[libpng16] Imported from libpng-1.6.8.tar

Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
to '"%s" m' to improve portability among compilers.

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.6.4 - September 12, 2013
+Libpng 1.6.8 - December 19, 2013
 
 This is a public release of libpng, intended for use in production codes.
 
@@ -8,28 +8,50 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   libpng-1.6.4.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.4.tar.gz
+   libpng-1.6.8.tar.xz (LZMA-compressed, recommended)
+   libpng-1.6.8.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lpng164.7z  (LZMA-compressed, recommended)
-   lpng164.zip
+   lpng168.7z  (LZMA-compressed, recommended)
+   lpng168.zip
 
 Other information:
 
-   libpng-1.6.4-README.txt
-   libpng-1.6.4-LICENSE.txt
+   libpng-1.6.8-README.txt
+   libpng-1.6.8-LICENSE.txt
    Gnupg/*.asc (PGP armored detached signatures)
 
-Changes since the last public release (1.6.3):
-  Added information about png_set_options() to the manual.
-  Delay calling png_init_filter_functions() until a row with nonzero filter
-    is found.
-  Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
-    prototype, definition, and usage.  Made it depend on
-    PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
+Changes since the last public release (1.6.7):
+  Changed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpread.c to
+    #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED to be consistent with
+    what is in pngpriv.h.
+  Moved prototype for png_handle_unknown() in pngpriv.h outside of
+    the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
+  Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
+  Conditionally compile some unused functions reported by -Wall in
+    pngminim.
+  Fixed 'minimal' builds. Various obviously useful minimal configurations
+    don't build because of missing contrib/libtests test programs and
+    overly complex dependencies in scripts/pnglibconf.dfa. This change
+    adds contrib/conftest/*.dfa files that can be used in automatic build
+    scripts to ensure that these configurations continue to build.
+  Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder.
+  Fixed pngvalid 'fail' function declaration on the Intel C Compiler.
+    This reverts to the previous 'static' implementation and works round
+    the 'unused static function' warning by using PNG_UNUSED().
+  Removed or marked PNG_UNUSED some harmless "dead assignments" reported
+    by clang scan-build.
+  Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
+    to '"%s" m' to improve portability among compilers.
+  Changed png_free_default() to free() in pngtest.c
+  Tidied up pngfix inits and fixed pngtest no-write builds.
+  Handle zero-length PLTE chunk or NULL palette with png_error()
+    instead of png_chunk_report(), which by default issues a warning
+    rather than an error, leading to later reading from a NULL pointer
+    (png_ptr->palette) in png_do_expand_palette(). This is CVE-2013-6954
+    and VU#650142.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -4634,6 +4634,121 @@ Version 1.6.4rc01 [September 5, 2013]
 Version 1.6.4 [September 12, 2013]
   No changes.
 
+Version 1.6.5 [September 14, 2013]
+  Removed two stray lines of code from arm/arm_init.c.
+
+Version 1.6.6 [September 16, 2013]
+  Removed two stray lines of code from arm/arm_init.c, again.
+
+Version 1.6.7beta01 [September 30, 2013]
+  Revised unknown chunk code to correct several bugs in the NO_SAVE_/NO_WRITE
+    combination
+  Allow HANDLE_AS_UNKNOWN to work when other options are configured off. Also
+    fixed the pngminim makefiles to work when $(MAKEFLAGS) contains stuff
+    which terminates the make options (as by default in recent versions of
+    Gentoo).
+  Avoid up-cast warnings in pngvalid.c. On ARM the alignment requirements of
+    png_modifier are greater than that of png_store and as a consequence
+    compilation of pngvalid.c results in a warning about increased alignment
+    requirements because of the bare cast to (png_modifier*). The code is safe,
+    because the pointer is known to point to a stack allocated png_modifier,
+    but this change avoids the warning.
+  Fixed default behavior of ARM_NEON_API. If the ARM NEON API option was
+    compiled without the CHECK option it defaulted to on, not off.
+  Check user callback behavior in pngunknown.c. Previous versions compiled
+    if SAVE_UNKNOWN was not available but did nothing since the callback
+    was never implemented.
+  Merged pngunknown.c with 1.7 version and back ported 1.7 improvements/fixes
+
+Version 1.6.7beta02 [October 12, 2013]
+  Made changes for compatibility with automake 1.14:
+    1) Added the 'compile' program to the list of programs that must be cleaned
+       in autogen.sh
+    2) Added 'subdir-objects' which causes .c files in sub-directories to be
+       compiled such that the corresponding .o files are also in the
+       sub-directory.  This is because automake 1.14 warns that the
+       current behavior of compiling to the top level directory may be removed
+       in the future.
+    3) Updated dependencies on pnglibconf.h to match the new .o locations and
+       added all the files in contrib/libtests and contrib/tools that depend
+       on pnglibconf.h
+    4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended
+       way of handling the dependencies of sources that are machine generated;
+       unfortunately it only works if the user does 'make all' or 'make check',
+       so the dependencies (3) are still required.
+  Cleaned up (char*) casts of zlib messages. The latest version of the Intel C
+    compiler complains about casting a string literal as (char*), so copied the
+    treatment of z_const from the library code into pngfix.c
+  Simplified error message code in pngunknown. The simplification has the
+    useful side effect of avoiding a bogus warning generated by the latest
+    version of the Intel C compiler (it objects to
+    condition ? string-literal : string-literal).
+  Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
+    removing the 1.14 'compile' script but never checking for it.
+
+Version 1.6.7beta03 [October 19, 2013]
+  Added ARMv8 support (James Yu <james.yu at linaro.org>).  Added file
+    arm/filter_neon_intrinsics.c; enable with -mfpu=neon.
+  Revised pngvalid to generate size images with as many filters as it can
+    manage, limited by the number of rows.
+  Cleaned up ARM NEON compilation handling. The tests are now in pngpriv.h
+    and detect the broken GCC compilers.
+
+Version 1.6.7beta04 [October 26, 2013]
+  Allow clang derived from older GCC versions to use ARM intrinsics. This
+    causes all clang builds that use -mfpu=neon to use the intrinsics code,
+    not the assembler code.  This has only been tested on iOS 7. It may be
+    necessary to exclude some earlier clang versions but this seems unlikely.
+  Changed NEON implementation selection mechanism. This allows assembler
+    or intrinsics to be turned on at compile time during the build by defining
+    PNG_ARM_NEON_IMPLEMENTATION to the correct value (2 or 1).  This macro
+    is undefined by default and the build type is selected in pngpriv.h.
+
+Version 1.6.7rc01 [November 2, 2013]
+  No changes.
+
+Version 1.6.7rc02 [November 7, 2013]
+  Fixed #include in filter_neon_intrinsics.c and ctype macros. The ctype char
+    checking macros take an unsigned char argument, not a signed char.
+
+Version 1.6.7 [November 14, 2013]
+  No changes.
+
+Version 1.6.8beta01 [November 24, 2013]
+  Moved prototype for png_handle_unknown() in pngpriv.h outside of
+    the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
+  Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
+  Conditionally compile some unused functions reported by -Wall in
+    pngminim.
+  Fixed 'minimal' builds. Various obviously useful minimal configurations
+    don't build because of missing contrib/libtests test programs and
+    overly complex dependencies in scripts/pnglibconf.dfa. This change
+    adds contrib/conftest/*.dfa files that can be used in automatic build
+    scripts to ensure that these configurations continue to build.
+  Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder.
+  Fixed pngvalid 'fail' function declaration on the Intel C Compiler.
+    This reverts to the previous 'static' implementation and works round
+    the 'unused static function' warning by using PNG_UNUSED().
+
+Version 1.6.8beta02 [November 30, 2013]
+  Removed or marked PNG_UNUSED some harmless "dead assignments" reported
+    by clang scan-build.
+  Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
+    to '"%s" m' to improve portability among compilers.
+  Changed png_free_default() to free() in pngtest.c
+
+Version 1.6.8rc01 [December 12, 2013]
+  Tidied up pngfix inits and fixed pngtest no-write builds.
+
+Version 1.6.8rc02 [December 14, 2013]
+  Handle zero-length PLTE chunk or NULL palette with png_error()
+    instead of png_chunk_report(), which by default issues a warning
+    rather than an error, leading to later reading from a NULL pointer
+    (png_ptr->palette) in png_do_expand_palette(). This is CVE-2013-6954
+    and VU#650142.
+
+Version 1.6.8 [December 19, 2013]
+
 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

@@ -16,7 +16,7 @@ enable_testing()
 
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 4)
+set(PNGLIB_RELEASE 8)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
@@ -252,7 +252,7 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.4
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.8
     VERSION 16.${PNGLIB_RELEASE}.0
     SOVERSION 16
     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 1.6.4, September 12, 2013, are
+libpng versions 1.2.6, August 15, 2004, through 1.6.8, December 19, 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
-September 12, 2013
+December 19, 2013

Makefile.am

@@ -12,6 +12,16 @@ check_PROGRAMS= pngtest pngunknown pngstest pngvalid
 # Utilities - installed
 bin_PROGRAMS= pngfix png-fix-itxt
 
+# This ensures that pnglibconf.h gets built at the start of 'make all' or
+# 'make check', but it does not add dependencies to the individual programs,
+# this is done below.
+#
+# IMPORTANT: always add the object modules of new programs to the list below
+# because otherwise the sequence 'configure; make new-program' will *sometimes*
+# result in the installed (system) pnglibconf.h being used and the result is
+# always wrong and always very confusing.
+BUILT_SOURCES = pnglibconf.h
+
 pngtest_SOURCES = pngtest.c
 pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
@@ -71,8 +81,8 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
 	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
 
 if PNG_ARM_NEON
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
-	arm/filter_neon.S
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
+	arm/filter_neon.S arm/filter_neon_intrinsics.c
 endif
 
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
@@ -194,9 +204,21 @@ $(srcdir)/scripts/pnglibconf.h.prebuilt:
 
 # 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.)
-pngstest.o pngvalid.o pngtest.o pngunknown.o timepng.o: pnglibconf.h
-pngfix.o png-fix-itxt.o: pnglibconf.h
+# 'make test' is the first thing the user does.)  Only files which include
+# one of the png source files (typically png.h or pngpriv.h) need to be listed
+# here:
+pngtest.o: pnglibconf.h
+
+contrib/libtests/makepng.o: pnglibconf.h
+contrib/libtests/pngstest.o: pnglibconf.h
+contrib/libtests/pngunknown.o: pnglibconf.h
+contrib/libtests/pngvalid.o: pnglibconf.h
+contrib/libtests/readpng.o: pnglibconf.h
+contrib/libtests/tarith.o: pnglibconf.h
+contrib/libtests/timepng.o: pnglibconf.h
+
+contrib/tools/makesRGB.o: pnglibconf.h
+contrib/tools/pngfix.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
@@ -302,3 +324,8 @@ uninstall-hook:
 	rm -f '$(DESTDIR)$(libdir)/libpng.sl'
 	rm -f '$(DESTDIR)$(libdir)/libpng.dylib'
 	rm -f '$(DESTDIR)$(libdir)/libpng.dll.a'
+
+# The following addition ensures that 'make all' always builds the test programs
+# too.  It used to, but some change either in libpng or configure stopped this
+# working.
+all-am: $(check_PROGRAMS)

README

@@ -1,4 +1,4 @@
-README for libpng version 1.6.4 - September 12, 2013 (shared library 16.0)
+README for libpng version 1.6.8 - December 19, 2013 (shared library 16.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.

arm/arm_init.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.5.17 [July 18, 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
@@ -17,8 +17,6 @@
 #include "../pngpriv.h"
 
 #ifdef PNG_READ_SUPPORTED
-  if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
-     PNG_OPTION_ON)
 #if PNG_ARM_NEON_OPT > 0
 #ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
 #include <signal.h> /* for sig_atomic_t */
@@ -156,6 +154,16 @@ png_have_neon(png_structp png_ptr)
 void
 png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
 {
+   /* The switch statement is compiled in for ARM_NEON_API, the call to
+    * png_have_neon is compiled in for ARM_NEON_CHECK.  If both are defined
+    * the check is only performed if the API has not set the NEON option on
+    * or off explicitly.  In this case the check controls what happens.
+    *
+    * If the CHECK is not compiled in and the option is UNSET the behavior prior
+    * to 1.6.7 was to use the NEON code - this was a bug caused by having the
+    * wrong order of the 'ON' and 'default' cases.  UNSET now defaults to OFF,
+    * as documented in png.h
+    */
 #ifdef PNG_ARM_NEON_API_SUPPORTED
    switch ((pp->options >> PNG_ARM_NEON) & 3)
    {
@@ -180,13 +188,14 @@ png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
          break;
 #endif
 #endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
 #ifdef PNG_ARM_NEON_API_SUPPORTED
+      default: /* OFF or INVALID */
+         return;
+
       case PNG_OPTION_ON:
          /* Option turned on */
          break;
-
-      default: /* OFF or INVALID */
-         return;
    }
 #endif
 

arm/filter_neon.S

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.5.17 [July 18, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -11,7 +11,8 @@
  */
 
 /* This is required to get the symbol renames, which are #defines, and also
- * includes the definition (or not) of PNG_ARM_NEON_OPT.
+ * includes the definition (or not) of PNG_ARM_NEON_OPT and
+ * PNG_ARM_NEON_IMPLEMENTATION.
  */
 #define PNG_VERSION_INFO_ONLY
 #include "../pngpriv.h"
@@ -20,6 +21,13 @@
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
 
+/* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for
+ * ARM64).  The code in arm/filter_neon_intrinsics.c supports ARM64, however it
+ * only works if -mfpu=neon is specified on the GCC command line.  See pngpriv.h
+ * for the logic which sets PNG_USE_ARM_NEON_ASM:
+ */
+#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
+
 #ifdef PNG_READ_SUPPORTED
 #if PNG_ARM_NEON_OPT > 0
 
@@ -235,3 +243,4 @@ func    png_read_filter_row_paeth3_neon, export=1
 endfunc
 #endif /* PNG_ARM_NEON_OPT > 0 */
 #endif /* PNG_READ_SUPPORTED */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */

arm/filter_neon_intrinsics.c

@@ -0,0 +1,372 @@
+
+/* filter_neon_intrinsics.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2013 Glenn Randers-Pehrson
+ * Written by James Yu <james.yu at linaro.org>, October 2013.
+ * Based on filter_neon.S, written by Mans Rullgard, 2011.
+ *
+ * Last changed in libpng 1.6.8 [December 19, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+/* This code requires -mfpu=neon on the command line: */
+#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
+
+#include <arm_neon.h>
+
+/* libpng row pointers are not necessarily aligned to any particular boundary,
+ * however this code will only work with appropriate alignment.  arm/arm_init.c
+ * checks for this (and will not compile unless it is done), this code uses
+ * variants of png_aligncast to avoid compiler warnings.
+ */
+#define png_ptr(type,pointer) png_aligncast(type *,pointer)
+#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer)
+
+/* The following relies on a variable 'temp_pointer' being declared with type
+ * 'type'.  This is written this way just to hide the GCC strict aliasing
+ * warning; note that the code is safe because there never is an alias between
+ * the input and output pointers.
+ */
+#define png_ldr(type,pointer)\
+   (temp_pointer = png_ptr(type,pointer), *temp_pointer)
+
+#ifdef PNG_READ_SUPPORTED
+#if PNG_ARM_NEON_OPT > 0
+
+void
+png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint8x16_t qrp, qpp;
+
+      qrp = vld1q_u8(rp);
+      qpp = vld1q_u8(pp);
+      qrp = vaddq_u8(qrp, qpp);
+      vst1q_u8(rp, qrp);
+   }
+}
+
+void
+png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp = vld1q_u8(rp);
+   uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp);
+   uint8x8x2_t vrp = *vrpt;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop;)
+   {
+      uint8x8_t vtmp1, vtmp2;
+      uint32x2_t *temp_pointer;
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vadd_u8(vdest.val[0], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vdest.val[2] = vadd_u8(vdest.val[1], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t, &vtmp);
+      vrp = *vrpt;
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+
+   PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16)
+   {
+      uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      uint8x8x4_t vrp = *vrpt;
+      uint32x2x4_t *temp_pointer;
+
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]);
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+
+   PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t *vrpt;
+   uint8x8x2_t vrp;
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrpt = png_ptr(uint8x8x2_t,&vtmp);
+   vrp = *vrpt;
+
+   for (; rp < rp_stop; pp += 12)
+   {
+      uint8x8_t vtmp1, vtmp2, vtmp3;
+
+      uint8x8x2_t *vppt;
+      uint8x8x2_t vpp;
+
+      uint32x2_t *temp_pointer;
+
+      vtmp = vld1q_u8(pp);
+      vppt = png_ptr(uint8x8x2_t,&vtmp);
+      vpp = *vppt;
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t,&vtmp);
+      vrp = *vrpt;
+
+      vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp3);
+
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint32x2x4_t vtmp;
+      uint8x8x4_t *vrpt, *vppt;
+      uint8x8x4_t vrp, vpp;
+      uint32x2x4_t *temp_pointer;
+
+      vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      vrp = *vrpt;
+      vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+      vppt = png_ptr(uint8x8x4_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+}
+
+static uint8x8_t
+paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c)
+{
+   uint8x8_t d, e;
+   uint16x8_t p1, pa, pb, pc;
+
+   p1 = vaddl_u8(a, b); /* a + b */
+   pc = vaddl_u8(c, c); /* c * 2 */
+   pa = vabdl_u8(b, c); /* pa */
+   pb = vabdl_u8(a, c); /* pb */
+   pc = vabdq_u16(p1, pc); /* pc */
+
+   p1 = vcleq_u16(pa, pb); /* pa <= pb */
+   pa = vcleq_u16(pa, pc); /* pa <= pc */
+   pb = vcleq_u16(pb, pc); /* pb <= pc */
+
+   p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */
+
+   d = vmovn_u16(pb);
+   e = vmovn_u16(p1);
+
+   d = vbsl_u8(d, b, c);
+   e = vbsl_u8(e, a, d);
+
+   return e;
+}
+
+void
+png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t *vrpt;
+   uint8x8x2_t vrp;
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrpt = png_ptr(uint8x8x2_t,&vtmp);
+   vrp = *vrpt;
+
+   for (; rp < rp_stop; pp += 12)
+   {
+      uint8x8x2_t *vppt;
+      uint8x8x2_t vpp;
+      uint8x8_t vtmp1, vtmp2, vtmp3;
+      uint32x2_t *temp_pointer;
+
+      vtmp = vld1q_u8(pp);
+      vppt = png_ptr(uint8x8x2_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t,&vtmp);
+      vrp = *vrpt;
+
+      vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vlast = vtmp2;
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint32x2x4_t vtmp;
+      uint8x8x4_t *vrpt, *vppt;
+      uint8x8x4_t vrp, vpp;
+      uint32x2x4_t *temp_pointer;
+
+      vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      vrp = *vrpt;
+      vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+      vppt = png_ptr(uint8x8x4_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vlast = vpp.val[3];
+
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+}
+
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_READ_SUPPORTED */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */

autogen.sh

@@ -9,15 +9,15 @@
 #
 # For regular ("tarball") distributions all the files should exist.  We do not
 # want them to be updated *under any circumstances*.  It should never be
-# necessary to rune autogen.sh because ./configure --enable-maintainer-mode says
-# what to do if Makeile.am or configure.ac are changed.
+# necessary to run autogen.sh because ./configure --enable-maintainer-mode says
+# what to do if Makefile.am or configure.ac are changed.
 #
 # It is *probably* OK to update the files on a GIT checkout, because they have
 # come from the local tools, but leave that to the user who is assumed to know
 # whether it is ok or required.
 #
 # This script is intended to work without arguments, there are, however, hidden
-# arguments for (a) use while testing the script and (b) to fix up systems that
+# arguments (a) for use while testing the script and (b) to fix up systems that
 # have been broken.  If (b) is required the script prompts for the correct
 # options.  For this reason the options are *NOT* documented in the help; this
 # is deliberate; UTSL.
@@ -76,6 +76,10 @@ done
 libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in\
    config.sub configure depcomp install-sh ltmain.sh missing test-driver"
 #
+# Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
+# versions than those required by configure.ac):
+libpng_autotools_extra="compile"
+#
 # These are separate because 'maintainer-clean' does not remove them.
 libpng_libtool_files="scripts/libtool.m4 scripts/ltoptions.m4\
    scripts/ltsugar.m4 scripts/ltversion.m4 scripts/lt~obsolete.m4"
@@ -94,6 +98,7 @@ libpng_configure_dirs=".deps"
 # of Makefile.  These functions do the two bits of cleaning.
 clean_autotools(){
    rm -rf $libpng_autotools_files $libpng_libtool_files $libpng_autotools_dirs
+   rm -rf $libpng_autotools_extra
 }
 
 clean_configure(){
@@ -198,7 +203,7 @@ case "$mode" in
          echo "  You can run autoreconf yourself if you don't like maintainer"
          echo "  mode and you can also just run autoreconf -f -i to initialize"
          echo "  everything in the first place; this script is only for"
-         echo "  compatiblity with prior releases."
+         echo "  compatibility with prior releases."
          exit 1
       else
          exec >&2

configure.ac

@@ -18,7 +18,7 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.4],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.8],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -27,7 +27,7 @@ AC_CONFIG_MACRO_DIR([scripts])
 # dist-xz requires automake 1.11 or later
 # 1.12.2 fixes a security issue in 1.11.2 and 1.12.1
 # 1.13 is required for parallel tests
-AM_INIT_AUTOMAKE([1.13 foreign dist-xz color-tests silent-rules])
+AM_INIT_AUTOMAKE([1.13 foreign dist-xz color-tests silent-rules subdir-objects])
 # The following line causes --disable-maintainer-mode to be the default to
 # configure, this is necessary because libpng distributions cannot rely on the
 # time stamps of the autotools generated files being correct
@@ -39,10 +39,10 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.6.4
+PNGLIB_VERSION=1.6.8
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=4
+PNGLIB_RELEASE=8
 
 dnl End of version number stuff
 

contrib/conftest/README

@@ -0,0 +1,49 @@
+This directory contains test configuration files, currently always '.dfa' files
+intended to be used in the build by setting the make macro DFA_XTRA to the name
+of the file.
+
+These files are used in release validation of the 'configure' builds of libpng
+by building 'make check', or 'make all-am' for cross-builds, with each .dfa
+file.
+
+The files in this directory may change between minor releases, however
+contributions describing specific builds of libpng are welcomed.  There is no
+guarantee that libpng will continue to build with such configurations; support
+for given configurations can be, and has been, dropped between successive minor
+releases.  However if a .dfa file describing a configuration is not in this
+directory it is very unlikely that it will be tested before a minor release!
+
+You can use these .dfa files as the basis of new configurations.  Files in this
+directory should not have any use restrictions or restrictive licenses.
+
+This directory is not included in the .zip and .7z distributions, which do
+not contain 'configure' scripts.
+
+DOCUMENTATION
+=============
+
+Examples:
+   ${srcdir}/pngusr.dfa
+   ${srcdir}/contrib/pngminim/*/pngusr.dfa
+
+Documentation of the options:
+   ${srcdir}/scripts/pnglibconf.dfa
+
+Documentation of the file format:
+   ${srcdir}/scripts/options.awk
+
+FILE NAMING
+===========
+
+File names in this directory may NOT contain any of the five characters:
+
+   - , + * ?
+
+Neither may they contain any space character.
+
+While other characters may be used it is strongly suggested that file names be
+limited to lower case Latiin alphabetic characters (a-z), digits (0-9) and, if
+necessary the underscore (_) character.  File names should be about 8 characters
+long (excluding the .dfa extension).  Submitted .dfa files should have names
+between 7 and 16 characters long, shorter names (6 characters or less) are
+reserved for standard tests.

contrib/conftest/read.dfa

@@ -0,0 +1,58 @@
+# read.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with basic read support.  This enables the lowest level libpng
+# read API - the one where the calling code has to use a loop to read each row.
+# At present this is the API used by most programs.
+#
+# Support is enabled only for those chunks and transformations that are
+# typically required - others can be added easily.
+#
+
+everything = off
+
+# The sequential read code is enabled here; the progressive code can be used
+# instead but there is no point enabling both.
+
+option SEQUENTIAL_READ on
+
+# Likewise it is pointless enabling both fixed and floating point APIs.  Choose
+# one or the other for both the API and the internal math.
+
+#Fixed point:
+#option FIXED_POINT on
+#option FLOATING_ARITHMETIC off
+
+#Floating point:
+option FLOATING_POINT on
+option FLOATING_ARITHMETIC on
+
+# Basic error handling, IO and user memory support.  The latter allows the
+# application program to provide its own implementations of 'malloc' and 'free'.
+option SETJMP on
+option STDIO on
+option USER_MEM on
+
+# To read the full set of PNG images correctly interlace, transparency and
+# 16-bit support is required.  The application can implement interlace itself,
+# but very few do and it's no longer possible to disable it when READ is
+# enabled.
+option READ_tRNS on
+option READ_16BIT on
+
+# Everything else is application dependent.  This file assumes the app handles
+# all the native PNG bit layouts, so it doesn't need any of layout change
+# transforms, but needs libpng to perform gamma correction.  It doesn't do any
+# colorspace stuff and ignores the 'significant bit' information.
+#
+# If your app always expands the image to a limited set of bit layouts you
+# probably want to consider using the simplified API instead of the low level
+# one - see png.h and s_read.dfa.
+option READ_GAMMA on

contrib/conftest/s_read.dfa

@@ -0,0 +1,35 @@
+# s_read.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with simplified read support (only).  This builds a minimal
+# libpng able to read all PNG formats and convert them into a small number of
+# well understood memory formats.
+#
+
+everything = off
+
+option SIMPLIFIED_READ on
+
+# It isn't necessary to chose fixed or floating point for the APIs because the
+# simplified API doesn't need fixed or floating point numbers.  It is necessary
+# to chose an internal math implementation.  The default (because of 'everything
+# = off') is fixed point - turn the floating point implementation on if you have
+# hardware floating point or prefer your software floating point implementation.
+option FLOATING_ARITHMETIC on
+
+# This is not strictly necessary, but without it the message strings in the API
+# will not be filled in
+option ERROR_TEXT on
+
+# Switching these options on enables the 'AFIRST' and 'BGR' formats - you don't
+# need this if you don't use them, they just allow the in-memory layout to be
+# changed to match common hardware formats.
+option SIMPLIFIED_READ_AFIRST on
+option SIMPLIFIED_READ_BGR on

contrib/conftest/s_write.dfa

@@ -0,0 +1,33 @@
+# s_write.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with (just) simplified write support
+#
+
+everything = off
+
+option SIMPLIFIED_WRITE on
+
+# It isn't necessary to chose fixed or floating point for the APIs because the
+# simplified API doesn't need fixed or floating point numbers.  It is necessary
+# to chose an internal math implementation.  The default (because of 'everything
+# = off') is fixed point - turn the floating point implementation on if you have
+# hardware floating point or prefer your software floating point implementation.
+option FLOATING_ARITHMETIC on
+
+# This is not strictly necessary, but without it the message strings in the API
+# will not be filled in
+option ERROR_TEXT on
+
+# Switching these options on enables the 'AFIRST' and 'BGR' formats - you don't
+# need this if you don't use them, they just allow the in-memory layout to be
+# changed to match common hardware formats.
+option SIMPLIFIED_WRITE_AFIRST on
+option SIMPLIFIED_WRITE_BGR on

contrib/conftest/simple.dfa

@@ -0,0 +1,36 @@
+# simple.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with just the simplified APIs (read and write).
+#
+
+everything = off
+
+option SIMPLIFIED_WRITE on
+option SIMPLIFIED_READ on
+
+# It isn't necessary to chose fixed or floating point for the APIs because the
+# simplified API doesn't need fixed or floating point numbers.  It is necessary
+# to chose an internal math implementation.  The default (because of 'everything
+# = off') is fixed point - turn the floating point implementation on if you have
+# hardware floating point or prefer your software floating point implementation.
+option FLOATING_ARITHMETIC on
+
+# This is not strictly necessary, but without it the message strings in the API
+# will not be filled in
+option ERROR_TEXT on
+
+# Switching these options on enables the 'AFIRST' and 'BGR' formats - you don't
+# need this if you don't use them, they just allow the in-memory layout to be
+# changed to match common hardware formats.
+option SIMPLIFIED_READ_AFIRST on
+option SIMPLIFIED_READ_BGR on
+option SIMPLIFIED_WRITE_AFIRST on
+option SIMPLIFIED_WRITE_BGR on

contrib/conftest/write.dfa

@@ -0,0 +1,45 @@
+# write.dfa
+#  Build time configuration of libpng
+#
+# Author: John Bowler
+# Copyright: (c) John Bowler, 2013
+# Usage rights:
+#  To the extent possible under law, the author has waived all copyright and
+#  related or neighboring rights to this work.  This work is published from:
+#  United States.
+#
+# Build libpng with no read support and minimal write support.
+#
+
+everything = off
+
+# Switch on the write code - this makes a minimalist encoder
+
+option WRITE on
+
+# Choose fixed or floating point APIs and arithmetic.  The choices are
+# independent but normally they will match.  It is typically better to use the
+# floating point if you have floating point hardware.  If you don't know, or
+# (perhaps) to make libpng smaller used fixed point throughout.
+
+#Fixed point:
+#option FIXED_POINT on
+#option FLOATING_ARITHMETIC off
+
+#Floating point:
+option FLOATING_POINT on
+option FLOATING_ARITHMETIC on
+
+# Basic error handling, IO and user memory support.  The latter allows the
+# application program to provide its own implementations of 'malloc' and 'free'.
+option SETJMP on
+option STDIO on
+option USER_MEM on
+
+# Everything else is optional.  Unlike the read code in libpng the write code
+# does not need to deal with arbitrary formats, so only add support for things
+# you really do write!  For example you might only write sRGB images, sometimes
+# with transparency and never write 16 bit images, so:
+option WRITE_sRGB on
+option WRITE_tRNS on
+#option WRITE_16BIT off (this is the default with 'everything = off')

contrib/libtests/pngstest.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2013 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -517,14 +517,23 @@ static void format_default(format_list *pf, int redundant)
 
       for (f=0; f<FORMAT_COUNT; ++f)
       {
-         /* Eliminate redundant settings. */
-         /* BGR is meaningless if no color: */
-         if ((f & PNG_FORMAT_FLAG_COLOR) == 0 && (f & PNG_FORMAT_FLAG_BGR) != 0)
+         /* Eliminate redundant and unsupported settings. */
+#        ifdef PNG_FORMAT_BGR_SUPPORTED
+            /* BGR is meaningless if no color: */
+            if ((f & PNG_FORMAT_FLAG_COLOR) == 0 &&
+               (f & PNG_FORMAT_FLAG_BGR) != 0)
+#        else
+            if ((f & 0x10U/*HACK: fixed value*/) != 0)
+#        endif
             continue;
 
          /* AFIRST is meaningless if no alpha: */
-         if ((f & PNG_FORMAT_FLAG_ALPHA) == 0 &&
-            (f & PNG_FORMAT_FLAG_AFIRST) != 0)
+#        ifdef PNG_FORMAT_AFIRST_SUPPORTED
+            if ((f & PNG_FORMAT_FLAG_ALPHA) == 0 &&
+               (f & PNG_FORMAT_FLAG_AFIRST) != 0)
+#        else
+            if ((f & 0x20U/*HACK: fixed value*/) != 0)
+#        endif
             continue;
 
          format_set(pf, f);
@@ -786,6 +795,7 @@ gp_ga8(Pixel *p, png_const_voidp pb)
    p->a = pp[1];
 }
 
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
 static void
 gp_ag8(Pixel *p, png_const_voidp pb)
 {
@@ -794,6 +804,7 @@ gp_ag8(Pixel *p, png_const_voidp pb)
    p->r = p->g = p->b = pp[1];
    p->a = pp[0];
 }
+#endif
 
 static void
 gp_rgb8(Pixel *p, png_const_voidp pb)
@@ -806,6 +817,7 @@ gp_rgb8(Pixel *p, png_const_voidp pb)
    p->a = 255;
 }
 
+#ifdef PNG_FORMAT_BGR_SUPPORTED
 static void
 gp_bgr8(Pixel *p, png_const_voidp pb)
 {
@@ -816,6 +828,7 @@ gp_bgr8(Pixel *p, png_const_voidp pb)
    p->b = pp[0];
    p->a = 255;
 }
+#endif
 
 static void
 gp_rgba8(Pixel *p, png_const_voidp pb)
@@ -828,6 +841,7 @@ gp_rgba8(Pixel *p, png_const_voidp pb)
    p->a = pp[3];
 }
 
+#ifdef PNG_FORMAT_BGR_SUPPORTED
 static void
 gp_bgra8(Pixel *p, png_const_voidp pb)
 {
@@ -838,7 +852,9 @@ gp_bgra8(Pixel *p, png_const_voidp pb)
    p->b = pp[0];
    p->a = pp[3];
 }
+#endif
 
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
 static void
 gp_argb8(Pixel *p, png_const_voidp pb)
 {
@@ -849,7 +865,9 @@ gp_argb8(Pixel *p, png_const_voidp pb)
    p->b = pp[3];
    p->a = pp[0];
 }
+#endif
 
+#if defined(PNG_FORMAT_AFIRST_SUPPORTED) && defined(PNG_FORMAT_BGR_SUPPORTED)
 static void
 gp_abgr8(Pixel *p, png_const_voidp pb)
 {
@@ -860,6 +878,7 @@ gp_abgr8(Pixel *p, png_const_voidp pb)
    p->b = pp[1];
    p->a = pp[0];
 }
+#endif
 
 static void
 gp_g16(Pixel *p, png_const_voidp pb)
@@ -879,6 +898,7 @@ gp_ga16(Pixel *p, png_const_voidp pb)
    p->a = pp[1];
 }
 
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
 static void
 gp_ag16(Pixel *p, png_const_voidp pb)
 {
@@ -887,6 +907,7 @@ gp_ag16(Pixel *p, png_const_voidp pb)
    p->r = p->g = p->b = pp[1];
    p->a = pp[0];
 }
+#endif
 
 static void
 gp_rgb16(Pixel *p, png_const_voidp pb)
@@ -899,6 +920,7 @@ gp_rgb16(Pixel *p, png_const_voidp pb)
    p->a = 65535;
 }
 
+#ifdef PNG_FORMAT_BGR_SUPPORTED
 static void
 gp_bgr16(Pixel *p, png_const_voidp pb)
 {
@@ -909,6 +931,7 @@ gp_bgr16(Pixel *p, png_const_voidp pb)
    p->b = pp[0];
    p->a = 65535;
 }
+#endif
 
 static void
 gp_rgba16(Pixel *p, png_const_voidp pb)
@@ -921,6 +944,7 @@ gp_rgba16(Pixel *p, png_const_voidp pb)
    p->a = pp[3];
 }
 
+#ifdef PNG_FORMAT_BGR_SUPPORTED
 static void
 gp_bgra16(Pixel *p, png_const_voidp pb)
 {
@@ -931,7 +955,9 @@ gp_bgra16(Pixel *p, png_const_voidp pb)
    p->b = pp[0];
    p->a = pp[3];
 }
+#endif
 
+#ifdef PNG_FORMAT_AFIRST_SUPPORTED
 static void
 gp_argb16(Pixel *p, png_const_voidp pb)
 {
@@ -942,7 +968,9 @@ gp_argb16(Pixel *p, png_const_voidp pb)
    p->b = pp[3];
    p->a = pp[0];
 }
+#endif
 
+#if defined(PNG_FORMAT_AFIRST_SUPPORTED) && defined(PNG_FORMAT_BGR_SUPPORTED)
 static void
 gp_abgr16(Pixel *p, png_const_voidp pb)
 {
@@ -953,6 +981,7 @@ gp_abgr16(Pixel *p, png_const_voidp pb)
    p->b = pp[1];
    p->a = pp[0];
 }
+#endif
 
 /* Given a format, return the correct one of the above functions. */
 static void (*
@@ -966,29 +995,35 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
    {
       if (format & PNG_FORMAT_FLAG_COLOR)
       {
-         if (format & PNG_FORMAT_FLAG_BGR)
-         {
-            if (format & PNG_FORMAT_FLAG_ALPHA)
+#        ifdef PNG_FORMAT_BGR_SUPPORTED
+            if (format & PNG_FORMAT_FLAG_BGR)
             {
-               if (format & PNG_FORMAT_FLAG_AFIRST)
-                  return gp_abgr16;
+               if (format & PNG_FORMAT_FLAG_ALPHA)
+               {
+#                 ifdef PNG_FORMAT_AFIRST_SUPPORTED
+                     if (format & PNG_FORMAT_FLAG_AFIRST)
+                        return gp_abgr16;
+
+                     else
+#                 endif
+                     return gp_bgra16;
+               }
 
                else
-                  return gp_bgra16;
+                  return gp_bgr16;
             }
 
             else
-               return gp_bgr16;
-         }
-
-         else
+#        endif
          {
             if (format & PNG_FORMAT_FLAG_ALPHA)
             {
-               if (format & PNG_FORMAT_FLAG_AFIRST)
-                  return gp_argb16;
+#              ifdef PNG_FORMAT_AFIRST_SUPPORTED
+                  if (format & PNG_FORMAT_FLAG_AFIRST)
+                     return gp_argb16;
 
-               else
+                  else
+#              endif
                   return gp_rgba16;
             }
 
@@ -1001,10 +1036,12 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
       {
          if (format & PNG_FORMAT_FLAG_ALPHA)
          {
-            if (format & PNG_FORMAT_FLAG_AFIRST)
-               return gp_ag16;
+#           ifdef PNG_FORMAT_AFIRST_SUPPORTED
+               if (format & PNG_FORMAT_FLAG_AFIRST)
+                  return gp_ag16;
 
-            else
+               else
+#           endif
                return gp_ga16;
          }
 
@@ -1017,29 +1054,35 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
    {
       if (format & PNG_FORMAT_FLAG_COLOR)
       {
-         if (format & PNG_FORMAT_FLAG_BGR)
-         {
-            if (format & PNG_FORMAT_FLAG_ALPHA)
+#        ifdef PNG_FORMAT_BGR_SUPPORTED
+            if (format & PNG_FORMAT_FLAG_BGR)
             {
-               if (format & PNG_FORMAT_FLAG_AFIRST)
-                  return gp_abgr8;
+               if (format & PNG_FORMAT_FLAG_ALPHA)
+               {
+#                 ifdef PNG_FORMAT_AFIRST_SUPPORTED
+                     if (format & PNG_FORMAT_FLAG_AFIRST)
+                        return gp_abgr8;
+
+                     else
+#                 endif
+                     return gp_bgra8;
+               }
 
                else
-                  return gp_bgra8;
+                  return gp_bgr8;
             }
 
             else
-               return gp_bgr8;
-         }
-
-         else
+#        endif
          {
             if (format & PNG_FORMAT_FLAG_ALPHA)
             {
-               if (format & PNG_FORMAT_FLAG_AFIRST)
-                  return gp_argb8;
+#              ifdef PNG_FORMAT_AFIRST_SUPPORTED
+                  if (format & PNG_FORMAT_FLAG_AFIRST)
+                     return gp_argb8;
 
-               else
+                  else
+#              endif
                   return gp_rgba8;
             }
 
@@ -1052,10 +1095,12 @@ get_pixel(png_uint_32 format))(Pixel *p, png_const_voidp pb)
       {
          if (format & PNG_FORMAT_FLAG_ALPHA)
          {
-            if (format & PNG_FORMAT_FLAG_AFIRST)
-               return gp_ag8;
+#           ifdef PNG_FORMAT_AFIRST_SUPPORTED
+               if (format & PNG_FORMAT_FLAG_AFIRST)
+                  return gp_ag8;
 
-            else
+               else
+#           endif
                return gp_ga8;
          }
 
@@ -2618,13 +2663,15 @@ component_loc(png_byte loc[4], png_uint_32 format)
 
       loc[2] = 1;
 
-      if (format & PNG_FORMAT_FLAG_BGR)
-      {
-         loc[1] = 2;
-         loc[3] = 0;
-      }
+#     ifdef PNG_FORMAT_BGR_SUPPORTED
+         if (format & PNG_FORMAT_FLAG_BGR)
+         {
+            loc[1] = 2;
+            loc[3] = 0;
+         }
 
-      else
+         else
+#     endif
       {
          loc[1] = 0;
          loc[3] = 2;
@@ -2639,15 +2686,17 @@ component_loc(png_byte loc[4], png_uint_32 format)
 
    if (format & PNG_FORMAT_FLAG_ALPHA)
    {
-      if (format & PNG_FORMAT_FLAG_AFIRST)
-      {
-         loc[0] = 0;
-         ++loc[1];
-         ++loc[2];
-         ++loc[3];
-      }
+#     ifdef PNG_FORMAT_AFIRST_SUPPORTED
+         if (format & PNG_FORMAT_FLAG_AFIRST)
+         {
+            loc[0] = 0;
+            ++loc[1];
+            ++loc[2];
+            ++loc[3];
+         }
 
-      else
+         else
+#     endif
          loc[0] = channels;
 
       ++channels;
@@ -3017,17 +3066,25 @@ read_file(Image *image, png_uint_32 format, png_const_colorp background)
          return logerror(image, "memory init: ", image->file_name, "");
    }
 
-   else if (image->input_file != NULL)
-   {
-      if (!png_image_begin_read_from_stdio(&image->image, image->input_file))
-         return logerror(image, "stdio init: ", image->file_name, "");
-   }
+#  ifdef PNG_STDIO_SUPPORTED
+      else if (image->input_file != NULL)
+      {
+         if (!png_image_begin_read_from_stdio(&image->image, image->input_file))
+            return logerror(image, "stdio init: ", image->file_name, "");
+      }
 
-   else
-   {
-      if (!png_image_begin_read_from_file(&image->image, image->file_name))
-         return logerror(image, "file init: ", image->file_name, "");
-   }
+      else
+      {
+         if (!png_image_begin_read_from_file(&image->image, image->file_name))
+            return logerror(image, "file init: ", image->file_name, "");
+      }
+#  else
+      else
+      {
+         return logerror(image, "unsupported file/stdio init: ",
+            image->file_name, "");
+      }
+#  endif
 
    /* This must be set after the begin_read call: */
    if (image->opts & sRGB_16BIT)
@@ -3466,11 +3523,19 @@ main(int argc, char **argv)
          memset(gpc_error_via_linear, 0, sizeof gpc_error_via_linear);
       }
       else if (strcmp(arg, "--file") == 0)
-         opts |= READ_FILE;
+#        ifdef PNG_STDIO_SUPPORTED
+            opts |= READ_FILE;
+#        else
+            return 77; /* skipped: no support */
+#        endif
       else if (strcmp(arg, "--memory") == 0)
          opts &= ~READ_FILE;
       else if (strcmp(arg, "--stdio") == 0)
-         opts |= USE_STDIO;
+#        ifdef PNG_STDIO_SUPPORTED
+            opts |= USE_STDIO;
+#        else
+            return 77; /* skipped: no support */
+#        endif
       else if (strcmp(arg, "--name") == 0)
          opts &= ~USE_STDIO;
       else if (strcmp(arg, "--verbose") == 0)

contrib/libtests/pngunknown.c

@@ -30,7 +30,19 @@
 #  include "../../png.h"
 #endif
 
-#ifdef PNG_READ_SUPPORTED
+/* Since this program tests the ability to change the unknown chunk handling
+ * these must be defined:
+ */
+#if defined(PNG_SET_UNKNOWN_CHUNKS_SUPPORTED) &&\
+   defined(PNG_READ_SUPPORTED)
+
+/* One of these must be defined to allow us to find out what happened.  It is
+ * still useful to set unknown chunk handling without either of these in order
+ * to cause *known* chunks to be discarded.  This can be a significant
+ * efficiency gain, but it can't really be tested here.
+ */
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) ||\
+   defined(PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED)
 
 #if PNG_LIBPNG_VER < 10500
 /* This deliberately lacks the PNG_CONST. */
@@ -75,43 +87,74 @@ typedef png_byte *png_const_bytep;
 #  define png_const_structp png_structp
 #endif
 
+#if PNG_LIBPNG_VER < 10700
+   /* Copied from libpng 1.7.0 png.h */
+#define PNG_u2(b1, b2) (((unsigned int)(b1) << 8) + (b2))
 
-/* Copied from pngpriv.h */
-#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
-#define PNG_CHUNK(b1,b2,b3,b4) \
-   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
+#define PNG_U16(b1, b2) ((png_uint_16)PNG_u2(b1, b2))
+#define PNG_U32(b1, b2, b3, b4)\
+   (((png_uint_32)PNG_u2(b1, b2) << 16) + PNG_u2(b3, b4))
 
-#define png_IHDR PNG_CHUNK( 73,  72,  68,  82)
-#define png_IDAT PNG_CHUNK( 73,  68,  65,  84)
-#define png_IEND PNG_CHUNK( 73,  69,  78,  68)
-#define png_PLTE PNG_CHUNK( 80,  76,  84,  69)
-#define png_bKGD PNG_CHUNK( 98,  75,  71,  68)
-#define png_cHRM PNG_CHUNK( 99,  72,  82,  77)
-#define png_gAMA PNG_CHUNK(103,  65,  77,  65)
-#define png_hIST PNG_CHUNK(104,  73,  83,  84)
-#define png_iCCP PNG_CHUNK(105,  67,  67,  80)
-#define png_iTXt PNG_CHUNK(105,  84,  88, 116)
-#define png_oFFs PNG_CHUNK(111,  70,  70, 115)
-#define png_pCAL PNG_CHUNK(112,  67,  65,  76)
-#define png_sCAL PNG_CHUNK(115,  67,  65,  76)
-#define png_pHYs PNG_CHUNK(112,  72,  89, 115)
-#define png_sBIT PNG_CHUNK(115,  66,  73,  84)
-#define png_sPLT PNG_CHUNK(115,  80,  76,  84)
-#define png_sRGB PNG_CHUNK(115,  82,  71,  66)
-#define png_sTER PNG_CHUNK(115,  84,  69,  82)
-#define png_tEXt PNG_CHUNK(116,  69,  88, 116)
-#define png_tIME PNG_CHUNK(116,  73,  77,  69)
-#define png_tRNS PNG_CHUNK(116,  82,  78,  83)
-#define png_zTXt PNG_CHUNK(122,  84,  88, 116)
-#define png_vpAg PNG_CHUNK('v', 'p', 'A', 'g')
+/* Constants for known chunk types.
+ */
+#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_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)
+#define png_tEXt PNG_U32(116,  69,  88, 116)
+#define png_tIME PNG_U32(116,  73,  77,  69)
+#define png_tRNS PNG_U32(116,  82,  78,  83)
+#define png_zTXt PNG_U32(122,  84,  88, 116)
 
 /* Test on flag values as defined in the spec (section 5.4): */
-#define PNG_CHUNK_ANCILLARY(c )   (1 & ((c) >> 29))
+#define PNG_CHUNK_ANCILLARY(c)    (1 & ((c) >> 29))
 #define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLARY(c))
 #define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
 #define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
 #define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
 
+#endif /* PNG_LIBPNG_VER < 10700 */
+
+#ifdef __cplusplus
+#  define this not_the_cpp_this
+#  define new not_the_cpp_new
+#  define voidcast(type, value) static_cast<type>(value)
+#else
+#  define voidcast(type, value) (value)
+#endif /* __cplusplus */
+
+/* Unused formal parameter errors are removed using the following macro which is
+ * expected to have no bad effects on performance.
+ */
+#ifndef UNUSED
+#  if defined(__GNUC__) || defined(_MSC_VER)
+#     define UNUSED(param) (void)param;
+#  else
+#     define UNUSED(param)
+#  endif
+#endif
+
+/* Types of chunks not known to libpng */
+#define png_vpAg PNG_U32(118, 112, 65, 103)
+
 /* Chunk information */
 #define PNG_INFO_tEXt 0x10000000U
 #define PNG_INFO_iTXt 0x20000000U
@@ -139,8 +182,8 @@ static struct
    { "PLTE", PNG_INFO_PLTE, png_PLTE, 0, 0, ABSENT, 0 },
 
    /* Non-critical chunks that libpng handles */
-   /* This is a mess but it seems to be the only way to do it - there is no way to
-    * check for definition outside a #if.
+   /* This is a mess but it seems to be the only way to do it - there is no way
+    * to check for a definition outside a #if.
     */
    { "bKGD", PNG_INFO_bKGD, png_bKGD,
 #     ifdef PNG_READ_bKGD_SUPPORTED
@@ -317,14 +360,16 @@ find_by_flag(png_uint_32 flag)
 static int
 ancillary(const char *name)
 {
-   return PNG_CHUNK_ANCILLARY(PNG_CHUNK(name[0], name[1], name[2], name[3]));
+   return PNG_CHUNK_ANCILLARY(PNG_U32(name[0], name[1], name[2], name[3]));
 }
 
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 static int
 ancillaryb(const png_byte *name)
 {
-   return PNG_CHUNK_ANCILLARY(PNG_CHUNK(name[0], name[1], name[2], name[3]));
+   return PNG_CHUNK_ANCILLARY(PNG_U32(name[0], name[1], name[2], name[3]));
 }
+#endif
 
 /* Type of an error_ptr */
 typedef struct
@@ -332,8 +377,11 @@ typedef struct
    jmp_buf     error_return;
    png_structp png_ptr;
    png_infop   info_ptr, end_ptr;
+   png_uint_32 before_IDAT;
+   png_uint_32 after_IDAT;
    int         error_count;
    int         warning_count;
+   int         keep; /* the default value */
    const char *program;
    const char *file;
    const char *test;
@@ -366,9 +414,6 @@ clean_display(display *d)
          d->test);
       exit(1);
    }
-
-   /* Invalidate the test */
-   d->test = init;
 }
 
 PNG_FUNCTION(void, display_exit, (display *d), static PNG_NORETURN)
@@ -444,11 +489,88 @@ get_valid(display *d, png_infop info_ptr)
    return flags;
 }
 
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+static int
+read_callback(png_structp pp, png_unknown_chunkp pc)
+{
+   /* This function mimics the behavior of png_set_keep_unknown_chunks by
+    * returning '0' to keep the chunk and '1' to discard it.
+    */
+   display *d = voidcast(display*, png_get_user_chunk_ptr(pp));
+   int chunk = findb(pc->name);
+   int keep, discard;
+
+   if (chunk < 0) /* not one in our list, so not a known chunk */
+      keep = d->keep;
+
+   else
+   {
+      keep = chunk_info[chunk].keep;
+      if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
+      {
+         /* See the comments in png.h - use the default for unknown chunks,
+          * do not keep known chunks.
+          */
+         if (chunk_info[chunk].unknown)
+            keep = d->keep;
+
+         else
+            keep = PNG_HANDLE_CHUNK_NEVER;
+      }
+   }
+
+   switch (keep)
+   {
+      default:
+         fprintf(stderr, "%s(%s): %d: unrecognized chunk option\n", d->file,
+            d->test, chunk_info[chunk].keep);
+         display_exit(d);
+
+      case PNG_HANDLE_CHUNK_AS_DEFAULT:
+      case PNG_HANDLE_CHUNK_NEVER:
+         discard = 1/*handled; discard*/;
+         break;
+
+      case PNG_HANDLE_CHUNK_IF_SAFE:
+      case PNG_HANDLE_CHUNK_ALWAYS:
+         discard = 0/*not handled; keep*/;
+         break;
+   }
+
+   /* Also store information about this chunk in the display, the relevant flag
+    * is set if the chunk is to be kept ('not handled'.)
+    */
+   if (chunk >= 0) if (!discard) /* stupidity to stop a GCC warning */
+   {
+      png_uint_32 flag = chunk_info[chunk].flag;
+
+      if (pc->location & PNG_AFTER_IDAT)
+         d->after_IDAT |= flag;
+
+      else
+         d->before_IDAT |= flag;
+   }
+
+   /* However if there is no support to store unknown chunks don't ask libpng to
+    * do it; there will be an png_error.
+    */
+#  ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+      return discard;
+#  else
+      return 1; /*handled; discard*/
+#  endif
+}
+#endif /* READ_USER_CHUNKS_SUPPORTED */
+
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 static png_uint_32
-get_unknown(display *d, int def, png_infop info_ptr)
+get_unknown(display *d, png_infop info_ptr, int after_IDAT)
 {
    /* Create corresponding 'unknown' flags */
    png_uint_32 flags = 0;
+
+   UNUSED(after_IDAT)
+
    {
       png_unknown_chunkp unknown;
       int num_unknown = png_get_unknown_chunks(d->png_ptr, info_ptr, &unknown);
@@ -458,16 +580,16 @@ get_unknown(display *d, int def, png_infop info_ptr)
          int chunk = findb(unknown[num_unknown].name);
 
          /* Chunks not known to pngunknown must be validated here; since they
-          * must also be unknown to libpng the 'def' behavior should have been
-          * used.
+          * must also be unknown to libpng the 'display->keep' behavior should
+          * have been used.
           */
-         if (chunk < 0) switch (def)
+         if (chunk < 0) switch (d->keep)
          {
             default: /* impossible */
             case PNG_HANDLE_CHUNK_AS_DEFAULT:
             case PNG_HANDLE_CHUNK_NEVER:
                fprintf(stderr, "%s(%s): %s: %s: unknown chunk saved\n",
-                  d->file, d->test, def ? "discard" : "default",
+                  d->file, d->test, d->keep ? "discard" : "default",
                   unknown[num_unknown].name);
                ++(d->error_count);
                break;
@@ -493,14 +615,39 @@ get_unknown(display *d, int def, png_infop info_ptr)
 
    return flags;
 }
+#else
+static png_uint_32
+get_unknown(display *d, png_infop info_ptr, int after_IDAT)
+   /* Otherwise this will return the cached values set by any user callback */
+{
+   UNUSED(info_ptr);
+
+   if (after_IDAT)
+      return d->after_IDAT;
+
+   else
+      return d->before_IDAT;
+}
+
+#  ifndef PNG_READ_USER_CHUNKS_SUPPORTED
+      /* The #defines above should mean this is never reached, it's just here as
+       * a check to ensure the logic is correct.
+       */
+#     error No store support and no user chunk support, this will not work
+#  endif
+#endif
 
 static int
 check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
-   display *d)
+   display *d, int set_callback)
 {
-   int i, def = PNG_HANDLE_CHUNK_AS_DEFAULT, npasses, ipass;
+   int i, npasses, ipass;
    png_uint_32 height;
 
+   d->keep = PNG_HANDLE_CHUNK_AS_DEFAULT;
+   d->before_IDAT = 0;
+   d->after_IDAT = 0;
+
    /* Some of these errors are permanently fatal and cause an exit here, others
     * are per-test and cause an error return.
     */
@@ -526,6 +673,16 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
 
    png_init_io(d->png_ptr, fp);
 
+#  ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+      /* This is only done if requested by the caller; it interferes with the
+       * standard store/save mechanism.
+       */
+      if (set_callback)
+         png_set_read_user_chunk_fn(d->png_ptr, d, read_callback);
+#  else
+      UNUSED(set_callback)
+#  endif
+
    /* Handle each argument in turn; multiple settings are possible for the same
     * chunk and multiple calls will occur (the last one should override all
     * preceding ones).
@@ -565,13 +722,11 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
                    * in this case, so we just check the arguments!  This could
                    * be improved in the future by using the read callback.
                    */
-#                 ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
-                     png_byte name[5];
+                  png_byte name[5];
 
-                     memcpy(name, chunk_info[chunk].name, 5);
-                     png_set_keep_unknown_chunks(d->png_ptr, option, name, 1);
-                     chunk_info[chunk].keep = option;
-#                 endif
+                  memcpy(name, chunk_info[chunk].name, 5);
+                  png_set_keep_unknown_chunks(d->png_ptr, option, name, 1);
+                  chunk_info[chunk].keep = option;
                   continue;
                }
 
@@ -580,10 +735,8 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
             case 7: /* default */
                if (memcmp(argv[i], "default", 7) == 0)
                {
-#                 ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
-                     png_set_keep_unknown_chunks(d->png_ptr, option, NULL, 0);
-#                 endif
-                  def = option;
+                  png_set_keep_unknown_chunks(d->png_ptr, option, NULL, 0);
+                  d->keep = option;
                   continue;
                }
 
@@ -592,14 +745,12 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
             case 3: /* all */
                if (memcmp(argv[i], "all", 3) == 0)
                {
-#                 ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
-                     png_set_keep_unknown_chunks(d->png_ptr, option, NULL, -1);
-                     def = option;
+                  png_set_keep_unknown_chunks(d->png_ptr, option, NULL, -1);
+                  d->keep = option;
 
-                     for (chunk = 0; chunk < NINFO; ++chunk)
-                        if (chunk_info[chunk].all)
-                           chunk_info[chunk].keep = option;
-#                 endif
+                  for (chunk = 0; chunk < NINFO; ++chunk)
+                     if (chunk_info[chunk].all)
+                        chunk_info[chunk].keep = option;
                   continue;
                }
 
@@ -673,18 +824,18 @@ check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/,
    png_read_end(d->png_ptr, d->end_ptr);
 
    flags[0] = get_valid(d, d->info_ptr);
-   flags[1] = get_unknown(d, def, d->info_ptr);
+   flags[1] = get_unknown(d, d->info_ptr, 0/*before IDAT*/);
 
    /* Only png_read_png sets PNG_INFO_IDAT! */
    flags[chunk_info[0/*IDAT*/].keep != PNG_HANDLE_CHUNK_AS_DEFAULT] |=
       PNG_INFO_IDAT;
 
    flags[2] = get_valid(d, d->end_ptr);
-   flags[3] = get_unknown(d, def, d->end_ptr);
+   flags[3] = get_unknown(d, d->end_ptr, 1/*after IDAT*/);
 
    clean_display(d);
 
-   return def;
+   return d->keep;
 }
 
 static void
@@ -705,7 +856,7 @@ check_error(display *d, png_uint_32 flags, const char *message)
 
 static void
 check_handling(display *d, int def, png_uint_32 chunks, png_uint_32 known,
-   png_uint_32 unknown, const char *position)
+   png_uint_32 unknown, const char *position, int set_callback)
 {
    while (chunks)
    {
@@ -812,8 +963,9 @@ check_handling(display *d, int def, png_uint_32 chunks, png_uint_32 known,
       if (errorx != NULL)
       {
          ++(d->error_count);
-         fprintf(stderr, "%s(%s): %s %s %s: %s\n",
-            d->file, d->test, type, chunk_info[i].name, position, errorx);
+         fprintf(stderr, "%s(%s%s): %s %s %s: %s\n", d->file, d->test,
+            set_callback ? ",callback" : "",
+            type, chunk_info[i].name, position, errorx);
       }
 
       chunks &= ~flag;
@@ -822,7 +974,7 @@ check_handling(display *d, int def, png_uint_32 chunks, png_uint_32 known,
 
 static void
 perform_one_test(FILE *fp, int argc, const char **argv,
-   png_uint_32 *default_flags, display *d)
+   png_uint_32 *default_flags, display *d, int set_callback)
 {
    int def;
    png_uint_32 flags[2][4];
@@ -831,7 +983,7 @@ perform_one_test(FILE *fp, int argc, const char **argv,
    clear_keep();
    memcpy(flags[0], default_flags, sizeof flags[0]);
 
-   def = check(fp, argc, argv, flags[1], d);
+   def = check(fp, argc, argv, flags[1], d, set_callback);
 
    /* Chunks should either be known or unknown, never both and this should apply
     * whether the chunk is before or after the IDAT (actually, the app can
@@ -866,9 +1018,9 @@ perform_one_test(FILE *fp, int argc, const char **argv,
     * it or not.
     */
    check_handling(d, def, flags[0][0] | flags[0][1], flags[1][0], flags[1][1],
-      "before IDAT");
+      "before IDAT", set_callback);
    check_handling(d, def, flags[0][2] | flags[0][3], flags[1][2], flags[1][3],
-      "after IDAT");
+      "after IDAT", set_callback);
 }
 
 static void
@@ -878,7 +1030,12 @@ perform_one_test_safe(FILE *fp, int argc, const char **argv,
    if (setjmp(d->error_return) == 0)
    {
       d->test = test; /* allow use of d->error_return */
-      perform_one_test(fp, argc, argv, default_flags, d);
+#     ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+         perform_one_test(fp, argc, argv, default_flags, d, 0);
+#     endif
+#     ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+         perform_one_test(fp, argc, argv, default_flags, d, 1);
+#     endif
       d->test = init; /* prevent use of d->error_return */
    }
 }
@@ -902,7 +1059,7 @@ usage(const char *program, const char *reason)
    fprintf(stderr, "pngunknown: %s: usage:\n %s [--strict] "
       "--default|{(CHNK|default|all)=(default|discard|if-safe|save)} "
       "testfile.png\n", reason, program);
-   exit(2);
+   exit(99);
 }
 
 int
@@ -950,11 +1107,6 @@ main(int argc, const char **argv)
    else if (default_tests) if (argc != 1)
       usage(d.program, "extra arguments");
 
-#  ifndef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
-      fprintf(stderr, "%s: warning: no 'save' support so arguments ignored\n",
-         d.program);
-#  endif
-
    /* The name of the test file is the last argument; remove it. */
    d.file = argv[--argc];
 
@@ -962,24 +1114,40 @@ main(int argc, const char **argv)
    if (fp == NULL)
    {
       perror(d.file);
-      exit(2);
+      exit(99);
    }
 
    /* First find all the chunks, known and unknown, in the test file, a failure
     * here aborts the whole test.
+    *
+    * If 'save' is supported then the normal saving method should happen,
+    * otherwise if 'read' is supported then the read callback will do the
+    * same thing.  If both are supported the 'read' callback won't be
+    * instantiated by default.  If 'save' is *not* supported then a user
+    * callback is required even though we can call png_get_unknown_chunks.
     */
-   if (check(fp, 1, &count_argv, default_flags, &d) !=
-      PNG_HANDLE_CHUNK_ALWAYS)
+   if (check(fp, 1, &count_argv, default_flags, &d,
+#     ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+         0
+#     else
+         1
+#     endif
+      ) != PNG_HANDLE_CHUNK_ALWAYS)
    {
       fprintf(stderr, "%s: %s: internal error\n", d.program, d.file);
-      exit(3);
+      exit(99);
    }
 
    /* Now find what the various supplied options cause to change: */
    if (!default_tests)
    {
       d.test = cmd; /* acts as a flag to say exit, do not longjmp */
-      perform_one_test(fp, argc, argv, default_flags, &d);
+#     ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
+         perform_one_test(fp, argc, argv, default_flags, &d, 0);
+#     endif
+#     ifdef PNG_READ_USER_CHUNKS_SUPPORTED
+         perform_one_test(fp, argc, argv, default_flags, &d, 1);
+#     endif
       d.test = init;
    }
 
@@ -1037,14 +1205,14 @@ main(int argc, const char **argv)
             if (fclose(fsuccess) || err)
             {
                fprintf(stderr, "%s: write failed\n", touch_file);
-               exit(1);
+               exit(99);
             }
          }
 
          else
          {
             fprintf(stderr, "%s: open failed\n", touch_file);
-            exit(1);
+            exit(99);
          }
       }
 
@@ -1054,13 +1222,24 @@ main(int argc, const char **argv)
    return 1;
 }
 
-#else
+#else /* !(READ_USER_CHUNKS || SAVE_UNKNOWN_CHUNKS) */
 int
 main(void)
 {
    fprintf(stderr,
-   " test ignored because libpng was not built with unknown chunk support\n");
+      " test ignored: no support to find out about unknown chunks\n");
    /* So the test is skipped: */
    return 77;
 }
-#endif
+#endif /* READ_USER_CHUNKS || SAVE_UNKNOWN_CHUNKS */
+
+#else /* !(SET_UNKNOWN_CHUNKS && READ) */
+int
+main(void)
+{
+   fprintf(stderr,
+      " test ignored: no support to modify unknown chunk handling\n");
+   /* So the test is skipped: */
+   return 77;
+}
+#endif /* SET_UNKNOWN_CHUNKS && READ*/

contrib/libtests/pngvalid.c

@@ -1,7 +1,7 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
@@ -43,7 +43,10 @@
 #  include "../../png.h"
 #endif
 
-#ifdef PNG_WRITE_SUPPORTED /* else pngvalid can do nothing */
+/* pngvalid requires write support and one of the fixed or floating point APIs.
+ */
+#if defined(PNG_WRITE_SUPPORTED) &&\
+   (defined(PNG_FIXED_POINT_SUPPORTED) || defined(PNG_FLOATING_POINT_SUPPORTED))
 
 #if PNG_LIBPNG_VER < 10500
 /* This deliberately lacks the PNG_CONST. */
@@ -106,6 +109,11 @@ typedef png_byte *png_const_bytep;
 #  endif
 #endif
 
+/* Fixups for various minimal builds */
+#ifndef PNG_ERROR_TEXT_SUPPORTED
+#  define png_error(a,b) png_err(a)
+#endif
+
 /***************************** EXCEPTION HANDLING *****************************/
 #ifdef PNG_FREESTANDING_TESTS
 #  include <cexcept.h>
@@ -616,7 +624,12 @@ typedef struct png_store
    unsigned int       validated :1;   /* used as a temporary flag */
    int                nerrors;
    int                nwarnings;
-   char               test[128]; /* Name of test */
+   int                noptions;       /* number of options below: */
+   struct {
+      unsigned char   option;         /* option number, 0..30 */
+      unsigned char   setting;        /* setting (unset,invalid,on,off) */
+   }                  options[16];
+   char               test[128];      /* Name of test */
    char               error[256];
 
    /* Read fields */
@@ -717,6 +730,7 @@ store_init(png_store* ps)
    ps->new.prev = NULL;
    ps->palette = NULL;
    ps->npalette = 0;
+   ps->noptions = 0;
 }
 
 static void
@@ -1257,6 +1271,7 @@ store_current_palette(png_store *ps, int *npalette)
 #endif /* PNG_READ_SUPPORTED */
 
 /***************************** MEMORY MANAGEMENT*** ***************************/
+#ifdef PNG_USER_MEM_SUPPORTED
 /* A store_memory is simply the header for an allocated block of memory.  The
  * pointer returned to libpng is just after the end of the header block, the
  * allocated memory is followed by a second copy of the 'mark'.
@@ -1457,6 +1472,7 @@ store_free(png_structp ppIn, png_voidp memory)
    this->next = NULL;
    store_memory_free(pp, pool, this);
 }
+#endif /* PNG_USER_MEM_SUPPORTED */
 
 /* Setup functions. */
 /* Cleanup when aborting a write or after storing the new file. */
@@ -1482,7 +1498,9 @@ store_write_reset(png_store *ps)
    /* And make sure that all the memory has been freed - this will output
     * spurious errors in the case of memory corruption above, but this is safe.
     */
-   store_pool_delete(ps, &ps->write_memory_pool);
+#  ifdef PNG_USER_MEM_SUPPORTED
+      store_pool_delete(ps, &ps->write_memory_pool);
+#  endif
 
    store_freenew(ps);
 }
@@ -1506,18 +1524,32 @@ set_store_for_write(png_store *ps, png_infopp ppi,
       store_write_reset(ps);
       safecat(ps->wname, sizeof ps->wname, 0, name);
 
-      /* Don't do the slow memory checks if doing a speed test. */
-      if (ps->speed)
+      /* Don't do the slow memory checks if doing a speed test, also if user
+       * memory is not supported we can't do it anyway.
+       */
+#     ifdef PNG_USER_MEM_SUPPORTED
+         if (!ps->speed)
+            ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
+               ps, store_error, store_warning, &ps->write_memory_pool,
+               store_malloc, store_free);
+
+         else
+#     endif
          ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING,
             ps, store_error, store_warning);
 
-      else
-         ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING,
-            ps, store_error, store_warning, &ps->write_memory_pool,
-            store_malloc, store_free);
-
       png_set_write_fn(ps->pwrite, ps, store_write, store_flush);
 
+#     ifdef PNG_SET_OPTION_SUPPORTED
+         {
+            int opt;
+            for (opt=0; opt<ps->noptions; ++opt)
+               if (png_set_option(ps->pwrite, ps->options[opt].option,
+                  ps->options[opt].setting) == PNG_OPTION_INVALID)
+                  png_error(ps->pwrite, "png option invalid");
+         }
+#     endif
+
       if (ppi != NULL)
          *ppi = ps->piwrite = png_create_info_struct(ps->pwrite);
    }
@@ -1553,8 +1585,10 @@ store_read_reset(png_store *ps)
       }
 #  endif
 
-   /* Always do this to be safe. */
-   store_pool_delete(ps, &ps->read_memory_pool);
+#  ifdef PNG_USER_MEM_SUPPORTED
+      /* Always do this to be safe. */
+      store_pool_delete(ps, &ps->read_memory_pool);
+#  endif
 
    ps->current = NULL;
    ps->next = NULL;
@@ -1581,14 +1615,14 @@ store_read_set(png_store *ps, png_uint_32 id)
       pf = pf->next;
    }
 
-      {
+   {
       size_t pos;
       char msg[FILE_NAME_SIZE+64];
 
       pos = standard_name_from_id(msg, sizeof msg, 0, id);
       pos = safecat(msg, sizeof msg, pos, ": file not found");
       png_error(ps->pread, msg);
-      }
+   }
 }
 
 /* The main interface for reading a saved file - pass the id number of the file
@@ -1614,14 +1648,16 @@ set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id,
     * However, given that store_error works correctly in these circumstances
     * we don't ever expect NULL in this program.
     */
-   if (ps->speed)
-      ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps,
-          store_error, store_warning);
+#  ifdef PNG_USER_MEM_SUPPORTED
+      if (!ps->speed)
+         ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps,
+             store_error, store_warning, &ps->read_memory_pool, store_malloc,
+             store_free);
 
-   else
-      ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps,
-          store_error, store_warning, &ps->read_memory_pool, store_malloc,
-          store_free);
+      else
+#  endif
+   ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, store_error,
+      store_warning);
 
    if (ps->pread == NULL)
    {
@@ -1633,6 +1669,16 @@ set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id,
       Throw ps;
    }
 
+#  ifdef PNG_SET_OPTION_SUPPORTED
+      {
+         int opt;
+         for (opt=0; opt<ps->noptions; ++opt)
+            if (png_set_option(ps->pread, ps->options[opt].option,
+               ps->options[opt].setting) == PNG_OPTION_INVALID)
+                  png_error(ps->pread, "png option invalid");
+      }
+#  endif
+
    store_read_set(ps, id);
 
    if (ppi != NULL)
@@ -1908,7 +1954,7 @@ typedef struct png_modifier
 
 /* This returns true if the test should be stopped now because it has already
  * failed and it is running silently.
- */
+  */
 static int fail(png_modifier *pm)
 {
    return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 ||
@@ -2919,6 +2965,12 @@ sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit)
  * height of 16 rows.  The width and height are stored in the FILEID and, being
  * non-zero, indicate a size file.
  *
+ * Because the PNG filter code is typically the largest CPU consumer within
+ * libpng itself there is a tendency to attempt to optimize it.  This results in
+ * special case code which needs to be validated.  To cause this to happen the
+ * 'size' images are made to use each possible filter, in so far as this is
+ * possible for smaller images.
+ *
  * For palette image (colour type 3) multiple transform images are stored with
  * the same bit depth to allow testing of more colour combinations -
  * particularly important for testing the gamma code because libpng uses a
@@ -3077,8 +3129,10 @@ init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette,
       for (; i<256; ++i)
          tRNS[i] = 24;
 
-      if (j > 0)
-         png_set_tRNS(pp, pi, tRNS, j, 0/*color*/);
+#     ifdef PNG_WRITE_tRNS_SUPPORTED
+         if (j > 0)
+            png_set_tRNS(pp, pi, tRNS, j, 0/*color*/);
+#     endif
    }
 }
 
@@ -3324,6 +3378,13 @@ transform_row(png_const_structp pp, png_byte buffer[TRANSFORM_ROWMAX],
  */
 #define DEPTH(bd) ((png_byte)(1U << (bd)))
 
+/* This is just a helper for compiling on minimal systems with no write
+ * interlacing support.
+ */
+#ifndef PNG_WRITE_INTERLACING_SUPPORTED
+#  define png_set_interlace_handling(a) (1)
+#endif
+
 /* Make a standardized image given a an image colour type, bit depth and
  * interlace type.  The standard images have a very restricted range of
  * rows and heights and are used for testing transforms rather than image
@@ -3477,8 +3538,12 @@ make_transform_images(png_store *ps)
    {
       int interlace_type;
 
-      for (interlace_type = PNG_INTERLACE_NONE;
-           interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
+#     ifdef PNG_WRITE_INTERLACING_SUPPORTED
+         for (interlace_type = PNG_INTERLACE_NONE;
+              interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
+#     else
+         interlace_type = PNG_INTERLACE_NONE;
+#     endif
       {
          char name[FILE_NAME_SIZE];
 
@@ -3634,6 +3699,9 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          int npasses = npasses_from_interlace_type(pp, interlace_type);
          png_uint_32 y;
          int pass;
+#        ifdef PNG_WRITE_FILTER_SUPPORTED
+            int nfilter = PNG_FILTER_VALUE_LAST;
+#        endif
          png_byte image[16][SIZE_ROWMAX];
 
          /* To help consistent error detection make the parts of this buffer
@@ -3687,7 +3755,24 @@ make_size_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
                      continue;
                }
 
-               /* Only get to here if the row has some pixels in it. */
+#           ifdef PNG_WRITE_FILTER_SUPPORTED
+               /* Only get to here if the row has some pixels in it, set the
+                * filters to 'all' for the very first row and thereafter to a
+                * single filter.  It isn't well documented, but png_set_filter
+                * does accept a filter number (per the spec) as well as a bit
+                * mask.
+                *
+                * The apparent wackiness of decrementing nfilter rather than
+                * incrementing is so that Paeth gets used in all images bigger
+                * than 1 row - it's the tricky one.
+                */
+               png_set_filter(pp, 0/*method*/,
+                  nfilter >= PNG_FILTER_VALUE_LAST ? PNG_ALL_FILTERS : nfilter);
+
+               if (nfilter-- == 0)
+                  nfilter = PNG_FILTER_VALUE_LAST-1;
+#           endif
+
                png_write_row(pp, row);
             }
          }
@@ -3754,8 +3839,10 @@ make_size(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type, int bdlo,
                width, height, 0);
             make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE,
                width, height, 1);
+#        ifdef PNG_WRITE_INTERLACING_SUPPORTED
             make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7,
                width, height, 0);
+#        endif
             make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7,
                width, height, 1);
          }
@@ -3950,8 +4037,12 @@ make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
    {
       int interlace_type;
 
-      for (interlace_type = PNG_INTERLACE_NONE;
-           interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
+#     ifdef PNG_WRITE_INTERLACING_SUPPORTED
+         for (interlace_type = PNG_INTERLACE_NONE;
+              interlace_type < PNG_INTERLACE_LAST; ++interlace_type)
+#     else
+         interlace_type = PNG_INTERLACE_NONE;
+#     endif
       {
          unsigned int test;
          char name[FILE_NAME_SIZE];
@@ -3972,7 +4063,7 @@ make_errors(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
 
    return 1; /* keep going */
 }
-#endif
+#endif /* PNG_WARNINGS_SUPPORTED */
 
 static void
 perform_error_test(png_modifier *pm)
@@ -5988,7 +6079,7 @@ transform_test(png_modifier *pmIn, PNG_CONST png_uint_32 idIn,
 
    Catch(fault)
    {
-      modifier_reset((png_modifier*)fault);
+      modifier_reset(voidcast(png_modifier*,(void*)fault));
    }
 }
 
@@ -7122,7 +7213,7 @@ transform_enable(PNG_CONST char *name)
    {
       fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n",
          name);
-      exit(1);
+      exit(99);
    }
 }
 
@@ -7144,7 +7235,7 @@ transform_disable(PNG_CONST char *name)
 
    fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n",
       name);
-   exit(1);
+   exit(99);
 }
 
 static void
@@ -8692,7 +8783,7 @@ gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
    }
 
    Catch(fault)
-      modifier_reset((png_modifier*)fault);
+      modifier_reset(voidcast(png_modifier*,(void*)fault));
 }
 
 static void gamma_threshold_test(png_modifier *pm, png_byte colour_type,
@@ -9448,7 +9539,7 @@ perform_interlace_macro_validation(void)
       if (m != f)
       {
          fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f);
-         exit(1);
+         exit(99);
       }
 
       m = PNG_PASS_START_COL(pass);
@@ -9456,7 +9547,7 @@ perform_interlace_macro_validation(void)
       if (m != f)
       {
          fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f);
-         exit(1);
+         exit(99);
       }
 
       m = PNG_PASS_ROW_SHIFT(pass);
@@ -9464,7 +9555,7 @@ perform_interlace_macro_validation(void)
       if (m != f)
       {
          fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f);
-         exit(1);
+         exit(99);
       }
 
       m = PNG_PASS_COL_SHIFT(pass);
@@ -9472,7 +9563,7 @@ perform_interlace_macro_validation(void)
       if (m != f)
       {
          fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f);
-         exit(1);
+         exit(99);
       }
 
       /* Macros that depend on the image or sub-image height too:
@@ -9493,7 +9584,7 @@ perform_interlace_macro_validation(void)
          {
             fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n",
                v, pass, m, f);
-            exit(1);
+            exit(99);
          }
 
          m = PNG_COL_FROM_PASS_COL(v, pass);
@@ -9502,7 +9593,7 @@ perform_interlace_macro_validation(void)
          {
             fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n",
                v, pass, m, f);
-            exit(1);
+            exit(99);
          }
 
          m = PNG_ROW_IN_INTERLACE_PASS(v, pass);
@@ -9511,7 +9602,7 @@ perform_interlace_macro_validation(void)
          {
             fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n",
                v, pass, m, f);
-            exit(1);
+            exit(99);
          }
 
          m = PNG_COL_IN_INTERLACE_PASS(v, pass);
@@ -9520,7 +9611,7 @@ perform_interlace_macro_validation(void)
          {
             fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n",
                v, pass, m, f);
-            exit(1);
+            exit(99);
          }
 
          /* Then the base 1 stuff: */
@@ -9531,7 +9622,7 @@ perform_interlace_macro_validation(void)
          {
             fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n",
                v, pass, m, f);
-            exit(1);
+            exit(99);
          }
 
          m = PNG_PASS_COLS(v, pass);
@@ -9540,7 +9631,7 @@ perform_interlace_macro_validation(void)
          {
             fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n",
                v, pass, m, f);
-            exit(1);
+            exit(99);
          }
 
          /* Move to the next v - the stepping algorithm starts skipping
@@ -9944,7 +10035,7 @@ int main(int argc, char **argv)
          else
          {
             fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv);
-            exit(1);
+            exit(99);
          }
 
          catmore = 1;
@@ -9956,10 +10047,51 @@ int main(int argc, char **argv)
       else if (strcmp(*argv, "--log16") == 0)
          --argc, pm.log16 = atof(*++argv), catmore = 1;
 
+#ifdef PNG_SET_OPTION_SUPPORTED
+      else if (strncmp(*argv, "--option=", 9) == 0)
+      {
+         /* Syntax of the argument is <option>:{on|off} */
+         const char *arg = 9+*argv;
+         unsigned char option=0, setting=0;
+
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+         if (strncmp(arg, "arm-neon:", 9) == 0)
+            option = PNG_ARM_NEON, arg += 9;
+
+         else
+#endif
+         if (strncmp(arg, "max-inflate-window:", 19) == 0)
+            option = PNG_MAXIMUM_INFLATE_WINDOW, arg += 19;
+
+         else
+         {
+            fprintf(stderr, "pngvalid: %s: %s: unknown option\n", *argv, arg);
+            exit(99);
+         }
+
+         if (strcmp(arg, "off") == 0)
+            setting = PNG_OPTION_OFF;
+
+         else if (strcmp(arg, "on") == 0)
+            setting = PNG_OPTION_ON;
+
+         else
+         {
+            fprintf(stderr,
+               "pngvalid: %s: %s: unknown setting (use 'on' or 'off')\n",
+               *argv, arg);
+            exit(99);
+         }
+
+         pm.this.options[pm.this.noptions].option = option;
+         pm.this.options[pm.this.noptions++].setting = setting;
+      }
+#endif /* PNG_SET_OPTION_SUPPORTED */
+
       else
       {
          fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv);
-         exit(1);
+         exit(99);
       }
 
       if (catmore) /* consumed an extra *argv */
@@ -10133,12 +10265,16 @@ int main(int argc, char **argv)
       }
    }
 
+   /* This is required because some very minimal configurations do not use it:
+    */
+   UNUSED(fail)
    return 0;
 }
-#else /* write not supported */
+#else /* write or low level APIs not supported */
 int main(void)
 {
-   fprintf(stderr, "pngvalid: no write support in libpng, all tests skipped\n");
+   fprintf(stderr,
+      "pngvalid: no low level write support in libpng, all tests skipped\n");
    /* So the test is skipped: */
    return 77;
 }

contrib/pngminim/decoder/makefile

@@ -15,7 +15,7 @@ RM=rm -f
 COPY=cp
 
 CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
-CFLAGS=-O1
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -100,12 +100,12 @@ $(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\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) pngm2pnm$(O)
 	$(RM) pngm2pnm$(E)

contrib/pngminim/encoder/makefile

@@ -15,7 +15,7 @@ RM=rm -f
 COPY=cp
 
 CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
-CFLAGS=-O1
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -99,12 +99,12 @@ $(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\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) pnm2pngm$(O)
 	$(RM) pnm2pngm$(E)

contrib/pngminim/encoder/pngusr.dfa

@@ -13,9 +13,10 @@ everything = off
 # Switch on the write code - this makes a minimalist encoder
 
 option WRITE on
-# These 2 options are required if you need to read PGM (P1 or P4) PGM files.
-# option WRITE_INVERT on
-# option WRITE_PACK on
+
+# These 2 options are required if you need to read PBM (P1 or P4) files.
+option WRITE_INVERT on
+option WRITE_PACK on
 
 # You must choose fixed or floating point arithmetic:
 # option FLOATING_POINT on

contrib/pngminim/preader/makefile

@@ -31,7 +31,7 @@ XLIB = -L/usr/X11R6/lib -lX11
 LIBS = $(XLIB) -lm                      #platforms that need libm
 
 CPPFLAGS=-I. $(XINC) -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
-CFLAGS=-O1
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -115,12 +115,12 @@ $(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\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) rpng2-x$(O)
 	$(RM) rpng2-x$(E)

contrib/tools/pngfix.c

@@ -2,7 +2,7 @@
  *
  * Copyright (c) 2013 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.3 [July 18, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -15,6 +15,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <ctype.h>
+#include <limits.h>
 #include <errno.h>
 #include <assert.h>
 
@@ -49,8 +50,31 @@
 #  error "pngfix will not work with libpng prior to 1.6.3"
 #endif
 
-#ifdef PNG_READ_SUPPORTED
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_EASY_ACCESS_SUPPORTED)
+/* zlib.h defines the structure z_stream, an instance of which is included
+ * in this structure and is required for decompressing the LZ compressed
+ * data in PNG files.
+ */
+#ifndef ZLIB_CONST
+   /* We must ensure that zlib uses 'const' in declarations. */
+#  define ZLIB_CONST
+#endif
 #include <zlib.h>
+#ifdef const
+   /* zlib.h sometimes #defines const to nothing, undo this. */
+#  undef const
+#endif
+
+/* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
+ * with older builds.
+ */
+#if ZLIB_VERNUM < 0x1260
+#  define PNGZ_MSG_CAST(s) png_constcast(char*,s)
+#  define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
+#else
+#  define PNGZ_MSG_CAST(s) (s)
+#  define PNGZ_INPUT_CAST(b) (b)
+#endif
 
 #ifndef PNG_MAXIMUM_INFLATE_WINDOW
 #  error "pngfix not supported in this libpng version"
@@ -118,6 +142,11 @@
 /* Is it safe to copy? */
 #define SAFE_TO_COPY(chunk) (((chunk) & PNG_U32(0,0,0,32)) != 0)
 
+/* Fix ups for builds with limited read support */
+#ifndef PNG_ERROR_TEXT_SUPPORTED
+#  define png_error(a,b) png_err(a)
+#endif
+
 /********************************* UTILITIES **********************************/
 /* UNREACHED is a value to cause an assert to fail. Because of the way the
  * assert macro is written the string "UNREACHED" is produced in the error
@@ -885,10 +914,10 @@ emit_string(const char *str, FILE *out)
     */
 {
    for (; *str; ++str)
-      if (isgraph(*str))
+      if (isgraph(UCHAR_MAX & *str))
          putc(*str, out);
 
-      else if (isspace(*str))
+      else if (isspace(UCHAR_MAX & *str))
          putc('_', out);
    
       else
@@ -1546,7 +1575,7 @@ chunk_end(struct chunk **chunk_var)
 }
 
 static void
-chunk_init(struct chunk *chunk, struct file *file)
+chunk_init(struct chunk * const chunk, struct file * const file)
    /* When a chunk is initialized the file length/type/pos are copied into the
     * corresponding chunk fields and the new chunk is registered in the file
     * structure.  There can only be one chunk at a time.
@@ -1755,7 +1784,7 @@ IDAT_end(struct IDAT **idat_var)
 }
 
 static void
-IDAT_init(struct IDAT *idat, struct file *file)
+IDAT_init(struct IDAT * const idat, struct file * const file)
    /* When the chunk is png_IDAT instantiate an IDAT control structure in place
     * of a chunk control structure.  The IDAT will instantiate a chunk control
     * structure using the file alloc routine.
@@ -2636,7 +2665,7 @@ zlib_check(struct file *file, png_uint_32 offset)
 
          case ZLIB_OK:
             /* Truncated stream; unrecoverable, gets converted to ZLIB_FATAL */
-            zlib.z.msg = png_constcast(char*, "[truncated]");
+            zlib.z.msg = PNGZ_MSG_CAST("[truncated]");
             zlib_message(&zlib, 0/*expected*/);
             /* FALL THROUGH */
 
@@ -2675,7 +2704,7 @@ zlib_check(struct file *file, png_uint_32 offset)
 
                      /* Output the error that wasn't output before: */
                      if (zlib.z.msg == NULL)
-                        zlib.z.msg = png_constcast(char*,
+                        zlib.z.msg = PNGZ_MSG_CAST(
                            "invalid distance too far back");
                      zlib_message(&zlib, 0/*stream error*/);
                      zlib_end(&zlib);
@@ -3294,6 +3323,8 @@ read_callback(png_structp png_ptr, png_bytep buffer, size_t count)
 
             else
             {
+               assert(chunk != NULL);
+
                /* Set up for write, notice that repositioning the input stream
                 * is only necessary if something is to be read from it.  Also
                 * notice that for the IDAT stream this must only happen once -
@@ -3307,6 +3338,8 @@ read_callback(png_structp png_ptr, png_bytep buffer, size_t count)
             /* FALL THROUGH */
 
          default:
+            assert(chunk != NULL);
+
             /* NOTE: the arithmetic below overflows and gives a large positive
              * png_uint_32 value until the whole chunk data has been written.
              */
@@ -3512,22 +3545,14 @@ allocate(struct file *file, int allocate_idat)
 
    if (allocate_idat)
    {
-      struct IDAT *idat;
-
       assert(file->idat == NULL);
-      idat = &control->idat;
-      IDAT_init(idat, file);
-      file->idat = idat;
+      IDAT_init(&control->idat, file);
    }
 
    else /* chunk */
    {
-      struct chunk *chunk;
-
       assert(file->chunk == NULL);
-      chunk = &control->chunk;
-      chunk_init(chunk, file);
-      file->chunk = chunk;
+      chunk_init(&control->chunk, file);
    }
 }
 
@@ -3620,7 +3645,7 @@ read_png(struct control *control)
    return rc;
 }
 
-static void
+static int
 one_file(struct global *global, const char *file_name, const char *out_name)
 {
    int rc;
@@ -3639,6 +3664,8 @@ one_file(struct global *global, const char *file_name, const char *out_name)
       rc = read_png(&control);
 
    rc |= control_end(&control);
+
+   return rc;
 }
 
 static void
@@ -4007,4 +4034,4 @@ main(void)
    fprintf(stderr, "pngfix does not work without read support\n");
    return 77;
 }
-#endif /* PNG_READ_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED && PNG_EASY_ACCESS_SUPPORTED */

libpng-manual.txt

@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.4 - September 12, 2013
+ libpng version 1.6.8 - December 19, 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 1.6.4 - September 12, 2013
+ libpng versions 0.97, January 1998, through 1.6.8 - December 19, 2013
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
@@ -4622,11 +4622,11 @@ XI.  Changes to Libpng from version 1.4.x to 1.5.x
 From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
 function) incorrectly returned a value of type png_uint_32.
 
-Checking for invalid palette index on read or write was added at libpng
-1.5.10.  When an invalid index is found, libpng issues a benign error.
-This is enabled by default because this condition is an error according
-to the PNG specification, Clause 11.3.2, but the error can be ignored in
-each png_ptr with
+Checking for invalid palette index on write was added at libpng
+1.5.10.  If a pixel contains an invalid (out-of-range) index libpng issues
+a benign error.  This is enabled by default because this condition is an
+error according to the PNG specification, Clause 11.3.2, but the error can
+be ignored in each png_ptr with
 
    png_set_check_for_invalid_index(png_ptr, allowed);
 
@@ -5015,10 +5015,11 @@ where "rp" indicates a "restricted pointer".
 
 Error detection in some chunks has improved; in particular the iCCP chunk
 reader now does pretty complete validation of the basic format.  Some bad
-profiles that were previously accepted are now rejected, in particular the
-very old broken Microsoft/HP sRGB profile.  The PNG spec requirement that
-only grayscale profiles may appear in images with color type 0 or 4 and that
-even if the image only contains gray pixels, only RGB profiles may appear
+profiles that were previously accepted are now accepted with a warning or
+rejected, depending upon the png_set_benign_errors() setting, in particular the
+very old broken Microsoft/HP 3144-byte sRGB profile.  The PNG spec requirement
+that only grayscale profiles may appear in images with color type 0 or 4 and
+that 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.
 
@@ -5027,7 +5028,9 @@ 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().
+transform after it calls png_read_update_info() or if it attempts to call
+both png_read_update_info() and png_start_read_image() or to call either
+of them more than once.
 
 The default condition for benign_errors is now to treat benign errors as
 warnings while reading and as errors while writing.
@@ -5048,18 +5051,19 @@ 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
+Libpng-1.6.0 through 1.6.2 used 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 caused
+libpng to issue a "too far back" error and reject the file.  Libpng-1.6.3 and
+later calculate their own safe CMF from the image dimensions, provide 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
+and provide 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
@@ -5229,13 +5233,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 XVI. Y2K Compliance in libpng
 
-September 12, 2013
+December 19, 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 1.6.4 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.8 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 "September 12, 2013"
+.TH LIBPNG 3 "December 19, 2013"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.4
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.8
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -504,7 +504,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.4 - September 12, 2013
+ libpng version 1.6.8 - December 19, 2013
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
@@ -515,7 +515,7 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.4 - September 12, 2013
+ libpng versions 0.97, January 1998, through 1.6.8 - December 19, 2013
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
@@ -5127,11 +5127,11 @@ We removed the trailing '.' from the warning and error messages.
 From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
 function) incorrectly returned a value of type png_uint_32.
 
-Checking for invalid palette index on read or write was added at libpng
-1.5.10.  When an invalid index is found, libpng issues a benign error.
-This is enabled by default because this condition is an error according
-to the PNG specification, Clause 11.3.2, but the error can be ignored in
-each png_ptr with
+Checking for invalid palette index on write was added at libpng
+1.5.10.  If a pixel contains an invalid (out-of-range) index libpng issues
+a benign error.  This is enabled by default because this condition is an
+error according to the PNG specification, Clause 11.3.2, but the error can
+be ignored in each png_ptr with
 
    png_set_check_for_invalid_index(png_ptr, allowed);
 
@@ -5520,10 +5520,11 @@ where "rp" indicates a "restricted pointer".
 
 Error detection in some chunks has improved; in particular the iCCP chunk
 reader now does pretty complete validation of the basic format.  Some bad
-profiles that were previously accepted are now rejected, in particular the
-very old broken Microsoft/HP sRGB profile.  The PNG spec requirement that
-only grayscale profiles may appear in images with color type 0 or 4 and that
-even if the image only contains gray pixels, only RGB profiles may appear
+profiles that were previously accepted are now accepted with a warning or
+rejected, depending upon the png_set_benign_errors() setting, in particular the
+very old broken Microsoft/HP 3144-byte sRGB profile.  The PNG spec requirement
+that only grayscale profiles may appear in images with color type 0 or 4 and
+that 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.
 
@@ -5532,7 +5533,9 @@ 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().
+transform after it calls png_read_update_info() or if it attempts to call
+both png_read_update_info() and png_start_read_image() or to call either
+of them more than once.
 
 The default condition for benign_errors is now to treat benign errors as
 warnings while reading and as errors while writing.
@@ -5553,18 +5556,19 @@ 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
+Libpng-1.6.0 through 1.6.2 used 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 caused
+libpng to issue a "too far back" error and reject the file.  Libpng-1.6.3 and
+later calculate their own safe CMF from the image dimensions, provide 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
+and provide 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
@@ -5734,13 +5738,13 @@ Other rules can be inferred by inspecting the libpng source.
 
 .SH XVI. Y2K Compliance in libpng
 
-September 12, 2013
+December 19, 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 1.6.4 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.8 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
@@ -5960,6 +5964,14 @@ the first widely used release:
  1.6.4beta01-02      16    10604  16.so.16.4[.0]
  1.6.4rc01           16    10604  16.so.16.4[.0]
  1.6.4               16    10604  16.so.16.4[.0]
+ 1.6.5               16    10605  16.so.16.5[.0]
+ 1.6.6               16    10606  16.so.16.6[.0]
+ 1.6.7beta01-04      16    10607  16.so.16.7[.0]
+ 1.6.7rc01-02        16    10607  16.so.16.7[.0]
+ 1.6.7               16    10607  16.so.16.7[.0]
+ 1.6.8beta01-02      16    10608  16.so.16.8[.0]
+ 1.6.8rc01-02        16    10608  16.so.16.8[.0]
+ 1.6.8               16    10608  16.so.16.8[.0]
 
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -6016,7 +6028,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.4 - September 12, 2013:
+Libpng version 1.6.8 - December 19, 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).
 
@@ -6039,7 +6051,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.4, September 12, 2013, are
+libpng versions 1.2.6, August 15, 2004, through 1.6.8, December 19, 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
@@ -6138,7 +6150,7 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-September 12, 2013
+December 19, 2013
 
 .\" end of man page
 

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "September 12, 2013"
+.TH LIBPNGPF 3 "December 19, 2013"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.4
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.8
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "September 12, 2013"
+.TH PNG 5 "December 19, 2013"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION

png.c

@@ -1,7 +1,7 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.6.2 [April 25, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -14,7 +14,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_4 Your_png_h_is_not_version_1_6_4;
+typedef png_libpng_version_1_6_8 Your_png_h_is_not_version_1_6_8;
 
 /* 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
@@ -201,6 +201,7 @@ png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
          pos = png_safecat(m, (sizeof m), pos, user_png_ver);
          pos = png_safecat(m, (sizeof m), pos, " but running with ");
          pos = png_safecat(m, (sizeof m), pos, png_libpng_ver);
+         PNG_UNUSED(pos)
 
          png_warning(png_ptr, m);
 #endif
@@ -259,6 +260,10 @@ png_create_png_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
     */
 #  ifdef PNG_USER_MEM_SUPPORTED
       png_set_mem_fn(&create_struct, mem_ptr, malloc_fn, free_fn);
+#  else
+      PNG_UNUSED(mem_ptr)
+      PNG_UNUSED(malloc_fn)
+      PNG_UNUSED(free_fn)
 #  endif
 
    /* (*error_fn) can return control to the caller after the error_ptr is set,
@@ -768,13 +773,13 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.6.4 - September 12, 2013" PNG_STRING_NEWLINE \
+     "libpng version 1.6.8 - December 19, 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 1.6.4 - September 12, 2013\
+      return "libpng version 1.6.8 - December 19, 2013\
       Copyright (c) 1998-2013 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -855,7 +860,8 @@ png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name)
    return PNG_HANDLE_CHUNK_AS_DEFAULT;
 }
 
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
+   defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
 int /* PRIVATE */
 png_chunk_unknown_handling(png_const_structrp png_ptr, png_uint_32 chunk_name)
 {
@@ -864,7 +870,7 @@ 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 /* HANDLE_AS_UNKNOWN */
+#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
 #endif /* SET_UNKNOWN_CHUNKS */
 
 #ifdef PNG_READ_SUPPORTED
@@ -1721,6 +1727,7 @@ png_icc_profile_error(png_const_structrp png_ptr, png_colorspacerp colorspace,
 #  endif
    /* The 'reason' is an arbitrary message, allow +79 maximum 195 */
    pos = png_safecat(message, (sizeof message), pos, reason);
+   PNG_UNUSED(pos)
 
    /* This is recoverable, but make it unconditionally an app_error on write to
     * avoid writing invalid ICC profiles into PNG files.  (I.e.  we handle them
@@ -3090,11 +3097,15 @@ png_fixed(png_const_structrp png_ptr, double fp, png_const_charp text)
    if (r > 2147483647. || r < -2147483648.)
       png_fixed_error(png_ptr, text);
 
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(text)
+#  endif
+
    return (png_fixed_point)r;
 }
 #endif
 
-#if defined(PNG_READ_GAMMA_SUPPORTED) || \
+#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_COLORSPACE_SUPPORTED) ||\
     defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
 /* muldiv functions */
 /* This API takes signed arguments and rounds the result to the nearest
@@ -3267,27 +3278,29 @@ png_gamma_significant(png_fixed_point gamma_val)
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
+#  ifdef PNG_16BIT_SUPPORTED
 /* A local convenience routine. */
 static png_fixed_point
 png_product2(png_fixed_point a, png_fixed_point b)
 {
    /* The required result is 1/a * 1/b; the following preserves accuracy. */
-#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+#    ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
    double r = a * 1E-5;
    r *= b;
    r = floor(r+.5);
 
    if (r <= 2147483647. && r >= -2147483648.)
       return (png_fixed_point)r;
-#else
+#    else
    png_fixed_point res;
 
    if (png_muldiv(&res, a, b, 100000))
       return res;
-#endif
+#    endif
 
    return 0; /* overflow */
 }
+#  endif /* 16BIT */
 
 /* The inverse of the above. */
 png_fixed_point
@@ -3592,6 +3605,7 @@ png_exp8bit(png_fixed_point lg2)
    return (png_byte)((x + 0x7fffffU) >> 24);
 }
 
+#ifdef PNG_16BIT_SUPPORTED
 static png_uint_16
 png_exp16bit(png_fixed_point lg2)
 {
@@ -3602,6 +3616,7 @@ png_exp16bit(png_fixed_point lg2)
    x -= x >> 16;
    return (png_uint_16)((x + 32767U) >> 16);
 }
+#endif /* 16BIT */
 #endif /* FLOATING_ARITHMETIC */
 
 png_byte
@@ -3627,6 +3642,7 @@ png_gamma_8bit_correct(unsigned int value, png_fixed_point gamma_val)
    return (png_byte)value;
 }
 
+#ifdef PNG_16BIT_SUPPORTED
 png_uint_16
 png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
 {
@@ -3649,6 +3665,7 @@ png_gamma_16bit_correct(unsigned int value, png_fixed_point gamma_val)
 
    return (png_uint_16)value;
 }
+#endif /* 16BIT */
 
 /* This does the right thing based on the bit_depth field of the
  * png_struct, interpreting values as 8-bit or 16-bit.  While the result
@@ -3662,10 +3679,16 @@ png_gamma_correct(png_structrp png_ptr, unsigned int value,
    if (png_ptr->bit_depth == 8)
       return png_gamma_8bit_correct(value, gamma_val);
 
+#ifdef PNG_16BIT_SUPPORTED
    else
       return png_gamma_16bit_correct(value, gamma_val);
+#else
+      /* should not reach this */
+      return 0;
+#endif /* 16BIT */
 }
 
+#ifdef PNG_16BIT_SUPPORTED
 /* Internal function to build a single 16-bit table - the table consists of
  * 'num' 256 entry subtables, where 'num' is determined by 'shift' - the amount
  * to shift the input values right (or 16-number_of_signifiant_bits).
@@ -3804,6 +3827,7 @@ png_build_16to8_table(png_structrp png_ptr, png_uint_16pp *ptable,
       last++;
    }
 }
+#endif /* 16BIT */
 
 /* Build a single 8-bit table: same as the 16-bit case but much simpler (and
  * typically much faster).  Note that libpng currently does no sBIT processing
@@ -3832,6 +3856,7 @@ png_destroy_gamma_table(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->gamma_table);
    png_ptr->gamma_table = NULL;
 
+#ifdef PNG_16BIT_SUPPORTED
    if (png_ptr->gamma_16_table != NULL)
    {
       int i;
@@ -3843,6 +3868,7 @@ png_destroy_gamma_table(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->gamma_16_table);
    png_ptr->gamma_16_table = NULL;
    }
+#endif /* 16BIT */
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
    defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
@@ -3852,6 +3878,7 @@ png_destroy_gamma_table(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->gamma_to_1);
    png_ptr->gamma_to_1 = NULL;
 
+#ifdef PNG_16BIT_SUPPORTED
    if (png_ptr->gamma_16_from_1 != NULL)
    {
       int i;
@@ -3874,6 +3901,7 @@ png_destroy_gamma_table(png_structrp png_ptr)
    png_free(png_ptr, png_ptr->gamma_16_to_1);
    png_ptr->gamma_16_to_1 = NULL;
    }
+#endif /* 16BIT */
 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
 }
 
@@ -3919,6 +3947,7 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
      }
 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
   }
+#ifdef PNG_16BIT_SUPPORTED
   else
   {
      png_byte shift, sig_bit;
@@ -3975,24 +4004,20 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
 
      png_ptr->gamma_shift = shift;
 
-#ifdef PNG_16BIT_SUPPORTED
      /* NOTE: prior to 1.5.4 this test used to include PNG_BACKGROUND (now
       * PNG_COMPOSE).  This effectively smashed the background calculation for
       * 16-bit output because the 8-bit table assumes the result will be reduced
       * to 8 bits.
       */
      if (png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8))
-#endif
          png_build_16to8_table(png_ptr, &png_ptr->gamma_16_table, shift,
          png_ptr->screen_gamma > 0 ? png_product2(png_ptr->colorspace.gamma,
          png_ptr->screen_gamma) : PNG_FP_1);
 
-#ifdef PNG_16BIT_SUPPORTED
      else
          png_build_16bit_table(png_ptr, &png_ptr->gamma_16_table, shift,
          png_ptr->screen_gamma > 0 ? png_reciprocal2(png_ptr->colorspace.gamma,
          png_ptr->screen_gamma) : PNG_FP_1);
-#endif
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
    defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
@@ -4012,6 +4037,7 @@ png_build_gamma_table(png_structrp png_ptr, int bit_depth)
      }
 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
   }
+#endif /* 16BIT */
 }
 #endif /* READ_GAMMA */
 

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.4 - September 12, 2013
+ * libpng version 1.6.8 - December 19, 2013
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -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 1.6.4 - September 12, 2013: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.8 - December 19, 2013: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -181,6 +181,14 @@
  *    1.6.4beta01-02          16    10604  16.so.16.4[.0]
  *    1.6.4rc01               16    10604  16.so.16.4[.0]
  *    1.6.4                   16    10604  16.so.16.4[.0]
+ *    1.6.5                   16    10605  16.so.16.5[.0]
+ *    1.6.6                   16    10606  16.so.16.6[.0]
+ *    1.6.7beta01-04          16    10607  16.so.16.7[.0]
+ *    1.6.7rc01-03            16    10607  16.so.16.7[.0]
+ *    1.6.7                   16    10607  16.so.16.7[.0]
+ *    1.6.8beta01-02          16    10608  16.so.16.8[.0]
+ *    1.6.8rc01-02            16    10608  16.so.16.8[.0]
+ *    1.6.8                   16    10608  16.so.16.8[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -212,7 +220,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.4, September 12, 2013, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.8, December 19, 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:
@@ -324,13 +332,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    September 12, 2013
+ *    December 19, 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 1.6.4 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.8 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
@@ -390,9 +398,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.4"
+#define PNG_LIBPNG_VER_STRING "1.6.8"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.4 - September 12, 2013\n"
+     " libpng version 1.6.8 - December 19, 2013\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -400,7 +408,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 4
+#define PNG_LIBPNG_VER_RELEASE 8
 
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
@@ -431,7 +439,7 @@
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10604 /* 1.6.4 */
+#define PNG_LIBPNG_VER 10608 /* 1.6.8 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -536,7 +544,7 @@ extern "C" {
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_6_4;
+typedef char* png_libpng_version_1_6_8;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -718,7 +726,8 @@ typedef png_time * png_timep;
 typedef const png_time * png_const_timep;
 typedef png_time * * png_timepp;
 
-#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
+   defined(PNG_USER_CHUNKS_SUPPORTED)
 /* png_unknown_chunk is a structure to hold queued chunks for which there is
  * no specific support.  The idea is that we can use this to queue
  * up private chunks for output even though the library doesn't actually

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.4 - September 12, 2013
+ * libpng version 1.6.8 - December 19, 2013
  *
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)

pngdebug.h

@@ -1,11 +1,11 @@
 
 /* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
  *
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -25,7 +25,7 @@
  *   (actually ((void)0)).
  *
  *   level: level of detail of message, starting at 0.  A level 'n'
- *          message is preceded by 'n' tab characters (not implemented
+ *          message is preceded by 'n' 3-space indentations (not implemented
  *          on Microsoft compilers unless PNG_DEBUG_FILE is also
  *          defined, to allow debug DLL compilation with no standard IO).
  *   message: a printf(3) style text string.  A trailing '\n' is added
@@ -77,32 +77,29 @@
 #      endif /* PNG_DEBUG_FILE */
 
 #      if (PNG_DEBUG > 1)
-/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on
- * non-ISO compilers
- */
 #        ifdef __STDC__
 #          ifndef png_debug
 #            define png_debug(l,m) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : "")))); \
        } while (0)
 #          endif
 #          ifndef png_debug1
 #            define png_debug1(l,m,p1) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1); \
        } while (0)
 #          endif
 #          ifndef png_debug2
 #            define png_debug2(l,m,p1,p2) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1,p2);\
        } while (0)
 #          endif
 #        else /* __STDC __ */

pngerror.c

@@ -1,7 +1,7 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -382,6 +382,10 @@ png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
 #     endif
       png_error(png_ptr, error_message);
    }
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 
 void /* PRIVATE */
@@ -391,6 +395,10 @@ png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
      png_warning(png_ptr, error_message);
   else
      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 
 void /* PRIVATE */
@@ -400,6 +408,10 @@ png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
      png_warning(png_ptr, error_message);
   else
      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 #endif /* BENIGN_ERRORS */
 
@@ -416,7 +428,8 @@ static PNG_CONST char png_digit[16] = {
 };
 
 #define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
-#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
 static void /* PRIVATE */
 png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
     error_message)
@@ -506,6 +519,10 @@ png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
 
    else
       png_chunk_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 #endif
 #endif /* PNG_READ_SUPPORTED */
@@ -513,6 +530,10 @@ png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
 void /* PRIVATE */
 png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
 {
+#  ifndef PNG_WARNINGS_SUPPORTED
+      PNG_UNUSED(message)
+#  endif
+
    /* This is always supported, but for just read or just write it
     * unconditionally does the right thing.
     */

pngmem.c

@@ -1,7 +1,7 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.6.0 [February 14, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -73,9 +73,10 @@ png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
     * to implement a user memory handler.  This checks to be sure it isn't
     * called with big numbers.
     */
-#ifdef PNG_USER_MEM_SUPPORTED
+#ifndef PNG_USER_MEM_SUPPORTED
    PNG_UNUSED(png_ptr)
 #endif
+
    if (size > 0 && size <= PNG_SIZE_MAX
 #     ifdef PNG_MAX_MALLOC_64K
          && size <= 65536U
@@ -95,6 +96,8 @@ png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
       return NULL;
 }
 
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
 /* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
  * that arises because of the checks in png_realloc_array that are repeated in
  * png_malloc_array.
@@ -156,6 +159,7 @@ png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
 
    return NULL; /* error */
 }
+#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */
 
 /* Various functions that have different error handling are derived from this.
  * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate

pngpread.c

@@ -1,7 +1,7 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.6.0 [February 14, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -285,8 +285,8 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
       if (chunk_name == png_PLTE)
          png_ptr->mode |= PNG_HAVE_PLTE;
    }
-
 #endif
+
    else if (chunk_name == png_PLTE)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
@@ -528,8 +528,8 @@ png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 
       png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
-
 #endif
+
    else
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)

pngpriv.h

@@ -6,7 +6,7 @@
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.6.3 [July 18, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -112,9 +112,15 @@
     * 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:
+    * disable use of NEON instructions.
+    *
+    * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
+    * can only be turned on automatically if that is supported too.  If
+    * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
+    * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
+    * off.
     */
-#  ifdef __ARM_NEON__
+#  if defined(__ARM_NEON__) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
 #     define PNG_ARM_NEON_OPT 2
 #  else
 #     define PNG_ARM_NEON_OPT 0
@@ -126,7 +132,49 @@
     * callbacks to do this.
     */
 #  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
-#endif
+
+   /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
+    * if possible - if __ARM_NEON__ is set and the compiler version is not known
+    * to be broken.  This is control by PNG_ARM_NEON_IMPLEMENTATION which can
+    * be:
+    *
+    *    1  The intrinsics code (the default with __ARM_NEON__)
+    *    2  The hand coded assembler (the default without __ARM_NEON__)
+    *
+    * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
+    * this is *NOT* supported and may cease to work even after a minor revision
+    * to libpng.  It *is* valid to do this for testing purposes, e.g. speed
+    * testing or a new compiler, but the results should be communicated to the
+    * libpng implementation list for incorporation in the next minor release.
+    */
+#  ifndef PNG_ARM_NEON_IMPLEMENTATION
+#     ifdef __ARM_NEON__
+#        if defined(__clang__)
+            /* At present it is unknown by the libpng developers which versions
+             * of clang support the intrinsics, however some or perhaps all
+             * versions do not work with the assembler so this may be
+             * irrelevant, so just use the default (do nothing here.)
+             */
+#        elif defined(__GNUC__)
+            /* GCC 4.5.4 NEON support is known to be broken.  4.6.3 is known to
+             * work, so if this *is* GCC, or G++, look for a version >4.5
+             */
+#           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
+#              define PNG_ARM_NEON_IMPLEMENTATION 2
+#           endif /* no GNUC support */
+#        endif /* __GNUC__ */
+#     else /* !defined __ARM_NEON__ */
+         /* The 'intrinsics' code simply won't compile without this -mfpu=neon:
+          */
+#        define PNG_ARM_NEON_IMPLEMENTATION 2
+#     endif /* __ARM_NEON__ */
+#  endif /* !defined PNG_ARM_NEON_IMPLEMENTATION */
+
+#  ifndef PNG_ARM_NEON_IMPLEMENTATION
+      /* Use the intrinsics code by default. */
+#     define PNG_ARM_NEON_IMPLEMENTATION 1
+#  endif
+#endif /* PNG_ARM_NEON_OPT > 0 */
 
 /* 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
@@ -1176,7 +1224,7 @@ PNG_INTERNAL_FUNCTION(void,png_read_finish_IDAT,(png_structrp png_ptr),
 PNG_INTERNAL_FUNCTION(void,png_read_finish_row,(png_structrp png_ptr),
    PNG_EMPTY);
    /* Finish a row while reading, dealing with interlacing passes, etc. */
-#endif
+#endif /* PNG_SEQUENTIAL_READ_SUPPORTED */
 
 /* Initialize the row buffers, etc. */
 PNG_INTERNAL_FUNCTION(void,png_read_start_row,(png_structrp png_ptr),PNG_EMPTY);
@@ -1422,7 +1470,6 @@ PNG_INTERNAL_FUNCTION(void,png_handle_zTXt,(png_structrp png_ptr,
 PNG_INTERNAL_FUNCTION(void,png_check_chunk_name,(png_structrp png_ptr,
     png_uint_32 chunk_name),PNG_EMPTY);
 
-#ifdef PNG_READ_SUPPORTED
 PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
     png_inforp info_ptr, png_uint_32 length, int keep),PNG_EMPTY);
    /* This is the function that gets called for unknown chunks.  The 'keep'
@@ -1431,14 +1478,14 @@ PNG_INTERNAL_FUNCTION(void,png_handle_unknown,(png_structrp png_ptr,
     * just skips the chunk or errors out if it is critical.
     */
 
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) ||\
+    defined(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 /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED */
+#endif /* READ_UNKNOWN_CHUNKS || HANDLE_AS_UNKNOWN */
 
 /* Handle the transformations for reading and writing */
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
@@ -1857,7 +1904,7 @@ PNG_INTERNAL_FUNCTION(int,png_check_fp_string,(png_const_charp string,
    png_size_t size),PNG_EMPTY);
 #endif /* pCAL || sCAL */
 
-#if defined(PNG_READ_GAMMA_SUPPORTED) ||\
+#if defined(PNG_GAMMA_SUPPORTED) ||\
     defined(PNG_INCH_CONVERSIONS_SUPPORTED) || defined(PNG_READ_pHYs_SUPPORTED)
 /* Added at libpng version 1.5.0 */
 /* This is a utility to provide a*times/div (rounded) and indicate

pngread.c

@@ -1,7 +1,7 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1125,12 +1125,11 @@ png_read_png(png_structrp png_ptr, png_inforp info_ptr,
 /* Arguments to png_image_finish_read: */
 
 /* Encoding of PNG data (used by the color-map code) */
-/* TODO: change these, dang, ANSI-C reserves the 'E' namespace. */
-#  define E_NOTSET  0 /* File encoding not yet known */
-#  define E_sRGB    1 /* 8-bit encoded to sRGB gamma */
-#  define E_LINEAR  2 /* 16-bit linear: not encoded, NOT pre-multiplied! */
-#  define E_FILE    3 /* 8-bit encoded to file gamma, not sRGB or linear */
-#  define E_LINEAR8 4 /* 8-bit linear: only from a file value */
+#  define P_NOTSET  0 /* File encoding not yet known */
+#  define P_sRGB    1 /* 8-bit encoded to sRGB gamma */
+#  define P_LINEAR  2 /* 16-bit linear: not encoded, NOT pre-multiplied! */
+#  define P_FILE    3 /* 8-bit encoded to file gamma, not sRGB or linear */
+#  define P_LINEAR8 4 /* 8-bit linear: only from a file value */
 
 /* Color-map processing: after libpng has run on the PNG image further
  * processing may be needed to conver the data to color-map indicies.
@@ -1161,7 +1160,7 @@ typedef struct
    png_voidp       first_row;
    ptrdiff_t       row_bytes;           /* step between rows */
    int             file_encoding;       /* E_ values above */
-   png_fixed_point gamma_to_linear;     /* For E_FILE, reciprocal of gamma */
+   png_fixed_point gamma_to_linear;     /* For P_FILE, reciprocal of gamma */
    int             colormap_processing; /* PNG_CMAP_ values above */
 } png_image_read_control;
 
@@ -1293,7 +1292,7 @@ png_image_read_header(png_voidp argument)
 #ifdef PNG_COLORSPACE_SUPPORTED
       /* Does the colorspace match sRGB?  If there is no color endpoint
        * (colorant) information assume yes, otherwise require the
-       * 'ENDPOINTS_MATCHE_sRGB' colorspace flag to have been set.  If the
+       * 'ENDPOINTS_MATCHP_sRGB' colorspace flag to have been set.  If the
        * colorspace has been determined to be invalid ignore it.
        */
       if ((format & PNG_FORMAT_FLAG_COLOR) != 0 && ((png_ptr->colorspace.flags
@@ -1482,17 +1481,24 @@ png_image_skip_unused_chunks(png_structrp png_ptr)
     *
     * Or image data handling:
     *
-    *    tRNS, bKGD, gAMA, cHRM, sRGB, iCCP and sBIT.
+    *    tRNS, bKGD, gAMA, cHRM, sRGB, [iCCP] and sBIT.
     *
     * This provides a small performance improvement and eliminates any
     * potential vulnerability to security problems in the unused chunks.
+    *
+    * At present the iCCP chunk data isn't used, so iCCP chunk can be ignored
+    * too.  This allows the simplified API to be compiled without iCCP support,
+    * however if the support is there the chunk is still checked to detect
+    * errors (which are unfortunately quite common.)
     */
    {
          static PNG_CONST png_byte chunks_to_process[] = {
             98,  75,  71,  68, '\0',  /* bKGD */
             99,  72,  82,  77, '\0',  /* cHRM */
            103,  65,  77,  65, '\0',  /* gAMA */
+#        ifdef PNG_READ_iCCP_SUPPORTED
            105,  67,  67,  80, '\0',  /* iCCP */
+#        endif
            115,  66,  73,  84, '\0',  /* sBIT */
            115,  82,  71,  66, '\0',  /* sRGB */
            };
@@ -1529,25 +1535,25 @@ set_file_encoding(png_image_read_control *display)
    {
       if (png_gamma_not_sRGB(g))
       {
-         display->file_encoding = E_FILE;
+         display->file_encoding = P_FILE;
          display->gamma_to_linear = png_reciprocal(g);
       }
 
       else
-         display->file_encoding = E_sRGB;
+         display->file_encoding = P_sRGB;
    }
 
    else
-      display->file_encoding = E_LINEAR8;
+      display->file_encoding = P_LINEAR8;
 }
 
 static unsigned int
 decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding)
 {
-   if (encoding == E_FILE) /* double check */
+   if (encoding == P_FILE) /* double check */
       encoding = display->file_encoding;
 
-   if (encoding == E_NOTSET) /* must be the file encoding */
+   if (encoding == P_NOTSET) /* must be the file encoding */
    {
       set_file_encoding(display);
       encoding = display->file_encoding;
@@ -1555,18 +1561,18 @@ decode_gamma(png_image_read_control *display, png_uint_32 value, int encoding)
 
    switch (encoding)
    {
-      case E_FILE:
+      case P_FILE:
          value = png_gamma_16bit_correct(value*257, display->gamma_to_linear);
          break;
 
-      case E_sRGB:
+      case P_sRGB:
          value = png_sRGB_table[value];
          break;
 
-      case E_LINEAR:
+      case P_LINEAR:
          break;
 
-      case E_LINEAR8:
+      case P_LINEAR8:
          value *= 257;
          break;
 
@@ -1585,9 +1591,9 @@ png_colormap_compose(png_image_read_control *display,
    png_uint_32 background, int encoding)
 {
    /* The file value is composed on the background, the background has the given
-    * encoding and so does the result, the file is encoded with E_FILE and the
+    * encoding and so does the result, the file is encoded with P_FILE and the
     * file and alpha are 8-bit values.  The (output) encoding will always be
-    * E_LINEAR or E_sRGB.
+    * P_LINEAR or P_sRGB.
     */
    png_uint_32 f = decode_gamma(display, foreground, foreground_encoding);
    png_uint_32 b = decode_gamma(display, background, encoding);
@@ -1597,7 +1603,7 @@ png_colormap_compose(png_image_read_control *display,
     */
    f = f * alpha + b * (255-alpha);
 
-   if (encoding == E_LINEAR)
+   if (encoding == P_LINEAR)
    {
       /* Scale to 65535; divide by 255, approximately (in fact this is extremely
        * accurate, it divides by 255.00000005937181414556, with no overflow.)
@@ -1607,13 +1613,13 @@ png_colormap_compose(png_image_read_control *display,
       f = (f+32768) >> 16;
    }
 
-   else /* E_sRGB */
+   else /* P_sRGB */
       f = PNG_sRGB_FROM_LINEAR(f);
 
    return f;
 }
 
-/* NOTE: E_LINEAR values to this routine must be 16-bit, but E_FILE values must
+/* NOTE: P_LINEAR values to this routine must be 16-bit, but P_FILE values must
  * be 8-bit.
  */
 static void
@@ -1623,7 +1629,7 @@ png_create_colormap_entry(png_image_read_control *display,
 {
    png_imagep image = display->image;
    const int output_encoding = (image->format & PNG_FORMAT_FLAG_LINEAR) ?
-      E_LINEAR : E_sRGB;
+      P_LINEAR : P_sRGB;
    const int convert_to_Y = (image->format & PNG_FORMAT_FLAG_COLOR) == 0 &&
       (red != green || green != blue);
 
@@ -1633,18 +1639,18 @@ png_create_colormap_entry(png_image_read_control *display,
    /* Update the cache with whether the file gamma is significantly different
     * from sRGB.
     */
-   if (encoding == E_FILE)
+   if (encoding == P_FILE)
    {
-      if (display->file_encoding == E_NOTSET)
+      if (display->file_encoding == P_NOTSET)
          set_file_encoding(display);
 
-      /* Note that the cached value may be E_FILE too, but if it is then the
+      /* Note that the cached value may be P_FILE too, but if it is then the
        * gamma_to_linear member has been set.
        */
       encoding = display->file_encoding;
    }
 
-   if (encoding == E_FILE)
+   if (encoding == P_FILE)
    {
       png_fixed_point g = display->gamma_to_linear;
 
@@ -1652,10 +1658,10 @@ png_create_colormap_entry(png_image_read_control *display,
       green = png_gamma_16bit_correct(green*257, g);
       blue = png_gamma_16bit_correct(blue*257, g);
 
-      if (convert_to_Y || output_encoding == E_LINEAR)
+      if (convert_to_Y || output_encoding == P_LINEAR)
       {
          alpha *= 257;
-         encoding = E_LINEAR;
+         encoding = P_LINEAR;
       }
 
       else
@@ -1663,11 +1669,11 @@ png_create_colormap_entry(png_image_read_control *display,
          red = PNG_sRGB_FROM_LINEAR(red * 255);
          green = PNG_sRGB_FROM_LINEAR(green * 255);
          blue = PNG_sRGB_FROM_LINEAR(blue * 255);
-         encoding = E_sRGB;
+         encoding = P_sRGB;
       }
    }
 
-   else if (encoding == E_LINEAR8)
+   else if (encoding == P_LINEAR8)
    {
       /* This encoding occurs quite frequently in test cases because PngSuite
        * includes a gAMA 1.0 chunk with most images.
@@ -1676,10 +1682,10 @@ png_create_colormap_entry(png_image_read_control *display,
       green *= 257;
       blue *= 257;
       alpha *= 257;
-      encoding = E_LINEAR;
+      encoding = P_LINEAR;
    }
 
-   else if (encoding == E_sRGB && (convert_to_Y || output_encoding == E_LINEAR))
+   else if (encoding == P_sRGB && (convert_to_Y || output_encoding == P_LINEAR))
    {
       /* The values are 8-bit sRGB values, but must be converted to 16-bit
        * linear.
@@ -1688,11 +1694,11 @@ png_create_colormap_entry(png_image_read_control *display,
       green = png_sRGB_table[green];
       blue = png_sRGB_table[blue];
       alpha *= 257;
-      encoding = E_LINEAR;
+      encoding = P_LINEAR;
    }
 
    /* This is set if the color isn't gray but the output is. */
-   if (encoding == E_LINEAR)
+   if (encoding == P_LINEAR)
    {
       if (convert_to_Y)
       {
@@ -1700,7 +1706,7 @@ png_create_colormap_entry(png_image_read_control *display,
          png_uint_32 y = (png_uint_32)6968 * red  + (png_uint_32)23434 * green +
             (png_uint_32)2366 * blue;
 
-         if (output_encoding == E_LINEAR)
+         if (output_encoding == P_LINEAR)
             y = (y + 16384) >> 15;
 
          else
@@ -1709,19 +1715,19 @@ png_create_colormap_entry(png_image_read_control *display,
             y = (y + 128) >> 8;
             y *= 255;
             y = PNG_sRGB_FROM_LINEAR((y + 64) >> 7);
-            encoding = E_sRGB;
+            encoding = P_sRGB;
          }
 
          blue = red = green = y;
       }
 
-      else if (output_encoding == E_sRGB)
+      else if (output_encoding == P_sRGB)
       {
          red = PNG_sRGB_FROM_LINEAR(red * 255);
          green = PNG_sRGB_FROM_LINEAR(green * 255);
          blue = PNG_sRGB_FROM_LINEAR(blue * 255);
          alpha = PNG_DIV257(alpha);
-         encoding = E_sRGB;
+         encoding = P_sRGB;
       }
    }
 
@@ -1730,7 +1736,7 @@ png_create_colormap_entry(png_image_read_control *display,
 
    /* Store the value. */
    {
-#     ifdef PNG_FORMAT_BGR_SUPPORTED
+#     ifdef PNG_FORMAT_AFIRST_SUPPORTED
          const int afirst = (image->format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
             (image->format & PNG_FORMAT_FLAG_ALPHA) != 0;
 #     else
@@ -1742,7 +1748,7 @@ png_create_colormap_entry(png_image_read_control *display,
 #        define bgr 0
 #     endif
 
-      if (output_encoding == E_LINEAR)
+      if (output_encoding == P_LINEAR)
       {
          png_uint_16p entry = png_voidcast(png_uint_16p, display->colormap);
 
@@ -1797,7 +1803,7 @@ png_create_colormap_entry(png_image_read_control *display,
          }
       }
 
-      else /* output encoding is E_sRGB */
+      else /* output encoding is P_sRGB */
       {
          png_bytep entry = png_voidcast(png_bytep, display->colormap);
 
@@ -1839,7 +1845,7 @@ make_gray_file_colormap(png_image_read_control *display)
    unsigned int i;
 
    for (i=0; i<256; ++i)
-      png_create_colormap_entry(display, i, i, i, i, 255, E_FILE);
+      png_create_colormap_entry(display, i, i, i, i, 255, P_FILE);
 
    return i;
 }
@@ -1850,7 +1856,7 @@ make_gray_colormap(png_image_read_control *display)
    unsigned int i;
 
    for (i=0; i<256; ++i)
-      png_create_colormap_entry(display, i, i, i, i, 255, E_sRGB);
+      png_create_colormap_entry(display, i, i, i, i, 255, P_sRGB);
 
    return i;
 }
@@ -1889,13 +1895,13 @@ make_ga_colormap(png_image_read_control *display)
    while (i < 231)
    {
       unsigned int gray = (i * 256 + 115) / 231;
-      png_create_colormap_entry(display, i++, gray, gray, gray, 255, E_sRGB);
+      png_create_colormap_entry(display, i++, gray, gray, gray, 255, P_sRGB);
    }
 
    /* 255 is used here for the component values for consistency with the code
     * that undoes premultiplication in pngwrite.c.
     */
-   png_create_colormap_entry(display, i++, 255, 255, 255, 0, E_sRGB);
+   png_create_colormap_entry(display, i++, 255, 255, 255, 0, P_sRGB);
 
    for (a=1; a<5; ++a)
    {
@@ -1903,7 +1909,7 @@ make_ga_colormap(png_image_read_control *display)
 
       for (g=0; g<6; ++g)
          png_create_colormap_entry(display, i++, g*51, g*51, g*51, a*51,
-            E_sRGB);
+            P_sRGB);
    }
 
    return i;
@@ -1927,7 +1933,7 @@ make_rgb_colormap(png_image_read_control *display)
 
          for (b=0; b<6; ++b)
             png_create_colormap_entry(display, i++, r*51, g*51, b*51, 255,
-               E_sRGB);
+               P_sRGB);
       }
    }
 
@@ -1950,11 +1956,11 @@ png_image_read_colormap(png_voidp argument)
    const png_structrp png_ptr = image->opaque->png_ptr;
    const png_uint_32 output_format = image->format;
    const int output_encoding = (output_format & PNG_FORMAT_FLAG_LINEAR) ?
-      E_LINEAR : E_sRGB;
+      P_LINEAR : P_sRGB;
 
    unsigned int cmap_entries;
    unsigned int output_processing;        /* Output processing option */
-   unsigned int data_encoding = E_NOTSET; /* Encoding libpng must produce */
+   unsigned int data_encoding = P_NOTSET; /* Encoding libpng must produce */
 
    /* Background information; the background color and the index of this color
     * in the color-map if it exists (else 256).
@@ -1974,7 +1980,7 @@ png_image_read_colormap(png_voidp argument)
          png_ptr->num_trans > 0) /* alpha in input */ &&
       ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0) /* no alpha in output */)
    {
-      if (output_encoding == E_LINEAR) /* compose on black */
+      if (output_encoding == P_LINEAR) /* compose on black */
          back_b = back_g = back_r = 0;
 
       else if (display->background == NULL /* no way to remove it */)
@@ -1998,7 +2004,7 @@ png_image_read_colormap(png_voidp argument)
       }
    }
 
-   else if (output_encoding == E_LINEAR)
+   else if (output_encoding == P_LINEAR)
       back_b = back_r = back_g = 65535;
 
    else
@@ -2056,7 +2062,7 @@ png_image_read_colormap(png_voidp argument)
                trans = png_ptr->trans_color.gray;
 
                if ((output_format & PNG_FORMAT_FLAG_ALPHA) == 0)
-                  back_alpha = output_encoding == E_LINEAR ? 65535 : 255;
+                  back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
             }
 
             /* png_create_colormap_entry just takes an RGBA and writes the
@@ -2074,7 +2080,7 @@ png_image_read_colormap(png_voidp argument)
                 */
                if (i != trans)
                   png_create_colormap_entry(display, i, val, val, val, 255,
-                     E_FILE/*8-bit with file gamma*/);
+                     P_FILE/*8-bit with file gamma*/);
 
                /* Else this entry is transparent.  The colors don't matter if
                 * there is an alpha channel (back_alpha == 0), but it does no
@@ -2090,7 +2096,7 @@ png_image_read_colormap(png_voidp argument)
             }
 
             /* We need libpng to preserve the original encoding. */
-            data_encoding = E_FILE;
+            data_encoding = P_FILE;
 
             /* The rows from libpng, while technically gray values, are now also
              * color-map indicies; however, they may need to be expanded to 1
@@ -2119,7 +2125,7 @@ png_image_read_colormap(png_voidp argument)
              * ensuring that the corresponding gray level matches the background
              * color exactly.
              */
-            data_encoding = E_sRGB;
+            data_encoding = P_sRGB;
 
             if (PNG_GRAY_COLORMAP_ENTRIES > image->colormap_entries)
                png_error(png_ptr, "gray[16] color-map: too few entries");
@@ -2143,7 +2149,7 @@ png_image_read_colormap(png_voidp argument)
                      png_color_16 c;
                      png_uint_32 gray = back_g;
 
-                     if (output_encoding == E_LINEAR)
+                     if (output_encoding == P_LINEAR)
                      {
                         gray = PNG_sRGB_FROM_LINEAR(gray * 255);
 
@@ -2151,7 +2157,7 @@ png_image_read_colormap(png_voidp argument)
                          * matches.
                          */
                         png_create_colormap_entry(display, gray, back_g, back_g,
-                           back_g, 65535, E_LINEAR);
+                           back_g, 65535, P_LINEAR);
                      }
 
                      /* The background passed to libpng, however, must be the
@@ -2172,7 +2178,7 @@ png_image_read_colormap(png_voidp argument)
                      break;
                   }
 
-                  back_alpha = output_encoding == E_LINEAR ? 65535 : 255;
+                  back_alpha = output_encoding == P_LINEAR ? 65535 : 255;
                }
 
                /* output_processing means that the libpng-processed row will be
@@ -2209,7 +2215,7 @@ png_image_read_colormap(png_voidp argument)
           * worry about tRNS matching - tRNS is ignored if there is an alpha
           * channel.
           */
-         data_encoding = E_sRGB;
+         data_encoding = P_sRGB;
 
          if (output_format & PNG_FORMAT_FLAG_ALPHA)
          {
@@ -2252,13 +2258,13 @@ png_image_read_colormap(png_voidp argument)
 
                cmap_entries = make_gray_colormap(display);
 
-               if (output_encoding == E_LINEAR)
+               if (output_encoding == P_LINEAR)
                {
                   gray = PNG_sRGB_FROM_LINEAR(gray * 255);
 
                   /* And make sure the corresponding palette entry matches. */
                   png_create_colormap_entry(display, gray, back_g, back_g,
-                     back_g, 65535, E_LINEAR);
+                     back_g, 65535, P_LINEAR);
                }
 
                /* The background passed to libpng, however, must be the sRGB
@@ -2289,7 +2295,7 @@ png_image_read_colormap(png_voidp argument)
                {
                   png_uint_32 gray = (i * 256 + 115) / 231;
                   png_create_colormap_entry(display, i++, gray, gray, gray,
-                     255, E_sRGB);
+                     255, P_sRGB);
                }
 
                /* NOTE: this preserves the full precision of the application
@@ -2297,7 +2303,7 @@ png_image_read_colormap(png_voidp argument)
                 */
                background_index = i;
                png_create_colormap_entry(display, i++, back_r, back_g, back_b,
-                  output_encoding == E_LINEAR ? 65535U : 255U, output_encoding);
+                  output_encoding == P_LINEAR ? 65535U : 255U, output_encoding);
 
                /* For non-opaque input composite on the sRGB background - this
                 * requires inverting the encoding for each component.  The input
@@ -2307,7 +2313,7 @@ png_image_read_colormap(png_voidp argument)
                 * represents.  Consequently 'G' is always sRGB encoded, while
                 * 'A' is linear.  We need the linear background colors.
                 */
-               if (output_encoding == E_sRGB) /* else already linear */
+               if (output_encoding == P_sRGB) /* else already linear */
                {
                   /* This may produce a value not exactly matching the
                    * background, but that's ok because these numbers are only
@@ -2337,7 +2343,7 @@ png_image_read_colormap(png_voidp argument)
                      png_create_colormap_entry(display, i++,
                         PNG_sRGB_FROM_LINEAR(gray + back_rx),
                         PNG_sRGB_FROM_LINEAR(gray + back_gx),
-                        PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, E_sRGB);
+                        PNG_sRGB_FROM_LINEAR(gray + back_bx), 255, P_sRGB);
                   }
                }
 
@@ -2364,7 +2370,7 @@ png_image_read_colormap(png_voidp argument)
              */
             png_set_rgb_to_gray_fixed(png_ptr, PNG_ERROR_ACTION_NONE, -1,
                -1);
-            data_encoding = E_sRGB;
+            data_encoding = P_sRGB;
 
             /* The output will now be one or two 8-bit gray or gray+alpha
              * channels.  The more complex case arises when the input has alpha.
@@ -2409,7 +2415,7 @@ png_image_read_colormap(png_voidp argument)
                   png_gamma_not_sRGB(png_ptr->colorspace.gamma))
                {
                   cmap_entries = make_gray_file_colormap(display);
-                  data_encoding = E_FILE;
+                  data_encoding = P_FILE;
                }
 
                else
@@ -2428,18 +2434,18 @@ png_image_read_colormap(png_voidp argument)
                    * it.  Achieve this simply by ensuring that the entry
                    * selected for the background really is the background color.
                    */
-                  if (data_encoding == E_FILE) /* from the fixup above */
+                  if (data_encoding == P_FILE) /* from the fixup above */
                   {
                      /* The app supplied a gray which is in output_encoding, we
-                      * need to convert it to a value of the input (E_FILE)
+                      * need to convert it to a value of the input (P_FILE)
                       * encoding then set this palette entry to the required
                       * output encoding.
                       */
-                     if (output_encoding == E_sRGB)
-                        gray = png_sRGB_table[gray]; /* now E_LINEAR */
+                     if (output_encoding == P_sRGB)
+                        gray = png_sRGB_table[gray]; /* now P_LINEAR */
 
                      gray = PNG_DIV257(png_gamma_16bit_correct(gray,
-                        png_ptr->colorspace.gamma)); /* now E_FILE */
+                        png_ptr->colorspace.gamma)); /* now P_FILE */
 
                      /* And make sure the corresponding palette entry contains
                       * exactly the required sRGB value.
@@ -2448,14 +2454,14 @@ png_image_read_colormap(png_voidp argument)
                         back_g, 0/*unused*/, output_encoding);
                   }
 
-                  else if (output_encoding == E_LINEAR)
+                  else if (output_encoding == P_LINEAR)
                   {
                      gray = PNG_sRGB_FROM_LINEAR(gray * 255);
 
                      /* And make sure the corresponding palette entry matches.
                       */
                      png_create_colormap_entry(display, gray, back_g, back_g,
-                        back_g, 0/*unused*/, E_LINEAR);
+                        back_g, 0/*unused*/, P_LINEAR);
                   }
 
                   /* The background passed to libpng, however, must be the
@@ -2485,7 +2491,7 @@ png_image_read_colormap(png_voidp argument)
              * to do it once and using PNG_DIV51 on the 6x6x6 reduced RGB cube.
              * Consequently we always want libpng to produce sRGB data.
              */
-            data_encoding = E_sRGB;
+            data_encoding = P_sRGB;
 
             /* Is there any transparency or alpha? */
             if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
@@ -2505,7 +2511,7 @@ png_image_read_colormap(png_voidp argument)
 
                   /* Add a transparent entry. */
                   png_create_colormap_entry(display, cmap_entries, 255, 255,
-                     255, 0, E_sRGB);
+                     255, 0, P_sRGB);
 
                   /* This is stored as the background index for the processing
                    * algorithm.
@@ -2526,7 +2532,7 @@ png_image_read_colormap(png_voidp argument)
                          */
                         for (b=0; b<256; b = (b << 1) | 0x7f)
                            png_create_colormap_entry(display, cmap_entries++,
-                              r, g, b, 128, E_sRGB);
+                              r, g, b, 128, P_sRGB);
                      }
                   }
 
@@ -2555,7 +2561,7 @@ png_image_read_colormap(png_voidp argument)
                   png_create_colormap_entry(display, cmap_entries, back_r,
                         back_g, back_b, 0/*unused*/, output_encoding);
 
-                  if (output_encoding == E_LINEAR)
+                  if (output_encoding == P_LINEAR)
                   {
                      r = PNG_sRGB_FROM_LINEAR(back_r * 255);
                      g = PNG_sRGB_FROM_LINEAR(back_g * 255);
@@ -2595,11 +2601,11 @@ png_image_read_colormap(png_voidp argument)
                             */
                            for (b=0; b<256; b = (b << 1) | 0x7f)
                               png_create_colormap_entry(display, cmap_entries++,
-                                 png_colormap_compose(display, r, E_sRGB, 128,
+                                 png_colormap_compose(display, r, P_sRGB, 128,
                                     back_r, output_encoding),
-                                 png_colormap_compose(display, g, E_sRGB, 128,
+                                 png_colormap_compose(display, g, P_sRGB, 128,
                                     back_g, output_encoding),
-                                 png_colormap_compose(display, b, E_sRGB, 128,
+                                 png_colormap_compose(display, b, P_sRGB, 128,
                                     back_b, output_encoding),
                                  0/*unused*/, output_encoding);
                         }
@@ -2658,7 +2664,7 @@ png_image_read_colormap(png_voidp argument)
                num_trans = 0;
 
             output_processing = PNG_CMAP_NONE;
-            data_encoding = E_FILE; /* Don't change from color-map indicies */
+            data_encoding = P_FILE; /* Don't change from color-map indicies */
             cmap_entries = png_ptr->num_palette;
             if (cmap_entries > 256)
                cmap_entries = 256;
@@ -2680,13 +2686,13 @@ png_image_read_colormap(png_voidp argument)
                       * on the sRGB color in 'back'.
                       */
                      png_create_colormap_entry(display, i,
-                        png_colormap_compose(display, colormap[i].red, E_FILE,
+                        png_colormap_compose(display, colormap[i].red, P_FILE,
                            trans[i], back_r, output_encoding),
-                        png_colormap_compose(display, colormap[i].green, E_FILE,
+                        png_colormap_compose(display, colormap[i].green, P_FILE,
                            trans[i], back_g, output_encoding),
-                        png_colormap_compose(display, colormap[i].blue, E_FILE,
+                        png_colormap_compose(display, colormap[i].blue, P_FILE,
                            trans[i], back_b, output_encoding),
-                        output_encoding == E_LINEAR ? trans[i] * 257U :
+                        output_encoding == P_LINEAR ? trans[i] * 257U :
                            trans[i],
                         output_encoding);
                   }
@@ -2695,7 +2701,7 @@ png_image_read_colormap(png_voidp argument)
                else
                   png_create_colormap_entry(display, i, colormap[i].red,
                      colormap[i].green, colormap[i].blue,
-                     i < num_trans ? trans[i] : 255U, E_FILE/*8-bit*/);
+                     i < num_trans ? trans[i] : 255U, P_FILE/*8-bit*/);
             }
 
             /* The PNG data may have indicies packed in fewer than 8 bits, it
@@ -2723,12 +2729,12 @@ png_image_read_colormap(png_voidp argument)
          png_error(png_ptr, "bad data option (internal error)");
          break;
 
-      case E_sRGB:
+      case P_sRGB:
          /* Change to 8-bit sRGB */
          png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, PNG_GAMMA_sRGB);
          /* FALL THROUGH */
 
-      case E_FILE:
+      case P_FILE:
          if (png_ptr->bit_depth > 8)
             png_set_scale_16(png_ptr);
          break;
@@ -2805,7 +2811,6 @@ png_image_read_and_map(png_voidp argument)
          break;
 
       default:
-         passes = 0;
          png_error(png_ptr, "unknown interlace type");
    }
 
@@ -3124,7 +3129,6 @@ png_image_read_composite(png_voidp argument)
          break;
 
       default:
-         passes = 0;
          png_error(png_ptr, "unknown interlace type");
    }
 
@@ -3273,11 +3277,15 @@ png_image_read_background(png_voidp argument)
          break;
 
       default:
-         passes = 0;
          png_error(png_ptr, "unknown interlace type");
    }
 
-   switch (png_get_bit_depth(png_ptr, info_ptr))
+   /* Use direct access to info_ptr here because otherwise the simplified API
+    * would require PNG_EASY_ACCESS_SUPPORTED (just for this.)  Note this is
+    * checking the value after libpng expansions, not the original value in the
+    * PNG.
+    */
+   switch (info_ptr->bit_depth)
    {
       default:
          png_error(png_ptr, "unexpected bit depth");
@@ -3425,8 +3433,10 @@ png_image_read_background(png_voidp argument)
             unsigned int outchannels = 1+preserve_alpha;
             int swap_alpha = 0;
 
-            if (preserve_alpha && (image->format & PNG_FORMAT_FLAG_AFIRST))
-               swap_alpha = 1;
+#           ifdef PNG_SIMPLIFIED_READ_AFIRST_SUPPORTED
+               if (preserve_alpha && (image->format & PNG_FORMAT_FLAG_AFIRST))
+                  swap_alpha = 1;
+#           endif
 
             for (pass = 0; pass < passes; ++pass)
             {

pngrtran.c

@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.6.4 [September 12, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1942,6 +1942,9 @@ png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
 
          info_ptr->bit_depth = 8;
          info_ptr->num_trans = 0;
+
+         if (png_ptr->palette == NULL)
+            png_error (png_ptr, "Palette is NULL in indexed image");
       }
       else
       {

pngrutil.c

@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.6.4 [September 12, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -278,6 +278,10 @@ png_crc_error(png_structrp png_ptr)
       return (0);
 }
 
+#if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\
+    defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\
+    defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\
+    defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED)
 /* Manage the read buffer; this simply reallocates the buffer if it is not small
  * enough (or if it is not allocated).  The routine returns a pointer to the
  * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
@@ -325,6 +329,7 @@ png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
 
    return buffer;
 }
+#endif /* PNG_READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */
 
 /* png_inflate_claim: claim the zstream for some nefarious purpose that involves
  * decompression.  Returns Z_OK on success, else a zlib error code.  It checks
@@ -2764,6 +2769,7 @@ 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
@@ -2775,15 +2781,16 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
     * This is just an optimization to avoid multiple calls to the lookup
     * function.
     */
-#  ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
+#  ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#     ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+         keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
+#     endif
 #  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.
@@ -2891,7 +2898,7 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
 
          png_crc_finish(png_ptr, length);
       }
-#  endif /* PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED */
+#  endif
 
 #  ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
       /* Now store the chunk in the chunk list if appropriate, and if the limits
@@ -2930,9 +2937,8 @@ png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
          }
 #     endif
       }
-#  else /* no store support! */
+#  else /* no store support: the chunk must be handled by the user callback */
       PNG_UNUSED(info_ptr)
-#     error untested code (reading unknown chunks with no store support)
 #  endif
 
    /* Regardless of the error handling below the cached data (if any) can be
@@ -3870,7 +3876,6 @@ png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
       if (pb < pa) pa = pb, a = b;
       if (pc < pa) a = c;
 
-      c = b;
       a += *row;
       *row++ = (png_byte)a;
    }

pngset.c

@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.6.3 [July 18, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -527,7 +527,7 @@ png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
 #        endif
       ))
    {
-      png_chunk_report(png_ptr, "Invalid palette", PNG_CHUNK_ERROR);
+      png_error(png_ptr, "Invalid palette");
       return;
    }
 

pngtest.c

@@ -1,7 +1,7 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.6.2 [April 25, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -573,7 +573,8 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
             /* We must free the list element too, but first kill
                the memory that is to be freed. */
             memset(ptr, 0x55, pinfo->size);
-            png_free_default(png_ptr, pinfo);
+            if (pinfo)
+               free(pinfo);
             pinfo = NULL;
             break;
          }
@@ -592,7 +593,8 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
    if (verbose)
       printf("Freeing %p\n", ptr);
 
-   png_free_default(png_ptr, ptr);
+   if (ptr)
+      free(ptr);
    ptr = NULL;
 }
 #endif /* PNG_USER_MEM_SUPPORTED && PNG_DEBUG */
@@ -1391,11 +1393,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 
-#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
-   png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
-#endif
-#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
-   png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
+#  ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+      png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
+#  endif
+#  ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+      png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#  endif
 #endif
 
    pngtest_debug("Reading and writing end_info data");
@@ -1576,14 +1580,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 
 #ifdef PNG_WRITE_SUPPORTED /* else nothing was written */
    {
-      int wrote_question = 0;
-
       for (;;)
       {
+         static int wrote_question = 0;
          png_size_t num_in, num_out;
          char inbuf[256], outbuf[256];
 
-
          num_in = fread(inbuf, 1, sizeof inbuf, fpin);
          num_out = fread(outbuf, 1, sizeof outbuf, fpout);
 
@@ -1968,4 +1970,4 @@ main(void)
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_4 Your_png_h_is_not_version_1_6_4;
+typedef png_libpng_version_1_6_8 Your_png_h_is_not_version_1_6_8;

pngwio.c

@@ -1,7 +1,7 @@
 
 /* pngwio.c - functions for data output
  *
- * Last changed in libpng 1.6.0 [February 14, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -149,6 +149,8 @@ png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
 #  else
    png_ptr->output_flush_fn = output_flush_fn;
 #  endif
+#else
+   PNG_UNUSED(output_flush_fn)
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
 
    /* It is an error to read while writing a png file */

pngwrite.c

@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.6.2 [April 25, 2013]
+ * Last changed in libpng 1.6.8 [December 19, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1638,14 +1638,16 @@ png_write_image_16bit(png_voidp argument)
 
    if (image->format & PNG_FORMAT_FLAG_ALPHA)
    {
-      if (image->format & PNG_FORMAT_FLAG_AFIRST)
-      {
-         aindex = -1;
-         ++input_row; /* To point to the first component */
-         ++output_row;
-      }
+#     ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+         if (image->format & PNG_FORMAT_FLAG_AFIRST)
+         {
+            aindex = -1;
+            ++input_row; /* To point to the first component */
+            ++output_row;
+         }
 
-      else
+         else
+#     endif
          aindex = channels;
    }
 
@@ -1794,14 +1796,16 @@ png_write_image_8bit(png_voidp argument)
       png_bytep row_end;
       int aindex;
 
-      if (image->format & PNG_FORMAT_FLAG_AFIRST)
-      {
-         aindex = -1;
-         ++input_row; /* To point to the first component */
-         ++output_row;
-      }
+#     ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED
+         if (image->format & PNG_FORMAT_FLAG_AFIRST)
+         {
+            aindex = -1;
+            ++input_row; /* To point to the first component */
+            ++output_row;
+         }
 
-      else
+         else
+#     endif
          aindex = channels;
 
       /* Use row_end in place of a loop counter: */
@@ -1881,7 +1885,8 @@ png_image_set_PLTE(png_image_write_control *display)
    const png_uint_32 format = image->format;
    const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format);
 
-#  ifdef PNG_FORMAT_BGR_SUPPORTED
+#  if defined(PNG_FORMAT_BGR_SUPPORTED) &&\
+      defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED)
       const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 &&
          (format & PNG_FORMAT_FLAG_ALPHA) != 0;
 #  else

projects/vstudio/readme.txt

@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.4 - September 12, 2013
+libpng version 1.6.8 - December 19, 2013
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 

projects/vstudio/zlib.props

@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.4 - September 12, 2013
+ * libpng version 1.6.8 - December 19, 2013
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *

scripts/README.txt

@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.6.4 - September 12, 2013
+Makefiles for  libpng version 1.6.8 - December 19, 2013
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.4)
+                       (gcc, creates libpng16.so.16.1.6.8)
  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 libpng16.so.16.1.6.4)
+                       (gcc, creates libpng16.so.16.1.6.8)
  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 libpng16.so.16.1.6.4)
+                       creates libpng16.so.16.1.6.8)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng16.so.16.1.6.4)
+                       creates libpng16.so.16.1.6.8)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng16.so.16.1.6.4)
+                       creates libpng16.so.16.1.6.8)
  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 1.6.4"
+PNG_DFN ";Version 1.6.8"
 
 #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=1.6.4
+version=1.6.8
 prefix=""
 libdir=""
 libs=""

scripts/libpng.pc.in

@@ -5,6 +5,6 @@ includedir=@includedir@/libpng16
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.6.4
+Version: 1.6.8
 Libs: -L${libdir} -lpng16
 Cflags: -I${includedir}

scripts/makefile.cegcc

@@ -23,7 +23,7 @@
 
 VERMAJ = 1
 VERMIN = 6
-VERMIC = 4
+VERMIC = 8
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)

scripts/makefile.linux

@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 4
+RELEASE = 8
 
 # Shared library names:
 LIBSO=$(LIBNAME).so

scripts/makefile.msys

@@ -18,7 +18,7 @@ exec_prefix=$(prefix)
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 4
+RELEASE = 8
 
 # Shared library names:
 LIBSO=$(LIBNAME).dll

scripts/makefile.ne12bsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include/libpng16
 
 LIB=	png16
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.6.4
+SHLIB_MINOR=	1.6.8
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c

scripts/makefile.netbsd

@@ -17,7 +17,7 @@ INCSDIR=${LOCALBASE}/include
 
 LIB=	png
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.4
+SHLIB_MINOR=	1.6.8
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c

scripts/makefile.openbsd

@@ -11,7 +11,7 @@ LIBDIR=	${PREFIX}/lib
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.4
+SHLIB_MINOR=	1.6.8
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \

scripts/options.awk

@@ -282,7 +282,7 @@ $1 == "option" && NF >= 2{
       for (i=istart; i<=NF; ++i) {
          val=$(i)
          sub(/,$/,"",val)
-         if (val == "on" || val == "off" || val == "disabled") {
+         if (val == "on" || val == "off" || val == "disabled" || val =="enabled") {
             key = ""
             if (onoff != val) {
                # on or off can zap disabled or enabled:
@@ -687,9 +687,11 @@ END{
          }
 
          # if
+         have_ifs = 0
          nreqs = split(iffs[i], r)
          print "#undef PNG_no_if" >out
          if (nreqs > 0) {
+            have_ifs = 1
             print "/* if" iffs[i], "*/" >out
             print "#define PNG_no_if 1" >out
             for (j=1; j<=nreqs; ++j) {
@@ -727,7 +729,10 @@ END{
 
          print "#   ifndef PNG_" i "_SUPPORTED /*!command line*/" >out
          print "#    ifdef PNG_not_enabled /*!enabled*/" >out
-         if (option[i] == "off" || option[i] == "disabled" && everything != "on" || option[i] == "enabled" && everything == "off") {
+         # 'have_ifs' here means that everything = "off" still allows an 'if' on
+         # an otherwise enabled option to turn it on; otherwise the 'if'
+         # handling is effectively disabled by 'everything = off'
+         if (option[i] == "off" || option[i] == "disabled" && everything != "on" || option[i] == "enabled" && everything == "off" && !have_ifs) {
             print "#      undef PNG_on /*default off*/" >out
          } else {
             print "#      ifdef PNG_NO_" i >out

scripts/pnglibconf.dfa

@@ -294,12 +294,16 @@ option BENIGN_READ_ERRORS requires BENIGN_ERRORS
 option MNG_FEATURES
 
 # Arithmetic options, the first is the big switch that chooses between internal
-# floating and fixed point arithmetic implementations - it does not affect any
+# floating and fixed point arithmetic implementations - it does not affect an
 # APIs.  The second two (the _POINT settings) switch off individual APIs.
+#
+# Prior to libpng 1.6.8 one of the API (_POINT) variants had to be selected.  At
+# 1.6.8 this restriction has been removed; the simplified API can be used
+# without enabling any of the low level fixed/floating APIs.
 
 option FLOATING_ARITHMETIC
-option FLOATING_POINT enables ok_math
-option FIXED_POINT enables ok_math
+option FLOATING_POINT
+option FIXED_POINT
 
 # The following is always on (defined empty)
 
@@ -435,7 +439,7 @@ option READ_TRANSFORMS requires READ
 # If you handle gamma issues outside libpng then you do not need the libpng
 # gamma processing; and it is an enormous waste of space.  You just need to
 # remove the use of libpng APIs that depend on it.
-option READ_GAMMA requires READ_TRANSFORMS, READ_gAMA
+option READ_GAMMA requires READ_TRANSFORMS, READ_gAMA, READ_sRGB
 
 option READ_ALPHA_MODE requires READ_TRANSFORMS, READ_GAMMA
 option READ_BACKGROUND requires READ_TRANSFORMS, READ_STRIP_ALPHA, READ_GAMMA
@@ -448,7 +452,7 @@ option READ_INVERT_ALPHA requires READ_TRANSFORMS
 option READ_INVERT requires READ_TRANSFORMS
 option READ_PACK requires READ_TRANSFORMS
 option READ_PACKSWAP requires READ_TRANSFORMS
-option READ_RGB_TO_GRAY requires READ_TRANSFORMS, READ_GAMMA
+option READ_RGB_TO_GRAY requires READ_TRANSFORMS, READ_GAMMA enables COLORSPACE
 option READ_SCALE_16_TO_8 requires READ_TRANSFORMS
 option READ_SHIFT requires READ_TRANSFORMS
 option READ_STRIP_16_TO_8 requires READ_TRANSFORMS
@@ -753,6 +757,13 @@ option SAVE_UNKNOWN_CHUNKS enables READ_UNKNOWN_CHUNKS, STORE_UNKNOWN_CHUNKS
 # chunks, the callback can either handle the chunk entirely itself or request
 # that libpng store the chunk for later retrieval via png_get_unknown_chunks.
 #
+# NOTE: If STORE_UNKNOWN_CHUNKS is not enabled (which is the default if
+# both SAVE_UNKNOWN_CHUNKS and WRITE_UNKNOWN_CHUNKS are disabled) then a
+# 0 result from the callback will be ignored because no support for saving
+# unknown chunks has been compiled in.  The normal symptom is that your app
+# fails to compile because png_get_unknown_chunks is no longer defined in png.h.
+# If you encounter this issue simply enable STORE_UNKNOWN_CHUNKS in your build.
+#
 # Note that there is no 'WRITE_USER_CHUNKS' so the USER_CHUNKS option is always
 # the same as READ_USER_CHUNKS at present
 option READ_USER_CHUNKS requires READ, UNKNOWN_CHUNKS
@@ -798,13 +809,13 @@ option SAVE_INT_32 disabled
 option WRITE_OPTIMIZE_CMF requires WRITE
 
 option READ_COMPRESSED_TEXT disabled
-option READ_iCCP enables READ_COMPRESSED_TEXT
 option READ_iTXt enables READ_COMPRESSED_TEXT
 option READ_zTXt enables READ_COMPRESSED_TEXT
 option READ_COMPRESSED_TEXT enables READ_TEXT
 
 option WRITE_oFFs enables SAVE_INT_32
 option WRITE_pCAL enables SAVE_INT_32
+option WRITE_cHRM enables SAVE_INT_32
 
 option WRITE_COMPRESSED_TEXT disabled
 option WRITE_iCCP enables WRITE_COMPRESSED_TEXT
@@ -832,30 +843,44 @@ option READ_GET_PALETTE_MAX requires READ_CHECK_FOR_INVALID_INDEX disabled
 option WRITE_GET_PALETTE_MAX requires WRITE_CHECK_FOR_INVALID_INDEX disabled
 
 # Simplified API options (added at libpng-1.6.0)
+#  In libpng 1.6.8 the handling of these options was changed to used 'requires'
+#  throughout, so that disabling some of the low level support always disables
+#  the base simplified read/write API.  This much simplifies the handling and
+#  makes 'everything = off' work in a more intuitive way.  It eliminates a
+#  previously reported feature that APIs previously enabled by the simplified
+#  API couldn't be turned off without explicitly turning off the simplified
+#  APIs.
+#
 # Read:
 option SIMPLIFIED_READ,
-   requires SEQUENTIAL_READ READ_TRANSFORMS, SETJMP, BENIGN_ERRORS READ_GAMMA,
-   enables READ_EXPAND, READ_16BIT READ_EXPAND_16, READ_SCALE_16_TO_8,
-      READ_RGB_TO_GRAY, READ_ALPHA_MODE READ_BACKGROUND READ_STRIP_ALPHA,
-      READ_FILLER, READ_SWAP
+   requires SEQUENTIAL_READ, READ_TRANSFORMS, SETJMP, BENIGN_ERRORS,
+      READ_EXPAND, READ_16BIT, READ_EXPAND_16, READ_SCALE_16_TO_8,
+      READ_RGB_TO_GRAY, READ_ALPHA_MODE, READ_BACKGROUND, READ_STRIP_ALPHA,
+      READ_FILLER, READ_SWAP, READ_PACK, READ_GRAY_TO_RGB, READ_GAMMA,
+      READ_tRNS, READ_bKGD, READ_gAMA, READ_cHRM, READ_sRGB, READ_sBIT
 
-option SIMPLIFIED_READ_AFIRST requires SIMPLIFIED_READ disabled
-option READ_SWAP_ALPHA enables SIMPLIFIED_READ_AFIRST
+# AFIRST and BGR read options:
+#  Prior to libpng 1.6.8 these were disabled but switched on if the low level
+#  libpng routines that do the swaps were enabled.  This worked but was
+#  confusing.  In libpng 1.6.8 the options were changed to simple 'requires'
+#  and are enabled by default.  This should work the same way in practice.
+option SIMPLIFIED_READ_AFIRST enables FORMAT_AFIRST,
+   requires SIMPLIFIED_READ READ_SWAP_ALPHA
 
-option SIMPLIFIED_READ_BGR requires SIMPLIFIED_READ disabled
-option READ_BGR enables SIMPLIFIED_READ_BGR
+option SIMPLIFIED_READ_BGR enables FORMAT_BGR,
+   requires SIMPLIFIED_READ READ_BGR
 
 # Write:
 option SIMPLIFIED_WRITE,
-   requires WRITE STDIO, SETJMP,
-   enables WRITE_SWAP WRITE_gAMA, WRITE_sRGB WRITE_cHRM
+   requires WRITE STDIO, SETJMP, WRITE_SWAP, WRITE_PACK,
+      WRITE_tRNS, WRITE_gAMA, WRITE_sRGB, WRITE_cHRM
 
-option SIMPLIFIED_WRITE_AFIRST requires SIMPLIFIED_WRITE disabled
-option WRITE_SWAP_ALPHA enables SIMPLIFIED_WRITE_AFIRST
+option SIMPLIFIED_WRITE_AFIRST enables FORMAT_AFIRST,
+   requires SIMPLIFIED_WRITE WRITE_SWAP_ALPHA
 
-option SIMPLIFIED_WRITE_BGR requires SIMPLIFIED_WRITE disabled
-option WRITE_BGR enables SIMPLIFIED_WRITE_BGR
+option SIMPLIFIED_WRITE_BGR enables FORMAT_BGR,
+   requires SIMPLIFIED_WRITE WRITE_BGR
 
 # Formats:
-option FORMAT_AFIRST if SIMPLIFIED_READ_AFIRST, SIMPLIFIED_WRITE_AFIRST
-option FORMAT_BGR if SIMPLIFIED_READ_BGR, SIMPLIFIED_WRITE_BGR
+option FORMAT_AFIRST disabled
+option FORMAT_BGR disabled

scripts/pnglibconf.h.prebuilt

@@ -1,8 +1,8 @@
-/* libpng 1.6.4 STANDARD API DEFINITION */
+/* libpng 1.6.8 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.4 - September 12, 2013 */
+/* Libpng version 1.6.8 - December 19, 2013 */
 
 /* Copyright (c) 1998-2013 Glenn Randers-Pehrson */
 

scripts/symbols.def

@@ -1,4 +1,4 @@
-;Version 1.6.4
+;Version 1.6.8
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng