[libpng17] Imported from libpng-1.7.0beta18.tar

filter is found.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.7.0beta09 - April 24, 2013
+Libpng 1.7.0beta18 - September 16, 2013
 
 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.
@@ -9,19 +9,20 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.7.0beta09.tar.xz (LZMA-compressed, recommended)
-   1.7.0beta09.tar.gz
+   1.7.0beta18.tar.xz (LZMA-compressed, recommended)
+   1.7.0beta18.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp170b09.7z  (LZMA-compressed, recommended)
-   lp170b09.zip
+   lp170b18.7z  (LZMA-compressed, recommended)
+   lp170b18.zip
 
 Other information:
 
-   1.7.0beta09-README.txt
-   1.7.0beta09-LICENSE.txt
+   1.7.0beta18-README.txt
+   1.7.0beta18-LICENSE.txt
+   Gnupg/*.asc (PGP armored detached signatures)
 
 Changes since the last public release (1.6.0):
 
@@ -262,6 +263,100 @@ Version 1.7.0beta09 [April 24, 2013]
     Previously the ARM NEON specific files were still built if the option
     was switched 'off' as opposed to being explicitly disabled.
 
+Version 1.7.0beta10 [April 24, 2013]
+  Attempt to fix the PNG_ARM_NEON configuration mess.
+
+Version 1.7.0beta11 [April 26, 2013]
+  Test for 'arm*', not just 'arm' in the host_cpu configure variable.
+
+Version 1.7.0beta12 [April 30, 2013]
+  Added png_app_warning for out-of-range unknown chunk index in
+    png_set_unknown_chunk_location().
+  Expanded manual paragraph about writing private chunks.
+  Avoid dereferencing NULL pointer possibly returned from
+     png_create_write_struct() (Andrew Church).
+
+Version 1.7.0beta13 [May 12, 2013]
+  Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the
+    right zlib header files.
+  Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile
+  Updated contrib/pngminus/pnm2png.c (Paul Stewart):
+    Check for EOF
+    Ignore "#" delimited comments in input file to pnm2png.c.
+    Fixed whitespace handling
+    Added a call to png_set_packing()
+    Initialize dimension values so if sscanf fails at least we have known
+      invalid values.
+  Calculate our own zlib windowBits when decoding rather than trusting the
+    CMF bytes in the PNG datastream.
+  Added an option to force maximum window size for inflating, which was
+    the behavior of libpng15 and earlier.
+  Added png-fix-itxt and png-fix-too-far-back to the built programs and
+    removed warnings from the source code and timepng that are revealed as
+    a result.
+  Detect wrong libpng versions linked to png-fix-too-far-back, which currently
+    only works with libpng versions that can be made to reliably fail when
+    the deflate data contains an out-of-window reference.  This means only
+    1.6 and later.
+  Attempt to detect configuration issues with png-fix-too-far-back, which
+    requires both the correct libpng and the correct zlib to function
+    correctly.
+  Check ZLIB_VERNUM for mismatches, enclose #error in quotes
+  Added information in the documentation about problems with and fixes for
+    the bad CRC and bad iTXt chunk situations.
+
+Version 1.7.0beta14 [June 8, 2013]
+  Removed a redundant test in png_set_IHDR().
+  Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt)
+  Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt
+  Enclose the prototypes for the simplified write API in #ifdef STDIO/#endif
+  Make ARM NEON support work at compile time (not just configure time).
+    This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
+    using a compiler that compiles for multiple architectures at one time.
+  Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from
+    pnglibconf.h, allowing more of the decisions to be made internally
+    (pngpriv.h) during the compile.  Without this, symbol prefixing is broken
+    under certain circumstances on ARM platforms.  Now only the API parts of
+    the optimizations ('check' vs 'api') are exposed in the public header files
+    except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
+    decision about whether or not to use the optimizations.
+  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS useage.
+    Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
+    on __ARM_NEON__ from configure time to compile time.  This breaks symbol
+    prefixing because the definition of the special png_init_filter_functions
+    call was hidden at configure time if the relevant compiler arguments are
+    passed in CFLAGS as opposed to CC.  This change attempts to avoid all
+    the confusion that would result by declaring the init function even when
+    it is not used, so that it will always get prefixed.
+
+Version 1.7.0beta15 [June 18, 2013]
+  Revised libpng.3 so that "doclifter" can process it.
+
+Version 1.7.0beta16 [July 5, 2013]
+  Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18
+    as parameters for png_set_gamma().  These have been available since
+    libpng-1.5.4.
+  Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it
+    to check all compressed chunks known to libpng.
+  Updated documentation to show default behavior of benign errors correctly.
+  Added perfect hash code generation for lists of PNG chunks. This is
+    a work in progress; checked in for use in pngfix.c
+  Ported ARM no-read patch from libpng16.
+  Ported pngfix.c patches from libpng16.
+
+Version 1.7.0beta17 [August 21, 2013]
+  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
+  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
+    may be erroneously issued by code-checking applications.
+  Added information about png_set_options() to the manual.
+  Delay calling png_init_filter_functions() until a row with nonzero filter
+    is found.
+
+Version 1.7.0beta18 [September 16, 2013]
+  Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
+    prototype, definition, and usage.  Made it depend on
+    PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CHANGES

@@ -4046,7 +4046,9 @@ Version 1.6.0beta17 [March 10, 2012]
   Deflate/inflate was reworked to move common zlib calls into single
     functions [rw]util.c.  A new shared keyword check routine was also added
     and the 'zbuf' is no longer allocated on progressive read.  It is now
-    possible to call png_inflate() incrementally.
+    possible to call png_inflate() incrementally.  A warning is no longer
+    issued if the language tag or translated keyword in the iTXt chunk
+    has zero length.
   If benign errors are disabled use maximum window on ancilliary inflate.
     This works round a bug introduced in 1.5.4 where compressed ancillary
     chunks could end up with a too-small windowBits value in the deflate
@@ -4545,11 +4547,105 @@ Version 1.7.0beta09 [April 24, 2013]
   Exposed PNG chunk types in png.h
   Modified png_uint_32 macros/code to make as few assumptions as possible
     about the hardware.
-  Revised stack marking in arm/filter_neon.S and configure.ac
+  Revised stack marking in arm/filter_neon.S and configure.ac.
   Ensure that NEON filter stuff is completely disabled when switched 'off'.
     Previously the ARM NEON specific files were still built if the option
     was switched 'off' as opposed to being explicitly disabled.
 
+Version 1.7.0beta10 [April 24, 2013]
+  Attempt to fix the PNG_ARM_NEON configuration mess.
+
+Version 1.7.0beta11 [April 26, 2013]
+  Test for 'arm*', not just 'arm' in the host_cpu configure variable.
+
+Version 1.7.0beta12 [April 30, 2013]
+  Added png_app_warning for out-of-range unknown chunk index in
+    png_set_unknown_chunk_location().
+  Expanded manual paragraph about writing private chunks.
+  Avoid dereferencing NULL pointer possibly returned from
+     png_create_write_struct() (Andrew Church).
+
+Version 1.7.0beta13 [May 12, 2013]
+  Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the
+    right zlib header files.
+  Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile
+  Updated contrib/pngminus/pnm2png.c (Paul Stewart):
+    Check for EOF
+    Ignore "#" delimited comments in input file to pnm2png.c.
+    Fixed whitespace handling
+    Added a call to png_set_packing()
+    Initialize dimension values so if sscanf fails at least we have known
+      invalid values.
+  Calculate our own zlib windowBits when decoding rather than trusting the
+    CMF bytes in the PNG datastream.
+  Added an option to force maximum window size for inflating, which was
+    the behavior of libpng15 and earlier.
+  Added png-fix-itxt and png-fix-too-far-back to the built programs and
+    removed warnings from the source code and timepng that are revealed as
+    a result.
+  Detect wrong libpng versions linked to png-fix-too-far-back, which currently
+    only works with libpng versions that can be made to reliably fail when
+    the deflate data contains an out-of-window reference.  This means only
+    1.6 and later.
+  Attempt to detect configuration issues with png-fix-too-far-back, which
+    requires both the correct libpng and the correct zlib to function
+    correctly.
+  Check ZLIB_VERNUM for mismatches, enclose #error in quotes
+  Added information in the documentation about problems with and fixes for
+    the bad CRC and bad iTXt chunk situations.
+
+Version 1.7.0beta14 [June 8, 2013]
+  Removed a redundant test in png_set_IHDR().
+  Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt)
+  Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt
+  Enclose the prototypes for the simplified write API in #ifdef STDIO/#endif
+  Make ARM NEON support work at compile time (not just configure time).
+    This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
+    using a compiler that compiles for multiple architectures at one time.
+  Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from
+    pnglibconf.h, allowing more of the decisions to be made internally
+    (pngpriv.h) during the compile.  Without this, symbol prefixing is broken
+    under certain circumstances on ARM platforms.  Now only the API parts of
+    the optimizations ('check' vs 'api') are exposed in the public header files
+    except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
+    decision about whether or not to use the optimizations.
+  Protect symbol prefixing against CC/CPPFLAGS/CFLAGS useage.
+    Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
+    on __ARM_NEON__ from configure time to compile time.  This breaks symbol
+    prefixing because the definition of the special png_init_filter_functions
+    call was hidden at configure time if the relevant compiler arguments are
+    passed in CFLAGS as opposed to CC.  This change attempts to avoid all
+    the confusion that would result by declaring the init function even when
+    it is not used, so that it will always get prefixed.
+
+Version 1.7.0beta15 [June 18, 2013]
+  Revised libpng.3 so that "doclifter" can process it.
+
+Version 1.7.0beta16 [July 5, 2013]
+  Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18
+    as parameters for png_set_gamma().  These have been available since
+    libpng-1.5.4.
+  Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it
+    to check all compressed chunks known to libpng.
+  Updated documentation to show default behavior of benign errors correctly.
+  Added perfect hash code generation for lists of PNG chunks. This is
+    a work in progress; checked in for use in pngfix.c
+  Ported ARM no-read patch from libpng16.
+  Ported pngfix.c patches from libpng16.
+
+Version 1.7.0beta17 [August 21, 2013]
+  Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
+  Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
+    may be erroneously issued by code-checking applications.
+  Added information about png_set_options() to the manual.
+  Delay calling png_init_filter_functions() until a row with nonzero filter
+    is found.
+
+Version 1.7.0beta18 [September 16, 2013]
+  Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
+    prototype, definition, and usage.  Made it depend on
+    PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement

CMakeLists.txt

@@ -1,6 +1,6 @@
 # CMakeLists.txt
 
-# Copyright (C) 2007-2011 Glenn Randers-Pehrson
+# Copyright (C) 2007-2013 Glenn Randers-Pehrson
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -9,26 +9,7 @@
 cmake_minimum_required(VERSION 2.4.4)
 set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true)
 
-if(UNIX AND NOT DEFINED CMAKE_BUILD_TYPE)
-  if(CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION EQUAL 4)
-    # workaround CMake 2.4.x bug
-    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
-        "Choose the type of build, options are:
-           None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used)
-           Debug
-           Release
-           RelWithDebInfo
-           MinSizeRel.")
-  else()
-    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
-        "Choose the type of build, options are:
-           None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used)
-           Debug
-           Release
-           RelWithDebInfo
-           MinSizeRel.")
-  endif()
-endif()
+set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
 
 project(libpng C)
 enable_testing()
@@ -271,7 +252,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 17.${PNGLIB_RELEASE}.1.7.0beta09
+#   VERSION 17.${PNGLIB_RELEASE}.1.7.0beta18
     VERSION 17.${PNGLIB_RELEASE}.0
     SOVERSION 17
     CLEAN_DIRECT_OUTPUT 1)

LICENSE

@@ -10,7 +10,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.7.0beta09, April 18, 2013, are
+libpng versions 1.2.6, August 15, 2004, through 1.7.0beta18, September 16, 2013, are
 Copyright (c) 2004, 2006-2013 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
-April 18, 2013
+September 16, 2013

Makefile.am

@@ -9,6 +9,9 @@ ACLOCAL_AMFLAGS = -I scripts
 # test programs - run on make check, make distcheck
 check_PROGRAMS= pngtest pngunknown pngstest pngvalid
 
+# Utilities - installed
+bin_PROGRAMS= pngfix png-fix-itxt
+
 pngtest_SOURCES = pngtest.c
 pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
@@ -21,6 +24,11 @@ pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 pngunknown_SOURCES = contrib/libtests/pngunknown.c
 pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
+pngfix_SOURCES = contrib/tools/pngfix.c
+pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
+
 # Generally these are single line shell scripts to run a test with a particular
 # set of parameters:
 TESTS =\
@@ -182,14 +190,15 @@ endif
 $(srcdir)/scripts/pnglibconf.h.prebuilt:
 	@echo "Attempting to build $@" >&2
 	@echo "This is a machine generated file, but if you want to make" >&2
-	@echo "a new one simply make 'scripts/pnglibconf.out' and copy that" >&2
+	@echo "a new one simply make 'scripts/pnglibconf.out', copy that" >&2
+	@echo "AND set PNG_ZLIB_VERNUM to 0 (you MUST do this)" >&2
 	@exit 1
 
 # The following is necessary to ensure that the local pnglibconf.h is used, not
 # an installed one (this can happen immediately after on a clean system if
 # 'make test' is the first thing the user does.)
-contrib/libtests/pngstest.o contrib/libtests/pngvalid.o pngtest.o: pnglibconf.h
-contrib/libtests/pngunknown.o: pnglibconf.h
+pngstest.o pngvalid.o pngtest.o pngunknown.o timepng.o: pnglibconf.h
+pngfix.o png-fix-itxt.o: pnglibconf.h
 
 # We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
 # be built with PNG_USE_READ_MACROS; this prevents the read macros from

README

@@ -1,11 +1,11 @@
-README for libpng version 1.7.0beta09 - April 18, 2013 (shared library 17.0)
+README for libpng version 1.7.0beta18 - September 16, 2013 (shared library 17.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
 
-Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
-libpng-*.tar.xz or libpng-*.tar.bz2 if you want UNIX-style line endings
-in the text files, or lpng*.zip if you want DOS-style line endings.
+Libpng comes in several distribution formats.  Get libpng-*.tar.gz or
+libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
+or lpng*.7z or lpng*.zip if you want DOS-style line endings.
 
 Version 0.89 was the first official release of libpng.  Don't let the
 fact that it's the first release fool you.  The libpng library has been in
@@ -77,17 +77,15 @@ compression library that is useful for more things than just PNG files.
 You can use zlib as a drop-in replacement for fread() and fwrite() if
 you are so inclined.
 
-zlib should be available at the same place that libpng is, or at.
-ftp://ftp.info-zip.org/pub/infozip/zlib
+zlib should be available at the same place that libpng is, or at zlib.net.
 
 You may also want a copy of the PNG specification.  It is available
 as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
 these at http://www.libpng.org/pub/png/documents/
 
 This code is currently being archived at libpng.sf.net in the
-[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
-at GO GRAPHSUP.  If you can't find it in any of those places,
-e-mail me, and I'll help you find it.
+[DOWNLOAD] area, and at ftp://ftp.simplesystems.org.  If you can't find it
+in any of those places, e-mail me, and I'll help you find it.
 
 If you have any code changes, requests, problems, etc., please e-mail
 them to me.  Also, I'd appreciate any make files or project files,
@@ -123,7 +121,7 @@ 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 sixteen years now, and it is official and
+been discussing PNG for eighteen 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.
@@ -167,23 +165,25 @@ Files in this distribution:
       pngwrite.c    =>  High-level write functions
       pngwtran.c    =>  Write data transformations
       pngwutil.c    =>  Write utility functions
+      arm           =>  Contains optimized code for the ARM platform
       contrib       =>  Contributions
+       examples         =>  Example programs
        gregbook         =>  source code for PNG reading and writing, from
                             Greg Roelofs' "PNG: The Definitive Guide",
                             O'Reilly, 1999
-       msvctest     =>  Builds and runs pngtest using a MSVC workspace
-       pngminus     =>  Simple pnm2png and png2pnm programs
-       pngsuite     =>  Test images
+       libtests         =>  Test programs
+       pngminim         =>  Minimal decoder, encoder, and progressive decoder
+                            programs demonstrating use of pngusr.dfa
+       pngminus         =>  Simple pnm2png and png2pnm programs
+       pngsuite         =>  Test images
+       tools            =>  Various tools
        visupng      =>  Contains a MSVC workspace for VisualPng
       projects      =>  Contains project files and workspaces for
                         building a DLL
-       cbuilder5        =>  Contains a Borland workspace for building
-                            libpng and zlib
-       visualc6         =>  Contains a Microsoft Visual C++ (MSVC)
-                            workspace for building libpng and zlib
+       owatcom          =>  Contains a WATCOM project for building libpng
        visualc71        =>  Contains a Microsoft Visual C++ (MSVC)
                             workspace for building libpng and zlib
-       xcode            =>  Contains an Apple xcode
+       vstudio          =>  Contains a Microsoft Visual C++ (MSVC)
                             workspace for building libpng and zlib
       scripts       =>  Directory containing scripts for building libpng:
                             (see scripts/README.txt for the list of scripts)

arm/arm_init.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.5.15 [March 28, 2013]
+ * Last changed in libpng 1.6.6 [September 16, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -16,7 +16,8 @@
 
 #include "../pngpriv.h"
 
-#ifdef PNG_ARM_NEON_SUPPORTED
+#ifdef PNG_READ_SUPPORTED
+#if PNG_ARM_NEON_OPT > 0
 #ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
 #include <signal.h> /* for sig_atomic_t */
 
@@ -216,4 +217,5 @@ png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
           png_read_filter_row_paeth4_neon;
    }
 }
-#endif /* FILTER_OPTIMIZATIONS && __arm__ && __ARM_NEON__ */
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_READ_SUPPORTED */

arm/filter_neon.S

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.2 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.17 [July 18, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -11,7 +11,7 @@
  */
 
 /* This is required to get the symbol renames, which are #defines, and also
- * includes the value of PNG_FILTER_OPTIMIZATIONS.
+ * includes the definition (or not) of PNG_ARM_NEON_OPT.
  */
 #define PNG_VERSION_INFO_ONLY
 #include "../pngpriv.h"
@@ -20,8 +20,8 @@
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
 
-#if defined(PNG_FILTER_OPTIMIZATIONS) && defined(__arm__) && \
-   defined(__ARM_NEON__)
+#ifdef PNG_READ_SUPPORTED
+#if PNG_ARM_NEON_OPT > 0
 
 #ifdef __ELF__
 #   define ELF
@@ -233,4 +233,5 @@ func    png_read_filter_row_paeth3_neon, export=1
 
         pop             {r4,pc}
 endfunc
-#endif /* FILTER_OPTIMIZATIONS && __arm__ && __ARM_NEON__ */
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_READ_SUPPORTED */

configure.ac

@@ -18,7 +18,7 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.7.0beta09],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.7.0beta18],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -39,7 +39,7 @@ 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=1.7.0beta09
+PNGLIB_VERSION=1.7.0beta18
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=7
 PNGLIB_RELEASE=0
@@ -334,19 +334,27 @@ AC_ARG_WITH(libpng-prefix,
     fi])
 AM_CONDITIONAL([DO_PNG_PREFIX], [test "${with_libpng_prefix:-no}" != "no"])
 
+# HOST SPECIFIC OPTIONS
+# =====================
+#
+# ARM
+# ===
+#
+# ARM NEON (SIMD) support.
+
 AC_ARG_ENABLE([arm-neon],
    AS_HELP_STRING([[[--enable-arm-neon]]],
-      [Enable ARM NEON optimizations: =off, check, api, on:]
-      [off: disable the optimizations; check: use internal checking code]
+      [Enable ARM NEON optimizations: =no/off, check, api, yes/on:]
+      [no/off: disable the optimizations; check: use internal checking code]
       [(deprecated and poorly supported); api: disable by default, enable by]
-      [a call to png_set_option; on: turn on unconditionally.  The]
-      [default is 'on' if __ARM_NEON__ is defined, otherwise 'off'.]),
+      [a call to png_set_option; yes/on: turn on unconditionally.]
+      [If not specified: determined by the compiler.]),
    [case "$enableval" in
       no|off)
          # disable the default enabling on __ARM_NEON__ systems:
-         AC_DEFINE([PNG_NO_ARM_NEON], [],
+         AC_DEFINE([PNG_ARM_NEON_OPT], [0],
                    [Disable ARM Neon optimizations])
-         # Prevent use of the assembler files below:
+         # Prevent inclusion of the assembler files below:
          enable_arm_neon=no;;
       check)
          AC_DEFINE([PNG_ARM_NEON_CHECK_SUPPORTED], [],
@@ -354,13 +362,26 @@ AC_ARG_ENABLE([arm-neon],
       api)
          AC_DEFINE([PNG_ARM_NEON_API_SUPPORTED], [],
                    [Turn on ARM Neon optimizations at run-time]);;
-      on)
-         AC_DEFINE([PNG_ARM_NEON_SUPPORTED], [],
-                   [Enable ARM Neon optimizations]);;
+      yes|on)
+         AC_DEFINE([PNG_ARM_NEON_OPT], [2],
+                   [Enable ARM Neon optimizations])
+         AC_MSG_WARN([--enable-arm-neon: please specify 'check' or 'api', if]
+            [you want the optimizations unconditionally pass -mfpu=neon]
+            [to the compiler.]);;
       *)
-         AC_MSG_ERROR([arm-neon: option value required (off/check/api/on)]);;
+         AC_MSG_ERROR([--enable-arm-neon=${enable_arm_neon}: invalid value])
    esac])
-AM_CONDITIONAL([PNG_ARM_NEON], [test "${enable_arm_neon:-no}" != "no"])
+
+# Add ARM specific files to all builds where the host_cpu is arm ('arm*') or
+# where ARM optimizations were explicitly requested (this allows a fallback if a
+# future host CPU does not match 'arm*')
+
+AM_CONDITIONAL([PNG_ARM_NEON],
+   [test "$enable_arm_neon" != 'no' &&
+    case "$host_cpu" in
+      arm*) :;;
+      *)    test "$enable_arm_neon" != '';;
+    esac])
 
 AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
 

contrib/libtests/pngunknown.c

@@ -1,8 +1,8 @@
 
 /* pngunknown.c - test the read side unknown chunk handling
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
  * This code is released under the libpng license.
@@ -75,7 +75,7 @@ typedef png_byte *png_const_bytep;
 #  define png_const_structp png_structp
 #endif
 
-/* Types of chunks not know to libpng */
+/* Types of chunks not known to libpng */
 #define png_vpAg PNG_U32(118, 112, 65, 103)
 
 /* Chunk information */

contrib/libtests/readpng.c

@@ -2,7 +2,7 @@
  *
  * Copyright (c) 2013 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+ * 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

contrib/pngminim/decoder/makefile

@@ -14,7 +14,8 @@ LD=$(CC)
 RM=rm -f
 COPY=cp
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP -I. -O1
+CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1
 
 C=.c
 O=.o
@@ -81,7 +82,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 
 # note: dependencies do not work on implicit rule lines
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) $(CPPFLAGS) -c $(CFLAGS) $<
 
 # dependencies
 
@@ -95,12 +96,12 @@ pngm2pnm$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
 	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:

contrib/pngminim/encoder/makefile

@@ -14,7 +14,8 @@ LD=$(CC)
 RM=rm -f
 COPY=cp
 
-CFLAGS=-DPNG_USER_CONFIG -DZ_SOLO -DNO_GZIP -I. -O1
+CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1
 
 C=.c
 O=.o
@@ -80,7 +81,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) $(CPPFLAGS) -c $(CFLAGS) $<
 
 # dependencies
 
@@ -94,12 +95,12 @@ pnm2pngm$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
 	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:

contrib/pngminim/preader/makefile

@@ -30,7 +30,8 @@ XLIB = -L/usr/X11R6/lib -lX11
 #LIBS = $(XLIB)
 LIBS = $(XLIB) -lm                      #platforms that need libm
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP -I. $(XINC) -O1
+CPPFLAGS=-I. $(XINC) -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1
 
 C=.c
 O=.o
@@ -96,7 +97,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) $(CPPFLAGS) -c $(CFLAGS) $<
 
 # dependencies
 
@@ -110,12 +111,12 @@ rpng2-x$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
 	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:

contrib/pngminus/pnm2png.c

@@ -198,9 +198,9 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   char          height_token[16];
   char          maxval_token[16];
   int           color_type;
-  unsigned long   ul_width, ul_alpha_width;
-  unsigned long   ul_height, ul_alpha_height;
-  unsigned long   ul_maxval;
+  unsigned long   ul_width=0, ul_alpha_width=0;
+  unsigned long   ul_height=0, ul_alpha_height=0;
+  unsigned long   ul_maxval=0;
   png_uint_32   width, alpha_width;
   png_uint_32   height, alpha_height;
   png_uint_32   maxval;
@@ -210,6 +210,9 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   int           alpha_present;
   int           row, col;
   BOOL          raw, alpha_raw = FALSE;
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  BOOL          packed_bitmap = FALSE;
+#endif
   png_uint_32   tmp16;
   int           i;
 
@@ -222,9 +225,21 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   }
   else if ((type_token[1] == '1') || (type_token[1] == '4'))
   {
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
     raw = (type_token[1] == '4');
     color_type = PNG_COLOR_TYPE_GRAY;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &ul_width);
+    width = (png_uint_32) ul_width;
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &ul_height);
+    height = (png_uint_32) ul_height;
     bit_depth = 1;
+    packed_bitmap = TRUE;
+#else
+    fprintf (stderr, "PNM2PNG built without PNG_WRITE_INVERT_SUPPORTED and \n");
+    fprintf (stderr, "PNG_WRITE_PACK_SUPPORTED can't read PBM (P1,P4) files\n");
+#endif
   }
   else if ((type_token[1] == '2') || (type_token[1] == '5'))
   {
@@ -343,8 +358,14 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 
   alpha_present = (channels - 1) % 2;
 
-  /* row_bytes is the width x number of channels x (bit-depth / 8) */
-  row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  if (packed_bitmap)
+    /* row data is as many bytes as can fit width x channels x bit_depth */
+    row_bytes = (width * channels * bit_depth + 7) / 8;
+  else
+#endif
+    /* row_bytes is the width x number of channels x (bit-depth / 8) */
+    row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
 
   if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
     return FALSE;
@@ -354,40 +375,48 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 
   for (row = 0; row < height; row++)
   {
-    for (col = 0; col < width; col++)
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+    if (packed_bitmap) {
+      for (i = 0; i < row_bytes; i++)
+        /* png supports this format natively so no conversion is needed */
+        *pix_ptr++ = get_data (pnm_file, 8);
+    } else
+#endif
     {
-      for (i = 0; i < (channels - alpha_present); i++)
+      for (col = 0; col < width; col++)
       {
-        if (raw)
-          *pix_ptr++ = get_data (pnm_file, bit_depth);
-        else
-          if (bit_depth <= 8)
-            *pix_ptr++ = get_value (pnm_file, bit_depth);
+        for (i = 0; i < (channels - alpha_present); i++)
+        {
+          if (raw)
+            *pix_ptr++ = get_data (pnm_file, bit_depth);
           else
-          {
-            tmp16 = get_value (pnm_file, bit_depth);
-            *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
-            pix_ptr++;
-            *pix_ptr = (png_byte) (tmp16 & 0xFF);
-            pix_ptr++;
-          }
-      }
+            if (bit_depth <= 8)
+              *pix_ptr++ = get_value (pnm_file, bit_depth);
+            else
+            {
+              tmp16 = get_value (pnm_file, bit_depth);
+              *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
+              pix_ptr++;
+              *pix_ptr = (png_byte) (tmp16 & 0xFF);
+              pix_ptr++;
+            }
+        }
 
-      if (alpha) /* read alpha-channel from pgm file */
-      {
-        if (alpha_raw)
-          *pix_ptr++ = get_data (alpha_file, alpha_depth);
-        else
-          if (alpha_depth <= 8)
-            *pix_ptr++ = get_value (alpha_file, bit_depth);
+        if (alpha) /* read alpha-channel from pgm file */
+        {
+          if (alpha_raw)
+            *pix_ptr++ = get_data (alpha_file, alpha_depth);
           else
-          {
-            tmp16 = get_value (alpha_file, bit_depth);
-            *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
-            *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
-          }
-      } /* if alpha */
-
+            if (alpha_depth <= 8)
+              *pix_ptr++ = get_value (alpha_file, bit_depth);
+            else
+            {
+              tmp16 = get_value (alpha_file, bit_depth);
+              *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
+              *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
+            }
+        } /* if alpha */
+      } /* if packed_bitmap */
     } /* end for col */
   } /* end for row */
 
@@ -404,6 +433,14 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
     return FALSE;
   }
 
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  if (packed_bitmap == TRUE)
+  {
+    png_set_packing (png_ptr);
+    png_set_invert_mono (png_ptr);
+  }
+#endif
+
   /* setjmp() must be called in every function that calls a PNG-reading libpng function */
   if (setjmp (png_jmpbuf(png_ptr)))
   {
@@ -460,19 +497,32 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 void get_token(FILE *pnm_file, char *token)
 {
   int i = 0;
+  int ret;
 
-  /* remove white-space */
+  /* remove white-space and comment lines */
   do
   {
-    token[i] = (unsigned char) fgetc (pnm_file);
+    ret = fgetc(pnm_file);
+    if (ret == '#') {
+      /* the rest of this line is a comment */
+      do
+      {
+        ret = fgetc(pnm_file);
+      }
+      while ((ret != '\n') && (ret != '\r') && (ret != EOF));
+    }
+    if (ret == EOF) break;
+    token[i] = (unsigned char) ret;
   }
   while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
 
   /* read string */
   do
   {
+    ret = fgetc(pnm_file);
+    if (ret == EOF) break;
     i++;
-    token[i] = (unsigned char) fgetc (pnm_file);
+    token[i] = (unsigned char) ret;
   }
   while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
 

contrib/tools/chunkhash.c

@@ -0,0 +1,437 @@
+/* chunkhash.c -- build a perfect hash code for the chunk names on stdin.
+ *
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2013.
+ * 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.
+ *
+ * Feed this program all the known chunks that libpng must recognize.  It will
+ * generate an appropriate hash key for the macro in pngpriv.h  To generate the
+ * list of chunks currently defined in png.h do this:
+ *
+ *    sed -n -e 's/^#define png_\(....\) PNG_U32.*$/\1/p' png.h
+ *
+ * An alternative to using this program is to pipe the output of the above
+ * through gperf, however the code generated by perf is somewhat more verbose
+ * and it doesn't generate as good a result (however it's a heck of a lot faster
+ * than this program!)
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <png.h> /* for the libpng types for this platform */
+
+/* The machine generated file is checked in, so this works and it obtains the
+ * definition of the PNG_CHUNK_HASH macro.  To change this definition only ever
+ * alter the strings below!
+ */
+#include "chunkhash.h"
+
+/* The best_ variables are local variables defined in the functions below.  When
+ * used in libpng code, however, they are just constants.
+ */
+#define PNG_CHUNK_HASH_MASK best_mask
+#define PNG_CHUNK_HASH_C0 best_c[0]
+#define PNG_CHUNK_HASH_C1 best_c[1]
+#define PNG_CHUNK_HASH_C2 best_c[2]
+#define PNG_CHUNK_HASH_C3 best_c[3]
+
+/* These strings contain the C text to copy into the new version of
+ * contrib/tools/chunkhash.c
+ */
+static const char *strings[] = {
+"/* chunkhash.h -- a perfect hash code for the chunk names in png.h",
+" *",
+" * Last changed in libpng 1.7.0 [(PENDING RELEASE)]",
+" *",
+" * THIS IS A MACHINE GENERATED FILE.  See contrib/tools/chunkhash.c for",
+" * copyright and other information.",
+" *",
+" * USAGE:  To include the PNG_CHUNK_HASH macro and associated definitions:",
+" *",
+" * #define PNG_CHUNKHASH_DEFS",
+" * #include \"contrib/tools/chunkhash.h\"",
+" *",
+" * To define the png_chunk_hash array used by the macro:",
+" *",
+" * #define PNG_CHUNKHASH_CODE",
+" * #include \"contrib/tools/chunkhash.h\"",
+" *",
+" * One or both of the defines must be given except when building chunkhash",
+" * itself.",
+" */",
+"#ifdef PNG_CHUNKHASH_DEFS",
+"#ifndef PNG_CHUNKHASH_H",
+"#define PNG_CHUNKHASH_H",
+"/* A perfect hash code - returns a value 0..(PNG_KNOWN_CHUNK_COUNT-1) and is",
+" * generated by the ridiculously simple program in contrib/tools/chunkhash.c",
+" *",
+" * The hash code used here multiplies each byte by a different constant to",
+" * return a single number:",
+" *",
+" *    b0 * c[0] + b1 * [c1] + b2 * c[2] + b3 * c[3]",
+" *",
+" * The values of the constants are found by search using the a table of",
+" * primes, including 0, and may be (in fact are at present) 0 for some of the",
+" * bytes, the compiler is expected to optimize multiply by zero, or one!",
+" *",
+" * The lookup table reduces the sparse result of the hash calculation to the",
+" * correct index values.  The chunks are indexed in the string order of the",
+" * png_uint_32 chunk names.",
+" */",
+0, /* HEADER definitions go here */
+"",
+"extern const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1];",
+"#endif /* !PNG_CHUNKHASH_H */",
+"#endif /* PNG_CHUNKHASH_DEFS */",
+"",
+"#ifndef PNG_CHUNK_HASH",
+"#define PNG_CHUNK_HASH(chunk) (png_chunk_hash[PNG_CHUNK_HASH_MASK & (\\",
+"      ((chunk) >> 24) * PNG_CHUNK_HASH_C0 +\\",
+"      ((chunk) >> 16) * PNG_CHUNK_HASH_C1 +\\",
+"      ((chunk) >>  8) * PNG_CHUNK_HASH_C2 +\\",
+"      ((chunk)      ) * PNG_CHUNK_HASH_C3)])",
+"#endif",
+"",
+"#ifdef PNG_CHUNKHASH_CODE",
+"#ifndef PNG_CHUNKHASH_C",
+"#define PNG_CHUNKHASH_C",
+"const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1] = {",
+0, /* png.c definitions go here */
+"};",
+"#endif /* !PNG_CHUNKHASH_C */",
+"#endif /* PNG_CHUNKHASH_CODE */",
+0 /* end of file */
+};
+
+#define CHUNK_COUNT_MAX 32
+   /* If necessary this is easy to increase; just don't use a png_uint_32
+    * bitmask below, however it doesn't seem likely that the limit will be hit
+    * any time soon.
+    */
+
+static const png_byte
+chunk_hash[256] =
+{
+   0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
+   22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+   41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
+   60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,
+   79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97,
+   98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113,
+   114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128,
+   129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
+   144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158,
+   159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173,
+   174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188,
+   189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203,
+   204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218,
+   219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233,
+   234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248,
+   249, 250, 251, 252, 253, 254, 255
+};
+
+static void
+error(const char *string)
+{
+   fprintf(stderr, "chunkhash: %s\n", string);
+   exit(1);
+}
+
+/* Return a hash code for the given chunk; this is the same as the pngpriv.h
+ * macro, but parameterized.  The names of the parameters have to be chosen to
+ * match the above #defines.
+ */
+static png_uint_32
+test_hash(png_uint_32 chunk, const unsigned int *best_c, png_uint_32 best_mask)
+{
+#  define png_chunk_hash chunk_hash /* prevents lookup */
+      return PNG_CHUNK_HASH(chunk);
+#  undef png_chunk_hash
+}
+
+static void
+print_chunks(const png_uint_32 *chunks, unsigned int nchunks, png_uint_32 first,
+   png_uint_32 last, const unsigned int *best_c, png_uint_32 best_mask,
+   const png_byte *lut)
+{
+   /* 'last' is the last code to print plus 1, this is used to detect duplicates
+    * (which should not happen - if there are any it's an internal error!)
+    */
+   if (nchunks > 0)
+   {
+      /* Recursive algorithm; find the hash code of the next chunk, then print
+       * all remaining chunks with codes in the range first..code (including
+       * duplicates) and after print all remaining chunks with codes in the
+       * range (code+1)..last
+       */
+      const png_uint_32 chunk = *chunks++;
+#     define png_chunk_hash lut
+         const png_uint_32 code = PNG_CHUNK_HASH(chunk);
+#     undef png_chunk_hash
+
+      --nchunks;
+
+      /* The code might be out of the print range */
+      if (code >= first && code <= last)
+      {
+         if (code >= first) /* not time yet */
+            print_chunks(chunks, nchunks, first, code, best_c, best_mask, lut);
+
+         printf("#define PNG_CHUNK_%c%c%c%c_TAG %lu%s\n", (char)(chunk>>24),
+            (char)(chunk>>16), (char)(chunk>>8), (char)chunk,
+            (unsigned long)code, code == last ? " /* DUPLICATE */" : "");
+
+         if (code < last) /* still some to go */
+            print_chunks(chunks, nchunks, code+1, last, best_c, best_mask, lut);
+      }
+
+      else
+         print_chunks(chunks, nchunks, first, last, best_c, best_mask, lut);
+   }
+}
+
+static unsigned int primes[] =
+{
+   0, 1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67,
+   71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149,
+   151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229,
+   233, 239, 241, 251
+};
+
+#define NPRIMES ((sizeof primes)/(sizeof primes[0]))
+
+int
+main(void)
+{
+   /* Stdin should just contain chunk names, one per line */
+   png_uint_32 best_mask;
+   unsigned int best_c[4];
+   png_uint_32 chunks[CHUNK_COUNT_MAX];
+   png_byte known_chunk_count;
+
+   /* Not required; stop GCC whining: */
+   memset(best_c, 0xab, sizeof best_c);
+   best_mask = 0x12345678;
+
+   {
+      png_uint_32 this_chunk = 0;
+      png_byte n_chunks = 0;
+
+      for (;;)
+      {
+         int ch = getchar();
+
+         if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z'))
+         {
+            if (this_chunk > 0xffffffU)
+               error("chunk name too long");
+
+            this_chunk = (this_chunk << 8) + (unsigned)ch;
+         }
+
+         else
+         {
+            if (this_chunk > 0)
+            {
+               if (this_chunk <= 0xffffffU)
+                  error("chunk name too short");
+
+               if (n_chunks >= CHUNK_COUNT_MAX)
+                  error("too many chunks (check CHUNK_COUNT_MAX)");
+
+               chunks[n_chunks++] = this_chunk;
+               this_chunk = 0;
+            }
+         }
+
+         if (ch < 0)
+            break;
+      }
+
+      /* 22 is the number of chunks currently defined (excluding fRAc), at any
+       * time it should also be in PNG_KNOWN_CHUNK_COUNT, but this run of
+       * chunkhash may be trying to add a chunk so allow bigger numbers.
+       */
+#     ifdef PNG_KNOWN_CHUNK_COUNT
+#        define CHUNK_COUNT_MIN PNG_KNOWN_CHUNK_COUNT
+#     else
+#        define CHUNK_COUNT_MIN 26
+#     endif
+      if (n_chunks < CHUNK_COUNT_MIN)
+         error("too few chunks (expecting at least 26)");
+
+      known_chunk_count = n_chunks;
+   }
+
+   /* Exhaustive search of the hash parameters - in fact this isn't very slow at
+    * all.
+    */
+   {
+      unsigned int i1, c_zero = 0, c_one = 0;
+
+      for (i1=0; i1<NPRIMES; ++i1)
+      {
+         unsigned int i2;
+         unsigned int c[4];
+
+         fprintf(stderr, "TEST: %u\n", primes[i1]);
+         c[0] = primes[i1];
+
+         for (i2=0; i2<NPRIMES; ++i2)
+         {
+            unsigned int i3;
+
+            c[1] = primes[i2];
+
+            for (i3=0; i3<NPRIMES; ++i3)
+            {
+               unsigned int i4;
+
+               c[2] = primes[i3];
+
+               for (i4=0; i4<NPRIMES; ++i4)
+               {
+                  unsigned int i;
+                  png_uint_32 hash_mask = 0xffU;
+                  png_uint_32 hashes[CHUNK_COUNT_MAX];
+
+                  c[3] = primes[i4];
+
+                  while (hash_mask > 0xfU)
+                  {
+                     for (i=0; i<known_chunk_count; ++i)
+                     {
+                        unsigned int j;
+                        png_uint_32 hash = test_hash(chunks[i], c, hash_mask);
+
+                        for (j=0; j<i; ++j) if (hashes[j] == hash) goto next_i4;
+
+                        hashes[i] = hash;
+                     }
+
+                     hash_mask >>= 1;
+                  }
+
+               next_i4:
+                  if (hash_mask < 0xffU)
+                  {
+                     /* This worked */
+                     unsigned int best, c0 = 0, c1 = 0;
+
+                     hash_mask <<= 1;
+                     hash_mask += 1;
+
+                     for (i=0; i<4; ++i)
+                     {
+                        if (c[i] == 0)
+                           ++c0;
+
+                        else if (c[i] == 1)
+                           ++c1;
+                     }
+
+                     if (hash_mask == best_mask)
+                        best = (c0 > c_zero) || (c0 == c_zero && c1 > c_one);
+
+                     else
+                        best = (hash_mask < best_mask);
+
+                     if (best)
+                     {
+                        fprintf(stderr, "{%u,%u,%u,%u} & 0x%lx\n",
+                           c[0], c[1], c[2], c[3],
+                           (unsigned long)hash_mask);
+
+                        c_zero = c0;
+                        c_one = c1;
+                        best_mask = hash_mask;
+                        memcpy(best_c, c, sizeof best_c);
+                     }
+                  }
+               } /* i4 */
+            } /* i3 */
+         } /* i2 */
+      } /* i1 */
+   }
+
+   /* Calculate the LUT (png_chunk_hash) */
+   {
+      png_byte b;
+      png_byte lut[256];
+
+      /* A failure returns PNG_KNOWN_CHUNK_COUNT: */
+      memset(lut, known_chunk_count, sizeof lut);
+
+      for (b=0; b<known_chunk_count; ++b)
+         lut[test_hash(chunks[b], best_c, best_mask)] = b;
+
+      /* Validate the pngpriv.h hash function. */
+#     define png_chunk_hash lut
+         {
+            unsigned int i;
+
+            for (i=0; i<known_chunk_count; ++i)
+            {
+               png_uint_32 chunk = chunks[i];
+
+               if (PNG_CHUNK_HASH(chunk) != i)
+                  error("internal error: hash didn't work!");
+            }
+         }
+#     undef lut
+
+      /* Print all the results, first the stuff for pngpriv.h */
+      {
+         unsigned int i = 0;
+
+         while (strings[i] != 0)
+            puts(strings[i++]);
+
+         printf("#define PNG_CHUNK_HASH_MASK 0x%lxU\n",
+            (unsigned long)best_mask);
+         printf("#define PNG_CHUNK_HASH_C0 %u\n", best_c[0]);
+         printf("#define PNG_CHUNK_HASH_C1 %u\n", best_c[1]);
+         printf("#define PNG_CHUNK_HASH_C2 %u\n", best_c[2]);
+         printf("#define PNG_CHUNK_HASH_C3 %u\n", best_c[3]);
+
+         /* Print the hash codes of all the chunks */
+         putchar('\n');
+         print_chunks(chunks, known_chunk_count, 0, 0xffffffff, best_c,
+            best_mask, lut);
+         putchar('\n');
+         printf("#define PNG_KNOWN_CHUNK_COUNT %u\n", known_chunk_count);
+
+         while (strings[++i] != 0)
+            puts(strings[i]);
+
+         /* Now print the LUT */
+         fputs("   ", stdout);
+         {
+            unsigned int j;
+
+            for (j=0; j<=best_mask; ++j)
+            {
+               printf("%d", lut[j]);
+
+               if ((j % 16) == 15 && j < best_mask)
+                  printf(",\n   ");
+
+               else if (j < best_mask)
+                  printf(", ");
+
+               else
+                  printf("\n");
+            }
+         }
+
+         /* And the trailing text */
+         while (strings[++i] != 0)
+            puts(strings[i]);
+      }
+   }
+
+   exit(0);
+}

contrib/tools/chunkhash.h

@@ -0,0 +1,97 @@
+/* chunkhash.h -- a perfect hash code for the chunk names in png.h
+ *
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ *
+ * THIS IS A MACHINE GENERATED FILE.  See contrib/tools/chunkhash.c for
+ * copyright and other information.
+ *
+ * USAGE:  To include the PNG_CHUNK_HASH macro and associated definitions:
+ *
+ * #define PNG_CHUNKHASH_DEFS
+ * #include "contrib/tools/chunkhash.h"
+ *
+ * To define the png_chunk_hash array used by the macro:
+ *
+ * #define PNG_CHUNKHASH_CODE
+ * #include "contrib/tools/chunkhash.h"
+ *
+ * One or both of the defines must be given except when building chunkhash
+ * itself.
+ */
+#ifdef PNG_CHUNKHASH_DEFS
+#ifndef PNG_CHUNKHASH_H
+#define PNG_CHUNKHASH_H
+/* A perfect hash code - returns a value 0..(PNG_KNOWN_CHUNK_COUNT-1) and is
+ * generated by the ridiculously simple program in contrib/tools/chunkhash.c
+ *
+ * The hash code used here multiplies each byte by a different constant to
+ * return a single number:
+ *
+ *    b0 * c[0] + b1 * [c1] + b2 * c[2] + b3 * c[3]
+ *
+ * The values of the constants are found by search using the a table of
+ * primes, including 0, and may be (in fact are at present) 0 for some of the
+ * bytes, the compiler is expected to optimize multiply by zero, or one!
+ *
+ * The lookup table reduces the sparse result of the hash calculation to the
+ * correct index values.  The chunks are indexed in the string order of the
+ * png_uint_32 chunk names.
+ */
+#define PNG_CHUNK_HASH_MASK 0x3fU
+#define PNG_CHUNK_HASH_C0 103
+#define PNG_CHUNK_HASH_C1 1
+#define PNG_CHUNK_HASH_C2 0
+#define PNG_CHUNK_HASH_C3 1
+
+#define PNG_CHUNK_IDAT_TAG 0
+#define PNG_CHUNK_IEND_TAG 1
+#define PNG_CHUNK_IHDR_TAG 2
+#define PNG_CHUNK_PLTE_TAG 3
+#define PNG_CHUNK_bKGD_TAG 4
+#define PNG_CHUNK_cHRM_TAG 5
+#define PNG_CHUNK_fRAc_TAG 6
+#define PNG_CHUNK_gAMA_TAG 7
+#define PNG_CHUNK_gIFg_TAG 8
+#define PNG_CHUNK_gIFt_TAG 9
+#define PNG_CHUNK_gIFx_TAG 10
+#define PNG_CHUNK_hIST_TAG 11
+#define PNG_CHUNK_iCCP_TAG 12
+#define PNG_CHUNK_iTXt_TAG 13
+#define PNG_CHUNK_oFFs_TAG 14
+#define PNG_CHUNK_pCAL_TAG 15
+#define PNG_CHUNK_pHYs_TAG 16
+#define PNG_CHUNK_sBIT_TAG 17
+#define PNG_CHUNK_sCAL_TAG 18
+#define PNG_CHUNK_sPLT_TAG 19
+#define PNG_CHUNK_sRGB_TAG 20
+#define PNG_CHUNK_sTER_TAG 21
+#define PNG_CHUNK_tEXt_TAG 22
+#define PNG_CHUNK_tIME_TAG 23
+#define PNG_CHUNK_tRNS_TAG 24
+#define PNG_CHUNK_zTXt_TAG 25
+
+#define PNG_KNOWN_CHUNK_COUNT 26
+
+extern const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1];
+#endif /* !PNG_CHUNKHASH_H */
+#endif /* PNG_CHUNKHASH_DEFS */
+
+#ifndef PNG_CHUNK_HASH
+#define PNG_CHUNK_HASH(chunk) (png_chunk_hash[PNG_CHUNK_HASH_MASK & (\
+      ((chunk) >> 24) * PNG_CHUNK_HASH_C0 +\
+      ((chunk) >> 16) * PNG_CHUNK_HASH_C1 +\
+      ((chunk) >>  8) * PNG_CHUNK_HASH_C2 +\
+      ((chunk)      ) * PNG_CHUNK_HASH_C3)])
+#endif
+
+#ifdef PNG_CHUNKHASH_CODE
+#ifndef PNG_CHUNKHASH_C
+#define PNG_CHUNKHASH_C
+const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1] = {
+   26, 3, 26, 26, 26, 26, 26, 13, 26, 26, 26, 16, 26, 26, 26, 26,
+   26, 24, 12, 26, 18, 26, 26, 26, 26, 20, 26, 17, 26, 26, 25, 15,
+   26, 8, 14, 26, 26, 22, 26, 26, 1, 19, 5, 21, 26, 26, 9, 26,
+   26, 26, 10, 7, 26, 11, 26, 0, 26, 2, 23, 26, 26, 4, 26, 6
+};
+#endif /* !PNG_CHUNKHASH_C */
+#endif /* PNG_CHUNKHASH_CODE */

contrib/tools/png-fix-itxt.c

@@ -1,8 +1,8 @@
-#include <stdio.h>
 
-/* fixitxt version 1.0.0
+/* png-fix-itxt version 1.0.0
  *
  * Copyright 2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.3 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -10,7 +10,7 @@
  *
  * Usage:            
  *
- *     fixitxt.exe < bad.png > good.png
+ *     png-fix-itxt.exe < bad.png > good.png
  *
  * Fixes a PNG file written with libpng-1.6.0 or 1.6.1 that has one or more
  * uncompressed iTXt chunks.  Assumes that the actual length is greater
@@ -22,20 +22,28 @@
  *
  * Requires zlib (for crc32 and Z_NULL); build with
  *
- *     gcc -O -o fixitxt fixitxt.c -lz
+ *     gcc -O -o png-fix-itxt png-fix-itxt.c -lz
+ *
+ * If you need to handle iTXt chunks larger than 500000 kbytes you must
+ * rebuild png-fix-itxt with a larger values of MAX_LENGTH (or a smaller value
+ * if you know you will never encounter such huge iTXt chunks).
  */
 
+#include <stdio.h>
+#include <zlib.h>
+
 #define MAX_LENGTH 500000
 
-#define GETBREAK c=getchar(); if (c == EOF) break;
-#include <zlib.h>
+#define GETBREAK ((unsigned char)(inchar=getchar())); if (inchar == EOF) break
 
-main()
+int
+main(void)
 {
    unsigned int i;
    unsigned char buf[MAX_LENGTH];
    unsigned long crc;
-   unsigned int c;
+   unsigned char c;
+   int inchar;
 
 /* Skip 8-byte signature */
    for (i=8; i; i--)
@@ -44,17 +52,16 @@ main()
       putchar(c);
    }
 
-if (c != EOF)
+if (inchar != EOF)
 for (;;)
  {
    /* Read the length */
-   unsigned long length;
-   c=GETBREAK; buf[0] = c;
-   c=GETBREAK; buf[1] = c;
-   c=GETBREAK; buf[2] = c;
-   c=GETBREAK; buf[3] = c;
+   unsigned long length; /* must be 32 bits! */
+   c=GETBREAK; buf[0] = c; length  = c; length <<= 8;
+   c=GETBREAK; buf[1] = c; length += c; length <<= 8;
+   c=GETBREAK; buf[2] = c; length += c; length <<= 8;
+   c=GETBREAK; buf[3] = c; length += c;
 
-   length=((((unsigned long) buf[0]<<8 + buf[1]<<16) + buf[2] << 8) + buf[3]);
    /* Read the chunkname */
    c=GETBREAK; buf[4] = c;
    c=GETBREAK; buf[5] = c;
@@ -102,10 +109,10 @@ for (;;)
       }
 
       /* Update length bytes */
-        buf[0] = (length << 24) & 0xff;
-        buf[1] = (length << 16) & 0xff;
-        buf[2] = (length <<  8) & 0xff;
-        buf[3] = (length      ) & 0xff;
+      buf[0] = (unsigned char)((length << 24) & 0xff);
+      buf[1] = (unsigned char)((length << 16) & 0xff);
+      buf[2] = (unsigned char)((length <<  8) & 0xff);
+      buf[3] = (unsigned char)((length      ) & 0xff);
 
       /* Write the fixed iTXt chunk (length, name, data, crc) */
       for (i=0; i<length+12; i++)
@@ -125,7 +132,7 @@ for (;;)
          putchar(c);
       }
 
-      if (c == EOF)
+      if (inchar == EOF)
       {
          break;
       }
@@ -135,10 +142,12 @@ for (;;)
          break;
    }
 
-   if (c == EOF)
+   if (inchar == EOF)
       break;
 
    if (buf[4] == 73 && buf[5] == 69 && buf[6] == 78 && buf[7] == 68)
      break;
  }
+
+ return 0;
 }

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 1.6.0 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.3 [(PENDING RELEASE)]
  * Maintained 1998-2013 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
  * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -441,9 +441,9 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    /* If we don't have another value */
    else
    {
-      screen_gamma = 2.2;  /* A good guess for a PC monitor in a dimly
-                              lit room */
-      screen_gamma = 1.7 or 1.0;  /* A good guess for Mac systems */
+      screen_gamma = PNG_DEFAULT_sRGB;  /* A good guess for a PC monitor
+                                           in a dimly lit room */
+      screen_gamma = PNG_GAMMA_MAC_18 or 1.0; /* Good guesses for Mac systems */
    }
 
    /* Tell libpng to handle the gamma conversion for you.  The final call
@@ -455,7 +455,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    int intent;
 
    if (png_get_sRGB(png_ptr, info_ptr, &intent))
-      png_set_gamma(png_ptr, screen_gamma, 0.45455);
+      png_set_gamma(png_ptr, screen_gamma, PNG_DEFAULT_sRGB);
    else
    {
       double image_gamma;

libpng-manual.txt

@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.7.0beta09 - April 18, 2013
+ libpng version 1.7.0beta18 - September 16, 2013
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.7.0beta09 - April 18, 2013
+ libpng versions 0.97, January 1998, through 1.7.0beta18 - September 16, 2013
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
@@ -51,9 +51,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 I. Introduction
 
 This file describes how to use and modify the PNG reference library
-(known as libpng) for your own use.  There are five sections to this
-file: introduction, structures, reading, writing, and modification and
-configuration notes for various special platforms.  In addition to this
+(known as libpng) for your own use.  In addition to this
 file, example.c is a good starting point for using the library, as
 it is heavily commented and should include everything most people
 will need.  We assume that libpng is already installed; see the
@@ -741,7 +739,7 @@ situations:
                      encoding.
 
 You would use the linear (unencoded) value if you need to process the pixel
-values further because this avoids the need to decode and reencode each
+values further because this avoids the need to decode and re-encode each
 component value whenever arithmetic is performed.  A lot of graphics software
 uses linear values for this reason, often with higher precision component values
 to preserve overall accuracy.
@@ -2290,7 +2288,7 @@ For a more compact example of reading a PNG image, see the file example.c.
 
 Reading PNG files progressively
 
-The progressive reader is slightly different then the non-progressive
+The progressive reader is slightly different from the non-progressive
 reader.  Instead of calling png_read_info(), png_read_rows(), and
 png_read_end(), you make one call to png_process_data(), which calls
 callbacks when it has the info, a row, or the end of the image.  You
@@ -3092,13 +3090,34 @@ a writeable buffer of at least 29 bytes.
 
 Writing unknown chunks
 
-You can use the png_set_unknown_chunks function to queue up chunks
-for writing.  You give it a chunk name, raw data, and a size; that's
-all there is to it.  The chunks will be written by the next following
-png_write_info_before_PLTE, png_write_info, or png_write_end function.
-Any chunks previously read into the info structure's unknown-chunk
-list will also be written out in a sequence that satisfies the PNG
-specification's ordering rules.
+You can use the png_set_unknown_chunks function to queue up private chunks
+for writing.  You give it a chunk name, location, raw data, and a size.  You
+also must use png_set_keep_unknown_chunks() to ensure that libpng will
+handle them.  That's all there is to it.  The chunks will be written by the
+next following png_write_info_before_PLTE, png_write_info, or png_write_end
+function, depending upon the specified location.  Any chunks previously
+read into the info structure's unknown-chunk list will also be written out
+in a sequence that satisfies the PNG specification's ordering rules.
+
+Here is an example of writing two private chunks, prVt and miNE:
+
+    #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+    /* Set unknown chunk data */
+    png_unknown_chunk unk_chunk[2];
+    strcpy((char *) unk_chunk[0].name, "prVt";
+    unk_chunk[0].data = (unsigned char *) "PRIVATE DATA";
+    unk_chunk[0].size = strlen(unk_chunk[0].data)+1;
+    unk_chunk[0].location = PNG_HAVE_IHDR;
+    strcpy((char *) unk_chunk[1].name, "miNE";
+    unk_chunk[1].data = (unsigned char *) "MY CHUNK DATA";
+    unk_chunk[1].size = strlen(unk_chunk[0].data)+1;
+    unk_chunk[1].location = PNG_AFTER_IDAT;
+    png_set_unknown_chunks(write_ptr, write_info_ptr,
+        unk_chunk, 2);
+    /* Needed because miNE is not safe-to-copy */
+    png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS,
+       (png_bytep) "miNE", 1);
+    #endif
 
 The high-level write interface
 
@@ -3502,7 +3521,7 @@ The simplified API, which became available in libpng-1.6.0, hides the details
 of both libpng and the PNG file format itself.
 It allows PNG files to be read into a very limited number of
 in-memory bitmap formats or to be written from the same formats.  If these
-formats do not accomodate your needs then you can, and should, use the more
+formats do not accommodate your needs then you can, and should, use the more
 sophisticated APIs above - these support a wide variety of in-memory formats
 and a wide variety of sophisticated transformations to those formats as well
 as a wide variety of APIs to manipulate ancilliary information.
@@ -3993,9 +4012,12 @@ as warnings.
 
     png_set_benign_errors (png_ptr, int allowed);
 
-    allowed: 0: (default) treat png_benign_error() an error.
+    allowed: 0: treat png_benign_error() as an error.
              1: treat png_benign_error() as a warning.
 
+As of libpng-1.6.0, the default condition is to treat benign errors as
+warnings while reading and as errors while writing.
+
 Custom chunks
 
 If you need to read or write custom chunks, you may need to get deeper
@@ -4266,7 +4288,7 @@ the message, "message" is the formatted string to be printed,
 and p1 and p2 are parameters that are to be embedded in the string
 according to printf-style formatting directives.  For example,
 
-   png_debug1(2, "foo=%d\n", foo);
+   png_debug1(2, "foo=%d", foo);
 
 is expanded to
 
@@ -4573,7 +4595,7 @@ it has not been well tested and doesn't actually "dither".
 The code was not
 removed, however, and could be enabled by building libpng with
 PNG_READ_DITHER_SUPPORTED defined.  In libpng-1.4.2, this support
-was reenabled, but the function was renamed png_set_quantize() to
+was re-enabled, but the function was renamed png_set_quantize() to
 reflect more accurately what it actually does.  At the same time,
 the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to
 PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED
@@ -4717,7 +4739,7 @@ did not exist.)
 Applications can now choose whether to use these macros or to call the
 corresponding function by defining PNG_USE_READ_MACROS or
 PNG_NO_USE_READ_MACROS before including png.h.  Notice that this is
-only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0
+only supported from 1.5.0; defining PNG_NO_USE_READ_MACROS prior to 1.5.0
 will lead to a link failure.
 
 Prior to libpng-1.5.4, the zlib compressor used the same set of parameters
@@ -4753,6 +4775,9 @@ limits are now
    png_user_chunk_cache_max  0 (unlimited)   128
    png_user_chunk_malloc_max 0 (unlimited) 8,000,000
 
+The png_set_option() function (and the "options" member of the png struct) was
+added to libpng-1.5.15.
+
 B. Changes to the build and configuration of libpng
 
 Details of internal changes to the library code can be found in the CHANGES
@@ -4946,9 +4971,9 @@ symbols, using the PNG_PREFIX macro.
 
 We no longer include string.h in png.h.  The include statement has been moved
 to pngpriv.h, where it is not accessible by applications.  Applications that
-need access to information in string.h must add an '#include "string.h"'
+need access to information in string.h must add an '#include <string.h>'
 directive.  It does not matter whether this is placed prior to or after
-the '"#include png.h"' directive.
+the '#include "png.h"' directive.
 
 The following API are now DEPRECATED:
    png_info_init_3()
@@ -4983,9 +5008,16 @@ even if the image only contains gray pixels, only RGB profiles may appear
 in images with color type 2, 3, or 6, is now enforced.  The sRGB chunk
 is allowed to appear in images with any color type.
 
+Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
+an empty language field or an empty translated keyword.  Both of these
+are allowed by the PNG specification, so these warnings are no longer issued.
+
 The library now issues an error if the application attempts to set a
 transform after it calls png_read_update_info().
 
+The default condition for benign_errors is now to treat benign errors as
+warnings while reading and as errors while writing.
+
 The library now issues a warning if both background processing and RGB to
 gray are used when gamma correction happens. As with previous versions of
 the library the results are numerically very incorrect in this case.
@@ -5002,6 +5034,25 @@ The machine-generated configure files are no longer included in branches
 libpng16 and later of the GIT repository.  They continue to be included
 in the tarball releases, however.
 
+Libpng-1.6.0 and later use the CMF bytes at the beginning of the IDAT stream
+to set the size of the sliding window for reading instead of using the default
+32-kbyte sliding window size.  It was discovered that there are hundreds of PNG
+files in the wild that have incorrect CMF bytes that cause libpng to now issue
+a "too far back" error and reject the file.  Libpng-1.6.3 provides a way to
+revert to the libpng-1.5.x behavior (ignoring the CMF bytes and using a
+32-kbyte sliding window), by using
+
+    png_set_option(png_ptr, PNG_MAXIMUM_INFLATE_WINDOW,
+        PNG_OPTION_ON);
+
+and provides a tool (contrib/tools/pngfix) for optimizing the CMF bytes
+correctly.
+
+Libpng-1.6.0 and libpng-1.6.1 wrote uncompressed iTXt chunks with the wrong
+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.
+
 XIII.  Changes to Libpng from version 1.6.x to 1.7.x
 
 Some functions that were deprecated in libpng-1.6.0 were removed:
@@ -5196,13 +5247,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 XVII. Y2K Compliance in libpng
 
-April 18, 2013
+September 16, 2013
 
 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 1.7.0beta09 are Y2K compliant.  It is my belief that earlier
+upward through 1.7.0beta18 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

libpng.3

@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "April 18, 2013"
+.TH LIBPNG 3 "September 16, 2013"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta09
+libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta18
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -494,7 +494,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.7.0beta09 - April 18, 2013
+ libpng version 1.7.0beta18 - September 16, 2013
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -505,7 +505,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.7.0beta09 - April 18, 2013
+ libpng versions 0.97, January 1998, through 1.7.0beta18 - September 16, 2013
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
@@ -545,9 +545,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 .SH I. Introduction
 
 This file describes how to use and modify the PNG reference library
-(known as libpng) for your own use.  There are five sections to this
-file: introduction, structures, reading, writing, and modification and
-configuration notes for various special platforms.  In addition to this
+(known as libpng) for your own use.  In addition to this
 file, example.c is a good starting point for using the library, as
 it is heavily commented and should include everything most people
 will need.  We assume that libpng is already installed; see the
@@ -665,7 +663,7 @@ All APIs that take (double) arguments also have a matching API that
 takes the corresponding fixed point integer arguments.  The fixed point
 API has the same name as the floating point one with "_fixed" appended.
 The actual range of values permitted in the APIs is frequently less than
-the full range of (png_fixed_point) (-21474 to +21474).  When APIs require
+the full range of (png_fixed_point) (\-21474 to +21474).  When APIs require
 a non-negative argument the type is recorded as png_uint_32 above.  Consult
 the header file and the text below for more information.
 
@@ -706,7 +704,7 @@ The easiest way to make minor changes to the libpng configuration when
 auto-configuration is supported is to add definitions to the command line
 using (typically) CPPFLAGS.  For example:
 
-CPPFLAGS=-DPNG_NO_FLOATING_ARITHMETIC
+CPPFLAGS=\-DPNG_NO_FLOATING_ARITHMETIC
 
 will change the internal libpng math implementation for gamma correction and
 other arithmetic calculations to fixed point, avoiding the need for fast
@@ -714,7 +712,7 @@ floating point support.  The result can be seen in the generated pnglibconf.h -
 make sure it contains the changed feature macro setting.
 
 If you need to make more extensive configuration changes - more than one or two
-feature macro settings - you can either add -DPNG_USER_CONFIG to the build
+feature macro settings - you can either add \-DPNG_USER_CONFIG to the build
 command line and put a list of feature macro settings in pngusr.h or you can set
 DFA_XTRA (a makefile variable) to a file containing the same information in the
 form of 'option' settings.
@@ -773,7 +771,7 @@ pngusr.dfa in these directories.
 
 C. Configuration using PNG_USR_CONFIG
 
-If -DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file
+If \-DPNG_USR_CONFIG is added to the CFLAGS when pnglibconf.h is built the file
 pngusr.h will automatically be included before the options in
 scripts/pnglibconf.dfa are processed.  Your pngusr.h file should contain only
 macro definitions turning features on or off or setting settings.
@@ -1003,7 +1001,7 @@ input stream. You must supply the function
           unknown chunk structure, process it, and return one
           of the following: */
 
-       return (-n); /* chunk had an error */
+       return (\-n); /* chunk had an error */
        return (0); /* did not recognize */
        return (n); /* success */
     }
@@ -1054,7 +1052,7 @@ non-interlaced case the row that was just handled is simply one less than the
 passed in row number, and pass will always be 0.  For the interlaced case the
 same applies unless the row value is 0, in which case the row just handled was
 the last one from one of the preceding passes.  Because interlacing may skip a
-pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+pass you cannot be sure that the preceding pass is just 'pass\-1', if you really
 need to know what the last pass is record (row,pass) from the callback and use
 the last recorded value each time.
 
@@ -1142,7 +1140,7 @@ callback function:
 .SS 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.
+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
@@ -1235,7 +1233,7 @@ situations:
                      encoding.
 
 You would use the linear (unencoded) value if you need to process the pixel
-values further because this avoids the need to decode and reencode each
+values further because this avoids the need to decode and re-encode each
 component value whenever arithmetic is performed.  A lot of graphics software
 uses linear values for this reason, often with higher precision component values
 to preserve overall accuracy.
@@ -2714,13 +2712,13 @@ point to libpng-allocated storage with the following function:
            or simply PNG_FREE_ALL
 
     seq  - sequence number of item to be freed
-           (-1 for all items)
+           (\-1 for all items)
 
 This function may be safely called when the relevant storage has
 already been freed, or has not yet been allocated, or was allocated
 by the user and not by libpng,  and will in those cases do nothing.
 The "seq" parameter is ignored if only one item of the selected data
-type, such as PLTE, is allowed.  If "seq" is not -1, and multiple items
+type, such as PLTE, is allowed.  If "seq" is not \-1, and multiple items
 are allowed for the data type identified in the mask, such as text or
 sPLT, only the n'th item in the structure is freed, where n is "seq".
 
@@ -2784,7 +2782,7 @@ For a more compact example of reading a PNG image, see the file example.c.
 
 .SS Reading PNG files progressively
 
-The progressive reader is slightly different then the non-progressive
+The progressive reader is slightly different from the non-progressive
 reader.  Instead of calling png_read_info(), png_read_rows(), and
 png_read_end(), you make one call to png_process_data(), which calls
 callbacks when it has the info, a row, or the end of the image.  You
@@ -3121,7 +3119,7 @@ non-interlaced case the row that was just handled is simply one less than the
 passed in row number, and pass will always be 0.  For the interlaced case the
 same applies unless the row value is 0, in which case the row just handled was
 the last one from one of the preceding passes.  Because interlacing may skip a
-pass you cannot be sure that the preceding pass is just 'pass-1', if you really
+pass you cannot be sure that the preceding pass is just 'pass\-1', if you really
 need to know what the last pass is record (row,pass) from the callback and use
 the last recorded value each time.
 
@@ -3586,13 +3584,34 @@ a writeable buffer of at least 29 bytes.
 
 .SS Writing unknown chunks
 
-You can use the png_set_unknown_chunks function to queue up chunks
-for writing.  You give it a chunk name, raw data, and a size; that's
-all there is to it.  The chunks will be written by the next following
-png_write_info_before_PLTE, png_write_info, or png_write_end function.
-Any chunks previously read into the info structure's unknown-chunk
-list will also be written out in a sequence that satisfies the PNG
-specification's ordering rules.
+You can use the png_set_unknown_chunks function to queue up private chunks
+for writing.  You give it a chunk name, location, raw data, and a size.  You
+also must use png_set_keep_unknown_chunks() to ensure that libpng will
+handle them.  That's all there is to it.  The chunks will be written by the
+next following png_write_info_before_PLTE, png_write_info, or png_write_end
+function, depending upon the specified location.  Any chunks previously
+read into the info structure's unknown-chunk list will also be written out
+in a sequence that satisfies the PNG specification's ordering rules.
+
+Here is an example of writing two private chunks, prVt and miNE:
+
+    #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+    /* Set unknown chunk data */
+    png_unknown_chunk unk_chunk[2];
+    strcpy((char *) unk_chunk[0].name, "prVt";
+    unk_chunk[0].data = (unsigned char *) "PRIVATE DATA";
+    unk_chunk[0].size = strlen(unk_chunk[0].data)+1;
+    unk_chunk[0].location = PNG_HAVE_IHDR;
+    strcpy((char *) unk_chunk[1].name, "miNE";
+    unk_chunk[1].data = (unsigned char *) "MY CHUNK DATA";
+    unk_chunk[1].size = strlen(unk_chunk[0].data)+1;
+    unk_chunk[1].location = PNG_AFTER_IDAT;
+    png_set_unknown_chunks(write_ptr, write_info_ptr,
+        unk_chunk, 2);
+    /* Needed because miNE is not safe-to-copy */
+    png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS,
+       (png_bytep) "miNE", 1);
+    #endif
 
 .SS The high-level write interface
 
@@ -3927,13 +3946,13 @@ point to libpng-allocated storage with the following function:
             or simply PNG_FREE_ALL
 
     seq   - sequence number of item to be freed
-            (-1 for all items)
+            (\-1 for all items)
 
 This function may be safely called when the relevant storage has
 already been freed, or has not yet been allocated, or was allocated
 by the user  and not by libpng,  and will in those cases do nothing.
 The "seq" parameter is ignored if only one item of the selected data
-type, such as PLTE, is allowed.  If "seq" is not -1, and multiple items
+type, such as PLTE, is allowed.  If "seq" is not \-1, and multiple items
 are allowed for the data type identified in the mask, such as text or
 sPLT, only the n'th item in the structure is freed, where n is "seq".
 
@@ -3996,7 +4015,7 @@ The simplified API, which became available in libpng-1.6.0, hides the details
 of both libpng and the PNG file format itself.
 It allows PNG files to be read into a very limited number of
 in-memory bitmap formats or to be written from the same formats.  If these
-formats do not accomodate your needs then you can, and should, use the more
+formats do not accommodate your needs then you can, and should, use the more
 sophisticated APIs above - these support a wide variety of in-memory formats
 and a wide variety of sophisticated transformations to those formats as well
 as a wide variety of APIs to manipulate ancilliary information.
@@ -4487,9 +4506,12 @@ as warnings.
 
     png_set_benign_errors (png_ptr, int allowed);
 
-    allowed: 0: (default) treat png_benign_error() an error.
+    allowed: 0: treat png_benign_error() as an error.
              1: treat png_benign_error() as a warning.
 
+As of libpng-1.6.0, the default condition is to treat benign errors as
+warnings while reading and as errors while writing.
+
 .SS Custom chunks
 
 If you need to read or write custom chunks, you may need to get deeper
@@ -4761,12 +4783,12 @@ the message, "message" is the formatted string to be printed,
 and p1 and p2 are parameters that are to be embedded in the string
 according to printf-style formatting directives.  For example,
 
-   png_debug1(2, "foo=%d\n", foo);
+   png_debug1(2, "foo=%d", foo);
 
 is expanded to
 
    if (PNG_DEBUG > 2)
-      fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+      fprintf(PNG_DEBUG_FILE, "foo=%d\en", foo);
 
 When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
 can still use PNG_DEBUG to control your own debugging:
@@ -4783,7 +4805,7 @@ this version of libpng, but if you insert some they will be printed.
 
 Starting with libpng-1.6.0, you can configure libpng (when using the
 "configure" script) to prefix all exported symbols by means of the
-configuration option "--with-libpng-prefix=FOO_", where FOO_ can be any
+configuration option "\-\-with\-libpng\-prefix=FOO_", where FOO_ can be any
 string beginning with a letter and containing only uppercase
 and lowercase letters, digits, and the underscore (i.e., a C language
 identifier).  This creates a set of macros in pnglibconf.h, so this is
@@ -5068,7 +5090,7 @@ it has not been well tested and doesn't actually "dither".
 The code was not
 removed, however, and could be enabled by building libpng with
 PNG_READ_DITHER_SUPPORTED defined.  In libpng-1.4.2, this support
-was reenabled, but the function was renamed png_set_quantize() to
+was re-enabled, but the function was renamed png_set_quantize() to
 reflect more accurately what it actually does.  At the same time,
 the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to
 PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED
@@ -5106,7 +5128,7 @@ reading, and after png_write_png() or png_write_image() while writing.
 
    int max_palette = png_get_palette_max(png_ptr, info_ptr);
 
-This will return the maximum palette index found in the image, or "-1" if
+This will return the maximum palette index found in the image, or "\-1" if
 the palette was not checked, or "0" if no palette was found.  Note that this
 does not account for any palette index used by ancillary chunks such as the
 bKGD chunk; you must check those separately to determine the maximum
@@ -5212,7 +5234,7 @@ did not exist.)
 Applications can now choose whether to use these macros or to call the
 corresponding function by defining PNG_USE_READ_MACROS or
 PNG_NO_USE_READ_MACROS before including png.h.  Notice that this is
-only supported from 1.5.0 -defining PNG_NO_USE_READ_MACROS prior to 1.5.0
+only supported from 1.5.0; defining PNG_NO_USE_READ_MACROS prior to 1.5.0
 will lead to a link failure.
 
 Prior to libpng-1.5.4, the zlib compressor used the same set of parameters
@@ -5248,6 +5270,9 @@ limits are now
    png_user_chunk_cache_max  0 (unlimited)   128
    png_user_chunk_malloc_max 0 (unlimited) 8,000,000
 
+The png_set_option() function (and the "options" member of the png struct) was
+added to libpng-1.5.15.
+
 B. Changes to the build and configuration of libpng
 
 Details of internal changes to the library code can be found in the CHANGES
@@ -5441,9 +5466,9 @@ symbols, using the PNG_PREFIX macro.
 
 We no longer include string.h in png.h.  The include statement has been moved
 to pngpriv.h, where it is not accessible by applications.  Applications that
-need access to information in string.h must add an '#include "string.h"'
+need access to information in string.h must add an '#include <string.h>'
 directive.  It does not matter whether this is placed prior to or after
-the '"#include png.h"' directive.
+the '#include "png.h"' directive.
 
 The following API are now DEPRECATED:
    png_info_init_3()
@@ -5478,9 +5503,16 @@ even if the image only contains gray pixels, only RGB profiles may appear
 in images with color type 2, 3, or 6, is now enforced.  The sRGB chunk
 is allowed to appear in images with any color type.
 
+Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
+an empty language field or an empty translated keyword.  Both of these
+are allowed by the PNG specification, so these warnings are no longer issued.
+
 The library now issues an error if the application attempts to set a
 transform after it calls png_read_update_info().
 
+The default condition for benign_errors is now to treat benign errors as
+warnings while reading and as errors while writing.
+
 The library now issues a warning if both background processing and RGB to
 gray are used when gamma correction happens. As with previous versions of
 the library the results are numerically very incorrect in this case.
@@ -5497,6 +5529,25 @@ The machine-generated configure files are no longer included in branches
 libpng16 and later of the GIT repository.  They continue to be included
 in the tarball releases, however.
 
+Libpng-1.6.0 and later use the CMF bytes at the beginning of the IDAT stream
+to set the size of the sliding window for reading instead of using the default
+32-kbyte sliding window size.  It was discovered that there are hundreds of PNG
+files in the wild that have incorrect CMF bytes that cause libpng to now issue
+a "too far back" error and reject the file.  Libpng-1.6.3 provides a way to
+revert to the libpng-1.5.x behavior (ignoring the CMF bytes and using a
+32-kbyte sliding window), by using
+
+    png_set_option(png_ptr, PNG_MAXIMUM_INFLATE_WINDOW,
+        PNG_OPTION_ON);
+
+and provides a tool (contrib/tools/pngfix) for optimizing the CMF bytes
+correctly.
+
+Libpng-1.6.0 and libpng-1.6.1 wrote uncompressed iTXt chunks with the wrong
+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.
+
 .SH XIII.  Changes to Libpng from version 1.6.x to 1.7.x
 
 Some functions that were deprecated in libpng-1.6.0 were removed:
@@ -5671,7 +5722,7 @@ C binary operator and after "for" or "while", and before
 being cast, nor do we put one between a function name and the
 left parenthesis that follows it:
 
-    for (i = 2; i > 0; --i)
+    for (i = 2; i > 0; \-\-i)
        y[i] = a(x) + (int)b;
 
 We prefer #ifdef and #ifndef to #if defined() and #if !defined()
@@ -5691,13 +5742,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 .SH XVII. Y2K Compliance in libpng
 
-April 18, 2013
+September 16, 2013
 
 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 1.7.0beta09 are Y2K compliant.  It is my belief that earlier
+upward through 1.7.0beta18 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
@@ -5904,7 +5955,7 @@ the first widely used release:
  1.5.7               15    10507  15.so.15.7[.0]
  1.6.0beta01-37      16    10600  16.so.16.0[.0]
  1.7.0alpha01-10     17    10700  17.so.17.0[.0]
- 1.7.0beta01-09      17    10700  17.so.17.0[.0]
+ 1.7.0beta01-18      17    10700  17.so.17.0[.0]
 
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -5961,7 +6012,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.7.0beta09 - April 18, 2013:
+Libpng version 1.7.0beta18 - September 16, 2013:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -5984,7 +6035,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.7.0beta09, April 18, 2013, are
+libpng versions 1.2.6, August 15, 2004, through 1.7.0beta18, September 16, 2013, are
 Copyright (c) 2004,2006-2007 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
@@ -6083,7 +6134,7 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-April 18, 2013
+September 16, 2013
 
 .\" end of man page
 

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "April 18, 2013"
+.TH LIBPNGPF 3 "September 16, 2013"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta09
+libpng \- Portable Network Graphics (PNG) Reference Library 1.7.0beta18
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "April 18, 2013"
+.TH PNG 5 "September 16, 2013"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION

png.c

@@ -14,7 +14,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_7_0beta09 Your_png_h_is_not_version_1_7_0beta09;
+typedef png_libpng_version_1_7_0beta18 Your_png_h_is_not_version_1_7_0beta18;
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
@@ -691,13 +691,13 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.7.0beta09 - April 24, 2013" PNG_STRING_NEWLINE \
+     "libpng version 1.7.0beta18 - September 16, 2013" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2013 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE;
 #  else
-      return "libpng version 1.7.0beta09 - April 24, 2013\
+      return "libpng version 1.7.0beta18 - September 16, 2013\
       Copyright (c) 1998-2013 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -778,7 +778,7 @@ png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name)
    return PNG_HANDLE_CHUNK_AS_DEFAULT;
 }
 
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 int /* PRIVATE */
 png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name)
 {
@@ -787,7 +787,7 @@ png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name)
    PNG_CSTRING_FROM_CHUNK(chunk_string, chunk_name);
    return png_handle_as_unknown(png_ptr, chunk_string);
 }
-#endif /* READ_UNKNOWN_CHUNKS */
+#endif /* HANDLE_AS_UNKNOWN */
 #endif /* SET_UNKNOWN_CHUNKS */
 
 /* This function was added to libpng-1.0.7 */

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.7.0beta09 - April 24, 2013
+ * libpng version 1.7.0beta18 - September 16, 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.)
@@ -11,7 +11,7 @@
  * 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 1.7.0beta09 - April 24, 2013: Glenn
+ *   libpng versions 0.97, January 1998, through 1.7.0beta18 - September 16, 2013: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -168,7 +168,7 @@
  *    1.5.7                   15    10507  15.so.15.7[.0]
  *    1.6.0beta01-37          16    10600  16.so.16.0[.0]
  *    1.7.0alpha01-10         17    10700  17.so.17.0[.0]
- *    1.7.0beta01-09          17    10700  17.so.17.0[.0]
+ *    1.7.0beta01-18          17    10700  17.so.17.0[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -200,7 +200,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.7.0beta09, April 24, 2013, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.7.0beta18, September 16, 2013, are
  * Copyright (c) 2004, 2006-2013 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:
@@ -312,13 +312,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    April 24, 2013
+ *    September 16, 2013
  *
  *    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 1.7.0beta09 are Y2K compliant.  It is my belief that
+ *    upward through 1.7.0beta18 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
@@ -378,9 +378,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.7.0beta09"
+#define PNG_LIBPNG_VER_STRING "1.7.0beta18"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.7.0beta09 - April 24, 2013\n"
+     " libpng version 1.7.0beta18 - September 16, 2013\n"
 
 #define PNG_LIBPNG_VER_SONUM   17
 #define PNG_LIBPNG_VER_DLLNUM  17
@@ -394,7 +394,7 @@
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
-#define PNG_LIBPNG_VER_BUILD  09
+#define PNG_LIBPNG_VER_BUILD  18
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -527,7 +527,7 @@
  * For historical reasons these constants have the form png_<name>; i.e.
  * the prefix is lower case.  Please use decimal values as the parameters to
  * match the ISO PNG specification and to avoid relying on the C locale
- * interpretation of character values.
+ * interpretation of character values.  Please keep the list sorted.
  *
  * Notice that PNG_U32 is used to define a 32-bit value for the 4 byte chunk
  * type.  In fact the specification does not express chunk types this way,
@@ -544,21 +544,25 @@
  * In 1.7.0 the definitions were made public in png.h to avoid having to
  * duplicate the same definitions in application code.
  */
-#define png_IHDR PNG_U32( 73,  72,  68,  82)
 #define png_IDAT PNG_U32( 73,  68,  65,  84)
 #define png_IEND PNG_U32( 73,  69,  78,  68)
+#define png_IHDR PNG_U32( 73,  72,  68,  82)
 #define png_PLTE PNG_U32( 80,  76,  84,  69)
 #define png_bKGD PNG_U32( 98,  75,  71,  68)
 #define png_cHRM PNG_U32( 99,  72,  82,  77)
+#define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
 #define png_gAMA PNG_U32(103,  65,  77,  65)
+#define png_gIFg PNG_U32(103,  73,  70, 103)
+#define png_gIFt PNG_U32(103,  73,  70, 116) /* deprecated */
+#define png_gIFx PNG_U32(103,  73,  70, 120)
 #define png_hIST PNG_U32(104,  73,  83,  84)
 #define png_iCCP PNG_U32(105,  67,  67,  80)
 #define png_iTXt PNG_U32(105,  84,  88, 116)
 #define png_oFFs PNG_U32(111,  70,  70, 115)
 #define png_pCAL PNG_U32(112,  67,  65,  76)
-#define png_sCAL PNG_U32(115,  67,  65,  76)
 #define png_pHYs PNG_U32(112,  72,  89, 115)
 #define png_sBIT PNG_U32(115,  66,  73,  84)
+#define png_sCAL PNG_U32(115,  67,  65,  76)
 #define png_sPLT PNG_U32(115,  80,  76,  84)
 #define png_sRGB PNG_U32(115,  82,  71,  66)
 #define png_sTER PNG_U32(115,  84,  69,  82)
@@ -636,7 +640,7 @@ 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_7_0beta09;
+typedef char* png_libpng_version_1_7_0beta18;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -2916,7 +2920,8 @@ PNG_EXPORT(243, int, png_get_palette_max, (png_const_structrp png_ptr,
 #ifdef PNG_ARM_NEON_API_SUPPORTED
 #  define PNG_ARM_NEON   0 /* HARDWARE: ARM Neon SIMD instructions supported */
 #endif
-#define PNG_OPTION_NEXT  2 /* Next option - numbers must be even */
+#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
+#define PNG_OPTION_NEXT  4 /* Next option - numbers must be even */
 
 /* Return values: NOTE: there are four values and 'off' is *not* zero */
 #define PNG_OPTION_UNSET   0 /* Unset - defaults to off */
@@ -3340,6 +3345,7 @@ PNG_EXPORT(238, void, png_image_free, (png_imagep image));
 #endif /* PNG_SIMPLIFIED_READ_SUPPORTED */
 
 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
+#ifdef PNG_STDIO_SUPPORTED
 /* WRITE APIS
  * ----------
  * For write you must initialize a png_image structure to describe the image to
@@ -3382,6 +3388,7 @@ PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
  *
  * Note that the write API does not support interlacing or sub-8-bit pixels.
  */
+#endif /* PNG_STDIO_SUPPORTED */
 #endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */
 /*******************************************************************************
  *  END OF SIMPLIFIED API

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.7.0beta09 - April 18, 2013
+ * libpng version 1.7.0beta18 - September 16, 2013
  *
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)

pngget.c

@@ -1,7 +1,7 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+ * 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.)

pngmem.c

@@ -155,10 +155,12 @@ png_realloc_array,(png_structrp png_ptr, png_const_voidp old_array,
    }
 
 #ifdef PNG_READ_SUPPORTED
+# ifdef PNG_USER_LIMITS_SUPPORTED
    /* The potential overflow case.  Set the cache counter so libpng will
     * not make any more attempts
     */
    png_ptr->user_chunk_cache_max = 2;
+# endif
 #endif
 
    return NULL; /* error */

pngpread.c

@@ -151,7 +151,7 @@ png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
 void /* PRIVATE */
 png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
 {
-   png_size_t num_checked = png_ptr->sig_bytes,
+   png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */ 
              num_to_check = 8 - num_checked;
 
    if (png_ptr->buffer_size < num_to_check)

pngpriv.h

@@ -125,6 +125,46 @@
 
 #endif /* VERSION_INFO_ONLY */
 
+/* Compile time options.
+ * =====================
+ * In a multi-arch build the compiler may compile the code several times for the
+ * same object module, producing different binaries for different architectures.
+ * When this happens configure-time setting of the target host options cannot be
+ * done and this interferes with the handling of the ARM NEON optimizations, and
+ * possibly other similar optimizations.  Put additional tests here; in general
+ * this is needed when the same option can be changed at both compile time and
+ * run time depending on the target OS (i.e. iOS vs Android.)
+ *
+ * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
+ * this is not possible with certain compilers (Oracle SUN OS CC), as a result
+ * it is necessary to ensure that all extern functions that *might* be used
+ * regardless of $(CFLAGS) get declared in this file.  The test on __ARM_NEON__
+ * below is one example of this behavior because it is controlled by the
+ * presence or not of -mfpu=neon on the GCC command line, it is possible to do
+ * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
+ * do this.
+ */
+#ifndef PNG_ARM_NEON_OPT
+   /* ARM NEON optimizations are being controlled by the compiler settings,
+    * typically the target FPU.  If the FPU has been set to NEON (-mfpu=neon
+    * with GCC) then the compiler will define __ARM_NEON__ and we can rely
+    * unconditionally on NEON instructions not crashing, otherwise we must
+    * disable use of NEON instructions:
+    */
+#  ifdef __ARM_NEON__
+#     define PNG_ARM_NEON_OPT 2
+#  else
+#     define PNG_ARM_NEON_OPT 0
+#  endif
+#endif
+
+#if PNG_ARM_NEON_OPT > 0
+   /* NEON optimizations are to be at least considered by libpng, so enable the
+    * callbacks to do this.
+    */
+#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
+#endif
+
 /* Is this a build of a DLL where compilation of the object modules requires
  * different preprocessor settings to those required for a simple library?  If
  * so PNG_BUILD_DLL must be set.
@@ -629,6 +669,24 @@
 #include "pngstruct.h"
 #include "pnginfo.h"
 
+/* Validate the include paths - the include path used to generate pnglibconf.h
+ * must match that used in the build, or we must be using pnglibconf.h.prebuilt:
+ */
+#if PNG_ZLIB_VERNUM != 0 && PNG_ZLIB_VERNUM != ZLIB_VERNUM
+#  error ZLIB_VERNUM != PNG_ZLIB_VERNUM \
+      "-I (include path) error: see the notes in pngpriv.h"
+   /* This means that when pnglibconf.h was built the copy of zlib.h that it
+    * used is not the same as the one being used here.  Because the build of
+    * libpng makes decisions to use inflateInit2 and inflateReset2 based on the
+    * zlib version number and because this affects handling of certain broken
+    * PNG files the -I directives must match.
+    *
+    * The most likely explanation is that you passed a -I in CFLAGS, this will
+    * not work; all the preprocessor directories and in particular all the -I
+    * directives must be in CPPFLAGS.
+    */
+#endif
+
 /* This is used for 16 bit gamma tables -- only the top level pointers are
  * const; this could be changed:
  */
@@ -1285,15 +1343,13 @@ PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
     * just skips the chunk or errors out if it is critical.
     */
 
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 PNG_INTERNAL_FUNCTION(int,png_chunk_unknown_handling,
     (png_const_structrp png_ptr, png_uint_32 chunk_name),PNG_EMPTY);
    /* Exactly as the API png_handle_as_unknown() except that the argument is a
     * 32-bit chunk name, not a string.
     */
-#endif
-#endif /* PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
+#endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
 #endif /* PNG_READ_SUPPORTED */
 
 /* Handle the transformations for reading and writing */
@@ -1830,14 +1886,22 @@ PNG_INTERNAL_FUNCTION(void, png_image_free, (png_imagep image), PNG_EMPTY);
 
 #endif /* SIMPLIFIED READ/WRITE */
 
+/* These are initialization functions for hardware specific PNG filter
+ * optimizations; list these here then select the appropriate one at compile
+ * time using the macro PNG_FILTER_OPTIMIZATIONS.  If the macro is not defined
+ * the generic code is used.
+ */
 #ifdef PNG_FILTER_OPTIMIZATIONS
 PNG_INTERNAL_FUNCTION(void, PNG_FILTER_OPTIMIZATIONS, (png_structrp png_ptr,
-    unsigned int bpp), PNG_EMPTY);
-   /* This is the initialization function for hardware specific optimizations,
-    * one implementation (for ARM NEON machines) is contained in
-    * arm/filter_neon.c.  It need not be defined - the generic code will be used
-    * if not.
+   unsigned int bpp), PNG_EMPTY);
+   /* Just declare the optimization that will be used */
+#else
+   /* List *all* the possible optimizations here - this branch is required if
+    * the builder of libpng passes the definition of PNG_FILTER_OPTIMIZATIONS in
+    * CFLAGS in place of CPPFLAGS *and* uses symbol prefixing.
     */
+PNG_INTERNAL_FUNCTION(void, png_init_filter_functions_neon,
+   (png_structp png_ptr, unsigned int bpp), PNG_EMPTY);
 #endif
 
 /* Maintainer: Put new private prototypes here ^ */

pngread.c

@@ -3285,7 +3285,7 @@ png_image_read_background(png_voidp argument)
 
       case 8:
          /* 8-bit sRGB gray values with an alpha channel; the alpha channel is
-          * to be removed by composing on a backgroundi: either the row if
+          * to be removed by composing on a background: either the row if
           * display->background is NULL or display->background->green if not.
           * Unlike the code above ALPHA_OPTIMIZED has *not* been done.
           */

pngrtran.c

@@ -1357,12 +1357,18 @@ png_init_palette_transformations(png_structrp png_ptr)
 
       /* Ignore if all the entries are opaque (unlikely!) */
       for (i=0; i<png_ptr->num_trans; ++i)
+      {
          if (png_ptr->trans_alpha[i] == 255)
             continue;
          else if (png_ptr->trans_alpha[i] == 0)
             input_has_transparency = 1;
          else
+         {
+            input_has_transparency = 1;
             input_has_alpha = 1;
+            break;
+         }
+      }
    }
 
    /* If no alpha we can optimize. */
@@ -1775,31 +1781,34 @@ png_init_read_transformations(png_structrp png_ptr)
        * the number of significant bits is 0 then no shift is done (this is an
        * error condition which is silently ignored.)
        */
-      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
-      {
-         int component = png_ptr->palette[i].red;
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].red;
 
-         component >>= shift;
-         png_ptr->palette[i].red = (png_byte)component;
-      }
+            component >>= shift;
+            png_ptr->palette[i].red = (png_byte)component;
+         }
 
       shift = 8 - png_ptr->sig_bit.green;
-      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
-      {
-         int component = png_ptr->palette[i].green;
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].green;
 
-         component >>= shift;
-         png_ptr->palette[i].green = (png_byte)component;
-      }
+            component >>= shift;
+            png_ptr->palette[i].green = (png_byte)component;
+         }
 
       shift = 8 - png_ptr->sig_bit.blue;
-      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
-      {
-         int component = png_ptr->palette[i].blue;
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].blue;
 
-         component >>= shift;
-         png_ptr->palette[i].blue = (png_byte)component;
-      }
+            component >>= shift;
+            png_ptr->palette[i].blue = (png_byte)component;
+         }
    }
 #endif  /* PNG_READ_SHIFT_SUPPORTED */
 }

pngrutil.c

@@ -311,7 +311,7 @@ png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
  * chunk apparently owns the stream.  Prior to release it does a png_error.
  */
 static int
-png_inflate_claim(png_structrp png_ptr, png_uint_32 owner, int window_bits)
+png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
 {
    if (png_ptr->zowner != 0)
    {
@@ -346,6 +346,22 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner, int window_bits)
     */
    {
       int ret; /* zlib return code */
+#     if PNG_ZLIB_VERNUM >= 0x1240
+
+#        if defined(PNG_SET_OPTION_SUPPORTED) && \
+            defined(PNG_MAXIMUM_INFLATE_WINDOW)
+            int window_bits;
+
+            if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
+               PNG_OPTION_ON)
+               window_bits = 15;
+
+            else
+               window_bits = 0;
+#        else
+#           define window_bits 0
+#        endif
+#     endif
 
       /* Set this for safety, just in case the previous owner left pointers to
        * memory allocations.
@@ -357,8 +373,7 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner, int window_bits)
 
       if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
       {
-#        if ZLIB_VERNUM < 0x1240
-            PNG_UNUSED(window_bits)
+#        if PNG_ZLIB_VERNUM < 0x1240
             ret = inflateReset(&png_ptr->zstream);
 #        else
             ret = inflateReset2(&png_ptr->zstream, window_bits);
@@ -367,7 +382,7 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner, int window_bits)
 
       else
       {
-#        if ZLIB_VERNUM < 0x1240
+#        if PNG_ZLIB_VERNUM < 0x1240
             ret = inflateInit(&png_ptr->zstream);
 #        else
             ret = inflateInit2(&png_ptr->zstream, window_bits);
@@ -385,6 +400,10 @@ png_inflate_claim(png_structrp png_ptr, png_uint_32 owner, int window_bits)
 
       return ret;
    }
+
+#  ifdef window_bits
+#     undef window_bits
+#  endif
 }
 
 #ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
@@ -557,14 +576,8 @@ png_decompress_chunk(png_structrp png_ptr,
       if (limit < *newlength)
          *newlength = limit;
 
-      /* Now try to claim the stream; the 'warn' setting causes zlib to be told
-       * to use the maximum window size during inflate; this hides errors in the
-       * deflate header window bits value which is used if '0' is passed.  In
-       * fact this only has an effect with zlib versions 1.2.4 and later - see
-       * the comments in png_inflate_claim above.
-       */
-      ret = png_inflate_claim(png_ptr, png_ptr->chunk_name,
-         png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN ? 15 : 0);
+      /* Now try to claim the stream. */
+      ret = png_inflate_claim(png_ptr, png_ptr->chunk_name);
 
       if (ret == Z_OK)
       {
@@ -1334,8 +1347,7 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
          {
             read_length -= keyword_length+2;
 
-            if (png_inflate_claim(png_ptr, png_iCCP,
-               png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN ? 15 : 0) == Z_OK)
+            if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK)
             {
                Byte profile_header[132];
                Byte local_buffer[PNG_INFLATE_BUF_SIZE];
@@ -2734,7 +2746,6 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
 
    png_debug(1, "in png_handle_unknown");
 
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
    /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
     * the bug which meant that setting a non-default behavior for a specific
     * chunk would be ignored (the default was always used unless a user
@@ -2747,15 +2758,14 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
     * function.
     */
 #  ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-#     ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
-         keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
-#     endif
+   keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
 #  endif
 
    /* One of the following methods will read the chunk or skip it (at least one
     * of these is always defined because this is the only way to switch on
     * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
     */
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
 #  ifdef PNG_READ_USER_CHUNKS_SUPPORTED
       /* The user callback takes precedence over the chunk keep value, but the
        * keep value is still required to validate a save of a critical chunk.
@@ -2841,7 +2851,7 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
 
          png_crc_finish(png_ptr, length);
       }
-#  endif
+#  endif /* PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED */
 
 #  ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
       /* Now store the chunk in the chunk list if appropriate, and if the limits
@@ -3642,7 +3652,7 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
 
             for (i = 0; i < row_info->width; i++)
             {
-               png_byte v[8];
+               png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */
                int j;
 
                memcpy(v, sp, pixel_bytes);
@@ -3828,7 +3838,8 @@ png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
 
 static void
 png_init_filter_functions(png_structrp pp)
-   /* This function is called once for every PNG image to set the
+   /* This function is called once for every PNG image (except for PNG images
+    * that only use PNG_FILTER_VALUE_NONE for all rows) to set the
     * implementations required to reverse the filtering of PNG rows.  Reversing
     * the filter is the first transformation performed on the row data.  It is
     * performed in place, therefore an implementation can be selected based on
@@ -3870,10 +3881,13 @@ png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
     * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
     * implementations.  See png_init_filter_functions above.
     */
-   if (pp->read_filter[0] == NULL)
-      png_init_filter_functions(pp);
    if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
+   {
+      if (pp->read_filter[0] == NULL)
+         png_init_filter_functions(pp);
+
       pp->read_filter[filter-1](row_info, row, prev_row);
+   }
 }
 
 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
@@ -4412,7 +4426,7 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
     * IDAT stream has a bogus deflate header window_bits value, but this should
     * not be happening any longer!)
     */
-   if (png_inflate_claim(png_ptr, png_IDAT, 0) != Z_OK)
+   if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK)
       png_error(png_ptr, png_ptr->zstream.msg);
 
    png_ptr->flags |= PNG_FLAG_ROW_INIT;

pngset.c

@@ -238,16 +238,7 @@ png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr,
 
    info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth);
 
-   /* Check for potential overflow */
-   if (width >
-       (PNG_UINT_32_MAX >> 3)      /* 8-byte RRGGBBAA pixels */
-       - 48       /* bigrowbuf hack */
-       - 1        /* filter byte */
-       - 7*8      /* rounding of width to multiple of 8 pixels */
-       - 8)       /* extra max_pixel_depth pad */
-      info_ptr->rowbytes = 0;
-   else
-      info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
+   info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
 }
 
 #ifdef PNG_oFFs_SUPPORTED
@@ -1256,8 +1247,6 @@ png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    /* This API is pretty pointless in 1.6.0 because the location can be set
     * before the call to png_set_unknown_chunks.
-    *
-    * TODO: add a png_app_warning in 1.7
     */
    if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 &&
       chunk < info_ptr->unknown_chunks_num)
@@ -1276,6 +1265,10 @@ png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr,
       info_ptr->unknown_chunks[chunk].location =
          check_location(png_ptr, location);
    }
+
+   /* TODO: make this an error in 1.8 (or maybe it will become one in 1.7!) */
+   else if (png_ptr != NULL)
+      png_app_warning(png_ptr, "unknown chunk index out of range");
 }
 #endif
 

pngtest.c

@@ -1964,4 +1964,4 @@ main(void)
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_7_0beta09 Your_png_h_is_not_version_1_7_0beta09;
+typedef png_libpng_version_1_7_0beta18 Your_png_h_is_not_version_1_7_0beta18;

pngwrite.c

@@ -500,50 +500,50 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
       error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
 #endif /* PNG_USER_MEM_SUPPORTED */
 
-   /* Set the zlib control values to defaults; they can be overridden by the
-    * application after the struct has been created.
-    */
-   png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
+   if (png_ptr != NULL)
+   {
+      /* Set the zlib control values to defaults; they can be overridden by the
+       * application after the struct has been created.
+       */
+      png_ptr->zbuffer_size = PNG_ZBUF_SIZE;
 
-   /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
-    * pngwutil.c defaults it according to whether or not filters will be used,
-    * and ignores this setting.
-    */
-   png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
-   png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
-   png_ptr->zlib_mem_level = 8;
-   png_ptr->zlib_window_bits = 15;
-   png_ptr->zlib_method = 8;
+      /* The 'zlib_strategy' setting is irrelevant because png_default_claim in
+       * pngwutil.c defaults it according to whether or not filters will be
+       * used, and ignores this setting.
+       */
+      png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY;
+      png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION;
+      png_ptr->zlib_mem_level = 8;
+      png_ptr->zlib_window_bits = 15;
+      png_ptr->zlib_method = 8;
 
 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
-   png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
-   png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
-   png_ptr->zlib_text_mem_level = 8;
-   png_ptr->zlib_text_window_bits = 15;
-   png_ptr->zlib_text_method = 8;
+      png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY;
+      png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION;
+      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 */
 
-   /* This is a highly dubious configuration option; by default it is off, but
-    * it may be appropriate for private builds that are testing extensions not
-    * conformant to the current specification, or of applications that must not
-    * fail to write at all costs!
-    */
-#  ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
+      /* This is a highly dubious configuration option; by default it is off,
+       * but it may be appropriate for private builds that are testing
+       * extensions not conformant to the current specification, or of
+       * applications that must not fail to write at all costs!
+       */
+#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
       png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
       /* In stable builds only warn if an application error can be completely
        * handled.
        */
-#  endif
+#endif
 
-   /* 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
-      png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
-#  endif
+      /* 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
+         png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN;
+#endif
 
-   if (png_ptr != NULL)
-   {
       /* TODO: delay this, it can be done in png_init_io() (if the app doesn't
        * do it itself) avoiding setting the default function if it is not
        * required.

projects/vstudio/readme.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.7.0beta09 - April 18, 2013
+libpng version 1.7.0beta18 - September 16, 2013
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 

projects/vstudio/zlib.props

@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.7.0beta09 - April 18, 2013
+ * libpng version 1.7.0beta18 - September 16, 2013
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.7.0beta09 - April 18, 2013
+Makefiles for  libpng version 1.7.0beta18 - September 16, 2013
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng17.so.17.1.7.0beta09)
+                       (gcc, creates libpng17.so.17.1.7.0beta18)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -20,7 +20,7 @@ pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.dec      =>  DEC Alpha UNIX makefile
  makefile.dj2      =>  DJGPP 2 makefile
  makefile.elf      =>  Linux/ELF makefile symbol versioning,
-                       (gcc, creates libpng17.so.17.1.7.0beta09)
+                       (gcc, creates libpng17.so.17.1.7.0beta18)
  makefile.freebsd  =>  FreeBSD makefile
  makefile.gcc      =>  Generic gcc makefile
  makefile.hpgcc    =>  HPUX makefile using gcc
@@ -35,12 +35,12 @@ 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 libpng17.so.17.1.7.0beta09)
+                       creates libpng17.so.17.1.7.0beta18)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng17.so.17.1.7.0beta09)
+                       creates libpng17.so.17.1.7.0beta18)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng17.so.17.1.7.0beta09)
+                       creates libpng17.so.17.1.7.0beta18)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile

scripts/def.dfn

@@ -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 1.7.0beta09"
+PNG_DFN ";Version 1.7.0beta18"
 
 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\
         PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"

scripts/libpng-config-head.in

@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.7.0beta09
+version=1.7.0beta18
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@/libpng17
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.7.0beta09
+Version: 1.7.0beta18
 Libs: -L${libdir} -lpng17
 Cflags: -I${includedir}

scripts/makefile.ne12bsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng17
 
 LIB=	png17
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.7.0beta09
+SHLIB_MINOR=	1.7.0beta18
 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=	17
-SHLIB_MINOR=	1.7.0beta09
+SHLIB_MINOR=	1.7.0beta18
 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=	17
-SHLIB_MINOR=	1.7.0beta09
+SHLIB_MINOR=	1.7.0beta18
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \

scripts/pnglibconf.dfa

@@ -126,7 +126,7 @@ logunsupported = 1
 #
 # If you create a private DLL you need to define the following
 # macros in the file 'pngusr.h' and set -DPNG_USER_CONFIG for
-# compilation (i.e. in CFLAGS.)
+# compilation (i.e. in CPPFLAGS.)
 # #define PNG_USER_PRIVATEBUILD \
 #     <Describes by whom and why this version of the DLL was built>
 #  e.g. #define PNG_USER_PRIVATEBUILD "Build by MyCompany for xyz reasons."
@@ -165,12 +165,6 @@ logunsupported = 1
 @#  endif
 @#endif
 
-# This changes the default for the ARM NEON optimizations according to
-# __ARM_NEON__
-@#ifdef __ARM_NEON__
-@#  define PNG_ARM_NEON_SUPPORTED
-@#endif
-
 # IN DEVELOPMENT
 # These are currently experimental features; define them if you want (NOTE:
 # experimental options must be disabled before they are defined in this file!)
@@ -222,31 +216,41 @@ setting ZLIB_HEADER default <zlib.h>
 # include the file too, so that the defaults below are known
 @#  include <zlib.h>
 
-# This setting allows a hardware or configuration specific filter optimization
-# function to be specified, the argument is the name of the filter initializaion
-# function to use.
-
-setting FILTER_OPTIMIZATIONS
-
 # 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)
 option SET_OPTION disabled
 
-# These options are specific to the ARM NEON hardware optimizations:
+# These options are specific to the ARM NEON hardware optimizations.  At present
+# these optimizations depend on GCC specific pre-processing of an assembler (.S)
+# file so they probably won't work with other compilers.
 #
-# ARM_NEON: the optimization itself
-# ARM_NEON_API: allow the optimization to be switched on with png_set_hardware
-# ARM_NEON_CHECK: compile a run-time check to see if Neon extensions are
-#                 supported, this is poorly supported and deprectated - use the
-#                 png_set_hardware API.
-option ARM_NEON disabled,
-   sets FILTER_OPTIMIZATIONS png_init_filter_functions_neon
-option ARM_NEON_API disabled enables SET_OPTION ARM_NEON
-option ARM_NEON_CHECK disabled enables ARM_NEON
+# ARM_NEON_OPT: unset: check at compile time (__ARM_NEON__ must be defined by
+#                      the compiler, typically as a result of specifying
+#                      CC="gcc -mfpu=neon".)
+#                   0: disable (even if the CPU has a NEON FPU.)
+#                   1: check at run time (via ARM_NEON_{API,CHECK})
+#                   2: switch on unconditionally (inadvisable - instead pass
+#                      -mfpu=neon to GCC in CC)
+#           When building libpng avoid using any setting other than '0'; '1' is
+#           set automatically when either 'API' or 'CHECK' are configured in,
+#           '2' should not be necessary as -mfpu=neon will achieve the same
+#           effect as well as applying NEON optimizations to the rest of the
+#           libpng code.
+#           NOTE: any setting other than '0' requires ALIGNED_MEMORY
+# 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.
+setting ARM_NEON_OPT
+option ARM_NEON_API disabled requires ALIGNED_MEMORY enables SET_OPTION,
+   sets ARM_NEON_OPT 1
+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
@@ -255,6 +259,7 @@ option ARM_NEON_CHECK disabled enables ARM_NEON
 # The TEXT values are the defaults when writing compressed text (all forms)
 
 # The '@' here means to substitute the value when pnglibconf.h is built
+setting ZLIB_VERNUM default @ZLIB_VERNUM
 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?
@@ -425,7 +430,7 @@ option SET_USER_LIMITS requires USER_LIMITS
 # to libpng 1.6; the new interfaces in 1.6 will take several years to become
 # popular.
 
-option READ enables READ_INTERLACING
+option READ enables READ_INTERLACING SET_OPTION
 
 # Disabling READ_16BIT does not disable reading 16-bit PNG files, but it
 # forces them to be chopped down to 8-bit, and disables any 16-bit

scripts/pnglibconf.h.prebuilt

@@ -1,8 +1,8 @@
-/* libpng 1.7.0beta09 STANDARD API DEFINITION */
+/* libpng 1.7.0beta18 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.7.0beta09 - April 18, 2013 */
+/* Libpng version 1.7.0beta18 - September 16, 2013 */
 
 /* Copyright (c) 1998-2013 Glenn Randers-Pehrson */
 
@@ -20,7 +20,6 @@
 #define PNG_ALIGNED_MEMORY_SUPPORTED
 /*#undef PNG_ARM_NEON_API_SUPPORTED*/
 /*#undef PNG_ARM_NEON_CHECK_SUPPORTED*/
-/*#undef PNG_ARM_NEON_SUPPORTED*/
 #define PNG_BENIGN_ERRORS_SUPPORTED
 #define PNG_BENIGN_READ_ERRORS_SUPPORTED
 /*#undef PNG_BENIGN_WRITE_ERRORS_SUPPORTED*/
@@ -103,7 +102,7 @@
 #define PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SEQUENTIAL_READ_SUPPORTED
 #define PNG_SETJMP_SUPPORTED
-/*#undef PNG_SET_OPTION_SUPPORTED*/
+#define PNG_SET_OPTION_SUPPORTED
 #define PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
 #define PNG_SET_USER_LIMITS_SUPPORTED
 #define PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
@@ -200,6 +199,7 @@
 #define PNG_TEXT_Z_DEFAULT_COMPRESSION (-1)
 #define PNG_TEXT_Z_DEFAULT_STRATEGY 0
 #define PNG_WEIGHT_SHIFT 8
+#define PNG_ZLIB_VERNUM 0 /* unknown */
 #define PNG_ZBUF_SIZE 8192
 #define PNG_ZLIB_HEADER <zlib.h>
 #define PNG_Z_DEFAULT_COMPRESSION (-1)

scripts/symbols.def

@@ -1,4 +1,4 @@
-;Version 1.7.0beta09
+;Version 1.7.0beta18
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng