mirror of
https://git.code.sf.net/p/libpng/code.git
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269b753496
This removes the default build of an undocumented feature to disable Adler32 checksums on those systems where it was the default. The PR is motived by github #187 however it fixes a much more general problem (#187 is limited to an issue where libpng "crashes" on some manufacturer systems). The fix is based on a suggestion by @sgowdev who is the originator of the issue. When libpng disables the checking of Adler32 checksums it does so by an undocumented and therefore possibly unsupported call to a zlib function which does not exist in some versions of zlib. Fortunately libpng only does this if the caller of libpng explicitly asks for it to happen. Unfortunately the call to the undocumented function is still in the compiled and built libpng and this means that on some systems (as identified in #187) libpng can fail to load or maybe even crash. The libpng authors are currently unaware of any program or system that uses this feature and none has been identified by the contributors to In this fix an option is added to *enable* the code so that by default the code is *disabled* - this is a simple generalization of the suggestion by @sgowdev. BENEFITS: the problem is eliminated, users of the functionality, if any, are idenfified, the functionality can be implemented correctly in the future or it can be removed. Hardly anyone complains. COSTS: someone will complain that they have to enable an option in a libpng build to use a feature that never worked consistently in the first place. This patch has been tested both with the option enabled and with it disabled via pngusr.dfa. Tests, checks pass with cmake and configure, make distcheck passes on configure. Reported-by: Stephen Gowen <dev.sgowen@gmail.com> Signed-off-by: John Bowler <jbowler@acm.org> Signed-off-by: Cosmin Truta <ctruta@gmail.com>
Makefiles for libpng
pnglibconf.h.prebuilt => Configuration settings
makefile.linux => Linux/ELF makefile
(gcc, creates shared libpng16.so.16.1.6.*)
makefile.linux-opt=> Linux/ELF makefile with hardware optimizations on
(gcc, creates shared libpng16.so.16.1.6.*)
makefile.gcc => Generic makefile (gcc, creates static libpng.a)
makefile.acorn => Acorn makefile
makefile.aix => AIX/gcc makefile
makefile.amiga => Amiga makefile
makefile.atari => Atari makefile
makefile.bc32 => 32-bit Borland C++ (all modules compiled in C mode)
makefile.beos => BeOS makefile
makefile.clang => Generic clang makefile
makefile.darwin => Darwin makefile, for macOS (formerly Mac OS X)
makefile.dec => DEC Alpha UNIX makefile
makefile.dj2 => DJGPP 2 makefile
makefile.freebsd => FreeBSD makefile
makefile.gcc => Generic gcc makefile
makefile.hpgcc => HPUX makefile using gcc
makefile.hpux => HPUX (10.20 and 11.00) makefile
makefile.hp64 => HPUX (10.20 and 11.00) makefile, 64-bit
makefile.ibmc => IBM C/C++ version 3.x for Win32 and OS/2 (static)
makefile.intel => Intel C/C++ version 4.0 and later
makefile.mips => MIPS makefile
makefile.netbsd => NetBSD/cc makefile, makes shared libpng.so
makefile.openbsd => OpenBSD makefile
makefile.sco => SCO OSr5 ELF and Unixware 7 with Native cc
makefile.sggcc => Silicon Graphics makefile
(gcc, creates shared libpng16.so.16.1.6.*)
makefile.sgi => Silicon Graphics IRIX makefile (cc, creates static lib)
makefile.solaris => Solaris 2.X makefile
(gcc, creates shared libpng16.so.16.1.6.*)
makefile.so9 => Solaris 9 makefile
(gcc, creates shared libpng16.so.16.1.6.*)
makefile.std => Generic UNIX makefile (cc, creates static libpng.a)
makefile.sunos => Sun makefile
makefile.32sunu => Sun Ultra 32-bit makefile
makefile.64sunu => Sun Ultra 64-bit makefile
makefile.vcwin32 => makefile for Microsoft Visual C++ 4.0 and later
makevms.com => VMS build script
smakefile.ppc => AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
(Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
Other supporting scripts:
README.txt => This file
descrip.mms => VMS makefile for MMS or MMK
libpng-config-body.in => used by several makefiles to create libpng-config
libpng-config-head.in => used by several makefiles to create libpng-config
libpng.pc.in => Used by several makefiles to create libpng.pc
pngwin.rc => Used by the visualc71 project
pngwin.def => Used by makefile.os2
pngwin.dfn => Used to maintain pngwin.def
SCOPTIONS.ppc => Used with smakefile.ppc
checksym.awk => Used for maintaining pnglibconf.h
def.dfn => Used for maintaining pnglibconf.h
options.awk => Used for maintaining pnglibconf.h
pnglibconf.dfa => Used for maintaining pnglibconf.h
pnglibconf.mak => Used for maintaining pnglibconf.h
sym.dfn => Used for symbol versioning
symbols.def => Used for symbol versioning
symbols.dfn => Used for symbol versioning
vers.dfn => Used for symbol versioning
libtool.m4 => Used by autoconf tools
ltoptions.m4 => Used by autoconf tools
ltsugar.m4 => Used by autoconf tools
ltversion.m4 => Used by autoconf tools
lt~obsolete.m4 => Used by autoconf tools
intprefix.dfn => Used by autoconf tools
macro.lst => Used by autoconf tools
prefix.dfn => Used by autoconf tools
Further information can be found in comments in the individual scripts and
makefiles.