbols.new pngtest-log.txt \
+	check.new pnglibconf.h pngprefix.h symbols.new pngtest-log.txt \
+	pnglibconf.out pnglibconf.c pnglibconf.pre pnglibconf.dfn \
 	$(SCRIPT_CLEANFILES)
 
 MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess config.h.in \
@@ -152,7 +153,7 @@ AM_CFLAGS = ${PNG_COPTS}
 # checks for this and sets DFNCPP appropriately.
 DFNCPP = @DFNCPP@
 
-SUFFIXES = .chk .dfn .out
+SUFFIXES = .chk .out
 
 $(PNGLIB_BASENAME).pc: libpng.pc
 	cp libpng.pc $@
@@ -237,18 +238,17 @@ if DO_PNG_PREFIX
 SYMBOL_CFLAGS += -DPNG_PREFIX='@PNG_PREFIX@'
 endif
 
-.dfn.out:
-	rm -f $@ $*.c $*.tf[12]
+.c.out:
+	rm -f $@ $*.tf[12]
 	test -d scripts || mkdir scripts || test -d scripts
-	echo '#include "$<"' >$*.c
 	$(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)\
-	    $(CPPFLAGS) $(SYMBOL_CFLAGS) $*.c > $*.tf1
+	    $(CPPFLAGS) $(SYMBOL_CFLAGS) $< > $*.tf1
 	$(AWK) -f "${srcdir}/scripts/dfn.awk" out="$*.tf2" $*.tf1 1>&2
-	rm -f $*.c $*.tf1
+	rm -f $*.tf1
 	mv $*.tf2 $@
 
-# The .dfn file for pnglibconf.h is machine generated
-pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h pngusr.dfa $(DFA_XTRA)
+# The .c file for pnglibconf.h is machine generated
+pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h pngusr.dfa $(DFA_XTRA)
 	rm -f $@ $*.tf[45]
 	$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf4 version=search\
 	    ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
@@ -268,7 +268,7 @@ scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.ou
 
 # used on demand to regenerate the standard header, CPPFLAGS should
 # be empty - no non-standard defines
-scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
+scripts/pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
 	rm -f $@ pnglibconf.tf[67]
 	test -z "$(CPPFLAGS)"
 	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\

README

@@ -1,4 +1,4 @@
-README for libpng version 1.6.13 - August 21, 2014 (shared library 16.0)
+README for libpng version 1.6.18beta05 - May 31, 2015 (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.
@@ -23,18 +23,25 @@ earlier versions if you are using a shared library.  The type of the
 png_uint_32, which will affect shared-library applications that use
 this function.
 
-To avoid problems with changes to the internals of png_info_struct,
+To avoid problems with changes to the internals of png info_struct,
 new APIs have been made available in 0.95 to avoid direct application
 access to info_ptr.  These functions are the png_set_<chunk> and
 png_get_<chunk> functions.  These functions should be used when
 accessing/storing the info_struct data, rather than manipulating it
 directly, to avoid such problems in the future.
 
-It is important to note that the APIs do not make current programs
+It is important to note that the APIs did not make current programs
 that access the info struct directly incompatible with the new
-library.  However, it is strongly suggested that new programs use
-the new APIs (as shown in example.c and pngtest.c), and older programs
-be converted to the new format, to facilitate upgrades in the future.
+library, through libpng-1.2.x.  In libpng-1.4.x, which was meant to
+be a transitional release, members of the png_struct and the
+info_struct can still be accessed, but the compiler will issue a
+warning about deprecated usage.  Since libpng-1.5.0, direct access
+to these structs is not allowed, and the definitions of the structs
+reside in private pngstruct.h and pnginfo.h header files that are not
+accessible to applications.  It is strongly suggested that new
+programs use the new APIs (as shown in example.c and pngtest.c), and
+older programs be converted to the new format, to facilitate upgrades
+in the future.
 ****
 
 Additions since 0.90 include the ability to compile libpng as a
@@ -127,7 +134,7 @@ and ...".  If in doubt, send questions to me.  I'll bounce them
 to others, if necessary.
 
 Please do not send suggestions on how to change PNG.  We have
-been discussing PNG for nineteen years now, and it is official and
+been discussing PNG for twenty years now, and it is official and
 finished.  If you have suggestions for libpng, however, I'll
 gladly listen.  Even if your suggestion is not used immediately,
 it may be used later.
@@ -183,7 +190,7 @@ Files in this distribution:
        pngminus         =>  Simple pnm2png and png2pnm programs
        pngsuite         =>  Test images
        tools            =>  Various tools
-       visupng      =>  Contains a MSVC workspace for VisualPng
+       visupng          =>  Contains a MSVC workspace for VisualPng
       projects      =>  Contains project files and workspaces for
                         building a DLL
        owatcom          =>  Contains a WATCOM project for building libpng

arm/arm_init.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -17,6 +17,7 @@
 #include "../pngpriv.h"
 
 #ifdef PNG_READ_SUPPORTED
+
 #if PNG_ARM_NEON_OPT > 0
 #ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
 /* WARNING: it is strongly recommended that you do not build libpng with
@@ -130,4 +131,4 @@ png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
    }
 }
 #endif /* PNG_ARM_NEON_OPT > 0 */
-#endif /* PNG_READ_SUPPORTED */
+#endif /* READ */

arm/filter_neon.S

@@ -1,18 +1,17 @@
 
 /* filter_neon.S - NEON optimised filter functions
  *
- * Copyright (c) 2013 Glenn Randers-Pehrson
+ * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.8 [December 19, 2013]
+ * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  */
 
-/* This is required to get the symbol renames, which are #defines, and also
- * includes the definition (or not) of PNG_ARM_NEON_OPT and
- * PNG_ARM_NEON_IMPLEMENTATION.
+/* This is required to get the symbol renames, which are #defines, and the
+ * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION.
  */
 #define PNG_VERSION_INFO_ONLY
 #include "../pngpriv.h"
@@ -21,6 +20,8 @@
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
 
+#ifdef PNG_READ_SUPPORTED
+
 /* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for
  * ARM64).  The code in arm/filter_neon_intrinsics.c supports ARM64, however it
  * only works if -mfpu=neon is specified on the GCC command line.  See pngpriv.h
@@ -28,7 +29,6 @@
  */
 #if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
 
-#ifdef PNG_READ_SUPPORTED
 #if PNG_ARM_NEON_OPT > 0
 
 #ifdef __ELF__
@@ -47,6 +47,13 @@ ELF     .size   \name, . - \name
         .purgem endfunc
     .endm
         .text
+
+        /* Explicitly specifying alignment here because some versions of
+         * GAS don't align code correctly.  This is harmless in correctly
+         * written versions of GAS.
+         */
+        .align 2
+
     .if \export
         .global \name
     .endif
@@ -242,5 +249,5 @@ func    png_read_filter_row_paeth3_neon, export=1
         pop             {r4,pc}
 endfunc
 #endif /* PNG_ARM_NEON_OPT > 0 */
-#endif /* PNG_READ_SUPPORTED */
 #endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */
+#endif /* READ */

arm/filter_neon_intrinsics.c

@@ -1,11 +1,11 @@
 
 /* filter_neon_intrinsics.c - NEON optimised filter functions
  *
- * Copyright (c) 2013 Glenn Randers-Pehrson
+ * Copyright (c) 2014 Glenn Randers-Pehrson
  * 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 1.6.8 [December 19, 2013]
+ * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -14,6 +14,8 @@
 
 #include "../pngpriv.h"
 
+#ifdef PNG_READ_SUPPORTED
+
 /* This code requires -mfpu=neon on the command line: */
 #if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
 
@@ -35,7 +37,6 @@
 #define png_ldr(type,pointer)\
    (temp_pointer = png_ptr(type,pointer), *temp_pointer)
 
-#ifdef PNG_READ_SUPPORTED
 #if PNG_ARM_NEON_OPT > 0
 
 void
@@ -368,5 +369,5 @@ png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
 }
 
 #endif /* PNG_ARM_NEON_OPT > 0 */
-#endif /* PNG_READ_SUPPORTED */
 #endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */
+#endif /* READ */

autogen.sh

@@ -73,8 +73,9 @@ done
 # present bad things are happening.
 #
 # The autotools generated files:
-libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in\
-   config.sub configure depcomp install-sh ltmain.sh missing test-driver"
+libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in
+   config.h.in~ config.sub configure depcomp install-sh ltmain.sh missing\
+   test-driver"
 #
 # Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
 # versions than those required by configure.ac):

configure.ac

@@ -18,7 +18,7 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.13],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.18beta05],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -39,10 +39,10 @@ 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=1.6.13
+PNGLIB_VERSION=1.6.18beta05
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=13
+PNGLIB_RELEASE=18
 
 dnl End of version number stuff
 
@@ -310,7 +310,7 @@ AC_ARG_ENABLE([arm-neon],
 AM_CONDITIONAL([PNG_ARM_NEON],
    [test "$enable_arm_neon" != 'no' &&
     case "$host_cpu" in
-      arm*) :;;
+      arm*|aarch64*) :;;
       *)    test "$enable_arm_neon" != '';;
     esac])
 

contrib/arm-neon/linux.c

@@ -2,7 +2,7 @@
  *
  * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by John Bowler, 2014.
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -16,8 +16,8 @@
  * png_have_neon implemented for Linux by reading the widely available
  * pseudo-file /proc/cpuinfo.
  *
- * This code is strict ANSI-C and is probably moderately portable, it does
- * however use <stdio.h> and assumes that /proc/cpuinfo is never localized.
+ * This code is strict ANSI-C and is probably moderately portable; it does
+ * however use <stdio.h> and it assumes that /proc/cpuinfo is never localized.
  */
 #include <stdio.h>
 
@@ -152,8 +152,10 @@ png_have_neon(png_structp png_ptr)
       }
    }
 
+#ifdef PNG_WARNINGS_SUPPORTED
    else
       png_warning(png_ptr, "/proc/cpuinfo open failed");
+#endif
 
    return 0;
 }

contrib/examples/simpleover.c

@@ -0,0 +1,645 @@
+/*- simpleover
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2015.
+ * 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.
+ *
+ * Read several PNG files, which should have an alpha channel or transparency
+ * information, and composite them together to produce one or more 16-bit linear
+ * RGBA intermediates.  This involves doing the correct 'over' composition to
+ * combine the alpha channels and corresponding data.
+ *
+ * Finally read an output (background) PNG using the 24-bit RGB format (the
+ * PNG will be composited on green (#00ff00) by default if it has an alpha
+ * channel), and apply the intermediate image generated above to specified
+ * locations in the image.
+ *
+ * The command line has the general format:
+ *
+ *    simpleover <background.png> [output.png]
+ *        {--sprite=width,height,name {[--at=x,y] {sprite.png}}}
+ *        {--add=name {x,y}}
+ *
+ * The --sprite and --add options may occur multiple times. They are executed
+ * in order.  --add may refer to any sprite already read.
+ *
+ * This code is intended to show how to composite multiple images together
+ * correctly.  Apart from the libpng Simplified API the only work done in here
+ * is to combine multiple input PNG images into a single sprite; this involves
+ * a Porter-Duff 'over' operation and the input PNG images may, as a result,
+ * be regarded as being layered one on top of the other with the first (leftmost
+ * on the command line) being at the bottom and the last on the top.
+ */
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+
+/* Normally use <png.h> here to get the installed libpng, but this is done to
+ * ensure the code picks up the local libpng implementation, so long as this
+ * file is linked against a sufficiently recent libpng (1.6+) it is ok to
+ * change this to <png.h>:
+ */
+#include "../../png.h"
+
+#define sprite_name_chars 15
+struct sprite {
+   FILE         *file;
+   png_uint_16p  buffer;
+   unsigned int  width;
+   unsigned int  height;
+   char          name[sprite_name_chars+1];
+};
+
+#if 0 /* div by 65535 test program */
+#include <math.h>
+#include <stdio.h>
+
+int main(void) {
+   double err = 0;
+   unsigned int xerr = 0;
+   unsigned int r = 32769;
+   {
+      unsigned int x = 0;
+
+      do {
+         unsigned int t = x + (x >> 16) /*+ (x >> 31)*/ + r;
+         double v = x, errtest;
+
+         if (t < x) {
+            fprintf(stderr, "overflow: %u+%u -> %u\n", x, r, t);
+            return 1;
+         }
+
+         v /= 65535;
+         errtest = v;
+         t >>= 16;
+         errtest -= t;
+
+         if (errtest > err) {
+            err = errtest;
+            xerr = x;
+
+            if (errtest >= .5) {
+               fprintf(stderr, "error: %u/65535 = %f, not %u, error %f\n",
+                     x, v, t, errtest);
+               return 0;
+            }
+         }
+      } while (++x <= 65535U*65535U);
+   }
+
+   printf("error %f @ %u\n", err, xerr);
+
+   return 0;
+}
+#endif /* div by 65535 test program */
+
+static void
+sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
+   png_imagep image, const png_uint_16 *buffer)
+{
+   /* This is where the Porter-Duff 'Over' operator is evaluated; change this
+    * code to change the operator (this could be parameterized).  Any other
+    * image processing operation could be used here.
+    */
+
+
+   /* Check for an x or y offset that pushes any part of the image beyond the
+    * right or bottom of the sprite:
+    */
+   if ((y_offset < 0 || (unsigned)/*SAFE*/y_offset < sprite->height) &&
+       (x_offset < 0 || (unsigned)/*SAFE*/x_offset < sprite->width))
+   {
+      unsigned int y = 0;
+
+      if (y_offset < 0)
+         y = -y_offset; /* Skip to first visible row */
+
+      do
+      {
+         unsigned int x = 0;
+
+         if (x_offset < 0)
+            x = -x_offset;
+
+         do
+         {
+            /* In and out are RGBA values, so: */
+            const png_uint_16 *in_pixel = buffer + (y * image->width + x)*4;
+            png_uint_32 in_alpha = in_pixel[3];
+
+            /* This is the optimized Porter-Duff 'Over' operation, when the
+             * input alpha is 0 the output is not changed.
+             */
+            if (in_alpha > 0) 
+            {
+               png_uint_16 *out_pixel = sprite->buffer +
+                  ((y+y_offset) * sprite->width + (x+x_offset))*4;
+
+               /* This is the weight to apply to the output: */
+               in_alpha = 65535-in_alpha;
+
+               if (in_alpha > 0)
+               {
+                  /* The input must be composed onto the output. This means
+                   * multiplying the current output pixel value by the inverse
+                   * of the input alpha (1-alpha). A division is required but
+                   * it is by the constant 65535.  Approximate this as:
+                   *
+                   *     (x + (x >> 16) + 32769) >> 16;
+                   *
+                   * This is exact (and does not overflow) for all values of
+                   * x in the range 0..65535*65535.  (Note that the calculation
+                   * produces the closest integer; the maximum error is <0.5).
+                   */
+                  png_uint_32 tmp;
+
+#                 define compose(c)\
+                     tmp = out_pixel[c] * in_alpha;\
+                     tmp = (tmp + (tmp >> 16) + 32769) >> 16;\
+                     out_pixel[c] = tmp + in_pixel[c]
+
+                  /* The following is very vectorizable... */
+                  compose(0);
+                  compose(1);
+                  compose(2);
+                  compose(3);
+               }
+
+               else
+                  out_pixel[0] = in_pixel[0],
+                  out_pixel[1] = in_pixel[1],
+                  out_pixel[2] = in_pixel[2],
+                  out_pixel[3] = in_pixel[3];
+            }
+         }
+         while (++x < image->width);
+      }
+      while (++y < image->height);
+   }
+}
+
+static int 
+create_sprite(struct sprite *sprite, int *argc, const char ***argv)
+{
+   /* Read the arguments and create this sprite. The sprite buffer has already
+    * been allocated. This reads the input PNGs one by one in linear format,
+    * composes them onto the sprite buffer (the code in the function above)
+    * then saves the result, converting it on the fly to PNG RGBA 8-bit format.
+    */
+   while (*argc > 0)
+   {
+      char tombstone;
+      int x = 0, y = 0;
+
+      if ((*argv)[0][0] == '-' && (*argv)[0][1] == '-')
+      {
+         /* The only supported option is --at. */
+         if (sscanf((*argv)[0], "--at=%d,%d%c", &x, &y, &tombstone) != 2)
+            break; /* success; caller will parse this option */
+
+         ++*argv, --*argc;
+      }
+
+      else
+      {
+         /* The argument has to be a file name */
+         png_image image;
+
+         image.version = PNG_IMAGE_VERSION;
+         image.opaque = NULL;
+
+         if (png_image_begin_read_from_file(&image, (*argv)[0]))
+         {
+            png_uint_16p buffer;
+
+            image.format = PNG_FORMAT_LINEAR_RGB_ALPHA;
+
+            buffer = malloc(PNG_IMAGE_SIZE(image));
+
+            if (buffer != NULL)
+            {
+               if (png_image_finish_read(&image, NULL/*background*/, buffer,
+                  0/*row_stride*/,
+                  NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP*/))
+               {
+                  /* This is the place where the Porter-Duff 'Over' operator
+                   * needs to be done by this code.  In fact, any image
+                   * processing required can be done here; the data is in
+                   * the correct format (linear, 16-bit) and source and
+                   * destination are in memory.
+                   */
+                  sprite_op(sprite, x, y, &image, buffer);
+                  free(buffer);
+                  ++*argv, --*argc;
+                  /* And continue to the next argument */
+                  continue;
+               }
+
+               else
+               {
+                  free(buffer);
+                  fprintf(stderr, "simpleover: read %s: %s\n", (*argv)[0],
+                      image.message);
+               }
+            }
+
+            else
+            {
+               fprintf(stderr, "simpleover: out of memory: %lu bytes\n",
+                  (unsigned long)PNG_IMAGE_SIZE(image));
+
+               /* png_image_free must be called if we abort the Simplified API
+                * read because of a problem detected in this code.  If problems
+                * are detected in the Simplified API it cleans up itself.
+                */
+               png_image_free(&image);
+            }
+         }
+
+         else
+         {
+            /* Failed to read the first argument: */
+            fprintf(stderr, "simpleover: %s: %s\n", (*argv)[0], image.message);
+         }
+
+         return 0; /* failure */
+      }
+   }
+
+   /* All the sprite operations have completed successfully. Save the RGBA
+    * buffer as a PNG using the simplified write API.
+    */
+   sprite->file = tmpfile();
+
+   if (sprite->file != NULL)
+   {
+      png_image save;
+
+      memset(&save, 0, sizeof save);
+      save.version = PNG_IMAGE_VERSION;
+      save.opaque = NULL;
+      save.width = sprite->width;
+      save.height = sprite->height;
+      save.format = PNG_FORMAT_LINEAR_RGB_ALPHA;
+      save.flags = PNG_IMAGE_FLAG_FAST;
+      save.colormap_entries = 0;
+
+      if (png_image_write_to_stdio(&save, sprite->file, 1/*convert_to_8_bit*/,
+          sprite->buffer, 0/*row_stride*/, NULL/*colormap*/))
+      {
+         /* Success; the buffer is no longer needed: */
+         free(sprite->buffer);
+         sprite->buffer = NULL;
+         return 1; /* ok */
+      }
+
+      else
+         fprintf(stderr, "simpleover: write sprite %s: %s\n", sprite->name,
+            save.message);
+   }
+
+   else
+      fprintf(stderr, "simpleover: sprite %s: could not allocate tmpfile: %s\n",
+         sprite->name, strerror(errno));
+
+   return 0; /* fail */
+}
+
+static int
+add_sprite(png_imagep output, png_bytep out_buf, struct sprite *sprite,
+   int *argc, const char ***argv)
+{
+   /* Given a --add argument naming this sprite, perform the operations listed
+    * in the following arguments.  The arguments are expected to have the form
+    * (x,y), which is just an offset at which to add the sprite to the
+    * output.
+    */
+   while (*argc > 0)
+   {
+      char tombstone;
+      int x, y;
+
+      if ((*argv)[0][0] == '-' && (*argv)[0][1] == '-')
+         return 1; /* success */
+
+      if (sscanf((*argv)[0], "%d,%d%c", &x, &y, &tombstone) == 2)
+      {
+         /* Now add the new image into the sprite data, but only if it
+          * will fit.
+          */
+         if (x < 0 || y < 0 ||
+             (unsigned)/*SAFE*/x >= output->width ||
+             (unsigned)/*SAFE*/y >= output->height ||
+             sprite->width > output->width-x ||
+             sprite->height > output->height-y)
+         {
+            fprintf(stderr, "simpleover: sprite %s @ (%d,%d) outside image\n",
+               sprite->name, x, y);
+            /* Could just skip this, but for the moment it is an error */
+            return 0; /* error */
+         }
+
+         else
+         {
+            /* Since we know the sprite fits we can just read it into the
+             * output using the simplified API.
+             */
+            png_image in;
+
+            in.version = PNG_IMAGE_VERSION;
+            rewind(sprite->file);
+
+            if (png_image_begin_read_from_stdio(&in, sprite->file))
+            {
+               in.format = PNG_FORMAT_RGB; /* force compose */
+
+               if (png_image_finish_read(&in, NULL/*background*/,
+                  out_buf + (y*output->width + x)*3/*RGB*/,
+                  output->width*3/*row_stride*/,
+                  NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP*/))
+               {
+                  ++*argv, --*argc;
+                  continue;
+               }
+            }
+
+            /* The read failed: */
+            fprintf(stderr, "simpleover: add sprite %s: %s\n", sprite->name,
+                in.message);
+            return 0; /* error */
+         }
+      }
+
+      else
+      {
+         fprintf(stderr, "simpleover: --add='%s': invalid position %s\n",
+               sprite->name, (*argv)[0]);
+         return 0; /* error */
+      }
+   }
+
+   return 1; /* ok */
+}
+
+static int
+simpleover_process(png_imagep output, png_bytep out_buf, int argc,
+   const char **argv)
+{
+   int result = 1; /* success */
+#  define csprites 10/*limit*/
+#  define str(a) #a
+   int nsprites = 0;
+   struct sprite sprites[csprites];
+
+   while (argc > 0)
+   {
+      result = 0; /* fail */
+
+      if (strncmp(argv[0], "--sprite=", 9) == 0)
+      {
+         char tombstone;
+
+         if (nsprites < csprites)
+         {
+            int n;
+
+            sprites[nsprites].width = sprites[nsprites].height = 0;
+            sprites[nsprites].name[0] = 0;
+
+            n = sscanf(argv[0], "--sprite=%u,%u,%" str(sprite_name_chars) "s%c",
+                &sprites[nsprites].width, &sprites[nsprites].height,
+                sprites[nsprites].name, &tombstone);
+            
+            if ((n == 2 || n == 3) &&
+                sprites[nsprites].width > 0 && sprites[nsprites].height > 0)
+            {
+               size_t buf_size, tmp;
+
+               /* Default a name if not given. */
+               if (sprites[nsprites].name[0] == 0)
+                  sprintf(sprites[nsprites].name, "sprite-%d", nsprites+1);
+
+               /* Allocate a buffer for the sprite and calculate the buffer
+                * size:
+                */
+               buf_size = sizeof (png_uint_16 [4]);
+               buf_size *= sprites[nsprites].width;
+               buf_size *= sprites[nsprites].height;
+
+               /* This can overflow a (size_t); check for this: */
+               tmp = buf_size;
+               tmp /= sprites[nsprites].width;
+               tmp /= sprites[nsprites].height;
+
+               if (tmp == sizeof (png_uint_16 [4]))
+               {
+                  sprites[nsprites].buffer = malloc(buf_size);
+                  /* This buffer must be initialized to transparent: */
+                  memset(sprites[nsprites].buffer, 0, buf_size);
+
+                  if (sprites[nsprites].buffer != NULL)
+                  {
+                     sprites[nsprites].file = NULL;
+                     ++argv, --argc;
+
+                     if (create_sprite(sprites+nsprites++, &argc, &argv))
+                     {
+                        result = 1; /* still ok */
+                        continue;
+                     }
+
+                     break; /* error */
+                  }
+               }
+
+               /* Overflow, or OOM */
+               fprintf(stderr, "simpleover: %s: sprite too large\n", argv[0]);
+               break;
+            }
+
+            else
+            {
+               fprintf(stderr, "simpleover: %s: invalid sprite (%u,%u)\n",
+                  argv[0], sprites[nsprites].width, sprites[nsprites].height);
+               break;
+            }
+         }
+
+         else
+         {
+            fprintf(stderr, "simpleover: %s: too many sprites\n", argv[0]);
+            break;
+         }
+      }
+
+      else if (strncmp(argv[0], "--add=", 6) == 0)
+      {
+         const char *name = argv[0]+6;
+         int isprite = nsprites;
+
+         ++argv, --argc;
+
+         while (--isprite >= 0)
+         {
+            if (strcmp(sprites[isprite].name, name) == 0)
+            {
+               if (!add_sprite(output, out_buf, sprites+isprite, &argc, &argv))
+                  goto out; /* error in add_sprite */
+
+               break; 
+            }
+         }
+
+         if (isprite < 0) /* sprite not found */
+         {
+            fprintf(stderr, "simpleover: --add='%s': sprite not found\n", name);
+            break;
+         }
+      }
+
+      else
+      {
+         fprintf(stderr, "simpleover: %s: unrecognized operation\n", argv[0]);
+         break;
+      }
+
+      result = 1; /* ok  */
+   }
+
+   /* Clean up the cache of sprites: */
+out:
+   while (--nsprites >= 0)
+   {
+      if (sprites[nsprites].buffer != NULL)
+         free(sprites[nsprites].buffer);
+
+      if (sprites[nsprites].file != NULL)
+         (void)fclose(sprites[nsprites].file);
+   }
+
+   return result;
+}
+
+int main(int argc, const char **argv)
+{
+   int result = 1; /* default to fail */
+
+   if (argc >= 2)
+   {
+      int argi = 2;
+      const char *output = NULL;
+      png_image image;
+
+      if (argc > 2 && argv[2][0] != '-'/*an operation*/)
+      {
+         output = argv[2];
+         argi = 3;
+      }
+
+      image.version = PNG_IMAGE_VERSION;
+      image.opaque = NULL;
+
+      if (png_image_begin_read_from_file(&image, argv[1]))
+      {
+         png_bytep buffer;
+
+         image.format = PNG_FORMAT_RGB; /* 24-bit RGB */
+
+         buffer = malloc(PNG_IMAGE_SIZE(image));
+
+         if (buffer != NULL)
+         {
+            png_color background = {0, 0xff, 0}; /* fully saturated green */
+
+            if (png_image_finish_read(&image, &background, buffer,
+               0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */))
+            {
+               /* At this point png_image_finish_read has cleaned up the
+                * allocated data in png_image, and only the buffer needs to be
+                * freed.
+                *
+                * Perform the remaining operations:
+                */
+               if (simpleover_process(&image, buffer, argc-argi, argv+argi))
+               {
+                  /* Write the output: */
+                  if ((output != NULL &&
+                       png_image_write_to_file(&image, output,
+                        0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
+                        NULL/*colormap*/)) ||
+                      (output == NULL &&
+                       png_image_write_to_stdio(&image, stdout,
+                        0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
+                        NULL/*colormap*/)))
+                     result = 0;
+
+                  else
+                     fprintf(stderr, "simpleover: write %s: %s\n",
+                        output == NULL ? "stdout" : output, image.message);
+               }
+
+               /* else simpleover_process writes an error message */
+            }
+
+            else
+               fprintf(stderr, "simpleover: read %s: %s\n", argv[1],
+                   image.message);
+
+            free(buffer);
+         }
+
+         else
+         {
+            fprintf(stderr, "simpleover: out of memory: %lu bytes\n",
+               (unsigned long)PNG_IMAGE_SIZE(image));
+
+            /* This is the only place where a 'free' is required; libpng does
+             * the cleanup on error and success, but in this case we couldn't
+             * complete the read because of running out of memory.
+             */
+            png_image_free(&image);
+         }
+      }
+
+      else
+      {
+         /* Failed to read the first argument: */
+         fprintf(stderr, "simpleover: %s: %s\n", argv[1], image.message);
+      }
+   }
+
+   else
+   {
+      /* Usage message */
+      fprintf(stderr,
+         "simpleover: usage: simpleover background.png [output.png]\n"
+         "  Output 'background.png' as a 24-bit RGB PNG file in 'output.png'\n"
+         "   or, if not given, stdout.  'background.png' will be composited\n"
+         "   on fully saturated green.\n"
+         "\n"
+         "  Optionally, before output, process additional PNG files:\n"
+         "\n"
+         "   --sprite=width,height,name {[--at=x,y] {sprite.png}}\n"
+         "    Produce a transparent sprite of size (width,height) and with\n"
+         "     name 'name'.\n"
+         "    For each sprite.png composite it using a Porter-Duff 'Over'\n"
+         "     operation at offset (x,y) in the sprite (defaulting to (0,0)).\n"
+         "     Input PNGs will be truncated to the area of the sprite.\n"
+         "\n"
+         "   --add='name' {x,y}\n"
+         "    Optionally, before output, composite a sprite, 'name', which\n"
+         "     must have been previously produced using --sprite, at each\n"
+         "     offset (x,y) in the output image.  Each sprite must fit\n"
+         "     completely within the output image.\n"
+         "\n"
+         "  PNG files are processed in the order they occur on the command\n"
+         "  line and thus the first PNG processed appears as the bottommost\n"
+         "  in the output image.\n");
+   }
+
+   return result;
+}

contrib/gregbook/readpng.c

@@ -100,7 +100,8 @@ int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
 
     /* could pass pointers to user-defined error handlers instead of NULLs: */
 
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), NULL, NULL,
+        NULL);
     if (!png_ptr)
         return 4;   /* out of memory */
 

contrib/gregbook/readpng2.c

@@ -104,7 +104,7 @@ int readpng2_init(mainprog_info *mainprog_ptr)
 
     /* could also replace libpng warning-handler (final NULL), but no need: */
 
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), mainprog_ptr,
       readpng2_error_handler, readpng2_warning_handler);
     if (!png_ptr)
         return 4;   /* out of memory */

contrib/gregbook/rpng2-x.c

@@ -103,9 +103,6 @@
 #define RESNAME   "rpng2"       /* our X resource application name */
 #define RESCLASS  "Rpng"       /* our X resource class name */
 
-/* This is temporary until the code is rewritten to use nanosleep(). */
-#define usleep(x) sleep(((x)+499999)/1000000)
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
@@ -118,6 +115,18 @@
 #include <X11/Xos.h>
 #include <X11/keysym.h>   /* defines XK_* macros */
 
+#if _POSIX_C_SOURCE >= 199309L /* have nanosleep() */
+# undef usleep
+# define usleep(usec) {        \
+   struct timespec ts;         \
+   ts.tv_nsec = (usec) * 1000; \
+   nanosleep(&ts, NULL); }
+#  endif
+
+#ifndef usleep /* have neither nanosleep() nor usleep() */
+#  define usleep(x) sleep(((x)+499999)/1000000)
+#endif
+
 #ifdef VMS
 #  include <unistd.h>
 #endif

contrib/gregbook/writepng.c

@@ -90,7 +90,7 @@ int writepng_init(mainprog_info *mainprog_ptr)
 
     /* could also replace libpng warning-handler (final NULL), but no need: */
 
-    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+    png_ptr = png_create_write_struct(png_get_libpng_ver(NULL), mainprog_ptr,
       writepng_error_handler, NULL);
     if (!png_ptr)
         return 4;   /* out of memory */

contrib/libtests/fakepng.c

@@ -52,6 +52,6 @@ main(void)
    fwrite(signature, sizeof signature, 1, stdout);
    put_chunk(IHDR, sizeof IHDR);
 
-   for(;;)
+   for (;;)
       put_chunk(unknown, sizeof unknown);
 }

contrib/libtests/pngimage.c

@@ -337,6 +337,9 @@ validate_T(void)
  *    In both cases the file data is held in a linked list of buffers - not all
  *    of these are in use at any time.
  */
+#define NEW(type) ((type *)malloc(sizeof (type)))
+#define DELETE(ptr) (free(ptr))
+
 struct buffer_list
 {
    struct buffer_list *next;         /* next buffer in list */
@@ -361,6 +364,25 @@ buffer_init(struct buffer *buffer)
    buffer->current = NULL;
 }
 
+static void
+buffer_destroy_list(struct buffer_list *list)
+{
+   if (list != NULL)
+   {
+      struct buffer_list *next = list->next;
+      DELETE(list);
+      buffer_destroy_list(next);
+   }
+}
+
+static void
+buffer_destroy(struct buffer *buffer)
+{
+   struct buffer_list *list = buffer->first.next;
+   buffer_init(buffer);
+   buffer_destroy_list(list);
+}
+
 #ifdef PNG_WRITE_SUPPORTED
 static void
 buffer_start_write(struct buffer *buffer)
@@ -390,8 +412,6 @@ get_buffer(png_structp pp)
    return (struct buffer*)png_get_io_ptr(pp);
 }
 
-#define NEW(type) ((type *)malloc(sizeof (type)))
-
 static struct buffer_list *
 buffer_extend(struct buffer_list *current)
 {
@@ -598,6 +618,17 @@ display_clean(struct display *dp)
    dp->results = 0; /* reset for next time */
 }
 
+static void
+display_destroy(struct display *dp)
+{
+    /* Release any memory held in the display. */
+#  ifdef PNG_WRITE_SUPPORTED
+      buffer_destroy(&dp->written_file);
+#  endif
+
+   buffer_destroy(&dp->original_file);
+}
+
 static struct display *
 get_dp(png_structp pp)
    /* The display pointer is always stored in the png_struct error pointer */
@@ -1605,6 +1636,9 @@ main(const int argc, const char * const * const argv)
          display_clean(&d);
       }
 
+      /* Release allocated memory */
+      display_destroy(&d);
+
       return errors != 0;
    }
 }

contrib/libtests/pngstest.c

@@ -1,9 +1,9 @@
 /*-
  * pngstest.c
  *
- * Copyright (c) 2013 John Cunningham Bowler
+ * Copyright (c) 2013-2014 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.8 [December 19, 2013]
+ * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -3173,32 +3173,43 @@ read_one_file(Image *image)
             {
                long int cb = ftell(f);
 
-               if (cb > 0 && (unsigned long int)cb < (size_t)~(size_t)0)
+               if (cb > 0)
                {
-                  png_bytep b = voidcast(png_bytep, malloc((size_t)cb));
-
-                  if (b != NULL)
+                  if ((unsigned long int)cb <= (size_t)~(size_t)0)
                   {
-                     rewind(f);
+                     png_bytep b = voidcast(png_bytep, malloc((size_t)cb));
 
-                     if (fread(b, (size_t)cb, 1, f) == 1)
+                     if (b != NULL)
                      {
-                        fclose(f);
-                        image->input_memory_size = cb;
-                        image->input_memory = b;
+                        rewind(f);
+
+                        if (fread(b, (size_t)cb, 1, f) == 1)
+                        {
+                           fclose(f);
+                           image->input_memory_size = cb;
+                           image->input_memory = b;
+                        }
+
+                        else
+                        {
+                           free(b);
+                           return logclose(image, f, image->file_name,
+                              ": read failed: ");
+                        }
                      }
 
                      else
-                     {
-                        free(b);
                         return logclose(image, f, image->file_name,
-                           ": read failed: ");
-                     }
+                           ": out of memory: ");
                   }
 
                   else
                      return logclose(image, f, image->file_name,
-                        ": out of memory: ");
+                        ": file too big for this architecture: ");
+                     /* cb is the length of the file as a (long) and
+                      * this is greater than the maximum amount of
+                      * memory that can be requested from malloc.
+                      */
                }
 
                else if (cb == 0)

contrib/libtests/pngunknown.c

@@ -1242,4 +1242,4 @@ main(void)
    /* So the test is skipped: */
    return 77;
 }
-#endif /* SET_UNKNOWN_CHUNKS && READ*/
+#endif /* SET_UNKNOWN_CHUNKS && READ */

contrib/pngminus/png2pnm.c

@@ -223,7 +223,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
 
   /* create png and info structures */
 
-  png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
+  png_ptr = png_create_read_struct (png_get_libpng_ver(NULL),
     NULL, NULL, NULL);
   if (!png_ptr)
     return FALSE;   /* out of memory */

contrib/pngminus/pnm2png.c

@@ -425,7 +425,8 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   } /* end for row */
 
   /* prepare the standard PNG structures */
-  png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  png_ptr = png_create_write_struct (png_get_libpng_ver(NULL), NULL, NULL,
+      NULL);
   if (!png_ptr)
   {
     return FALSE;

contrib/tools/genpng.c

@@ -0,0 +1,864 @@
+/*- genpng
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2015.
+ * 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.
+ *
+ * Generate a PNG with an alpha channel, correctly.
+ *
+ * This is a test case generator; the resultant PNG files are only of interest
+ * to those of us who care about whether the edges of circles are green, red,
+ * or yellow.
+ *
+ * The program generates an RGB+Alpha PNG of a given size containing the given
+ * shapes on a transparent background:
+ *
+ *  genpng width height { shape }
+ *    shape ::= color width shape x1 y1 x2 y2
+ *
+ * 'color' is:
+ *
+ *  black white red green yellow blue brown purple pink orange gray cyan
+ *
+ * The point is to have colors that are linguistically meaningful plus that old
+ * bugbear of the department store dress murders, Cyan, the only color we argue
+ * about.
+ *
+ * 'shape' is:
+ *
+ *  circle: an ellipse
+ *  square: a rectangle
+ *  line: a straight line
+ *
+ * Each shape is followed by four numbers, these are two points in the output
+ * coordinate space (as real numbers) which describe the circle, square, or
+ * line.  The shape is filled if it is preceded by 'filled' (not valid for
+ * 'line') or is drawn with a line, in which case the width of the line must
+ * precede the shape.
+ *
+ * The whole set of information can be repeated as many times as desired:
+ *
+ *    shape ::= color width shape x1 y1 x2 y2
+ *
+ *    color ::= black|white|red|green|yellow|blue
+ *    color ::= brown|purple|pink|orange|gray|cyan
+ *    width ::= filled
+ *    width ::= <number>
+ *    shape ::= circle|square|line
+ *    x1    ::= <number>
+ *    x2    ::= <number>
+ *    y1    ::= <number>
+ *    y2    ::= <number>
+ *
+ * The output PNG is generated by down-sampling a 4x supersampled image using
+ * a bi-cubic filter.  The bi-cubic has a 2 (output) pixel width, so an 8x8
+ * array of super-sampled points contribute to each output pixel.  The value of
+ * a super-sampled point is found using an unfiltered, aliased, infinite
+ * precision image: Each shape from the last to the first is checked to see if
+ * the point is in the drawn area and, if it is, the color of the point is the
+ * color of the shape and the alpha is 1, if not the previous shape is checked.
+ *
+ * This is an aliased algorithm because no filtering is done; a point is either
+ * inside or outside each shape and 'close' points do not contribute to the
+ * sample.  The down-sampling is relied on to correct the error of not using
+ * a filter.
+ *
+ * The line end-caps are 'flat'; they go through the points.  The square line
+ * joins are mitres; the outside of the lines are continued to the point of
+ * intersection.
+ */
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <math.h>
+
+/* Normally use <png.h> here to get the installed libpng, but this is done to
+ * ensure the code picks up the local libpng implementation:
+ */
+#include "../../png.h"
+
+static const struct color
+{
+   const char *name;
+   double      red;
+   double      green;
+   double      blue;
+} colors[] =
+/* color ::= black|white|red|green|yellow|blue
+ * color ::= brown|purple|pink|orange|gray|cyan
+ */
+{
+   { "black",   0,    0,  0 },
+   { "white",   1,    1,  1 },
+   { "red",     1,    0,  0 },
+   { "green",   0,    1,  0 },
+   { "yellow",  1,    1,  0 },
+   { "blue",    0,    0,  1 },
+   { "brown",  .5, .125,  0 },
+   { "purple",  1,    0,  1 },
+   { "pink",    1,   .5, .5 },
+   { "orange",  1,   .5,  0 },
+   { "gray",    0,   .5, .5 },
+   { "cyan",    0,    1,  1 }
+};
+#define color_count ((sizeof colors)/(sizeof colors[0]))
+
+static const struct color *
+color_of(const char *arg)
+{
+   int icolor = color_count;
+
+   while (--icolor >= 0)
+   {
+      if (strcmp(colors[icolor].name, arg) == 0)
+         return colors+icolor;
+   }
+
+   fprintf(stderr, "genpng: invalid color %s\n", arg);
+   exit(1);
+}
+
+static double
+width_of(const char *arg)
+{
+   if (strcmp(arg, "filled") == 0)
+      return 0;
+
+   else
+   {
+      char *ep = NULL;
+      double w = strtod(arg, &ep);
+
+      if (ep != NULL && *ep == 0 && w > 0)
+         return w;
+   }
+
+   fprintf(stderr, "genpng: invalid line width %s\n", arg);
+   exit(1);
+}
+
+static double
+coordinate_of(const char *arg)
+{
+   char *ep = NULL;
+   double w = strtod(arg, &ep);
+
+   if (ep != NULL && *ep == 0)
+      return w;
+
+   fprintf(stderr, "genpng: invalid coordinate value %s\n", arg);
+   exit(1);
+}
+
+struct arg; /* forward declaration */
+
+typedef int (*shape_fn_ptr)(const struct arg *arg, double x, double y);
+   /* A function to determine if (x,y) is inside the shape.
+    *
+    * There are two implementations:
+    *
+    *    inside_fn: returns true if the point is inside
+    *    check_fn:  returns;
+    *       -1: the point is outside the shape by more than the filter width (2)
+    *        0: the point may be inside the shape
+    *       +1: the point is inside the shape by more than the filter width
+    */
+#define OUTSIDE (-1)
+#define INSIDE  (1)
+
+struct arg
+{
+   const struct color *color;
+   shape_fn_ptr        inside_fn;
+   shape_fn_ptr        check_fn;
+   double              width; /* line width, 0 for 'filled' */
+   double              x1, y1, x2, y2;
+};
+
+/* IMPLEMENTATION NOTE:
+ *
+ * We want the contribution of each shape to the sample corresponding to each
+ * pixel.  This could be obtained by super sampling the image to infinite
+ * dimensions, finding each point within the shape and assigning that a value
+ * '1' while leaving every point outside the shape with value '0' then
+ * downsampling to the image size with sinc; computationally very expensive.
+ *
+ * Approximations are as follows:
+ *
+ * 1) If the pixel coordinate is within the shape assume the sample has the
+ *    shape color and is opaque, else assume there is no contribution from
+ *    the shape.
+ *
+ *    This is the equivalent of aliased rendering or resampling an image with
+ *    a block filter.  The maximum error in the calculated alpha (which will
+ *    always be 0 or 1) is 0.5.
+ *
+ * 2) If the shape is within a square of size 1x1 centered on the pixel assume
+ *    that the shape obscures an amount of the pixel equal to its area within
+ *    that square.
+ *
+ *    This is the equivalent of 'pixel coverage' alpha calculation or resampling
+ *    an image with a bi-linear filter.  The maximum error is over 0.2, but the
+ *    results are often acceptable.
+ *
+ *    This can be approximated by applying (1) to a super-sampled image then
+ *    downsampling with a bi-linear filter.  The error in the super-sampled
+ *    image is 0.5 per sample, but the resampling reduces this.
+ *
+ * 3) Use a better filter with a super-sampled image; in the limit this is the
+ *    sinc() approach.
+ *
+ * 4) Do the geometric calculation; a bivariate definite integral across the
+ *    shape, unfortunately this means evaluating Si(x), the integral of sinc(x),
+ *    which is still a lot of math.
+ *
+ * This code uses approach (3) with a bi-cubic filter and 8x super-sampling
+ * and method (1) for the super-samples.  This means that the sample is either
+ * 0 or 1, depending on whether the sub-pixel is within or outside the shape.
+ * The bi-cubic weights are also fixed and the 16 required weights are
+ * pre-computed here (note that the 'scale' setting will need to be changed if
+ * 'super' is increased).
+ *
+ * The code also calculates a sum to the edge of the filter. This is not
+ * currently used by could be used to optimize the calculation.
+ */
+#if 0 /* bc code */
+scale=10
+super=8
+define bicubic(x) {
+   if (x <= 1) return (1.5*x - 2.5)*x*x + 1;
+   if (x <  2) return (((2.5 - 0.5*x)*x - 4)*x + 2);
+   return 0;
+}
+define sum(x) {
+   auto s;
+   s = 0;
+   while (x < 2*super) {
+      s = s + bicubic(x/super);
+      x = x + 1;
+   }
+   return s;
+}
+define results(x) {
+   auto b, s;
+   b = bicubic(x/super);
+   s = sum(x);
+
+   print "   /*", x, "*/ { ", b, ", ", s, " }";
+   return 1;
+}
+x=0
+while (x<2*super) {
+   x = x + results(x)
+   if (x < 2*super) print ","
+   print "\n"
+}
+quit
+#endif
+
+#define BICUBIC1(x) /*     |x| <= 1 */ ((1.5*(x)* - 2.5)*(x)*(x) + 1)
+#define BICUBIC2(x) /* 1 < |x| <  2 */ (((2.5 - 0.5*(x))*(x) - 4)*(x) + 2)
+#define FILTER_WEIGHT 9 /* Twice the first sum below */
+#define FILTER_WIDTH  2 /* Actually half the width; -2..+2 */
+#define FILTER_STEPS  8 /* steps per filter unit */
+static const double
+bicubic[16][2] =
+{
+   /* These numbers are exact; the weight for the filter is 1/9, but this
+    * would make the numbers inexact, so it is not included here.
+    */
+   /*          bicubic      sum        */
+   /* 0*/ { 1.0000000000, 4.5000000000 },
+   /* 1*/ {  .9638671875, 3.5000000000 },
+   /* 2*/ {  .8671875000, 2.5361328125 },
+   /* 3*/ {  .7275390625, 1.6689453125 },
+   /* 4*/ {  .5625000000,  .9414062500 },
+   /* 5*/ {  .3896484375,  .3789062500 },
+   /* 6*/ {  .2265625000, -.0107421875 },
+   /* 7*/ {  .0908203125, -.2373046875 },
+   /* 8*/ {            0, -.3281250000 },
+   /* 9*/ { -.0478515625, -.3281250000 },
+   /*10*/ { -.0703125000, -.2802734375 },
+   /*11*/ { -.0732421875, -.2099609375 },
+   /*12*/ { -.0625000000, -.1367187500 },
+   /*13*/ { -.0439453125, -.0742187500 },
+   /*14*/ { -.0234375000, -.0302734375 },
+   /*15*/ { -.0068359375, -.0068359375 }
+};
+
+static double
+alpha_calc(const struct arg *arg, double x, double y)
+{
+   /* For [x-2..x+2],[y-2,y+2] calculate the weighted bicubic given a function
+    * which tells us whether a point is inside or outside the shape.  First
+    * check if we need to do this at all:
+    */
+   switch (arg->check_fn(arg, x, y))
+   {
+      case OUTSIDE:
+         return 0; /* all samples outside the shape */
+
+      case INSIDE:
+         return 1; /* all samples inside the shape */
+
+      default:
+      {
+         int dy;
+         double alpha = 0;
+
+#        define FILTER_D (FILTER_WIDTH*FILTER_STEPS-1)
+         for (dy=-FILTER_D; dy<=FILTER_D; ++dy)
+         {
+            double wy = bicubic[abs(dy)][0];
+
+            if (wy != 0)
+            {
+               double alphay = 0;
+               int dx;
+
+               for (dx=-FILTER_D; dx<=FILTER_D; ++dx)
+               {
+                  double wx = bicubic[abs(dx)][0];
+
+                  if (wx != 0 && arg->inside_fn(arg, x+dx/16, y+dy/16)) 
+                     alphay += wx;
+               }
+
+               alpha += wy * alphay;
+            }
+         }
+
+         /* This needs to be weighted for each dimension: */
+         return alpha / (FILTER_WEIGHT*FILTER_WEIGHT);
+      }
+   }
+}
+
+/* These are the shape functions. */
+/* "square",
+ * { inside_square_filled, check_square_filled },
+ * { inside_square, check_square }
+ */
+static int
+square_check(double x, double y, double x1, double y1, double x2, double y2)
+   /* Is x,y inside the square (x1,y1)..(x2,y2)? */
+{
+   /* Do a modified Cohen-Sutherland on one point, bit patterns that indicate
+    * 'outside' are:
+    *
+    *   x<x1 | x<y1 | x<x2 | x<y2
+    *    0      x      0      x     To the right
+    *    1      x      1      x     To the left
+    *    x      0      x      0     Below
+    *    x      1      x      1     Above
+    *
+    * So 'inside' is (x<x1) != (x<x2) && (y<y1) != (y<y2);
+    */
+   return ((x<x1) ^ (x<x2)) & ((y<y1) ^ (y<y2));
+}
+
+static int
+inside_square_filled(const struct arg *arg, double x, double y)
+{
+   return square_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2);
+}
+
+static int
+square_check_line(const struct arg *arg, double x, double y, double w)
+   /* Check for a point being inside the boundaries implied by the given arg
+    * and assuming a width 2*w each side of the boundaries.  This returns the
+    * 'check' INSIDE/OUTSIDE/0 result but note the semantics:
+    *
+    *          +--------------+
+    *          |              |   OUTSIDE
+    *          |   INSIDE     |
+    *          |              |
+    *          +--------------+
+    *
+    * And '0' means within the line boundaries.
+    */
+{
+   double cx = (arg->x1+arg->x2)/2;
+   double wx = fabs(arg->x1-arg->x2)/2;
+   double cy = (arg->y1+arg->y2)/2;
+   double wy = fabs(arg->y1-arg->y2)/2;
+
+   if (square_check(x, y, cx-wx-w, cy-wy-w, cx+wx+w, cy+wy+w))
+   {
+      /* Inside, but maybe too far; check for the redundant case where
+       * the lines overlap:
+       */
+      wx -= w;
+      wy -= w;
+      if (wx > 0 && wy > 0 && square_check(x, y, cx-wx, cy-wy, cx+wx, cy+wy))
+         return INSIDE; /* between (inside) the boundary lines. */
+
+      return 0; /* inside the lines themselves. */
+   }
+
+   return OUTSIDE; /* outside the boundary lines. */
+}
+
+static int
+check_square_filled(const struct arg *arg, double x, double y)
+{
+   /* The filter extends +/-FILTER_WIDTH each side of each output point, so
+    * the check has to expand and contract the square by that amount; '0'
+    * means close enough to the edge of the square that the bicubic filter has
+    * to be run, OUTSIDE means alpha==0, INSIDE means alpha==1.
+    */
+   return square_check_line(arg, x, y, FILTER_WIDTH);
+}
+
+static int
+inside_square(const struct arg *arg, double x, double y)
+{
+   /* Return true if within the drawn lines, else false, no need to distinguish
+    * INSIDE vs OUTSIDE here:
+    */
+   return square_check_line(arg, x, y, arg->width/2) == 0;
+}
+
+static int
+check_square(const struct arg *arg, double x, double y)
+{
+   /* So for this function a result of 'INSIDE' means inside the actual lines.
+    */
+   double w = arg->width/2;
+
+   if (square_check_line(arg, x, y, w+FILTER_WIDTH) == 0)
+   {
+      /* Somewhere close to the boundary lines. If far enough inside one of
+       * them then we can return INSIDE:
+       */
+      w -= FILTER_WIDTH;
+
+      if (w > 0 && square_check_line(arg, x, y, w) == 0)
+         return INSIDE;
+
+      /* Point is somewhere in the filter region: */
+      return 0;
+   }
+
+   else /* Inside or outside the square by more than w+FILTER_WIDTH. */
+      return OUTSIDE;
+}
+
+/* "circle",
+ * { inside_circle_filled, check_circle_filled },
+ * { inside_circle, check_circle }
+ *
+ * The functions here are analoguous to the square ones; however, they check
+ * the corresponding ellipse as opposed to the rectangle.
+ */
+static int
+circle_check(double x, double y, double x1, double y1, double x2, double y2)
+{
+   if (square_check(x, y, x1, y1, x2, y2))
+   {
+      /* Inside the square, so maybe inside the circle too: */
+      const double cx = (x1 + x2)/2;
+      const double cy = (y1 + y2)/2;
+      const double dx = x1 - x2;
+      const double dy = y1 - y2;
+
+      x = (x - cx)/dx;
+      y = (y - cy)/dy;
+
+      /* It is outside if the distance from the center is more than half the
+       * diameter:
+       */
+      return x*x+y*y < .25;
+   }
+
+   return 0; /* outside */
+}
+
+static int
+inside_circle_filled(const struct arg *arg, double x, double y)
+{
+   return circle_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2);
+}
+
+static int
+circle_check_line(const struct arg *arg, double x, double y, double w)
+   /* Check for a point being inside the boundaries implied by the given arg
+    * and assuming a width 2*w each side of the boundaries.  This function has
+    * the same semantic as square_check_line but tests the circle.
+    */
+{
+   double cx = (arg->x1+arg->x2)/2;
+   double wx = fabs(arg->x1-arg->x2)/2;
+   double cy = (arg->y1+arg->y2)/2;
+   double wy = fabs(arg->y1-arg->y2)/2;
+
+   if (circle_check(x, y, cx-wx-w, cy-wy-w, cx+wx+w, cy+wy+w))
+   {
+      /* Inside, but maybe too far; check for the redundant case where
+       * the lines overlap:
+       */
+      wx -= w;
+      wy -= w;
+      if (wx > 0 && wy > 0 && circle_check(x, y, cx-wx, cy-wy, cx+wx, cy+wy))
+         return INSIDE; /* between (inside) the boundary lines. */
+
+      return 0; /* inside the lines themselves. */
+   }
+
+   return OUTSIDE; /* outside the boundary lines. */
+}
+
+static int
+check_circle_filled(const struct arg *arg, double x, double y)
+{
+   return circle_check_line(arg, x, y, FILTER_WIDTH);
+}
+
+static int
+inside_circle(const struct arg *arg, double x, double y)
+{
+   return circle_check_line(arg, x, y, arg->width/2) == 0;
+}
+
+static int
+check_circle(const struct arg *arg, double x, double y)
+{
+   /* Exactly as the 'square' code.  */
+   double w = arg->width/2;
+
+   if (circle_check_line(arg, x, y, w+FILTER_WIDTH) == 0)
+   {
+      w -= FILTER_WIDTH;
+
+      if (w > 0 && circle_check_line(arg, x, y, w) == 0)
+         return INSIDE;
+
+      /* Point is somewhere in the filter region: */
+      return 0;
+   }
+
+   else /* Inside or outside the square by more than w+FILTER_WIDTH. */
+      return OUTSIDE;
+}
+
+/* "line",
+ * { NULL, NULL },  There is no 'filled' line.
+ * { inside_line, check_line }
+ */
+static int
+line_check(double x, double y, double x1, double y1, double x2, double y2,
+   double w, double expand)
+{
+   /* Shift all the points to (arg->x1, arg->y1) */
+   double lx = x2 - x1;
+   double ly = y2 - y1;
+   double len2 = lx*lx + ly*ly;
+   double cross, dot;
+
+   x -= x1;
+   y -= y1;
+
+   /* The dot product is the distance down the line, the cross product is
+    * the distance away from the line:
+    *
+    *    distance = |cross| / sqrt(len2) 
+    */
+   cross = x * ly - y * lx;
+
+   /* If 'distance' is more than w the point is definitely outside the line:
+    *
+    *     distance >= w
+    *     |cross|  >= w * sqrt(len2)
+    *     cross^2  >= w^2 * len2:
+    */
+   if (cross*cross >= (w+expand)*(w+expand)*len2)
+      return 0; /* outside */
+
+   /* Now find the distance *along* the line; this comes from the dot product
+    * lx.x+ly.y. The actual distance (in pixels) is:
+    *
+    *   distance = dot / sqrt(len2)
+    */
+   dot = lx * x + ly * y;
+
+   /* The test for 'outside' is:
+    *
+    *    distance < 0 || distance > sqrt(len2)
+    *                 -> dot / sqrt(len2) > sqrt(len2)
+    *                 -> dot > len2
+    *
+    * But 'expand' is used for the filter width and needs to be handled too:
+    */
+   return dot > -expand && dot < len2+expand;
+}
+
+static int
+inside_line(const struct arg *arg, double x, double y)
+{
+   return line_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2, arg->width/2, 0);
+}
+
+static int
+check_line(const struct arg *arg, double x, double y)
+{
+   /* The end caps of the line must be checked too; it's not enough just to
+    * widen the line by FILTER_WIDTH; 'expand' exists for this purpose:
+    */
+   if (line_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2, arg->width/2,
+       FILTER_WIDTH))
+   {
+      /* Inside the line+filter; far enough inside that the filter isn't
+       * required?
+       */
+      if (arg->width > 2*FILTER_WIDTH &&
+          line_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2, arg->width/2,
+             -FILTER_WIDTH))
+         return INSIDE;
+
+      return 0;
+   }
+
+   return OUTSIDE;
+}
+
+static const struct
+{
+   const char    *name;
+   shape_fn_ptr   function[2/*fill,line*/][2];
+#  define         FN_INSIDE 0
+#  define         FN_CHECK 1
+} shape_defs[] =
+{
+   {  "square",
+      {  { inside_square_filled, check_square_filled },
+         { inside_square, check_square } }
+   },
+   {  "circle",
+      {  { inside_circle_filled, check_circle_filled },
+         { inside_circle, check_circle } }
+   },
+   {  "line",
+      {  { NULL, NULL },
+         { inside_line, check_line } }
+   }
+};
+
+#define shape_count ((sizeof shape_defs)/(sizeof shape_defs[0]))
+
+static shape_fn_ptr
+shape_of(const char *arg, double width, int f)
+{
+   unsigned int i;
+
+   for (i=0; i<shape_count; ++i) if (strcmp(shape_defs[i].name, arg) == 0)
+   {
+      shape_fn_ptr fn = shape_defs[i].function[width != 0][f];
+
+      if (fn != NULL)
+         return fn;
+
+      fprintf(stderr, "genpng: %s %s not supported\n",
+         width == 0 ? "filled" : "unfilled", arg);
+      exit(1);
+   }
+
+   fprintf(stderr, "genpng: %s: not a valid shape name\n", arg);
+   exit(1);
+}
+
+static void
+parse_arg(struct arg *arg, const char **argv/*7 arguments*/)
+{
+   /* shape ::= color width shape x1 y1 x2 y2 */
+   arg->color = color_of(argv[0]);
+   arg->width = width_of(argv[1]);
+   arg->inside_fn = shape_of(argv[2], arg->width, FN_INSIDE);
+   arg->check_fn = shape_of(argv[2], arg->width, FN_CHECK);
+   arg->x1 = coordinate_of(argv[3]);
+   arg->y1 = coordinate_of(argv[4]);
+   arg->x2 = coordinate_of(argv[5]);
+   arg->y2 = coordinate_of(argv[6]);
+}
+
+static png_uint_32
+read_wh(const char *name, const char *str)
+   /* read a PNG width or height */
+{
+   char *ep = NULL;
+   unsigned long ul = strtoul(str, &ep, 10);
+
+   if (ep != NULL && *ep == 0 && ul > 0 && ul <= 0x7fffffff)
+      return (png_uint_32)/*SAFE*/ul;
+
+   fprintf(stderr, "genpng: %s: invalid number %s\n", name, str);
+   exit(1);
+}
+
+static void
+pixel(png_uint_16p p, struct arg *args, int nargs, double x, double y)
+{
+   /* Fill in the pixel by checking each shape (args[nargs]) for effects on
+    * the corresponding sample:
+    */
+   double r=0, g=0, b=0, a=0;
+
+   while (--nargs >= 0 && a != 1)
+   {
+      /* NOTE: alpha_calc can return a value outside the range 0..1 with the
+       * bicubic filter.
+       */
+      const double alpha = alpha_calc(args+nargs, x, y) * (1-a);
+
+      r += alpha * args[nargs].color->red;
+      g += alpha * args[nargs].color->green;
+      b += alpha * args[nargs].color->blue;
+      a += alpha;
+   }
+
+   /* 'a' may be negative or greater than 1; if it is, negative clamp the
+    * pixel to 0 if >1 clamp r/g/b:
+    */
+   if (a > 0) 
+   {
+      if (a > 1)
+      {
+         if (r > 1) r = 1;
+         if (g > 1) g = 1;
+         if (b > 1) b = 1;
+         a = 1;
+      }
+
+      /* And fill in the pixel: */
+      p[0] = (png_uint_16)/*SAFE*/round(r * 65535);
+      p[1] = (png_uint_16)/*SAFE*/round(g * 65535);
+      p[2] = (png_uint_16)/*SAFE*/round(b * 65535);
+      p[3] = (png_uint_16)/*SAFE*/round(a * 65535);
+   }
+
+   else
+      p[3] = p[2] = p[1] = p[0] = 0;
+}
+
+int
+main(int argc, const char **argv)
+{
+   int convert_to_8bit = 0;
+
+   /* There is one option: --8bit: */
+   if (argc > 1 && strcmp(argv[1], "--8bit") == 0)
+      --argc, ++argv, convert_to_8bit = 1;
+
+   if (argc >= 3)
+   {
+      png_uint_16p buffer;
+      int nshapes;
+      png_image image;
+#     define max_shapes 256
+      struct arg arg_list[max_shapes];
+
+      /* The libpng Simplified API write code requires a fully initialized
+       * structure.
+       */
+      memset(&image, 0, sizeof image);
+      image.version = PNG_IMAGE_VERSION;
+      image.opaque = NULL;
+      image.width = read_wh("width", argv[1]);
+      image.height = read_wh("height", argv[2]);
+      image.format = PNG_FORMAT_LINEAR_RGB_ALPHA;
+      image.flags = 0;
+      image.colormap_entries = 0;
+
+      /* Check the remainder of the arguments */
+      for (nshapes=0; 3+7*(nshapes+1) <= argc && nshapes < max_shapes;
+           ++nshapes)
+         parse_arg(arg_list+nshapes, argv+3+7*nshapes);
+
+      if (3+7*nshapes != argc)
+      {
+         fprintf(stderr, "genpng: %s: too many arguments\n", argv[3+7*nshapes]);
+         return 1;
+      }
+
+      /* Create the buffer: */
+      buffer = malloc(PNG_IMAGE_SIZE(image));
+
+      if (buffer != NULL)
+      {
+         png_uint_32 y;
+
+         /* Write each row... */
+         for (y=0; y<image.height; ++y)
+         {
+            png_uint_32 x;
+
+            /* Each pixel in each row: */
+            for (x=0; x<image.width; ++x)
+               pixel(buffer + 4*(x + y*image.width), arg_list, nshapes, x, y);
+         }
+
+         /* Write the result (to stdout) */
+         if (png_image_write_to_stdio(&image, stdout, convert_to_8bit,
+             buffer, 0/*row_stride*/, NULL/*colormap*/))
+         {
+            free(buffer);
+            return 0; /* success */
+         }
+
+         else
+            fprintf(stderr, "genpng: write stdout: %s\n", image.message);
+
+         free(buffer);
+      }
+
+      else
+         fprintf(stderr, "genpng: out of memory: %lu bytes\n",
+               (unsigned long)PNG_IMAGE_SIZE(image));
+   }
+
+   else
+   {
+      /* Wrong number of arguments */
+      fprintf(stderr, "genpng: usage: genpng [--8bit] width height {shape}\n"
+         " Generate a transparent PNG in RGBA (truecolor+alpha) format\n"
+         " containing the given shape or shapes.  Shapes are defined:\n"
+         "\n"
+         "  shape ::= color width shape x1 y1 x2 y2\n"
+         "  color ::= black|white|red|green|yellow|blue\n"
+         "  color ::= brown|purple|pink|orange|gray|cyan\n"
+         "  width ::= filled|<number>\n"
+         "  shape ::= circle|square|line\n"
+         "  x1,x2 ::= <number>\n"
+         "  y1,y2 ::= <number>\n"
+         "\n"
+         " Numbers are floating point numbers describing points relative to\n"
+         " the top left of the output PNG as pixel coordinates.  The 'width'\n"
+         " parameter is either the width of the line (in output pixels) used\n"
+         " to draw the shape or 'filled' to indicate that the shape should\n"
+         " be filled with the color.\n"
+         "\n"
+         " Colors are interpreted loosely to give access to the eight full\n"
+         " intensity RGB values:\n"
+         "\n"
+         "  black, red, green, blue, yellow, cyan, purple, white,\n"
+         "\n"
+         " Cyan is full intensity blue+green; RGB(0,1,1), plus the following\n"
+         " lower intensity values:\n"
+         "\n"
+         "  brown:  red+orange:  RGB(0.5, 0.125, 0) (dark red+orange)\n"
+         "  pink:   red+white:   RGB(1.0, 0.5,   0.5)\n"
+         "  orange: red+yellow:  RGB(1.0, 0.5,   0)\n"
+         "  gray:   black+white: RGB(0.5, 0.5,   0.5)\n"
+         "\n"
+         " The RGB values are selected to make detection of aliasing errors\n"
+         " easy. The names are selected to make the description of errors\n"
+         " easy.\n"
+         "\n"
+         " The PNG is written to stdout, if --8bit is given a 32bpp RGBA sRGB\n"
+         " file is produced, otherwise a 64bpp RGBA linear encoded file is\n"
+         " written.\n");
+   }
+
+   return 1;
+}

contrib/tools/pngfix.c

@@ -1,15 +1,15 @@
 /* pngfix.c
  *
- * Copyright (c) 2014 John Cunningham Bowler
+ * Copyright (c) 2014-2015 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.17 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  *
- * Tool to check and fix the zlib inflate 'too far back' problem, see the usage
- * message for more information.
+ * Tool to check and fix the zlib inflate 'too far back' problem.
+ * See the usage message for more information.
  */
 #include <stdlib.h>
 #include <stdio.h>
@@ -49,6 +49,9 @@
 #  error "pngfix will not work with libpng prior to 1.6.3"
 #endif
 
+#ifdef PNG_SETJMP_SUPPORTED
+#include <setjmp.h>
+
 #if defined(PNG_READ_SUPPORTED) && defined(PNG_EASY_ACCESS_SUPPORTED)
 /* zlib.h defines the structure z_stream, an instance of which is included
  * in this structure and is required for decompressing the LZ compressed
@@ -68,8 +71,8 @@
  * with older builds.
  */
 #if ZLIB_VERNUM < 0x1260
-#  define PNGZ_MSG_CAST(s) png_constcast(char*,s)
-#  define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
+#  define PNGZ_MSG_CAST(s) constcast(char*,s)
+#  define PNGZ_INPUT_CAST(b) constcast(png_bytep,b)
 #else
 #  define PNGZ_MSG_CAST(s) (s)
 #  define PNGZ_INPUT_CAST(b) (b)
@@ -83,17 +86,17 @@
 
 /* Copied from pngpriv.h */
 #ifdef __cplusplus
-#  define png_voidcast(type, value) static_cast<type>(value)
-#  define png_constcast(type, value) const_cast<type>(value)
-#  define png_aligncast(type, value) \
+#  define voidcast(type, value) static_cast<type>(value)
+#  define constcast(type, value) const_cast<type>(value)
+#  define aligncast(type, value) \
    static_cast<type>(static_cast<void*>(value))
-#  define png_aligncastconst(type, value) \
+#  define aligncastconst(type, value) \
    static_cast<type>(static_cast<const void*>(value))
 #else
-#  define png_voidcast(type, value) (value)
-#  define png_constcast(type, value) ((type)(value))
-#  define png_aligncast(type, value) ((void*)(value))
-#  define png_aligncastconst(type, value) ((const void*)(value))
+#  define voidcast(type, value) (value)
+#  define constcast(type, value) ((type)(value))
+#  define aligncast(type, value) ((void*)(value))
+#  define aligncastconst(type, value) ((const void*)(value))
 #endif /* __cplusplus */
 
 #if PNG_LIBPNG_VER < 10700
@@ -443,7 +446,7 @@ static void
 make_random_bytes(png_uint_32* seed, void* pv, size_t size)
 {
    png_uint_32 u0 = seed[0], u1 = seed[1];
-   png_bytep bytes = png_voidcast(png_bytep, pv);
+   png_bytep bytes = voidcast(png_bytep, pv);
 
    /* There are thirty-three bits; the next bit in the sequence is bit-33 XOR
     * bit-20.  The top 1 bit is in u1, the bottom 32 are in u0.
@@ -665,7 +668,7 @@ IDAT_list_extend(struct IDAT_list *tail)
       if (length < tail->length) /* arithmetic overflow */
          length = tail->length;
             
-      next = png_voidcast(IDAT_list*, malloc(IDAT_list_size(NULL, length)));
+      next = voidcast(IDAT_list*, malloc(IDAT_list_size(NULL, length)));
       CLEAR(*next);
 
       /* The caller must handle this: */
@@ -2135,7 +2138,7 @@ zlib_end(struct zlib *zlib)
           *
           * z-rc is the zlib failure code; message is the error message with
           * spaces replaced by '-'.  The compressed byte count indicates where
-          * in the zlib stream the error occured.
+          * in the zlib stream the error occurred.
           */
          type_name(zlib->chunk->chunk_type, stdout);
          printf(" SKP %s %d %s ", zlib_flevel(zlib), zlib->file_bits,
@@ -3532,7 +3535,7 @@ get_control(png_const_structrp png_ptr)
    /* This just returns the (file*).  The chunk and idat control structures
     * don't always exist.
     */
-   struct control *control = png_voidcast(struct control*,
+   struct control *control = voidcast(struct control*,
       png_get_error_ptr(png_ptr));
    return &control->file;
 }
@@ -3540,7 +3543,7 @@ get_control(png_const_structrp png_ptr)
 static void
 allocate(struct file *file, int allocate_idat)
 {
-   struct control *control = png_voidcast(struct control*, file->alloc_ptr);
+   struct control *control = voidcast(struct control*, file->alloc_ptr);
 
    if (allocate_idat)
    {
@@ -3574,7 +3577,6 @@ read_png(struct control *control)
 {
    png_structp png_ptr;
    png_infop info_ptr = NULL;
-   volatile png_bytep row = NULL, display = NULL;
    volatile int rc;
 
    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, control,
@@ -3591,6 +3593,16 @@ read_png(struct control *control)
    rc = setjmp(control->file.jmpbuf);
    if (rc == 0)
    {
+#     ifdef PNG_SET_USER_LIMITS_SUPPORTED
+         /* Remove any limits on the size of PNG files that can be read,
+          * without this we may reject files based on built-in safety
+          * limits.
+          */
+         png_set_user_limits(png_ptr, 0x7fffffff, 0x7fffffff);
+         png_set_chunk_cache_max(png_ptr, 0);
+         png_set_chunk_malloc_max(png_ptr, 0);
+#     endif
+
       png_set_read_fn(png_ptr, control, read_callback);
 
       info_ptr = png_create_info_struct(png_ptr);
@@ -3603,32 +3615,22 @@ read_png(struct control *control)
       png_read_info(png_ptr, info_ptr);
 
       {
-         png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+        png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
+        int passes = png_set_interlace_handling(png_ptr);
+        int pass;
 
-         row = png_voidcast(png_byte*, malloc(rowbytes));
-         display = png_voidcast(png_byte*, malloc(rowbytes));
+        png_start_read_image(png_ptr);
 
-         if (row == NULL || display == NULL)
-            png_error(png_ptr, "OOM allocating row buffers");
+        for (pass = 0; pass < passes; ++pass)
+        {
+           png_uint_32 y = height;
 
-         {
-            png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
-            int passes = png_set_interlace_handling(png_ptr);
-            int pass;
-
-            png_start_read_image(png_ptr);
-
-            for (pass = 0; pass < passes; ++pass)
-            {
-               png_uint_32 y = height;
-
-               /* NOTE: this trashes the row each time; interlace handling won't
-                * work, but this avoids memory thrashing for speed testing.
-                */
-               while (y-- > 0)
-                  png_read_row(png_ptr, row, display);
-            }
-         }
+           /* NOTE: this skips asking libpng to return either version of
+            * the image row, but libpng still reads the rows.
+            */
+           while (y-- > 0)
+              png_read_row(png_ptr, NULL, NULL);
+        }
       }
 
       if (control->file.global->verbose)
@@ -3639,8 +3641,6 @@ read_png(struct control *control)
    }
 
    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-   if (row != NULL) free(row);
-   if (display != NULL) free(display);
    return rc;
 }
 
@@ -3702,21 +3702,21 @@ usage(const char *prog)
 "        gAMA, sRGB [all]: These specify the gamma encoding used for the pixel",
 "            values.",
 "        cHRM, iCCP [color]: These specify how colors are encoded.  iCCP also",
-"            specifies the exact encoding of a pixel value however in practice",
-"            most programs will ignore it.",
+"            specifies the exact encoding of a pixel value; however, in",
+"            practice most programs will ignore it.",
 "        bKGD [transform]: This is used by libpng transforms."
 "    --max=<number>:",
 "      Use IDAT chunks sized <number>.  If no number is given the the IDAT",
 "      chunks will be the maximum size permitted; 2^31-1 bytes.  If the option",
 "      is omitted the original chunk sizes will not be changed.  When the",
-"      option is given --strip=unsafe is set automatically, this may be",
+"      option is given --strip=unsafe is set automatically. This may be",
 "      cancelled if you know that all unknown unsafe-to-copy chunks really are",
 "      safe to copy across an IDAT size change.  This is true of all chunks",
 "      that have ever been formally proposed as PNG extensions.",
 "  MESSAGES",
 "      By default the program only outputs summaries for each file.",
 "    --quiet (-q):",
-"      Do not output the summaries except for files which cannot be read. With",
+"      Do not output the summaries except for files that cannot be read. With",
 "      two --quiets these are not output either.",
 "    --errors (-e):",
 "      Output errors from libpng and the program (except too-far-back).",
@@ -3749,7 +3749,7 @@ usage(const char *prog)
 "  the following codes.  Notice that the results for each file are combined",
 "  together - check one file at a time to get a meaningful error code!",
 "    0x01: The zlib too-far-back error existed in at least one chunk.",
-"    0x02: At least once chunk had a CRC error.",
+"    0x02: At least one chunk had a CRC error.",
 "    0x04: A chunk length was incorrect.",
 "    0x08: The file was truncated.",
 "  Errors less than 16 are potentially recoverable, for a single file if the",
@@ -3757,7 +3757,7 @@ usage(const char *prog)
 "  non-zero code is returned).",
 "    0x10: The file could not be read, even with corrections.",
 "    0x20: The output file could not be written.",
-"    0x40: An unexpected, potentially internal, error occured.",
+"    0x40: An unexpected, potentially internal, error occurred.",
 "  If the command line arguments are incorrect the program exits with exit",
 "  255.  Some older operating systems only support 7-bit exit codes, on those",
 "  systems it is suggested that this program is first tested by supplying",
@@ -3817,7 +3817,7 @@ usage(const char *prog)
 "          SKP: The chunk was skipped because of a zlib issue (zlib-rc) with",
 "               explanation 'message'",
 "          ERR: The read of the file was aborted.  The parameters explain why.",
-"$3 status:     For 'ERR' the accumulate status code from 'EXIT CODES' above.",
+"$3 status:     For 'ERR' the accumulated status code from 'EXIT CODES' above.",
 "               This is printed as a 2 digit hexadecimal value",
 "   comp-level: The recorded compression level (FLEVEL) of a zlib stream",
 "               expressed as a string {supfast,stdfast,default,maximum}",
@@ -4034,3 +4034,12 @@ main(void)
    return 77;
 }
 #endif /* PNG_READ_SUPPORTED && PNG_EASY_ACCESS_SUPPORTED */
+#else /* No setjmp support */
+int
+main(void)
+{
+   fprintf(stderr, "pngfix does not work without setjmp support\n");
+   return 77;
+}
+#endif /* PNG_SETJMP_SUPPORTED */
+

contrib/visupng/PngFile.c

@@ -136,7 +136,7 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
 
     /* create the two png(-info) structures */
 
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL,
+    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), NULL,
       (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
     if (!png_ptr)
     {
@@ -313,7 +313,7 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
 
     /* prepare the standard PNG structures */
 
-    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
+    png_ptr = png_create_write_struct(png_get_libpng_ver(NULL), NULL,
       (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
     if (!png_ptr)
     {

example.c

@@ -2,7 +2,7 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.6.11 [June 5, 2014]
+ * Last changed in libpng 1.6.15 [November 20, 2014]
  * Maintained 1998-2014 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
  * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -52,7 +52,7 @@ int main(int argc, const char **argv)
       image.version = PNG_IMAGE_VERSION;
 
       /* The first argument is the file to read: */
-      if (png_image_begin_read_from_file(&image, argv[1]))
+      if (png_image_begin_read_from_file(&image, argv[1]) != 0)
       {
          png_bytep buffer;
 
@@ -97,7 +97,7 @@ int main(int argc, const char **argv)
           */
          if (buffer != NULL &&
             png_image_finish_read(&image, NULL/*background*/, buffer,
-               0/*row_stride*/, NULL/*colormap*/))
+               0/*row_stride*/, NULL/*colormap*/) != 0)
          {
             /* Now write the image out to the second argument.  In the write
              * call 'convert_to_8bit' allows 16-bit data to be squashed down to
@@ -105,7 +105,7 @@ int main(int argc, const char **argv)
              * to the 8-bit format.
              */
             if (png_image_write_to_file(&image, argv[2], 0/*convert_to_8bit*/,
-               buffer, 0/*row_stride*/, NULL/*colormap*/))
+               buffer, 0/*row_stride*/, NULL/*colormap*/) != 0)
             {
                /* The image has been written successfully. */
                exit(0);
@@ -188,13 +188,13 @@ int main(int argc, const char **argv)
  *
  * Don't repeatedly convert between the 8-bit and 16-bit forms.  There is
  * significant data loss when 16-bit data is converted to the 8-bit encoding and
- * the current libpng implementation of convertion to 16-bit is also
+ * the current libpng implementation of conversion to 16-bit is also
  * significantly lossy.  The latter will be fixed in the future, but the former
  * is unavoidable - the 8-bit format just doesn't have enough resolution.
  */
 
 /* If your program needs more information from the PNG data it reads, or if you
- * need to do more complex transformations, or minimise transformations, on the
+ * need to do more complex transformations, or minimize transformations, on the
  * data you read, then you must use one of the several lower level libpng
  * interfaces.
  *
@@ -405,7 +405,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    /* Expand paletted or RGB images with transparency to full alpha channels
     * so the data will be available as RGBA quartets.
     */
-   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) != 0)
       png_set_tRNS_to_alpha(png_ptr);
 
    /* Set the background color to draw transparent and alpha images over.
@@ -417,7 +417,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
 
    png_color_16 my_background, *image_background;
 
-   if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+   if (png_get_bKGD(png_ptr, info_ptr, &image_background) != 0)
       png_set_background(png_ptr, image_background,
                          PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
    else
@@ -454,12 +454,12 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
 
    int intent;
 
-   if (png_get_sRGB(png_ptr, info_ptr, &intent))
+   if (png_get_sRGB(png_ptr, info_ptr, &intent) != 0)
       png_set_gamma(png_ptr, screen_gamma, PNG_DEFAULT_sRGB);
    else
    {
       double image_gamma;
-      if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
+      if (png_get_gAMA(png_ptr, info_ptr, &image_gamma) != 0)
          png_set_gamma(png_ptr, screen_gamma, image_gamma);
       else
          png_set_gamma(png_ptr, screen_gamma, 0.45455);
@@ -469,7 +469,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    /* Quantize RGB files down to 8 bit palette or reduce palettes
     * to the number of colors available on your screen.
     */
-   if (color_type & PNG_COLOR_MASK_COLOR)
+   if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       int num_palette;
       png_colorp palette;
@@ -484,7 +484,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
             MAX_SCREEN_COLORS, NULL, 0);
       }
       /* This reduces the image to the palette supplied in the file */
-      else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette))
+      else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) != 0)
       {
          png_uint_16p histogram = NULL;
 
@@ -494,7 +494,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
                         max_screen_colors, histogram, 0);
       }
    }
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#endif /* READ_QUANTIZE */
 
    /* Invert monochrome files to have 0 as white and 1 as black */
    png_set_invert_mono(png_ptr);
@@ -503,7 +503,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
     * [0,65535] to the original [0,7] or [0,31], or whatever range the
     * colors were originally in:
     */
-   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT) != 0)
    {
       png_color_8p sig_bit_p;
 
@@ -512,7 +512,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    }
 
    /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
-   if (color_type & PNG_COLOR_MASK_COLOR)
+   if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
       png_set_bgr(png_ptr);
 
    /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
@@ -532,7 +532,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    number_passes = png_set_interlace_handling(png_ptr);
 #else
    number_passes = 1;
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
+#endif /* READ_INTERLACING */
 
 
    /* Optional call to gamma correct and add the background to the palette
@@ -744,7 +744,7 @@ row_callback(png_structp png_ptr, png_bytep new_row,
     * to pass the current row as new_row, and the function will combine
     * the old row and the new row.
     */
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
+#endif /* READ_INTERLACING */
 }
 
 end_callback(png_structp png_ptr, png_infop info)
@@ -932,7 +932,7 @@ void write_png(char *file_name /* , ... other image information ... */)
     */
 
    /* Once we write out the header, the compression type on the text
-    * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
+    * chunk gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
     * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
     * at the end.
     */

libpng-manual.txt

@@ -1,9 +1,9 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.13 - August 21, 2014
+ libpng version 1.6.18beta05 - May 31, 2015
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
  For conditions of distribution and use, see the disclaimer
@@ -11,9 +11,9 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.13 - August 21, 2014
+ libpng versions 0.97, January 1998, through 1.6.18beta05 - May 31, 2015
  Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6 - version 0.96 - May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -336,7 +336,7 @@ prediction.
 
 If you are intending to keep the file pointer open for use in libpng,
 you must ensure you don't read more than 8 bytes from the beginning
-of the file, and you also have to make a call to png_set_sig_bytes_read()
+of the file, and you also have to make a call to png_set_sig_bytes()
 with the number of bytes you read from the beginning.  Libpng will
 then only check the bytes (if any) that your program didn't read.
 
@@ -344,22 +344,23 @@ then only check the bytes (if any) that your program didn't read.
 to replace them with custom functions.  See the discussion under
 Customizing libpng.
 
-
     FILE *fp = fopen(file_name, "rb");
     if (!fp)
     {
        return (ERROR);
     }
 
-    fread(header, 1, number, fp);
-    is_png = !png_sig_cmp(header, 0, number);
+    if (fread(header, 1, number, fp) != number)
+    {
+       return (ERROR);
+    }
 
+    is_png = !png_sig_cmp(header, 0, number);
     if (!is_png)
     {
        return (NOT_PNG);
     }
 
-
 Next, png_struct and png_info need to be allocated and initialized.  In
 order to ensure that the size of these structures is correct even with a
 dynamically linked libpng, there are functions to initialize and
@@ -648,15 +649,12 @@ User limits
 
 The PNG specification allows the width and height of an image to be as
 large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
-Since very few applications really need to process such large images,
-we have imposed an arbitrary 1-million limit on rows and columns.
 Larger images will be rejected immediately with a png_error() call. If
-you wish to change this limit, you can use
+you wish to change these limits, you can use
 
    png_set_user_limits(png_ptr, width_max, height_max);
 
-to set your own limits, or use width_max = height_max = 0x7fffffffL
-to allow all valid dimensions (libpng may reject some very large images
+to set your own limits (libpng may reject some very wide images
 anyway because of potential buffer overflow conditions).
 
 You should put this statement after you create the PNG structure and
@@ -1267,13 +1265,13 @@ in until png_read_end() has read the chunk data following the image.
                      the PNG datastream is embedded in
                      a MNG-1.0 datastream)
 
-    Any or all of interlace_type, compression_type, or
-    filter_method can be NULL if you are
-    not interested in their values.
+    Any of width, height, color_type, bit_depth,
+    interlace_type, compression_type, or filter_method can
+    be NULL if you are not interested in their values.
 
     Note that png_get_IHDR() returns 32-bit data into
     the application's width and height variables.
-    This is an unsafe situation if these are 16-bit
+    This is an unsafe situation if these are not png_uint_32
     variables.  In such situations, the
     png_get_image_width() and png_get_image_height()
     functions described below are safer.
@@ -1996,7 +1994,7 @@ value when you call it in this position:
       png_set_gamma(png_ptr, screen_gamma, 0.45455);
 
 If you need to reduce an RGB file to a paletted file, or if a paletted
-file has more entries then will fit on your screen, png_set_quantize()
+file has more entries than will fit on your screen, png_set_quantize()
 will do that.  Note that this is a simple match quantization that merely
 finds the closest color available.  This should work fairly well with
 optimized palettes, but fairly badly with linear color cubes.  If you
@@ -2549,7 +2547,7 @@ png_infop info_ptr;
        64K.  The library seems to run fine with sizes
        of 4K. Although you can give it much less if
        necessary (I assume you can give it chunks of
-       1 byte, I haven't tried less then 256 bytes
+       1 byte, I haven't tried less than 256 bytes
        yet).  When this function returns, you may
        want to display any rows that were generated
        in the row callback if you don't already do
@@ -3261,7 +3259,7 @@ tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
 although this isn't a requirement.  Unlike the tIME chunk, the
 "Creation Time" tEXt chunk is not expected to be automatically changed
 by the software.  To facilitate the use of RFC 1123 dates, a function
-png_convert_to_rfc1123_buffer(png_ptr, buffer, png_timep) is provided to
+png_convert_to_rfc1123_buffer(buffer, png_timep) is provided to
 convert from PNG time to an RFC 1123 format string.  The caller must provide
 a writeable buffer of at least 29 bytes.
 
@@ -4067,10 +4065,11 @@ a 16-bit linear encoded PNG file is written.
 
 With all APIs row_stride is handled as in the read APIs - it is the spacing
 from one row to the next in component sized units (float) and if negative
-indicates a bottom-up row layout in the buffer.
+indicates a bottom-up row layout in the buffer.  If you pass zero, libpng will
+calculate the row_stride for you from the width and number of channels.
 
 Note that the write API does not support interlacing, sub-8-bit pixels,
-and indexed (paletted) images.
+indexed (paletted) images, or most ancillary chunks.
 
 VI. Modifying/Customizing libpng
 
@@ -5034,11 +5033,15 @@ The signatures of many exported functions were changed, such that
    png_infop became png_inforp or png_const_inforp
 where "rp" indicates a "restricted pointer".
 
+The support for FAR/far types has been eliminated and the definition of
+png_alloc_size_t is now controlled by a flag so that 'small size_t' systems
+can select it if necessary.
+
 Error detection in some chunks has improved; in particular the iCCP chunk
 reader now does pretty complete validation of the basic format.  Some bad
 profiles that were previously accepted are now accepted with a warning or
-rejected, depending upon the png_set_benign_errors() setting, in particular the
-very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
+rejected, depending upon the png_set_benign_errors() setting, in particular
+the very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
 libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
 means of
 
@@ -5049,7 +5052,7 @@ means of
     #endif
 
 It's not a good idea to do this if you are using the "simplified API",
-which needs to be able to recognize an sRGB profile conveyed via the iCCP
+which needs to be able to recognize sRGB profiles conveyed via the iCCP
 chunk.
 
 The PNG spec requirement that only grayscale profiles may appear in images
@@ -5107,6 +5110,23 @@ length, which resulted in PNG files that cannot be read beyond the bad iTXt
 chunk.  This error was fixed in libpng-1.6.3, and a tool (called
 contrib/tools/png-fix-itxt) has been added to the libpng distribution.
 
+Starting with libpng-1.6.17, the PNG_SAFE_LIMITS macro was eliminated
+and safe limits are used by default (users who need larger limits
+can still override them at compile time or run time, as described above).
+
+The new limits are
+                                default   spec limit
+   png_user_width_max         1,000,000  2,147,483,647
+   png_user_height_max        1,000,000  2,147,483,647
+   png_user_chunk_cache_max         128  unlimited
+   png_user_chunk_malloc_max  8,000,000  unlimited
+
+Starting with libpng-1.6.18, a PNG_RELEASE_BUILD macro was added, which allows
+library builders to control compilation for an installed system (a release build).
+It can be set for testing debug or beta builds to ensure that they will compile
+when the build type is switched to RC or STABLE. In essence this overrides the
+PNG_LIBPNG_BUILD_BASE_TYPE definition which is not directly user controllable.
+
 XIII.  Detecting libpng
 
 The png_get_io_ptr() function has been present since libpng-0.88, has never
@@ -5223,12 +5243,15 @@ We mark all non-exported functions with "/* PRIVATE */"":
  }
 
 The prototypes for non-exported functions (except for those in
-pngtest) appear in
-pngpriv.h
-above the comment that says
+pngtest) appear in pngpriv.h above the comment that says
 
   /* Maintainer: Put new private prototypes here ^ */
 
+To avoid polluting the global namespace, the names of all exported
+functions and variables begin with "png_", and all publicly visible C
+preprocessor macros begin with "PNG".  We request that applications that
+use libpng *not* begin any of their own symbols with either of these strings.
+
 We put a space after the "sizeof" operator and we omit the
 optional parentheses around its argument when the argument
 is an expression, not a type name, and we always enclose the
@@ -5240,10 +5263,8 @@ sizeof operator, with its argument, in parentheses:
 Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
 though it were a function.
 
-To avoid polluting the global namespace, the names of all exported
-functions and variables begin with "png_", and all publicly visible C
-preprocessor macros begin with "PNG".  We request that applications that
-use libpng *not* begin any of their own symbols with either of these strings.
+Control keywords if, for, while, and switch are always followed by a space
+to distinguish them from function calls, which have no trailing space. 
 
 We put a space after each comma and after each semicolon
 in "for" statements, and we put spaces before and after each
@@ -5276,13 +5297,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 XVI. Y2K Compliance in libpng
 
-August 21, 2014
+May 31, 2015
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.13 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.18beta05 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
@@ -5298,8 +5319,9 @@ in libpng-1.6.x and will be removed from libpng-1.7.0.
 
 There are seven time-related functions:
 
-    png_convert_to_rfc_1123() in png.c
-      (formerly png_convert_to_rfc_1152() in error)
+    png_convert_to_rfc_1123_buffer() in png.c
+      (formerly png_convert_to_rfc_1152() in error, and
+      also formerly png_convert_to_rfc_1123())
     png_convert_from_struct_tm() in pngwrite.c, called
       in pngwrite.c
     png_convert_from_time_t() in pngwrite.c

libpng.3

@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "August 21, 2014"
+.TH LIBPNG 3 "May 31, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.13
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.18beta05
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -504,10 +504,10 @@ 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 1.6.13 - August 21, 2014
+ libpng version 1.6.18beta05 - May 31, 2015
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
  For conditions of distribution and use, see the disclaimer
@@ -515,9 +515,9 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.13 - August 21, 2014
+ libpng versions 0.97, January 1998, through 1.6.18beta05 - May 31, 2015
  Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6 - version 0.96 - May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -840,7 +840,7 @@ prediction.
 
 If you are intending to keep the file pointer open for use in libpng,
 you must ensure you don't read more than 8 bytes from the beginning
-of the file, and you also have to make a call to png_set_sig_bytes_read()
+of the file, and you also have to make a call to png_set_sig_bytes()
 with the number of bytes you read from the beginning.  Libpng will
 then only check the bytes (if any) that your program didn't read.
 
@@ -848,22 +848,23 @@ then only check the bytes (if any) that your program didn't read.
 to replace them with custom functions.  See the discussion under
 Customizing libpng.
 
-
     FILE *fp = fopen(file_name, "rb");
     if (!fp)
     {
        return (ERROR);
     }
 
-    fread(header, 1, number, fp);
-    is_png = !png_sig_cmp(header, 0, number);
+    if (fread(header, 1, number, fp) != number)
+    {
+       return (ERROR);
+    }
 
+    is_png = !png_sig_cmp(header, 0, number);
     if (!is_png)
     {
        return (NOT_PNG);
     }
 
-
 Next, png_struct and png_info need to be allocated and initialized.  In
 order to ensure that the size of these structures is correct even with a
 dynamically linked libpng, there are functions to initialize and
@@ -1152,15 +1153,12 @@ callback function:
 
 The PNG specification allows the width and height of an image to be as
 large as 2^(31\-1 (0x7fffffff), or about 2.147 billion rows and columns.
-Since very few applications really need to process such large images,
-we have imposed an arbitrary 1-million limit on rows and columns.
 Larger images will be rejected immediately with a png_error() call. If
-you wish to change this limit, you can use
+you wish to change these limits, you can use
 
    png_set_user_limits(png_ptr, width_max, height_max);
 
-to set your own limits, or use width_max = height_max = 0x7fffffffL
-to allow all valid dimensions (libpng may reject some very large images
+to set your own limits (libpng may reject some very wide images
 anyway because of potential buffer overflow conditions).
 
 You should put this statement after you create the PNG structure and
@@ -1771,13 +1769,13 @@ in until png_read_end() has read the chunk data following the image.
                      the PNG datastream is embedded in
                      a MNG-1.0 datastream)
 
-    Any or all of interlace_type, compression_type, or
-    filter_method can be NULL if you are
-    not interested in their values.
+    Any of width, height, color_type, bit_depth,
+    interlace_type, compression_type, or filter_method can
+    be NULL if you are not interested in their values.
 
     Note that png_get_IHDR() returns 32-bit data into
     the application's width and height variables.
-    This is an unsafe situation if these are 16-bit
+    This is an unsafe situation if these are not png_uint_32
     variables.  In such situations, the
     png_get_image_width() and png_get_image_height()
     functions described below are safer.
@@ -2500,7 +2498,7 @@ value when you call it in this position:
       png_set_gamma(png_ptr, screen_gamma, 0.45455);
 
 If you need to reduce an RGB file to a paletted file, or if a paletted
-file has more entries then will fit on your screen, png_set_quantize()
+file has more entries than will fit on your screen, png_set_quantize()
 will do that.  Note that this is a simple match quantization that merely
 finds the closest color available.  This should work fairly well with
 optimized palettes, but fairly badly with linear color cubes.  If you
@@ -3053,7 +3051,7 @@ png_infop info_ptr;
        64K.  The library seems to run fine with sizes
        of 4K. Although you can give it much less if
        necessary (I assume you can give it chunks of
-       1 byte, I haven't tried less then 256 bytes
+       1 byte, I haven't tried less than 256 bytes
        yet).  When this function returns, you may
        want to display any rows that were generated
        in the row callback if you don't already do
@@ -3765,7 +3763,7 @@ tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
 although this isn't a requirement.  Unlike the tIME chunk, the
 "Creation Time" tEXt chunk is not expected to be automatically changed
 by the software.  To facilitate the use of RFC 1123 dates, a function
-png_convert_to_rfc1123_buffer(png_ptr, buffer, png_timep) is provided to
+png_convert_to_rfc1123_buffer(buffer, png_timep) is provided to
 convert from PNG time to an RFC 1123 format string.  The caller must provide
 a writeable buffer of at least 29 bytes.
 
@@ -4571,10 +4569,11 @@ a 16-bit linear encoded PNG file is written.
 
 With all APIs row_stride is handled as in the read APIs - it is the spacing
 from one row to the next in component sized units (float) and if negative
-indicates a bottom-up row layout in the buffer.
+indicates a bottom-up row layout in the buffer.  If you pass zero, libpng will
+calculate the row_stride for you from the width and number of channels.
 
 Note that the write API does not support interlacing, sub-8-bit pixels,
-and indexed (paletted) images.
+indexed (paletted) images, or most ancillary chunks.
 
 .SH VI. Modifying/Customizing libpng
 
@@ -5538,11 +5537,15 @@ The signatures of many exported functions were changed, such that
    png_infop became png_inforp or png_const_inforp
 where "rp" indicates a "restricted pointer".
 
+The support for FAR/far types has been eliminated and the definition of
+png_alloc_size_t is now controlled by a flag so that 'small size_t' systems
+can select it if necessary.
+
 Error detection in some chunks has improved; in particular the iCCP chunk
 reader now does pretty complete validation of the basic format.  Some bad
 profiles that were previously accepted are now accepted with a warning or
-rejected, depending upon the png_set_benign_errors() setting, in particular the
-very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
+rejected, depending upon the png_set_benign_errors() setting, in particular
+the very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
 libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
 means of
 
@@ -5553,7 +5556,7 @@ means of
     #endif
 
 It's not a good idea to do this if you are using the "simplified API",
-which needs to be able to recognize an sRGB profile conveyed via the iCCP
+which needs to be able to recognize sRGB profiles conveyed via the iCCP
 chunk.
 
 The PNG spec requirement that only grayscale profiles may appear in images
@@ -5611,6 +5614,23 @@ length, which resulted in PNG files that cannot be read beyond the bad iTXt
 chunk.  This error was fixed in libpng-1.6.3, and a tool (called
 contrib/tools/png-fix-itxt) has been added to the libpng distribution.
 
+Starting with libpng-1.6.17, the PNG_SAFE_LIMITS macro was eliminated
+and safe limits are used by default (users who need larger limits
+can still override them at compile time or run time, as described above).
+
+The new limits are
+                                default   spec limit
+   png_user_width_max         1,000,000  2,147,483,647
+   png_user_height_max        1,000,000  2,147,483,647
+   png_user_chunk_cache_max         128  unlimited
+   png_user_chunk_malloc_max  8,000,000  unlimited
+
+Starting with libpng-1.6.18, a PNG_RELEASE_BUILD macro was added, which allows
+library builders to control compilation for an installed system (a release build).
+It can be set for testing debug or beta builds to ensure that they will compile
+when the build type is switched to RC or STABLE. In essence this overrides the
+PNG_LIBPNG_BUILD_BASE_TYPE definition which is not directly user controllable.
+
 .SH XIII.  Detecting libpng
 
 The png_get_io_ptr() function has been present since libpng-0.88, has never
@@ -5727,12 +5747,15 @@ We mark all non-exported functions with "/* PRIVATE */"":
  }
 
 The prototypes for non-exported functions (except for those in
-pngtest) appear in
-pngpriv.h
-above the comment that says
+pngtest) appear in pngpriv.h above the comment that says
 
   /* Maintainer: Put new private prototypes here ^ */
 
+To avoid polluting the global namespace, the names of all exported
+functions and variables begin with "png_", and all publicly visible C
+preprocessor macros begin with "PNG".  We request that applications that
+use libpng *not* begin any of their own symbols with either of these strings.
+
 We put a space after the "sizeof" operator and we omit the
 optional parentheses around its argument when the argument
 is an expression, not a type name, and we always enclose the
@@ -5744,10 +5767,8 @@ sizeof operator, with its argument, in parentheses:
 Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
 though it were a function.
 
-To avoid polluting the global namespace, the names of all exported
-functions and variables begin with "png_", and all publicly visible C
-preprocessor macros begin with "PNG".  We request that applications that
-use libpng *not* begin any of their own symbols with either of these strings.
+Control keywords if, for, while, and switch are always followed by a space
+to distinguish them from function calls, which have no trailing space. 
 
 We put a space after each comma and after each semicolon
 in "for" statements, and we put spaces before and after each
@@ -5780,13 +5801,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 .SH XVI. Y2K Compliance in libpng
 
-August 21, 2014
+May 31, 2015
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.13 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.18beta05 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
@@ -5802,8 +5823,9 @@ in libpng-1.6.x and will be removed from libpng-1.7.0.
 
 There are seven time-related functions:
 
-    png_convert_to_rfc_1123() in png.c
-      (formerly png_convert_to_rfc_1152() in error)
+    png_convert_to_rfc_1123_buffer() in png.c
+      (formerly png_convert_to_rfc_1152() in error, and
+      also formerly png_convert_to_rfc_1123())
     png_convert_from_struct_tm() in pngwrite.c, called
       in pngwrite.c
     png_convert_from_time_t() in pngwrite.c
@@ -6028,6 +6050,19 @@ the first widely used release:
  1.6.13beta01-04     16    10613  16.so.16.13[.0]
  1.6.13rc01-02       16    10613  16.so.16.13[.0]
  1.6.13              16    10613  16.so.16.13[.0]
+ 1.6.14beta01-07     16    10614  16.so.16.14[.0]
+ 1.6.14rc01-02       16    10614  16.so.16.14[.0]
+ 1.6.14              16    10614  16.so.16.14[.0]
+ 1.6.15beta01-08     16    10615  16.so.16.15[.0]
+ 1.6.15rc01-03       16    10615  16.so.16.15[.0]
+ 1.6.15              16    10615  16.so.16.15[.0]
+ 1.6.16beta01-03     16    10616  16.so.16.16[.0]
+ 1.6.16rc01-02       16    10616  16.so.16.16[.0]
+ 1.6.16              16    10616  16.so.16.16[.0]
+ 1.6.17beta01-06     16    10617  16.so.16.17[.0]
+ 1.6.17rc01-06       16    10617  16.so.16.17[.0]
+ 1.6.17              16    10617  16.so.16.17[.0]
+ 1.6.18beta01-05     16    10618  16.so.16.18[.0]
 
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -6084,7 +6119,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.13 - August 21, 2014:
+Libpng version 1.6.18beta05 - May 31, 2015:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6107,8 +6142,8 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.13, August 21, 2014, are
-Copyright (c) 2004,2006-2014 Glenn Randers-Pehrson, and are
+libpng versions 1.2.6, August 15, 2004, through 1.6.18beta05, May 31, 2015, are
+Copyright (c) 2004,2006-2015 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
 
@@ -6206,7 +6241,7 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-August 21, 2014
+May 31, 2015
 
 .\" end of man page
 

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "August 21, 2014"
+.TH LIBPNGPF 3 "May 31, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.13
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.18beta05
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "August 21, 2014"
+.TH PNG 5 "May 31, 2015"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION

png.h

@@ -1,8 +1,9 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.13 - August 21, 2014
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * libpng version 1.6.18beta05, May 31, 2015
+ *
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -11,7 +12,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.13 - August 21, 2014: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.18beta05, May 31, 2015: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -203,6 +204,19 @@
  *    1.6.13beta01-04         16    10613  16.so.16.13[.0]
  *    1.6.13rc01-02           16    10613  16.so.16.13[.0]
  *    1.6.13                  16    10613  16.so.16.13[.0]
+ *    1.6.14beta01-07         16    10614  16.so.16.14[.0]
+ *    1.6.14rc01-02           16    10614  16.so.16.14[.0]
+ *    1.6.14                  16    10614  16.so.16.14[.0]
+ *    1.6.15beta01-08         16    10615  16.so.16.15[.0]
+ *    1.6.15rc01-03           16    10615  16.so.16.15[.0]
+ *    1.6.15                  16    10615  16.so.16.15[.0]
+ *    1.6.16beta01-03         16    10616  16.so.16.16[.0]
+ *    1.6.16rc01-02           16    10616  16.so.16.16[.0]
+ *    1.6.16                  16    10616  16.so.16.16[.0]
+ *    1.6.17beta01-06         16    10617  16.so.16.17[.0]
+ *    1.6.17rc01-06           16    10617  16.so.16.17[.0]
+ *    1.6.17                  16    10617  16.so.16.17[.0]
+ *    1.6.18beta01-05         16    10618  16.so.16.18[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -234,8 +248,8 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.13, August 21, 2014, are
- * Copyright (c) 2004, 2006-2014 Glenn Randers-Pehrson, and are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.18beta05, May 31, 2015, are
+ * Copyright (c) 2004, 2006-2015 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
  *
@@ -346,13 +360,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    August 21, 2014
+ *    May 31, 2015
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.13 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.18beta05 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
@@ -414,9 +428,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.13"
+#define PNG_LIBPNG_VER_STRING "1.6.18beta05"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.13 - August 21, 2014\n"
+     " libpng version 1.6.18beta05 - May 31, 2015\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -424,13 +438,13 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 13
+#define PNG_LIBPNG_VER_RELEASE 18
 
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
-#define PNG_LIBPNG_VER_BUILD  0
+#define PNG_LIBPNG_VER_BUILD  05
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -447,7 +461,7 @@
 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
                                        PNG_LIBPNG_BUILD_PRIVATE */
 
-#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
 
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
@@ -455,7 +469,7 @@
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10613 /* 1.6.13 */
+#define PNG_LIBPNG_VER 10618 /* 1.6.18 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -560,7 +574,7 @@ 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_13;
+typedef char* png_libpng_version_1_6_18beta05;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -1173,7 +1187,7 @@ PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
 
 /* Convert from time_t to png_time.  Uses gmtime() */
 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
-#endif /* PNG_CONVERT_tIME_SUPPORTED */
+#endif /* CONVERT_tIME */
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
@@ -1379,7 +1393,7 @@ PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
     png_uint_32 filler, int flags));
-#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
+#endif /* READ_FILLER || WRITE_FILLER */
 
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 /* Swap bytes in 16-bit depth files. */
@@ -1569,6 +1583,7 @@ PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
 #define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
 #define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
 
+#ifdef PNG_WRITE_SUPPORTED
 /* These functions give the user control over the scan-line filtering in
  * libpng and the compression methods used by zlib.  These functions are
  * mainly useful for testing, as the defaults should work with most users.
@@ -1582,6 +1597,7 @@ PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
  */
 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
     int filters));
+#endif /* WRITE */
 
 /* Flags for png_set_filter() to say which filters to use.  The flags
  * are chosen so that they don't conflict with real filter types
@@ -1607,6 +1623,7 @@ PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
 #define PNG_FILTER_VALUE_PAETH 4
 #define PNG_FILTER_VALUE_LAST  5
 
+#ifdef PNG_WRITE_SUPPORTED
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
  * defines, either the default (minimum-sum-of-absolute-differences), or
@@ -1643,7 +1660,7 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
     (png_structrp png_ptr, int heuristic_method, int num_weights,
     png_const_fixed_point_p filter_weights,
     png_const_fixed_point_p filter_costs))
-#endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+#endif /* WRITE_WEIGHTED_FILTER */
 
 /* Heuristic used for row filter selection.  These defines should NOT be
  * changed.
@@ -1653,7 +1670,6 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
 #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
 
-#ifdef PNG_WRITE_SUPPORTED
 /* Set the library compression level.  Currently, valid values range from
  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
@@ -1661,6 +1677,7 @@ PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
  * for PNG images, and do considerably fewer caclulations.  In the future,
  * these values may not correspond directly to the zlib compression levels.
  */
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
     int level));
 
@@ -1678,7 +1695,7 @@ PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
 
 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
     int method));
-#endif
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
 
 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 /* Also set zlib parameters for compressing non-IDAT chunks */
@@ -1699,7 +1716,8 @@ PNG_EXPORT(225, void, png_set_text_compression_window_bits,
 
 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
     int method));
-#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
+#endif /* WRITE */
 
 /* These next functions are called for input/output, memory, and error
  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
@@ -1810,7 +1828,7 @@ PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
  *
  * The integer return from the callback function is interpreted thus:
  *
- * negative: An error occured, png_chunk_error will be called.
+ * negative: An error occurred; png_chunk_error will be called.
  *     zero: The chunk was not handled, the chunk will be saved. A critical
  *           chunk will cause an error at this point unless it is to be saved.
  * positive: The chunk was handled, libpng will ignore/discard it.
@@ -1866,7 +1884,7 @@ PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
  */
 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
     png_bytep old_row, png_const_bytep new_row));
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PROGRESSIVE_READ */
 
 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
     png_alloc_size_t size), PNG_ALLOCATED);
@@ -2067,7 +2085,7 @@ PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
     (png_const_structrp png_ptr, png_const_inforp info_ptr));
 
-#endif /* PNG_EASY_ACCESS_SUPPORTED */
+#endif /* EASY_ACCESS */
 
 #ifdef PNG_READ_SUPPORTED
 /* Returns pointer to signature string read from PNG header */
@@ -2319,7 +2337,7 @@ PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
     png_inforp info_ptr, int unit,
     png_const_charp swidth, png_const_charp sheight));
-#endif /* PNG_sCAL_SUPPORTED */
+#endif /* sCAL */
 
 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 /* Provide the default handling for all unknown chunks or, optionally, for
@@ -2547,8 +2565,8 @@ PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
     png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
     int *unit_type));
-#  endif /* PNG_pHYs_SUPPORTED */
-#endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
+#  endif /* pHYs */
+#endif  /* INCH_CONVERSIONS */
 
 /* Added in libpng-1.4.0 */
 #ifdef PNG_IO_STATE_SUPPORTED
@@ -2571,7 +2589,7 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
 #  define PNG_IO_CHUNK_CRC   0x0080   /* currently at the chunk crc */
 #  define PNG_IO_MASK_OP     0x000f   /* current operation: reading/writing */
 #  define PNG_IO_MASK_LOC    0x00f0   /* current location: sig/hdr/data/crc */
-#endif /* ?PNG_IO_STATE_SUPPORTED */
+#endif /* IO_STATE */
 
 /* Interlace support.  The following macros are always defined so that if
  * libpng interlace handling is turned off the macros may be used to handle
@@ -2655,27 +2673,29 @@ PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
            * (png_uint_16)(alpha)                         \
            + (png_uint_16)(bg)*(png_uint_16)(255          \
            - (png_uint_16)(alpha)) + 128);                \
-       (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
+       (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)(alpha)                          \
            + (png_uint_32)(bg)*(65535                      \
            - (png_uint_32)(alpha)) + 32768);               \
-       (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
+       (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); }
 
 #else  /* Standard method using integer division */
 
-#  define png_composite(composite, fg, alpha, bg)                          \
-     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +  \
-     (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
-     127) / 255)
+#  define png_composite(composite, fg, alpha, bg)                        \
+     (composite) =                                                       \
+         (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) +  \
+         (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+         127) / 255))
 
 #  define png_composite_16(composite, fg, alpha, bg)                         \
-     (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
-     (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) +         \
-     32767) / 65535)
-#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
+     (composite) =                                                           \
+         (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
+         (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) +     \
+         32767) / 65535))
+#endif /* READ_COMPOSITE_NODIV */
 
 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
@@ -2745,6 +2765,8 @@ PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
 #  endif
 #endif
 
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
+    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
 /*******************************************************************************
  *  SIMPLIFIED API
  *******************************************************************************
@@ -2762,8 +2784,9 @@ PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
  *
  * To read a PNG file using the simplified API:
  *
- * 1) Declare a 'png_image' structure (see below) on the stack and set the
- *    version field to PNG_IMAGE_VERSION.
+ * 1) Declare a 'png_image' structure (see below) on the stack, set the
+ *    version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
+ *    (this is REQUIRED, your program may crash if you don't do it.)
  * 2) Call the appropriate png_image_begin_read... function.
  * 3) Set the png_image 'format' member to the required sample format.
  * 4) Allocate a buffer for the image and, if required, the color-map.
@@ -2816,7 +2839,7 @@ typedef struct
 #  define PNG_IMAGE_WARNING 1
 #  define PNG_IMAGE_ERROR 2
    /*
-    * The result is a two bit code such that a value more than 1 indicates
+    * The result is a two-bit code such that a value more than 1 indicates
     * a failure in the API just called:
     *
     *    0 - no warning or error
@@ -3101,7 +3124,7 @@ PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
    FILE* file));
    /* The PNG header is read from the stdio FILE object. */
-#endif /* PNG_STDIO_SUPPORTED */
+#endif /* STDIO */
 
 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
    png_const_voidp memory, png_size_t size));
@@ -3146,7 +3169,7 @@ PNG_EXPORT(238, void, png_image_free, (png_imagep image));
    /* Free any data allocated by libpng in image->opaque, setting the pointer to
     * NULL.  May be called at any time after the structure is initialized.
     */
-#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */
+#endif /* SIMPLIFIED_READ */
 
 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
 #ifdef PNG_STDIO_SUPPORTED
@@ -3188,15 +3211,18 @@ PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
  *
  * With all APIs row_stride is handled as in the read APIs - it is the spacing
  * from one row to the next in component sized units (1 or 2 bytes) and if
- * negative indicates a bottom-up row layout in the buffer.
+ * negative indicates a bottom-up row layout in the buffer.  If row_stride is zero,
+ * libpng will calculate it for you from the image width and number of channels.
  *
- * Note that the write API does not support interlacing or sub-8-bit pixels.
+ * Note that the write API does not support interlacing, sub-8-bit pixels, indexed
+ * PNG (color_type 3) or most ancillary chunks.
  */
-#endif /* PNG_STDIO_SUPPORTED */
-#endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */
+#endif /* STDIO */
+#endif /* SIMPLIFIED_WRITE */
 /*******************************************************************************
  *  END OF SIMPLIFIED API
  ******************************************************************************/
+#endif /* SIMPLIFIED_{READ|WRITE} */
 
 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
 PNG_EXPORT(242, void, png_set_check_for_invalid_index,
@@ -3244,19 +3270,18 @@ PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
 
 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
    int onoff));
-#endif
+#endif /* SET_OPTION */
 
 /*******************************************************************************
  *  END OF HARDWARE AND SOFTWARE OPTIONS
  ******************************************************************************/
 
-/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
- * defs, scripts/pnglibconf.h, and scripts/pnglibconf.h.prebuilt
+/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
+ * defs, and in scripts/symbols.def.
  */
 
 /* The last ordinal number (this is the *last* one already used; the next
- * one to use is one more than this.)  Maintainer, remember to add an entry to
- * scripts/symbols.def as well.
+ * one to use is one more than this.)
  */
 #ifdef PNG_EXPORT_LAST_ORDINAL
   PNG_EXPORT_LAST_ORDINAL(244);

pngconf.h

@@ -1,9 +1,9 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.13 - August 21, 2014
+ * libpng version 1.6.18beta05, (PENDING RELEASE)
  *
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -11,9 +11,7 @@
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  *
- */
-
-/* Any machine specific code is near the front of this file, so if you
+ * Any machine specific code is near the front of this file, so if you
  * are configuring libpng for a machine, you may want to read the section
  * starting here down to where it starts to typedef png_color, png_text,
  * and png_info.
@@ -22,26 +20,6 @@
 #ifndef PNGCONF_H
 #define PNGCONF_H
 
-/* To do: Do all of this in scripts/pnglibconf.dfa */
-#ifdef PNG_SAFE_LIMITS_SUPPORTED
-#  ifdef PNG_USER_WIDTH_MAX
-#    undef PNG_USER_WIDTH_MAX
-#    define PNG_USER_WIDTH_MAX 1000000L
-#  endif
-#  ifdef PNG_USER_HEIGHT_MAX
-#    undef PNG_USER_HEIGHT_MAX
-#    define PNG_USER_HEIGHT_MAX 1000000L
-#  endif
-#  ifdef PNG_USER_CHUNK_MALLOC_MAX
-#    undef PNG_USER_CHUNK_MALLOC_MAX
-#    define PNG_USER_CHUNK_MALLOC_MAX 4000000L
-#  endif
-#  ifdef PNG_USER_CHUNK_CACHE_MAX
-#    undef PNG_USER_CHUNK_CACHE_MAX
-#    define PNG_USER_CHUNK_CACHE_MAX 128
-#  endif
-#endif
-
 #ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */
 
 /* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C

pngdebug.h

@@ -1,12 +1,11 @@
 
 /* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
  *
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 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.)
  *
- * Last changed in libpng 1.6.8 [December 19, 2013]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h

pngerror.c

@@ -1,7 +1,7 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.6.13 [August 21, 2014]
+ * Last changed in libpng 1.6.15 [November 20, 2014]
  * Copyright (c) 1998-2014 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.)
@@ -27,7 +27,7 @@ static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
 static void /* PRIVATE */
 png_default_warning PNGARG((png_const_structrp png_ptr,
    png_const_charp warning_message));
-#endif /* PNG_WARNINGS_SUPPORTED */
+#endif /* WARNINGS */
 
 /* This function is called whenever there is a fatal error.  This function
  * should not be changed.  If there is a need to handle errors differently,
@@ -43,8 +43,8 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
    char msg[16];
    if (png_ptr != NULL)
    {
-      if (png_ptr->flags&
-         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+      if ((png_ptr->flags &
+         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0
       {
          if (*error_message == PNG_LITERAL_SHARP)
          {
@@ -54,7 +54,7 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
                if (error_message[offset] == ' ')
                   break;
 
-            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
             {
                int i;
                for (i = 0; i < offset - 1; i++)
@@ -69,7 +69,7 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
 
       else
       {
-         if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+         if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
          {
             msg[0] = '0';
             msg[1] = '\0';
@@ -103,7 +103,7 @@ png_err,(png_const_structrp png_ptr),PNG_NORETURN)
       use the default handler, which will not return. */
    png_default_error(png_ptr, "");
 }
-#endif /* PNG_ERROR_TEXT_SUPPORTED */
+#endif /* ERROR_TEXT */
 
 /* Utility to safely appends strings to a buffer.  This never errors out so
  * error checking is not required in the caller.
@@ -152,7 +152,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
          case PNG_NUMBER_FORMAT_fixed:
             /* Needs five digits (the fraction) */
             mincount = 5;
-            if (output || number % 10 != 0)
+            if (output != 0 || number % 10 != 0)
             {
                *--end = digits[number % 10];
                output = 1;
@@ -189,7 +189,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
       ++count;
 
       /* Float a fixed number here: */
-      if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
+      if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start))
       {
          /* End of the fraction, but maybe nothing was output?  In that case
           * drop the decimal point.  If the number is a true zero handle that
@@ -219,8 +219,8 @@ png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
    if (png_ptr != NULL)
    {
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   if (png_ptr->flags&
-       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+   if ((png_ptr->flags &
+       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
 #endif
       {
          if (*warning_message == PNG_LITERAL_SHARP)
@@ -355,13 +355,13 @@ png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
     */
    png_warning(png_ptr, msg);
 }
-#endif /* PNG_WARNINGS_SUPPORTED */
+#endif /* WARNINGS */
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 void PNGAPI
 png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
 {
-   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
    {
 #     ifdef PNG_READ_SUPPORTED
          if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
@@ -391,7 +391,7 @@ png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
 void /* PRIVATE */
 png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
 {
-  if (png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN)
+  if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)
      png_warning(png_ptr, error_message);
   else
      png_error(png_ptr, error_message);
@@ -404,7 +404,7 @@ png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
 void /* PRIVATE */
 png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
 {
-  if (png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN)
+  if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)
      png_warning(png_ptr, error_message);
   else
      png_error(png_ptr, error_message);
@@ -442,7 +442,7 @@ png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
       int c = (int)(chunk_name >> ishift) & 0xff;
 
       ishift -= 8;
-      if (isnonalpha(c))
+      if (isnonalpha(c) != 0)
       {
          buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
@@ -473,7 +473,7 @@ png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
       buffer[iout] = '\0';
    }
 }
-#endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
+#endif /* WARNINGS || ERROR_TEXT */
 
 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
 PNG_FUNCTION(void,PNGAPI
@@ -490,7 +490,7 @@ png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
       png_error(png_ptr, msg);
    }
 }
-#endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
+#endif /* READ && ERROR_TEXT */
 
 #ifdef PNG_WARNINGS_SUPPORTED
 void PNGAPI
@@ -506,7 +506,7 @@ png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
       png_warning(png_ptr, msg);
    }
 }
-#endif /* PNG_WARNINGS_SUPPORTED */
+#endif /* WARNINGS */
 
 #ifdef PNG_READ_SUPPORTED
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
@@ -514,7 +514,7 @@ void PNGAPI
 png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
     error_message)
 {
-   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
       png_chunk_warning(png_ptr, error_message);
 
    else
@@ -525,7 +525,7 @@ png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
 #  endif
 }
 #endif
-#endif /* PNG_READ_SUPPORTED */
+#endif /* READ */
 
 void /* PRIVATE */
 png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
@@ -538,7 +538,7 @@ png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
     * unconditionally does the right thing.
     */
 #  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
-      if (png_ptr->mode & PNG_IS_READ_STRUCT)
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
 #  endif
 
 #  ifdef PNG_READ_SUPPORTED
@@ -552,7 +552,7 @@ png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
 #  endif
 
 #  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
-      else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
+      else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
 #  endif
 
 #  ifdef PNG_WRITE_SUPPORTED
@@ -577,11 +577,12 @@ png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
    char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
    memcpy(msg, fixed_message, fixed_message_ln);
    iin = 0;
-   if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
-   {
-      msg[fixed_message_ln + iin] = name[iin];
-      ++iin;
-   }
+   if (name != NULL)
+      while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
+      {
+         msg[fixed_message_ln + iin] = name[iin];
+         ++iin;
+      }
    msg[fixed_message_ln + iin] = 0;
    png_error(png_ptr, msg);
 }
@@ -757,7 +758,8 @@ PNG_FUNCTION(void,PNGAPI
 png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
 {
 #ifdef PNG_SETJMP_SUPPORTED
-   if (png_ptr && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
+   if (png_ptr != NULL && png_ptr->longjmp_fn != NULL &&
+       png_ptr->jmp_buf_ptr != NULL)
       png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
 #else
    PNG_UNUSED(png_ptr)
@@ -822,7 +824,7 @@ png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 #endif
    PNG_UNUSED(png_ptr) /* Make compiler happy */
 }
-#endif /* PNG_WARNINGS_SUPPORTED */
+#endif /* WARNINGS */
 
 /* This function is called when the application wants to use another method
  * of handling errors and warnings.  Note that the error function MUST NOT
@@ -957,5 +959,5 @@ png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
 
    return result;
 }
-#endif /* SIMPLIFIED READ/WRITE */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */
+#endif /* READ || WRITE */

pngget.c

@@ -1,8 +1,8 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.6.11 [June 5, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -116,7 +116,8 @@ png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
    info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
       {
          png_debug1(1, "in %s retrieval function",
              "png_get_x_pixels_per_meter");
@@ -137,7 +138,8 @@ png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
     info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       png_debug1(1, "in %s retrieval function",
           "png_get_y_pixels_per_meter");
@@ -157,7 +159,8 @@ png_uint_32 PNGAPI
 png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
 
@@ -179,7 +182,8 @@ png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
    info_ptr)
 {
 #ifdef PNG_READ_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
 
@@ -202,10 +206,11 @@ png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
     png_const_inforp info_ptr)
 {
 #ifdef PNG_READ_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)
-       && info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0
-       && info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX
-       && info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0 &&
+       info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 &&
+       info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX &&
+       info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
    {
       png_fixed_point res;
 
@@ -215,7 +220,7 @@ png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
        * range of 0..2^31-1; otherwise the cast might overflow.
        */
       if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
-          (png_int_32)info_ptr->x_pixels_per_unit))
+          (png_int_32)info_ptr->x_pixels_per_unit) != 0)
          return res;
    }
 #else
@@ -231,7 +236,8 @@ png_int_32 PNGAPI
 png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
 
@@ -250,7 +256,8 @@ png_int_32 PNGAPI
 png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
 
@@ -269,7 +276,8 @@ png_int_32 PNGAPI
 png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels");
 
@@ -288,7 +296,8 @@ png_int_32 PNGAPI
 png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels");
 
@@ -328,7 +337,7 @@ ppi_from_ppm(png_uint_32 ppm)
     */
    png_fixed_point result;
    if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
-       5000))
+       5000) != 0)
       return result;
 
    /* Overflow. */
@@ -414,7 +423,8 @@ png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_uint_32 retval = 0;
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "pHYs");
 
@@ -445,12 +455,12 @@ png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
    return (retval);
 }
-#endif /* PNG_pHYs_SUPPORTED */
-#endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
+#endif /* pHYs */
+#endif  /* INCH_CONVERSIONS */
 
 /* png_get_channels really belongs in here, too, but it's been around longer */
 
-#endif  /* PNG_EASY_ACCESS_SUPPORTED */
+#endif  /* EASY_ACCESS */
 
 
 png_byte PNGAPI
@@ -478,8 +488,9 @@ png_uint_32 PNGAPI
 png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
    png_color_16p *background)
 {
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
-       && background != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_bKGD) != 0 &&
+       background != NULL)
    {
       png_debug1(1, "in %s retrieval function", "bKGD");
 
@@ -509,7 +520,7 @@ png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
     * consistent.
     */
    if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
    {
       png_debug1(1, "in %s retrieval function", "cHRM");
 
@@ -550,7 +561,7 @@ png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
    double *blue_Z)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
    {
       png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
 
@@ -598,7 +609,7 @@ png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_fixed_point *int_blue_Z)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
    {
       png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
 
@@ -635,7 +646,7 @@ png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_debug1(1, "in %s retrieval function", "cHRM");
 
    if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
    {
       if (white_x != NULL)
          *white_x = info_ptr->colorspace.end_points_xy.whitex;
@@ -670,7 +681,7 @@ png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_debug1(1, "in %s retrieval function", "gAMA");
 
    if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
       file_gamma != NULL)
    {
       *file_gamma = info_ptr->colorspace.gamma;
@@ -689,7 +700,7 @@ png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_debug1(1, "in %s retrieval function", "gAMA(float)");
 
    if (png_ptr != NULL && info_ptr != NULL &&
-      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
       file_gamma != NULL)
    {
       *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
@@ -709,8 +720,8 @@ png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "sRGB");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
-       && file_srgb_intent != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->valid & PNG_INFO_sRGB) != 0 && file_srgb_intent != NULL)
    {
       *file_srgb_intent = info_ptr->colorspace.rendering_intent;
       return (PNG_INFO_sRGB);
@@ -728,9 +739,10 @@ png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "iCCP");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
-       && name != NULL && compression_type != NULL && profile != NULL &&
-		 proflen != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_iCCP) != 0 &&
+       name != NULL && compression_type != NULL && profile != NULL &&
+           proflen != NULL)
    {
       *name = info_ptr->iccp_name;
       *profile = info_ptr->iccp_profile;
@@ -768,8 +780,8 @@ png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "hIST");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
-       && hist != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL)
    {
       *hist = info_ptr->hist;
       return (PNG_INFO_hIST);
@@ -787,14 +799,20 @@ png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "IHDR");
 
-   if (png_ptr == NULL || info_ptr == NULL || width == NULL ||
-       height == NULL || bit_depth == NULL || color_type == NULL)
+   if (png_ptr == NULL || info_ptr == NULL)
       return (0);
 
-   *width = info_ptr->width;
-   *height = info_ptr->height;
-   *bit_depth = info_ptr->bit_depth;
-   *color_type = info_ptr->color_type;
+   if (width != NULL)
+       *width = info_ptr->width;
+
+   if (height != NULL)
+       *height = info_ptr->height;
+
+   if (bit_depth != NULL)
+       *bit_depth = info_ptr->bit_depth;
+
+   if (color_type != NULL)
+       *color_type = info_ptr->color_type;
 
    if (compression_type != NULL)
       *compression_type = info_ptr->compression_type;
@@ -824,8 +842,9 @@ png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "oFFs");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
-       && offset_x != NULL && offset_y != NULL && unit_type != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0 &&
+       offset_x != NULL && offset_y != NULL && unit_type != NULL)
    {
       *offset_x = info_ptr->x_offset;
       *offset_y = info_ptr->y_offset;
@@ -845,8 +864,9 @@ png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "pCAL");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)
-       && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pCAL) != 0 &&
+       purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
        nparams != NULL && units != NULL && params != NULL)
    {
       *purpose = info_ptr->pcal_purpose;
@@ -872,7 +892,7 @@ png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, png_fixed_point *width, png_fixed_point *height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->valid & PNG_INFO_sCAL))
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
    {
       *unit = info_ptr->scal_unit;
       /*TODO: make this work without FP support; the API is currently eliminated
@@ -895,7 +915,7 @@ png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, double *width, double *height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->valid & PNG_INFO_sCAL))
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
    {
       *unit = info_ptr->scal_unit;
       *width = atof(info_ptr->scal_s_width);
@@ -911,7 +931,7 @@ png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, png_charpp width, png_charpp height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->valid & PNG_INFO_sCAL))
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
    {
       *unit = info_ptr->scal_unit;
       *width = info_ptr->scal_s_width;
@@ -933,7 +953,7 @@ png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_debug1(1, "in %s retrieval function", "pHYs");
 
    if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->valid & PNG_INFO_pHYs))
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       if (res_x != NULL)
       {
@@ -964,8 +984,8 @@ png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "PLTE");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
-       && palette != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_PLTE) != 0 && palette != NULL)
    {
       *palette = info_ptr->palette;
       *num_palette = info_ptr->num_palette;
@@ -983,8 +1003,8 @@ png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "sBIT");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
-       && sig_bit != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sBIT) != 0 && sig_bit != NULL)
    {
       *sig_bit = &(info_ptr->sig_bit);
       return (PNG_INFO_sBIT);
@@ -1027,8 +1047,8 @@ png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "tIME");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)
-       && mod_time != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL)
    {
       *mod_time = &(info_ptr->mod_time);
       return (PNG_INFO_tIME);
@@ -1044,7 +1064,8 @@ png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
     png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
 {
    png_uint_32 retval = 0;
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_tRNS) != 0)
    {
       png_debug1(1, "in %s retrieval function", "tRNS");
 
@@ -1120,21 +1141,21 @@ png_get_compression_buffer_size(png_const_structrp png_ptr)
    if (png_ptr == NULL)
       return 0;
 
-#  ifdef PNG_WRITE_SUPPORTED
-      if (png_ptr->mode & PNG_IS_READ_STRUCT)
-#  endif
+#ifdef PNG_WRITE_SUPPORTED
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+#endif
    {
-#     ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
          return png_ptr->IDAT_read_size;
-#     else
+#else
          return PNG_IDAT_READ_SIZE;
-#     endif
+#endif
    }
 
-#  ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_SUPPORTED
       else
          return png_ptr->zbuffer_size;
-#  endif
+#endif
 }
 
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
@@ -1165,7 +1186,7 @@ png_get_chunk_malloc_max (png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
 }
-#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+#endif /* SET_USER_LIMITS */
 
 /* These functions were added to libpng 1.4.0 */
 #ifdef PNG_IO_STATE_SUPPORTED
@@ -1180,7 +1201,7 @@ png_get_io_chunk_type (png_const_structrp png_ptr)
 {
    return png_ptr->chunk_name;
 }
-#endif /* ?PNG_IO_STATE_SUPPORTED */
+#endif /* IO_STATE */
 
 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
 #  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
@@ -1195,4 +1216,4 @@ png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr)
 #  endif
 #endif
 
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+#endif /* READ || WRITE */

pnginfo.h

@@ -1,12 +1,11 @@
 
 /* pnginfo.h - header file for PNG reference library
  *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
  * Copyright (c) 1998-2013 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.)
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -121,7 +120,7 @@ struct png_info_def
    int num_text; /* number of comments read or comments to write */
    int max_text; /* current size of text array */
    png_textp text; /* array of comments read or comments to write */
-#endif /* PNG_TEXT_SUPPORTED */
+#endif /* TEXT */
 
 #ifdef PNG_tIME_SUPPORTED
    /* The tIME chunk holds the last time the displayed image data was

pngmem.c

@@ -1,8 +1,8 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.6.8 [December 19, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Copyright (c) 1998-2014 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.)
  *
@@ -41,7 +41,7 @@ png_destroy_png_struct(png_structrp png_ptr)
 }
 
 /* Allocate memory.  For reasonable files, size should never exceed
- * 64K.  However, zlib may allocate more then 64K if you don't tell
+ * 64K.  However, zlib may allocate more than 64K if you don't tell
  * it not to.  See zconf.h and png.h for more information.  zlib does
  * need to allocate exactly 64K, so whatever you call here must
  * have the ability to do that.
@@ -77,6 +77,9 @@ png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
    PNG_UNUSED(png_ptr)
 #endif
 
+   /* Some compilers complain that this is always true.  However, it
+    * can be false when integer overflow happens.
+    */
    if (size > 0 && size <= PNG_SIZE_MAX
 #     ifdef PNG_MAX_MALLOC_64K
          && size <= 65536U
@@ -199,7 +202,7 @@ png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
 
    return ret;
 }
-#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* USER_MEM */
 
 /* This function was added at libpng version 1.2.3.  The png_malloc_warn()
  * function will issue a png_warning and return NULL instead of issuing a
@@ -244,7 +247,7 @@ png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
-#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* USER_MEM */
 
    free(ptr);
 }
@@ -277,5 +280,5 @@ png_get_mem_ptr(png_const_structrp png_ptr)
 
    return png_ptr->mem_ptr;
 }
-#endif /* PNG_USER_MEM_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+#endif /* USER_MEM */
+#endif /* READ || WRITE */

pngpread.c

@@ -1,8 +1,8 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.6.11 [June 5, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -26,6 +26,13 @@
 #define PNG_READ_iTXt_MODE  7
 #define PNG_ERROR_MODE      8
 
+#define PNG_PUSH_SAVE_BUFFER_IF_FULL \
+if (png_ptr->push_length + 4 > png_ptr->buffer_size) \
+   { png_push_save_buffer(png_ptr); return; }
+#define PNG_PUSH_SAVE_BUFFER_IF_LT(N) \
+if (png_ptr->buffer_size < N) \
+   { png_push_save_buffer(png_ptr); return; }
+
 void PNGAPI
 png_process_data(png_structrp png_ptr, png_inforp info_ptr,
     png_bytep buffer, png_size_t buffer_size)
@@ -46,7 +53,7 @@ png_process_data_pause(png_structrp png_ptr, int save)
 {
    if (png_ptr != NULL)
    {
-      /* It's easiest for the caller if we do the save, then the caller doesn't
+      /* It's easiest for the caller if we do the save; then the caller doesn't
        * have to supply the same data again:
        */
       if (save != 0)
@@ -189,23 +196,18 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
    int keep; /* unknown handling method */
 #endif
 
-   /* First we make sure we have enough data for the 4 byte chunk name
-    * and the 4 byte chunk length before proceeding with decoding the
+   /* First we make sure we have enough data for the 4-byte chunk name
+    * and the 4-byte chunk length before proceeding with decoding the
     * chunk data.  To fully decode each of these chunks, we also make
-    * sure we have enough data in the buffer for the 4 byte CRC at the
+    * sure we have enough data in the buffer for the 4-byte CRC at the
     * end of every chunk (except IDAT, which is handled separately).
     */
-   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+   if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
    {
       png_byte chunk_length[4];
       png_byte chunk_tag[4];
 
-      if (png_ptr->buffer_size < 8)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_LT(8)
       png_push_fill_buffer(png_ptr, chunk_length, 4);
       png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
@@ -219,28 +221,28 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
    if (chunk_name == png_IDAT)
    {
-      if (png_ptr->mode & PNG_AFTER_IDAT)
+      if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
          png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 
       /* If we reach an IDAT chunk, this means we have read all of the
        * header chunks, and we can start reading the image (or if this
        * is called after the image has been read - we have an error).
        */
-      if (!(png_ptr->mode & PNG_HAVE_IHDR))
+      if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
          png_error(png_ptr, "Missing IHDR before IDAT");
 
       else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-          !(png_ptr->mode & PNG_HAVE_PLTE))
+          (png_ptr->mode & PNG_HAVE_PLTE) == 0)
          png_error(png_ptr, "Missing PLTE before IDAT");
 
       png_ptr->mode |= PNG_HAVE_IDAT;
       png_ptr->process_mode = PNG_READ_IDAT_MODE;
 
-      if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+      if ((png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) == 0)
          if (png_ptr->push_length == 0)
             return;
 
-      if (png_ptr->mode & PNG_AFTER_IDAT)
+      if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
          png_benign_error(png_ptr, "Too many IDATs found");
    }
 
@@ -249,23 +251,13 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
       if (png_ptr->push_length != 13)
          png_error(png_ptr, "Invalid IHDR length");
 
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
    }
 
    else if (chunk_name == png_IEND)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
 
       png_ptr->process_mode = PNG_READ_DONE_MODE;
@@ -275,12 +267,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
    else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
 
       if (chunk_name == png_PLTE)
@@ -290,11 +277,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
    else if (chunk_name == png_PLTE)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -313,12 +296,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_gAMA_SUPPORTED
    else if (png_ptr->chunk_name == png_gAMA)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -326,12 +304,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_sBIT_SUPPORTED
    else if (png_ptr->chunk_name == png_sBIT)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -339,12 +312,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_cHRM_SUPPORTED
    else if (png_ptr->chunk_name == png_cHRM)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -352,12 +320,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_sRGB_SUPPORTED
    else if (chunk_name == png_sRGB)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -365,12 +328,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_iCCP_SUPPORTED
    else if (png_ptr->chunk_name == png_iCCP)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -378,12 +336,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_sPLT_SUPPORTED
    else if (chunk_name == png_sPLT)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -391,12 +344,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_tRNS_SUPPORTED
    else if (chunk_name == png_tRNS)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -404,12 +352,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_bKGD_SUPPORTED
    else if (chunk_name == png_bKGD)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -417,12 +360,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_hIST_SUPPORTED
    else if (chunk_name == png_hIST)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -430,12 +368,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_pHYs_SUPPORTED
    else if (chunk_name == png_pHYs)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -443,12 +376,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_oFFs_SUPPORTED
    else if (chunk_name == png_oFFs)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
    }
 #endif
@@ -456,12 +384,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_pCAL_SUPPORTED
    else if (chunk_name == png_pCAL)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -469,12 +392,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_sCAL_SUPPORTED
    else if (chunk_name == png_sCAL)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -482,12 +400,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_tIME_SUPPORTED
    else if (chunk_name == png_tIME)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -495,12 +408,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_tEXt_SUPPORTED
    else if (chunk_name == png_tEXt)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -508,12 +416,7 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_zTXt_SUPPORTED
    else if (chunk_name == png_zTXt)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 
@@ -521,23 +424,14 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_READ_iTXt_SUPPORTED
    else if (chunk_name == png_iTXt)
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
 #endif
 
    else
    {
-      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
+      PNG_PUSH_SAVE_BUFFER_IF_FULL
       png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
          PNG_HANDLE_CHUNK_AS_DEFAULT);
    }
@@ -555,7 +449,7 @@ png_push_crc_skip(png_structrp png_ptr, png_uint_32 skip)
 void /* PRIVATE */
 png_push_crc_finish(png_structrp png_ptr)
 {
-   if (png_ptr->skip_length && png_ptr->save_buffer_size)
+   if (png_ptr->skip_length != 0 && png_ptr->save_buffer_size != 0)
    {
       png_size_t save_size = png_ptr->save_buffer_size;
       png_uint_32 skip_length = png_ptr->skip_length;
@@ -579,7 +473,7 @@ png_push_crc_finish(png_structrp png_ptr)
       png_ptr->save_buffer_size -= save_size;
       png_ptr->save_buffer_ptr += save_size;
    }
-   if (png_ptr->skip_length && png_ptr->current_buffer_size)
+   if (png_ptr->skip_length != 0 && png_ptr->current_buffer_size != 0)
    {
       png_size_t save_size = png_ptr->current_buffer_size;
       png_uint_32 skip_length = png_ptr->skip_length;
@@ -600,14 +494,9 @@ png_push_crc_finish(png_structrp png_ptr)
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
    }
-   if (!png_ptr->skip_length)
+   if (png_ptr->skip_length == 0)
    {
-      if (png_ptr->buffer_size < 4)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_LT(4)
       png_crc_finish(png_ptr, 0);
       png_ptr->process_mode = PNG_READ_CHUNK_MODE;
    }
@@ -622,7 +511,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       return;
 
    ptr = buffer;
-   if (png_ptr->save_buffer_size)
+   if (png_ptr->save_buffer_size != 0)
    {
       png_size_t save_size;
 
@@ -639,7 +528,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       png_ptr->save_buffer_size -= save_size;
       png_ptr->save_buffer_ptr += save_size;
    }
-   if (length && png_ptr->current_buffer_size)
+   if (length != 0 && png_ptr->current_buffer_size != 0)
    {
       png_size_t save_size;
 
@@ -659,7 +548,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
 void /* PRIVATE */
 png_push_save_buffer(png_structrp png_ptr)
 {
-   if (png_ptr->save_buffer_size)
+   if (png_ptr->save_buffer_size != 0)
    {
       if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
       {
@@ -726,18 +615,13 @@ png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer,
 void /* PRIVATE */
 png_push_read_IDAT(png_structrp png_ptr)
 {
-   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+   if ((png_ptr->mode & PNG_HAVE_CHUNK_HEADER) == 0)
    {
       png_byte chunk_length[4];
       png_byte chunk_tag[4];
 
       /* TODO: this code can be commoned up with the same code in push_read */
-      if (png_ptr->buffer_size < 8)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_LT(8)
       png_push_fill_buffer(png_ptr, chunk_length, 4);
       png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
@@ -749,7 +633,7 @@ png_push_read_IDAT(png_structrp png_ptr)
       {
          png_ptr->process_mode = PNG_READ_CHUNK_MODE;
 
-         if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+         if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
             png_error(png_ptr, "Not enough compressed data");
 
          return;
@@ -758,7 +642,7 @@ png_push_read_IDAT(png_structrp png_ptr)
       png_ptr->idat_size = png_ptr->push_length;
    }
 
-   if (png_ptr->idat_size && png_ptr->save_buffer_size)
+   if (png_ptr->idat_size != 0 && png_ptr->save_buffer_size != 0)
    {
       png_size_t save_size = png_ptr->save_buffer_size;
       png_uint_32 idat_size = png_ptr->idat_size;
@@ -785,7 +669,7 @@ png_push_read_IDAT(png_structrp png_ptr)
       png_ptr->save_buffer_ptr += save_size;
    }
 
-   if (png_ptr->idat_size && png_ptr->current_buffer_size)
+   if (png_ptr->idat_size != 0 && png_ptr->current_buffer_size != 0)
    {
       png_size_t save_size = png_ptr->current_buffer_size;
       png_uint_32 idat_size = png_ptr->idat_size;
@@ -810,14 +694,9 @@ png_push_read_IDAT(png_structrp png_ptr)
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
    }
-   if (!png_ptr->idat_size)
+   if (png_ptr->idat_size == 0)
    {
-      if (png_ptr->buffer_size < 4)
-      {
-         png_push_save_buffer(png_ptr);
-         return;
-      }
-
+      PNG_PUSH_SAVE_BUFFER_IF_LT(4)
       png_crc_finish(png_ptr, 0);
       png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
       png_ptr->mode |= PNG_AFTER_IDAT;
@@ -845,7 +724,7 @@ png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
     * or the stream marked as finished.
     */
    while (png_ptr->zstream.avail_in > 0 &&
-      !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
+      (png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
    {
       int ret;
 
@@ -962,7 +841,7 @@ png_push_process_row(png_structrp png_ptr)
    memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
 
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
-   if (png_ptr->transformations)
+   if (png_ptr->transformations != 0)
       png_do_read_transformations(png_ptr, &row_info);
 #endif
 
@@ -980,7 +859,8 @@ png_push_process_row(png_structrp png_ptr)
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Expand interlaced rows to full size */
-   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+   if (png_ptr->interlaced != 0 &&
+       (png_ptr->transformations & PNG_INTERLACE) != 0)
    {
       if (png_ptr->pass < 6)
          png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
@@ -1154,6 +1034,7 @@ png_push_process_row(png_structrp png_ptr)
       }
    }
    else
+#endif
    {
       png_push_have_row(png_ptr, png_ptr->row_buf + 1);
       png_read_push_finish_row(png_ptr);
@@ -1163,6 +1044,7 @@ png_push_process_row(png_structrp png_ptr)
 void /* PRIVATE */
 png_read_push_finish_row(png_structrp png_ptr)
 {
+#ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
@@ -1187,7 +1069,8 @@ png_read_push_finish_row(png_structrp png_ptr)
    if (png_ptr->row_number < png_ptr->num_rows)
       return;
 
-   if (png_ptr->interlaced)
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+   if (png_ptr->interlaced != 0)
    {
       png_ptr->row_number = 0;
       memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
@@ -1211,7 +1094,7 @@ png_read_push_finish_row(png_structrp png_ptr)
              png_pass_start[png_ptr->pass]) /
              png_pass_inc[png_ptr->pass];
 
-         if (png_ptr->transformations & PNG_INTERLACE)
+         if ((png_ptr->transformations & PNG_INTERLACE) != 0)
             break;
 
          png_ptr->num_rows = (png_ptr->height +
@@ -1221,6 +1104,7 @@ png_read_push_finish_row(png_structrp png_ptr)
 
       } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
    }
+#endif /* READ_INTERLACING */
 }
 
 void /* PRIVATE */
@@ -1245,6 +1129,7 @@ png_push_have_row(png_structrp png_ptr, png_bytep row)
          (int)png_ptr->pass);
 }
 
+#ifdef PNG_READ_INTERLACING_SUPPORTED
 void PNGAPI
 png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
     png_const_bytep new_row)
@@ -1259,6 +1144,7 @@ png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
    if (new_row != NULL)
       png_combine_row(png_ptr, old_row, 1/*blocky display*/);
 }
+#endif /* READ_INTERLACING */
 
 void PNGAPI
 png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
@@ -1283,4 +1169,4 @@ png_get_progressive_ptr(png_const_structrp png_ptr)
 
    return png_ptr->io_ptr;
 }
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PROGRESSIVE_READ */

pngpriv.h

@@ -1,13 +1,11 @@
 
 /* pngpriv.h - private declarations for use inside libpng
  *
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.6.10 [March 6, 1014]]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -120,8 +118,12 @@
     * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
     * off.
     *
-    * Note that gcc-4.9 defines __ARM_NEON instead of __ARM_NEON__, so we
-    * check both variants.
+    * Note that gcc-4.9 defines __ARM_NEON instead of the deprecated
+    * __ARM_NEON__, so we check both variants.
+    *
+    * To disable ARM_NEON optimizations entirely, and skip compiling the
+    * associated assembler code, pass --enable-arm-neon=no to configure
+    * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
     */
 #  if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && \
    defined(PNG_ALIGNED_MEMORY_SUPPORTED)
@@ -172,7 +174,7 @@
           */
 #        define PNG_ARM_NEON_IMPLEMENTATION 2
 #     endif /* __ARM_NEON__ */
-#  endif /* !defined PNG_ARM_NEON_IMPLEMENTATION */
+#  endif /* !PNG_ARM_NEON_IMPLEMENTATION */
 
 #  ifndef PNG_ARM_NEON_IMPLEMENTATION
       /* Use the intrinsics code by default. */
@@ -298,48 +300,27 @@
 #  define PNG_DLL_EXPORT
 #endif
 
-/* SECURITY and SAFETY:
+/* This is a global switch to set the compilation for an installed system
+ * (a release build).  It can be set for testing debug builds to ensure that
+ * they will compile when the build type is switched to RC or STABLE, the
+ * default is just to use PNG_LIBPNG_BUILD_BASE_TYPE.  Set this in CPPFLAGS
+ * with either:
  *
- * By default libpng is built without any internal limits on image size,
- * individual heap (png_malloc) allocations or the total amount of memory used.
- * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
- * (unless individually overridden).  These limits are believed to be fairly
- * safe, but builders of secure systems should verify the values against the
- * real system capabilities.
+ *   -DPNG_RELEASE_BUILD Turns on the release compile path
+ *   -DPNG_RELEASE_BUILD=0 Turns it off
+ * or in your pngusr.h with
+ *   #define PNG_RELEASE_BUILD=1 Turns on the release compile path
+ *   #define PNG_RELEASE_BUILD=0 Turns it off
  */
-#ifdef PNG_SAFE_LIMITS_SUPPORTED
-   /* 'safe' limits */
-#  ifndef PNG_USER_WIDTH_MAX
-#     define PNG_USER_WIDTH_MAX 1000000
-#  endif
-#  ifndef PNG_USER_HEIGHT_MAX
-#     define PNG_USER_HEIGHT_MAX 1000000
-#  endif
-#  ifndef PNG_USER_CHUNK_CACHE_MAX
-#     define PNG_USER_CHUNK_CACHE_MAX 128
-#  endif
-#  ifndef PNG_USER_CHUNK_MALLOC_MAX
-#     define PNG_USER_CHUNK_MALLOC_MAX 8000000
-#  endif
-#else
-   /* values for no limits */
-#  ifndef PNG_USER_WIDTH_MAX
-#     define PNG_USER_WIDTH_MAX 0x7fffffff
-#  endif
-#  ifndef PNG_USER_HEIGHT_MAX
-#     define PNG_USER_HEIGHT_MAX 0x7fffffff
-#  endif
-#  ifndef PNG_USER_CHUNK_CACHE_MAX
-#     define PNG_USER_CHUNK_CACHE_MAX 0
-#  endif
-#  ifndef PNG_USER_CHUNK_MALLOC_MAX
-#     define PNG_USER_CHUNK_MALLOC_MAX 0
-#  endif
+#ifndef PNG_RELEASE_BUILD
+#  define PNG_RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC)
 #endif
 
-/* Moved to pngpriv.h at libpng-1.5.0 */
-/* NOTE: some of these may have been used in external applications as
- * these definitions were exposed in pngconf.h prior to 1.5.
+/* SECURITY and SAFETY:
+ *
+ * libpng is built with support for internal limits on image dimensions and
+ * memory usage.  These are documented in scripts/pnglibconf.dfa of the
+ * source and recorded in the machine generated header file pnglibconf.h.
  */
 
 /* If you are running on a machine where you cannot allocate more
@@ -582,13 +563,13 @@
 #define PNG_RGB_TO_GRAY_WARN  0x400000
 #define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
 #define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
-#define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
-#define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
-#define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
-                       /*   0x8000000 unused */
-                       /*  0x10000000 unused */
-                       /*  0x20000000 unused */
-                       /*  0x40000000 unused */
+#define PNG_ADD_ALPHA        0x1000000 /* Added to libpng-1.2.7 */
+#define PNG_EXPAND_tRNS      0x2000000 /* Added to libpng-1.2.9 */
+#define PNG_SCALE_16_TO_8    0x4000000 /* Added to libpng-1.5.4 */
+                       /*    0x8000000 unused */
+                       /*   0x10000000 unused */
+                       /*   0x20000000 unused */
+                       /*   0x40000000 unused */
 /* Flags for png_create_struct */
 #define PNG_STRUCT_PNG   0x0001
 #define PNG_STRUCT_INFO  0x0002
@@ -780,15 +761,17 @@
  * macro will fail on top-bit-set values because of the sign extension.
  */
 #define PNG_CHUNK_FROM_STRING(s)\
-   PNG_U32(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
+   PNG_U32(0xff & (s)[0], 0xff & (s)[1], 0xff & (s)[2], 0xff & (s)[3])
 
 /* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
  * signed and the argument is a (char[])  This macro will fail miserably on
  * systems where (char) is more than 8 bits.
  */
 #define PNG_STRING_FROM_CHUNK(s,c)\
-   (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
-   ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
+   (void)(((char*)(s))[0]=(char)(((c)>>24) & 0xff), \
+   ((char*)(s))[1]=(char)(((c)>>16) & 0xff),\
+   ((char*)(s))[2]=(char)(((c)>>8) & 0xff), \
+   ((char*)(s))[3]=(char)((c & 0xff)))
 
 /* Do the same but terminate with a null character. */
 #define PNG_CSTRING_FROM_CHUNK(s,c)\
@@ -850,12 +833,13 @@ PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_table, [256]);
 PNG_INTERNAL_DATA(const png_uint_16, png_sRGB_base, [512]);
 PNG_INTERNAL_DATA(const png_byte, png_sRGB_delta, [512]);
 
-#define PNG_sRGB_FROM_LINEAR(linear) ((png_byte)((png_sRGB_base[(linear)>>15] +\
-   ((((linear)&0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8))
+#define PNG_sRGB_FROM_LINEAR(linear) \
+  ((png_byte)(0xff & ((png_sRGB_base[(linear)>>15] \
+   + ((((linear) & 0x7fff)*png_sRGB_delta[(linear)>>15])>>12)) >> 8)))
    /* Given a value 'linear' in the range 0..255*65535 calculate the 8-bit sRGB
     * encoded value with maximum error 0.646365.  Note that the input is not a
     * 16-bit value; it has been multiplied by 255! */
-#endif /* PNG_SIMPLIFIED_READ/WRITE */
+#endif /* SIMPLIFIED_READ/WRITE */
 
 
 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
@@ -910,7 +894,7 @@ PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_base,(png_const_structrp png_ptr,
 #if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
    defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
 /* Internal array allocator, outputs no error or warning messages on failure,
- * just returns NULL.  
+ * just returns NULL.
  */
 PNG_INTERNAL_FUNCTION(png_voidp,png_malloc_array,(png_const_structrp png_ptr,
    int nelements, size_t element_size),PNG_ALLOCATED);
@@ -1090,7 +1074,7 @@ PNG_INTERNAL_FUNCTION(void,png_write_tEXt,(png_structrp png_ptr,
 
 #ifdef PNG_WRITE_zTXt_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_write_zTXt,(png_structrp png_ptr, png_const_charp
-    key, png_const_charp text, png_size_t text_len, int compression),PNG_EMPTY);
+    key, png_const_charp text, int compression),PNG_EMPTY);
 #endif
 
 #ifdef PNG_WRITE_iTXt_SUPPORTED
@@ -1229,7 +1213,7 @@ PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
 PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
    PNG_EMPTY);
    /* Finish a row while reading, dealing with interlacing passes, etc. */
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* SEQUENTIAL_READ */
 
 /* Initialize the row buffers, etc. */
 PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
@@ -1305,7 +1289,7 @@ PNG_INTERNAL_FUNCTION(void,png_handle_hIST,(png_structrp png_ptr,
 #ifdef PNG_READ_iCCP_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_handle_iCCP,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif /* PNG_READ_iCCP_SUPPORTED */
+#endif /* READ_iCCP */
 
 #ifdef PNG_READ_iTXt_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_handle_iTXt,(png_structrp png_ptr,
@@ -1340,7 +1324,7 @@ PNG_INTERNAL_FUNCTION(void,png_handle_sCAL,(png_structrp png_ptr,
 #ifdef PNG_READ_sPLT_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_handle_sPLT,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length),PNG_EMPTY);
-#endif /* PNG_READ_sPLT_SUPPORTED */
+#endif /* READ_sPLT */
 
 #ifdef PNG_READ_sRGB_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_handle_sRGB,(png_structrp png_ptr,
@@ -1454,7 +1438,7 @@ PNG_INTERNAL_FUNCTION(void,png_push_read_iTXt,(png_structrp png_ptr,
     png_inforp info_ptr),PNG_EMPTY);
 #  endif
 
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PROGRESSIVE_READ */
 
 /* Added at libpng version 1.6.0 */
 #ifdef PNG_GAMMA_SUPPORTED

pngread.c

@@ -1,8 +1,8 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.6.11 [June 5, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -44,7 +44,7 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 {
    png_structp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
       error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
-#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* USER_MEM */
 
    if (png_ptr != NULL)
    {
@@ -63,7 +63,7 @@ png_create_read_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
          /* In stable builds only warn if an application error can be completely
           * handled.
           */
-#        if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+#        if PNG_RELEASE_BUILD
             png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
 #        endif
 #     endif
@@ -113,20 +113,20 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr)
        */
       if (chunk_name == png_IDAT)
       {
-         if (!(png_ptr->mode & PNG_HAVE_IHDR))
+         if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
             png_chunk_error(png_ptr, "Missing IHDR before IDAT");
 
          else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-             !(png_ptr->mode & PNG_HAVE_PLTE))
+             (png_ptr->mode & PNG_HAVE_PLTE) == 0)
             png_chunk_error(png_ptr, "Missing PLTE before IDAT");
 
-         else if (png_ptr->mode & PNG_AFTER_IDAT)
+         else if ((png_ptr->mode & PNG_AFTER_IDAT) != 0)
             png_chunk_benign_error(png_ptr, "Too many IDATs found");
 
          png_ptr->mode |= PNG_HAVE_IDAT;
       }
 
-      else if (png_ptr->mode & PNG_HAVE_IDAT)
+      else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
          png_ptr->mode |= PNG_AFTER_IDAT;
 
       /* This should be a binary subdivision search or a hash for
@@ -252,7 +252,7 @@ png_read_info(png_structrp png_ptr, png_inforp info_ptr)
             PNG_HANDLE_CHUNK_AS_DEFAULT);
    }
 }
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* SEQUENTIAL_READ */
 
 /* Optional call to update the users info_ptr structure */
 void PNGAPI
@@ -302,7 +302,7 @@ png_start_read_image(png_structrp png_ptr)
             "png_start_read_image/png_read_update_info: duplicate call");
    }
 }
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* SEQUENTIAL_READ */
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 #ifdef PNG_MNG_FEATURES_SUPPORTED
@@ -315,7 +315,7 @@ png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
    png_debug(1, "in png_do_read_intrapixel");
 
    if (
-       (row_info->color_type & PNG_COLOR_MASK_COLOR))
+       (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       int bytes_per_pixel;
       png_uint_32 row_width = row_info->width;
@@ -369,7 +369,7 @@ png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
       }
    }
 }
-#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* MNG_FEATURES */
 
 void PNGAPI
 png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
@@ -385,7 +385,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
    /* png_read_start_row sets the information (in particular iwidth) for this
     * interlace pass.
     */
-   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+   if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
       png_read_start_row(png_ptr);
 
    /* 1.5.6: row_info moved out of png_struct to a local here. */
@@ -396,45 +396,47 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
    row_info.pixel_depth = png_ptr->pixel_depth;
    row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
 
+#ifdef PNG_WARNINGS_SUPPORTED
    if (png_ptr->row_number == 0 && png_ptr->pass == 0)
    {
    /* Check for transforms that have been set but were defined out */
 #if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
-   if (png_ptr->transformations & PNG_INVERT_MONO)
+   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
       png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined");
 #endif
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
-   if (png_ptr->transformations & PNG_FILLER)
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
       png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined");
 #endif
 
 #if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
     !defined(PNG_READ_PACKSWAP_SUPPORTED)
-   if (png_ptr->transformations & PNG_PACKSWAP)
+   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
       png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined");
 #endif
 
 #if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
-   if (png_ptr->transformations & PNG_PACK)
+   if ((png_ptr->transformations & PNG_PACK) != 0)
       png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined");
 #endif
 
 #if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
-   if (png_ptr->transformations & PNG_SHIFT)
+   if ((png_ptr->transformations & PNG_SHIFT) != 0)
       png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined");
 #endif
 
 #if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
-   if (png_ptr->transformations & PNG_BGR)
+   if ((png_ptr->transformations & PNG_BGR) != 0)
       png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined");
 #endif
 
 #if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
-   if (png_ptr->transformations & PNG_SWAP_BYTES)
+   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
       png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined");
 #endif
    }
+#endif /* WARNINGS */
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* If interlaced and we do not need a new row, combine row and return.
@@ -443,7 +445,8 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
     * untransformed) and, because of the libpng API for interlaced images, this
     * means we must transform before de-interlacing.
     */
-   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+   if (png_ptr->interlaced != 0 &&
+       (png_ptr->transformations & PNG_INTERLACE) != 0)
    {
       switch (png_ptr->pass)
       {
@@ -514,7 +517,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
 
          default:
          case 6:
-            if (!(png_ptr->row_number & 1))
+            if ((png_ptr->row_number & 1) == 0)
             {
                png_read_finish_row(png_ptr);
                return;
@@ -524,7 +527,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
    }
 #endif
 
-   if (!(png_ptr->mode & PNG_HAVE_IDAT))
+   if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
       png_error(png_ptr, "Invalid attempt to read row data");
 
    /* Fill the row with IDAT data: */
@@ -547,7 +550,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
    memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
-   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
        (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */
@@ -573,8 +576,8 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Expand interlaced rows to full size */
-   if (png_ptr->interlaced &&
-      (png_ptr->transformations & PNG_INTERLACE))
+   if (png_ptr->interlaced != 0 &&
+      (png_ptr->transformations & PNG_INTERLACE) != 0)
    {
       if (png_ptr->pass < 6)
          png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
@@ -602,7 +605,7 @@ png_read_row(png_structrp png_ptr, png_bytep row, png_bytep dsp_row)
       (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
 
 }
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* SEQUENTIAL_READ */
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 /* Read one or more rows of image data.  If the image is interlaced,
@@ -669,7 +672,7 @@ png_read_rows(png_structrp png_ptr, png_bytepp row,
          dp++;
       }
 }
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* SEQUENTIAL_READ */
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 /* Read the entire image.  If the image has an alpha channel or a tRNS
@@ -697,7 +700,7 @@ png_read_image(png_structrp png_ptr, png_bytepp image)
       return;
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
-   if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+   if ((png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
    {
       pass = png_set_interlace_handling(png_ptr);
       /* And make sure transforms are initialized. */
@@ -705,7 +708,8 @@ png_read_image(png_structrp png_ptr, png_bytepp image)
    }
    else
    {
-      if (png_ptr->interlaced && !(png_ptr->transformations & PNG_INTERLACE))
+      if (png_ptr->interlaced != 0 &&
+          (png_ptr->transformations & PNG_INTERLACE) == 0)
       {
          /* Caller called png_start_read_image or png_read_update_info without
           * first turning on the PNG_INTERLACE transform.  We can fix this here,
@@ -742,7 +746,7 @@ png_read_image(png_structrp png_ptr, png_bytepp image)
       }
    }
 }
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* SEQUENTIAL_READ */
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
 /* Read the end of the PNG file.  Will not read past the end of the
@@ -765,7 +769,7 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
     * still be pending IDAT data and an owned zstream.  Deal with this here.
     */
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   if (!png_chunk_unknown_handling(png_ptr, png_IDAT))
+   if (png_chunk_unknown_handling(png_ptr, png_IDAT) == 0)
 #endif
       png_read_finish_IDAT(png_ptr);
 
@@ -795,7 +799,8 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
       {
          if (chunk_name == png_IDAT)
          {
-            if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+            if ((length > 0) ||
+                (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
                png_benign_error(png_ptr, "Too many IDATs found");
          }
          png_handle_unknown(png_ptr, info_ptr, length, keep);
@@ -809,7 +814,7 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
          /* Zero length IDATs are legal after the last IDAT has been
           * read, but not after other chunks have been read.
           */
-         if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+         if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT) != 0)
             png_benign_error(png_ptr, "Too many IDATs found");
 
          png_crc_finish(png_ptr, length);
@@ -905,9 +910,9 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
       else
          png_handle_unknown(png_ptr, info_ptr, length,
             PNG_HANDLE_CHUNK_AS_DEFAULT);
-   } while (!(png_ptr->mode & PNG_HAVE_IEND));
+   } while ((png_ptr->mode & PNG_HAVE_IEND) == 0);
 }
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* SEQUENTIAL_READ */
 
 /* Free all memory used in the read struct */
 static void
@@ -920,22 +925,33 @@ png_read_destroy(png_structrp png_ptr)
 #endif
 
    png_free(png_ptr, png_ptr->big_row_buf);
+   png_ptr->big_row_buf = NULL;
    png_free(png_ptr, png_ptr->big_prev_row);
+   png_ptr->big_prev_row = NULL;
    png_free(png_ptr, png_ptr->read_buffer);
+   png_ptr->read_buffer = NULL;
 
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
    png_free(png_ptr, png_ptr->palette_lookup);
+   png_ptr->palette_lookup = NULL;
    png_free(png_ptr, png_ptr->quantize_index);
+   png_ptr->quantize_index = NULL;
 #endif
 
-   if (png_ptr->free_me & PNG_FREE_PLTE)
+   if ((png_ptr->free_me & PNG_FREE_PLTE) != 0)
+   {
       png_zfree(png_ptr, png_ptr->palette);
+      png_ptr->palette = NULL;
+   }
    png_ptr->free_me &= ~PNG_FREE_PLTE;
 
 #if defined(PNG_tRNS_SUPPORTED) || \
     defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   if (png_ptr->free_me & PNG_FREE_TRNS)
+   if ((png_ptr->free_me & PNG_FREE_TRNS) != 0)
+   {
       png_free(png_ptr, png_ptr->trans_alpha);
+      png_ptr->trans_alpha = NULL;
+   }
    png_ptr->free_me &= ~PNG_FREE_TRNS;
 #endif
 
@@ -943,15 +959,18 @@ png_read_destroy(png_structrp png_ptr)
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
    png_free(png_ptr, png_ptr->save_buffer);
+   png_ptr->save_buffer = NULL;
 #endif
 
 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) && \
    defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
    png_free(png_ptr, png_ptr->unknown_chunk.data);
+   png_ptr->unknown_chunk.data = NULL;
 #endif
 
 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
    png_free(png_ptr, png_ptr->chunk_list);
+   png_ptr->chunk_list = NULL;
 #endif
 
    /* NOTE: the 'setjmp' buffer may still be allocated and the memory and error
@@ -1023,7 +1042,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 
    /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
     */
-   if (transforms & PNG_TRANSFORM_SCALE_16)
+   if ((transforms & PNG_TRANSFORM_SCALE_16) != 0)
      /* Added at libpng-1.5.4. "strip_16" produces the same result that it
       * did in earlier versions, while "scale_16" is now more accurate.
       */
@@ -1037,7 +1056,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
     * latter by doing SCALE first.  This is ok and allows apps not to check for
     * which is supported to get the right answer.
     */
-   if (transforms & PNG_TRANSFORM_STRIP_16)
+   if ((transforms & PNG_TRANSFORM_STRIP_16) != 0)
 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
       png_set_strip_16(png_ptr);
 #else
@@ -1047,7 +1066,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
    /* Strip alpha bytes from the input data without combining with
     * the background (not recommended).
     */
-   if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
+   if ((transforms & PNG_TRANSFORM_STRIP_ALPHA) != 0)
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
       png_set_strip_alpha(png_ptr);
 #else
@@ -1057,7 +1076,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
    /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
     * byte into separate bytes (useful for paletted and grayscale images).
     */
-   if (transforms & PNG_TRANSFORM_PACKING)
+   if ((transforms & PNG_TRANSFORM_PACKING) != 0)
 #ifdef PNG_READ_PACK_SUPPORTED
       png_set_packing(png_ptr);
 #else
@@ -1067,7 +1086,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
    /* Change the order of packed pixels to least significant bit first
     * (not useful if you are using png_set_packing).
     */
-   if (transforms & PNG_TRANSFORM_PACKSWAP)
+   if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
 #ifdef PNG_READ_PACKSWAP_SUPPORTED
       png_set_packswap(png_ptr);
 #else
@@ -1079,7 +1098,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
     * Expand paletted or RGB images with transparency to full alpha
     * channels so the data will be available as RGBA quartets.
     */
-   if (transforms & PNG_TRANSFORM_EXPAND)
+   if ((transforms & PNG_TRANSFORM_EXPAND) != 0)
 #ifdef PNG_READ_EXPAND_SUPPORTED
       png_set_expand(png_ptr);
 #else
@@ -1091,7 +1110,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 
    /* Invert monochrome files to have 0 as white and 1 as black
     */
-   if (transforms & PNG_TRANSFORM_INVERT_MONO)
+   if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
 #ifdef PNG_READ_INVERT_SUPPORTED
       png_set_invert_mono(png_ptr);
 #else
@@ -1102,16 +1121,16 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
     * [0,65535] to the original [0,7] or [0,31], or whatever range the
     * colors were originally in:
     */
-   if (transforms & PNG_TRANSFORM_SHIFT)
+   if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
 #ifdef PNG_READ_SHIFT_SUPPORTED
-      if (info_ptr->valid & PNG_INFO_sBIT)
+      if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
          png_set_shift(png_ptr, &info_ptr->sig_bit);
 #else
       png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
 #endif
 
    /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
-   if (transforms & PNG_TRANSFORM_BGR)
+   if ((transforms & PNG_TRANSFORM_BGR) != 0)
 #ifdef PNG_READ_BGR_SUPPORTED
       png_set_bgr(png_ptr);
 #else
@@ -1119,7 +1138,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 #endif
 
    /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
-   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+   if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
       png_set_swap_alpha(png_ptr);
 #else
@@ -1127,7 +1146,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 #endif
 
    /* Swap bytes of 16-bit files to least significant byte first */
-   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+   if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
 #ifdef PNG_READ_SWAP_SUPPORTED
       png_set_swap(png_ptr);
 #else
@@ -1136,7 +1155,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 
 /* Added at libpng-1.2.41 */
    /* Invert the alpha channel from opacity to transparency */
-   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+   if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
       png_set_invert_alpha(png_ptr);
 #else
@@ -1145,7 +1164,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 
 /* Added at libpng-1.2.41 */
    /* Expand grayscale image to RGB */
-   if (transforms & PNG_TRANSFORM_GRAY_TO_RGB)
+   if ((transforms & PNG_TRANSFORM_GRAY_TO_RGB) != 0)
 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
       png_set_gray_to_rgb(png_ptr);
 #else
@@ -1153,7 +1172,7 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 #endif
 
 /* Added at libpng-1.5.4 */
-   if (transforms & PNG_TRANSFORM_EXPAND_16)
+   if ((transforms & PNG_TRANSFORM_EXPAND_16) != 0)
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
       png_set_expand_16(png_ptr);
 #else
@@ -1201,8 +1220,8 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 
    PNG_UNUSED(params)
 }
-#endif /* PNG_INFO_IMAGE_SUPPORTED */
-#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
+#endif /* INFO_IMAGE */
+#endif /* SEQUENTIAL_READ */
 
 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
 /* SIMPLIFIED READ
@@ -1311,10 +1330,10 @@ png_image_format(png_structrp png_ptr)
 {
    png_uint_32 format = 0;
 
-   if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+   if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
       format |= PNG_FORMAT_FLAG_COLOR;
 
-   if (png_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+   if ((png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
       format |= PNG_FORMAT_FLAG_ALPHA;
 
    /* Use png_ptr here, not info_ptr, because by examination png_handle_tRNS
@@ -1328,7 +1347,7 @@ png_image_format(png_structrp png_ptr)
    if (png_ptr->bit_depth == 16)
       format |= PNG_FORMAT_FLAG_LINEAR;
 
-   if (png_ptr->color_type & PNG_COLOR_MASK_PALETTE)
+   if ((png_ptr->color_type & PNG_COLOR_MASK_PALETTE) != 0)
       format |= PNG_FORMAT_FLAG_COLORMAP;
 
    return format;
@@ -1428,7 +1447,7 @@ png_image_begin_read_from_stdio(png_imagep image, FILE* file)
    {
       if (file != NULL)
       {
-         if (png_image_read_init(image))
+         if (png_image_read_init(image) != 0)
          {
             /* This is slightly evil, but png_init_io doesn't do anything other
              * than this and we haven't changed the standard IO functions so
@@ -1462,7 +1481,7 @@ png_image_begin_read_from_file(png_imagep image, const char *file_name)
 
          if (fp != NULL)
          {
-            if (png_image_read_init(image))
+            if (png_image_read_init(image) != 0)
             {
                image->opaque->png_ptr->io_ptr = fp;
                image->opaque->owned_file = 1;
@@ -1488,7 +1507,7 @@ png_image_begin_read_from_file(png_imagep image, const char *file_name)
 
    return 0;
 }
-#endif /* PNG_STDIO_SUPPORTED */
+#endif /* STDIO */
 
 static void PNGCBAPI
 png_image_memory_read(png_structp png_ptr, png_bytep out, png_size_t need)
@@ -1527,7 +1546,7 @@ int PNGAPI png_image_begin_read_from_memory(png_imagep image,
    {
       if (memory != NULL && size > 0)
       {
-         if (png_image_read_init(image))
+         if (png_image_read_init(image) != 0)
          {
             /* Now set the IO functions to read from the memory buffer and
              * store it into io_ptr.  Again do this in-place to avoid calling a
@@ -1599,14 +1618,14 @@ png_image_skip_unused_chunks(png_structrp png_ptr)
 
        /* But do not ignore image data handling chunks */
        png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_AS_DEFAULT,
-         chunks_to_process, (sizeof chunks_to_process)/5);
+         chunks_to_process, (int)/*SAFE*/(sizeof chunks_to_process)/5);
     }
 }
 
 #  define PNG_SKIP_CHUNKS(p) png_image_skip_unused_chunks(p)
 #else
 #  define PNG_SKIP_CHUNKS(p) ((void)0)
-#endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
+#endif /* HANDLE_AS_UNKNOWN */
 
 /* The following macro gives the exact rounded answer for all values in the
  * range 0..255 (it actually divides by 51.2, but the rounding still generates
@@ -1619,9 +1638,9 @@ static void
 set_file_encoding(png_image_read_control *display)
 {
    png_fixed_point g = display->image->opaque->png_ptr->colorspace.gamma;
-   if (png_gamma_significant(g))
+   if (png_gamma_significant(g) != 0)
    {
-      if (png_gamma_not_sRGB(g))
+      if (png_gamma_not_sRGB(g) != 0)
       {
          display->file_encoding = P_FILE;
          display->gamma_to_linear = png_reciprocal(g);
@@ -1716,7 +1735,7 @@ png_create_colormap_entry(png_image_read_control *display,
    png_uint_32 alpha, int encoding)
 {
    png_imagep image = display->image;
-   const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) ?
+   const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
       P_LINEAR : P_sRGB;
    const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 &&
       (red != green || green != blue);
@@ -1746,7 +1765,7 @@ png_create_colormap_entry(png_image_read_control *display,
       green = png_gamma_16bit_correct(green*257, g);
       blue = png_gamma_16bit_correct(blue*257, g);
 
-      if (convert_to_Y || output_encoding == P_LINEAR)
+      if (convert_to_Y != 0 || output_encoding == P_LINEAR)
       {
          alpha *= 257;
          encoding = P_LINEAR;
@@ -1773,7 +1792,8 @@ png_create_colormap_entry(png_image_read_control *display,
       encoding = P_LINEAR;
    }
 
-   else if (encoding == P_sRGB && (convert_to_Y || output_encoding == P_LINEAR))
+   else if (encoding == P_sRGB &&
+       (convert_to_Y  != 0 || output_encoding == P_LINEAR))
    {
       /* The values are 8-bit sRGB values, but must be converted to 16-bit
        * linear.
@@ -1803,6 +1823,7 @@ png_create_colormap_entry(png_image_read_control *display,
             y = (y + 128) >> 8;
             y *= 255;
             y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7);
+            alpha = PNG_DIV257(alpha);
             encoding = P_sRGB;
          }
 
@@ -1831,7 +1852,7 @@ png_create_colormap_entry(png_image_read_control *display,
 #        define afirst 0
 #     endif
 #     ifdef PNG_FORMAT_BGR_SUPPORTED
-         const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) ? 2 : 0;
+         const int bgr = (image->format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
 #     else
 #        define bgr 0
 #     endif
@@ -2043,7 +2064,7 @@ png_image_read_colormap(png_voidp argument)
 
    const png_structrp png_ptr = image->opaque->png_ptr;
    const png_uint_32 output_format = image->format;
-   const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) ?
+   const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) != 0 ?
       P_LINEAR : P_sRGB;
 
    unsigned int cmap_entries;
@@ -2082,7 +2103,7 @@ png_image_read_colormap(png_voidp argument)
       else
       {
          back_g = display->background->green;
-         if (output_format & PNG_FORMAT_FLAG_COLOR)
+         if ((output_format & PNG_FORMAT_FLAG_COLOR) != 0)
          {
             back_r = display->background->red;
             back_b = display->background->blue;
@@ -2224,7 +2245,7 @@ png_image_read_colormap(png_voidp argument)
             {
                unsigned int back_alpha;
 
-               if (output_format & PNG_FORMAT_FLAG_ALPHA)
+               if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
                   back_alpha = 0;
 
                else
@@ -2265,8 +2286,14 @@ png_image_read_colormap(png_voidp argument)
                      output_processing = PNG_CMAP_NONE;
                      break;
                   }
-
+#ifdef __COVERITY__
+                 /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+                  * here.
+                  */
+                  back_alpha = 255;
+#else
                   back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
+#endif
                }
 
                /* output_processing means that the libpng-processed row will be
@@ -2305,7 +2332,7 @@ png_image_read_colormap(png_voidp argument)
           */
          data_encoding = P_sRGB;
 
-         if (output_format & PNG_FORMAT_FLAG_ALPHA)
+         if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
          {
             if (PNG_GA_COLORMAP_ENTRIES > image->colormap_entries)
                png_error(png_ptr, "gray+alpha color-map: too few entries");
@@ -2391,7 +2418,14 @@ png_image_read_colormap(png_voidp argument)
                 */
                background_index = i;
                png_create_colormap_entry(display, i++, back_r, back_g, back_b,
-                  output_encoding == P_LINEAR ? 65535U : 255U, output_encoding);
+#ifdef __COVERITY__
+                 /* Coverity claims that output_encoding cannot be 2 (P_LINEAR)
+                  * here.
+                  */ 255U,
+#else
+                  output_encoding == P_LINEAR ? 65535U : 255U,
+#endif
+                  output_encoding);
 
                /* For non-opaque input composite on the sRGB background - this
                 * requires inverting the encoding for each component.  The input
@@ -2500,7 +2534,7 @@ png_image_read_colormap(png_voidp argument)
                 */
                if ((png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
                   png_ptr->num_trans > 0) &&
-                  png_gamma_not_sRGB(png_ptr->colorspace.gamma))
+                  png_gamma_not_sRGB(png_ptr->colorspace.gamma) != 0)
                {
                   cmap_entries = make_gray_file_colormap(display);
                   data_encoding = P_FILE;
@@ -2588,7 +2622,7 @@ png_image_read_colormap(png_voidp argument)
                /* Is there alpha in the output too?  If so all four channels are
                 * processed into a special RGB cube with alpha support.
                 */
-               if (output_format & PNG_FORMAT_FLAG_ALPHA)
+               if ((output_format & PNG_FORMAT_FLAG_ALPHA) != 0)
                {
                   png_uint_32 r;
 
@@ -2762,7 +2796,7 @@ png_image_read_colormap(png_voidp argument)
 
             for (i=0; i < cmap_entries; ++i)
             {
-               if (do_background && i < num_trans && trans[i] < 255)
+               if (do_background != 0 && i < num_trans && trans[i] < 255)
                {
                   if (trans[i] == 0)
                      png_create_colormap_entry(display, i, back_r, back_g,
@@ -2807,8 +2841,8 @@ png_image_read_colormap(png_voidp argument)
    }
 
    /* Now deal with the output processing */
-   if (expand_tRNS && png_ptr->num_trans > 0 &&
-      (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0)
+   if (expand_tRNS != 0 && png_ptr->num_trans > 0 &&
+       (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) == 0)
       png_set_tRNS_to_alpha(png_ptr);
 
    switch (data_encoding)
@@ -3224,7 +3258,8 @@ png_image_read_composite(png_voidp argument)
       png_uint_32  height = image->height;
       png_uint_32  width = image->width;
       ptrdiff_t    step_row = display->row_bytes;
-      unsigned int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
+      unsigned int channels =
+          (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
       int pass;
 
       for (pass = 0; pass < passes; ++pass)
@@ -3522,7 +3557,8 @@ png_image_read_background(png_voidp argument)
             int swap_alpha = 0;
 
 #           ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
-               if (preserve_alpha && (image->format & PNG_FORMAT_FLAG_AFIRST))
+               if (preserve_alpha != 0 &&
+                   (image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
                   swap_alpha = 1;
 #           endif
 
@@ -3631,10 +3667,10 @@ png_image_read_direct(png_voidp argument)
       int mode; /* alpha mode */
 
       /* Do this first so that we have a record if rgb to gray is happening. */
-      if (change & PNG_FORMAT_FLAG_COLOR)
+      if ((change & PNG_FORMAT_FLAG_COLOR) != 0)
       {
          /* gray<->color transformation required. */
-         if (format & PNG_FORMAT_FLAG_COLOR)
+         if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
             png_set_gray_to_rgb(png_ptr);
 
          else
@@ -3652,7 +3688,7 @@ png_image_read_direct(png_voidp argument)
              * enormous change) 'do_local_background' is used to indicate that
              * the problem exists.
              */
-            if (base_format & PNG_FORMAT_FLAG_ALPHA)
+            if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
                do_local_background = 1/*maybe*/;
 
             png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE,
@@ -3667,8 +3703,8 @@ png_image_read_direct(png_voidp argument)
       {
          png_fixed_point input_gamma_default;
 
-         if ((base_format & PNG_FORMAT_FLAG_LINEAR) &&
-            (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
+         if ((base_format & PNG_FORMAT_FLAG_LINEAR) != 0 &&
+             (image->flags & PNG_IMAGE_FLAG_16BIT_sRGB) == 0)
             input_gamma_default = PNG_GAMMA_LINEAR;
          else
             input_gamma_default = PNG_DEFAULT_sRGB;
@@ -3684,7 +3720,7 @@ png_image_read_direct(png_voidp argument)
          /* If there *is* an alpha channel in the input it must be multiplied
           * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG.
           */
-         if (base_format & PNG_FORMAT_FLAG_ALPHA)
+         if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
             mode = PNG_ALPHA_STANDARD; /* associated alpha */
 
          else
@@ -3715,7 +3751,7 @@ png_image_read_direct(png_voidp argument)
           * final value.
           */
          if (png_muldiv(&gtest, output_gamma, png_ptr->colorspace.gamma,
-               PNG_FP_1) && !png_gamma_significant(gtest))
+               PNG_FP_1) != 0 && png_gamma_significant(gtest) == 0)
             do_local_background = 0;
 
          else if (mode == PNG_ALPHA_STANDARD)
@@ -3728,9 +3764,9 @@ png_image_read_direct(png_voidp argument)
       }
 
       /* If the bit-depth changes then handle that here. */
-      if (change & PNG_FORMAT_FLAG_LINEAR)
+      if ((change & PNG_FORMAT_FLAG_LINEAR) != 0)
       {
-         if (linear /*16-bit output*/)
+         if (linear != 0 /*16-bit output*/)
             png_set_expand_16(png_ptr);
 
          else /* 8-bit output */
@@ -3740,13 +3776,13 @@ png_image_read_direct(png_voidp argument)
       }
 
       /* Now the background/alpha channel changes. */
-      if (change & PNG_FORMAT_FLAG_ALPHA)
+      if ((change & PNG_FORMAT_FLAG_ALPHA) != 0)
       {
          /* Removing an alpha channel requires composition for the 8-bit
           * formats; for the 16-bit it is already done, above, by the
           * pre-multiplication and the channel just needs to be stripped.
           */
-         if (base_format & PNG_FORMAT_FLAG_ALPHA)
+         if ((base_format & PNG_FORMAT_FLAG_ALPHA) != 0)
          {
             /* If RGB->gray is happening the alpha channel must be left and the
              * operation completed locally.
@@ -3811,7 +3847,7 @@ png_image_read_direct(png_voidp argument)
                filler = 255;
 
 #           ifdef PNG_FORMAT_AFIRST_SUPPORTED
-               if (format & PNG_FORMAT_FLAG_AFIRST)
+               if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
                {
                   where = PNG_FILLER_BEFORE;
                   change &= ~PNG_FORMAT_FLAG_AFIRST;
@@ -3835,12 +3871,12 @@ png_image_read_direct(png_voidp argument)
       png_set_alpha_mode_fixed(png_ptr, mode, output_gamma);
 
 #     ifdef PNG_FORMAT_BGR_SUPPORTED
-         if (change & PNG_FORMAT_FLAG_BGR)
+         if ((change & PNG_FORMAT_FLAG_BGR) != 0)
          {
             /* Check only the output format; PNG is never BGR; don't do this if
              * the output is gray, but fix up the 'format' value in that case.
              */
-            if (format & PNG_FORMAT_FLAG_COLOR)
+            if ((format & PNG_FORMAT_FLAG_COLOR) != 0)
                png_set_bgr(png_ptr);
 
             else
@@ -3851,14 +3887,14 @@ png_image_read_direct(png_voidp argument)
 #     endif
 
 #     ifdef PNG_FORMAT_AFIRST_SUPPORTED
-         if (change & PNG_FORMAT_FLAG_AFIRST)
+         if ((change & PNG_FORMAT_FLAG_AFIRST) != 0)
          {
             /* Only relevant if there is an alpha channel - it's particularly
              * important to handle this correctly because do_local_compose may
              * be set above and then libpng will keep the alpha channel for this
              * code to remove.
              */
-            if (format & PNG_FORMAT_FLAG_ALPHA)
+            if ((format & PNG_FORMAT_FLAG_ALPHA) != 0)
             {
                /* Disable this if doing a local background,
                 * TODO: remove this when local background is no longer required.
@@ -3881,7 +3917,7 @@ png_image_read_direct(png_voidp argument)
       {
          PNG_CONST png_uint_16 le = 0x0001;
 
-         if (*(png_const_bytep)&le)
+         if ((*(png_const_bytep) & le) != 0)
             png_set_swap(png_ptr);
       }
 
@@ -3906,10 +3942,10 @@ png_image_read_direct(png_voidp argument)
    {
       png_uint_32 info_format = 0;
 
-      if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+      if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
          info_format |= PNG_FORMAT_FLAG_COLOR;
 
-      if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+      if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
       {
          /* do_local_compose removes this channel below. */
          if (do_local_compose == 0)
@@ -3928,14 +3964,14 @@ png_image_read_direct(png_voidp argument)
          info_format |= PNG_FORMAT_FLAG_LINEAR;
 
 #     ifdef PNG_FORMAT_BGR_SUPPORTED
-         if (png_ptr->transformations & PNG_BGR)
+         if ((png_ptr->transformations & PNG_BGR) != 0)
             info_format |= PNG_FORMAT_FLAG_BGR;
 #     endif
 
 #     ifdef PNG_FORMAT_AFIRST_SUPPORTED
          if (do_local_background == 2)
          {
-            if (format & PNG_FORMAT_FLAG_AFIRST)
+            if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
                info_format |= PNG_FORMAT_FLAG_AFIRST;
          }
 
@@ -4064,7 +4100,7 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
             /* Choose the correct 'end' routine; for the color-map case all the
              * setup has already been done.
              */
-            if (image->format & PNG_FORMAT_FLAG_COLORMAP)
+            if ((image->format & PNG_FORMAT_FLAG_COLORMAP) != 0)
                result =
                   png_safe_execute(image, png_image_read_colormap, &display) &&
                   png_safe_execute(image, png_image_read_colormapped, &display);
@@ -4094,5 +4130,5 @@ png_image_finish_read(png_imagep image, png_const_colorp background,
    return 0;
 }
 
-#endif /* PNG_SIMPLIFIED_READ_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED */
+#endif /* SIMPLIFIED_READ */
+#endif /* READ */

pngrio.c

@@ -1,8 +1,8 @@
 
 /* pngrio.c - functions for data input
  *
- * Last changed in libpng 1.6.9 [February 6, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -26,7 +26,7 @@
  * reads from a file pointer.  Note that this routine sometimes gets called
  * with very small lengths, so you should implement some kind of simple
  * buffering if you are using unbuffered reads.  This should never be asked
- * to read more then 64K on a 16 bit machine.
+ * to read more than 64K on a 16 bit machine.
  */
 void /* PRIVATE */
 png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length)
@@ -117,4 +117,4 @@ png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
    png_ptr->output_flush_fn = NULL;
 #endif
 }
-#endif /* PNG_READ_SUPPORTED */
+#endif /* READ */

pngset.c

@@ -1,8 +1,8 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.6.11 [June 5, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -59,7 +59,7 @@ png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
    xy.whitey = white_y;
 
    if (png_colorspace_set_chromaticities(png_ptr, &info_ptr->colorspace, &xy,
-      2/* override with app values*/))
+       2/* override with app values*/) != 0)
       info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
 
    png_colorspace_sync_info(png_ptr, info_ptr);
@@ -90,7 +90,8 @@ png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr,
    XYZ.blue_Y = int_blue_Y;
    XYZ.blue_Z = int_blue_Z;
 
-   if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace, &XYZ, 2))
+   if (png_colorspace_set_endpoints(png_ptr, &info_ptr->colorspace,
+       &XYZ, 2) != 0)
       info_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
 
    png_colorspace_sync_info(png_ptr, info_ptr);
@@ -129,9 +130,9 @@ png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X,
       png_fixed(png_ptr, blue_Y, "cHRM Red Y"),
       png_fixed(png_ptr, blue_Z, "cHRM Red Z"));
 }
-#  endif /* PNG_FLOATING_POINT_SUPPORTED */
+#  endif /* FLOATING_POINT */
 
-#endif /* PNG_cHRM_SUPPORTED */
+#endif /* cHRM */
 
 #ifdef PNG_gAMA_SUPPORTED
 void PNGFAPI
@@ -189,6 +190,7 @@ png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
    if (info_ptr->hist == NULL)
    {
       png_warning(png_ptr, "Insufficient memory for hIST chunk data");
+
       return;
    }
 
@@ -227,13 +229,13 @@ png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
    if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       info_ptr->channels = 1;
 
-   else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+   else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
       info_ptr->channels = 3;
 
    else
       info_ptr->channels = 1;
 
-   if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+   if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
       info_ptr->channels++;
 
    info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
@@ -270,7 +272,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
    png_debug1(1, "in %s storage function", "pCAL");
 
    if (png_ptr == NULL || info_ptr == NULL || purpose == NULL || units == NULL
-      || (nparams > 0 && params == NULL))
+       || (nparams > 0 && params == NULL))
       return;
 
    length = strlen(purpose) + 1;
@@ -288,16 +290,19 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
 
    /* Validate params[nparams] */
    for (i=0; i<nparams; ++i)
+   {
       if (params[i] == NULL ||
-         !png_check_fp_string(params[i], strlen(params[i])))
+          !png_check_fp_string(params[i], strlen(params[i])))
          png_error(png_ptr, "Invalid format for pCAL parameter");
+   }
 
    info_ptr->pcal_purpose = png_voidcast(png_charp,
-      png_malloc_warn(png_ptr, length));
+       png_malloc_warn(png_ptr, length));
 
    if (info_ptr->pcal_purpose == NULL)
    {
       png_warning(png_ptr, "Insufficient memory for pCAL purpose");
+
       return;
    }
 
@@ -319,6 +324,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
    if (info_ptr->pcal_units == NULL)
    {
       png_warning(png_ptr, "Insufficient memory for pCAL units");
+
       return;
    }
 
@@ -330,6 +336,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
    if (info_ptr->pcal_params == NULL)
    {
       png_warning(png_ptr, "Insufficient memory for pCAL params");
+
       return;
    }
 
@@ -346,6 +353,7 @@ png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
       if (info_ptr->pcal_params[i] == NULL)
       {
          png_warning(png_ptr, "Insufficient memory for pCAL parameter");
+
          return;
       }
 
@@ -395,6 +403,7 @@ png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
    if (info_ptr->scal_s_width == NULL)
    {
       png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+
       return;
    }
 
@@ -413,6 +422,7 @@ png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr,
       info_ptr->scal_s_width = NULL;
 
       png_warning(png_ptr, "Memory allocation failed while processing sCAL");
+
       return;
    }
 
@@ -516,6 +526,7 @@ png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
       else
       {
          png_warning(png_ptr, "Invalid palette length");
+
          return;
       }
    }
@@ -528,7 +539,6 @@ png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
       ))
    {
       png_error(png_ptr, "Invalid palette");
-      return;
    }
 
    /* It may not actually be necessary to set png_ptr->palette here;
@@ -594,7 +604,8 @@ png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr,
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace, srgb_intent))
+   if (png_colorspace_set_sRGB(png_ptr, &info_ptr->colorspace,
+       srgb_intent) != 0)
    {
       /* This causes the gAMA and cHRM to be written too */
       info_ptr->colorspace.flags |=
@@ -651,6 +662,7 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
    if (new_iccp_name == NULL)
    {
       png_benign_error(png_ptr, "Insufficient memory to process iCCP chunk");
+
       return;
    }
 
@@ -663,6 +675,7 @@ png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
       png_free(png_ptr, new_iccp_name);
       png_benign_error(png_ptr,
           "Insufficient memory to process iCCP profile");
+
       return;
    }
 
@@ -696,7 +709,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    int i;
 
-   png_debug1(1, "in %lx storage function", png_ptr == NULL ? "unexpected" :
+   png_debug1(1, "in %lx storage function", png_ptr == NULL ? 0xabadca11 :
       (unsigned long)png_ptr->chunk_name);
 
    if (png_ptr == NULL || info_ptr == NULL || num_text <= 0 || text_ptr == NULL)
@@ -726,7 +739,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
          else
             max_text = INT_MAX;
 
-         /* Now allocate a new array and copy the old members in, this does all
+         /* Now allocate a new array and copy the old members in; this does all
           * the overflow checks.
           */
          new_text = png_voidcast(png_textp,png_realloc_array(png_ptr,
@@ -738,6 +751,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
       {
          png_chunk_report(png_ptr, "too many text chunks",
             PNG_CHUNK_WRITE_ERROR);
+
          return 1;
       }
 
@@ -793,7 +807,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
          else
             lang_key_len = 0;
       }
-#  else /* PNG_iTXt_SUPPORTED */
+#  else /* iTXt */
       {
          png_chunk_report(png_ptr, "iTXt chunk not supported",
             PNG_CHUNK_WRITE_ERROR);
@@ -826,6 +840,7 @@ png_set_text_2(png_const_structrp png_ptr, png_inforp info_ptr,
       {
          png_chunk_report(png_ptr, "text chunk: out of memory",
                PNG_CHUNK_WRITE_ERROR);
+
          return 1;
       }
 
@@ -890,7 +905,7 @@ png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
    png_debug1(1, "in %s storage function", "tIME");
 
    if (png_ptr == NULL || info_ptr == NULL || mod_time == NULL ||
-       (png_ptr->mode & PNG_WROTE_tIME))
+       (png_ptr->mode & PNG_WROTE_tIME) != 0)
       return;
 
    if (mod_time->month == 0   || mod_time->month > 12  ||
@@ -899,6 +914,7 @@ png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
        mod_time->second > 60)
    {
       png_warning(png_ptr, "Ignoring invalid time value");
+
       return;
    }
 
@@ -915,6 +931,7 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
    png_debug1(1, "in %s storage function", "tRNS");
 
    if (png_ptr == NULL || info_ptr == NULL)
+
       return;
 
    if (trans_alpha != NULL)
@@ -940,16 +957,21 @@ png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr,
 
    if (trans_color != NULL)
    {
-      int sample_max = (1 << info_ptr->bit_depth);
+#ifdef PNG_WARNINGS_SUPPORTED
+      if (info_ptr->bit_depth < 16)
+      {
+         int sample_max = (1 << info_ptr->bit_depth) - 1;
 
-      if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
-          trans_color->gray > sample_max) ||
-          (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
-          (trans_color->red > sample_max ||
-          trans_color->green > sample_max ||
-          trans_color->blue > sample_max)))
-         png_warning(png_ptr,
-            "tRNS chunk has out-of-range samples for bit_depth");
+         if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
+             trans_color->gray > sample_max) ||
+             (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+             (trans_color->red > sample_max ||
+             trans_color->green > sample_max ||
+             trans_color->blue > sample_max)))
+            png_warning(png_ptr,
+               "tRNS chunk has out-of-range samples for bit_depth");
+      }
+#endif
 
       info_ptr->trans_color = *trans_color;
 
@@ -996,6 +1018,7 @@ png_set_sPLT(png_const_structrp png_ptr,
    {
       /* Out of memory or too many chunks */
       png_chunk_report(png_ptr, "too many sPLT chunks", PNG_CHUNK_WRITE_ERROR);
+
       return;
    }
 
@@ -1020,8 +1043,8 @@ png_set_sPLT(png_const_structrp png_ptr,
 
       np->depth = entries->depth;
 
-      /* In the even of out-of-memory just return - there's no point keeping on
-       * trying to add sPLT chunks.
+      /* In the event of out-of-memory just return - there's no point keeping
+       * on trying to add sPLT chunks.
        */
       length = strlen(entries->name) + 1;
       np->name = png_voidcast(png_charp, png_malloc_base(png_ptr, length));
@@ -1032,8 +1055,8 @@ png_set_sPLT(png_const_structrp png_ptr,
       memcpy(np->name, entries->name, length);
 
       /* IMPORTANT: we have memory now that won't get freed if something else
-       * goes wrong, this code must free it.  png_malloc_array produces no
-       * warnings, use a png_chunk_report (below) if there is an error.
+       * goes wrong; this code must free it.  png_malloc_array produces no
+       * warnings; use a png_chunk_report (below) if there is an error.
        */
       np->entries = png_voidcast(png_sPLT_entryp, png_malloc_array(png_ptr,
           entries->nentries, sizeof (png_sPLT_entry)));
@@ -1041,6 +1064,7 @@ png_set_sPLT(png_const_structrp png_ptr,
       if (np->entries == NULL)
       {
          png_free(png_ptr, np->name);
+         np->name = NULL;
          break;
       }
 
@@ -1063,7 +1087,7 @@ png_set_sPLT(png_const_structrp png_ptr,
    if (nentries > 0)
       png_chunk_report(png_ptr, "sPLT out of memory", PNG_CHUNK_WRITE_ERROR);
 }
-#endif /* PNG_sPLT_SUPPORTED */
+#endif /* sPLT */
 
 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 static png_byte
@@ -1072,10 +1096,10 @@ check_location(png_const_structrp png_ptr, int location)
    location &= (PNG_HAVE_IHDR|PNG_HAVE_PLTE|PNG_AFTER_IDAT);
 
    /* New in 1.6.0; copy the location and check it.  This is an API
-    * change, previously the app had to use the
+    * change; previously the app had to use the
     * png_set_unknown_chunk_location API below for each chunk.
     */
-   if (location == 0 && !(png_ptr->mode & PNG_IS_READ_STRUCT))
+   if (location == 0 && (png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
    {
       /* Write struct, so unknown chunks come from the app */
       png_app_warning(png_ptr,
@@ -1110,7 +1134,7 @@ png_set_unknown_chunks(png_const_structrp png_ptr,
    png_unknown_chunkp np;
 
    if (png_ptr == NULL || info_ptr == NULL || num_unknowns <= 0 ||
-      unknowns == NULL)
+       unknowns == NULL)
       return;
 
    /* Check for the failure cases where support has been disabled at compile
@@ -1121,17 +1145,19 @@ png_set_unknown_chunks(png_const_structrp png_ptr,
     */
 #  if !defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) && \
       defined(PNG_READ_SUPPORTED)
-      if (png_ptr->mode & PNG_IS_READ_STRUCT)
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
       {
          png_app_error(png_ptr, "no unknown chunk support on read");
+
          return;
       }
 #  endif
 #  if !defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) && \
       defined(PNG_WRITE_SUPPORTED)
-      if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
       {
          png_app_error(png_ptr, "no unknown chunk support on write");
+
          return;
       }
 #  endif
@@ -1149,6 +1175,7 @@ png_set_unknown_chunks(png_const_structrp png_ptr,
    {
       png_chunk_report(png_ptr, "too many unknown chunks",
          PNG_CHUNK_WRITE_ERROR);
+
       return;
    }
 
@@ -1215,7 +1242,7 @@ png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
       {
          png_app_error(png_ptr, "invalid unknown chunk location");
          /* Fake out the pre 1.6.0 behavior: */
-         if ((location & PNG_HAVE_IDAT)) /* undocumented! */
+         if ((location & PNG_HAVE_IDAT) != 0) /* undocumented! */
             location = PNG_AFTER_IDAT;
 
          else
@@ -1226,8 +1253,7 @@ png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
          check_location(png_ptr, location);
    }
 }
-#endif
-
+#endif /* STORE_UNKNOWN_CHUNKS */
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
 png_uint_32 PNGAPI
@@ -1253,10 +1279,14 @@ add_one_chunk(png_bytep list, unsigned int count, png_const_bytep add, int keep)
    /* Utility function: update the 'keep' state of a chunk if it is already in
     * the list, otherwise add it to the list.
     */
-   for (i=0; i<count; ++i, list += 5) if (memcmp(list, add, 4) == 0)
+   for (i=0; i<count; ++i, list += 5)
    {
-      list[4] = (png_byte)keep;
-      return count;
+      if (memcmp(list, add, 4) == 0)
+      {
+         list[4] = (png_byte)keep;
+
+         return count;
+      }
    }
 
    if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
@@ -1282,6 +1312,7 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
    if (keep < 0 || keep >= PNG_HANDLE_CHUNK_LAST)
    {
       png_app_error(png_ptr, "png_set_keep_unknown_chunks: invalid keep");
+
       return;
    }
 
@@ -1320,7 +1351,7 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
       };
 
       chunk_list = chunks_to_ignore;
-      num_chunks = (sizeof chunks_to_ignore)/5;
+      num_chunks = (unsigned int)/*SAFE*/(sizeof chunks_to_ignore)/5U;
    }
 
    else /* num_chunks_in > 0 */
@@ -1331,6 +1362,7 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
           * which can be switched off.
           */
          png_app_error(png_ptr, "png_set_keep_unknown_chunks: no chunk list");
+
          return;
       }
 
@@ -1346,6 +1378,7 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
    if (num_chunks + old_num_chunks > UINT_MAX/5)
    {
       png_app_error(png_ptr, "png_set_keep_unknown_chunks: too many chunks");
+
       return;
    }
 
@@ -1380,12 +1413,15 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
       unsigned int i;
 
       for (i=0; i<num_chunks; ++i)
+      {
          old_num_chunks = add_one_chunk(new_list, old_num_chunks,
             chunk_list+5*i, keep);
+      }
 
       /* Now remove any spurious 'default' entries. */
       num_chunks = 0;
       for (i=0, inlist=outlist=new_list; i<old_num_chunks; ++i, inlist += 5)
+      {
          if (inlist[4])
          {
             if (outlist != inlist)
@@ -1393,6 +1429,7 @@ png_set_keep_unknown_chunks(png_structrp png_ptr, int keep,
             outlist += 5;
             ++num_chunks;
          }
+      }
 
       /* This means the application has removed all the specialized handling. */
       if (num_chunks == 0)
@@ -1444,7 +1481,8 @@ png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr,
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   if (info_ptr->row_pointers && (info_ptr->row_pointers != row_pointers))
+   if (info_ptr->row_pointers != NULL &&
+       (info_ptr->row_pointers != row_pointers))
       png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
 
    info_ptr->row_pointers = row_pointers;
@@ -1464,7 +1502,7 @@ png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
        png_error(png_ptr, "invalid compression buffer size");
 
 #  ifdef PNG_SEQUENTIAL_READ_SUPPORTED
-      if (png_ptr->mode & PNG_IS_READ_STRUCT)
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
       {
          png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
          return;
@@ -1472,29 +1510,36 @@ png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
 #  endif
 
 #  ifdef PNG_WRITE_SUPPORTED
-      if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
       {
          if (png_ptr->zowner != 0)
          {
             png_warning(png_ptr,
               "Compression buffer size cannot be changed because it is in use");
+
             return;
          }
 
+#ifndef __COVERITY__
+         /* Some compilers complain that this is always false.  However, it
+          * can be true when integer overflow happens.
+          */
          if (size > ZLIB_IO_MAX)
          {
             png_warning(png_ptr,
                "Compression buffer size limited to system maximum");
             size = ZLIB_IO_MAX; /* must fit */
          }
+#endif
 
-         else if (size < 6)
+         if (size < 6)
          {
             /* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
              * if this is permitted.
              */
             png_warning(png_ptr,
                "Compression buffer size cannot be reduced below 6");
+
             return;
          }
 
@@ -1510,7 +1555,7 @@ png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
 void PNGAPI
 png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
 {
-   if (png_ptr && info_ptr)
+   if (png_ptr != NULL && info_ptr != NULL)
       info_ptr->valid &= ~mask;
 }
 
@@ -1536,8 +1581,8 @@ png_set_user_limits (png_structrp png_ptr, png_uint_32 user_width_max,
 void PNGAPI
 png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
 {
-    if (png_ptr != NULL)
-       png_ptr->user_chunk_cache_max = user_chunk_cache_max;
+   if (png_ptr != NULL)
+      png_ptr->user_chunk_cache_max = user_chunk_cache_max;
 }
 
 /* This function was added to libpng 1.4.1 */
@@ -1548,7 +1593,7 @@ png_set_chunk_malloc_max (png_structrp png_ptr,
    if (png_ptr != NULL)
       png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
 }
-#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+#endif /* ?SET_USER_LIMITS */
 
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
@@ -1571,14 +1616,14 @@ png_set_benign_errors(png_structrp png_ptr, int allowed)
       png_ptr->flags &= ~(PNG_FLAG_BENIGN_ERRORS_WARN |
          PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN);
 }
-#endif /* PNG_BENIGN_ERRORS_SUPPORTED */
+#endif /* BENIGN_ERRORS */
 
 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
    /* Whether to report invalid palette index; added at libng-1.5.10.
     * It is possible for an indexed (color-type==3) PNG file to contain
     * pixels with invalid (out-of-range) indexes if the PLTE chunk has
     * fewer entries than the image's bit-depth would allow. We recover
-    * from this gracefully by filling any incomplete palette with zeroes
+    * from this gracefully by filling any incomplete palette with zeros
     * (opaque black).  By default, when this occurs libpng will issue
     * a benign error.  This API can be used to override that behavior.
     */
@@ -1594,4 +1639,4 @@ png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
       png_ptr->num_palette_max = -1;
 }
 #endif
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+#endif /* READ || WRITE */

pngstruct.h

@@ -1,12 +1,11 @@
 
 /* pngstruct.h - header file for PNG reference library
  *
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -101,7 +100,7 @@ typedef struct png_XYZ
 #endif /* COLORSPACE */
 
 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
-/* A colorspace is all the above plus, potentially, profile information,
+/* A colorspace is all the above plus, potentially, profile information;
  * however at present libpng does not use the profile internally so it is only
  * stored in the png_info struct (if iCCP is supported.)  The rendering intent
  * is retained here and is checked.
@@ -220,16 +219,18 @@ struct png_struct_def
    png_uint_32 row_number;    /* current row in interlace pass */
    png_uint_32 chunk_name;    /* PNG_CHUNK() id of current chunk */
    png_bytep prev_row;        /* buffer to save previous (unfiltered) row.
-                               * This is a pointer into big_prev_row
+                               * While reading this is a pointer into
+                               * big_prev_row; while writing it is separately
+                               * allocated if needed.
                                */
    png_bytep row_buf;         /* buffer to save current (unfiltered) row.
-                               * This is a pointer into big_row_buf
+                               * While reading, this is a pointer into
+                               * big_row_buf; while writing it is separately
+                               * allocated.
                                */
-#ifdef PNG_WRITE_SUPPORTED
-   png_bytep sub_row;         /* buffer to save "sub" row when filtering */
-   png_bytep up_row;          /* buffer to save "up" row when filtering */
-   png_bytep avg_row;         /* buffer to save "avg" row when filtering */
-   png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
+#ifdef PNG_WRITE_FILTER_SUPPORTED
+   png_bytep try_row;    /* buffer to save trial row when filtering */
+   png_bytep tst_row;    /* buffer to save best trial row when filtering */
 #endif
    png_size_t info_rowbytes;  /* Added in 1.5.4: cache of updated row bytes */
 
@@ -274,7 +275,7 @@ struct png_struct_def
 #ifdef PNG_READ_GAMMA_SUPPORTED
    png_color_16 background_1; /* background normalized to gamma 1.0 */
 #endif
-#endif /* PNG_bKGD_SUPPORTED */
+#endif /* bKGD */
 
 #ifdef PNG_WRITE_FLUSH_SUPPORTED
    png_flush_ptr output_flush_fn; /* Function for flushing output */
@@ -331,7 +332,7 @@ struct png_struct_def
    int process_mode;                 /* what push library is currently doing */
    int cur_palette;                  /* current push library palette index */
 
-#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
+#endif /* PROGRESSIVE_READ */
 
 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
 /* For the Borland special 64K segment handler */

pngtest.c

@@ -1,8 +1,8 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.6.11 [June 5, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -283,7 +283,8 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
        png_uint_32 n, nstop;
        int channel;
        int color_channels = row_info->channels;
-       if (row_info->color_type > 3)color_channels--;
+       if (row_info->color_type > 3)
+          color_channels--;
 
        for (n = 0, nstop=row_info->width; n<nstop; n++)
        {
@@ -310,7 +311,7 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
        }
     }
 }
-#endif /* PNG_WRITE_USER_TRANSFORM_SUPPORTED */
+#endif /* WRITE_USER_TRANSFORM */
 
 #ifndef PNG_STDIO_SUPPORTED
 /* START of code to validate stdio-free compilation */
@@ -419,7 +420,7 @@ pngtest_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
    pngtest_check_io_state(png_ptr, length, PNG_IO_WRITING);
 #endif
 }
-#endif /* !PNG_STDIO_SUPPORTED */
+#endif /* !STDIO */
 
 /* This function is called when there is a warning, but the library thinks
  * it can continue anyway.  Replacement functions don't have to do anything
@@ -468,7 +469,7 @@ pngtest_error(png_structp png_ptr, png_const_charp message)
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
 
 /* Allocate memory.  For reasonable files, size should never exceed
- * 64K.  However, zlib may allocate more then 64K if you don't tell
+ * 64K.  However, zlib may allocate more than 64K if you don't tell
  * it not to.  See zconf.h and png.h for more information.  zlib does
  * need to allocate exactly 64K, so whatever you call here must
  * have the ability to do that.
@@ -564,6 +565,7 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
    }
 
    /* Unlink the element from the list. */
+   if (pinformation != NULL)
    {
       memory_infop *ppinfo = &pinformation;
 
@@ -580,15 +582,14 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
             /* We must free the list element too, but first kill
                the memory that is to be freed. */
             memset(ptr, 0x55, pinfo->size);
-            if (pinfo != NULL)
-               free(pinfo);
+            free(pinfo);
             pinfo = NULL;
             break;
          }
 
          if (pinfo->next == NULL)
          {
-            fprintf(STDERR, "Pointer %x not found\n", (unsigned int)ptr);
+            fprintf(STDERR, "Pointer %p not found\n", ptr);
             break;
          }
 
@@ -604,7 +605,7 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
       free(ptr);
    ptr = NULL;
 }
-#endif /* PNG_USER_MEM_SUPPORTED && PNG_DEBUG */
+#endif /* USER_MEM && DEBUG */
 /* END of code to test memory allocation/deallocation */
 
 
@@ -643,16 +644,16 @@ set_location(png_structp png_ptr, struct user_chunk_data *data, int what)
 {
    int location;
 
-   if ((data->location[0] & what) || (data->location[1] & what))
+   if ((data->location[0] & what) != 0 || (data->location[1] & what) != 0)
       return 0; /* already have one of these */
 
-   /* Find where we are (the code below zeros info_ptr to indicate that the
+   /* Find where we are (the code below zeroes info_ptr to indicate that the
     * chunks before the first IDAT have been read.)
     */
    if (data->info_ptr == NULL) /* after IDAT */
       location = what | after_IDAT;
 
-   else if (png_get_valid(png_ptr, data->info_ptr, PNG_INFO_PLTE))
+   else if (png_get_valid(png_ptr, data->info_ptr, PNG_INFO_PLTE) != 0)
       location = what | before_IDAT;
 
    else
@@ -699,7 +700,7 @@ read_user_chunk_callback(png_struct *png_ptr, png_unknown_chunkp chunk)
          if (chunk->data[0] != 0 && chunk->data[0] != 1)
             return (-1);  /* Invalid mode */
 
-         if (set_location(png_ptr, my_user_chunk_data, have_sTER))
+         if (set_location(png_ptr, my_user_chunk_data, have_sTER) != 0)
          {
             my_user_chunk_data->sTER_mode=chunk->data[0];
             return (1);
@@ -718,7 +719,7 @@ read_user_chunk_callback(png_struct *png_ptr, png_unknown_chunkp chunk)
    if (chunk->size != 9)
       return (-1); /* Error return */
 
-   if (!set_location(png_ptr, my_user_chunk_data, have_vpAg))
+   if (set_location(png_ptr, my_user_chunk_data, have_vpAg) == 0)
       return (0);  /* duplicate vpAg */
 
    my_user_chunk_data->vpAg_width = png_get_uint_31(png_ptr, chunk->data);
@@ -779,8 +780,8 @@ write_chunks(png_structp write_ptr, int location)
          write_vpAg_chunk(write_ptr);
    }
 }
-#endif /* PNG_WRITE_SUPPORTED */
-#else /* !PNG_READ_USER_CHUNKS_SUPPORTED */
+#endif /* WRITE */
+#else /* !READ_USER_CHUNKS */
 #  define write_chunks(pp,loc) ((void)0)
 #endif
 /* END of code to demonstrate user chunk support */
@@ -1049,7 +1050,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       int interlace_type, compression_type, filter_type;
 
       if (png_get_IHDR(read_ptr, read_info_ptr, &width, &height, &bit_depth,
-          &color_type, &interlace_type, &compression_type, &filter_type))
+          &color_type, &interlace_type, &compression_type, &filter_type) != 0)
       {
          png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth,
             color_type, interlace_type, compression_type, filter_type);
@@ -1082,7 +1083,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          blue_y;
 
       if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y,
-         &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y))
+         &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
       {
          png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x,
             red_y, green_x, green_y, blue_x, blue_y);
@@ -1093,7 +1094,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_fixed_point gamma;
 
-      if (png_get_gAMA_fixed(read_ptr, read_info_ptr, &gamma))
+      if (png_get_gAMA_fixed(read_ptr, read_info_ptr, &gamma) != 0)
          png_set_gAMA_fixed(write_ptr, write_info_ptr, gamma);
    }
 #endif
@@ -1105,7 +1106,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          blue_y;
 
       if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x,
-         &red_y, &green_x, &green_y, &blue_x, &blue_y))
+         &red_y, &green_x, &green_y, &blue_x, &blue_y) != 0)
       {
          png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x,
             red_y, green_x, green_y, blue_x, blue_y);
@@ -1116,7 +1117,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       double gamma;
 
-      if (png_get_gAMA(read_ptr, read_info_ptr, &gamma))
+      if (png_get_gAMA(read_ptr, read_info_ptr, &gamma) != 0)
          png_set_gAMA(write_ptr, write_info_ptr, gamma);
    }
 #endif
@@ -1130,7 +1131,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       int compression_type;
 
       if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type,
-                      &profile, &proflen))
+                      &profile, &proflen) != 0)
       {
          png_set_iCCP(write_ptr, write_info_ptr, name, compression_type,
                       profile, proflen);
@@ -1141,7 +1142,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       int intent;
 
-      if (png_get_sRGB(read_ptr, read_info_ptr, &intent))
+      if (png_get_sRGB(read_ptr, read_info_ptr, &intent) != 0)
          png_set_sRGB(write_ptr, write_info_ptr, intent);
    }
 #endif
@@ -1149,14 +1150,14 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_colorp palette;
       int num_palette;
 
-      if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette))
+      if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette) != 0)
          png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette);
    }
 #ifdef PNG_bKGD_SUPPORTED
    {
       png_color_16p background;
 
-      if (png_get_bKGD(read_ptr, read_info_ptr, &background))
+      if (png_get_bKGD(read_ptr, read_info_ptr, &background) != 0)
       {
          png_set_bKGD(write_ptr, write_info_ptr, background);
       }
@@ -1166,7 +1167,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_uint_16p hist;
 
-      if (png_get_hIST(read_ptr, read_info_ptr, &hist))
+      if (png_get_hIST(read_ptr, read_info_ptr, &hist) != 0)
          png_set_hIST(write_ptr, write_info_ptr, hist);
    }
 #endif
@@ -1176,7 +1177,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       int unit_type;
 
       if (png_get_oFFs(read_ptr, read_info_ptr, &offset_x, &offset_y,
-          &unit_type))
+          &unit_type) != 0)
       {
          png_set_oFFs(write_ptr, write_info_ptr, offset_x, offset_y, unit_type);
       }
@@ -1190,7 +1191,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       int type, nparams;
 
       if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type,
-         &nparams, &units, &params))
+         &nparams, &units, &params) != 0)
       {
          png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type,
             nparams, units, params);
@@ -1202,7 +1203,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_uint_32 res_x, res_y;
       int unit_type;
 
-      if (png_get_pHYs(read_ptr, read_info_ptr, &res_x, &res_y, &unit_type))
+      if (png_get_pHYs(read_ptr, read_info_ptr, &res_x, &res_y,
+          &unit_type) != 0)
          png_set_pHYs(write_ptr, write_info_ptr, res_x, res_y, unit_type);
    }
 #endif
@@ -1210,7 +1212,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_color_8p sig_bit;
 
-      if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit))
+      if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit) != 0)
          png_set_sBIT(write_ptr, write_info_ptr, sig_bit);
    }
 #endif
@@ -1222,7 +1224,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       double scal_width, scal_height;
 
       if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &scal_width,
-         &scal_height))
+         &scal_height) != 0)
       {
          png_set_sCAL(write_ptr, write_info_ptr, unit, scal_width, scal_height);
       }
@@ -1234,7 +1236,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_charp scal_width, scal_height;
 
       if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &scal_width,
-          &scal_height))
+          &scal_height) != 0)
       {
          png_set_sCAL_s(write_ptr, write_info_ptr, unit, scal_width,
              scal_height);
@@ -1274,11 +1276,11 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_timep mod_time;
 
-      if (png_get_tIME(read_ptr, read_info_ptr, &mod_time))
+      if (png_get_tIME(read_ptr, read_info_ptr, &mod_time) != 0)
       {
          png_set_tIME(write_ptr, write_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
-         if (png_convert_to_rfc1123_buffer(tIME_string, mod_time))
+         if (png_convert_to_rfc1123_buffer(tIME_string, mod_time) != 0)
             tIME_string[(sizeof tIME_string) - 1] = '\0';
 
          else
@@ -1288,7 +1290,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          }
 
          tIME_chunk_present++;
-#endif /* PNG_TIME_RFC1123_SUPPORTED */
+#endif /* TIME_RFC1123 */
       }
    }
 #endif
@@ -1299,7 +1301,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_color_16p trans_color;
 
       if (png_get_tRNS(read_ptr, read_info_ptr, &trans_alpha, &num_trans,
-         &trans_color))
+         &trans_color) != 0)
       {
          int sample_max = (1 << bit_depth);
          /* libpng doesn't reject a tRNS chunk with out-of-range samples */
@@ -1382,11 +1384,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       {
 #ifndef SINGLE_ROWBUF_ALLOC
          pngtest_debug2("Allocating row buffer (pass %d, y = %u)...", pass, y);
+
          row_buf = (png_bytep)png_malloc(read_ptr,
             png_get_rowbytes(read_ptr, read_info_ptr));
 
-         pngtest_debug2("\t0x%08lx (%u bytes)", (unsigned long)row_buf,
-            png_get_rowbytes(read_ptr, read_info_ptr));
+         pngtest_debug2("\t0x%08lx (%lu bytes)", (unsigned long)row_buf,
+            (unsigned long)png_get_rowbytes(read_ptr, read_info_ptr));
 
 #endif /* !SINGLE_ROWBUF_ALLOC */
          png_read_rows(read_ptr, (png_bytepp)&row_buf, NULL, 1);
@@ -1403,7 +1406,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          t_encode += (t_stop - t_start);
          t_start = t_stop;
 #endif
-#endif /* PNG_WRITE_SUPPORTED */
+#endif /* WRITE */
 
 #ifndef SINGLE_ROWBUF_ALLOC
          pngtest_debug2("Freeing row buffer (pass %d, y = %u)", pass, y);
@@ -1456,11 +1459,11 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       png_timep mod_time;
 
-      if (png_get_tIME(read_ptr, end_info_ptr, &mod_time))
+      if (png_get_tIME(read_ptr, end_info_ptr, &mod_time) != 0)
       {
          png_set_tIME(write_ptr, write_end_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
-         if (png_convert_to_rfc1123_buffer(tIME_string, mod_time))
+         if (png_convert_to_rfc1123_buffer(tIME_string, mod_time) != 0)
             tIME_string[(sizeof tIME_string) - 1] = '\0';
 
          else
@@ -1470,7 +1473,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          }
 
          tIME_chunk_present++;
-#endif /* PNG_TIME_RFC1123_SUPPORTED */
+#endif /* TIME_RFC1123 */
       }
    }
 #endif
@@ -1675,7 +1678,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          }
       }
    }
-#endif /* PNG_WRITE_SUPPORTED */
+#endif /* WRITE */
 
    FCLOSE(fpin);
    FCLOSE(fpout);
@@ -1698,6 +1701,8 @@ main(int argc, char *argv[])
    int multiple = 0;
    int ierror = 0;
 
+   png_structp dummy_ptr;
+
    fprintf(STDERR, "\n Testing libpng version %s\n", PNG_LIBPNG_VER_STRING);
    fprintf(STDERR, "   with zlib   version %s\n", ZLIB_VERSION);
    fprintf(STDERR, "%s", png_get_copyright(NULL));
@@ -1780,10 +1785,11 @@ main(int argc, char *argv[])
       }
    }
 
-   if (!multiple && argc == 3 + verbose)
+   if (multiple == 0 && argc == 3 + verbose)
      outname = argv[2 + verbose];
 
-   if ((!multiple && argc > 3 + verbose) || (multiple && argc < 2))
+   if ((multiple == 0 && argc > 3 + verbose) ||
+       (multiple != 0 && argc < 2))
    {
      fprintf(STDERR,
        "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
@@ -1805,6 +1811,9 @@ main(int argc, char *argv[])
       {
          int kerror;
          fprintf(STDERR, "\n Testing %s:", argv[i]);
+#if PNG_DEBUG > 0
+         fprintf(STDERR, "\n");
+#endif
          kerror = test_one_file(argv[i], outname);
          if (kerror == 0)
          {
@@ -1819,16 +1828,16 @@ main(int argc, char *argv[])
 #endif
 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
             for (k = 0; k<256; k++)
-               if (filters_used[k])
+               if (filters_used[k] != 0)
                   fprintf(STDERR, " Filter %d was used %lu times\n",
                      k, (unsigned long)filters_used[k]);
 #endif
 #ifdef PNG_TIME_RFC1123_SUPPORTED
-         if (tIME_chunk_present != 0)
-            fprintf(STDERR, " tIME = %s\n", tIME_string);
+            if (tIME_chunk_present != 0)
+               fprintf(STDERR, " tIME = %s\n", tIME_string);
 
-         tIME_chunk_present = 0;
-#endif /* PNG_TIME_RFC1123_SUPPORTED */
+            tIME_chunk_present = 0;
+#endif /* TIME_RFC1123 */
          }
 
          else
@@ -1850,9 +1859,9 @@ main(int argc, char *argv[])
 
             while (pinfo != NULL)
             {
-               fprintf(STDERR, " %lu bytes at %x\n",
+               fprintf(STDERR, " %lu bytes at %p\n",
                  (unsigned long)pinfo->size,
-                 (unsigned int)pinfo->pointer);
+                 pinfo->pointer);
                pinfo = pinfo->next;
             }
          }
@@ -1886,7 +1895,12 @@ main(int argc, char *argv[])
             status_dots_requested = 0;
 
          if (i == 0 || verbose == 1 || ierror != 0)
+         {
             fprintf(STDERR, "\n Testing %s:", inname);
+#if PNG_DEBUG > 0
+            fprintf(STDERR, "\n");
+#endif
+         }
 
          kerror = test_one_file(inname, outname);
 
@@ -1905,21 +1919,26 @@ main(int argc, char *argv[])
 #endif
 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
                 for (k = 0; k<256; k++)
-                   if (filters_used[k])
+                   if (filters_used[k] != 0)
                       fprintf(STDERR, " Filter %d was used %lu times\n",
                          k, (unsigned long)filters_used[k]);
 #endif
 #ifdef PNG_TIME_RFC1123_SUPPORTED
              if (tIME_chunk_present != 0)
                 fprintf(STDERR, " tIME = %s\n", tIME_string);
-#endif /* PNG_TIME_RFC1123_SUPPORTED */
+#endif /* TIME_RFC1123 */
             }
          }
 
          else
          {
             if (verbose == 0 && i != 2)
+            {
                fprintf(STDERR, "\n Testing %s:", inname);
+#if PNG_DEBUG > 0
+               fprintf(STDERR, "\n");
+#endif
+            }
 
             fprintf(STDERR, " FAIL\n");
             ierror += kerror;
@@ -1938,8 +1957,8 @@ main(int argc, char *argv[])
 
              while (pinfo != NULL)
              {
-                fprintf(STDERR, " %lu bytes at %x\n",
-                   (unsigned long)pinfo->size, (unsigned int)pinfo->pointer);
+                fprintf(STDERR, " %lu bytes at %p\n",
+                   (unsigned long)pinfo->size, pinfo->pointer);
                 pinfo = pinfo->next;
              }
           }
@@ -1977,6 +1996,24 @@ main(int argc, char *argv[])
    else
       fprintf(STDERR, " libpng FAILS test\n");
 
+   dummy_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+   fprintf(STDERR, " Default limits:\n");
+   fprintf(STDERR, "  width_max  = %lu\n",
+      (unsigned long) png_get_user_width_max(dummy_ptr));
+   fprintf(STDERR, "  height_max = %lu\n",
+      (unsigned long) png_get_user_height_max(dummy_ptr));
+   if (png_get_chunk_cache_max(dummy_ptr) == 0)
+      fprintf(STDERR, "  cache_max  = unlimited\n");
+   else
+      fprintf(STDERR, "  cache_max  = %lu\n",
+         (unsigned long) png_get_chunk_cache_max(dummy_ptr));
+   if (png_get_chunk_malloc_max(dummy_ptr) == 0)
+      fprintf(STDERR, "  malloc_max = unlimited\n");
+   else
+      fprintf(STDERR, "  malloc_max = %lu\n",
+         (unsigned long) png_get_chunk_malloc_max(dummy_ptr));
+   png_destroy_read_struct(&dummy_ptr, NULL, NULL);
+
    return (int)(ierror != 0);
 }
 #else
@@ -1991,4 +2028,4 @@ main(void)
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_13 Your_png_h_is_not_version_1_6_13;
+typedef png_libpng_version_1_6_18beta05 Your_png_h_is_not_version_1_6_18beta05;

pngtrans.c

@@ -1,8 +1,8 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.6.11 [June 5, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -100,7 +100,7 @@ png_set_interlace_handling(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_interlace handling");
 
-   if (png_ptr && png_ptr->interlaced)
+   if (png_ptr != 0 && png_ptr->interlaced != 0)
    {
       png_ptr->transformations |= PNG_INTERLACE;
       return (7);
@@ -127,7 +127,7 @@ png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
    /* In libpng 1.6 it is possible to determine whether this is a read or write
     * operation and therefore to do more checking here for a valid call.
     */
-   if (png_ptr->mode & PNG_IS_READ_STRUCT)
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
    {
 #     ifdef PNG_READ_FILLER_SUPPORTED
          /* On read png_set_filler is always valid, regardless of the base PNG
@@ -210,7 +210,7 @@ png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
 
    png_set_filler(png_ptr, filler, filler_loc);
    /* The above may fail to do anything. */
-   if (png_ptr->transformations & PNG_FILLER)
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
       png_ptr->transformations |= PNG_ADD_ALPHA;
 }
 
@@ -478,7 +478,7 @@ png_do_packswap(png_row_infop row_info, png_bytep row)
          *rp = table[*rp];
    }
 }
-#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */
+#endif /* PACKSWAP || WRITE_PACKSWAP */
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
@@ -605,7 +605,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_bgr");
 
-   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       png_uint_32 row_width = row_info->width;
       if (row_info->bit_depth == 8)
@@ -675,7 +675,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
 #endif
    }
 }
-#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
+#endif /* READ_BGR || WRITE_BGR */
 
 #if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
     defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
@@ -704,7 +704,7 @@ png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
              */
             for (; rp > png_ptr->row_buf; rp--)
             {
-              if (*rp >> padding != 0)
+              if ((*rp >> padding) != 0)
                  png_ptr->num_palette_max = 1;
               padding = 0;
             }
@@ -778,7 +778,7 @@ png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
       }
    }
 }
-#endif /* PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED */
+#endif /* CHECK_FOR_INVALID_INDEX */
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
@@ -828,7 +828,7 @@ png_get_user_transform_ptr(png_const_structrp png_ptr)
 png_uint_32 PNGAPI
 png_get_current_row_number(png_const_structrp png_ptr)
 {
-   /* See the comments in png.h - this is the sub-image row when reading and
+   /* See the comments in png.h - this is the sub-image row when reading an
     * interlaced image.
     */
    if (png_ptr != NULL)
@@ -844,7 +844,6 @@ png_get_current_pass_number(png_const_structrp png_ptr)
       return png_ptr->pass;
    return 8; /* invalid */
 }
-#endif /* PNG_USER_TRANSFORM_INFO_SUPPORTED */
-#endif /* PNG_READ_USER_TRANSFORM_SUPPORTED ||
-          PNG_WRITE_USER_TRANSFORM_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+#endif /* USER_TRANSFORM_INFO */
+#endif /* READ_USER_TRANSFORM || WRITE_USER_TRANSFORM */
+#endif /* READ || WRITE */

pngusr.dfa

@@ -8,7 +8,7 @@
 # here by entering the appropriate values as #defines preceded by '@' (to cause,
 # them to be passed through to the build of pnglibconf.h), for example:
 #
-# @# define PNG_USER_WIDTH_MAX 1000000
-# @# define PNG_USER_HEIGHT_MAX 1000000
-# @# define PNG_USER_CHUNK_CACHE_MAX 128
-# @# define PNG_USER_CHUNK_MALLOC_MAX 8000000
+# @# define PNG_USER_WIDTH_MAX 65535
+# @# define PNG_USER_HEIGHT_MAX 65535
+# @# define PNG_USER_CHUNK_CACHE_MAX 256
+# @# define PNG_USER_CHUNK_MALLOC_MAX 640000

pngwio.c

@@ -1,7 +1,7 @@
 
 /* pngwio.c - functions for data output
  *
- * Last changed in libpng 1.6.9 [February 6, 2014]
+ * Last changed in libpng 1.6.15 [November 20, 2014]
  * Copyright (c) 1998-2014 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.)
@@ -151,7 +151,7 @@ png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
 #  endif
 #else
    PNG_UNUSED(output_flush_fn)
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+#endif /* WRITE_FLUSH */
 
 #ifdef PNG_READ_SUPPORTED
    /* It is an error to read while writing a png file */
@@ -165,4 +165,4 @@ png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
    }
 #endif
 }
-#endif /* PNG_WRITE_SUPPORTED */
+#endif /* WRITE */

pngwrite.c

@@ -1,8 +1,8 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.6.11 [June 5, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -24,7 +24,7 @@ static void
 write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
    unsigned int where)
 {
-   if (info_ptr->unknown_chunks_num)
+   if (info_ptr->unknown_chunks_num != 0)
    {
       png_const_unknown_chunkp up;
 
@@ -33,7 +33,7 @@ write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
       for (up = info_ptr->unknown_chunks;
            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
            ++up)
-         if (up->location & where)
+         if ((up->location & where) != 0)
       {
          /* If per-chunk unknown chunk handling is enabled use it, otherwise
           * just write the chunks the application has set.
@@ -69,7 +69,7 @@ write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr,
       }
    }
 }
-#endif /* PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED */
+#endif /* WRITE_UNKNOWN_CHUNKS */
 
 /* Writes all the PNG information.  This is the suggested way to use the
  * library.  If you have a new chunk to add, make a function to write it,
@@ -88,14 +88,14 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+   if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
    {
    /* Write PNG signature */
    png_write_sig(png_ptr);
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
-   if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
-       (png_ptr->mng_features_permitted))
+   if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \
+       png_ptr->mng_features_permitted != 0)
    {
       png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
       png_ptr->mng_features_permitted = 0;
@@ -129,9 +129,9 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
     */
 #ifdef PNG_GAMMA_SUPPORTED
 #  ifdef PNG_WRITE_gAMA_SUPPORTED
-      if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
-         (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) &&
-         (info_ptr->valid & PNG_INFO_gAMA))
+      if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+          (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 &&
+          (info_ptr->valid & PNG_INFO_gAMA) != 0)
          png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma);
 #  endif
 #endif
@@ -141,11 +141,11 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
     * and it matches one of the known sRGB ones issue a warning.
     */
 #  ifdef PNG_WRITE_iCCP_SUPPORTED
-      if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
-         (info_ptr->valid & PNG_INFO_iCCP))
+      if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+          (info_ptr->valid & PNG_INFO_iCCP) != 0)
       {
 #        ifdef PNG_WRITE_sRGB_SUPPORTED
-            if (info_ptr->valid & PNG_INFO_sRGB)
+            if ((info_ptr->valid & PNG_INFO_sRGB) != 0)
                png_app_warning(png_ptr,
                   "profile matches sRGB but writing iCCP instead");
 #        endif
@@ -159,22 +159,22 @@ png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
 #  endif
 
 #  ifdef PNG_WRITE_sRGB_SUPPORTED
-      if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
-         (info_ptr->valid & PNG_INFO_sRGB))
+      if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+          (info_ptr->valid & PNG_INFO_sRGB) != 0)
          png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent);
 #  endif /* WRITE_sRGB */
 #endif /* COLORSPACE */
 
 #ifdef PNG_WRITE_sBIT_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_sBIT)
+   if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
       png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
 #endif
 
 #ifdef PNG_COLORSPACE_SUPPORTED
 #  ifdef PNG_WRITE_cHRM_SUPPORTED
-      if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) &&
-         (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) &&
-         (info_ptr->valid & PNG_INFO_cHRM))
+      if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 &&
+         (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 &&
+         (info_ptr->valid & PNG_INFO_cHRM) != 0)
          png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy);
 #  endif
 #endif
@@ -201,23 +201,28 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
 
    png_write_info_before_PLTE(png_ptr, info_ptr);
 
-   if (info_ptr->valid & PNG_INFO_PLTE)
+   if ((info_ptr->valid & PNG_INFO_PLTE) != 0)
       png_write_PLTE(png_ptr, info_ptr->palette,
           (png_uint_32)info_ptr->num_palette);
 
-   else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+   else if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) !=0)
       png_error(png_ptr, "Valid palette required for paletted images");
 
 #ifdef PNG_WRITE_tRNS_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_tRNS)
+   if ((info_ptr->valid & PNG_INFO_tRNS) !=0)
    {
 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
       /* Invert the alpha channel (in tRNS) */
-      if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
+      if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 &&
           info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       {
-         int j;
-         for (j = 0; j<(int)info_ptr->num_trans; j++)
+         int j, jend;
+
+         jend = info_ptr->num_trans;
+         if (jend > PNG_MAX_PALETTE_LENGTH)
+            jend = PNG_MAX_PALETTE_LENGTH;
+
+         for (j = 0; j<jend; ++j)
             info_ptr->trans_alpha[j] =
                (png_byte)(255 - info_ptr->trans_alpha[j]);
       }
@@ -227,42 +232,42 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
    }
 #endif
 #ifdef PNG_WRITE_bKGD_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_bKGD)
+   if ((info_ptr->valid & PNG_INFO_bKGD) != 0)
       png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
 #endif
 
 #ifdef PNG_WRITE_hIST_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_hIST)
+   if ((info_ptr->valid & PNG_INFO_hIST) != 0)
       png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
 #endif
 
 #ifdef PNG_WRITE_oFFs_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_oFFs)
+   if ((info_ptr->valid & PNG_INFO_oFFs) != 0)
       png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
           info_ptr->offset_unit_type);
 #endif
 
 #ifdef PNG_WRITE_pCAL_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_pCAL)
+   if ((info_ptr->valid & PNG_INFO_pCAL) != 0)
       png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
           info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
           info_ptr->pcal_units, info_ptr->pcal_params);
 #endif
 
 #ifdef PNG_WRITE_sCAL_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_sCAL)
+   if ((info_ptr->valid & PNG_INFO_sCAL) != 0)
       png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
           info_ptr->scal_s_width, info_ptr->scal_s_height);
 #endif /* sCAL */
 
 #ifdef PNG_WRITE_pHYs_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_pHYs)
+   if ((info_ptr->valid & PNG_INFO_pHYs) != 0)
       png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
           info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
 #endif /* pHYs */
 
 #ifdef PNG_WRITE_tIME_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_tIME)
+   if ((info_ptr->valid & PNG_INFO_tIME) != 0)
    {
       png_write_tIME(png_ptr, &(info_ptr->mod_time));
       png_ptr->mode |= PNG_WROTE_tIME;
@@ -270,7 +275,7 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
 #endif /* tIME */
 
 #ifdef PNG_WRITE_sPLT_SUPPORTED
-   if (info_ptr->valid & PNG_INFO_sPLT)
+   if ((info_ptr->valid & PNG_INFO_sPLT) != 0)
       for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
          png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
 #endif /* sPLT */
@@ -292,11 +297,14 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
              info_ptr->text[i].lang,
              info_ptr->text[i].lang_key,
              info_ptr->text[i].text);
+         /* Mark this chunk as written */
+         if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+         else
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
 #else
-          png_warning(png_ptr, "Unable to write international text");
+         png_warning(png_ptr, "Unable to write international text");
 #endif
-          /* Mark this chunk as written */
-          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
       }
 
       /* If we want a compressed text chunk */
@@ -305,13 +313,12 @@ png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
 #ifdef PNG_WRITE_zTXt_SUPPORTED
          /* Write compressed chunk */
          png_write_zTXt(png_ptr, info_ptr->text[i].key,
-             info_ptr->text[i].text, 0,
-             info_ptr->text[i].compression);
+             info_ptr->text[i].text, info_ptr->text[i].compression);
+         /* Mark this chunk as written */
+         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
 #else
          png_warning(png_ptr, "Unable to write compressed text");
 #endif
-         /* Mark this chunk as written */
-         info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
       }
 
       else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
@@ -349,7 +356,7 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
    if (png_ptr == NULL)
       return;
 
-   if (!(png_ptr->mode & PNG_HAVE_IDAT))
+   if ((png_ptr->mode & PNG_HAVE_IDAT) == 0)
       png_error(png_ptr, "No IDATs written into file");
 
 #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
@@ -365,8 +372,8 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
 #endif
 #ifdef PNG_WRITE_tIME_SUPPORTED
       /* Check to see if user has supplied a time chunk */
-      if ((info_ptr->valid & PNG_INFO_tIME) &&
-          !(png_ptr->mode & PNG_WROTE_tIME))
+      if ((info_ptr->valid & PNG_INFO_tIME) != 0 &&
+          (png_ptr->mode & PNG_WROTE_tIME) == 0)
          png_write_tIME(png_ptr, &(info_ptr->mod_time));
 
 #endif
@@ -387,11 +394,14 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
                 info_ptr->text[i].lang,
                 info_ptr->text[i].lang_key,
                 info_ptr->text[i].text);
+            /* Mark this chunk as written */
+            if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
+               info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+            else
+               info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
 #else
             png_warning(png_ptr, "Unable to write international text");
 #endif
-            /* Mark this chunk as written */
-            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
          }
 
          else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
@@ -399,13 +409,12 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
 #ifdef PNG_WRITE_zTXt_SUPPORTED
             /* Write compressed chunk */
             png_write_zTXt(png_ptr, info_ptr->text[i].key,
-                info_ptr->text[i].text, 0,
-                info_ptr->text[i].compression);
+                info_ptr->text[i].text, info_ptr->text[i].compression);
+            /* Mark this chunk as written */
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
 #else
             png_warning(png_ptr, "Unable to write compressed text");
 #endif
-            /* Mark this chunk as written */
-            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
          }
 
          else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
@@ -414,12 +423,11 @@ png_write_end(png_structrp png_ptr, png_inforp info_ptr)
             /* Write uncompressed chunk */
             png_write_tEXt(png_ptr, info_ptr->text[i].key,
                 info_ptr->text[i].text, 0);
+            /* Mark this chunk as written */
+            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
 #else
             png_warning(png_ptr, "Unable to write uncompressed text");
 #endif
-
-            /* Mark this chunk as written */
-            info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
          }
       }
 #endif
@@ -494,7 +502,7 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
 {
    png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
        error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
-#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* USER_MEM */
    if (png_ptr != NULL)
    {
       /* Set the zlib control values to defaults; they can be overridden by the
@@ -518,7 +526,7 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
       png_ptr->zlib_text_mem_level = 8;
       png_ptr->zlib_text_window_bits = 15;
       png_ptr->zlib_text_method = 8;
-#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
+#endif /* WRITE_COMPRESSED_TEXT */
 
       /* This is a highly dubious configuration option; by default it is off,
        * but it may be appropriate for private builds that are testing
@@ -535,7 +543,7 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
       /* App warnings are warnings in release (or release candidate) builds but
        * are errors during development.
        */
-#if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
+#if PNG_RELEASE_BUILD
       png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
 #endif
 
@@ -615,7 +623,7 @@ png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
 {
    png_debug(1, "in png_do_write_intrapixel");
 
-   if ((row_info->color_type & PNG_COLOR_MASK_COLOR))
+   if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       int bytes_per_pixel;
       png_uint_32 row_width = row_info->width;
@@ -635,8 +643,8 @@ png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
 
          for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
          {
-            *(rp)     = (png_byte)((*rp       - *(rp + 1)) & 0xff);
-            *(rp + 2) = (png_byte)((*(rp + 2) - *(rp + 1)) & 0xff);
+            *(rp)     = (png_byte)(*rp       - *(rp + 1));
+            *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1));
          }
       }
 
@@ -662,16 +670,16 @@ png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
             png_uint_32 s2   = (*(rp + 4) << 8) | *(rp + 5);
             png_uint_32 red  = (png_uint_32)((s0 - s1) & 0xffffL);
             png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
-            *(rp    ) = (png_byte)((red >> 8) & 0xff);
-            *(rp + 1) = (png_byte)(red & 0xff);
-            *(rp + 4) = (png_byte)((blue >> 8) & 0xff);
-            *(rp + 5) = (png_byte)(blue & 0xff);
+            *(rp    ) = (png_byte)(red >> 8);
+            *(rp + 1) = (png_byte)red;
+            *(rp + 4) = (png_byte)(blue >> 8);
+            *(rp + 5) = (png_byte)blue;
          }
       }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
+#endif /* WRITE_16BIT */
    }
 }
-#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* MNG_FEATURES */
 
 /* Called by user to write a row of image data */
 void PNGAPI
@@ -690,44 +698,44 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
    if (png_ptr->row_number == 0 && png_ptr->pass == 0)
    {
       /* Make sure we wrote the header info */
-      if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+      if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0)
          png_error(png_ptr,
              "png_write_info was never called before png_write_row");
 
       /* Check for transforms that have been set but were defined out */
 #if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
-      if (png_ptr->transformations & PNG_INVERT_MONO)
+      if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
          png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
 #endif
 
 #if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
-      if (png_ptr->transformations & PNG_FILLER)
+      if ((png_ptr->transformations & PNG_FILLER) != 0)
          png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
 #endif
 #if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
     defined(PNG_READ_PACKSWAP_SUPPORTED)
-      if (png_ptr->transformations & PNG_PACKSWAP)
+      if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
          png_warning(png_ptr,
              "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
 #endif
 
 #if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
-      if (png_ptr->transformations & PNG_PACK)
+      if ((png_ptr->transformations & PNG_PACK) != 0)
          png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
 #endif
 
 #if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
-      if (png_ptr->transformations & PNG_SHIFT)
+      if ((png_ptr->transformations & PNG_SHIFT) != 0)
          png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
 #endif
 
 #if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
-      if (png_ptr->transformations & PNG_BGR)
+      if ((png_ptr->transformations & PNG_BGR) != 0)
          png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
 #endif
 
 #if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
-      if (png_ptr->transformations & PNG_SWAP_BYTES)
+      if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
          png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
 #endif
 
@@ -736,12 +744,13 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* If interlaced and not interested in row, return */
-   if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
+   if (png_ptr->interlaced != 0 &&
+       (png_ptr->transformations & PNG_INTERLACE) != 0)
    {
       switch (png_ptr->pass)
       {
          case 0:
-            if (png_ptr->row_number & 0x07)
+            if ((png_ptr->row_number & 0x07) != 0)
             {
                png_write_finish_row(png_ptr);
                return;
@@ -749,7 +758,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
             break;
 
          case 1:
-            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
+            if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5)
             {
                png_write_finish_row(png_ptr);
                return;
@@ -765,7 +774,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
             break;
 
          case 3:
-            if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
+            if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3)
             {
                png_write_finish_row(png_ptr);
                return;
@@ -781,7 +790,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
             break;
 
          case 5:
-            if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
+            if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2)
             {
                png_write_finish_row(png_ptr);
                return;
@@ -789,7 +798,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
             break;
 
          case 6:
-            if (!(png_ptr->row_number & 0x01))
+            if ((png_ptr->row_number & 0x01) == 0)
             {
                png_write_finish_row(png_ptr);
                return;
@@ -823,7 +832,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* Handle interlacing */
    if (png_ptr->interlaced && png_ptr->pass < 6 &&
-       (png_ptr->transformations & PNG_INTERLACE))
+       (png_ptr->transformations & PNG_INTERLACE) != 0)
    {
       png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
       /* This should always get caught above, but still ... */
@@ -837,7 +846,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
 
 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
    /* Handle other transformations */
-   if (png_ptr->transformations)
+   if (png_ptr->transformations != 0)
       png_do_write_transformations(png_ptr, &row_info);
 #endif
 
@@ -858,7 +867,7 @@ png_write_row(png_structrp png_ptr, png_const_bytep row)
     * 4. The filter_method is 64 and
     * 5. The color_type is RGB or RGBA
     */
-   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
        (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */
@@ -911,7 +920,7 @@ png_write_flush(png_structrp png_ptr)
    png_ptr->flush_rows = 0;
    png_flush(png_ptr);
 }
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+#endif /* WRITE_FLUSH */
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
 static void png_reset_filter_heuristics(png_structrp png_ptr);/* forward decl */
@@ -924,18 +933,20 @@ png_write_destroy(png_structrp png_ptr)
    png_debug(1, "in png_write_destroy");
 
    /* Free any memory zlib uses */
-   if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
+   if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
       deflateEnd(&png_ptr->zstream);
 
    /* Free our memory.  png_free checks NULL for us. */
    png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
    png_free(png_ptr, png_ptr->row_buf);
+   png_ptr->row_buf = NULL;
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    png_free(png_ptr, png_ptr->prev_row);
-   png_free(png_ptr, png_ptr->sub_row);
-   png_free(png_ptr, png_ptr->up_row);
-   png_free(png_ptr, png_ptr->avg_row);
-   png_free(png_ptr, png_ptr->paeth_row);
+   png_free(png_ptr, png_ptr->try_row);
+   png_free(png_ptr, png_ptr->tst_row);
+   png_ptr->prev_row = NULL;
+   png_ptr->try_row = NULL;
+   png_ptr->tst_row = NULL;
 #endif
 
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
@@ -943,10 +954,13 @@ png_write_destroy(png_structrp png_ptr)
    png_reset_filter_heuristics(png_ptr);
    png_free(png_ptr, png_ptr->filter_costs);
    png_free(png_ptr, png_ptr->inv_filter_costs);
+   png_ptr->filter_costs = NULL;
+   png_ptr->inv_filter_costs = NULL;
 #endif
 
 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
    png_free(png_ptr, png_ptr->chunk_list);
+   png_ptr->chunk_list = NULL;
 #endif
 
    /* The error handling and memory handling information is left intact at this
@@ -992,7 +1006,7 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
       return;
 
 #ifdef PNG_MNG_FEATURES_SUPPORTED
-   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 &&
        (method == PNG_INTRAPIXEL_DIFFERENCING))
       method = PNG_FILTER_TYPE_BASE;
 
@@ -1006,7 +1020,7 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
          case 6:
          case 7: png_app_error(png_ptr, "Unknown row filter for method 0");
             /* FALL THROUGH */
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
+#endif /* WRITE_FILTER */
          case PNG_FILTER_VALUE_NONE:
             png_ptr->do_filter = PNG_FILTER_NONE; break;
 
@@ -1028,7 +1042,7 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
 #else
          default:
             png_app_error(png_ptr, "Unknown row filter for method 0");
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
+#endif /* WRITE_FILTER */
       }
 
       /* If we have allocated the row_buf, this means we have already started
@@ -1037,74 +1051,69 @@ png_set_filter(png_structrp png_ptr, int method, int filters)
        * it is too late to start using the filters that need it, since we
        * will be missing the data in the previous row.  If an application
        * wants to start and stop using particular filters during compression,
-       * it should start out with all of the filters, and then add and
-       * remove them after the start of compression.
+       * it should start out with all of the filters, and then remove them
+       * or add them back after the start of compression.
+       *
+       * NOTE: this is a nasty constraint on the code, because it means that the
+       * prev_row buffer must be maintained even if there are currently no
+       * 'prev_row' requiring filters active.
        */
       if (png_ptr->row_buf != NULL)
       {
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-         if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
+         int num_filters;
+         png_alloc_size_t buf_size;
+
+         /* Repeat the checks in png_write_start_row; 1 pixel high or wide
+          * images cannot benefit from certain filters.  If this isn't done here
+          * the check below will fire on 1 pixel high images.
+          */
+         if (png_ptr->height == 1)
+            filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+         if (png_ptr->width == 1)
+            filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH);
+
+         if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0
+            && png_ptr->prev_row == NULL)
          {
-            png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
-                (png_ptr->rowbytes + 1));
-            png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
+            /* This is the error case, however it is benign - the previous row
+             * is not available so the filter can't be used.  Just warn here.
+             */
+            png_app_warning(png_ptr,
+               "png_set_filter: UP/AVG/PAETH cannot be added after start");
+            filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH);
          }
 
-         if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
+         num_filters = 0;
+
+         if (filters & PNG_FILTER_SUB)
+            num_filters++;
+
+         if (filters & PNG_FILTER_UP)
+            num_filters++;
+
+         if (filters & PNG_FILTER_AVG)
+            num_filters++;
+
+         if (filters & PNG_FILTER_PAETH)
+            num_filters++;
+
+         /* Allocate needed row buffers if they have not already been
+          * allocated.
+          */
+         buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth,
+             png_ptr->width) + 1;
+
+         if (png_ptr->try_row == NULL)
+            png_ptr->try_row = png_malloc(png_ptr, buf_size);
+
+         if (num_filters > 1)
          {
-            if (png_ptr->prev_row == NULL)
-            {
-               png_warning(png_ptr, "Can't add Up filter after starting");
-               png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
-                   ~PNG_FILTER_UP);
-            }
-
-            else
-            {
-               png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
-                   (png_ptr->rowbytes + 1));
-               png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
-            }
+            if (png_ptr->tst_row == NULL)
+               png_ptr->tst_row = png_malloc(png_ptr, buf_size);
          }
-
-         if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
-         {
-            if (png_ptr->prev_row == NULL)
-            {
-               png_warning(png_ptr, "Can't add Average filter after starting");
-               png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
-                   ~PNG_FILTER_AVG);
-            }
-
-            else
-            {
-               png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
-                   (png_ptr->rowbytes + 1));
-               png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
-            }
-         }
-
-         if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
-             png_ptr->paeth_row == NULL)
-         {
-            if (png_ptr->prev_row == NULL)
-            {
-               png_warning(png_ptr, "Can't add Paeth filter after starting");
-               png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
-            }
-
-            else
-            {
-               png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
-                   (png_ptr->rowbytes + 1));
-               png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
-            }
-         }
-
-         if (png_ptr->do_filter == PNG_NO_FILTERS)
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
-            png_ptr->do_filter = PNG_FILTER_NONE;
       }
+      png_ptr->do_filter = (png_byte)filters;
    }
    else
       png_error(png_ptr, "Unknown custom filter method");
@@ -1245,7 +1254,7 @@ png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method,
    /* The internal API allocates all the arrays and ensures that the elements of
     * those arrays are set to the default value.
     */
-   if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
+   if (png_init_filter_heuristics(png_ptr, heuristic_method, num_weights) == 0)
       return;
 
    /* If using the weighted method copy in the weights. */
@@ -1300,7 +1309,7 @@ png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
    /* The internal API allocates all the arrays and ensures that the elements of
     * those arrays are set to the default value.
     */
-   if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
+   if (png_init_filter_heuristics(png_ptr, heuristic_method, num_weights) == 0)
       return;
 
    /* If using the weighted method copy in the weights. */
@@ -1354,8 +1363,9 @@ png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method,
    }
 }
 #endif /* FIXED_POINT */
-#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+#endif /* WRITE_WEIGHTED_FILTER */
 
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
 void PNGAPI
 png_set_compression_level(png_structrp png_ptr, int level)
 {
@@ -1401,8 +1411,8 @@ png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
    if (png_ptr == NULL)
       return;
 
-   /* Prior to 1.6.0 this would warn but then set the window_bits value, this
-    * meant that negative window bits values could be selected which would cause
+   /* Prior to 1.6.0 this would warn but then set the window_bits value. This
+    * meant that negative window bits values could be selected that would cause
     * libpng to write a non-standard PNG file with raw deflate or gzip
     * compressed IDAT or ancillary chunks.  Such files can be read and there is
     * no warning on read, so this seems like a very bad idea.
@@ -1438,6 +1448,7 @@ png_set_compression_method(png_structrp png_ptr, int method)
 
    png_ptr->zlib_method = method;
 }
+#endif /* WRITE_CUSTOMIZE_COMPRESSION */
 
 /* The following were added to libpng-1.5.4 */
 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
@@ -1511,7 +1522,7 @@ png_set_text_compression_method(png_structrp png_ptr, int method)
 
    png_ptr->zlib_text_method = method;
 }
-#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
+#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
 /* end of API added to libpng-1.5.4 */
 
 void PNGAPI
@@ -1559,7 +1570,7 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
    /* ------ these transformations don't touch the info structure ------- */
 
    /* Invert monochrome pixels */
-   if (transforms & PNG_TRANSFORM_INVERT_MONO)
+   if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0)
 #ifdef PNG_WRITE_INVERT_SUPPORTED
       png_set_invert_mono(png_ptr);
 #else
@@ -1569,16 +1580,16 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
    /* Shift the pixels up to a legal bit depth and fill in
     * as appropriate to correctly scale the image.
     */
-   if (transforms & PNG_TRANSFORM_SHIFT)
+   if ((transforms & PNG_TRANSFORM_SHIFT) != 0)
 #ifdef PNG_WRITE_SHIFT_SUPPORTED
-      if (info_ptr->valid & PNG_INFO_sBIT)
+      if ((info_ptr->valid & PNG_INFO_sBIT) != 0)
          png_set_shift(png_ptr, &info_ptr->sig_bit);
 #else
       png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported");
 #endif
 
    /* Pack pixels into bytes */
-   if (transforms & PNG_TRANSFORM_PACKING)
+   if ((transforms & PNG_TRANSFORM_PACKING) != 0)
 #ifdef PNG_WRITE_PACK_SUPPORTED
       png_set_packing(png_ptr);
 #else
@@ -1586,7 +1597,7 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
 #endif
 
    /* Swap location of alpha bytes from ARGB to RGBA */
-   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+   if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0)
 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
       png_set_swap_alpha(png_ptr);
 #else
@@ -1597,13 +1608,13 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
     * RGB, note that the code expects the input color type to be G or RGB; no
     * alpha channel.
     */
-   if (transforms &
-      (PNG_TRANSFORM_STRIP_FILLER_AFTER|PNG_TRANSFORM_STRIP_FILLER_BEFORE))
+   if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER|
+      PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0)
    {
 #ifdef PNG_WRITE_FILLER_SUPPORTED
-      if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
+      if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0)
       {
-         if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
+         if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
             png_app_error(png_ptr,
                "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported");
 
@@ -1611,7 +1622,7 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
          png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
       }
 
-      else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
+      else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0)
          png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
 #else
       png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported");
@@ -1619,7 +1630,7 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
    }
 
    /* Flip BGR pixels to RGB */
-   if (transforms & PNG_TRANSFORM_BGR)
+   if ((transforms & PNG_TRANSFORM_BGR) != 0)
 #ifdef PNG_WRITE_BGR_SUPPORTED
       png_set_bgr(png_ptr);
 #else
@@ -1627,7 +1638,7 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
 #endif
 
    /* Swap bytes of 16-bit files to most significant byte first */
-   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+   if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0)
 #ifdef PNG_WRITE_SWAP_SUPPORTED
       png_set_swap(png_ptr);
 #else
@@ -1635,7 +1646,7 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
 #endif
 
    /* Swap bits of 1, 2, 4 bit packed pixel formats */
-   if (transforms & PNG_TRANSFORM_PACKSWAP)
+   if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0)
 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED
       png_set_packswap(png_ptr);
 #else
@@ -1643,7 +1654,7 @@ png_write_png(png_structrp png_ptr, png_inforp info_ptr,
 #endif
 
    /* Invert the alpha channel from opacity to transparency */
-   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+   if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0)
 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
       png_set_invert_alpha(png_ptr);
 #else
@@ -1734,14 +1745,14 @@ png_write_image_16bit(png_voidp argument)
       display->first_row);
    png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row);
    png_uint_16p row_end;
-   const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
+   const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
    int aindex = 0;
    png_uint_32 y = image->height;
 
-   if (image->format & PNG_FORMAT_FLAG_ALPHA)
+   if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
    {
 #     ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
-         if (image->format & PNG_FORMAT_FLAG_AFIRST)
+         if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
          {
             aindex = -1;
             ++input_row; /* To point to the first component */
@@ -1891,15 +1902,15 @@ png_write_image_8bit(png_voidp argument)
       display->first_row);
    png_bytep output_row = png_voidcast(png_bytep, display->local_row);
    png_uint_32 y = image->height;
-   const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) ? 3 : 1;
+   const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1;
 
-   if (image->format & PNG_FORMAT_FLAG_ALPHA)
+   if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0)
    {
       png_bytep row_end;
       int aindex;
 
 #     ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
-         if (image->format & PNG_FORMAT_FLAG_AFIRST)
+         if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0)
          {
             aindex = -1;
             ++input_row; /* To point to the first component */
@@ -1996,7 +2007,7 @@ png_image_set_PLTE(png_image_write_control *display)
 #  endif
 
 #  ifdef PNG_FORMAT_BGR_SUPPORTED
-      const int bgr = (format & PNG_FORMAT_FLAG_BGR) ? 2 : 0;
+      const int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0;
 #  else
 #     define bgr 0
 #  endif
@@ -2013,13 +2024,13 @@ png_image_set_PLTE(png_image_write_control *display)
       /* This gets automatically converted to sRGB with reversal of the
        * pre-multiplication if the color-map has an alpha channel.
        */
-      if (format & PNG_FORMAT_FLAG_LINEAR)
+      if ((format & PNG_FORMAT_FLAG_LINEAR) != 0)
       {
          png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap);
 
          entry += i * channels;
 
-         if (channels & 1) /* no alpha */
+         if ((channels & 1) != 0) /* no alpha */
          {
             if (channels >= 3) /* RGB */
             {
@@ -2131,10 +2142,11 @@ png_image_write_main(png_voidp argument)
    png_inforp info_ptr = image->opaque->info_ptr;
    png_uint_32 format = image->format;
 
-   int colormap = (format & PNG_FORMAT_FLAG_COLORMAP) != 0;
-   int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR) != 0; /* input */
-   int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0;
-   int write_16bit = linear && !colormap && !display->convert_to_8bit;
+   /* The following four ints are actually booleans */
+   int colormap = (format & PNG_FORMAT_FLAG_COLORMAP);
+   int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */
+   int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA);
+   int write_16bit = linear && !colormap && (display->convert_to_8bit == 0);
 
 #  ifdef PNG_BENIGN_ERRORS_SUPPORTED
       /* Make sure we error out on any bad situation */
@@ -2146,7 +2158,7 @@ png_image_write_main(png_voidp argument)
       display->row_stride = PNG_IMAGE_ROW_STRIDE(*image);
 
    /* Set the required transforms then write the rows in the correct order. */
-   if (format & PNG_FORMAT_FLAG_COLORMAP)
+   if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0)
    {
       if (display->colormap != NULL && image->colormap_entries > 0)
       {
@@ -2183,7 +2195,7 @@ png_image_write_main(png_voidp argument)
       /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
       png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
 
-      if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
+      if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
          png_set_cHRM_fixed(png_ptr, info_ptr,
             /* color      x       y */
             /* white */ 31270, 32900,
@@ -2193,7 +2205,7 @@ png_image_write_main(png_voidp argument)
          );
    }
 
-   else if (!(image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB))
+   else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0)
       png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL);
 
    /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit
@@ -2214,23 +2226,23 @@ png_image_write_main(png_voidp argument)
    {
       PNG_CONST png_uint_16 le = 0x0001;
 
-      if (*(png_const_bytep)&le)
+      if ((*(png_const_bytep) & le) != 0)
          png_set_swap(png_ptr);
    }
 
 #  ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED
-      if (format & PNG_FORMAT_FLAG_BGR)
+      if ((format & PNG_FORMAT_FLAG_BGR) != 0)
       {
-         if (!colormap && (format & PNG_FORMAT_FLAG_COLOR) != 0)
+         if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0)
             png_set_bgr(png_ptr);
          format &= ~PNG_FORMAT_FLAG_BGR;
       }
 #  endif
 
 #  ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
-      if (format & PNG_FORMAT_FLAG_AFIRST)
+      if ((format & PNG_FORMAT_FLAG_AFIRST) != 0)
       {
-         if (!colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
+         if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0)
             png_set_swap_alpha(png_ptr);
          format &= ~PNG_FORMAT_FLAG_AFIRST;
       }
@@ -2239,7 +2251,7 @@ png_image_write_main(png_voidp argument)
    /* If there are 16 or fewer color-map entries we wrote a lower bit depth
     * above, but the application data is still byte packed.
     */
-   if (colormap && image->colormap_entries <= 16)
+   if (colormap != 0 && image->colormap_entries <= 16)
       png_set_packing(png_ptr);
 
    /* That should have handled all (both) the transforms. */
@@ -2270,14 +2282,17 @@ png_image_write_main(png_voidp argument)
        * it about 50 times.  The speed-up in pngstest was about 10-20% of the
        * total (user) time on a heavily loaded system.
        */
+#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
       png_set_compression_level(png_ptr, 3);
+#endif
    }
 
    /* Check for the cases that currently require a pre-transform on the row
     * before it is written.  This only applies when the input is 16-bit and
     * either there is an alpha channel or it is converted to 8-bit.
     */
-   if ((linear && alpha) || (!colormap && display->convert_to_8bit))
+   if ((linear != 0 && alpha != 0 ) ||
+       (colormap == 0 && display->convert_to_8bit != 0))
    {
       png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
          png_get_rowbytes(png_ptr, info_ptr)));
@@ -2326,7 +2341,7 @@ png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit,
    {
       if (file != NULL)
       {
-         if (png_image_write_init(image))
+         if (png_image_write_init(image) != 0)
          {
             png_image_write_control display;
             int result;
@@ -2381,7 +2396,7 @@ png_image_write_to_file(png_imagep image, const char *file_name,
          if (fp != NULL)
          {
             if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer,
-               row_stride, colormap))
+               row_stride, colormap) != 0)
             {
                int error; /* from fflush/fclose */
 
@@ -2432,6 +2447,6 @@ png_image_write_to_file(png_imagep image, const char *file_name,
    else
       return 0;
 }
-#endif /* PNG_STDIO_SUPPORTED */
+#endif /* STDIO */
 #endif /* SIMPLIFIED_WRITE */
-#endif /* PNG_WRITE_SUPPORTED */
+#endif /* WRITE */

pngwtran.c

@@ -1,8 +1,8 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.6.9 [February 6, 2014]
- * Copyright (c) 1998-2014 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -177,7 +177,7 @@ png_do_shift(png_row_infop row_info, png_bytep row,
       int shift_start[4], shift_dec[4];
       int channels = 0;
 
-      if (row_info->color_type & PNG_COLOR_MASK_COLOR)
+      if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
       {
          shift_start[channels] = row_info->bit_depth - bit_depth->red;
          shift_dec[channels] = bit_depth->red;
@@ -199,7 +199,7 @@ png_do_shift(png_row_infop row_info, png_bytep row,
          channels++;
       }
 
-      if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+      if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
       {
          shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
          shift_dec[channels] = bit_depth->alpha;
@@ -353,7 +353,7 @@ png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
                *(dp++) = save[1];
             }
          }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
+#endif /* WRITE_16BIT */
       }
 
       else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
@@ -392,7 +392,7 @@ png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
                *(dp++) = save[1];
             }
          }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
+#endif /* WRITE_16BIT */
       }
    }
 }
@@ -422,7 +422,7 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
                *(dp++) = *(sp++);
                */
                sp+=3; dp = sp;
-               *(dp++) = (png_byte)(255 - *(sp++));
+               *dp = (png_byte)(255 - *(sp++));
             }
          }
 
@@ -446,10 +446,10 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
                */
                sp+=6; dp = sp;
                *(dp++) = (png_byte)(255 - *(sp++));
-               *(dp++) = (png_byte)(255 - *(sp++));
+               *dp     = (png_byte)(255 - *(sp++));
             }
          }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
+#endif /* WRITE_16BIT */
       }
 
       else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
@@ -484,10 +484,10 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
                */
                sp+=2; dp = sp;
                *(dp++) = (png_byte)(255 - *(sp++));
-               *(dp++) = (png_byte)(255 - *(sp++));
+               *dp     = (png_byte)(255 - *(sp++));
             }
          }
-#endif /* PNG_WRITE_16BIT_SUPPORTED */
+#endif /* WRITE_16BIT */
       }
    }
 }
@@ -505,7 +505,7 @@ png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
       return;
 
 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
-   if (png_ptr->transformations & PNG_USER_TRANSFORM)
+   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
       if (png_ptr->write_user_transform_fn != NULL)
          (*(png_ptr->write_user_transform_fn)) /* User write transform
                                                  function */
@@ -521,52 +521,54 @@ png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
 #endif
 
 #ifdef PNG_WRITE_FILLER_SUPPORTED
-   if (png_ptr->transformations & PNG_FILLER)
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
       png_do_strip_channel(row_info, png_ptr->row_buf + 1,
          !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
 #endif
 
 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED
-   if (png_ptr->transformations & PNG_PACKSWAP)
+   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
       png_do_packswap(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_WRITE_PACK_SUPPORTED
-   if (png_ptr->transformations & PNG_PACK)
+   if ((png_ptr->transformations & PNG_PACK) != 0)
       png_do_pack(row_info, png_ptr->row_buf + 1,
           (png_uint_32)png_ptr->bit_depth);
 #endif
 
 #ifdef PNG_WRITE_SWAP_SUPPORTED
-   if (png_ptr->transformations & PNG_SWAP_BYTES)
+#  ifdef PNG_16BIT_SUPPORTED
+   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
       png_do_swap(row_info, png_ptr->row_buf + 1);
+#  endif
 #endif
 
 #ifdef PNG_WRITE_SHIFT_SUPPORTED
-   if (png_ptr->transformations & PNG_SHIFT)
+   if ((png_ptr->transformations & PNG_SHIFT) != 0)
       png_do_shift(row_info, png_ptr->row_buf + 1,
           &(png_ptr->shift));
 #endif
 
 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
-   if (png_ptr->transformations & PNG_SWAP_ALPHA)
+   if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
       png_do_write_swap_alpha(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
-   if (png_ptr->transformations & PNG_INVERT_ALPHA)
+   if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
       png_do_write_invert_alpha(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_WRITE_BGR_SUPPORTED
-   if (png_ptr->transformations & PNG_BGR)
+   if ((png_ptr->transformations & PNG_BGR) != 0)
       png_do_bgr(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_WRITE_INVERT_SUPPORTED
-   if (png_ptr->transformations & PNG_INVERT_MONO)
+   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
       png_do_invert(row_info, png_ptr->row_buf + 1);
 #endif
 }
-#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */
-#endif /* PNG_WRITE_SUPPORTED */
+#endif /* WRITE_TRANSFORMS */
+#endif /* WRITE */

projects/vstudio/readme.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.13 - August 21, 2014
+libpng version 1.6.18beta05 - May 31, 2015
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 

projects/vstudio/zlib.props

@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.13 - August 21, 2014
+ * libpng version 1.6.18beta05 - May 31, 2015
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.6.13 - August 21, 2014
+Makefiles for  libpng version 1.6.18beta05 - May 31, 2015
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.13)
+                       (gcc, creates libpng16.so.16.1.6.18beta05)
  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.16.1.6.13)
+                       creates libpng16.so.16.1.6.18beta05)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng16.so.16.1.6.13)
+                       creates libpng16.so.16.1.6.18beta05)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng16.so.16.1.6.13)
+                       creates libpng16.so.16.1.6.18beta05)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile

scripts/def.c

@@ -1,7 +1,7 @@
-/* def.dfn - define format of libpng.def
+/* def.c - define format of libpng.def
  *
- * Last changed in libpng version 1.5.7 [December 15, 2011]
- * Copyright (c) 2010-2011 Glenn Randers-Pehrson
+ * Last changed in libpng version 1.6.16 [December 22, 2014]
+ * Copyright (c) 2011-2014 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -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 1.6.13"
+PNG_DFN ";Version 1.6.18beta05"
 
 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\
         PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"

scripts/dfn.awk

@@ -17,7 +17,7 @@
 BEGIN{
    out="/dev/null"       # as a flag
    out_count=0           # count of output lines
-   err=0                 # set if an error occured
+   err=0                 # set if an error occurred
    sort=0                # sort the output
    array[""]=""
 }

scripts/intprefix.c

@@ -1,8 +1,8 @@
 
-/* intprefix.dfn - generate an unprefixed internal symbol list
+/* intprefix.c - generate an unprefixed internal symbol list
  *
- * Last changed in libpng version 1.6.0 [January 30, 2012]
- * Copyright (c) 2012 Glenn Randers-Pehrson
+ * Last changed in libpng version 1.6.16 [December 22, 2014]
+ * Copyright (c) 2013-2014 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

scripts/libpng-config-head.in

@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.6.13
+version=1.6.18beta05
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@/libpng16
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.6.13
+Version: 1.6.18beta05
 Libs: -L${libdir} -lpng16
 Cflags: -I${includedir}

scripts/makefile.bc32

@@ -52,7 +52,9 @@ LDFLAGS=-L$(ZLIB_DIR) -M $(LDEBUG)
 
 # Pre-built configuration
 # See scripts\pnglibconf.mak for more options
+!ifndef PNGLIBCONF_H_PREBUILT
 PNGLIBCONF_H_PREBUILT = scripts\pnglibconf.h.prebuilt
+!endif
 
 ## Variables
 OBJS = \

scripts/makefile.bor

@@ -60,7 +60,9 @@ LDFLAGS=-M -L$(ZLIB_DIR) $(MODEL_ARG) $(LDEBUG)
 
 # Pre-built configuration
 # See scripts\pnglibconf.mak for more options
+!ifndef PNGLIBCONF_H_PREBUILT
 PNGLIBCONF_H_PREBUILT = scripts\pnglibconf.h.prebuilt
+!endif
 
 ## Variables
 

scripts/makefile.cegcc

@@ -23,7 +23,7 @@
 
 VERMAJ = 1
 VERMIN = 6
-VERMIC = 13
+VERMIC = 18
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)

scripts/makefile.darwin

@@ -36,12 +36,11 @@ LN_SF=ln -sf
 RANLIB=ranlib
 CP=cp
 RM_F=/bin/rm -f
-ARCH=-arch ppc -arch i386 -arch x86_64
 
 CPPFLAGS=-I$(ZLIBINC)
 # CFLAGS=-W -Wall -O3 -funroll-loops
-CFLAGS=-W -Wall -O -funroll-loops $(ARCH)
-LDFLAGS=-L. -L$(ZLIBLIB) -lpng16 -lz $(ARCH)
+CFLAGS=-W -Wall -O -funroll-loops
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng16 -lz
 
 INCPATH=$(prefix)/include
 LIBPATH=$(exec_prefix)/lib
@@ -113,7 +112,7 @@ $(LIBSOMAJ): $(OBJSDLL)
 	$(CC) -dynamiclib \
 	 -install_name $(LIBPATH)/$(LIBSOMAJ) \
 	 -current_version 16 -compatibility_version 16 \
-	 $(ARCH) -o $(LIBSOMAJ) \
+	 -o $(LIBSOMAJ) \
 	 $(OBJSDLL) -L$(ZLIBLIB) -lz
 
 pngtest: pngtest.o $(LIBSO)

scripts/makefile.linux

@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 13
+RELEASE = 18
 
 # Shared library names:
 LIBSO=$(LIBNAME).so

scripts/makefile.msys

@@ -18,7 +18,7 @@ exec_prefix=$(prefix)
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 13
+RELEASE = 18
 
 # Shared library names:
 LIBSO=$(LIBNAME).dll

scripts/makefile.ne12bsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng16
 
 LIB=	png16
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.6.13
+SHLIB_MINOR=	1.6.18beta05
 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

scripts/makefile.netbsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include
 
 LIB=	png
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.13
+SHLIB_MINOR=	1.6.18beta05
 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

scripts/makefile.openbsd

@@ -11,7 +11,7 @@ LIBDIR=	${PREFIX}/lib
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.13
+SHLIB_MINOR=	1.6.18beta05
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \

scripts/makefile.std

@@ -106,7 +106,8 @@ install: libpng.a pnglibconf.h
 	chmod 644 $(DESTDIR)$(LIBPATH)/libpng.a
 
 clean:
-	$(RM_F) *.o libpng.a pngtest pngout.png pnglibconf.*
+	$(RM_F) *.o libpng.a pngtest pngout.png pnglibconf.h pnglibconf.c \
+	pnglibconf.out
 
 DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
 writelock:

scripts/makefile.tc3

@@ -16,7 +16,9 @@ CP=copy
 
 # Pre-built configuration
 # See scripts\pnglibconf.mak for more options
+!ifndef PNGLIBCONF_H_PREBUILT
 PNGLIBCONF_H_PREBUILT = scripts\pnglibconf.h.prebuilt
+!endif
 
 O=.obj
 E=.exe

scripts/makefile.vcwin32

@@ -16,7 +16,7 @@ CC = cl
 LD = link
 AR = lib
 CPPFLAGS = -I..\zlib
-CFLAGS  = -nologo -D_CRT_SECURE_NO_DEPRECATE -MD -O2 -W3
+CFLAGS  = -nologo -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -MD -O2 -W3
 LDFLAGS = -nologo
 ARFLAGS = -nologo
 CP = copy

scripts/options.awk

@@ -1,9 +1,9 @@
 #!/bin/awk -f
 # scripts/options.awk - library build configuration control
 #
-# last changed in libpng version 1.5.7 - December 15, 2011
+# last changed in libpng version 1.6.11 - June 5, 2014
 #
-# Copyright (c) 1998-2011 Glenn Randers-Pehrson
+# Copyright (c) 1998-2014 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer

scripts/pnglibconf.dfa

@@ -8,7 +8,7 @@ com pnglibconf.h - library build configuration
 com
 version
 com
-com Copyright (c) 1998-2012 Glenn Randers-Pehrson
+com Copyright (c) 1998-2014 Glenn Randers-Pehrson
 com
 com This code is released under the libpng license.
 com For conditions of distribution and use, see the disclaimer
@@ -114,6 +114,13 @@ file pnglibconf.h scripts/pnglibconf.dfa PNGLCONF_H
 
 logunsupported = 1
 
+# The following allows the output from configure to modify the contents of
+# pnglibconf.h
+
+@#ifdef HAVE_CONFIG_H
+@#  include "config.h"
+@#endif
+
 # PNG_USER_CONFIG has to be defined on the compiler command line
 # to cause pngusr.h to be read while constructing pnglibconf.h
 #
@@ -189,10 +196,6 @@ setting API_RULE default 0
 
 setting PREFIX
 
-# Default to using the read macros
-
-setting DEFAULT_READ_MACROS default 1
-
 # Implementation specific control of the optimizations, enabled by those
 # hardware or software options that need it (typically when run-time choices
 # must be made by the user)
@@ -218,8 +221,8 @@ option SET_OPTION disabled
 # ARM_NEON_API:   (PNG_ARM_NEON == 1) allow the optimization to be switched on
 #                 with png_set_option
 # ARM_NEON_CHECK: (PNG_ARM_NEON == 1) compile a run-time check to see if Neon
-#                 extensions are supported, this is poorly supported and
-#                 deprectated - use the png_set_option API.
+#                 extensions are supported. This is poorly supported and
+#                 deprecated - use the png_set_option API.
 setting ARM_NEON_OPT
 option ARM_NEON_API disabled requires ALIGNED_MEMORY enables SET_OPTION,
    sets ARM_NEON_OPT 1
@@ -227,19 +230,21 @@ option ARM_NEON_CHECK disabled requires ALIGNED_MEMORY,
    sets ARM_NEON_OPT 1
 
 # These settings configure the default compression level (0-9) and 'strategy';
-# strategy is as defined by the implementors of zlib, it describes the input
+# strategy is as defined by the implementors of zlib. It describes the input
 # data and modifies the zlib parameters in an attempt to optimize the balance
 # between search and huffman encoding in the zlib algorithms.  The defaults are
 # the zlib.h defaults - the apparently recursive definition does not arise
 # because the name of the setting is prefixed by PNG_
 #
 # The TEXT values are the defaults when writing compressed text (all forms)
-#
-# Include the zlib header too, so that the defaults below are known
+
+# Include the zlib header so that the defaults below are known
 @#  include <zlib.h>
 
 # The '@' here means to substitute the value when pnglibconf.h is built
 setting Z_DEFAULT_COMPRESSION default @Z_DEFAULT_COMPRESSION
+# TODO: why aren't these Z_RLE; zlib.h says that Z_RLE, specifically, is
+# appropriate for PNG images, maybe it doesn't exist in all versions?
 setting Z_DEFAULT_STRATEGY default @Z_FILTERED
 setting Z_DEFAULT_NOFILTER_STRATEGY default @Z_DEFAULT_STRATEGY
 setting ZLIB_VERNUM default @ZLIB_VERNUM
@@ -247,6 +252,10 @@ setting ZLIB_VERNUM default @ZLIB_VERNUM
 setting TEXT_Z_DEFAULT_COMPRESSION default @Z_DEFAULT_COMPRESSION
 setting TEXT_Z_DEFAULT_STRATEGY default @Z_DEFAULT_STRATEGY
 
+# Default to using the read macros
+
+setting DEFAULT_READ_MACROS default 1
+
 # The alternative is to call functions to read PNG values, if
 # the functions are turned *off* the read macros must always
 # be enabled, so turning this off will actually force the
@@ -294,7 +303,7 @@ option BENIGN_READ_ERRORS requires BENIGN_ERRORS
 option MNG_FEATURES
 
 # Arithmetic options, the first is the big switch that chooses between internal
-# floating and fixed point arithmetic implementations - it does not affect an
+# floating and fixed point arithmetic implementations - it does not affect any
 # APIs.  The second two (the _POINT settings) switch off individual APIs.
 #
 # Prior to libpng 1.6.8 one of the API (_POINT) variants had to be selected.  At
@@ -341,47 +350,35 @@ option USER_MEM
 
 option IO_STATE
 
-# This is only for PowerPC big-endian and 680x0 systems
-# some testing, not enabled by default.
-# NO LONGER USED
-
-#option READ_BIG_ENDIAN disabled
-
-# Allow users to control limits on what the READ code will
-# read:
-
-# Added at libpng-1.2.43; adds limit fields to png_struct,
-# allows some usages of these fields
-
-option USER_LIMITS
-
-# Added at libpng-1.2.6; adds setting APIs, allows additional
-# usage of this field (UTSL)
-
-option SET_USER_LIMITS requires USER_LIMITS
-
-# Feature added at libpng-1.4.0, this flag added at 1.4.1
-option SET_USER_LIMITS enables SET_CHUNK_CACHE_LIMIT
-# Feature added at libpng-1.4.1, this flag added at 1.4.1
-
-option SET_USER_LIMITS enables SET_CHUNK_MALLOC_LIMIT
-
-# Libpng limits.
+# Libpng limits: limit the size of images and data on read.
 #
-# If these settings are *not* set libpng will not limit the size of
-# images or the size of data in ancilliary chunks.  This does lead to
-# security issues if PNG files come from untrusted sources.
-setting USER_WIDTH_MAX
-setting USER_HEIGHT_MAX
-setting USER_CHUNK_CACHE_MAX
-setting USER_CHUNK_MALLOC_MAX
+# If this option is disabled all the limit checking code will be disabled:
 
-# To default all these settings to values that are large but probably
-# safe turn the SAFE_LIMITS option on; this will cause the value in
-# pngpriv.h to be used.  Individual values can also be set, simply set
-# them in pngusr.dfa with '@#define PNG_setting value' lines.
-option SAFE_LIMITS enables USER_LIMITS disabled
-= SAFE_LIMITS SAFE_LIMITS
+option USER_LIMITS requires READ
+
+# The default settings given below for the limits mean that libpng will
+# limit the size of images or the size of data in ancilliary chunks to less
+# than the specification or implementation limits. Settings have the
+# following interpretations:
+#
+# USER_WIDTH_MAX: maximum width of an image that will be read
+# USER_HEIGHT_MAX: maximum height
+# USER_CHUNK_MALLOC_MAX: maximum in-memory (decompressed) size of a single chunk
+# USER_CHUNK_CACHE_MAX: maximum number of chunks to be cached
+#
+# Only chunks that are variable in number are counted towards the
+
+# Use 0x7fffffff for unlimited
+setting USER_WIDTH_MAX default        1000000
+setting USER_HEIGHT_MAX default       1000000
+
+# Use 0 for unlimited
+setting USER_CHUNK_CACHE_MAX default     1000
+setting USER_CHUNK_MALLOC_MAX default 8000000
+
+# If this option is enabled APIs to set the above limits at run time are added;
+# without this the hardwired (compile time) limits will be used.
+option SET_USER_LIMITS requires USER_LIMITS
 
 # All of the following options relate to code capabilities for
 # processing image data before creating a PNG or after reading one.
@@ -523,6 +520,7 @@ option USER_TRANSFORM_INFO if READ_USER_TRANSFORM, WRITE_USER_TRANSFORM
 # non-IDAT chunks (zTXt, iTXt, iCCP, and unknown chunks).  This feature
 # was added at libpng-1.5.3.
 option WRITE_CUSTOMIZE_ZTXT_COMPRESSION requires WRITE
+option WRITE_CUSTOMIZE_COMPRESSION requires WRITE
 
 # Any chunks you are not interested in, you can undef here.  The
 # ones that allocate memory may be expecially important (hIST,
@@ -648,7 +646,7 @@ setting QUANTIZE_BLUE_BITS default 5
 # are only interested in 8 bits anyway.  Increasing this value
 # results in more memory being used, and more pow() functions
 # being called to fill in the gamma tables.  Don't set this value
-# less then 8, and even that may not work (I haven't tested it).
+# less than 8, and even that may not work (I haven't tested it).
 
 setting MAX_GAMMA_8 default 11
 
@@ -714,7 +712,7 @@ chunk cHRM enables COLORSPACE
 chunk gAMA enables GAMMA
 chunk hIST
 chunk iCCP enables COLORSPACE, GAMMA
-chunk iTXt
+chunk iTXt enables TEXT
 chunk oFFs
 chunk pCAL
 chunk pHYs
@@ -725,7 +723,7 @@ chunk sRGB enables COLORSPACE, GAMMA, SET_OPTION
 chunk tEXt requires TEXT
 chunk tIME
 chunk tRNS
-chunk zTXt
+chunk zTXt enables TEXT
 
 # This only affects support of the optional PLTE chunk in RGB and RGBA
 # images.  Notice that READ_ANCILLARY_CHUNKS therefore disables part
@@ -809,9 +807,9 @@ option SAVE_INT_32 disabled
 option WRITE_OPTIMIZE_CMF requires WRITE
 
 option READ_COMPRESSED_TEXT disabled
+option READ_iCCP enables READ_COMPRESSED_TEXT
 option READ_iTXt enables READ_COMPRESSED_TEXT
 option READ_zTXt enables READ_COMPRESSED_TEXT
-option READ_COMPRESSED_TEXT enables READ_TEXT
 
 option WRITE_oFFs enables SAVE_INT_32
 option WRITE_pCAL enables SAVE_INT_32
@@ -821,7 +819,6 @@ option WRITE_COMPRESSED_TEXT disabled
 option WRITE_iCCP enables WRITE_COMPRESSED_TEXT
 option WRITE_iTXt enables WRITE_COMPRESSED_TEXT
 option WRITE_zTXt enables WRITE_COMPRESSED_TEXT
-option WRITE_COMPRESSED_TEXT enables WRITE_TEXT
 
 # Turn this off to disable png_read_png() and png_write_png() and
 # leave the row_pointers member out of the info structure.

scripts/pnglibconf.h.prebuilt

@@ -1,8 +1,8 @@
-/* libpng 1.6.13 STANDARD API DEFINITION */
+/* libpng 1.6.18beta05 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.13 - August 21, 2014 */
+/* Libpng version 1.6.18beta05 - May 31, 2015 */
 
 /* Copyright (c) 1998-2014 Glenn Randers-Pehrson */
 
@@ -97,13 +97,10 @@
 #define PNG_READ_tIME_SUPPORTED
 #define PNG_READ_tRNS_SUPPORTED
 #define PNG_READ_zTXt_SUPPORTED
-/*#undef PNG_SAFE_LIMITS_SUPPORTED*/
 #define PNG_SAVE_INT_32_SUPPORTED
 #define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SEQUENTIAL_READ_SUPPORTED
 #define PNG_SETJMP_SUPPORTED
-#define PNG_SET_CHUNK_CACHE_LIMIT_SUPPORTED
-#define PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
 #define PNG_SET_OPTION_SUPPORTED
 #define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SET_USER_LIMITS_SUPPORTED
@@ -129,6 +126,7 @@
 #define PNG_WRITE_BGR_SUPPORTED
 #define PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
 #define PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
+#define PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
 #define PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
 #define PNG_WRITE_FILLER_SUPPORTED
 #define PNG_WRITE_FILTER_SUPPORTED
@@ -198,6 +196,10 @@
 #define PNG_QUANTIZE_RED_BITS 5
 #define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
 #define PNG_TEXT_Z_DEFAULT_STRATEGY 0
+#define PNG_USER_CHUNK_CACHE_MAX 1000
+#define PNG_USER_CHUNK_MALLOC_MAX 8000000
+#define PNG_USER_HEIGHT_MAX 1000000
+#define PNG_USER_WIDTH_MAX 1000000
 #define PNG_WEIGHT_SHIFT 8
 #define PNG_ZBUF_SIZE 8192
 #define PNG_ZLIB_VERNUM 0 /* unknown */

scripts/pnglibconf.mak

@@ -49,6 +49,7 @@ pnglibconf.dfn: $(srcdir)/scripts/pnglibconf.dfa $(srcdir)/scripts/options.awk $
 	$(MOVE) pnglibconf.tmp $@
 
 clean-pnglibconf:
-	$(DELETE) pnglibconf.*
+	$(DELETE) pnglibconf.h pnglibconf.c pnglibconf.out pnglibconf.pre \
+	pnglibconf.dfn
 
 clean: clean-pnglibconf

scripts/prefix.c

@@ -1,8 +1,8 @@
 
-/* prefix.dfn - generate an unprefixed symbol list
+/* prefix.c - generate an unprefixed symbol list
  *
- * Last changed in libpng version 1.6.0 [January 30, 2012]
- * Copyright (c) 2012 Glenn Randers-Pehrson
+ * Last changed in libpng version 1.6.16 [December 22, 2014]
+ * Copyright (c) 2013-2014 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

scripts/sym.c

@@ -1,8 +1,8 @@
 
-/* sym.dfn - define format of libpng.sym
+/* sym.c - define format of libpng.sym
  *
- * Last changed in libpng version 1.5.0 [January 6, 2011]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng version 1.6.16 [December 22, 2014]
+ * Copyright (c) 2011-2014 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

scripts/symbols.c

@@ -1,8 +1,8 @@
 
-/* symbols.dfn - find all exported symbols
+/* symbols.c - find all exported symbols
  *
- * Last changed in libpng version 1.5.0 [January 6, 2011]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng version 1.6.16 [December 22, 2014]
+ * Copyright (c) 2011-2014 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

scripts/symbols.def

@@ -1,4 +1,4 @@
-;Version 1.6.13
+;Version 1.6.18beta05
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng

scripts/vers.c

@@ -1,8 +1,8 @@
 
-/* vers.dfn - define format of libpng.vers
+/* vers.c - define format of libpng.vers
  *
- * Last changed in libpng version 1.5.0 [January 6, 2011]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng version 1.6.16 [December 22, 2014]
+ * Copyright (c) 2011-2014 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer