- updated to 1.2.51:
Ignore, with a warning, out-of-range value of num_trans in png_set_tRNS().
Replaced AM_CONFIG_HEADER(config.h) with
AC_CONFIG_HEADERS([config.h]) in configure.ac
Changed default value of PNG_USER_CACHE_MAX from 0 to 32767 in pngconf.h.
Avoid a possible memory leak in contrib/gregbook/readpng.c
Revised libpng.3 so that "doclifter" can process it.
Changed '"%s"m' to '"%s" m' in png_debug macros to improve portability
among compilers.
Rebuilt the configure scripts with autoconf-2.69 and automake-1.14.1
Removed potentially misleading warning from png_check_IHDR().
Quiet set-but-not-used warnings in pngset.c
Quiet an uninitialized memory warning from VC2013 in png_get_png().
Quiet unused variable warnings from clang by porting PNG_UNUSED() from
libpng-1.4.6.
Added -DZ_SOLO to CFLAGS in contrib/pngminim/*/makefile
Added an #ifdef PNG_FIXED_POINT_SUPPORTED/#endif in pngset.c