[libpng16] Imported from libpng-1.6.8rc02.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 1.5.18beta01 - August 21, 2013
+Libpng 1.6.8rc02 - December 14, 2013
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -9,26 +9,56 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.5.18beta01.tar.xz (LZMA-compressed, recommended)
-   1.5.18beta01.tar.gz
-   1.5.18beta01.tar.bz2
+   1.6.8rc02.tar.xz (LZMA-compressed, recommended)
+   1.6.8rc02.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp1518b01.7z  (LZMA-compressed, recommended)
-   lp1518b01.zip
+   lp168r02.7z  (LZMA-compressed, recommended)
+   lp168r02.zip
 
 Other information:
 
-   1.5.18beta01-README.txt
-   1.5.18beta01-LICENSE.txt
+   1.6.8rc02-README.txt
+   1.6.8rc02-LICENSE.txt
+   Gnupg/*.asc (PGP armored detached signatures)
 
-Changes since the last public release (1.5.17):
+Changes since the last public release (1.6.7):
 
-Version 1.5.18beta01 [August 21, 2013]
-  Delay calling png_init_filter_functions() until a row with nonzero filter
-    is found.
+Version 1.6.8beta01 [November 24, 2013]
+  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().
+
+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().
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CMakeLists.txt

@@ -15,8 +15,8 @@ project(libpng C)
 enable_testing()
 
 set(PNGLIB_MAJOR 1)
-set(PNGLIB_MINOR 5)
-set(PNGLIB_RELEASE 18)
+set(PNGLIB_MINOR 6)
+set(PNGLIB_RELEASE 8)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
@@ -104,10 +104,11 @@ set(pngtest_sources
 set(pngvalid_sources
   contrib/libtests/pngvalid.c
 )
+set(pngstest_sources
+  contrib/libtests/pngstest.c
+)
 # SOME NEEDED DEFINITIONS
 
-add_definitions(-DPNG_CONFIGURE_LIBPNG)
-
 if(MSVC)
   add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
 endif(MSVC)
@@ -163,6 +164,40 @@ if(PNG_TESTS AND PNG_SHARED)
   add_executable(pngvalid ${pngvalid_sources})
   target_link_libraries(pngvalid ${PNG_LIB_NAME})
   add_test(pngvalid ./pngvalid)
+  add_executable(pngstest ${pngstest_sources})
+  target_link_libraries(pngstest ${PNG_LIB_NAME})
+  add_test(pngstest ./pngstest
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g01.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g02.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g04.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn2c08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn2c16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn3p01.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn3p02.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn3p04.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn4a08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn4a16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn6a08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn6a16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g01.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g02.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g04.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn2c16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbgn2c16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbgn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbrn2c08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbwn0g16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbwn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbyn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n0g08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n2c08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp1n3p08.png
+  )
 endif()
 
 # Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set
@@ -199,7 +234,7 @@ endif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
 # we use the same files like ./configure, so we have to set its vars
 # Only do this on Windows for Cygwin - the files don't make much sense outside
 # a UNIX look alike
-if(NOT WIN32 OR CYGWIN OR MINGW) 
+if(NOT WIN32 OR CYGWIN OR MINGW)
   set(prefix      ${CMAKE_INSTALL_PREFIX})
   set(exec_prefix ${CMAKE_INSTALL_PREFIX})
   set(libdir      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
@@ -217,9 +252,9 @@ endif(NOT WIN32 OR CYGWIN OR MINGW)
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 15.${PNGLIB_RELEASE}.1.5.18beta01
-    VERSION 15.${PNGLIB_RELEASE}.0
-    SOVERSION 15
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.8rc02
+    VERSION 16.${PNGLIB_RELEASE}.0
+    SOVERSION 16
     CLEAN_DIRECT_OUTPUT 1)
 endif()
 if(PNG_STATIC)
@@ -251,7 +286,7 @@ if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
       ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
   if(PNG_SHARED)
-    # Create a symlink for libpng.dll.a => libpng15.dll.a on Cygwin
+    # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
     if(CYGWIN OR MINGW)
        get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE})
        CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})

LICENSE

@@ -10,7 +10,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.5.18beta01, August 21, 2013, are
+libpng versions 1.2.6, August 15, 2004, through 1.6.8rc02, December 14, 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
-August 21, 2013
+December 14, 2013

Makefile.am

@@ -4,25 +4,65 @@
 
 PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 
-# libpng does not follow GNU file name conventions
-
-# "color-tests" requires automake 1.11.1 or later.  Enable it if you like,
-# to get red "FAIL" and green "PASS" notations during tests.
-# AUTOMAKE_OPTIONS = foreign color-tests
-AUTOMAKE_OPTIONS = foreign
+ACLOCAL_AMFLAGS = -I scripts
 
 # test programs - run on make check, make distcheck
-TESTS_ENVIRONMENT= srcdir=$(srcdir)
-check_PROGRAMS= pngtest
+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
-TESTS = test-pngtest.sh
 
-# Only do the following if the contrib directory is present.
-check_PROGRAMS+= pngvalid
 pngvalid_SOURCES = contrib/libtests/pngvalid.c
 pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-TESTS += test-pngvalid-simple.sh test-pngvalid-full.sh
+
+pngstest_SOURCES = contrib/libtests/pngstest.c
+pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngunknown_SOURCES = contrib/libtests/pngunknown.c
+pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngfix_SOURCES = contrib/tools/pngfix.c
+pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
+
+# Generally these are single line shell scripts to run a test with a particular
+# set of parameters:
+TESTS =\
+   tests/pngtest\
+   tests/pngvalid-gamma-16-to-8 tests/pngvalid-gamma-alpha-mode\
+   tests/pngvalid-gamma-background tests/pngvalid-gamma-expand16-alpha-mode\
+   tests/pngvalid-gamma-expand16-background\
+   tests/pngvalid-gamma-expand16-transform tests/pngvalid-gamma-sbit\
+   tests/pngvalid-gamma-threshold tests/pngvalid-gamma-transform\
+   tests/pngvalid-progressive-interlace-size\
+   tests/pngvalid-progressive-interlace-standard\
+   tests/pngvalid-progressive-interlace-transform\
+   tests/pngvalid-progressive-standard tests/pngvalid-standard\
+   tests/pngstest-0g01 tests/pngstest-0g02 tests/pngstest-0g04\
+   tests/pngstest-0g08 tests/pngstest-0g16 tests/pngstest-2c08\
+   tests/pngstest-2c16 tests/pngstest-3p01 tests/pngstest-3p02\
+   tests/pngstest-3p04 tests/pngstest-3p08 tests/pngstest-4a08\
+   tests/pngstest-4a16 tests/pngstest-6a08 tests/pngstest-6a16\
+   tests/pngstest-error tests/pngunknown-IDAT\
+   tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
+   tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg
+
+# These tests are expected, and required, to fail:
+XFAIL_TESTS = tests/pngstest-error
 
 # man pages
 dist_man_MANS= libpng.3 libpngpf.3 png.5
@@ -41,14 +81,12 @@ 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
 
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_CPPFLAGS = @LIBPNG_DEFINES@
-
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \
 	-version-number @PNGLIB_MAJOR@@PNGLIB_MINOR@:@PNGLIB_RELEASE@:0
 
@@ -77,25 +115,32 @@ nodist_pkginclude_HEADERS= pnglibconf.h
 pkgconfigdir = @pkgconfigdir@
 pkgconfig_DATA = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc
 
-#extra source distribution files.
+# Extra source distribution files, '${srcdir}' is used below to stop build files
+# from those directories being included.  This only works if the configure is
+# not done in the source directory!
 EXTRA_DIST= \
 	ANNOUNCE CHANGES INSTALL LICENSE README TODO \
 	pngtest.png pngbar.png pngnow.png pngbar.jpg autogen.sh \
 	${srcdir}/contrib ${srcdir}/projects ${srcdir}/scripts \
-	$(TESTS) \
+	$(TESTS) $(XFAIL_TESTS) tests/pngstest \
 	CMakeLists.txt example.c libpng-manual.txt
 
 SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk scripts/pnglibconf.dfn
 
-CLEANFILES= dfn.c dfn?.out *.out.? scripts/*.out.? pngout.png \
-	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc \
+CLEANFILES= *.tf? pngout.png libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc \
 	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config libpng.vers libpng.sym \
-	check.new pnglibconf.* symbols.new pngtest-log.txt \
+	check.new pnglibconf.* pngprefix.h symbols.new pngtest-log.txt \
 	$(SCRIPT_CLEANFILES)
 
 MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess config.h.in \
 config.sub configure depcomp install-sh ltmain.sh missing
 
+# PNG_COPTS give extra options for the C compiler to be used on all compilation
+# steps (unless targe_CFLAGS is specified; that will take precedence over
+# AM_CFLAGS)
+PNG_COPTS = @PNG_COPTS@
+AM_CFLAGS = ${PNG_COPTS}
+
 # DFNCPP is normally just CPP - the C preprocessor - but on Solaris and maybe
 # other operating systems (NeXT?) the C preprocessor selected by configure
 # checks input tokens for validity - effectively it performs part of the ANSI-C
@@ -112,7 +157,9 @@ $(PNGLIB_BASENAME)-config: libpng-config
 	cp libpng-config $@
 
 scripts/sym.out scripts/vers.out: png.h pngconf.h pnglibconf.h
+scripts/prefix.out: png.h pngconf.h pnglibconf.out
 scripts/symbols.out: png.h pngconf.h $(srcdir)/scripts/pnglibconf.h.prebuilt
+scripts/intprefix.out: pnglibconf.h
 
 libpng.sym: scripts/sym.out
 	rm -f $@
@@ -120,19 +167,58 @@ libpng.sym: scripts/sym.out
 libpng.vers: scripts/vers.out
 	rm -f $@
 	cp $? $@
+
+if DO_PNG_PREFIX
+# Rename functions in scripts/prefix.out with a PNG_PREFIX prefix.
+# Rename macros in scripts/macro.lst from PNG_PREFIXpng_ to PNG_ (the actual
+# implementation of the macro).
+pnglibconf.h: pnglibconf.out scripts/prefix.out scripts/macro.lst
+	rm -f $@
+	$(AWK) 's==0 && NR>1{print prev}\
+	   s==0{prev=$$0}\
+	   s==1{print "#define", $$1, "@PNG_PREFIX@" $$1}\
+	   s==2{print "#define @PNG_PREFIX@png_" $$1, "PNG_" $$1}\
+	   END{print prev}' s=0 pnglibconf.out s=1 scripts/prefix.out\
+	   s=2 ${srcdir}/scripts/macro.lst >pnglibconf.tf8
+	mv pnglibconf.tf8 $@
+
+pngprefix.h: scripts/intprefix.out
+	rm -f pngprefix.tf1
+	$(AWK) '{print "#define", $$1, "@PNG_PREFIX@" $$1}' $? >pngprefix.tf1
+	mv pngprefix.tf1 $@
+else
 pnglibconf.h: pnglibconf.out
 	rm -f $@
 	cp $? $@
+
+pngprefix.h: # is empty
+	:>$@
+endif
+
 $(srcdir)/scripts/pnglibconf.h.prebuilt:
 	@echo "Attempting to build $@" >&2
 	@echo "This is a machine generated file, but if you want to make" >&2
-	@echo "a new one simply make 'scripts/pnglibconf.out' and copy that" >&2
+	@echo "a new one simply make 'scripts/pnglibconf.out', copy that" >&2
+	@echo "AND set PNG_ZLIB_VERNUM to 0 (you MUST do this)" >&2
 	@exit 1
 
 # The following is necessary to ensure that the local pnglibconf.h is used, not
 # an installed one (this can happen immediately after on a clean system if
-# 'make test' is the first thing the user does.)
-contrib/libtests/pngvalid.o pngtest.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
@@ -142,47 +228,55 @@ SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0'\
 		-DSYMBOL_PREFIX='$(SYMBOL_PREFIX)'\
 		-DPNG_NO_USE_READ_MACROS -DPNG_BUILDING_SYMBOL_TABLE
 
+if DO_PNG_PREFIX
+SYMBOL_CFLAGS += -DPNG_PREFIX='@PNG_PREFIX@'
+endif
+
 .dfn.out:
-	rm -f $@ $@.c $@.?
+	rm -f $@ $*.c $*.tf[12]
 	test -d scripts || mkdir scripts || test -d scripts
-	echo '#include "$<"' >$@.c
-	$(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) @LIBPNG_DEFINES@\
-	    $(CPPFLAGS) $(SYMBOL_CFLAGS) $@.c > $@.1
-	$(AWK) -f "${srcdir}/scripts/dfn.awk" out="$@.2" $@.1 1>&2
-	mv $@.2 $@
+	echo '#include "$<"' >$*.c
+	$(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)\
+	    $(CPPFLAGS) $(SYMBOL_CFLAGS) $*.c > $*.tf1
+	$(AWK) -f "${srcdir}/scripts/dfn.awk" out="$*.tf2" $*.tf1 1>&2
+	rm -f $*.c $*.tf1
+	mv $*.tf2 $@
 
 # The .dfn file for pnglibconf.h is machine generated
 pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h pngusr.dfa $(DFA_XTRA)
-	rm -f $@ pnglibconf.pre $@.?
-	$(AWK) -f ${srcdir}/scripts/options.awk out="pnglibconf.pre"\
-	    version=search ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
+	rm -f $@ $*.tf[45]
+	$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf4 version=search\
+	    ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
 	    ${srcdir}/pngusr.dfa $(DFA_XTRA) 1>&2
-	$(AWK) -f ${srcdir}/scripts/options.awk out="$@.1" pnglibconf.pre 1>&2
-	mv $@.1 $@
+	$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf5 $*.tf4 1>&2
+	rm $*.tf4
+	mv $*.tf5 $@
 
 # Symbol checks (.def and .out files should match)
 scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.out
+
 .out.chk:
-	rm -f $@ symbols.new
+	rm -f $@ $*.new
 	$(AWK) -f ${srcdir}/scripts/checksym.awk ${srcdir}/scripts/${*F}.def\
-	    $< >&2
-	mv symbols.new $@
+	    of="$*.new" $< >&2
+	mv $*.new $@
 
 # used on demand to regenerate the standard header, CPPFLAGS should
 # be empty - no non-standard defines
 scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
-	rm -f $@ dfn?.out
+	rm -f $@ pnglibconf.tf[67]
 	test -z "$(CPPFLAGS)"
 	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
-	$(AWK) -f ${srcdir}/scripts/options.awk out=dfn1.out logunsupported=1\
-		version=search ${srcdir}/pngconf.h -\
-		${srcdir}/scripts/pnglibconf.dfa 1>&2
-	$(AWK) -f ${srcdir}/scripts/options.awk out=dfn2.out dfn1.out 1>&2
-	rm dfn1.out
-	mv dfn2.out $@
+	$(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf6\
+	    logunsupported=1 version=search ${srcdir}/pngconf.h -\
+	    ${srcdir}/scripts/pnglibconf.dfa 1>&2
+	$(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf7\
+	    pnglibconf.tf6 1>&2
+	rm pnglibconf.tf6
+	mv pnglibconf.tf7 $@
 
 $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS): png.h pngconf.h \
-	pnglibconf.h pngpriv.h pngdebug.h pnginfo.h pngstruct.h
+	pnglibconf.h pngpriv.h pngdebug.h pnginfo.h pngstruct.h pngprefix.h
 
 test: check-am
 
@@ -230,3 +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

@@ -1,12 +1,11 @@
-README for libpng version 1.5.18beta01 - August 21, 2013 (shared library 15.0)
+README for libpng version 1.6.8rc02 - December 14, 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.
 
-Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
-libpng-*.tar.xz or libpng-*.tar.bz2 if you want UNIX-style line endings
-in the text files, or lpng*.7z or lpng*.zip if you want DOS-style line
-endings.
+Libpng comes in several distribution formats.  Get libpng-*.tar.gz or
+libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
+or lpng*.7z or lpng*.zip if you want DOS-style line endings.
 
 Version 0.89 was the first official release of libpng.  Don't let the
 fact that it's the first release fool you.  The libpng library has been in
@@ -168,15 +167,17 @@ Files in this distribution:
       pngwutil.c    =>  Write utility functions
       arm           =>  Contains optimized code for the ARM platform
       contrib       =>  Contributions
+       examples         =>  Example programs
        gregbook         =>  source code for PNG reading and writing, from
                             Greg Roelofs' "PNG: The Definitive Guide",
                             O'Reilly, 1999
-       libtests         =>  Contains the pngvalid.c test program
+       libtests         =>  Test programs
        pngminim         =>  Minimal decoder, encoder, and progressive decoder
                             programs demonstrating use of pngusr.dfa
        pngminus         =>  Simple pnm2png and png2pnm programs
        pngsuite         =>  Test images
-       visupng          =>  Contains a MSVC workspace for VisualPng
+       tools            =>  Various tools
+       visupng      =>  Contains a MSVC workspace for VisualPng
       projects      =>  Contains project files and workspaces for
                         building a DLL
        owatcom          =>  Contains a WATCOM project for building libpng

arm/arm_init.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.5.17 [June 27, 2013]
+ * Last changed in libpng 1.6.6 [September 16, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -16,6 +16,7 @@
 
 #include "../pngpriv.h"
 
+#ifdef PNG_READ_SUPPORTED
 #if PNG_ARM_NEON_OPT > 0
 #ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
 #include <signal.h> /* for sig_atomic_t */
@@ -153,6 +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)
    {
@@ -177,13 +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
 
@@ -217,3 +229,4 @@ png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
    }
 }
 #endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_READ_SUPPORTED */

arm/filter_neon.S

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2013 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.5.17 [June 27, 2013]
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
  *
  * 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 +21,14 @@
 .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
 
 #ifdef __ELF__
@@ -233,3 +242,5 @@ func    png_read_filter_row_paeth3_neon, export=1
         pop             {r4,pc}
 endfunc
 #endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_READ_SUPPORTED */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */

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 [(PENDING RELEASE)]
+ *
+ * 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

@@ -1,34 +1,224 @@
 #! /bin/sh
-# a quick hack script to generate necessary files from 
-# auto* tools.
 #
-# WARNING: if you run this you will change the versions
-# of the tools which are used and, maybe, required!
+# Run 'autoreconf' to build 'configure', 'Makefile.in' and other configure
+# control files.
+#
+# The first time this is run on a GIT checkout the only files that exist are
+# configure.ac and Makefile.am; all of the autotools support scripts are
+# missing.  They are instantiated with autoreconf --force --install.
+#
+# 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 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 (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.
+#
+clean=
+maintainer=
+while test $# -gt 0
+do
+   case "$1" in
+      --maintainer)
+         maintainer=1;;
 
-# You can define your own replacements in your environment.
-# $AUTOCONF,  $AUTOMAKE, $AUTOHEADER, $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
+      --clean)
+         clean=1;;
 
-touch Makefile.am configure.ac
-{
-   LT=${LIBTOOLIZE-libtoolize}
-   echo "running $LT" >&2
-   $LT --force --copy --automake
-} && {
-   AL=${ACLOCAL-aclocal}
-   echo "running $AL" >&2
-   $AL
-} && {
-   AH=${AUTOHEADER-autoheader}
-   echo "running $AH [ignore the warnings]" >&2
-   $AH
-} && {
-   AM=${AUTOMAKE-automake}
-   echo "running $AM" >&2
-   $AM --force-missing --foreign -a -c
-} && {
-   AC=${AUTOCONF-autoconf}
-   echo "running $AC" >&2
-   $AC
-} &&
-   echo "autogen complete" >&2 ||
-   echo "ERROR: autogen.sh failed, autogen is incomplete" >&2
+      *)
+         exec >&2
+         echo "$0: usage: ./autogen.sh"
+         if test -d .git
+         then
+            echo "  ./autogen.sh generates the configure script and"
+            echo "  Makefile.in, or refreshes them after changes to Makefile.am"
+            echo "  or configure.ac.  You may prefer to just run autoreconf."
+         elif test -z "$maintainer"
+         then
+            echo "  DO NOT RUN THIS SCRIPT."
+            echo "  If you need to change Makefile.am or configure.ac then you"
+            echo "  also need to run ./configure --enable-maintainer-mode and"
+            echo "  use the appropriate autotools, *NOT* this script, to update"
+            echo "  everything, please check the documentation of autoreconf."
+            echo "  WARNING: libpng is intentionally generated with a known,"
+            echo "  fixed, set of autotools.  It is known *NOT* to work with"
+            echo "  the collection of autotools distributed on highly reputable"
+            echo "  operating systems."
+            echo "  Remember: autotools is GNU software, you are expected to"
+            echo "  pay for support."
+         else
+            echo "  You have run autogen.sh with --maintainer enabled and you"
+            echo "  are not using a GIT distribution, then you have given an"
+            echo "  unrecognized argument.  This is not good. --maintainer"
+            echo "  switches off any assumptions that you might not know what"
+            echo "  you are doing."
+         fi
+         exit 1;;
+   esac
+
+   shift
+done
+#
+# First check for a set of the autotools files; if absent then this is assumed
+# to be a GIT version and the local autotools must be used.  If present this
+# is a tarball distribution and the script should not be used.  If partially
+# present bad things are happening.
+#
+# The autotools generated files:
+libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in\
+   config.sub configure depcomp install-sh ltmain.sh missing test-driver"
+#
+# 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"
+
+libpng_autotools_dirs="autom4te.cache" # not required
+#
+# The configure generated files:
+libpng_configure_files="Makefile config.h config.log config.status\
+   libpng-config libpng.pc libtool stamp-h1"
+
+libpng_configure_dirs=".deps"
+#
+# We must remove the configure generated files as well as the autotools
+# generated files if autotools are regenerated because otherwise if configure
+# has been run without "--enable-maintainer-mode" make can do a partial update
+# 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(){
+   rm -rf $libpng_configure_files $libpng_configure_dirs
+}
+#
+# Clean: remove everything (this is to help with testing)
+if test -n "$clean"
+then
+   clean_configure
+   if test -n "$maintainer"
+   then
+      clean_autotools
+   fi
+
+   exit 0
+fi
+#
+# Validate the distribution.
+libpng_autotools_file_found=
+libpng_autotools_file_missing=
+for file in $libpng_autotools_files
+do
+   if test -f  "$file"
+   then
+      libpng_autotools_file_found=1
+   else
+      libpng_autotools_file_missing=1
+   fi
+done
+#
+# Presence of one of these does not *invalidate* missing, but absence
+# invalidates found.
+for file in $libpng_libtool_files
+do
+   if test ! -f "$file"
+   then
+      libpng_autotools_file_missing=1
+   fi
+done
+#
+# The cache directory doesn't matter - it will be regenerated and does not exist
+# anyway in a tarball.
+#
+# Either everything is missing or everything is there, the --maintainer option
+# just changes this so that the mode is set to generate all the files.
+mode=
+if test -z "$libpng_autotools_file_found" -o -n "$maintainer"
+then
+   mode="autoreconf"
+else
+   if test -n "$libpng_autotools_file_missing"
+   then
+      mode="broken"
+   else
+      mode="configure"
+   fi
+fi
+#
+# So:
+case "$mode" in
+   autoreconf)
+      # Clean in case configure files exist
+      clean_configure
+      clean_autotools
+      # Everything must be initialized, so use --force
+      if autoreconf --warnings=all --force --install
+      then
+         missing=
+         for file in $libpng_autotools_files
+         do
+            test -f "$file" || missing=1
+         done
+         # ignore the cache directory
+         test -z "$missing" || {
+            exec >&2
+            echo "autoreconf was run, but did not produce all the expected"
+            echo "files.  It is likely that your autotools installation is"
+            echo "not compatible with that expected by libpng."
+            exit 1
+         }
+      else
+         exec >&2
+         echo "autoreconf failed: your version of autotools is incompatible"
+         echo "with this libpng version.  Please use a distributed archive"
+         echo "(which includes the autotools generated files) and run configure"
+         echo "instead."
+         exit 1
+      fi;;
+
+   configure)
+      if test -d .git
+      then
+         exec >&2
+         echo "ERROR: running autoreconf on an initialized sytem"
+         echo "  This is not necessary; it is only necessary to remake the"
+         echo "  autotools generated files if Makefile.am or configure.ac"
+         echo "  change and make does the right thing with:"
+         echo
+         echo "     ./configure --enable-maintainer-mode."
+         echo
+         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 "  compatibility with prior releases."
+         exit 1
+      else
+         exec >&2
+         echo "autogen.sh is intended only to generate 'configure' on systems"
+         echo "that do not have it.  You have a complete 'configure', if you"
+         echo "need to change Makefile.am or configure.ac you also need to"
+         echo "run configure with the --enable-maintainer-mode option."
+         exit 1
+      fi;;
+
+   broken)
+      exec >&2
+      echo "Your system has a partial set of autotools generated files."
+      echo "autogen.sh is unable to proceed.  The full set of files is"
+      echo "contained in the libpng 'tar' distribution archive and you do"
+      echo "not need to run autogen.sh if you use it."
+      exit 1;;
+esac

config.h.in

@@ -1,112 +0,0 @@
-/* config.h.in.  Generated from configure.ac by autoheader.  */
-
-/* Define to 1 if you have the <dlfcn.h> header file. */
-#undef HAVE_DLFCN_H
-
-/* Define to 1 if you have the `feenableexcept' function. */
-#undef HAVE_FEENABLEEXCEPT
-
-/* Define to 1 if you have the <inttypes.h> header file. */
-#undef HAVE_INTTYPES_H
-
-/* Define to 1 if you have the `m' library (-lm). */
-#undef HAVE_LIBM
-
-/* Define to 1 if you have the `z' library (-lz). */
-#undef HAVE_LIBZ
-
-/* Define to 1 if you have the <malloc.h> header file. */
-#undef HAVE_MALLOC_H
-
-/* Define to 1 if you have the <memory.h> header file. */
-#undef HAVE_MEMORY_H
-
-/* Define to 1 if you have the `memset' function. */
-#undef HAVE_MEMSET
-
-/* Define to 1 if you have the `pow' function. */
-#undef HAVE_POW
-
-/* Define to 1 if you have the <stdint.h> header file. */
-#undef HAVE_STDINT_H
-
-/* Define to 1 if you have the <stdlib.h> header file. */
-#undef HAVE_STDLIB_H
-
-/* Define to 1 if you have the <strings.h> header file. */
-#undef HAVE_STRINGS_H
-
-/* Define to 1 if you have the <string.h> header file. */
-#undef HAVE_STRING_H
-
-/* Define to 1 if you have the <sys/stat.h> header file. */
-#undef HAVE_SYS_STAT_H
-
-/* Define to 1 if you have the <sys/types.h> header file. */
-#undef HAVE_SYS_TYPES_H
-
-/* Define to 1 if you have the <unistd.h> header file. */
-#undef HAVE_UNISTD_H
-
-/* Define to the sub-directory in which libtool stores uninstalled libraries.
-   */
-#undef LT_OBJDIR
-
-/* Name of package */
-#undef PACKAGE
-
-/* Define to the address where bug reports for this package should be sent. */
-#undef PACKAGE_BUGREPORT
-
-/* Define to the full name of this package. */
-#undef PACKAGE_NAME
-
-/* Define to the full name and version of this package. */
-#undef PACKAGE_STRING
-
-/* Define to the one symbol short name of this package. */
-#undef PACKAGE_TARNAME
-
-/* Define to the home page for this package. */
-#undef PACKAGE_URL
-
-/* Define to the version of this package. */
-#undef PACKAGE_VERSION
-
-/* Turn on ARM Neon optimizations at run-time */
-#undef PNG_ARM_NEON_API_SUPPORTED
-
-/* Check for ARM Neon support at run-time */
-#undef PNG_ARM_NEON_CHECK_SUPPORTED
-
-/* Enable ARM Neon optimizations */
-#undef PNG_ARM_NEON_OPT
-
-/* Define to 1 if you have the ANSI C header files. */
-#undef STDC_HEADERS
-
-/* Define to 1 if your <sys/time.h> declares `struct tm'. */
-#undef TM_IN_SYS_TIME
-
-/* Version number of package */
-#undef VERSION
-
-/* Define to empty if `const' does not conform to ANSI C. */
-#undef const
-
-/* Define to the equivalent of the C99 'restrict' keyword, or to
-   nothing if this is not supported.  Do not define if restrict is
-   supported directly.  */
-#undef restrict
-/* Work around a bug in Sun C++: it does not support _Restrict or
-   __restrict__, even though the corresponding Sun C compiler ends up with
-   "#define restrict _Restrict" or "#define restrict __restrict__" in the
-   previous line.  Perhaps some future version of Sun C++ will work with
-   restrict; if so, hopefully it defines __RESTRICT like Sun C does.  */
-#if defined __SUNPRO_CC && !defined __RESTRICT
-# define _Restrict
-# define __restrict__
-#endif
-
-/* Define to `unsigned int' if <sys/types.h> does not define. */
-#undef size_t

configure.ac

@@ -14,19 +14,35 @@ dnl Makefile.am to upgrade the package name.
 dnl This is here to prevent earlier autoconf from being used, it
 dnl should not be necessary to regenerate configure if the time
 dnl stamps are correct
-AC_PREREQ(2.59)
+AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng], [1.5.18beta01], [png-mng-implement@lists.sourceforge.net])
-AM_INIT_AUTOMAKE([serial-tests])
-dnl stop configure from automagically running automake
+AC_INIT([libpng],[1.6.8rc02],[png-mng-implement@lists.sourceforge.net])
+AC_CONFIG_MACRO_DIR([scripts])
+
+# libpng does not follow GNU file name conventions (hence 'foreign')
+# color-tests requires automake 1.11 or later
+# silent-rules requires automake 1.11 or later
+# 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 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
 AM_MAINTAINER_MODE
 
-PNGLIB_VERSION=1.5.18beta01
+dnl configure.ac and Makefile.am expect automake 1.11.2 or a compatible later
+dnl version; aclocal.m4 will generate a failure if you use a prior version of
+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=1.6.8rc02
 PNGLIB_MAJOR=1
-PNGLIB_MINOR=5
-PNGLIB_RELEASE=18
+PNGLIB_MINOR=6
+PNGLIB_RELEASE=8
 
 dnl End of version number stuff
 
@@ -37,18 +53,62 @@ AC_CONFIG_HEADERS([config.h])
 AC_LANG([C])
 AC_PROG_CC
 AM_PROG_AS
-AC_PROG_LD
+LT_PATH_LD
 AC_PROG_CPP
-AC_PROG_SED
 AC_PROG_AWK
 AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
+
+dnl libtool/libtoolize; version 2.4.2 is the tested version, this or any
+dnl compatible later version may be used
 LT_INIT([win32-dll])
+LT_PREREQ([2.4.2])
+
+# Some awks crash when confronted with pnglibconf.dfa, do a test run now
+# to make sure this doesn't happen
+AC_MSG_CHECKING([that AWK works])
+if ${AWK} -f ${srcdir}/scripts/options.awk out="/dev/null" version=search\
+   ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
+   ${srcdir}/pngusr.dfa 1>&2
+then
+   AC_MSG_RESULT([ok])
+else
+   AC_MSG_FAILURE([failed], 1)
+fi
+
+# This is a remnant of the old cc -E validation, where it may have been
+# necessary to use a different preprocessor for .dfn files
+DFNCPP="$CPP"
+AC_SUBST(DFNCPP)
+
+# -Werror cannot be passed to GCC in CFLAGS because configure will fail (it
+# checks the compiler with a program that generates a warning), add the
+# following option to deal with this
+AC_ARG_VAR(PNG_COPTS,
+   [additional flags for the C compiler, use this for options that would]
+   [cause configure itself to fail])
+AC_ARG_ENABLE(werror,
+   AS_HELP_STRING([[[--enable-werror[=OPT]]]],
+      [Pass -Werror or the given argument to the compiler if it is supported]),
+   [test "$enable_werror" = "yes" && enable_werror="-Werror"
+    if test "$enable_werror" != "no"; then
+      sav_CFLAGS="$CFLAGS"
+      CFLAGS="$enable_werror $CFLAGS"
+      AC_MSG_CHECKING([if the compiler allows $enable_werror])
+      AC_COMPILE_IFELSE(
+         [AC_LANG_SOURCE([
+            [int main(int argc, char **argv){]
+            [return argv[argc-1][0];]
+            [}]])],
+         AC_MSG_RESULT(yes)
+         PNG_COPTS="$PNG_COPTS $enable_werror",
+         AC_MSG_RESULT(no))
+      CFLAGS="$sav_CFLAGS"
+    fi],)
 
 # Checks for header files.
 AC_HEADER_STDC
-AC_CHECK_HEADERS([malloc.h stdlib.h string.h strings.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
@@ -56,23 +116,17 @@ AC_TYPE_SIZE_T
 AC_STRUCT_TM
 AC_C_RESTRICT
 
-# This is a remnant of the old cc -E validation, where it may have been
-# necessary to use a different preprocessor for .dfn files
-DFNCPP="$CPP"
-AC_SUBST(DFNCPP)
-
 # Checks for library functions.
 AC_FUNC_STRTOD
-AC_CHECK_FUNCS([memset], , AC_ERROR([memset not found in libc]))
-AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_ERROR([cannot find pow])) )
+AC_CHECK_FUNCS([memset], , AC_MSG_ERROR(memset not found in libc))
+AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_MSG_ERROR(cannot find pow)) )
 AC_ARG_WITH(zlib-prefix,
-   AC_HELP_STRING([--with-zlib-prefix],
-                  [prefix that may have been used in installed zlib]),
-                  [ZPREFIX=${withval}],
-                  [ZPREFIX='z_'])
+   AS_HELP_STRING([[[--with-zlib-prefix]]],
+      [prefix that may have been used in installed zlib]),
+      [ZPREFIX=${withval}],
+      [ZPREFIX='z_'])
 AC_CHECK_LIB(z, zlibVersion, ,
-    AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, ,
-                 AC_ERROR([zlib not installed])))
+    AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, , AC_MSG_ERROR(zlib not installed)))
 
 # The following is for pngvalid, to ensure it catches FP errors even on
 # platforms that don't enable FP exceptions, the function appears in the math
@@ -80,10 +134,6 @@ AC_CHECK_LIB(z, zlibVersion, ,
 AC_CHECK_LIB([m], [feenableexcept])
 AC_CHECK_FUNCS([feenableexcept])
 
-LIBPNG_DEFINES=-DPNG_CONFIGURE_LIBPNG
-LIBPNG_DEFINES=$LIBPNG_DEFINES
-AC_SUBST(LIBPNG_DEFINES)
-
 AC_MSG_CHECKING([if using Solaris linker])
 SLD=`$LD --version 2>&1 | grep Solaris`
 if test "$SLD"; then
@@ -144,28 +194,38 @@ AC_SUBST(PNGLIB_RELEASE)
 # Additional arguments (and substitutions)
 # Allow the pkg-config directory to be set
 AC_ARG_WITH(pkgconfigdir,
-	AC_HELP_STRING([--with-pkgconfigdir],
-	[Use the specified pkgconfig dir (default is libdir/pkgconfig)]),
-	[pkgconfigdir=${withval}],
-	[pkgconfigdir='${libdir}/pkgconfig'])
+   AS_HELP_STRING([[[--with-pkgconfigdir]]],
+      [Use the specified pkgconfig dir (default is libdir/pkgconfig)]),
+   [pkgconfigdir=${withval}],
+   [pkgconfigdir='${libdir}/pkgconfig'])
 
 AC_SUBST([pkgconfigdir])
-AC_MSG_NOTICE([pkgconfig directory is ${pkgconfigdir}])
+AC_MSG_NOTICE([[pkgconfig directory is ${pkgconfigdir}]])
 
 # Make the *-config binary config scripts optional
 AC_ARG_WITH(binconfigs,
-	AC_HELP_STRING([--with-binconfigs],
-		[Generate shell libpng-config scripts as well as pkg-config data]
-		[@<:@default=yes@:>@]),
-	[if test "${withval}" = no; then
-		binconfigs=
-		AC_MSG_NOTICE([libpng-config scripts will not be built])
-	else
-		binconfigs='${binconfigs}'
-	fi],
-	[binconfigs='${binconfigs}'])
+   AS_HELP_STRING([[[--with-binconfigs]]],
+      [Generate shell libpng-config scripts as well as pkg-config data]
+      [@<:@default=yes@:>@]),
+   [if test "${withval}" = no; then
+      binconfigs=
+      AC_MSG_NOTICE([[libpng-config scripts will not be built]])
+    else
+      binconfigs='${binconfigs}'
+    fi],
+   [binconfigs='${binconfigs}'])
 AC_SUBST([binconfigs])
 
+# Support for prefixes to the API function names; this will generate defines
+# at the start of the build to rename exported library functions
+AC_ARG_WITH(libpng-prefix,
+   AS_HELP_STRING([[[--with-libpng-prefix]]],
+      [prefix libpng exported function (API) names with the given value]),
+   [if test "${withval:-no}" != "no"; then
+      AC_SUBST([PNG_PREFIX], [${withval}])
+    fi])
+AM_CONDITIONAL([DO_PNG_PREFIX], [test "${with_libpng_prefix:-no}" != "no"])
+
 # HOST SPECIFIC OPTIONS
 # =====================
 #
@@ -214,12 +274,12 @@ AM_CONDITIONAL([PNG_ARM_NEON],
       arm*) :;;
       *)    test "$enable_arm_neon" != '';;
     esac])
- 
+
 AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
 
 # Config files, substituting as above
 AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in])
 AC_CONFIG_FILES([libpng-config:libpng-config.in],
-		[chmod +x libpng-config])
+   [chmod +x libpng-config])
 
 AC_OUTPUT

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/examples/README.txt

@@ -0,0 +1,24 @@
+
+This directory (contrib/examples) contains examples of libpng usage.
+
+NO COPYRIGHT RIGHTS ARE CLAIMED TO ANY OF THE FILES IN THIS DIRECTORY.
+
+To the extent possible under law, the authors have waived all copyright and
+related or neighboring rights to this work.  This work is published from:
+United States.
+
+The files may be used freely in any way.  The intention is that appropriate
+parts of the files be used in other libpng-using programs without any need for
+the authors of the using code to seek copyright or license from the original
+authors.
+
+The source code and comments in this directory are the original work of the
+people named below.  No other person or organization has made contributions to
+the work in this directory.
+
+ORIGINAL AUTHORS
+    The following people have contributed to the code in this directory.  None
+    of the people below claim any rights with regard to the contents of this
+    directory.
+
+    John Bowler <jbowler@acm.org>

contrib/examples/iccfrompng.c

@@ -0,0 +1,180 @@
+/*- iccfrompng
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * 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.
+ *
+ * Extract any icc profiles found in the given PNG files.  This is a simple
+ * example of a program which extracts information from the header of a PNG file
+ * without processing the image.  Notice that some header information may occur
+ * after the image data, textual data and comments are an example; the approach
+ * in this file won't work reliably for such data because it only looks for the
+ * information in the section of the file that preceeds the image data.
+ *
+ * Compile and link against libpng and zlib, plus anything else required on the
+ * system you use.
+ *
+ * To use supply a list of PNG files containing iCCP chunks, the chunks will be
+ * extracted to a similarly named file with the extension replaced by 'icc',
+ * which will be overwritten without warning.
+ */
+#include <stdlib.h>
+#include <setjmp.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <png.h>
+
+static int verbose = 1;
+static png_byte no_profile[] = "no profile";
+
+static png_bytep
+extract(FILE *fp, png_uint_32 *proflen)
+{
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+   png_infop info_ptr = NULL;
+   png_bytep result = NULL;
+
+   /* Initialize for error or no profile: */
+   *proflen = 0;
+
+   if (png_ptr == NULL)
+   {
+      fprintf(stderr, "iccfrompng: version library mismatch?\n");
+      return 0;
+   }
+
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+      return 0;
+   }
+
+   png_init_io(png_ptr, fp);
+
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
+      png_error(png_ptr, "OOM allocating info structure");
+
+   png_read_info(png_ptr, info_ptr);
+
+   {
+      png_charp name;
+      int compression_type;
+      png_bytep profile;
+
+      if (png_get_iCCP(png_ptr, info_ptr, &name, &compression_type, &profile,
+         proflen) & PNG_INFO_iCCP)
+      {
+         result = malloc(*proflen);
+         if (result != NULL)
+            memcpy(result, profile, *proflen);
+
+         else
+            png_error(png_ptr, "OOM allocating profile buffer");
+      }
+
+      else
+	result = no_profile;
+   }
+
+   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+   return result;
+}
+
+static int
+extract_one_file(const char *filename)
+{
+   int result = 0;
+   FILE *fp = fopen(filename, "rb");
+
+   if (fp != NULL)
+   {
+      png_uint_32 proflen = 0;
+      png_bytep profile = extract(fp, &proflen);
+
+      if (profile != NULL && profile != no_profile)
+      {
+         size_t len;
+         char *output;
+
+         {
+            const char *ep = strrchr(filename, '.');
+
+            if (ep != NULL)
+               len = ep-filename;
+
+            else
+               len = strlen(filename);
+         }
+
+         output = malloc(len + 5);
+         if (output != NULL)
+         {
+            FILE *of;
+
+            memcpy(output, filename, len);
+            strcpy(output+len, ".icc");
+
+            of = fopen(output, "wb");
+            if (of != NULL)
+            {
+               if (fwrite(profile, proflen, 1, of) == 1 &&
+                  fflush(of) == 0 &&
+                  fclose(of) == 0)
+               {
+                  if (verbose)
+                     printf("%s -> %s\n", filename, output);
+                  /* Success return */
+                  result = 1;
+               }
+
+               else
+               {
+                  fprintf(stderr, "%s: error writing profile\n", output);
+                  if (remove(output))
+                     fprintf(stderr, "%s: could not remove file\n", output);
+               }
+            }
+
+            else
+               fprintf(stderr, "%s: failed to open output file\n", output);
+
+            free(output);
+         }
+
+         else
+            fprintf(stderr, "%s: OOM allocating string!\n", filename);
+
+         free(profile);
+      }
+
+      else if (verbose && profile == no_profile)
+	printf("%s has no profile\n", filename);
+   }
+
+   else
+      fprintf(stderr, "%s: could not open file\n", filename);
+
+   return result;
+}
+
+int
+main(int argc, char **argv)
+{
+   int i;
+   int extracted = 0;
+
+   for (i=1; i<argc; ++i)
+   {
+      if (strcmp(argv[i], "-q") == 0)
+         verbose = 0;
+
+      else if (extract_one_file(argv[i]))
+         extracted = 1;
+   }
+
+   /* Exit code is true if any extract succeeds */
+   return extracted == 0;
+}

contrib/examples/pngpixel.c

@@ -0,0 +1,368 @@
+/*- pngpixel
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Read a single pixel value from a PNG file.
+ *
+ * This code illustrates basic 'by-row' reading of a PNG file using libpng.
+ * Rows are read until a particular pixel is found, the value of this pixel is
+ * then printed on stdout.
+ *
+ * The code illustrates how to do this on interlaced as well as non-interlaced
+ * images.  Normally you would call png_set_interlace_handling() to have libpng
+ * deal with the interlace for you, but that obliges you to buffer half of the
+ * image to assemble the interlaced rows.  In this code
+ * png_set_interlace_handling() is not called and, instead, the code handles the
+ * interlace passes directly looking for the required pixel.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <setjmp.h> /* required for error handling */
+
+/* Normally use <png.h> here to get the installed libpng, but this is done to
+ * ensure the code picks up the local libpng implementation:
+ */
+#include "../../png.h"
+
+/* Return component 'c' of pixel 'x' from the given row. */
+static unsigned int
+component(png_const_bytep row, png_uint_32 x, unsigned int c,
+   unsigned int bit_depth, unsigned int channels)
+{
+   /* PNG images can be up to 2^31 pixels wide, but this means they can be up to
+    * 2^37 bits wide (for a 64-bit pixel - the largest possible) and hence 2^34
+    * bytes wide.  Since the row fitted into memory, however, the following must
+    * work:
+    */
+   png_uint_32 bit_offset_hi = bit_depth * ((x >> 6) * channels);
+   png_uint_32 bit_offset_lo = bit_depth * ((x & 0x3f) * channels + c);
+
+   row = (png_const_bytep)(((PNG_CONST png_byte (*)[8])row) + bit_offset_hi);
+   row += bit_offset_lo >> 3;
+   bit_offset_lo &= 0x07;
+
+   /* PNG pixels are packed into bytes to put the first pixel in the highest
+    * bits of the byte and into two bytes for 16-bit values with the high 8 bits
+    * first, so:
+    */
+   switch (bit_depth)
+   {
+      case 1: return (row[0] >> (7-bit_offset_lo)) & 0x01;
+      case 2: return (row[0] >> (6-bit_offset_lo)) & 0x03;
+      case 4: return (row[0] >> (4-bit_offset_lo)) & 0x0f;
+      case 8: return row[0];
+      case 16: return (row[0] << 8) + row[1];
+      default:
+         /* This should never happen, it indicates a bug in this program or in
+          * libpng itself:
+          */
+         fprintf(stderr, "pngpixel: invalid bit depth %u\n", bit_depth);
+         exit(1);
+   }
+}
+
+/* Print a pixel from a row returned by libpng; determine the row format, find
+ * the pixel, and print the relevant information to stdout.
+ */
+static void
+print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
+   png_uint_32 x)
+{
+   PNG_CONST unsigned int bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+
+   switch (png_get_color_type(png_ptr, info_ptr))
+   {
+      case PNG_COLOR_TYPE_GRAY:
+         printf("GRAY %u\n", component(row, x, 0, bit_depth, 1));
+         return;
+
+      /* The palette case is slightly more difficult - the palette and, if
+       * present, the tRNS ('transparency', though the values are really
+       * opacity) data must be read to give the full picture:
+       */
+      case PNG_COLOR_TYPE_PALETTE:
+         {
+            PNG_CONST unsigned int index = component(row, x, 0, bit_depth, 1);
+            png_colorp palette = NULL;
+            int num_palette = 0;
+
+            if ((png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) &
+               PNG_INFO_PLTE) && num_palette > 0 && palette != NULL)
+            {
+               png_bytep trans_alpha = NULL;
+               int num_trans = 0;
+               if ((png_get_tRNS(png_ptr, info_ptr, &trans_alpha, &num_trans,
+                  NULL) & PNG_INFO_tRNS) && num_trans > 0 &&
+                  trans_alpha != NULL)
+                  printf("INDEXED %u = %d %d %d %d\n", index,
+                     palette[index].red, palette[index].green,
+                     palette[index].blue,
+                     index < num_trans ? trans_alpha[index] : 255);
+
+               else /* no transparency */
+                  printf("INDEXED %u = %d %d %d\n", index,
+                     palette[index].red, palette[index].green,
+                     palette[index].blue);
+            }
+
+            else
+               printf("INDEXED %u = invalid index\n", index);
+         }
+         return;
+
+      case PNG_COLOR_TYPE_RGB:
+         printf("RGB %u %u %u\n", component(row, x, 0, bit_depth, 3),
+            component(row, x, 1, bit_depth, 3),
+            component(row, x, 2, bit_depth, 3));
+         return;
+
+      case PNG_COLOR_TYPE_GRAY_ALPHA:
+         printf("GRAY+ALPHA %u %u\n", component(row, x, 0, bit_depth, 2),
+            component(row, x, 1, bit_depth, 2));
+         return;
+
+      case PNG_COLOR_TYPE_RGB_ALPHA:
+         printf("RGBA %u %u %u %u\n", component(row, x, 0, bit_depth, 4),
+            component(row, x, 1, bit_depth, 4),
+            component(row, x, 2, bit_depth, 4),
+            component(row, x, 3, bit_depth, 4));
+         return;
+
+      default:
+         png_error(png_ptr, "invalid color type");
+   }
+}
+
+int main(int argc, const char **argv)
+{
+   /* This program uses the default, <setjmp.h> based, libpng error handling
+    * mechanism, therefore any local variable that exists before the call to
+    * setjmp and is changed after the call to setjmp returns successfully must
+    * be declared with 'volatile' to ensure that their values don't get
+    * destroyed by longjmp:
+    */
+   volatile int result = 1/*fail*/;
+
+   if (argc == 4)
+   {
+      long x = atol(argv[1]);
+      long y = atol(argv[2]);
+      FILE *f = fopen(argv[3], "rb");
+      volatile png_bytep row = NULL;
+
+      if (f != NULL)
+      {
+         /* libpng requires a callback function for handling errors; this
+          * callback must not return.  The default callback function uses a
+          * stored <setjmp.h> style jmp_buf which is held in a png_struct and
+          * writes error messages to stderr.  Creating the png_struct is a
+          * little tricky; just copy the following code.
+          */
+         png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
+            NULL, NULL, NULL);
+
+         if (png_ptr != NULL)
+         {
+            png_infop info_ptr = png_create_info_struct(png_ptr);
+
+            if (info_ptr != NULL)
+            {
+               /* Declare stack variables to hold pointers to locally allocated
+                * data.
+                */
+
+               /* Initialize the error control buffer: */
+               if (setjmp(png_jmpbuf(png_ptr)) == 0)
+               {
+                  png_uint_32 width, height;
+                  int bit_depth, color_type, interlace_method,
+                     compression_method, filter_method;
+                  png_bytep row_tmp;
+
+                  /* Now associate the recently opened (FILE*) with the default
+                   * libpng initialization functions.  Sometimes libpng is
+                   * compiled without stdio support (it can be difficult to do
+                   * in some environments); in that case you will have to write
+                   * your own read callback to read data from the (FILE*).
+                   */
+                  png_init_io(png_ptr, f);
+
+                  /* And read the first part of the PNG file - the header and
+                   * all the information up to the first pixel.
+                   */
+                  png_read_info(png_ptr, info_ptr);
+
+                  /* This fills in enough information to tell us the width of
+                   * each row in bytes, allocate the appropriate amount of
+                   * space.  In this case png_malloc is used - it will not
+                   * return if memory isn't available.
+                   */
+                  row = png_malloc(png_ptr, png_get_rowbytes(png_ptr,
+                     info_ptr));
+
+                  /* To avoid the overhead of using a volatile auto copy row_tmp
+                   * to a local here - just use row for the png_free below.
+                   */
+                  row_tmp = row;
+
+                  /* All the information we need is in the header is returned by
+                   * png_get_IHDR, if this fails we can now use 'png_error' to
+                   * signal the error and return control to the setjmp above.
+                   */
+                  if (png_get_IHDR(png_ptr, info_ptr, &width, &height,
+                     &bit_depth, &color_type, &interlace_method,
+                     &compression_method, &filter_method))
+                  {
+                     int passes, pass;
+
+                     /* png_set_interlace_handling returns the number of
+                      * passes required as well as turning on libpng's
+                      * handling, but since we do it ourselves this is
+                      * necessary:
+                      */
+                     switch (interlace_method)
+                     {
+                        case PNG_INTERLACE_NONE:
+                           passes = 1;
+                           break;
+
+                        case PNG_INTERLACE_ADAM7:
+                           passes = PNG_INTERLACE_ADAM7_PASSES;
+                           break;
+
+                        default:
+                           png_error(png_ptr, "pngpixel: unknown interlace");
+                     }
+
+                     /* Now read the pixels, pass-by-pass, row-by-row: */
+                     png_start_read_image(png_ptr);
+
+                     for (pass=0; pass<passes; ++pass)
+                     {
+                        png_uint_32 ystart, xstart, ystep, xstep;
+                        png_uint_32 py;
+
+                        if (interlace_method == PNG_INTERLACE_ADAM7)
+                        {
+                           /* Sometimes the whole pass is empty because the
+                            * image is too narrow or too short.  libpng
+                            * expects to be called for each row that is
+                            * present in the pass, so it may be necessary to
+                            * skip the loop below (over py) if the image is
+                            * too narrow.
+                            */
+                           if (PNG_PASS_COLS(width, pass) == 0)
+                              continue;
+
+                           /* We need the starting pixel and the offset
+                            * between each pixel in this pass; use the macros
+                            * in png.h:
+                            */
+                           xstart = PNG_PASS_START_COL(pass);
+                           ystart = PNG_PASS_START_ROW(pass);
+                           xstep = PNG_PASS_COL_OFFSET(pass);
+                           ystep = PNG_PASS_ROW_OFFSET(pass);
+                        }
+
+                        else
+                        {
+                           ystart = xstart = 0;
+                           ystep = xstep = 1;
+                        }
+
+                        /* To find the pixel, loop over 'py' for each pass
+                         * reading a row and then checking to see if it
+                         * contains the pixel.
+                         */
+                        for (py = ystart; py < height; py += ystep)
+                        {
+                           png_uint_32 px, ppx;
+
+                           /* png_read_row takes two pointers.  When libpng
+                            * handles the interlace the first is filled in
+                            * pixel-by-pixel, and the second receives the same
+                            * pixels but they are replicated across the
+                            * unwritten pixels so far for each pass.  When we
+                            * do the interlace, however, they just contain
+                            * the pixels from the interlace pass - giving
+                            * both is wasteful and pointless, so we pass a
+                            * NULL pointer.
+                            */
+                           png_read_row(png_ptr, row_tmp, NULL);
+
+                           /* Now find the pixel if it is in this row; there
+                            * are, of course, much better ways of doing this
+                            * than using a for loop:
+                            */
+                           if (y == py) for (px = xstart, ppx = 0;
+                              px < width; px += xstep, ++ppx) if (x == px)
+                           {
+                              /* 'ppx' is the index of the pixel in the row
+                               * buffer.
+                               */
+                              print_pixel(png_ptr, info_ptr, row_tmp, ppx);
+
+                              /* Now terminate the loops early - we have
+                               * found and handled the required data.
+                               */
+                              goto pass_loop_end;
+                           } /* x loop */
+                        } /* y loop */
+                     } /* pass loop */
+
+                     /* Finally free the temporary buffer: */
+                  pass_loop_end:
+                     row = NULL;
+                     png_free(png_ptr, row_tmp);
+                  }
+
+                  else
+                     png_error(png_ptr, "pngpixel: png_get_IHDR failed");
+
+               }
+
+               else
+               {
+                  /* Else libpng has raised an error.  An error message has
+                   * already been output, so it is only necessary to clean up
+                   * locally allocated data:
+                   */
+                  if (row != NULL)
+                  {
+                     /* The default implementation of png_free never errors out
+                      * (it just crashes if something goes wrong), but the safe
+                      * way of using it is still to clear 'row' before calling
+                      * png_free:
+                      */
+                     png_bytep row_tmp = row;
+                     row = NULL;
+                     png_free(png_ptr, row_tmp);
+                  }
+               }
+
+               png_destroy_info_struct(png_ptr, &info_ptr);
+            }
+
+            else
+               fprintf(stderr, "pngpixel: out of memory allocating png_info\n");
+
+            png_destroy_read_struct(&png_ptr, NULL, NULL);
+         }
+
+         else
+            fprintf(stderr, "pngpixel: out of memory allocating png_struct\n");
+      }
+
+      else
+         fprintf(stderr, "pngpixel: %s: could not open file\n", argv[3]);
+   }
+
+   else
+      /* Wrong number of arguments */
+      fprintf(stderr, "pngpixel: usage: pngpixel x y png-file\n");
+
+   return result;
+}

contrib/examples/pngtopng.c

@@ -0,0 +1,92 @@
+/*- pngtopng
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Read a PNG and write it out in a fixed format, using the 'simplified API'
+ * that was introduced in libpng-1.6.0.
+ *
+ * This sample code is just the code from the top of 'example.c' with some error
+ * handling added.  See example.c for more comments.
+ */
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+/* Normally use <png.h> here to get the installed libpng, but this is done to
+ * ensure the code picks up the local libpng implementation:
+ */
+#include "../../png.h"
+
+int main(int argc, const char **argv)
+{
+   int result = 1;
+
+   if (argc == 3)
+   {
+      png_image image;
+
+      /* Only the image structure version number needs to be set. */
+      memset(&image, 0, sizeof image);
+      image.version = PNG_IMAGE_VERSION;
+
+      if (png_image_begin_read_from_file(&image, argv[1]))
+      {
+         png_bytep buffer;
+
+         /* Change this to try different formats!  If you set a colormap format
+          * then you must also supply a colormap below.
+          */
+         image.format = PNG_FORMAT_RGBA;
+
+         buffer = malloc(PNG_IMAGE_SIZE(image));
+
+         if (buffer != NULL)
+         {
+            if (png_image_finish_read(&image, NULL/*background*/, buffer,
+               0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */))
+            {
+               if (png_image_write_to_file(&image, argv[2],
+                  0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
+                  NULL/*colormap*/))
+                  result = 0;
+
+               else
+                  fprintf(stderr, "pngtopng: write %s: %s\n", argv[2],
+                      image.message);
+
+               free(buffer);
+            }
+
+            else
+            {
+               fprintf(stderr, "pngtopng: read %s: %s\n", argv[1],
+                   image.message);
+
+               /* This is the only place where a 'free' is required; libpng does
+                * the cleanup on error and success, but in this case we couldn't
+                * complete the read because of running out of memory.
+                */
+               png_image_free(&image);
+            }
+         }
+
+         else
+            fprintf(stderr, "pngtopng: out of memory: %lu bytes\n",
+               (unsigned long)PNG_IMAGE_SIZE(image));
+      }
+
+      else
+         /* Failed to read the first argument: */
+         fprintf(stderr, "pngtopng: %s: %s\n", argv[1], image.message);
+   }
+
+   else
+      /* Wrong number of arguments */
+      fprintf(stderr, "pngtopng: usage: pngtopng input-file output-file\n");
+
+   return result;
+}

contrib/gregbook/Makefile.sgi

@@ -23,9 +23,9 @@
 
 # macros --------------------------------------------------------------------
 
-PNGINC = -I/usr/local/include/libpng15
-PNGLIB = -L/usr/local/lib -lpng15	  # dynamically linked against libpng
-#PNGLIB = /usr/local/lib/libpng15.a # statically linked against libpng
+PNGINC = -I/usr/local/include/libpng16
+PNGLIB = -L/usr/local/lib -lpng16	  # dynamically linked against libpng
+#PNGLIB = /usr/local/lib/libpng16.a # statically linked against libpng
 # or:
 #PNGINC = -I../..
 #PNGLIB = -L../.. -lpng

contrib/gregbook/Makefile.unx

@@ -26,14 +26,14 @@
 # macros --------------------------------------------------------------------
 
 #PNGDIR = /usr/local/lib
-#PNGINC = -I/usr/local/include/libpng15
-#PNGLIBd = -L$(PNGDIR) -lpng15 # dynamically linked, installed libpng
-#PNGLIBs = $(PNGDIR)/libpng15.a # statically linked, installed libpng
+#PNGINC = -I/usr/local/include/libpng16
+#PNGLIBd = -L$(PNGDIR) -lpng16 # dynamically linked, installed libpng
+#PNGLIBs = $(PNGDIR)/libpng16.a # statically linked, installed libpng
 # or:
 PNGDIR = ../..#	this one is for libpng-x.y.z/contrib/gregbook builds
 #PNGDIR = ../libpng
 PNGINC = -I$(PNGDIR)
-PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng15	# dynamically linked
+PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng16	# dynamically linked
 PNGLIBs = $(PNGDIR)/libpng.a		# statically linked, local libpng
 
 ZDIR = /usr/local/lib

contrib/gregbook/readpng2.c

@@ -136,29 +136,23 @@ int readpng2_init(mainprog_info *mainprog_ptr)
      * used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
      * IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
     {
-        /* These byte strings were copied from png.h.  If a future libpng
-         * version recognizes more chunks, add them to this list.  If a
-         * future version of readpng2.c recognizes more chunks, delete them
-         * from this list. */
-        static /* const */ png_byte chunks_to_ignore[] = {
-             99,  72,  82,  77, '\0',  /* cHRM */
-            104,  73,  83,  84, '\0',  /* hIST */
-            105,  67,  67,  80, '\0',  /* iCCP */
-            105,  84,  88, 116, '\0',  /* iTXt */
-            111,  70,  70, 115, '\0',  /* oFFs */
-            112,  67,  65,  76, '\0',  /* pCAL */
-            112,  72,  89, 115, '\0',  /* pHYs */
-            115,  66,  73,  84, '\0',  /* sBIT */
-            115,  67,  65,  76, '\0',  /* sCAL */
-            115,  80,  76,  84, '\0',  /* sPLT */
-            115,  84,  69,  82, '\0',  /* sTER */
-            116,  69,  88, 116, '\0',  /* tEXt */
-            116,  73,  77,  69, '\0',  /* tIME */
-            122,  84,  88, 116, '\0'   /* zTXt */
-        };
+        /* These byte strings were copied from png.h.  If a future version
+         * of readpng2.c recognizes more chunks, add them to this list.
+         */
+        static PNG_CONST png_byte chunks_to_process[] = {
+            98,  75,  71,  68, '\0',  /* bKGD */
+           103,  65,  77,  65, '\0',  /* gAMA */
+           115,  82,  71,  66, '\0',  /* sRGB */
+           };
 
-        png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
-          chunks_to_ignore, sizeof(chunks_to_ignore)/5);
+       /* Ignore all chunks except for IHDR, PLTE, tRNS, IDAT, and IEND */
+       png_set_keep_unknown_chunks(png_ptr, -1 /* PNG_HANDLE_CHUNK_NEVER */,
+          NULL, -1);
+
+       /* But do not ignore chunks in the "chunks_to_process" list */
+       png_set_keep_unknown_chunks(png_ptr,
+          0 /* PNG_HANDLE_CHUNK_AS_DEFAULT */, chunks_to_process,
+          sizeof(chunks_to_process)/5);
     }
 #endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
 

contrib/libtests/fakepng.c

@@ -0,0 +1,57 @@
+/* Fake a PNG - just write it out directly. */
+#include <stdio.h>
+#include <zlib.h> /* for crc32 */
+
+void
+put_uLong(uLong val)
+{
+   putchar(val >> 24);
+   putchar(val >> 16);
+   putchar(val >>  8);
+   putchar(val >>  0);
+}
+
+void
+put_chunk(const unsigned char *chunk, uInt length)
+{
+   uLong crc;
+
+   put_uLong(length-4); /* Exclude the tag */
+
+   fwrite(chunk, length, 1, stdout);
+
+   crc = crc32(0, Z_NULL, 0);
+   put_uLong(crc32(crc, chunk, length));
+}
+
+const unsigned char signature[] =
+{
+   137, 80, 78, 71, 13, 10, 26, 10
+};
+
+const unsigned char IHDR[] =
+{
+   73, 72, 68, 82, /* IHDR */
+   0, 0, 0, 1, /* width */
+   0, 0, 0, 1, /* height */
+   1, /* bit depth */
+   0, /* color type: greyscale */
+   0, /* compression method */
+   0, /* filter method */
+   0  /* interlace method: none */
+};
+
+const unsigned char unknown[] =
+{
+   'u', 'n', 'K', 'n' /* "unKn" - private safe to copy */
+};
+
+int
+main(void)
+{
+   fwrite(signature, sizeof signature, 1, stdout);
+   put_chunk(IHDR, sizeof IHDR);
+
+   for(;;)
+      put_chunk(unknown, sizeof unknown);
+}

contrib/libtests/gentests.sh

@@ -0,0 +1,102 @@
+#!/bin/sh
+#
+# Copyright (c) 2013 John Cunningham Bowler
+#
+# Last changed in libpng 1.6.0 [February 14, 2013]
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+#
+# Generate a set of PNG test images.  The images are generated in a
+# sub-directory called 'tests' by default, however a command line argument will
+# change that name.  The generation requires a built version of makepng in the
+# current directory.
+#
+usage(){
+   exec >&2
+   echo "$0 [<directory>]"
+   echo '  Generate a set of PNG test files in "directory" ("tests" by default)'
+   exit 1
+}
+
+mp="$PWD/makepng"
+test -x "$mp" || {
+   exec >&2
+   echo "$0: the 'makepng' program must exist"
+   echo "  in the directory within which this program:"
+   echo "    $mp"
+   echo "  is executed"
+   usage
+}
+
+# Just one argument: the directory
+testdir="tests"
+test $# -gt 1 && {
+   testdir="$1"
+   shift
+}
+test $# -eq 0 || usage
+
+# Take care not to clobber something
+if test -e "$testdir"
+then
+   test -d "$testdir" || usage
+else
+   # mkdir -p isn't portable, so do the following
+   mkdir "$testdir" 2>/dev/null || mkdir -p "$testdir" || usage
+fi
+
+# This fails in a very satisfactory way if it's not accessible
+cd "$testdir"
+:>"test$$.png" || {
+   exec >&2
+   echo "$testdir: directory not writable"
+   usage
+}
+rm "test$$.png" || {
+   exec >&2
+   echo "$testdir: you have create but not write privileges here."
+   echo "  This is unexpected.  You have a spurion; "'"'"test$$.png"'"'"."
+   echo "  You need to remove this yourself.  Try a different directory."
+   exit 1
+}
+
+# Now call makepng ($mp) to create every file we can think of with a
+# reasonable name
+doit(){
+   for gamma in "" --sRGB --linear --1.8
+   do
+      case "$gamma" in
+         "")
+            gname=;;
+         --sRGB)
+            gname="-srgb";;
+         --linear)
+            gname="-lin";;
+         --1.8)
+            gname="-18";;
+         *)
+            gname="-$gamma";;
+      esac
+      "$mp" $gamma "$1" "$2" "test-$1-$2$gname.png"
+   done
+}
+#
+for ct in gray palette
+do
+   for bd in 1 2 4 8
+   do
+      doit "$ct" "$bd"
+   done
+done
+#
+doit "gray" "16"
+#
+for ct in gray-alpha rgb rgb-alpha
+do
+   for bd in 8 16
+   do
+      doit "$ct" "$bd"
+   done
+done

contrib/libtests/pngvalid.c

@@ -1,7 +1,7 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.5.15 [March 28, 2013]
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
  * 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
@@ -3357,7 +3418,7 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
          PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
 #ifdef PNG_TEXT_SUPPORTED
-#  if defined (NG_READ_zTXt_SUPPORTED) && defined(PNG_WRITE_zTXt_SUPPORTED)
+#  if defined(PNG_READ_zTXt_SUPPORTED) && defined(PNG_WRITE_zTXt_SUPPORTED)
 #     define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_zTXt
 #  else
 #     define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_NONE
@@ -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)
@@ -4758,7 +4849,7 @@ standard_check_text(png_const_structp pp, png_const_textp tp,
 
 static void
 standard_text_validate(standard_display *dp, png_const_structp pp,
-   png_const_infop pi, int check_end)
+   png_infop pi)
 {
    png_textp tp = NULL;
    png_uint_32 num_text = png_get_text(pp, pi, &tp, NULL);
@@ -4766,13 +4857,7 @@ standard_text_validate(standard_display *dp, png_const_structp pp,
    if (num_text == 2 && tp != NULL)
    {
       standard_check_text(pp, tp, "image name", dp->ps->current->name);
-
-      /* This exists because prior to 1.6 the progressive reader left the
-       * png_struct z_stream unreset at the end of the image, so subsequent
-       * attempts to use it simply returns Z_STREAM_END.
-       */
-      if (check_end)
-         standard_check_text(pp, tp+1, "end marker", "end");
+      standard_check_text(pp, tp+1, "end marker", "end");
    }
 
    else
@@ -4785,7 +4870,7 @@ standard_text_validate(standard_display *dp, png_const_structp pp,
    }
 }
 #else
-#  define standard_text_validate(dp,pp,pi,check_end) ((void)0)
+#  define standard_text_validate(dp,pp,pi) ((void)0)
 #endif
 
 static void
@@ -4875,8 +4960,7 @@ standard_end(png_structp ppIn, png_infop pi)
    /* Validate the image - progressive reading only produces one variant for
     * interlaced images.
     */
-   standard_text_validate(dp, pp, pi,
-      PNG_LIBPNG_VER >= 10600/*check_end: see comments above*/);
+   standard_text_validate(dp, pp, pi);
    standard_image_validate(dp, pp, 0, -1);
 }
 
@@ -4947,7 +5031,7 @@ standard_test(png_store* PNG_CONST psIn, png_uint_32 PNG_CONST id,
              */
             if (!d.speed)
             {
-               standard_text_validate(&d, pp, pi, 1/*check_end*/);
+               standard_text_validate(&d, pp, pi);
                standard_image_validate(&d, pp, 0, 1);
             }
             else
@@ -5995,7 +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));
    }
 }
 
@@ -7129,7 +7213,7 @@ transform_enable(PNG_CONST char *name)
    {
       fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n",
          name);
-      exit(1);
+      exit(99);
    }
 }
 
@@ -7151,7 +7235,7 @@ transform_disable(PNG_CONST char *name)
 
    fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n",
       name);
-   exit(1);
+   exit(99);
 }
 
 static void
@@ -8699,7 +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,
@@ -9455,7 +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);
@@ -9463,7 +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);
@@ -9471,7 +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);
@@ -9479,7 +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:
@@ -9500,7 +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);
@@ -9509,7 +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);
@@ -9518,7 +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);
@@ -9527,7 +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: */
@@ -9538,7 +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);
@@ -9547,7 +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
@@ -9951,7 +10035,7 @@ int main(int argc, char **argv)
          else
          {
             fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv);
-            exit(1);
+            exit(99);
          }
 
          catmore = 1;
@@ -9963,10 +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 */
@@ -10140,12 +10265,17 @@ 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");
-   return 0;
+   fprintf(stderr,
+      "pngvalid: no low level write support in libpng, all tests skipped\n");
+   /* So the test is skipped: */
+   return 77;
 }
 #endif

contrib/libtests/readpng.c

@@ -0,0 +1,104 @@
+/* readpng.c
+ *
+ * Copyright (c) 2013 John Cunningham Bowler
+ *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Load an arbitrary number of PNG files (from the command line, or, if there
+ * are no arguments on the command line, from stdin) then run a time test by
+ * reading each file by row.  The test does nothing with the read result and
+ * does no transforms.  The only output is a time as a floating point number of
+ * seconds with 9 decimal digits.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
+#  include <config.h>
+#endif
+
+/* Define the following to use this test against your installed libpng, rather
+ * than the one being built here:
+ */
+#ifdef PNG_FREESTANDING_TESTS
+#  include <png.h>
+#else
+#  include "../../png.h"
+#endif
+
+static int
+read_png(FILE *fp)
+{
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+   png_infop info_ptr = NULL;
+   png_bytep row = NULL, display = NULL;
+
+   if (png_ptr == NULL)
+      return 0;
+
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+      if (row != NULL) free(row);
+      if (display != NULL) free(display);
+      return 0;
+   }
+
+   png_init_io(png_ptr, fp);
+
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
+      png_error(png_ptr, "OOM allocating info structure");
+
+   png_set_keep_unknown_chunks(png_ptr, PNG_HANDLE_CHUNK_ALWAYS, NULL, 0);
+
+   png_read_info(png_ptr, info_ptr);
+
+   {
+      png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+
+      row = malloc(rowbytes);
+      display = malloc(rowbytes);
+
+      if (row == NULL || display == NULL)
+         png_error(png_ptr, "OOM allocating row buffers");
+
+      {
+         png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
+         int passes = png_set_interlace_handling(png_ptr);
+         int pass;
+
+         png_start_read_image(png_ptr);
+
+         for (pass = 0; pass < passes; ++pass)
+         {
+            png_uint_32 y = height;
+
+            /* NOTE: this trashes the row each time; interlace handling won't
+             * work, but this avoids memory thrashing for speed testing.
+             */
+            while (y-- > 0)
+               png_read_row(png_ptr, row, display);
+         }
+      }
+   }
+
+   /* Make sure to read to the end of the file: */
+   png_read_end(png_ptr, info_ptr);
+   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+   free(row);
+   free(display);
+   return 1;
+}
+
+int
+main(void)
+{
+   /* Exit code 0 on success. */
+   return !read_png(stdin);
+}

contrib/libtests/tarith.c

@@ -0,0 +1,999 @@
+
+/* tarith.c
+ *
+ * Copyright (c) 2011-2013 John Cunningham Bowler
+ *
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Test internal arithmetic functions of libpng.
+ *
+ * This code must be linked against a math library (-lm), but does not require
+ * libpng or zlib to work.  Because it includes the complete source of 'png.c'
+ * it tests the code with whatever compiler options are used to build it.
+ * Changing these options can substantially change the errors in the
+ * calculations that the compiler chooses!
+ */
+#define _POSIX_SOURCE 1
+#define _ISOC99_SOURCE 1
+
+/* Obtain a copy of the code to be tested (plus other things), disabling
+ * stuff that is not required.
+ */
+#include <math.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <assert.h>
+
+#include "../../pngpriv.h"
+
+#define png_error png_warning
+
+void png_warning(png_const_structrp png_ptr, png_const_charp msg)
+{
+   fprintf(stderr, "validation: %s\n", msg);
+}
+
+#define png_fixed_error png_fixed_warning
+
+void png_fixed_warning(png_const_structrp png_ptr, png_const_charp msg)
+{
+   fprintf(stderr, "overflow in: %s\n", msg);
+}
+
+#define png_set_error_fn(pp, ep, efp, wfp) ((void)0)
+#define png_malloc(pp, s) malloc(s)
+#define png_malloc_warn(pp, s) malloc(s)
+#define png_malloc_base(pp, s) malloc(s)
+#define png_calloc(pp, s) calloc(1, (s))
+#define png_free(pp, s) free(s)
+
+#define png_safecat(b, sb, pos, str) (pos)
+#define png_format_number(start, end, format, number) (start)
+
+#define crc32(crc, pp, s) (crc)
+#define inflateReset(zs) Z_OK
+
+#define png_create_struct(type) (0)
+#define png_destroy_struct(pp) ((void)0)
+#define png_create_struct_2(type, m, mm) (0)
+#define png_destroy_struct_2(pp, f, mm) ((void)0)
+
+#undef PNG_SIMPLIFIED_READ_SUPPORTED
+#undef PNG_SIMPLIFIED_WRITE_SUPPORTED
+#undef PNG_USER_MEM_SUPPORTED
+
+#include "../../png.c"
+
+/* Validate ASCII to fp routines. */
+static int verbose = 0;
+
+int validation_ascii_to_fp(int count, int argc, char **argv)
+{
+   int    showall = 0;
+   double max_error=2;      /* As a percentage error-in-last-digit/.5 */
+   double max_error_abs=17; /* Used when precision is DBL_DIG */
+   double max = 0;
+   double max_abs = 0;
+   double test = 0; /* Important to test this. */
+   int    precision = 5;
+   int    nonfinite = 0;
+   int    finite = 0;
+   int    ok = 0;
+   int    failcount = 0;
+   int    minorarith = 0;
+
+   while (--argc > 0)
+      if (strcmp(*++argv, "-a") == 0)
+         showall = 1;
+      else if (strcmp(*argv, "-e") == 0 && argc > 0)
+      {
+         --argc;
+         max_error = atof(*++argv);
+      }
+      else if (strcmp(*argv, "-E") == 0 && argc > 0)
+      {
+         --argc;
+         max_error_abs = atof(*++argv);
+      }
+      else
+      {
+         fprintf(stderr, "unknown argument %s\n", *argv);
+         return 1;
+      }
+
+   do
+   {
+      png_size_t index;
+      int state, failed = 0;
+      char buffer[64];
+
+      if (isfinite(test))
+         ++finite;
+      else
+         ++nonfinite;
+
+      if (verbose)
+         fprintf(stderr, "%.*g %d\n", DBL_DIG, test, precision);
+
+      /* Check for overflow in the buffer by setting a marker. */
+      memset(buffer, 71, sizeof buffer);
+
+      png_ascii_from_fp(0, buffer, precision+10, test, precision);
+
+      /* Allow for a three digit exponent, this stuff will fail if
+       * the exponent is bigger than this!
+       */
+      if (buffer[precision+7] != 71)
+      {
+         fprintf(stderr, "%g[%d] -> '%s'[%lu] buffer overflow\n", test,
+            precision, buffer, (unsigned long)strlen(buffer));
+         failed = 1;
+      }
+
+      /* Following are used for the number parser below and must be
+       * initialized to zero.
+       */
+      state = 0;
+      index = 0;
+      if (!isfinite(test))
+      {
+         /* Expect 'inf' */
+         if (test >= 0 && strcmp(buffer, "inf") ||
+             test <  0 && strcmp(buffer, "-inf"))
+         {
+            fprintf(stderr, "%g[%d] -> '%s' but expected 'inf'\n", test,
+               precision, buffer);
+            failed = 1;
+         }
+      }
+      else if (!png_check_fp_number(buffer, precision+10, &state, &index) ||
+          buffer[index] != 0)
+      {
+         fprintf(stderr, "%g[%d] -> '%s' but has bad format ('%c')\n", test,
+         precision, buffer, buffer[index]);
+         failed = 1;
+      }
+      else if (PNG_FP_IS_NEGATIVE(state) && !(test < 0))
+      {
+         fprintf(stderr, "%g[%d] -> '%s' but negative value not so reported\n",
+            test, precision, buffer);
+         failed = 1;
+         assert(!PNG_FP_IS_ZERO(state));
+         assert(!PNG_FP_IS_POSITIVE(state));
+      }
+      else if (PNG_FP_IS_ZERO(state) && !(test == 0))
+      {
+         fprintf(stderr, "%g[%d] -> '%s' but zero value not so reported\n",
+            test, precision, buffer);
+         failed = 1;
+         assert(!PNG_FP_IS_NEGATIVE(state));
+         assert(!PNG_FP_IS_POSITIVE(state));
+      }
+      else if (PNG_FP_IS_POSITIVE(state) && !(test > 0))
+      {
+         fprintf(stderr, "%g[%d] -> '%s' but postive value not so reported\n",
+            test, precision, buffer);
+         failed = 1;
+         assert(!PNG_FP_IS_NEGATIVE(state));
+         assert(!PNG_FP_IS_ZERO(state));
+      }
+      else
+      {
+         /* Check the result against the original. */
+         double out = atof(buffer);
+         double change = fabs((out - test)/test);
+         double allow = .5/pow(10,
+            (precision >= DBL_DIG) ? DBL_DIG-1 : precision-1);
+
+         /* NOTE: if you hit this error case are you compiling with gcc
+          * and -O0?  Try -O2 - the errors can accumulate if the FP
+          * code above is not optimized and may drift outside the .5 in
+          * DBL_DIG allowed.  In any case a small number of errors may
+          * occur (very small ones - 1 or 2%) because of rounding in the
+          * calculations, either in the conversion API or in atof.
+          */
+         if (change >= allow && (isfinite(out) ||
+             fabs(test/DBL_MAX) <= 1-allow))
+         {
+            double percent = (precision >= DBL_DIG) ? max_error_abs : max_error;
+            double allowp = (change-allow)*100/allow;
+
+            if (precision >= DBL_DIG)
+            {
+               if (max_abs < allowp) max_abs = allowp;
+            }
+
+            else
+            {
+               if (max < allowp) max = allowp;
+            }
+
+            if (showall || allowp >= percent)
+            {
+               fprintf(stderr,
+                  "%.*g[%d] -> '%s' -> %.*g number changed (%g > %g (%d%%))\n",
+                  DBL_DIG, test, precision, buffer, DBL_DIG, out, change, allow,
+                  (int)round(allowp));
+               failed = 1;
+            }
+            else
+               ++minorarith;
+         }
+      }
+
+      if (failed)
+         ++failcount;
+      else
+         ++ok;
+
+skip:
+      /* Generate a new number and precision. */
+      precision = rand();
+      if (precision & 1) test = -test;
+      precision >>= 1;
+
+      /* Generate random numbers. */
+      if (test == 0 || !isfinite(test))
+         test = precision+1;
+      else
+      {
+         /* Derive the exponent from the previous rand() value. */
+         int exponent = precision % (DBL_MAX_EXP - DBL_MIN_EXP) + DBL_MIN_EXP;
+         int tmp;
+         test = frexp(test * rand(), &tmp);
+         test = ldexp(test, exponent);
+         precision >>= 8; /* arbitrary */
+      }
+
+      /* This limits the precision to 32 digits, enough for standard
+       * IEEE implementations which have at most 15 digits.
+       */
+      precision = (precision & 0x1f) + 1;
+   }
+   while (--count);
+
+   printf("Tested %d finite values, %d non-finite, %d OK (%d failed) %d minor "
+      "arithmetic errors\n", finite, nonfinite, ok, failcount, minorarith);
+   printf(" Error with >=%d digit precision %.2f%%\n", DBL_DIG, max_abs);
+   printf(" Error with < %d digit precision %.2f%%\n", DBL_DIG, max);
+
+   return 0;
+}
+
+/* Observe that valid FP numbers have the forms listed in the PNG extensions
+ * specification:
+ *
+ * [+,-]{integer,integer.fraction,.fraction}[{e,E}[+,-]integer]
+ *
+ * Test each of these in turn, including invalid cases.
+ */
+typedef enum checkfp_state
+{
+   start, fraction, exponent, states
+} checkfp_state;
+
+/* The characters (other than digits) that characterize the states: */
+static const char none[] = "";
+static const char hexdigits[16] = "0123456789ABCDEF";
+
+static const struct
+{
+   const char *start; /* Characters valid at the start */
+   const char *end;   /* Valid characters that end the state */
+   const char *tests; /* Characters to test after 2 digits seen */
+}
+state_characters[states] =
+{
+   /* start:    */ { "+-.", ".eE", "+-.e*0369" },
+   /* fraction: */ { none, "eE",  "+-.E#0147" },
+   /* exponent: */ { "+-", none,  "+-.eE^0258" }
+};
+
+typedef struct
+{
+   char number[1024];  /* Buffer for number being tested */
+   int  limit;         /* Command line limit */
+   int  verbose;       /* Shadows global variable */
+   int  ctimes;        /* Number of numbers tested */
+   int  cmillions;     /* Count of millions of numbers */
+   int  cinvalid;      /* Invalid strings checked */
+   int  cnoaccept;     /* Characters not accepted */
+}
+checkfp_command;
+
+typedef struct
+{
+   int           cnumber;          /* Index into number string */
+   checkfp_state check_state;      /* Current number state */
+   int           at_start;         /* At start (first character) of state */
+   int           cdigits_in_state; /* Digits seen in that state */
+   int           limit;            /* Limit on same for checking all chars */
+   int           state;            /* Current parser state */
+   int           is_negative;      /* Number is negative */
+   int           is_zero;          /* Number is (still) zero */
+   int           number_was_valid; /* Previous character validity */
+}
+checkfp_control;
+
+static int check_all_characters(checkfp_command *co, checkfp_control c);
+
+static int check_some_characters(checkfp_command *co, checkfp_control c,
+   const char *tests);
+
+static int check_one_character(checkfp_command *co, checkfp_control c, int ch)
+{
+   /* Test this character (ch) to ensure the parser does the correct thing.
+    */
+   png_size_t index = 0;
+   const char test = (char)ch;
+   const int number_is_valid = png_check_fp_number(&test, 1, &c.state, &index);
+   const int character_accepted = (index == 1);
+
+   if (c.check_state != exponent && isdigit(ch) && ch != '0')
+      c.is_zero = 0;
+
+   if (c.check_state == start && c.at_start && ch == '-')
+      c.is_negative = 1;
+
+   if (isprint(ch))
+      co->number[c.cnumber++] = (char)ch;
+   else
+   {
+      co->number[c.cnumber++] = '<';
+      co->number[c.cnumber++] = hexdigits[(ch >> 4) & 0xf];
+      co->number[c.cnumber++] = hexdigits[ch & 0xf];
+      co->number[c.cnumber++] = '>';
+   }
+   co->number[c.cnumber] = 0;
+
+   if (co->verbose > 1)
+      fprintf(stderr, "%s\n", co->number);
+
+   if (++(co->ctimes) == 1000000)
+   {
+      if (co->verbose == 1)
+         fputc('.', stderr);
+      co->ctimes = 0;
+      ++(co->cmillions);
+   }
+
+   if (!number_is_valid)
+      ++(co->cinvalid);
+
+   if (!character_accepted)
+      ++(co->cnoaccept);
+
+   /* This should never fail (it's a serious bug if it does): */
+   if (index != 0 && index != 1)
+   {
+      fprintf(stderr, "%s: read beyond end of string (%lu)\n", co->number,
+         (unsigned long)index);
+      return 0;
+   }
+
+   /* Validate the new state, note that the PNG_FP_IS_ macros all return
+    * false unless the number is valid.
+    */
+   if (PNG_FP_IS_NEGATIVE(c.state) !=
+      (number_is_valid && !c.is_zero && c.is_negative))
+   {
+      fprintf(stderr, "%s: negative when it is not\n", co->number);
+      return 0;
+   }
+
+   if (PNG_FP_IS_ZERO(c.state) != (number_is_valid && c.is_zero))
+   {
+      fprintf(stderr, "%s: zero when it is not\n", co->number);
+      return 0;
+   }
+
+   if (PNG_FP_IS_POSITIVE(c.state) !=
+      (number_is_valid && !c.is_zero && !c.is_negative))
+   {
+      fprintf(stderr, "%s: positive when it is not\n", co->number);
+      return 0;
+   }
+
+   /* Testing a digit */
+   if (isdigit(ch))
+   {
+      if (!character_accepted)
+      {
+         fprintf(stderr, "%s: digit '%c' not accepted\n", co->number, ch);
+         return 0;
+      }
+
+      if (!number_is_valid)
+      {
+         fprintf(stderr, "%s: saw a digit (%c) but number not valid\n",
+            co->number, ch);
+         return 0;
+      }
+
+      ++c.cdigits_in_state;
+      c.at_start = 0;
+      c.number_was_valid = 1;
+
+      /* Continue testing characters in this state.  Either test all of
+       * them or, if we have already seen one digit in this state, just test a
+       * limited set.
+       */
+      if (c.cdigits_in_state < 1)
+         return check_all_characters(co, c);
+
+      else
+         return check_some_characters(co, c,
+            state_characters[c.check_state].tests);
+   }
+
+   /* A non-digit; is it allowed here? */
+   else if (((ch == '+' || ch == '-') && c.check_state != fraction &&
+               c.at_start) ||
+            (ch == '.' && c.check_state == start) ||
+            ((ch == 'e' || ch == 'E') && c.number_was_valid &&
+               c.check_state != exponent))
+   {
+      if (!character_accepted)
+      {
+         fprintf(stderr, "%s: character '%c' not accepted\n", co->number, ch);
+         return 0;
+      }
+
+      /* The number remains valid after start of fraction but nowhere else. */
+      if (number_is_valid && (c.check_state != start || ch != '.'))
+      {
+         fprintf(stderr, "%s: saw a non-digit (%c) but number valid\n",
+            co->number, ch);
+         return 0;
+      }
+
+      c.number_was_valid = number_is_valid;
+
+      /* Check for a state change.  When changing to 'fraction' if the number
+       * is valid at this point set the at_start to false to allow an exponent
+       * 'e' to come next.
+       */
+      if (c.check_state == start && ch == '.')
+      {
+         c.check_state = fraction;
+         c.at_start = !number_is_valid;
+         c.cdigits_in_state = 0;
+         c.limit = co->limit;
+         return check_all_characters(co, c);
+      }
+
+      else if (c.check_state < exponent && (ch == 'e' || ch == 'E'))
+      {
+         c.check_state = exponent;
+         c.at_start = 1;
+         c.cdigits_in_state = 0;
+         c.limit = co->limit;
+         return check_all_characters(co, c);
+      }
+
+      /* Else it was a sign, and the state doesn't change. */
+      else
+      {
+         if (ch != '-' && ch != '+')
+         {
+            fprintf(stderr, "checkfp: internal error (1)\n");
+            return 0;
+         }
+
+         c.at_start = 0;
+         return check_all_characters(co, c);
+      }
+   }
+
+   /* Testing an invalid character */
+   else
+   {
+      if (character_accepted)
+      {
+         fprintf(stderr, "%s: character '%c' [0x%.2x] accepted\n", co->number,
+            ch, ch);
+         return 0;
+      }
+
+      if (number_is_valid != c.number_was_valid)
+      {
+         fprintf(stderr,
+            "%s: character '%c' [0x%.2x] changed number validity\n", co->number,
+            ch, ch);
+         return 0;
+      }
+
+      /* Do nothing - the parser has stuck; return success and keep going with
+       * the next character.
+       */
+   }
+
+   /* Successful return (the caller will try the next character.) */
+   return 1;
+}
+
+static int check_all_characters(checkfp_command *co, checkfp_control c)
+{
+   int ch;
+
+   if (c.cnumber+4 < sizeof co->number) for (ch=0; ch<256; ++ch)
+   {
+      if (!check_one_character(co, c, ch))
+         return 0;
+   }
+
+   return 1;
+}
+
+static int check_some_characters(checkfp_command *co, checkfp_control c,
+   const char *tests)
+{
+   int i;
+
+   --(c.limit);
+
+   if (c.cnumber+4 < sizeof co->number && c.limit >= 0)
+   {
+      if (c.limit > 0) for (i=0; tests[i]; ++i)
+      {
+         if (!check_one_character(co, c, tests[i]))
+               return 0;
+      }
+
+      /* At the end check all the characters. */
+      else
+         return check_all_characters(co, c);
+   }
+
+   return 1;
+}
+
+int validation_checkfp(int count, int argc, char **argv)
+{
+   int result;
+   checkfp_command command;
+   checkfp_control control;
+
+   command.number[0] = 0;
+   command.limit = 3;
+   command.verbose = verbose;
+   command.ctimes = 0;
+   command.cmillions = 0;
+   command.cinvalid = 0;
+   command.cnoaccept = 0;
+
+   while (--argc > 0)
+   {
+      ++argv;
+      if (argc > 1 && strcmp(*argv, "-l") == 0)
+      {
+         --argc;
+         command.limit = atoi(*++argv);
+      }
+
+      else
+      {
+         fprintf(stderr, "unknown argument %s\n", *argv);
+         return 1;
+      }
+   }
+
+   control.cnumber = 0;
+   control.check_state = start;
+   control.at_start = 1;
+   control.cdigits_in_state = 0;
+   control.limit = command.limit;
+   control.state = 0;
+   control.is_negative = 0;
+   control.is_zero = 1;
+   control.number_was_valid = 0;
+
+   result = check_all_characters(&command, control);
+
+   printf("checkfp: %s: checked %d,%.3d,%.3d,%.3d strings (%d invalid)\n",
+      result ? "pass" : "FAIL", command.cmillions / 1000,
+      command.cmillions % 1000, command.ctimes / 1000, command.ctimes % 1000,
+      command.cinvalid);
+
+   return result;
+}
+
+int validation_muldiv(int count, int argc, char **argv)
+{
+   int tested = 0;
+   int overflow = 0;
+   int error = 0;
+   int error64 = 0;
+   int passed = 0;
+   int randbits = 0;
+   png_uint_32 randbuffer;
+   png_fixed_point a;
+   png_int_32 times, div;
+
+   while (--argc > 0)
+      {
+         fprintf(stderr, "unknown argument %s\n", *++argv);
+         return 1;
+      }
+
+   /* Find out about the random number generator. */
+   randbuffer = RAND_MAX;
+   while (randbuffer != 0) ++randbits, randbuffer >>= 1;
+   printf("Using random number generator that makes %d bits\n", randbits);
+   for (div=0; div<32; div += randbits)
+      randbuffer = (randbuffer << randbits) ^ rand();
+
+   a = 0;
+   times = div = 0;
+   do
+   {
+      png_fixed_point result;
+      /* NOTE: your mileage may vary, a type is required below that can
+       * hold 64 bits or more, if floating point is used a 64 bit or
+       * better mantissa is required.
+       */
+      long long int fp, fpround;
+      unsigned long hi, lo;
+      int ok;
+
+      /* Check the values, png_64bit_product can only handle positive
+       * numbers, so correct for that here.
+       */
+      {
+         long u1, u2;
+         int n = 0;
+         if (a < 0) u1 = -a, n = 1; else u1 = a;
+         if (times < 0) u2 = -times, n = !n; else u2 = times;
+         png_64bit_product(u1, u2, &hi, &lo);
+         if (n)
+         {
+            /* -x = ~x+1 */
+            lo = ((~lo) + 1) & 0xffffffff;
+            hi = ~hi;
+            if (lo == 0) ++hi;
+         }
+      }
+
+      fp = a;
+      fp *= times;
+      if ((fp & 0xffffffff) != lo || ((fp >> 32) & 0xffffffff) != hi)
+      {
+         fprintf(stderr, "png_64bit_product %d * %d -> %lx|%.8lx not %llx\n",
+            a, times, hi, lo, fp);
+         ++error64;
+      }
+
+      if (div != 0)
+      {
+         /* Round - this is C round to zero. */
+         if ((fp < 0) != (div < 0))
+           fp -= div/2;
+         else
+           fp += div/2;
+
+         fp /= div;
+         fpround = fp;
+         /* Assume 2's complement here: */
+         ok = fpround <= PNG_UINT_31_MAX &&
+              fpround >= -1-(long long int)PNG_UINT_31_MAX;
+         if (!ok) ++overflow;
+      }
+      else
+        ok = 0, ++overflow, fpround = fp/*misleading*/;
+
+      if (verbose)
+         fprintf(stderr, "TEST %d * %d / %d -> %lld (%s)\n", a, times, div,
+            fp, ok ? "ok" : "overflow");
+
+      ++tested;
+      if (png_muldiv(&result, a, times, div) != ok)
+      {
+         ++error;
+         if (ok)
+             fprintf(stderr, "%d * %d / %d -> overflow (expected %lld)\n", a,
+                times, div, fp);
+         else
+             fprintf(stderr, "%d * %d / %d -> %d (expected overflow %lld)\n", a,
+                times, div, result, fp);
+      }
+      else if (ok && result != fpround)
+      {
+         ++error;
+         fprintf(stderr, "%d * %d / %d -> %d not %lld\n", a, times, div, result,
+            fp);
+      }
+      else
+         ++passed;
+
+      /* Generate three new values, this uses rand() and rand() only returns
+       * up to RAND_MAX.
+       */
+      /* CRUDE */
+      a += times;
+      times += div;
+      div = randbuffer;
+      randbuffer = (randbuffer << randbits) ^ rand();
+   }
+   while (--count > 0);
+
+   printf("%d tests including %d overflows, %d passed, %d failed (%d 64 bit "
+      "errors)\n", tested, overflow, passed, error, error64);
+   return 0;
+}
+
+/* When FP is on this just becomes a speed test - compile without FP to get real
+ * validation.
+ */
+#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+#define LN2 .000010576586617430806112933839 /* log(2)/65536 */
+#define L2INV 94548.46219969910586572651    /* 65536/log(2) */
+
+/* For speed testing, need the internal functions too: */
+static png_uint_32 png_log8bit(unsigned x)
+{
+   if (x > 0)
+      return (png_uint_32)floor(.5-log(x/255.)*L2INV);
+
+   return 0xffffffff;
+}
+
+static png_uint_32 png_log16bit(png_uint_32 x)
+{
+   if (x > 0)
+      return (png_uint_32)floor(.5-log(x/65535.)*L2INV);
+
+   return 0xffffffff;
+}
+
+static png_uint_32 png_exp(png_uint_32 x)
+{
+   return (png_uint_32)floor(.5 + exp(x * -LN2) * 0xffffffffU);
+}
+
+static png_byte png_exp8bit(png_uint_32 log)
+{
+   return (png_byte)floor(.5 + exp(log * -LN2) * 255);
+}
+
+static png_uint_16 png_exp16bit(png_uint_32 log)
+{
+   return (png_uint_16)floor(.5 + exp(log * -LN2) * 65535);
+}
+#endif /* FLOATING_ARITHMETIC */
+
+int validation_gamma(int argc, char **argv)
+{
+   double gamma[9] = { 2.2, 1.8, 1.52, 1.45, 1., 1/1.45, 1/1.52, 1/1.8, 1/2.2 };
+   double maxerr;
+   int i, silent=0, onlygamma=0;
+
+   /* Silence the output with -s, just test the gamma functions with -g: */
+   while (--argc > 0)
+      if (strcmp(*++argv, "-s") == 0)
+         silent = 1;
+      else if (strcmp(*argv, "-g") == 0)
+         onlygamma = 1;
+      else
+      {
+         fprintf(stderr, "unknown argument %s\n", *argv);
+         return 1;
+      }
+
+   if (!onlygamma)
+   {
+      /* First validate the log functions: */
+      maxerr = 0;
+      for (i=0; i<256; ++i)
+      {
+         double correct = -log(i/255.)/log(2.)*65536;
+         double error = png_log8bit(i) - correct;
+
+         if (i != 0 && fabs(error) > maxerr)
+            maxerr = fabs(error);
+
+         if (i == 0 && png_log8bit(i) != 0xffffffff ||
+             i != 0 && png_log8bit(i) != floor(correct+.5))
+         {
+            fprintf(stderr, "8 bit log error: %d: got %u, expected %f\n",
+               i, png_log8bit(i), correct);
+         }
+      }
+
+      if (!silent)
+         printf("maximum 8 bit log error = %f\n", maxerr);
+
+      maxerr = 0;
+      for (i=0; i<65536; ++i)
+      {
+         double correct = -log(i/65535.)/log(2.)*65536;
+         double error = png_log16bit(i) - correct;
+
+         if (i != 0 && fabs(error) > maxerr)
+            maxerr = fabs(error);
+
+         if (i == 0 && png_log16bit(i) != 0xffffffff ||
+             i != 0 && png_log16bit(i) != floor(correct+.5))
+         {
+            if (error > .68) /* By experiment error is less than .68 */
+            {
+               fprintf(stderr, "16 bit log error: %d: got %u, expected %f"
+                  " error: %f\n", i, png_log16bit(i), correct, error);
+            }
+         }
+      }
+
+      if (!silent)
+         printf("maximum 16 bit log error = %f\n", maxerr);
+
+      /* Now exponentiations. */
+      maxerr = 0;
+      for (i=0; i<=0xfffff; ++i)
+      {
+         double correct = exp(-i/65536. * log(2.)) * (65536. * 65536);
+         double error = png_exp(i) - correct;
+
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (fabs(error) > 1883) /* By experiment. */
+         {
+            fprintf(stderr, "32 bit exp error: %d: got %u, expected %f"
+                  " error: %f\n", i, png_exp(i), correct, error);
+         }
+      }
+
+      if (!silent)
+         printf("maximum 32 bit exp error = %f\n", maxerr);
+
+      maxerr = 0;
+      for (i=0; i<=0xfffff; ++i)
+      {
+         double correct = exp(-i/65536. * log(2.)) * 255;
+         double error = png_exp8bit(i) - correct;
+
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (fabs(error) > .50002) /* By experiment */
+         {
+            fprintf(stderr, "8 bit exp error: %d: got %u, expected %f"
+                  " error: %f\n", i, png_exp8bit(i), correct, error);
+         }
+      }
+
+      if (!silent)
+         printf("maximum 8 bit exp error = %f\n", maxerr);
+
+      maxerr = 0;
+      for (i=0; i<=0xfffff; ++i)
+      {
+         double correct = exp(-i/65536. * log(2.)) * 65535;
+         double error = png_exp16bit(i) - correct;
+
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (fabs(error) > .524) /* By experiment */
+         {
+            fprintf(stderr, "16 bit exp error: %d: got %u, expected %f"
+                  " error: %f\n", i, png_exp16bit(i), correct, error);
+         }
+      }
+
+      if (!silent)
+         printf("maximum 16 bit exp error = %f\n", maxerr);
+   } /* !onlygamma */
+
+   /* Test the overall gamma correction. */
+   for (i=0; i<9; ++i)
+   {
+      unsigned j;
+      double g = gamma[i];
+      png_fixed_point gfp = floor(g * PNG_FP_1 + .5);
+
+      if (!silent)
+         printf("Test gamma %f\n", g);
+
+      maxerr = 0;
+      for (j=0; j<256; ++j)
+      {
+         double correct = pow(j/255., g) * 255;
+         png_byte out = png_gamma_8bit_correct(j, gfp);
+         double error = out - correct;
+
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (out != floor(correct+.5))
+         {
+            fprintf(stderr, "8bit %d ^ %f: got %d expected %f error %f\n",
+               j, g, out, correct, error);
+         }
+      }
+
+      if (!silent)
+         printf("gamma %f: maximum 8 bit error %f\n", g, maxerr);
+
+      maxerr = 0;
+      for (j=0; j<65536; ++j)
+      {
+         double correct = pow(j/65535., g) * 65535;
+         png_uint_16 out = png_gamma_16bit_correct(j, gfp);
+         double error = out - correct;
+
+         if (fabs(error) > maxerr)
+            maxerr = fabs(error);
+         if (fabs(error) > 1.62)
+         {
+            fprintf(stderr, "16bit %d ^ %f: got %d expected %f error %f\n",
+               j, g, out, correct, error);
+         }
+      }
+
+      if (!silent)
+         printf("gamma %f: maximum 16 bit error %f\n", g, maxerr);
+   }
+
+   return 0;
+}
+
+/**************************** VALIDATION TESTS ********************************/
+/* Various validation routines are included herein, they require some
+ * definition for png_warning and png_error, seetings of VALIDATION:
+ *
+ * 1: validates the ASCII to floating point conversions
+ * 2: validates png_muldiv
+ * 3: accuracy test of fixed point gamma tables
+ */
+
+/* The following COUNT (10^8) takes about 1 hour on a 1GHz Pentium IV
+ * processor.
+ */
+#define COUNT 1000000000
+
+int main(int argc, char **argv)
+{
+   int count = COUNT;
+
+   while (argc > 1)
+   {
+      if (argc > 2 && strcmp(argv[1], "-c") == 0)
+      {
+         count = atoi(argv[2]);
+         argc -= 2;
+         argv += 2;
+      }
+
+      else if (strcmp(argv[1], "-v") == 0)
+      {
+         ++verbose;
+         --argc;
+         ++argv;
+      }
+
+      else
+         break;
+   }
+
+   if (count > 0 && argc > 1)
+   {
+      if (strcmp(argv[1], "ascii") == 0)
+         return validation_ascii_to_fp(count, argc-1, argv+1);
+      else if (strcmp(argv[1], "checkfp") == 0)
+         return validation_checkfp(count, argc-1, argv+1);
+      else if (strcmp(argv[1], "muldiv") == 0)
+         return validation_muldiv(count, argc-1, argv+1);
+      else if (strcmp(argv[1], "gamma") == 0)
+         return validation_gamma(argc-1, argv+1);
+   }
+
+   /* Bad argument: */
+   fprintf(stderr,
+      "usage: tarith [-v] [-c count] {ascii,muldiv,gamma} [args]\n");
+   fprintf(stderr, " arguments: ascii [-a (all results)] [-e error%%]\n");
+   fprintf(stderr, "            checkfp [-l max-number-chars]\n");
+   fprintf(stderr, "            muldiv\n");
+   fprintf(stderr, "            gamma -s (silent) -g (only gamma; no log)\n");
+   return 1;
+}

contrib/libtests/timepng.c

@@ -0,0 +1,303 @@
+/* timepng.c
+ *
+ * Copyright (c) 2013 John Cunningham Bowler
+ *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Load an arbitrary number of PNG files (from the command line, or, if there
+ * are no arguments on the command line, from stdin) then run a time test by
+ * reading each file by row.  The test does nothing with the read result and
+ * does no transforms.  The only output is a time as a floating point number of
+ * seconds with 9 decimal digits.
+ */
+#define _POSIX_C_SOURCE 199309L /* for clock_gettime */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <time.h>
+
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
+#  include <config.h>
+#endif
+
+/* Define the following to use this test against your installed libpng, rather
+ * than the one being built here:
+ */
+#ifdef PNG_FREESTANDING_TESTS
+#  include <png.h>
+#else
+#  include "../../png.h"
+#endif
+
+static int read_png(FILE *fp)
+{
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+   png_infop info_ptr = NULL;
+   png_bytep row = NULL, display = NULL;
+
+   if (png_ptr == NULL)
+      return 0;
+
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+      if (row != NULL) free(row);
+      if (display != NULL) free(display);
+      return 0;
+   }
+
+   png_init_io(png_ptr, fp);
+
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
+      png_error(png_ptr, "OOM allocating info structure");
+
+   png_read_info(png_ptr, info_ptr);
+
+   {
+      png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+
+      row = malloc(rowbytes);
+      display = malloc(rowbytes);
+
+      if (row == NULL || display == NULL)
+         png_error(png_ptr, "OOM allocating row buffers");
+
+      {
+         png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
+         int passes = png_set_interlace_handling(png_ptr);
+         int pass;
+
+         png_start_read_image(png_ptr);
+
+         for (pass = 0; pass < passes; ++pass)
+         {
+            png_uint_32 y = height;
+
+            /* NOTE: this trashes the row each time; interlace handling won't
+             * work, but this avoids memory thrashing for speed testing.
+             */
+            while (y-- > 0)
+               png_read_row(png_ptr, row, display);
+         }
+      }
+   }
+
+   /* Make sure to read to the end of the file: */
+   png_read_end(png_ptr, info_ptr);
+   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+   free(row);
+   free(display);
+   return 1;
+}
+
+static int mytime(struct timespec *t)
+{
+   /* Do the timing using clock_gettime and the per-process timer. */
+   if (!clock_gettime(CLOCK_PROCESS_CPUTIME_ID, t))
+      return 1;
+
+   perror("CLOCK_PROCESS_CPUTIME_ID");
+   fprintf(stderr, "timepng: could not get the time\n");
+   return 0;
+}
+
+static int perform_one_test(FILE *fp, int nfiles)
+{
+   int i;
+   struct timespec before, after;
+
+   /* Clear out all errors: */
+   rewind(fp);
+
+   if (mytime(&before))
+   {
+      for (i=0; i<nfiles; ++i)
+      {
+         if (read_png(fp))
+         {
+            if (ferror(fp))
+            {
+               perror("temporary file");
+               fprintf(stderr, "file %d: error reading PNG data\n", i);
+               return 0;
+            }
+         }
+
+         else
+         {
+            perror("temporary file");
+            fprintf(stderr, "file %d: error from libpng\n", i);
+            return 0;
+         }
+      }
+   }
+
+   else
+      return 0;
+
+   if (mytime(&after))
+   {
+      /* Work out the time difference and print it - this is the only output,
+       * so flush it immediately.
+       */
+      unsigned long s = after.tv_sec - before.tv_sec;
+      long ns = after.tv_nsec - before.tv_nsec;
+
+      if (ns < 0)
+      {
+         --s;
+         ns += 1000000000;
+
+         if (ns < 0)
+         {
+            fprintf(stderr, "timepng: bad clock from kernel\n");
+            return 0;
+         }
+      }
+
+      printf("%lu.%.9ld\n", s, ns);
+      fflush(stdout);
+      if (ferror(stdout))
+      {
+         fprintf(stderr, "timepng: error writing output\n");
+         return 0;
+      }
+
+      /* Successful return */
+      return 1;
+   }
+
+   else
+      return 0;
+}
+
+static int add_one_file(FILE *fp, char *name)
+{
+   FILE *ip = fopen(name, "rb");
+
+   if (ip != NULL)
+   {
+      int ch;
+      for (;;)
+      {
+         ch = getc(ip);
+         if (ch == EOF) break;
+         putc(ch, fp);
+      }
+
+      if (ferror(ip))
+      {
+         perror(name);
+         fprintf(stderr, "%s: read error\n", name);
+         return 0;
+      }
+
+      (void)fclose(ip);
+
+      if (ferror(fp))
+      {
+         perror("temporary file");
+         fprintf(stderr, "temporary file write error\n");
+         return 0;
+      }
+   }
+
+   else
+   {
+      perror(name);
+      fprintf(stderr, "%s: open failed\n", name);
+      return 0;
+   }
+
+   return 1;
+}
+
+int main(int argc, char **argv)
+{
+   int ok = 0;
+   FILE *fp = tmpfile();
+
+   if (fp != NULL)
+   {
+      int err = 0;
+      int nfiles = 0;
+
+      if (argc > 1)
+      {
+         int i;
+
+         for (i=1; i<argc; ++i)
+         {
+            if (add_one_file(fp, argv[i]))
+               ++nfiles;
+
+            else
+            {
+               err = 1;
+               break;
+            }
+         }
+      }
+
+      else
+      {
+         char filename[FILENAME_MAX+1];
+
+         while (fgets(filename, FILENAME_MAX+1, stdin))
+         {
+            size_t len = strlen(filename);
+
+            if (filename[len-1] == '\n')
+            {
+               filename[len-1] = 0;
+               if (add_one_file(fp, filename))
+                  ++nfiles;
+
+               else
+               {
+                  err = 1;
+                  break;
+               }
+            }
+
+            else
+            {
+               fprintf(stderr, "timepng: truncated file name ...%s\n",
+                  filename+len-32);
+               err = 1;
+               break;
+            }
+         }
+
+         if (ferror(stdin))
+         {
+            fprintf(stderr, "timepng: stdin: read error\n");
+            err = 1;
+         }
+      }
+
+      if (!err)
+      {
+         if (nfiles > 0)
+            ok = perform_one_test(fp, nfiles);
+
+         else
+            fprintf(stderr, "usage: timepng {files} or ls files | timepng\n");
+      }
+
+      (void)fclose(fp);
+   }
+
+   else
+      fprintf(stderr, "timepng: could not open temporary file\n");
+
+   /* Exit code 0 on success. */
+   return ok == 0;
+}

contrib/pngminim/README

@@ -1,3 +1,4 @@
+
 This demonstrates the use of PNG_USER_CONFIG, pngusr.h and pngusr.dfa
 to build minimal decoder, encoder, and progressive reader applications.
 

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/decoder/pngusr.dfa

@@ -1,6 +1,6 @@
 # pngminim/decoder/pngusr.dfa
 #
-# Copyright (c) 2010-2011 Glenn Randers-Pehrson
+# Copyright (c) 2010-2013 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -37,3 +37,4 @@ option SETJMP on
 option STDIO on
 option READ_EXPAND on
 option READ_STRIP_16_TO_8 on
+option USER_LIMITS on

contrib/pngminim/decoder/pngusr.h

@@ -1,6 +1,6 @@
 /* minrdpngconf.h: headers to make a minimal png-read-only library
  *
- * Copyright (c) 2007, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2007, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

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/encoder/pngusr.h

@@ -1,6 +1,6 @@
 /* minwrpngconf.h: headers to make a minimal png-write-only library
  *
- * Copyright (c) 2007, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2007, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

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/pngminim/preader/pngusr.dfa

@@ -1,6 +1,6 @@
 # pngminim/preader/pngusr.dfa
 #
-# Copyright (c) 2010-2011 Glenn Randers-Pehrson
+# Copyright (c) 2010-2013 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer

contrib/pngminim/preader/pngusr.h

@@ -1,6 +1,6 @@
 /* minrdpngconf.h: headers to make a minimal png-read-only library
  *
- * Copyright (c) 2009, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2009, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

contrib/pngminus/makefile.std

@@ -8,9 +8,9 @@ LD=$(CC)
 RM=rm -f
 
 #PNGPATH = /usr/local
-#PNGINC = -I$(PNGPATH)/include/libpng15
-#PNGLIB = -L$(PNGPATH)/lib -lpng15
-#PNGLIBS = $(PNGPATH)/lib/libpng15.a
+#PNGINC = -I$(PNGPATH)/include/libpng16
+#PNGLIB = -L$(PNGPATH)/lib -lpng16
+#PNGLIBS = $(PNGPATH)/lib/libpng16.a
 PNGINC = -I../..
 PNGLIB = -L../.. -lpng
 PNGLIBS = ../../libpng.a

contrib/pngminus/png2pnm.c

@@ -18,6 +18,7 @@
 #include <mem.h>
 #include <fcntl.h>
 #endif
+#include <zlib.h>
 
 #ifndef BOOL
 #define BOOL unsigned char

contrib/tools/README.txt

@@ -0,0 +1,26 @@
+This directory (contrib/tools) contains tools used by the authors of libpng.
+
+Code and data placed in this directory is not required to build libpng,
+however the code in this directory has been used to generate data or code in
+the body of the libpng source.  The source code identifies where this has
+been done.  Code in this directory may not compile on all operating systems
+that libpng supports.
+
+NO COPYRIGHT RIGHTS ARE CLAIMED TO ANY OF THE FILES IN THIS DIRECTORY.
+
+To the extent possible under law, the authors have waived all copyright and
+related or neighboring rights to this work.  This work is published from:
+United States.
+
+The files may be used freely in any way.
+
+The source code and comments in this directory are the original work of the
+people named below.  No other person or organization has made contributions to
+the work in this directory.
+
+ORIGINAL AUTHORS
+    The following people have contributed to the code in this directory.  None
+    of the people below claim any rights with regard to the contents of this
+    directory.
+
+    John Bowler <jbowler@acm.org>

contrib/tools/checksum-icc.c

@@ -0,0 +1,102 @@
+/* checksum-icc.c
+ *
+ * Copyright (c) 2013 John Cunningham Bowler
+ *
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Generate crc32 and adler32 checksums of the given input files, used to
+ * generate check-codes for use when matching ICC profiles within libpng.
+ */
+#include <stdio.h>
+
+#include <zlib.h>
+
+static int
+read_one_file(FILE *ip, const char *name)
+{
+   uLong length = 0;
+   uLong a32 = adler32(0, NULL, 0);
+   uLong c32 = crc32(0, NULL, 0);
+   Byte header[132];
+
+   for (;;)
+   {
+      int ch = getc(ip);
+      Byte b;
+
+      if (ch == EOF) break;
+
+      b = (Byte)ch;
+
+      if (length < sizeof header)
+         header[length] = b;
+
+      ++length;
+      a32 = adler32(a32, &b, 1);
+      c32 = crc32(c32, &b, 1);
+   }
+
+   if (ferror(ip))
+      return 0;
+
+   /* Success */
+   printf("PNG_ICC_CHECKSUM(0x%8.8lx, 0x%8.8lx,\n   PNG_MD5("
+      "0x%2.2x%2.2x%2.2x%2.2x, 0x%2.2x%2.2x%2.2x%2.2x, 0x%2.2x%2.2x%2.2x%2.2x,"
+      " 0x%2.2x%2.2x%2.2x%2.2x), %d,\n"
+      "   \"%4.4d/%2.2d/%2.2d %2.2d:%2.2d:%2.2d\", %lu, \"%s\")\n",
+      (unsigned long)a32, (unsigned long)c32,
+      header[84], header[85], header[86], header[87],
+      header[88], header[89], header[90], header[91],
+      header[92], header[93], header[94], header[95],
+      header[96], header[97], header[98], header[99],
+#     define u16(x) (header[x] * 256 + header[x+1])
+#     define u32(x) (u16(x) * 65536 + u16(x+2))
+      u32(64), u16(24), u16(26), u16(28), u16(30), u16(32), u16(34),
+      (unsigned long)length, name);
+
+   return 1;
+}
+
+int main(int argc, char **argv)
+{
+   int err = 0;
+
+   printf("/* adler32, crc32, MD5[16], intent, date, length, file-name */\n");
+
+   if (argc > 1)
+   {
+      int i;
+
+      for (i=1; i<argc; ++i)
+      {
+         FILE *ip = fopen(argv[i], "rb");
+
+         if (ip == NULL || !read_one_file(ip, argv[i]))
+         {
+            err = 1;
+            perror(argv[i]);
+            fprintf(stderr, "%s: read error\n", argv[i]);
+            printf("/* ERROR: %s */\n", argv[i]);
+         }
+
+         (void)fclose(ip);
+      }
+   }
+
+   else
+   {
+      if (!read_one_file(stdin, "-"))
+      {
+         err = 1;
+         perror("stdin");
+         fprintf(stderr, "stdin: read error\n");
+         printf("/* ERROR: stdin */\n");
+      }
+   }
+
+   return err;
+}

contrib/tools/cvtcolor.c

@@ -0,0 +1,188 @@
+/*-
+ * convert.c
+ *
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2013.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Convert 8-bit sRGB or 16-bit linear values to another format.
+ */
+#define _ISOC99_SOURCE 1
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <stdio.h>
+
+#include <fenv.h>
+
+#include "sRGB.h"
+
+static void
+usage(const char *prog)
+{
+   fprintf(stderr,
+      "%s: usage: %s [-linear|-sRGB] [-gray|-color] component{1,4}\n",
+      prog, prog);
+   exit(1);
+}
+
+unsigned long
+component(const char *prog, const char *arg, int issRGB)
+{
+   char *ep;
+   unsigned long c = strtoul(arg, &ep, 0);
+
+   if (ep <= arg || *ep || c > 65535 || (issRGB && c > 255))
+   {
+      fprintf(stderr, "%s: %s: invalid component value (%lu)\n", prog, arg, c);
+      usage(prog);
+   }
+
+   return c;
+}
+
+int
+main(int argc, const char **argv)
+{
+   const char *prog = *argv++;
+   int to_linear = 0, to_gray = 0, to_color = 0;
+   int channels = 0;
+   double c[4];
+
+   /* FE_TONEAREST is the IEEE754 round to nearest, preferring even, mode; i.e.
+    * everything rounds to the nearest value except that '.5' rounds to the
+    * nearest even value.
+    */
+   fesetround(FE_TONEAREST);
+
+   c[3] = c[2] = c[1] = c[0] = 0;
+
+   while (--argc > 0 && **argv == '-')
+   {
+      const char *arg = 1+*argv++;
+
+      if (strcmp(arg, "sRGB") == 0)
+         to_linear = 0;
+
+      else if (strcmp(arg, "linear") == 0)
+         to_linear = 1;
+
+      else if (strcmp(arg, "gray") == 0)
+         to_gray = 1, to_color = 0;
+
+      else if (strcmp(arg, "color") == 0)
+         to_gray = 0, to_color = 1;
+
+      else
+         usage(prog);
+   }
+
+   switch (argc)
+   {
+      default:
+         usage(prog);
+         break;
+
+      case 4:
+         c[3] = component(prog, argv[3], to_linear);
+         ++channels;
+      case 3:
+         c[2] = component(prog, argv[2], to_linear);
+         ++channels;
+      case 2:
+         c[1] = component(prog, argv[1], to_linear);
+         ++channels;
+      case 1:
+         c[0] = component(prog, argv[0], to_linear);
+         ++channels;
+         break;
+      }
+
+   if (to_linear)
+   {
+      int i;
+      int components = channels;
+
+      if ((components & 1) == 0)
+         --components;
+
+      for (i=0; i<components; ++i) c[i] = linear_from_sRGB(c[i] / 255);
+      if (components < channels)
+         c[components] = c[components] / 255;
+   }
+
+   else
+   {
+      int i;
+      for (i=0; i<4; ++i) c[i] /= 65535;
+
+      if ((channels & 1) == 0)
+      {
+         double alpha = c[channels-1];
+
+         if (alpha > 0)
+            for (i=0; i<channels-1; ++i) c[i] /= alpha;
+         else
+            for (i=0; i<channels-1; ++i) c[i] = 1;
+      }
+   }
+
+   if (to_gray)
+   {
+      if (channels < 3)
+      {
+         fprintf(stderr, "%s: too few channels (%d) for -gray\n",
+            prog, channels);
+         usage(prog);
+      }
+
+      c[0] = YfromRGB(c[0], c[1], c[2]);
+      channels -= 2;
+   }
+
+   if (to_color)
+   {
+      if (channels > 2)
+      {
+         fprintf(stderr, "%s: too many channels (%d) for -color\n",
+            prog, channels);
+         usage(prog);
+      }
+
+      c[3] = c[1]; /* alpha, if present */
+      c[2] = c[1] = c[0];
+   }
+
+   if (to_linear)
+   {
+      int i;
+      if ((channels & 1) == 0)
+      {
+         double alpha = c[channels-1];
+         for (i=0; i<channels-1; ++i) c[i] *= alpha;
+      }
+
+      for (i=0; i<channels; ++i) c[i] = nearbyint(c[i] * 65535);
+   }
+
+   else /* to sRGB */
+   {
+      int i = (channels+1)&~1;
+      while (--i >= 0)
+         c[i] = sRGB_from_linear(c[i]);
+
+      for (i=0; i<channels; ++i) c[i] = nearbyint(c[i] * 255);
+   }
+
+   {
+      int i;
+      for (i=0; i<channels; ++i) printf(" %g", c[i]);
+   }
+   printf("\n");
+
+   return 0;
+}

contrib/tools/intgamma.sh

@@ -0,0 +1,110 @@
+#!/bin/sh
+#
+# intgamma.sh
+#
+# Last changed in libpng 1.6.0 [February 14, 2013]
+#
+# COPYRIGHT: Written by John Cunningham Bowler, 2013.
+# To the extent possible under law, the author has waived all copyright and
+# related or neighboring rights to this work.  This work is published from:
+# United States.
+#
+# Shell script to generate png.c 8-bit and 16-bit log tables (see the code in
+# png.c for details).
+#
+# This script uses the "bc" arbitrary precision calculator to calculate 32-bit
+# fixed point values of logarithms appropriate to finding the log of an 8-bit
+# (0..255) value and a similar table for the exponent calculation.
+#
+# "bc" must be on the path when the script is executed, and the math library
+# (-lm) must be available
+#
+# function to print out a list of numbers as integers; the function truncates
+# the integers which must be one-per-line
+function print(){
+   awk 'BEGIN{
+      str = ""
+   }
+   {
+      sub("\\.[0-9]*$", "")
+      if ($0 == "")
+         $0 = "0"
+
+      if (str == "")
+         t = "   " $0 "U"
+      else
+         t = str ", " $0 "U"
+
+      if (length(t) >= 80) {
+         print str ","
+         str = "   " $0 "U"
+      } else
+         str = t
+   }
+   END{
+      print str
+   }'
+}
+#
+# The logarithm table.
+cat <<END
+/* 8-bit log table: png_8bit_l2[128]
+ * This is a table of -log(value/255)/log(2) for 'value' in the range 128 to
+ * 255, so it's the base 2 logarithm of a normalized 8-bit floating point
+ * mantissa.  The numbers are 32-bit fractions.
+ */
+static const png_uint_32
+png_8bit_l2[128] =
+{
+END
+#
+bc -lqws <<END | print
+f=65536*65536/l(2)
+for (i=128;i<256;++i) { .5 - l(i/255)*f; }
+END
+echo '};'
+echo
+#
+# The exponent table.
+cat <<END
+/* The 'exp()' case must invert the above, taking a 20-bit fixed point
+ * logarithmic value and returning a 16 or 8-bit number as appropriate.  In
+ * each case only the low 16 bits are relevant - the fraction - since the
+ * integer bits (the top 4) simply determine a shift.
+ *
+ * The worst case is the 16-bit distinction between 65535 and 65534; this
+ * requires perhaps spurious accuracy in the decoding of the logarithm to
+ * distinguish log2(65535/65534.5) - 10^-5 or 17 bits.  There is little chance
+ * of getting this accuracy in practice.
+ *
+ * To deal with this the following exp() function works out the exponent of the
+ * frational part of the logarithm by using an accurate 32-bit value from the
+ * top four fractional bits then multiplying in the remaining bits.
+ */
+static const png_uint_32
+png_32bit_exp[16] =
+{
+END
+#
+bc -lqws <<END | print
+f=l(2)/16
+for (i=0;i<16;++i) {
+   x = .5 + e(-i*f)*2^32;
+   if (x >= 2^32) x = 2^32-1;
+   x;
+}
+END
+echo '};'
+echo
+#
+# And the table of adjustment values.
+cat <<END
+/* Adjustment table; provided to explain the numbers in the code below. */
+#if 0
+END
+bc -lqws <<END | awk '{ printf "%5d %s\n", 12-NR, $0 }'
+for (i=11;i>=0;--i){
+   (1 - e(-(2^i)/65536*l(2))) * 2^(32-i)
+}
+END
+echo '#endif'

contrib/tools/makesRGB.c

@@ -0,0 +1,430 @@
+/* makesRGB.c -- build sRGB-to-linear and linear-to-sRGB conversion tables
+ *
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2013.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Make a table to convert 8-bit sRGB encoding values into the closest 16-bit
+ * linear value.
+ *
+ * Make two tables to take a linear value scaled to 255*65535 and return an
+ * approximation to the 8-bit sRGB encoded value.  Calculate the error in these
+ * tables and display it.
+ */
+#define _C99_SOURCE 1
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+/* pngpriv.h includes the definition of 'PNG_sRGB_FROM_LINEAR' which is required
+ * to verify the actual code.
+ */
+#include "../../pngpriv.h"
+
+#include "sRGB.h"
+
+/* The tables are declared 'const' in pngpriv.h, so this redefines the tables to
+ * be used.
+ */
+#define png_sRGB_table sRGB_table
+#define png_sRGB_base sRGB_base
+#define png_sRGB_delta sRGB_delta
+
+static png_uint_16 png_sRGB_table[256];
+static png_uint_16 png_sRGB_base[512];
+static png_byte png_sRGB_delta[512];
+
+static const unsigned int max_input = 255*65535;
+
+double
+fsRGB(double l)
+{
+   return sRGB_from_linear(l/max_input);
+}
+
+double
+sRGB(unsigned int i)
+{
+   return fsRGB(i);
+}
+
+double
+finvsRGB(unsigned int i)
+{
+   return 65535 * linear_from_sRGB(i/255.);
+}
+
+png_uint_16
+invsRGB(unsigned int i)
+{
+   unsigned int x = nearbyint(finvsRGB(i));
+
+   if (x > 65535)
+   {
+      fprintf(stderr, "invsRGB(%u) overflows to %u\n", i, x);
+      exit(1);
+   }
+
+   return (png_uint_16)x;
+}
+
+int
+main(int argc, char **argv)
+{
+   unsigned int i, i16, ibase;
+   double min_error = 0;
+   double max_error = 0;
+   double min_error16 = 0;
+   double max_error16 = 0;
+   double adjust;
+   double adjust_lo = 0.4, adjust_hi = 0.6, adjust_mid = 0.5;
+   unsigned int ec_lo = 0, ec_hi = 0, ec_mid = 0;
+   unsigned int error_count = 0;
+   unsigned int error_count16 = 0;
+   int test_only = 0;
+
+   if (argc > 1)
+      test_only = strcmp("--test", argv[1]) == 0;
+
+   /* Initialize the encoding table first. */
+   for (i=0; i<256; ++i)
+   {
+      png_sRGB_table[i] = invsRGB(i);
+   }
+
+   /* Now work out the decoding tables (this is where the error comes in because
+    * there are 512 set points and 512 straight lines between them.)
+    */
+   for (;;)
+   {
+      if (ec_lo == 0)
+         adjust = adjust_lo;
+
+      else if (ec_hi == 0)
+         adjust = adjust_hi;
+
+      else if (ec_mid == 0)
+         adjust = adjust_mid;
+
+      else if (ec_mid < ec_hi)
+         adjust = (adjust_mid + adjust_hi)/2;
+
+      else if (ec_mid < ec_lo)
+         adjust = (adjust_mid + adjust_lo)/2;
+
+      else
+      {
+         fprintf(stderr, "not reached: %u .. %u .. %u\n", ec_lo, ec_mid, ec_hi);
+         exit(1);
+      }
+
+      /* Calculate the table using the current 'adjust' */
+      for (i=0; i<=511; ++i)
+      {
+         double lo = 255 * sRGB(i << 15);
+         double hi = 255 * sRGB((i+1) << 15);
+         unsigned int calc;
+
+         calc = nearbyint((lo+adjust) * 256);
+         if (calc > 65535)
+         {
+            fprintf(stderr, "table[%d][0]: overflow %08x (%d)\n", i, calc,
+               calc);
+            exit(1);
+         }
+         png_sRGB_base[i] = calc;
+
+         calc = nearbyint((hi-lo) * 32);
+         if (calc > 255)
+         {
+            fprintf(stderr, "table[%d][1]: overflow %08x (%d)\n", i, calc,
+               calc);
+            exit(1);
+         }
+         png_sRGB_delta[i] = calc;
+      }
+
+      /* Check the 16-bit linear values alone: */
+      error_count16 = 0;
+      for (i16=0; i16 <= 65535; ++i16)
+      {
+         unsigned int i = 255*i16;
+         unsigned int iexact = nearbyint(255*sRGB(i));
+         unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
+
+         if (icalc != iexact)
+            ++error_count16;
+      }
+
+      /* Now try changing the adjustment. */
+      if (ec_lo == 0)
+         ec_lo = error_count16;
+
+      else if (ec_hi == 0)
+         ec_hi = error_count16;
+
+      else if (ec_mid == 0)
+      {
+         ec_mid = error_count16;
+         printf("/* initial error counts: %u .. %u .. %u */\n", ec_lo, ec_mid,
+            ec_hi);
+      }
+
+      else if (error_count16 < ec_mid)
+      {
+         printf("/* adjust (mid ): %f: %u -> %u */\n", adjust, ec_mid,
+            error_count16);
+         ec_mid = error_count16;
+         adjust_mid = adjust;
+      }
+
+      else if (adjust < adjust_mid && error_count16 < ec_lo)
+      {
+         printf("/* adjust (low ): %f: %u -> %u */\n", adjust, ec_lo,
+            error_count16);
+         ec_lo = error_count16;
+         adjust_lo = adjust;
+      }
+
+      else if (adjust > adjust_mid && error_count16 < ec_hi)
+      {
+         printf("/* adjust (high): %f: %u -> %u */\n", adjust, ec_hi,
+            error_count16);
+         ec_hi = error_count16;
+         adjust_hi = adjust;
+      }
+
+      else
+      {
+         adjust = adjust_mid;
+         printf("/* adjust: %f: %u */\n", adjust, ec_mid);
+         break;
+      }
+   }
+
+   /* For each entry in the table try to adjust it to minimize the error count
+    * in that entry.  Each entry corresponds to 128 input values.
+    */
+   for (ibase=0; ibase<65536; ibase+=128)
+   {
+      png_uint_16 base = png_sRGB_base[ibase >> 7], trybase = base, ob=base;
+      png_byte delta = png_sRGB_delta[ibase >> 7], trydelta = delta, od=delta;
+      unsigned int ecbase = 0, eco;
+
+      for (;;)
+      {
+         png_sRGB_base[ibase >> 7] = trybase;
+         png_sRGB_delta[ibase >> 7] = trydelta;
+
+         /* Check the 16-bit linear values alone: */
+         error_count16 = 0;
+         for (i16=ibase; i16 < ibase+128; ++i16)
+         {
+            unsigned int i = 255*i16;
+            unsigned int iexact = nearbyint(255*sRGB(i));
+            unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
+
+            if (icalc != iexact)
+               ++error_count16;
+         }
+
+         if (error_count16 == 0)
+            break;
+
+         if (ecbase == 0)
+         {
+            eco = ecbase = error_count16;
+            ++trybase; /* First test */
+         }
+
+         else if (error_count16 < ecbase)
+         {
+            if (trybase > base)
+            {
+               base = trybase;
+               ++trybase;
+            }
+            else if (trybase < base)
+            {
+               base = trybase;
+               --trybase;
+            }
+            else if (trydelta > delta)
+            {
+               delta = trydelta;
+               ++trydelta;
+            }
+            else if (trydelta < delta)
+            {
+               delta = trydelta;
+               --trydelta;
+            }
+            else
+            {
+               fprintf(stderr, "makesRGB: impossible\n");
+               exit(1);
+            }
+            ecbase = error_count16;
+         }
+
+         else
+         {
+            if (trybase > base)
+               trybase = base-1;
+            else if (trybase < base)
+            {
+               trybase = base;
+               ++trydelta;
+            }
+            else if (trydelta > delta)
+               trydelta = delta-1;
+            else if (trydelta < delta)
+               break; /* end of tests */
+         }
+      }
+
+      png_sRGB_base[ibase >> 7] = base;
+      png_sRGB_delta[ibase >> 7] = delta;
+      if (base != ob || delta != od)
+      {
+         printf("/* table[%u]={%u,%u} -> {%u,%u} %u -> %u errors */\n",
+            ibase>>7, ob, od, base, delta, eco, ecbase);
+      }
+      else if (0)
+         printf("/* table[%u]={%u,%u} %u errors */\n", ibase>>7, ob, od,
+            ecbase);
+   }
+
+   /* Only do the full (slow) test at the end: */
+   min_error = -.4999;
+   max_error = .4999;
+   error_count = 0;
+
+   for (i=0; i <= max_input; ++i)
+   {
+      unsigned int iexact = nearbyint(255*sRGB(i));
+      unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
+
+      if (icalc != iexact)
+      {
+         double err = 255*sRGB(i) - icalc;
+
+         if (err > (max_error+.001) || err < (min_error-.001))
+         {
+            printf(
+               "/* 0x%08x: exact: %3d, got: %3d [tables: %08x, %08x] (%f) */\n",
+               i, iexact, icalc, png_sRGB_base[i>>15],
+               png_sRGB_delta[i>>15], err);
+         }
+
+         ++error_count;
+         if (err > max_error)
+            max_error = err;
+         else if (err < min_error)
+            min_error = err;
+      }
+   }
+
+   /* Re-check the 16-bit cases too, including the warning if there is an error
+    * bigger than 1.
+    */
+   error_count16 = 0;
+   max_error16 = 0;
+   min_error16 = 0;
+   for (i16=0; i16 <= 65535; ++i16)
+   {
+      unsigned int i = 255*i16;
+      unsigned int iexact = nearbyint(255*sRGB(i));
+      unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
+
+      if (icalc != iexact)
+      {
+         double err = 255*sRGB(i) - icalc;
+
+         ++error_count16;
+         if (err > max_error16)
+            max_error16 = err;
+         else if (err < min_error16)
+            min_error16 = err;
+
+         if (abs(icalc - iexact) > 1)
+            printf(
+               "/* 0x%04x: exact: %3d, got: %3d [tables: %08x, %08x] (%f) */\n",
+               i16, iexact, icalc, png_sRGB_base[i>>15],
+               png_sRGB_delta[i>>15], err);
+      }
+   }
+
+   /* Check the round trip for each 8-bit sRGB value. */
+   for (i16=0; i16 <= 255; ++i16)
+   {
+      unsigned int i = 255 * png_sRGB_table[i16];
+      unsigned int iexact = nearbyint(255*sRGB(i));
+      unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
+
+      if (i16 != iexact)
+      {
+         fprintf(stderr, "8-bit rounding error: %d -> %d\n", i16, iexact);
+         exit(1);
+      }
+
+      if (icalc != i16)
+      {
+         double finv = finvsRGB(i16);
+
+         printf("/* 8-bit roundtrip error: %d -> %f -> %d(%f) */\n",
+            i16, finv, icalc, fsRGB(255*finv));
+      }
+   }
+
+
+   printf("/* error: %g - %g, %u (%g%%) of readings inexact */\n",
+      min_error, max_error, error_count, (100.*error_count)/max_input);
+   printf("/* 16-bit error: %g - %g, %u (%g%%) of readings inexact */\n",
+      min_error16, max_error16, error_count16, (100.*error_count16)/65535);
+
+   if (!test_only)
+   {
+      printf("PNG_CONST png_uint_16 png_sRGB_table[256] =\n{\n   ");
+      for (i=0; i<255; )
+      {
+         do
+         {
+            printf("%d,", png_sRGB_table[i++]);
+         }
+         while ((i & 0x7) != 0 && i<255);
+         if (i<255) printf("\n   ");
+      }
+      printf("%d\n};\n\n", png_sRGB_table[i]);
+
+
+      printf("PNG_CONST png_uint_16 png_sRGB_base[512] =\n{\n   ");
+      for (i=0; i<511; )
+      {
+         do
+         {
+            printf("%d,", png_sRGB_base[i++]);
+         }
+         while ((i & 0x7) != 0 && i<511);
+         if (i<511) printf("\n   ");
+      }
+      printf("%d\n};\n\n", png_sRGB_base[i]);
+
+      printf("PNG_CONST png_byte png_sRGB_delta[512] =\n{\n   ");
+      for (i=0; i<511; )
+      {
+         do
+         {
+            printf("%d,", png_sRGB_delta[i++]);
+         }
+         while ((i & 0xf) != 0 && i<511);
+         if (i<511) printf("\n   ");
+      }
+      printf("%d\n};\n\n", png_sRGB_delta[i]);
+   }
+
+   return 0;
+}

contrib/tools/png-fix-itxt.c

@@ -0,0 +1,153 @@
+
+/* png-fix-itxt version 1.0.0
+ *
+ * Copyright 2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.3 [July 18, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Usage:            
+ *
+ *     png-fix-itxt.exe < bad.png > good.png
+ *
+ * Fixes a PNG file written with libpng-1.6.0 or 1.6.1 that has one or more
+ * uncompressed iTXt chunks.  Assumes that the actual length is greater
+ * than or equal to the value in the length byte, and that the CRC is
+ * correct for the actual length.  This program hunts for the CRC and
+ * adjusts the length byte accordingly.  It is not an error to process a
+ * PNG file that has no iTXt chunks or one that has valid iTXt chunks;
+ * such files will simply be copied.
+ *
+ * Requires zlib (for crc32 and Z_NULL); build with
+ *
+ *     gcc -O -o png-fix-itxt png-fix-itxt.c -lz
+ *
+ * If you need to handle iTXt chunks larger than 500000 kbytes you must
+ * rebuild png-fix-itxt with a larger values of MAX_LENGTH (or a smaller value
+ * if you know you will never encounter such huge iTXt chunks).
+ */
+
+#include <stdio.h>
+#include <zlib.h>
+
+#define MAX_LENGTH 500000
+
+#define GETBREAK ((unsigned char)(inchar=getchar())); if (inchar == EOF) break
+
+int
+main(void)
+{
+   unsigned int i;
+   unsigned char buf[MAX_LENGTH];
+   unsigned long crc;
+   unsigned char c;
+   int inchar;
+
+/* Skip 8-byte signature */
+   for (i=8; i; i--)
+   {
+      c=GETBREAK;
+      putchar(c);
+   }
+
+if (inchar != EOF)
+for (;;)
+ {
+   /* Read the length */
+   unsigned long length; /* must be 32 bits! */
+   c=GETBREAK; buf[0] = c; length  = c; length <<= 8;
+   c=GETBREAK; buf[1] = c; length += c; length <<= 8;
+   c=GETBREAK; buf[2] = c; length += c; length <<= 8;
+   c=GETBREAK; buf[3] = c; length += c;
+
+   /* Read the chunkname */
+   c=GETBREAK; buf[4] = c;
+   c=GETBREAK; buf[5] = c;
+   c=GETBREAK; buf[6] = c;
+   c=GETBREAK; buf[7] = c;
+
+
+   /* The iTXt chunk type expressed as integers is (105, 84, 88, 116) */
+   if (buf[4] == 105 && buf[5] == 84 && buf[6] == 88 && buf[7] == 116)
+   {
+      if (length >= MAX_LENGTH-12)
+         break;  /* To do: handle this more gracefully */
+
+      /* Initialize the CRC */
+      crc = crc32(0, Z_NULL, 0);
+
+      /* Copy the data bytes */
+      for (i=8; i < length + 12; i++)
+      {
+         c=GETBREAK; buf[i] = c;
+      }
+
+      /* Calculate the CRC */
+      crc = crc32(crc, buf+4, (uInt)length+4);
+
+      for (;;)
+      {
+        /* Check the CRC */
+        if (((crc >> 24) & 0xff) == buf[length+8] &&
+            ((crc >> 16) & 0xff) == buf[length+9] &&
+            ((crc >>  8) & 0xff) == buf[length+10] &&
+            ((crc      ) & 0xff) == buf[length+11])
+           break;
+
+        length++;
+
+        if (length >= MAX_LENGTH-12)
+           break;
+
+        c=GETBREAK;
+        buf[length+11]=c;
+
+        /* Update the CRC */
+        crc = crc32(crc, buf+7+length, 1);
+      }
+
+      /* Update length bytes */
+      buf[0] = (unsigned char)((length << 24) & 0xff);
+      buf[1] = (unsigned char)((length << 16) & 0xff);
+      buf[2] = (unsigned char)((length <<  8) & 0xff);
+      buf[3] = (unsigned char)((length      ) & 0xff);
+
+      /* Write the fixed iTXt chunk (length, name, data, crc) */
+      for (i=0; i<length+12; i++)
+         putchar(buf[i]);
+   }
+
+   else
+   {
+      /* Copy bytes that were already read (length and chunk name) */
+      for (i=0; i<8; i++)
+         putchar(buf[i]);
+
+      /* Copy data bytes and CRC */
+      for (i=8; i< length+12; i++)
+      {
+         c=GETBREAK;
+         putchar(c);
+      }
+
+      if (inchar == EOF)
+      {
+         break;
+      }
+
+   /* The IEND chunk type expressed as integers is (73, 69, 78, 68) */
+      if (buf[4] == 73 && buf[5] == 69 && buf[6] == 78 && buf[7] == 68)
+         break;
+   }
+
+   if (inchar == EOF)
+      break;
+
+   if (buf[4] == 73 && buf[5] == 69 && buf[6] == 78 && buf[7] == 68)
+     break;
+ }
+
+ return 0;
+}

contrib/tools/sRGB.h

@@ -0,0 +1,48 @@
+/*-
+ * sRGB.h
+ *
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2013.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Utility file; not actually a header, this contains definitions of sRGB
+ * calculation functions for inclusion in those test programs that need them.
+ *
+ * All routines take and return a floating point value in the range
+ * 0 to 1.0, doing a calculation according to the sRGB specification
+ * (in fact the source of the numbers is the wikipedia article at
+ * http://en.wikipedia.org/wiki/SRGB).
+ */
+static double
+sRGB_from_linear(double l)
+{
+   if (l <= 0.0031308)
+      l *= 12.92;
+
+   else
+      l = 1.055 * pow(l, 1/2.4) - 0.055;
+
+   return l;
+}
+
+static double
+linear_from_sRGB(double s)
+{
+   if (s <= 0.04045)
+      return s / 12.92;
+
+   else
+      return pow((s+0.055)/1.055, 2.4);
+}
+
+static double
+YfromRGB(double r, double g, double b)
+{
+   /* Use the sRGB (rounded) coefficients for Rlinear, Glinear, Blinear to get
+    * the CIE Y value (also linear).
+    */
+   return 0.2126 * r + 0.7152 * g + 0.0722 * b;
+}

depcomp

@@ -1,790 +0,0 @@
-#! /bin/sh
-# depcomp - compile a program generating dependencies as side-effects
-
-scriptversion=2012-10-18.11; # UTC
-
-# Copyright (C) 1999-2012 Free Software Foundation, Inc.
-
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2, or (at your option)
-# any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-# As a special exception to the GNU General Public License, if you
-# distribute this file as part of a program that contains a
-# configuration script generated by Autoconf, you may include it under
-# the same distribution terms that you use for the rest of that program.
-
-# Originally written by Alexandre Oliva <oliva@dcc.unicamp.br>.
-
-case $1 in
-  '')
-    echo "$0: No command.  Try '$0 --help' for more information." 1>&2
-    exit 1;
-    ;;
-  -h | --h*)
-    cat <<\EOF
-Usage: depcomp [--help] [--version] PROGRAM [ARGS]
-
-Run PROGRAMS ARGS to compile a file, generating dependencies
-as side-effects.
-
-Environment variables:
-  depmode     Dependency tracking mode.
-  source      Source file read by 'PROGRAMS ARGS'.
-  object      Object file output by 'PROGRAMS ARGS'.
-  DEPDIR      directory where to store dependencies.
-  depfile     Dependency file to output.
-  tmpdepfile  Temporary file to use when outputting dependencies.
-  libtool     Whether libtool is used (yes/no).
-
-Report bugs to <bug-automake@gnu.org>.
-EOF
-    exit $?
-    ;;
-  -v | --v*)
-    echo "depcomp $scriptversion"
-    exit $?
-    ;;
-esac
-
-# Get the directory component of the given path, and save it in the
-# global variables '$dir'.  Note that this directory component will
-# be either empty or ending with a '/' character.  This is deliberate.
-set_dir_from ()
-{
-  case $1 in
-    */*) dir=`echo "$1" | sed -e 's|/[^/]*$|/|'`;;
-      *) dir=;;
-  esac
-}
-
-# Get the suffix-stripped basename of the given path, and save it the
-# global variable '$base'.
-set_base_from ()
-{
-  base=`echo "$1" | sed -e 's|^.*/||' -e 's/\.[^.]*$//'`
-}
-
-# If no dependency file was actually created by the compiler invocation,
-# we still have to create a dummy depfile, to avoid errors with the
-# Makefile "include basename.Plo" scheme.
-make_dummy_depfile ()
-{
-  echo "#dummy" > "$depfile"
-}
-
-# Factor out some common post-processing of the generated depfile.
-# Requires the auxiliary global variable '$tmpdepfile' to be set.
-aix_post_process_depfile ()
-{
-  # If the compiler actually managed to produce a dependency file,
-  # post-process it.
-  if test -f "$tmpdepfile"; then
-    # Each line is of the form 'foo.o: dependency.h'.
-    # Do two passes, one to just change these to
-    #   $object: dependency.h
-    # and one to simply output
-    #   dependency.h:
-    # which is needed to avoid the deleted-header problem.
-    { sed -e "s,^.*\.[$lower]*:,$object:," < "$tmpdepfile"
-      sed -e "s,^.*\.[$lower]*:[$tab ]*,," -e 's,$,:,' < "$tmpdepfile"
-    } > "$depfile"
-    rm -f "$tmpdepfile"
-  else
-    make_dummy_depfile
-  fi
-}
-
-# A tabulation character.
-tab='	'
-# A newline character.
-nl='
-'
-# Character ranges might be problematic outside the C locale.
-# These definitions help.
-upper=ABCDEFGHIJKLMNOPQRSTUVWXYZ
-lower=abcdefghijklmnopqrstuvwxyz
-digits=0123456789
-alpha=${upper}${lower}
-
-if test -z "$depmode" || test -z "$source" || test -z "$object"; then
-  echo "depcomp: Variables source, object and depmode must be set" 1>&2
-  exit 1
-fi
-
-# Dependencies for sub/bar.o or sub/bar.obj go into sub/.deps/bar.Po.
-depfile=${depfile-`echo "$object" |
-  sed 's|[^\\/]*$|'${DEPDIR-.deps}'/&|;s|\.\([^.]*\)$|.P\1|;s|Pobj$|Po|'`}
-tmpdepfile=${tmpdepfile-`echo "$depfile" | sed 's/\.\([^.]*\)$/.T\1/'`}
-
-rm -f "$tmpdepfile"
-
-# Avoid interferences from the environment.
-gccflag= dashmflag=
-
-# Some modes work just like other modes, but use different flags.  We
-# parameterize here, but still list the modes in the big case below,
-# to make depend.m4 easier to write.  Note that we *cannot* use a case
-# here, because this file can only contain one case statement.
-if test "$depmode" = hp; then
-  # HP compiler uses -M and no extra arg.
-  gccflag=-M
-  depmode=gcc
-fi
-
-if test "$depmode" = dashXmstdout; then
-  # This is just like dashmstdout with a different argument.
-  dashmflag=-xM
-  depmode=dashmstdout
-fi
-
-cygpath_u="cygpath -u -f -"
-if test "$depmode" = msvcmsys; then
-  # This is just like msvisualcpp but w/o cygpath translation.
-  # Just convert the backslash-escaped backslashes to single forward
-  # slashes to satisfy depend.m4
-  cygpath_u='sed s,\\\\,/,g'
-  depmode=msvisualcpp
-fi
-
-if test "$depmode" = msvc7msys; then
-  # This is just like msvc7 but w/o cygpath translation.
-  # Just convert the backslash-escaped backslashes to single forward
-  # slashes to satisfy depend.m4
-  cygpath_u='sed s,\\\\,/,g'
-  depmode=msvc7
-fi
-
-if test "$depmode" = xlc; then
-  # IBM C/C++ Compilers xlc/xlC can output gcc-like dependency information.
-  gccflag=-qmakedep=gcc,-MF
-  depmode=gcc
-fi
-
-case "$depmode" in
-gcc3)
-## gcc 3 implements dependency tracking that does exactly what
-## we want.  Yay!  Note: for some reason libtool 1.4 doesn't like
-## it if -MD -MP comes after the -MF stuff.  Hmm.
-## Unfortunately, FreeBSD c89 acceptance of flags depends upon
-## the command line argument order; so add the flags where they
-## appear in depend2.am.  Note that the slowdown incurred here
-## affects only configure: in makefiles, %FASTDEP% shortcuts this.
-  for arg
-  do
-    case $arg in
-    -c) set fnord "$@" -MT "$object" -MD -MP -MF "$tmpdepfile" "$arg" ;;
-    *)  set fnord "$@" "$arg" ;;
-    esac
-    shift # fnord
-    shift # $arg
-  done
-  "$@"
-  stat=$?
-  if test $stat -ne 0; then
-    rm -f "$tmpdepfile"
-    exit $stat
-  fi
-  mv "$tmpdepfile" "$depfile"
-  ;;
-
-gcc)
-## Note that this doesn't just cater to obsosete pre-3.x GCC compilers.
-## but also to in-use compilers like IMB xlc/xlC and the HP C compiler.
-## (see the conditional assignment to $gccflag above).
-## There are various ways to get dependency output from gcc.  Here's
-## why we pick this rather obscure method:
-## - Don't want to use -MD because we'd like the dependencies to end
-##   up in a subdir.  Having to rename by hand is ugly.
-##   (We might end up doing this anyway to support other compilers.)
-## - The DEPENDENCIES_OUTPUT environment variable makes gcc act like
-##   -MM, not -M (despite what the docs say).  Also, it might not be
-##   supported by the other compilers which use the 'gcc' depmode.
-## - Using -M directly means running the compiler twice (even worse
-##   than renaming).
-  if test -z "$gccflag"; then
-    gccflag=-MD,
-  fi
-  "$@" -Wp,"$gccflag$tmpdepfile"
-  stat=$?
-  if test $stat -ne 0; then
-    rm -f "$tmpdepfile"
-    exit $stat
-  fi
-  rm -f "$depfile"
-  echo "$object : \\" > "$depfile"
-  # The second -e expression handles DOS-style file names with drive
-  # letters.
-  sed -e 's/^[^:]*: / /' \
-      -e 's/^['$alpha']:\/[^:]*: / /' < "$tmpdepfile" >> "$depfile"
-## This next piece of magic avoids the "deleted header file" problem.
-## The problem is that when a header file which appears in a .P file
-## is deleted, the dependency causes make to die (because there is
-## typically no way to rebuild the header).  We avoid this by adding
-## dummy dependencies for each header file.  Too bad gcc doesn't do
-## this for us directly.
-## Some versions of gcc put a space before the ':'.  On the theory
-## that the space means something, we add a space to the output as
-## well.  hp depmode also adds that space, but also prefixes the VPATH
-## to the object.  Take care to not repeat it in the output.
-## Some versions of the HPUX 10.20 sed can't process this invocation
-## correctly.  Breaking it into two sed invocations is a workaround.
-  tr ' ' "$nl" < "$tmpdepfile" \
-    | sed -e 's/^\\$//' -e '/^$/d' -e "s|.*$object$||" -e '/:$/d' \
-    | sed -e 's/$/ :/' >> "$depfile"
-  rm -f "$tmpdepfile"
-  ;;
-
-hp)
-  # This case exists only to let depend.m4 do its work.  It works by
-  # looking at the text of this script.  This case will never be run,
-  # since it is checked for above.
-  exit 1
-  ;;
-
-sgi)
-  if test "$libtool" = yes; then
-    "$@" "-Wp,-MDupdate,$tmpdepfile"
-  else
-    "$@" -MDupdate "$tmpdepfile"
-  fi
-  stat=$?
-  if test $stat -ne 0; then
-    rm -f "$tmpdepfile"
-    exit $stat
-  fi
-  rm -f "$depfile"
-
-  if test -f "$tmpdepfile"; then  # yes, the sourcefile depend on other files
-    echo "$object : \\" > "$depfile"
-    # Clip off the initial element (the dependent).  Don't try to be
-    # clever and replace this with sed code, as IRIX sed won't handle
-    # lines with more than a fixed number of characters (4096 in
-    # IRIX 6.2 sed, 8192 in IRIX 6.5).  We also remove comment lines;
-    # the IRIX cc adds comments like '#:fec' to the end of the
-    # dependency line.
-    tr ' ' "$nl" < "$tmpdepfile" \
-      | sed -e 's/^.*\.o://' -e 's/#.*$//' -e '/^$/ d' \
-      | tr "$nl" ' ' >> "$depfile"
-    echo >> "$depfile"
-    # The second pass generates a dummy entry for each header file.
-    tr ' ' "$nl" < "$tmpdepfile" \
-      | sed -e 's/^.*\.o://' -e 's/#.*$//' -e '/^$/ d' -e 's/$/:/' \
-      >> "$depfile"
-  else
-    make_dummy_depfile
-  fi
-  rm -f "$tmpdepfile"
-  ;;
-
-xlc)
-  # This case exists only to let depend.m4 do its work.  It works by
-  # looking at the text of this script.  This case will never be run,
-  # since it is checked for above.
-  exit 1
-  ;;
-
-aix)
-  # The C for AIX Compiler uses -M and outputs the dependencies
-  # in a .u file.  In older versions, this file always lives in the
-  # current directory.  Also, the AIX compiler puts '$object:' at the
-  # start of each line; $object doesn't have directory information.
-  # Version 6 uses the directory in both cases.
-  set_dir_from "$object"
-  set_base_from "$object"
-  if test "$libtool" = yes; then
-    tmpdepfile1=$dir$base.u
-    tmpdepfile2=$base.u
-    tmpdepfile3=$dir.libs/$base.u
-    "$@" -Wc,-M
-  else
-    tmpdepfile1=$dir$base.u
-    tmpdepfile2=$dir$base.u
-    tmpdepfile3=$dir$base.u
-    "$@" -M
-  fi
-  stat=$?
-  if test $stat -ne 0; then
-    rm -f "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
-    exit $stat
-  fi
-
-  for tmpdepfile in "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
-  do
-    test -f "$tmpdepfile" && break
-  done
-  aix_post_process_depfile
-  ;;
-
-tcc)
-  # tcc (Tiny C Compiler) understand '-MD -MF file' since version 0.9.26
-  # FIXME: That version still under development at the moment of writing.
-  #        Make that this statement remains true also for stable, released
-  #        versions.
-  # It will wrap lines (doesn't matter whether long or short) with a
-  # trailing '\', as in:
-  #
-  #   foo.o : \
-  #    foo.c \
-  #    foo.h \
-  #
-  # It will put a trailing '\' even on the last line, and will use leading
-  # spaces rather than leading tabs (at least since its commit 0394caf7
-  # "Emit spaces for -MD").
-  "$@" -MD -MF "$tmpdepfile"
-  stat=$?
-  if test $stat -ne 0; then
-    rm -f "$tmpdepfile"
-    exit $stat
-  fi
-  rm -f "$depfile"
-  # Each non-empty line is of the form 'foo.o : \' or ' dep.h \'.
-  # We have to change lines of the first kind to '$object: \'.
-  sed -e "s|.*:|$object :|" < "$tmpdepfile" > "$depfile"
-  # And for each line of the second kind, we have to emit a 'dep.h:'
-  # dummy dependency, to avoid the deleted-header problem.
-  sed -n -e 's|^  *\(.*\) *\\$|\1:|p' < "$tmpdepfile" >> "$depfile"
-  rm -f "$tmpdepfile"
-  ;;
-
-## The order of this option in the case statement is important, since the
-## shell code in configure will try each of these formats in the order
-## listed in this file.  A plain '-MD' option would be understood by many
-## compilers, so we must ensure this comes after the gcc and icc options.
-pgcc)
-  # Portland's C compiler understands '-MD'.
-  # Will always output deps to 'file.d' where file is the root name of the
-  # source file under compilation, even if file resides in a subdirectory.
-  # The object file name does not affect the name of the '.d' file.
-  # pgcc 10.2 will output
-  #    foo.o: sub/foo.c sub/foo.h
-  # and will wrap long lines using '\' :
-  #    foo.o: sub/foo.c ... \
-  #     sub/foo.h ... \
-  #     ...
-  set_dir_from "$object"
-  # Use the source, not the object, to determine the base name, since
-  # that's sadly what pgcc will do too.
-  set_base_from "$source"
-  tmpdepfile=$base.d
-
-  # For projects that build the same source file twice into different object
-  # files, the pgcc approach of using the *source* file root name can cause
-  # problems in parallel builds.  Use a locking strategy to avoid stomping on
-  # the same $tmpdepfile.
-  lockdir=$base.d-lock
-  trap "
-    echo '$0: caught signal, cleaning up...' >&2
-    rmdir '$lockdir'
-    exit 1
-  " 1 2 13 15
-  numtries=100
-  i=$numtries
-  while test $i -gt 0; do
-    # mkdir is a portable test-and-set.
-    if mkdir "$lockdir" 2>/dev/null; then
-      # This process acquired the lock.
-      "$@" -MD
-      stat=$?
-      # Release the lock.
-      rmdir "$lockdir"
-      break
-    else
-      # If the lock is being held by a different process, wait
-      # until the winning process is done or we timeout.
-      while test -d "$lockdir" && test $i -gt 0; do
-        sleep 1
-        i=`expr $i - 1`
-      done
-    fi
-    i=`expr $i - 1`
-  done
-  trap - 1 2 13 15
-  if test $i -le 0; then
-    echo "$0: failed to acquire lock after $numtries attempts" >&2
-    echo "$0: check lockdir '$lockdir'" >&2
-    exit 1
-  fi
-
-  if test $stat -ne 0; then
-    rm -f "$tmpdepfile"
-    exit $stat
-  fi
-  rm -f "$depfile"
-  # Each line is of the form `foo.o: dependent.h',
-  # or `foo.o: dep1.h dep2.h \', or ` dep3.h dep4.h \'.
-  # Do two passes, one to just change these to
-  # `$object: dependent.h' and one to simply `dependent.h:'.
-  sed "s,^[^:]*:,$object :," < "$tmpdepfile" > "$depfile"
-  # Some versions of the HPUX 10.20 sed can't process this invocation
-  # correctly.  Breaking it into two sed invocations is a workaround.
-  sed 's,^[^:]*: \(.*\)$,\1,;s/^\\$//;/^$/d;/:$/d' < "$tmpdepfile" \
-    | sed -e 's/$/ :/' >> "$depfile"
-  rm -f "$tmpdepfile"
-  ;;
-
-hp2)
-  # The "hp" stanza above does not work with aCC (C++) and HP's ia64
-  # compilers, which have integrated preprocessors.  The correct option
-  # to use with these is +Maked; it writes dependencies to a file named
-  # 'foo.d', which lands next to the object file, wherever that
-  # happens to be.
-  # Much of this is similar to the tru64 case; see comments there.
-  set_dir_from  "$object"
-  set_base_from "$object"
-  if test "$libtool" = yes; then
-    tmpdepfile1=$dir$base.d
-    tmpdepfile2=$dir.libs/$base.d
-    "$@" -Wc,+Maked
-  else
-    tmpdepfile1=$dir$base.d
-    tmpdepfile2=$dir$base.d
-    "$@" +Maked
-  fi
-  stat=$?
-  if test $stat -ne 0; then
-     rm -f "$tmpdepfile1" "$tmpdepfile2"
-     exit $stat
-  fi
-
-  for tmpdepfile in "$tmpdepfile1" "$tmpdepfile2"
-  do
-    test -f "$tmpdepfile" && break
-  done
-  if test -f "$tmpdepfile"; then
-    sed -e "s,^.*\.[$lower]*:,$object:," "$tmpdepfile" > "$depfile"
-    # Add 'dependent.h:' lines.
-    sed -ne '2,${
-               s/^ *//
-               s/ \\*$//
-               s/$/:/
-               p
-             }' "$tmpdepfile" >> "$depfile"
-  else
-    make_dummy_depfile
-  fi
-  rm -f "$tmpdepfile" "$tmpdepfile2"
-  ;;
-
-tru64)
-  # The Tru64 compiler uses -MD to generate dependencies as a side
-  # effect.  'cc -MD -o foo.o ...' puts the dependencies into 'foo.o.d'.
-  # At least on Alpha/Redhat 6.1, Compaq CCC V6.2-504 seems to put
-  # dependencies in 'foo.d' instead, so we check for that too.
-  # Subdirectories are respected.
-  set_dir_from  "$object"
-  set_base_from "$object"
-
-  if test "$libtool" = yes; then
-    # Libtool generates 2 separate objects for the 2 libraries.  These
-    # two compilations output dependencies in $dir.libs/$base.o.d and
-    # in $dir$base.o.d.  We have to check for both files, because
-    # one of the two compilations can be disabled.  We should prefer
-    # $dir$base.o.d over $dir.libs/$base.o.d because the latter is
-    # automatically cleaned when .libs/ is deleted, while ignoring
-    # the former would cause a distcleancheck panic.
-    tmpdepfile1=$dir$base.o.d          # libtool 1.5
-    tmpdepfile2=$dir.libs/$base.o.d    # Likewise.
-    tmpdepfile3=$dir.libs/$base.d      # Compaq CCC V6.2-504
-    "$@" -Wc,-MD
-  else
-    tmpdepfile1=$dir$base.d
-    tmpdepfile2=$dir$base.d
-    tmpdepfile3=$dir$base.d
-    "$@" -MD
-  fi
-
-  stat=$?
-  if test $stat -ne 0; then
-    rm -f "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
-    exit $stat
-  fi
-
-  for tmpdepfile in "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
-  do
-    test -f "$tmpdepfile" && break
-  done
-  # Same post-processing that is required for AIX mode.
-  aix_post_process_depfile
-  ;;
-
-msvc7)
-  if test "$libtool" = yes; then
-    showIncludes=-Wc,-showIncludes
-  else
-    showIncludes=-showIncludes
-  fi
-  "$@" $showIncludes > "$tmpdepfile"
-  stat=$?
-  grep -v '^Note: including file: ' "$tmpdepfile"
-  if test $stat -ne 0; then
-    rm -f "$tmpdepfile"
-    exit $stat
-  fi
-  rm -f "$depfile"
-  echo "$object : \\" > "$depfile"
-  # The first sed program below extracts the file names and escapes
-  # backslashes for cygpath.  The second sed program outputs the file
-  # name when reading, but also accumulates all include files in the
-  # hold buffer in order to output them again at the end.  This only
-  # works with sed implementations that can handle large buffers.
-  sed < "$tmpdepfile" -n '
-/^Note: including file:  *\(.*\)/ {
-  s//\1/
-  s/\\/\\\\/g
-  p
-}' | $cygpath_u | sort -u | sed -n '
-s/ /\\ /g
-s/\(.*\)/'"$tab"'\1 \\/p
-s/.\(.*\) \\/\1:/
-H
-$ {
-  s/.*/'"$tab"'/
-  G
-  p
-}' >> "$depfile"
-  rm -f "$tmpdepfile"
-  ;;
-
-msvc7msys)
-  # This case exists only to let depend.m4 do its work.  It works by
-  # looking at the text of this script.  This case will never be run,
-  # since it is checked for above.
-  exit 1
-  ;;
-
-#nosideeffect)
-  # This comment above is used by automake to tell side-effect
-  # dependency tracking mechanisms from slower ones.
-
-dashmstdout)
-  # Important note: in order to support this mode, a compiler *must*
-  # always write the preprocessed file to stdout, regardless of -o.
-  "$@" || exit $?
-
-  # Remove the call to Libtool.
-  if test "$libtool" = yes; then
-    while test "X$1" != 'X--mode=compile'; do
-      shift
-    done
-    shift
-  fi
-
-  # Remove '-o $object'.
-  IFS=" "
-  for arg
-  do
-    case $arg in
-    -o)
-      shift
-      ;;
-    $object)
-      shift
-      ;;
-    *)
-      set fnord "$@" "$arg"
-      shift # fnord
-      shift # $arg
-      ;;
-    esac
-  done
-
-  test -z "$dashmflag" && dashmflag=-M
-  # Require at least two characters before searching for ':'
-  # in the target name.  This is to cope with DOS-style filenames:
-  # a dependency such as 'c:/foo/bar' could be seen as target 'c' otherwise.
-  "$@" $dashmflag |
-    sed "s|^[$tab ]*[^:$tab ][^:][^:]*:[$tab ]*|$object: |" > "$tmpdepfile"
-  rm -f "$depfile"
-  cat < "$tmpdepfile" > "$depfile"
-  # Some versions of the HPUX 10.20 sed can't process this sed invocation
-  # correctly.  Breaking it into two sed invocations is a workaround.
-  tr ' ' "$nl" < "$tmpdepfile" \
-    | sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' \
-    | sed -e 's/$/ :/' >> "$depfile"
-  rm -f "$tmpdepfile"
-  ;;
-
-dashXmstdout)
-  # This case only exists to satisfy depend.m4.  It is never actually
-  # run, as this mode is specially recognized in the preamble.
-  exit 1
-  ;;
-
-makedepend)
-  "$@" || exit $?
-  # Remove any Libtool call
-  if test "$libtool" = yes; then
-    while test "X$1" != 'X--mode=compile'; do
-      shift
-    done
-    shift
-  fi
-  # X makedepend
-  shift
-  cleared=no eat=no
-  for arg
-  do
-    case $cleared in
-    no)
-      set ""; shift
-      cleared=yes ;;
-    esac
-    if test $eat = yes; then
-      eat=no
-      continue
-    fi
-    case "$arg" in
-    -D*|-I*)
-      set fnord "$@" "$arg"; shift ;;
-    # Strip any option that makedepend may not understand.  Remove
-    # the object too, otherwise makedepend will parse it as a source file.
-    -arch)
-      eat=yes ;;
-    -*|$object)
-      ;;
-    *)
-      set fnord "$@" "$arg"; shift ;;
-    esac
-  done
-  obj_suffix=`echo "$object" | sed 's/^.*\././'`
-  touch "$tmpdepfile"
-  ${MAKEDEPEND-makedepend} -o"$obj_suffix" -f"$tmpdepfile" "$@"
-  rm -f "$depfile"
-  # makedepend may prepend the VPATH from the source file name to the object.
-  # No need to regex-escape $object, excess matching of '.' is harmless.
-  sed "s|^.*\($object *:\)|\1|" "$tmpdepfile" > "$depfile"
-  # Some versions of the HPUX 10.20 sed can't process the last invocation
-  # correctly.  Breaking it into two sed invocations is a workaround.
-  sed '1,2d' "$tmpdepfile" \
-    | tr ' ' "$nl" \
-    | sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' \
-    | sed -e 's/$/ :/' >> "$depfile"
-  rm -f "$tmpdepfile" "$tmpdepfile".bak
-  ;;
-
-cpp)
-  # Important note: in order to support this mode, a compiler *must*
-  # always write the preprocessed file to stdout.
-  "$@" || exit $?
-
-  # Remove the call to Libtool.
-  if test "$libtool" = yes; then
-    while test "X$1" != 'X--mode=compile'; do
-      shift
-    done
-    shift
-  fi
-
-  # Remove '-o $object'.
-  IFS=" "
-  for arg
-  do
-    case $arg in
-    -o)
-      shift
-      ;;
-    $object)
-      shift
-      ;;
-    *)
-      set fnord "$@" "$arg"
-      shift # fnord
-      shift # $arg
-      ;;
-    esac
-  done
-
-  "$@" -E \
-    | sed -n -e '/^# [0-9][0-9]* "\([^"]*\)".*/ s:: \1 \\:p' \
-             -e '/^#line [0-9][0-9]* "\([^"]*\)".*/ s:: \1 \\:p' \
-    | sed '$ s: \\$::' > "$tmpdepfile"
-  rm -f "$depfile"
-  echo "$object : \\" > "$depfile"
-  cat < "$tmpdepfile" >> "$depfile"
-  sed < "$tmpdepfile" '/^$/d;s/^ //;s/ \\$//;s/$/ :/' >> "$depfile"
-  rm -f "$tmpdepfile"
-  ;;
-
-msvisualcpp)
-  # Important note: in order to support this mode, a compiler *must*
-  # always write the preprocessed file to stdout.
-  "$@" || exit $?
-
-  # Remove the call to Libtool.
-  if test "$libtool" = yes; then
-    while test "X$1" != 'X--mode=compile'; do
-      shift
-    done
-    shift
-  fi
-
-  IFS=" "
-  for arg
-  do
-    case "$arg" in
-    -o)
-      shift
-      ;;
-    $object)
-      shift
-      ;;
-    "-Gm"|"/Gm"|"-Gi"|"/Gi"|"-ZI"|"/ZI")
-        set fnord "$@"
-        shift
-        shift
-        ;;
-    *)
-        set fnord "$@" "$arg"
-        shift
-        shift
-        ;;
-    esac
-  done
-  "$@" -E 2>/dev/null |
-  sed -n '/^#line [0-9][0-9]* "\([^"]*\)"/ s::\1:p' | $cygpath_u | sort -u > "$tmpdepfile"
-  rm -f "$depfile"
-  echo "$object : \\" > "$depfile"
-  sed < "$tmpdepfile" -n -e 's% %\\ %g' -e '/^\(.*\)$/ s::'"$tab"'\1 \\:p' >> "$depfile"
-  echo "$tab" >> "$depfile"
-  sed < "$tmpdepfile" -n -e 's% %\\ %g' -e '/^\(.*\)$/ s::\1\::p' >> "$depfile"
-  rm -f "$tmpdepfile"
-  ;;
-
-msvcmsys)
-  # This case exists only to let depend.m4 do its work.  It works by
-  # looking at the text of this script.  This case will never be run,
-  # since it is checked for above.
-  exit 1
-  ;;
-
-none)
-  exec "$@"
-  ;;
-
-*)
-  echo "Unknown depmode $depmode" 1>&2
-  exit 1
-  ;;
-esac
-
-exit 0
-
-# Local Variables:
-# mode: shell-script
-# sh-indentation: 2
-# eval: (add-hook 'write-file-hooks 'time-stamp)
-# time-stamp-start: "scriptversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
-# time-stamp-time-zone: "UTC"
-# time-stamp-end: "; # UTC"
-# End:

example.c

@@ -2,10 +2,13 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.5.17 [June 27, 2013]
+ * Last changed in libpng 1.6.3 [July 18, 2013]
  * Maintained 1998-2013 Glenn Randers-Pehrson
- * Maintained 1996, 1997 Andreas Dilger
- * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * Maintained 1996, 1997 Andreas Dilger)
+ * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ * To the extent possible under law, the authors have waived
+ * all copyright and related or neighboring rights to this file.
+ * This work is published from: United States.
  */
 
 /* This is an example of how to use libpng to read and write PNG files.
@@ -13,8 +16,6 @@
  * read it, do so first.  This was designed to be a starting point of an
  * implementation.  This is not officially part of libpng, is hereby placed
  * in the public domain, and therefore does not require a copyright notice.
- * To the extent possible under law, the authors have waived all copyright and
- * related or neighboring rights to this file.
  *
  * This file does not currently compile, because it is missing certain
  * parts, like allocating memory to hold an image.  You will have to
@@ -23,11 +24,192 @@
  * see also the programs in the contrib directory.
  */
 
-#define _POSIX_SOURCE 1  /* libpng and zlib are POSIX-compliant.  You may
-                          * change this if your application uses non-POSIX
-                          * extensions. */
+/* The simple, but restricted, approach to reading a PNG file or data stream
+ * just requires two function calls, as in the following complete program.
+ * Writing a file just needs one function call, so long as the data has an
+ * appropriate layout.
+ *
+ * The following code reads PNG image data from a file and writes it, in a
+ * potentially new format, to a new file.  While this code will compile there is
+ * minimal (insufficient) error checking; for a more realistic version look at
+ * contrib/examples/pngtopng.c
+ */
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <png.h>
+#include <zlib.h>
 
-#include "png.h"
+int main(int argc, const char **argv)
+{
+   if (argc == 3)
+   {
+      png_image image; /* The control structure used by libpng */
+
+      /* Initialize the 'png_image' structure. */
+      memset(&image, 0, (sizeof image));
+      image.version = PNG_IMAGE_VERSION;
+
+      /* The first argument is the file to read: */
+      if (png_image_begin_read_from_file(&image, argv[1]))
+      {
+         png_bytep buffer;
+
+         /* Set the format in which to read the PNG file; this code chooses a
+          * simple sRGB format with a non-associated alpha channel, adequate to
+          * store most images.
+          */
+         image.format = PNG_FORMAT_RGBA;
+
+         /* Now allocate enough memory to hold the image in this format; the
+          * PNG_IMAGE_SIZE macro uses the information about the image (width,
+          * height and format) stored in 'image'.
+          */
+         buffer = malloc(PNG_IMAGE_SIZE(image));
+
+         /* If enough memory was available read the image in the desired format
+          * then write the result out to the new file.  'background' is not
+          * necessary when reading the image because the alpha channel is
+          * preserved; if it were to be removed, for example if we requested
+          * PNG_FORMAT_RGB, then either a solid background color would have to
+          * be supplied or the output buffer would have to be initialized to the
+          * actual background of the image.
+          *
+          * The fourth argument to png_image_finish_read is the 'row_stride' -
+          * this is the number of components allocated for the image in each
+          * row.  It has to be at least as big as the value returned by
+          * PNG_IMAGE_ROW_STRIDE, but if you just allocate space for the
+          * default, minimum, size using PNG_IMAGE_SIZE as above you can pass
+          * zero.
+          *
+          * The final argument is a pointer to a buffer for the colormap;
+          * colormaps have exactly the same format as a row of image pixels (so
+          * you choose what format to make the colormap by setting
+          * image.format).  A colormap is only returned if
+          * PNG_FORMAT_FLAG_COLORMAP is also set in image.format, so in this
+          * case NULL is passed as the final argument.  If you do want to force
+          * all images into an index/color-mapped format then you can use:
+          *
+          *    PNG_IMAGE_COLORMAP_SIZE(image)
+          *
+          * to find the maximum size of the colormap in bytes.
+          */
+         if (buffer != NULL &&
+            png_image_finish_read(&image, NULL/*background*/, buffer,
+               0/*row_stride*/, NULL/*colormap*/))
+         {
+            /* Now write the image out to the second argument.  In the write
+             * call 'convert_to_8bit' allows 16-bit data to be squashed down to
+             * 8 bits; this isn't necessary here because the original read was
+             * to the 8-bit format.
+             */
+            if (png_image_write_to_file(&image, argv[2], 0/*convert_to_8bit*/,
+               buffer, 0/*row_stride*/, NULL/*colormap*/))
+            {
+               /* The image has been written successfully. */
+               exit(0);
+            }
+         }
+
+         else
+         {
+            /* Calling png_free_image is optional unless the simplified API was
+             * not run to completion.  In this case if there wasn't enough
+             * memory for 'buffer' we didn't complete the read, so we must free
+             * the image:
+             */
+            if (buffer == NULL)
+               png_free_image(&image);
+
+            else
+               free(buffer);
+      }
+
+      /* Something went wrong reading or writing the image.  libpng stores a
+       * textual message in the 'png_image' structure:
+       */
+      fprintf(stderr, "pngtopng: error: %s\n", image.message);
+      exit (1);
+   }
+
+   fprintf(stderr, "pngtopng: usage: pngtopng input-file output-file\n");
+   exit(1);
+}
+
+/* That's it ;-)  Of course you probably want to do more with PNG files than
+ * just converting them all to 32-bit RGBA PNG files; you can do that between
+ * the call to png_image_finish_read and png_image_write_to_file.  You can also
+ * ask for the image data to be presented in a number of different formats.  You
+ * do this by simply changing the 'format' parameter set before allocating the
+ * buffer.
+ *
+ * The format parameter consists of five flags that define various aspects of
+ * the image, you can simply add these together to get the format or you can use
+ * one of the predefined macros from png.h (as above):
+ *
+ * PNG_FORMAT_FLAG_COLOR: if set the image will have three color components per
+ *    pixel (red, green and blue), if not set the image will just have one
+ *    luminance (grayscale) component.
+ *
+ * PNG_FORMAT_FLAG_ALPHA: if set each pixel in the image will have an additional
+ *    alpha value; a linear value that describes the degree the image pixel
+ *    covers (overwrites) the contents of the existing pixel on the display.
+ *
+ * PNG_FORMAT_FLAG_LINEAR: if set the components of each pixel will be returned
+ *    as a series of 16-bit linear values, if not set the components will be
+ *    returned as a series of 8-bit values encoded according to the 'sRGB'
+ *    standard.  The 8-bit format is the normal format for images intended for
+ *    direct display, because almost all display devices do the inverse of the
+ *    sRGB transformation to the data they receive.  The 16-bit format is more
+ *    common for scientific data and image data that must be further processed;
+ *    because it is linear simple math can be done on the component values.
+ *    Regardless of the setting of this flag the alpha channel is always linear,
+ *    although it will be 8 bits or 16 bits wide as specified by the flag.
+ *
+ * PNG_FORMAT_FLAG_BGR: if set the components of a color pixel will be returned
+ *    in the order blue, then green, then red.  If not set the pixel components
+ *    are in the order red, then green, then blue.
+ *
+ * PNG_FORMAT_FLAG_AFIRST: if set the alpha channel (if present) precedes the
+ *    color or grayscale components.  If not set the alpha channel follows the
+ *    components.
+ *
+ * You do not have to read directly from a file.  You can read from memory or,
+ * on systems that support it, from a <stdio.h> FILE*.  This is controlled by
+ * the particular png_image_read_from_ function you call at the start.  Likewise
+ * on write you can write to a FILE* if your system supports it.  Check the
+ * macro PNG_STDIO_SUPPORTED to see if stdio support has been included in your
+ * libpng build.
+ *
+ * If you read 16-bit (PNG_FORMAT_FLAG_LINEAR) data you may need to write it in
+ * the 8-bit format for display.  You do this by setting the convert_to_8bit
+ * flag to 'true'.
+ *
+ * Don't repeatedly convert between the 8-bit and 16-bit forms.  There is
+ * significant data loss when 16-bit data is converted to the 8-bit encoding and
+ * the current libpng implementation of convertion to 16-bit is also
+ * significantly lossy.  The latter will be fixed in the future, but the former
+ * is unavoidable - the 8-bit format just doesn't have enough resolution.
+ */
+
+/* If your program needs more information from the PNG data it reads, or if you
+ * need to do more complex transformations, or minimise transformations, on the
+ * data you read, then you must use one of the several lower level libpng
+ * interfaces.
+ *
+ * All these interfaces require that you do your own error handling - your
+ * program must be able to arrange for control to return to your own code any
+ * time libpng encounters a problem.  There are several ways to do this, but the
+ * standard way is to use the ANSI-C (C90) <setjmp.h> interface to establish a
+ * return point within your own code.  You must do this if you do not use the
+ * simplified interface (above).
+ *
+ * The first step is to include the header files you need, including the libpng
+ * header file.  Include any standard headers and feature test macros your
+ * program requires before including png.h:
+ */
+#include <png.h>
 
  /* The png_jmpbuf() macro, used in error handling, became available in
   * libpng version 1.0.6.  If you want to be able to run your code with older
@@ -549,7 +731,7 @@ row_callback(png_structp png_ptr, png_bytep new_row,
     * png_progressive_combine_row() passing in the new row and the
     * old row, as demonstrated above.  You can call this function for
     * NULL rows (it will just return) and for non-interlaced images
-    * (it just does the png_memcpy for you) if it will make the code
+    * (it just does the memcpy for you) if it will make the code
     * easier.  Thus, you can just do this for all cases:
     */
 
@@ -664,7 +846,7 @@ void write_png(char *file_name /* , ... other image information ... */)
 
    /* Set the palette if there is one.  REQUIRED for indexed-color images */
    palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
-             * png_sizeof(png_color));
+             * (sizeof (png_color)));
    /* ... Set palette colors ... */
    png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
    /* You must not free palette here, because png_set_PLTE only makes a link to
@@ -805,7 +987,7 @@ void write_png(char *file_name /* , ... other image information ... */)
 
    png_bytep row_pointers[height];
 
-   if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+   if (height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
      png_error (png_ptr, "Image is too tall to process in memory");
 
    /* Set up pointers into your "image" byte array */

install-sh

@@ -1,527 +0,0 @@
-#!/bin/sh
-# install - install a program, script, or datafile
-
-scriptversion=2011-11-20.07; # UTC
-
-# This originates from X11R5 (mit/util/scripts/install.sh), which was
-# later released in X11R6 (xc/config/util/install.sh) with the
-# following copyright and license.
-#
-# Copyright (C) 1994 X Consortium
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to
-# deal in the Software without restriction, including without limitation the
-# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
-# sell copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-# X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
-# AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNEC-
-# TION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-#
-# Except as contained in this notice, the name of the X Consortium shall not
-# be used in advertising or otherwise to promote the sale, use or other deal-
-# ings in this Software without prior written authorization from the X Consor-
-# tium.
-#
-#
-# FSF changes to this file are in the public domain.
-#
-# Calling this script install-sh is preferred over install.sh, to prevent
-# 'make' implicit rules from creating a file called install from it
-# when there is no Makefile.
-#
-# This script is compatible with the BSD install script, but was written
-# from scratch.
-
-nl='
-'
-IFS=" ""	$nl"
-
-# set DOITPROG to echo to test this script
-
-# Don't use :- since 4.3BSD and earlier shells don't like it.
-doit=${DOITPROG-}
-if test -z "$doit"; then
-  doit_exec=exec
-else
-  doit_exec=$doit
-fi
-
-# Put in absolute file names if you don't have them in your path;
-# or use environment vars.
-
-chgrpprog=${CHGRPPROG-chgrp}
-chmodprog=${CHMODPROG-chmod}
-chownprog=${CHOWNPROG-chown}
-cmpprog=${CMPPROG-cmp}
-cpprog=${CPPROG-cp}
-mkdirprog=${MKDIRPROG-mkdir}
-mvprog=${MVPROG-mv}
-rmprog=${RMPROG-rm}
-stripprog=${STRIPPROG-strip}
-
-posix_glob='?'
-initialize_posix_glob='
-  test "$posix_glob" != "?" || {
-    if (set -f) 2>/dev/null; then
-      posix_glob=
-    else
-      posix_glob=:
-    fi
-  }
-'
-
-posix_mkdir=
-
-# Desired mode of installed file.
-mode=0755
-
-chgrpcmd=
-chmodcmd=$chmodprog
-chowncmd=
-mvcmd=$mvprog
-rmcmd="$rmprog -f"
-stripcmd=
-
-src=
-dst=
-dir_arg=
-dst_arg=
-
-copy_on_change=false
-no_target_directory=
-
-usage="\
-Usage: $0 [OPTION]... [-T] SRCFILE DSTFILE
-   or: $0 [OPTION]... SRCFILES... DIRECTORY
-   or: $0 [OPTION]... -t DIRECTORY SRCFILES...
-   or: $0 [OPTION]... -d DIRECTORIES...
-
-In the 1st form, copy SRCFILE to DSTFILE.
-In the 2nd and 3rd, copy all SRCFILES to DIRECTORY.
-In the 4th, create DIRECTORIES.
-
-Options:
-     --help     display this help and exit.
-     --version  display version info and exit.
-
-  -c            (ignored)
-  -C            install only if different (preserve the last data modification time)
-  -d            create directories instead of installing files.
-  -g GROUP      $chgrpprog installed files to GROUP.
-  -m MODE       $chmodprog installed files to MODE.
-  -o USER       $chownprog installed files to USER.
-  -s            $stripprog installed files.
-  -t DIRECTORY  install into DIRECTORY.
-  -T            report an error if DSTFILE is a directory.
-
-Environment variables override the default commands:
-  CHGRPPROG CHMODPROG CHOWNPROG CMPPROG CPPROG MKDIRPROG MVPROG
-  RMPROG STRIPPROG
-"
-
-while test $# -ne 0; do
-  case $1 in
-    -c) ;;
-
-    -C) copy_on_change=true;;
-
-    -d) dir_arg=true;;
-
-    -g) chgrpcmd="$chgrpprog $2"
-	shift;;
-
-    --help) echo "$usage"; exit $?;;
-
-    -m) mode=$2
-	case $mode in
-	  *' '* | *'	'* | *'
-'*	  | *'*'* | *'?'* | *'['*)
-	    echo "$0: invalid mode: $mode" >&2
-	    exit 1;;
-	esac
-	shift;;
-
-    -o) chowncmd="$chownprog $2"
-	shift;;
-
-    -s) stripcmd=$stripprog;;
-
-    -t) dst_arg=$2
-	# Protect names problematic for 'test' and other utilities.
-	case $dst_arg in
-	  -* | [=\(\)!]) dst_arg=./$dst_arg;;
-	esac
-	shift;;
-
-    -T) no_target_directory=true;;
-
-    --version) echo "$0 $scriptversion"; exit $?;;
-
-    --)	shift
-	break;;
-
-    -*)	echo "$0: invalid option: $1" >&2
-	exit 1;;
-
-    *)  break;;
-  esac
-  shift
-done
-
-if test $# -ne 0 && test -z "$dir_arg$dst_arg"; then
-  # When -d is used, all remaining arguments are directories to create.
-  # When -t is used, the destination is already specified.
-  # Otherwise, the last argument is the destination.  Remove it from $@.
-  for arg
-  do
-    if test -n "$dst_arg"; then
-      # $@ is not empty: it contains at least $arg.
-      set fnord "$@" "$dst_arg"
-      shift # fnord
-    fi
-    shift # arg
-    dst_arg=$arg
-    # Protect names problematic for 'test' and other utilities.
-    case $dst_arg in
-      -* | [=\(\)!]) dst_arg=./$dst_arg;;
-    esac
-  done
-fi
-
-if test $# -eq 0; then
-  if test -z "$dir_arg"; then
-    echo "$0: no input file specified." >&2
-    exit 1
-  fi
-  # It's OK to call 'install-sh -d' without argument.
-  # This can happen when creating conditional directories.
-  exit 0
-fi
-
-if test -z "$dir_arg"; then
-  do_exit='(exit $ret); exit $ret'
-  trap "ret=129; $do_exit" 1
-  trap "ret=130; $do_exit" 2
-  trap "ret=141; $do_exit" 13
-  trap "ret=143; $do_exit" 15
-
-  # Set umask so as not to create temps with too-generous modes.
-  # However, 'strip' requires both read and write access to temps.
-  case $mode in
-    # Optimize common cases.
-    *644) cp_umask=133;;
-    *755) cp_umask=22;;
-
-    *[0-7])
-      if test -z "$stripcmd"; then
-	u_plus_rw=
-      else
-	u_plus_rw='% 200'
-      fi
-      cp_umask=`expr '(' 777 - $mode % 1000 ')' $u_plus_rw`;;
-    *)
-      if test -z "$stripcmd"; then
-	u_plus_rw=
-      else
-	u_plus_rw=,u+rw
-      fi
-      cp_umask=$mode$u_plus_rw;;
-  esac
-fi
-
-for src
-do
-  # Protect names problematic for 'test' and other utilities.
-  case $src in
-    -* | [=\(\)!]) src=./$src;;
-  esac
-
-  if test -n "$dir_arg"; then
-    dst=$src
-    dstdir=$dst
-    test -d "$dstdir"
-    dstdir_status=$?
-  else
-
-    # Waiting for this to be detected by the "$cpprog $src $dsttmp" command
-    # might cause directories to be created, which would be especially bad
-    # if $src (and thus $dsttmp) contains '*'.
-    if test ! -f "$src" && test ! -d "$src"; then
-      echo "$0: $src does not exist." >&2
-      exit 1
-    fi
-
-    if test -z "$dst_arg"; then
-      echo "$0: no destination specified." >&2
-      exit 1
-    fi
-    dst=$dst_arg
-
-    # If destination is a directory, append the input filename; won't work
-    # if double slashes aren't ignored.
-    if test -d "$dst"; then
-      if test -n "$no_target_directory"; then
-	echo "$0: $dst_arg: Is a directory" >&2
-	exit 1
-      fi
-      dstdir=$dst
-      dst=$dstdir/`basename "$src"`
-      dstdir_status=0
-    else
-      # Prefer dirname, but fall back on a substitute if dirname fails.
-      dstdir=`
-	(dirname "$dst") 2>/dev/null ||
-	expr X"$dst" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
-	     X"$dst" : 'X\(//\)[^/]' \| \
-	     X"$dst" : 'X\(//\)$' \| \
-	     X"$dst" : 'X\(/\)' \| . 2>/dev/null ||
-	echo X"$dst" |
-	    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
-		   s//\1/
-		   q
-		 }
-		 /^X\(\/\/\)[^/].*/{
-		   s//\1/
-		   q
-		 }
-		 /^X\(\/\/\)$/{
-		   s//\1/
-		   q
-		 }
-		 /^X\(\/\).*/{
-		   s//\1/
-		   q
-		 }
-		 s/.*/./; q'
-      `
-
-      test -d "$dstdir"
-      dstdir_status=$?
-    fi
-  fi
-
-  obsolete_mkdir_used=false
-
-  if test $dstdir_status != 0; then
-    case $posix_mkdir in
-      '')
-	# Create intermediate dirs using mode 755 as modified by the umask.
-	# This is like FreeBSD 'install' as of 1997-10-28.
-	umask=`umask`
-	case $stripcmd.$umask in
-	  # Optimize common cases.
-	  *[2367][2367]) mkdir_umask=$umask;;
-	  .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
-
-	  *[0-7])
-	    mkdir_umask=`expr $umask + 22 \
-	      - $umask % 100 % 40 + $umask % 20 \
-	      - $umask % 10 % 4 + $umask % 2
-	    `;;
-	  *) mkdir_umask=$umask,go-w;;
-	esac
-
-	# With -d, create the new directory with the user-specified mode.
-	# Otherwise, rely on $mkdir_umask.
-	if test -n "$dir_arg"; then
-	  mkdir_mode=-m$mode
-	else
-	  mkdir_mode=
-	fi
-
-	posix_mkdir=false
-	case $umask in
-	  *[123567][0-7][0-7])
-	    # POSIX mkdir -p sets u+wx bits regardless of umask, which
-	    # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
-	    ;;
-	  *)
-	    tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
-	    trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
-
-	    if (umask $mkdir_umask &&
-		exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
-	    then
-	      if test -z "$dir_arg" || {
-		   # Check for POSIX incompatibilities with -m.
-		   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
-		   # other-writable bit of parent directory when it shouldn't.
-		   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
-		   ls_ld_tmpdir=`ls -ld "$tmpdir"`
-		   case $ls_ld_tmpdir in
-		     d????-?r-*) different_mode=700;;
-		     d????-?--*) different_mode=755;;
-		     *) false;;
-		   esac &&
-		   $mkdirprog -m$different_mode -p -- "$tmpdir" && {
-		     ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
-		     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
-		   }
-		 }
-	      then posix_mkdir=:
-	      fi
-	      rmdir "$tmpdir/d" "$tmpdir"
-	    else
-	      # Remove any dirs left behind by ancient mkdir implementations.
-	      rmdir ./$mkdir_mode ./-p ./-- 2>/dev/null
-	    fi
-	    trap '' 0;;
-	esac;;
-    esac
-
-    if
-      $posix_mkdir && (
-	umask $mkdir_umask &&
-	$doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir"
-      )
-    then :
-    else
-
-      # The umask is ridiculous, or mkdir does not conform to POSIX,
-      # or it failed possibly due to a race condition.  Create the
-      # directory the slow way, step by step, checking for races as we go.
-
-      case $dstdir in
-	/*) prefix='/';;
-	[-=\(\)!]*) prefix='./';;
-	*)  prefix='';;
-      esac
-
-      eval "$initialize_posix_glob"
-
-      oIFS=$IFS
-      IFS=/
-      $posix_glob set -f
-      set fnord $dstdir
-      shift
-      $posix_glob set +f
-      IFS=$oIFS
-
-      prefixes=
-
-      for d
-      do
-	test X"$d" = X && continue
-
-	prefix=$prefix$d
-	if test -d "$prefix"; then
-	  prefixes=
-	else
-	  if $posix_mkdir; then
-	    (umask=$mkdir_umask &&
-	     $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
-	    # Don't fail if two instances are running concurrently.
-	    test -d "$prefix" || exit 1
-	  else
-	    case $prefix in
-	      *\'*) qprefix=`echo "$prefix" | sed "s/'/'\\\\\\\\''/g"`;;
-	      *) qprefix=$prefix;;
-	    esac
-	    prefixes="$prefixes '$qprefix'"
-	  fi
-	fi
-	prefix=$prefix/
-      done
-
-      if test -n "$prefixes"; then
-	# Don't fail if two instances are running concurrently.
-	(umask $mkdir_umask &&
-	 eval "\$doit_exec \$mkdirprog $prefixes") ||
-	  test -d "$dstdir" || exit 1
-	obsolete_mkdir_used=true
-      fi
-    fi
-  fi
-
-  if test -n "$dir_arg"; then
-    { test -z "$chowncmd" || $doit $chowncmd "$dst"; } &&
-    { test -z "$chgrpcmd" || $doit $chgrpcmd "$dst"; } &&
-    { test "$obsolete_mkdir_used$chowncmd$chgrpcmd" = false ||
-      test -z "$chmodcmd" || $doit $chmodcmd $mode "$dst"; } || exit 1
-  else
-
-    # Make a couple of temp file names in the proper directory.
-    dsttmp=$dstdir/_inst.$$_
-    rmtmp=$dstdir/_rm.$$_
-
-    # Trap to clean up those temp files at exit.
-    trap 'ret=$?; rm -f "$dsttmp" "$rmtmp" && exit $ret' 0
-
-    # Copy the file name to the temp name.
-    (umask $cp_umask && $doit_exec $cpprog "$src" "$dsttmp") &&
-
-    # and set any options; do chmod last to preserve setuid bits.
-    #
-    # If any of these fail, we abort the whole thing.  If we want to
-    # ignore errors from any of these, just make sure not to ignore
-    # errors from the above "$doit $cpprog $src $dsttmp" command.
-    #
-    { test -z "$chowncmd" || $doit $chowncmd "$dsttmp"; } &&
-    { test -z "$chgrpcmd" || $doit $chgrpcmd "$dsttmp"; } &&
-    { test -z "$stripcmd" || $doit $stripcmd "$dsttmp"; } &&
-    { test -z "$chmodcmd" || $doit $chmodcmd $mode "$dsttmp"; } &&
-
-    # If -C, don't bother to copy if it wouldn't change the file.
-    if $copy_on_change &&
-       old=`LC_ALL=C ls -dlL "$dst"	2>/dev/null` &&
-       new=`LC_ALL=C ls -dlL "$dsttmp"	2>/dev/null` &&
-
-       eval "$initialize_posix_glob" &&
-       $posix_glob set -f &&
-       set X $old && old=:$2:$4:$5:$6 &&
-       set X $new && new=:$2:$4:$5:$6 &&
-       $posix_glob set +f &&
-
-       test "$old" = "$new" &&
-       $cmpprog "$dst" "$dsttmp" >/dev/null 2>&1
-    then
-      rm -f "$dsttmp"
-    else
-      # Rename the file to the real destination.
-      $doit $mvcmd -f "$dsttmp" "$dst" 2>/dev/null ||
-
-      # The rename failed, perhaps because mv can't rename something else
-      # to itself, or perhaps because mv is so ancient that it does not
-      # support -f.
-      {
-	# Now remove or move aside any old file at destination location.
-	# We try this two ways since rm can't unlink itself on some
-	# systems and the destination file might be busy for other
-	# reasons.  In this case, the final cleanup might fail but the new
-	# file should still install successfully.
-	{
-	  test ! -f "$dst" ||
-	  $doit $rmcmd -f "$dst" 2>/dev/null ||
-	  { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
-	    { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
-	  } ||
-	  { echo "$0: cannot unlink or rename $dst" >&2
-	    (exit 1); exit 1
-	  }
-	} &&
-
-	# Now rename the file to the real destination.
-	$doit $mvcmd "$dsttmp" "$dst"
-      }
-    fi || exit 1
-
-    trap '' 0
-  fi
-done
-
-# Local variables:
-# eval: (add-hook 'write-file-hooks 'time-stamp)
-# time-stamp-start: "scriptversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
-# time-stamp-time-zone: "UTC"
-# time-stamp-end: "; # UTC"
-# End:

libpng-manual.txt

@@ -1,6 +1,6 @@
-Libpng-manual.txt - A description on how to use and modify libpng
+libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.5.18beta01 - August 21, 2013
+ libpng version 1.6.8rc02 - December 14, 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 1.5.18beta01 - August 21, 2013
+ libpng versions 0.97, January 1998, through 1.6.8rc02 - December 14, 2013
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2013 Glenn Randers-Pehrson
 
@@ -28,6 +28,25 @@ Libpng-manual.txt - A description on how to use and modify libpng
  Copyright (c) 1995, 1996 Frank J. T. Wojcik
  December 18, 1995 & January 20, 1996
 
+ TABLE OF CONTENTS
+
+    I. Introduction
+   II. Structures
+  III. Reading
+   IV. Writing
+    V. Simplified API
+   VI. Modifying/Customizing libpng
+  VII. MNG support
+ VIII. Changes to Libpng from version 0.88
+   IX. Changes to Libpng from version 1.0.x to 1.2.x
+    X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+   XI. Changes to Libpng from version 1.4.x to 1.5.x
+  XII. Changes to Libpng from version 1.5.x to 1.6.x
+ XIII. Detecting libpng
+  XIV. Source code repository
+   XV. Coding style
+  XVI. Y2K Compliance in libpng
+
 I. Introduction
 
 This file describes how to use and modify the PNG reference library
@@ -506,8 +525,14 @@ you can retrieve with
     png_get_user_chunk_ptr(png_ptr);
 
 If you call the png_set_read_user_chunk_fn() function, then all unknown
-chunks will be saved when read, in case your callback function will need
-one or more of them.
+chunks which the callback does not handle will be saved when read.  You can
+cause them to be discarded by returning '1' ("handled") instead of '0'.  This
+behavior will change in libpng 1.7 and the default handling set by the
+png_set_keep_unknown_chunks() function, described below, will be used when the
+callback returns 0.  If you want the existing behavior you should set the global
+default to PNG_HANDLE_CHUNK_IF_SAFE now; this is compatible with all current
+versions of libpng and with 1.7.  Libpng 1.6 issues a warning if you keep the
+default, or PNG_HANDLE_CHUNK_NEVER, and the callback returns 0.
 
 At this point, you can set up a callback function that will be
 called after each row has been read, which you can use to control
@@ -550,6 +575,7 @@ chunk types. To change this, you can call:
 
     png_set_keep_unknown_chunks(png_ptr, keep,
         chunk_list, num_chunks);
+
     keep       - 0: default unknown chunk handling
                  1: ignore; do not keep
                  2: keep only if safe-to-copy
@@ -563,11 +589,16 @@ chunk types. To change this, you can call:
 
     chunk_list - list of chunks affected (a byte string,
                  five bytes per chunk, NULL or '\0' if
-                 num_chunks is 0)
+                 num_chunks is positive; ignored if
+                 numchunks <= 0).
 
     num_chunks - number of chunks affected; if 0, all
-                 unknown chunks are affected.  If nonzero,
-                 only the chunks in the list are affected
+                 unknown chunks are affected.  If positive,
+                 only the chunks in the list are affected,
+                 and if negative all unknown chunks and
+                 all known chunks except for the IHDR,
+                 PLTE, tRNS, IDAT, and IEND chunks are
+                 affected.
 
 Unknown chunks declared in this way will be saved as raw data onto a
 list of png_unknown_chunk structures.  If a chunk that is normally
@@ -600,19 +631,17 @@ callback function:
     ...
 
     #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
-      /* ignore all unknown chunks: */
-    #  if PNG_LIBPNG_VER < 10700
+      /* ignore all unknown chunks
+       * (use global setting "2" for libpng16 and earlier):
+       */
       png_set_keep_unknown_chunks(read_ptr, 2, NULL, 0);
-    #  else
-      png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0);
-    #  endif
 
       /* except for vpAg: */
       png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1);
 
       /* also ignore unused known chunks: */
       png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks,
-         (int)png_sizeof(unused_chunks)/5);
+         (int)(sizeof unused_chunks)/5);
     #endif
 
 User limits
@@ -687,7 +716,8 @@ assumes that the PNG data matches your system, to keep this default call:
 
 or you can use the fixed point equivalent:
 
-   png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma);
+   png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma,
+      PNG_FP_1/screen_gamma);
 
 If you don't know the gamma for your system it is probably 2.2 - a good
 approximation to the IEC standard for display systems (sRGB).  If images are
@@ -699,12 +729,15 @@ display driver, a few systems, including older Macs, change the response by
 default.  As of 1.5.4 three special values are available to handle common
 situations:
 
-   PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1
-                     standard.  This matches almost all systems.
-   PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6)
-                     Apple Macintosh system with the default settings.
-   PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the
-                     system expects data with no gamma encoding.
+   PNG_DEFAULT_sRGB: Indicates that the system conforms to the
+                     IEC 61966-2-1 standard.  This matches almost
+                     all systems.
+   PNG_GAMMA_MAC_18: Indicates that the system is an older
+                     (pre Mac OS 10.6) Apple Macintosh system with
+                     the default settings.
+   PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates
+                     that the system expects data with no gamma
+                     encoding.
 
 You would use the linear (unencoded) value if you need to process the pixel
 values further because this avoids the need to decode and re-encode each
@@ -721,11 +754,11 @@ Libpng only supports composing onto a single color (using png_set_background;
 see below).  Otherwise you must do the composition yourself and, in this case,
 you may need to call png_set_alpha_mode:
 
-    #if PNG_LIBPNG_VER >= 10504
-       png_set_alpha_mode(png_ptr, mode, screen_gamma);
-    #else
-       png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma);
-    #endif
+   #if PNG_LIBPNG_VER >= 10504
+      png_set_alpha_mode(png_ptr, mode, screen_gamma);
+   #else
+      png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma);
+   #endif
 
 The screen_gamma value is the same as the argument to png_set_gamma; however,
 how it affects the output depends on the mode.  png_set_alpha_mode() sets the
@@ -960,7 +993,7 @@ where row_pointers is an array of pointers to the pixel data for each row:
 If you know your image size and pixel size ahead of time, you can allocate
 row_pointers prior to calling png_read_png() with
 
-   if (height > PNG_UINT_32_MAX/png_sizeof(png_byte))
+   if (height > PNG_UINT_32_MAX/(sizeof (png_byte)))
       png_error (png_ptr,
           "Image is too tall to process in memory");
 
@@ -969,7 +1002,7 @@ row_pointers prior to calling png_read_png() with
           "Image is too wide to process in memory");
 
    row_pointers = png_malloc(png_ptr,
-       height*png_sizeof(png_bytep));
+       height*(sizeof (png_bytep)));
 
    for (int i=0; i<height, i++)
       row_pointers[i]=NULL;  /* security precaution */
@@ -1131,7 +1164,11 @@ pointer into the info_ptr is returned for any complex types.
 The colorspace data from gAMA, cHRM, sRGB, iCCP, and sBIT chunks
 is simply returned to give the application information about how the
 image was encoded.  Libpng itself only does transformations using the file
-gamma when combining semitransparent pixels with the background color.
+gamma when combining semitransparent pixels with the background color, and,
+since libpng-1.6.0, when converting between 8-bit sRGB and 16-bit linear pixels
+within the simplified API.  Libpng also uses the file gamma when converting
+RGB to gray, beginning with libpng-1.0.5, if the application calls
+png_set_rgb_to_gray()).
 
     png_get_PLTE(png_ptr, info_ptr, &palette,
                      &num_palette);
@@ -1144,7 +1181,7 @@ gamma when combining semitransparent pixels with the background color.
     png_get_gAMA(png_ptr, info_ptr, &file_gamma);
     png_get_gAMA_fixed(png_ptr, info_ptr, &int_file_gamma);
 
-    file_gamma     - the gamma at which the file was
+    file_gamma     - the gamma at which the file is
                      written (PNG_INFO_gAMA)
 
     int_file_gamma - 100,000 times the gamma at which the
@@ -1152,14 +1189,17 @@ gamma when combining semitransparent pixels with the background color.
 
     png_get_cHRM(png_ptr, info_ptr,  &white_x, &white_y, &red_x,
                      &red_y, &green_x, &green_y, &blue_x, &blue_y)
-    png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, &green_X,
-                     &green_Y, &green_Z, &blue_X, &blue_Y, &blue_Z)
-    png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, &int_white_y,
-                     &int_red_x, &int_red_y, &int_green_x, &int_green_y,
-                     &int_blue_x, &int_blue_y)
+    png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z,
+                     &green_X, &green_Y, &green_Z, &blue_X, &blue_Y,
+                     &blue_Z)
+    png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x,
+                     &int_white_y, &int_red_x, &int_red_y,
+                     &int_green_x, &int_green_y, &int_blue_x,
+                     &int_blue_y)
     png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y,
-                     &int_red_Z, &int_green_X, &int_green_Y, &int_green_Z,
-                     &int_blue_X, &int_blue_Y, &int_blue_Z)
+                     &int_red_Z, &int_green_X, &int_green_Y,
+                     &int_green_Z, &int_blue_X, &int_blue_Y,
+                     &int_blue_Z)
 
     {white,red,green,blue}_{x,y}
                      A color space encoding specified using the
@@ -1167,11 +1207,12 @@ gamma when combining semitransparent pixels with the background color.
                      white point. (PNG_INFO_cHRM)
 
     {red,green,blue}_{X,Y,Z}
-                     A color space encoding specified using the encoding end
-                     points - the CIE tristimulus specification of the intended
-                     color of the red, green and blue channels in the PNG RGB
-                     data.  The white point is simply the sum of the three end
-                     points. (PNG_INFO_cHRM)
+                     A color space encoding specified using the
+                     encoding end points - the CIE tristimulus
+                     specification of the intended color of the red,
+                     green and blue channels in the PNG RGB data.
+                     The white point is simply the sum of the three
+                     end points. (PNG_INFO_cHRM)
 
     png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
 
@@ -2528,6 +2569,20 @@ You can #define PNG_ABORT() to a function that does something
 more useful than abort(), as long as your function does not
 return.
 
+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, 0);
+
+If the error is ignored, or if png_benign_error() treats it as a warning,
+any invalid pixels are written as-is by the encoder, resulting in an
+invalid PNG datastream as output.  In this case the application is
+responsible for ensuring that the pixel indexes are in range when it writes
+a PLTE chunk with fewer entries than the bit depth would allow.
+
 Now you need to set up the output code.  The default for libpng is to
 use the C function fwrite().  If you use this, you will need to pass a
 valid FILE * in the function png_init_io().  Be sure that the file is
@@ -3030,8 +3085,9 @@ tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
 although this isn't a requirement.  Unlike the tIME chunk, the
 "Creation Time" tEXt chunk is not expected to be automatically changed
 by the software.  To facilitate the use of RFC 1123 dates, a function
-png_convert_to_rfc1123(png_ptr, png_timep) is provided to convert
-from PNG time to an RFC 1123 format string.
+png_convert_to_rfc1123_buffer(png_ptr, buffer, png_timep) is provided to
+convert from PNG time to an RFC 1123 format string.  The caller must provide
+a writeable buffer of at least 29 bytes.
 
 Writing unknown chunks
 
@@ -3062,9 +3118,11 @@ Here is an example of writing two private chunks, prVt and miNE:
     /* Needed because miNE is not safe-to-copy */
     png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS,
        (png_bytep) "miNE", 1);
-    /* Deal with unknown chunk location bug in 1.5.x and earlier */
-    png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR);
-    png_set_unknown_chunk_location(png, info, 1, PNG_AFTER_IDAT);
+    # if PNG_LIBPNG_VER < 10600
+      /* Deal with unknown chunk location bug in 1.5.x and earlier */
+      png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR);
+      png_set_unknown_chunk_location(png, info, 1, PNG_AFTER_IDAT);
+    # endif
     # if PNG_LIBPNG_VER < 10500
       /* PNG_AFTER_IDAT writes two copies of the chunk prior to libpng-1.5.0,
        * one before IDAT and another after IDAT, so don't use it; only use
@@ -3471,7 +3529,364 @@ if you transfer responsibility for free'ing text_ptr from libpng to your
 application, your application must not separately free those members.
 For a more compact example of writing a PNG image, see the file example.c.
 
-V. Modifying/Customizing libpng:
+V. Simplified API
+
+The simplified API, which became available in libpng-1.6.0, hides the details
+of both libpng and the PNG file format itself.
+It allows PNG files to be read into a very limited number of
+in-memory bitmap formats or to be written from the same formats.  If these
+formats do not accommodate your needs then you can, and should, use the more
+sophisticated APIs above - these support a wide variety of in-memory formats
+and a wide variety of sophisticated transformations to those formats as well
+as a wide variety of APIs to manipulate ancilliary information.
+
+To read a PNG file using the simplified API:
+
+  1) Declare a 'png_image' structure (see below) on the
+     stack and memset() it to all zero.
+
+  2) Call the appropriate png_image_begin_read... function.
+
+  3) Set the png_image 'format' member to the required
+     format and allocate a buffer for the image.
+
+  4) Call png_image_finish_read to read the image into
+     your buffer.
+
+There are no restrictions on the format of the PNG input itself; all valid
+color types, bit depths, and interlace methods are acceptable, and the
+input image is transformed as necessary to the requested in-memory format
+during the png_image_finish_read() step.
+
+To write a PNG file using the simplified API:
+
+  1) Declare a 'png_image' structure on the stack and memset()
+     it to all zero.
+
+  2) Initialize the members of the structure that describe the
+     image, setting the 'format' member to the format of the
+     image in memory.
+
+  3) Call the appropriate png_image_write... function with a
+     pointer to the image to write the PNG data.
+
+png_image is a structure that describes the in-memory format of an image
+when it is being read or define the in-memory format of an image that you
+need to write.  The "png_image" structure contains the following members:
+
+   png_uint_32  version Set to PNG_IMAGE_VERSION
+   png_uint_32  width   Image width in pixels (columns)
+   png_uint_32  height  Image height in pixels (rows)
+   png_uint_32  format  Image format as defined below
+   png_uint_32  flags   A bit mask containing informational flags
+   png_controlp opaque  Initialize to NULL, free with png_image_free
+   png_uint_32  colormap_entries; Number of entries in the color-map
+   png_uint_32  warning_or_error;
+   char         message[64];
+
+In the event of an error or warning the following field warning_or_error
+field will be set to a non-zero value and the 'message' field will contain
+a '\0' terminated string with the libpng error or warning message.  If both
+warnings and an error were encountered, only the error is recorded.  If there
+are multiple warnings, only the first one is recorded.
+
+The upper 30 bits of this value are reserved; the low two bits contain
+a two bit code such that a value more than 1 indicates a failure in the API
+just called:
+
+   0 - no warning or error
+   1 - warning
+   2 - error
+   3 - error preceded by warning
+
+The pixels (samples) of the image have one to four channels whose components
+have original values in the range 0 to 1.0:
+
+  1: A single gray or luminance channel (G).
+  2: A gray/luminance channel and an alpha channel (GA).
+  3: Three red, green, blue color channels (RGB).
+  4: Three color channels and an alpha channel (RGBA).
+
+The channels are encoded in one of two ways:
+
+  a) As a small integer, value 0..255, contained in a single byte.  For the
+alpha channel the original value is simply value/255.  For the color or
+luminance channels the value is encoded according to the sRGB specification
+and matches the 8-bit format expected by typical display devices.
+
+The color/gray channels are not scaled (pre-multiplied) by the alpha
+channel and are suitable for passing to color management software.
+
+  b) As a value in the range 0..65535, contained in a 2-byte integer.  All
+channels can be converted to the original value by dividing by 65535; all
+channels are linear.  Color channels use the RGB encoding (RGB end-points) of
+the sRGB specification.  This encoding is identified by the
+PNG_FORMAT_FLAG_LINEAR flag below.
+
+When an alpha channel is present it is expected to denote pixel coverage
+of the color or luminance channels and is returned as an associated alpha
+channel: the color/gray channels are scaled (pre-multiplied) by the alpha
+value.
+
+When a color-mapped image is used as a result of calling
+png_image_read_colormap or png_image_write_colormap the channels are encoded
+in the color-map and the descriptions above apply to the color-map entries.
+The image data is encoded as small integers, value 0..255, that index the
+entries in the color-map.  One integer (one byte) is stored for each pixel.
+
+PNG_FORMAT_*
+
+The #defines to be used in png_image::format.  Each #define identifies a
+particular layout of channel data and, if present, alpha values.  There are
+separate defines for each of the two channel encodings.
+
+A format is built up using single bit flag values.  Not all combinations are
+valid: use the bit flag values below for testing a format returned by the
+read APIs, but set formats from the derived values.
+
+When reading or writing color-mapped images the format should be set to the
+format of the entries in the color-map then png_image_{read,write}_colormap
+called to read or write the color-map and set the format correctly for the
+image data.  Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
+
+NOTE: libpng can be built with particular features disabled, if you see
+compiler errors because the definition of one of the following flags has been
+compiled out it is because libpng does not have the required support.  It is
+possible, however, for the libpng configuration to enable the format on just
+read or just write; in that case you may see an error at run time.  You can
+guard against this by checking for the definition of:
+
+   PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
+
+   PNG_FORMAT_FLAG_ALPHA    0x01 format with an alpha channel
+   PNG_FORMAT_FLAG_COLOR    0x02 color format: otherwise grayscale
+   PNG_FORMAT_FLAG_LINEAR   0x04 png_uint_16 channels else png_byte
+   PNG_FORMAT_FLAG_COLORMAP 0x08 libpng use only
+   PNG_FORMAT_FLAG_BGR      0x10 BGR colors, else order is RGB
+   PNG_FORMAT_FLAG_AFIRST   0x20 alpha channel comes first
+
+Supported formats are as follows.  Future versions of libpng may support more
+formats; for compatibility with older versions simply check if the format
+macro is defined using #ifdef.  These defines describe the in-memory layout
+of the components of the pixels of the image.
+
+First the single byte formats:
+
+   PNG_FORMAT_GRAY 0
+   PNG_FORMAT_GA   PNG_FORMAT_FLAG_ALPHA
+   PNG_FORMAT_AG   (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
+   PNG_FORMAT_RGB  PNG_FORMAT_FLAG_COLOR
+   PNG_FORMAT_BGR  (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
+   PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
+   PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
+   PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
+   PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
+
+Then the linear 2-byte formats.  When naming these "Y" is used to
+indicate a luminance (gray) channel.  The component order within the pixel
+is always the same - there is no provision for swapping the order of the
+components in the linear format.
+
+   PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
+   PNG_FORMAT_LINEAR_Y_ALPHA
+      (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
+   PNG_FORMAT_LINEAR_RGB
+      (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
+   PNG_FORMAT_LINEAR_RGB_ALPHA
+      (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|
+      PNG_FORMAT_FLAG_ALPHA)
+
+Color-mapped formats are obtained by calling png_image_{read,write}_colormap,
+as appropriate after setting png_image::format to the format of the color-map
+to be read or written.  Applications may check the value of
+PNG_FORMAT_FLAG_COLORMAP to see if they have called the colormap API.  The
+format of the color-map may be extracted using the following macro.
+
+   PNG_FORMAT_OF_COLORMAP(fmt) ((fmt) & ~PNG_FORMAT_FLAG_COLORMAP)
+
+PNG_IMAGE macros
+
+These are convenience macros to derive information from a png_image
+structure.  The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
+actual image sample values - either the entries in the color-map or the
+pixels in the image.  The PNG_IMAGE_PIXEL_ macros return corresponding values
+for the pixels and will always return 1 after a call to
+png_image_{read,write}_colormap.  The remaining macros return information
+about the rows in the image and the complete image.
+
+NOTE: All the macros that take a png_image::format parameter are compile time
+constants if the format parameter is, itself, a constant.  Therefore these
+macros can be used in array declarations and case labels where required.
+Similarly the macros are also pre-processor constants (sizeof is not used) so
+they can be used in #if tests.
+
+First the information about the samples.
+
+  PNG_IMAGE_SAMPLE_CHANNELS(fmt)
+    Returns the total number of channels in a given format: 1..4
+
+  PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)
+    Returns the size in bytes of a single component of a pixel or color-map
+    entry (as appropriate) in the image.
+
+  PNG_IMAGE_SAMPLE_SIZE(fmt)
+    This is the size of the sample data for one sample.  If the image is
+    color-mapped it is the size of one color-map entry (and image pixels are
+    one byte in size), otherwise it is the size of one image pixel.
+
+  PNG_IMAGE_COLORMAP_SIZE(fmt)
+   The size of the color-map required by the format; this is the size of the
+   color-map buffer passed to the png_image_{read,write}_colormap APIs, it is
+   a fixed number determined by the format so can easily be allocated on the
+   stack if necessary.
+
+#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
+   (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
+   /* The maximum size of the color-map required by the format expressed in a
+    * count of components.  This can be used to compile-time allocate a
+    * color-map:
+    *
+    * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
+    *
+    * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
+    *
+    * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+    * information from one of the png_image_begin_read_ APIs and dynamically
+    * allocate the required memory.
+    */
+
+
+Corresponding information about the pixels
+
+  PNG_IMAGE_PIXEL_(test,fmt)
+
+  PNG_IMAGE_PIXEL_CHANNELS(fmt)
+   The number of separate channels (components) in a pixel; 1 for a
+   color-mapped image.
+
+  PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
+   The size, in bytes, of each component in a pixel; 1 for a color-mapped
+   image.
+
+  PNG_IMAGE_PIXEL_SIZE(fmt)
+   The size, in bytes, of a complete pixel; 1 for a color-mapped image.
+
+Information about the whole row, or whole image
+
+  PNG_IMAGE_ROW_STRIDE(image)
+   Returns the total number of components in a single row of the image; this
+   is the minimum 'row stride', the minimum count of components between each
+   row.  For a color-mapped image this is the minimum number of bytes in a
+   row.
+
+  PNG_IMAGE_BUFFER_SIZE(image, row_stride)
+    Returns the size, in bytes, of an image buffer given a png_image and a row
+    stride - the number of components to leave space for in each row.
+
+  PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB == 0x01
+    This indicates the the RGB values of the in-memory bitmap do not
+    correspond to the red, green and blue end-points defined by sRGB.
+
+  PNG_IMAGE_FLAG_COLORMAP == 0x02
+    The PNG is color-mapped.  If this flag is set png_image_read_colormap
+    can be used without further loss of image information.  If it is not set
+    png_image_read_colormap will cause significant loss if the image has any
+
+READ APIs
+
+   The png_image passed to the read APIs must have been initialized by setting
+   the png_controlp field 'opaque' to NULL (or, better, memset the whole thing.)
+
+   int png_image_begin_read_from_file( png_imagep image,
+     const char *file_name)
+
+     The named file is opened for read and the image header
+     is filled in from the PNG header in the file.
+
+   int png_image_begin_read_from_stdio (png_imagep image,
+     FILE* file)
+
+      The PNG header is read from the stdio FILE object.
+
+   int png_image_begin_read_from_memory(png_imagep image,
+      png_const_voidp memory, png_size_t size)
+
+      The PNG header is read from the given memory buffer.
+
+   int png_image_finish_read(png_imagep image,
+      png_colorp background, void *buffer,
+      png_int_32 row_stride, void *colormap));
+
+      Finish reading the image into the supplied buffer and
+      clean up the png_image structure.
+
+      row_stride is the step, in png_byte or png_uint_16 units
+      as appropriate, between adjacent rows.  A positive stride
+      indicates that the top-most row is first in the buffer -
+      the normal top-down arrangement.  A negative stride
+      indicates that the bottom-most row is first in the buffer.
+
+      background need only be supplied if an alpha channel must
+      be removed from a png_byte format and the removal is to be
+      done by compositing on a solid color; otherwise it may be
+      NULL and any composition will be done directly onto the
+      buffer.  The value is an sRGB color to use for the
+      background, for grayscale output the green channel is used.
+
+      For linear output removing the alpha channel is always done
+      by compositing on black.
+
+   void png_image_free(png_imagep image)
+
+      Free any data allocated by libpng in image->opaque,
+      setting the pointer to NULL.  May be called at any time
+      after the structure is initialized.
+
+When the simplified API needs to convert between sRGB and linear colorspaces,
+the actual sRGB transfer curve defined in the sRGB specification (see the
+article at http://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
+approximation used elsewhere in libpng.
+
+WRITE APIS
+
+For write you must initialize a png_image structure to describe the image to
+be written:
+
+   version: must be set to PNG_IMAGE_VERSION
+   opaque: must be initialized to NULL
+   width: image width in pixels
+   height: image height in rows
+   format: the format of the data you wish to write
+   flags: set to 0 unless one of the defined flags applies; set
+      PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images
+      where the RGB values do not correspond to the colors in sRGB.
+   colormap_entries: set to the number of entries in the color-map (0 to 256)
+
+   int png_image_write_to_file, (png_imagep image,
+      const char *file, int convert_to_8bit, const void *buffer,
+      png_int_32 row_stride, const void *colormap));
+
+      Write the image to the named file.
+
+   int png_image_write_to_stdio(png_imagep image, FILE *file,
+      int convert_to_8_bit, const void *buffer,
+      png_int_32 row_stride, const void *colormap)
+
+      Write the image to the given (FILE*).
+
+With all write APIs if image is in one of the linear formats with
+(png_uint_16) data then setting convert_to_8_bit will cause the output to be
+a (png_byte) PNG gamma encoded according to the sRGB specification, otherwise
+a 16-bit linear encoded PNG file is written.
+
+With all APIs row_stride is handled as in the read APIs - it is the spacing
+from one row to the next in component sized units (float) and if negative
+indicates a bottom-up row layout in the buffer.
+
+Note that the write API does not support interlacing, sub-8-bit pixels,
+and indexed (paletted) images.
+
+VI. Modifying/Customizing libpng
 
 There are two issues here.  The first is changing how libpng does
 standard things like memory allocation, input/output, and error handling.
@@ -3605,6 +4020,18 @@ compiler documentation for more details.  For an alternative approach, you
 may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net),
 which is illustrated in pngvalid.c and in contrib/visupng.
 
+Beginning in libpng-1.4.0, the png_set_benign_errors() API became available.
+You can use this to handle certain errors (normally handled as errors)
+as warnings.
+
+    png_set_benign_errors (png_ptr, int allowed);
+
+    allowed: 0: treat png_benign_error() as an error.
+             1: treat png_benign_error() as a warning.
+
+As of libpng-1.6.0, the default condition is to treat benign errors as
+warnings while reading and as errors while writing.
+
 Custom chunks
 
 If you need to read or write custom chunks, you may need to get deeper
@@ -3893,7 +4320,18 @@ When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
 having level = 0 will be printed.  There aren't any such statements in
 this version of libpng, but if you insert some they will be printed.
 
-VI.  MNG support
+Prepending a prefix to exported symbols
+
+Starting with libpng-1.6.0, you can configure libpng (when using the
+"configure" script) to prefix all exported symbols by means of the
+configuration option "--with-libpng-prefix=FOO_", where FOO_ can be any
+string beginning with a letter and containing only uppercase
+and lowercase letters, digits, and the underscore (i.e., a C language
+identifier).  This creates a set of macros in pnglibconf.h, so this is
+transparent to applications; their function calls get transformed by
+the macros to use the modified names.
+
+VII.  MNG support
 
 The MNG specification (available at http://www.libpng.org/pub/mng) allows
 certain extensions to PNG for PNG images that are embedded in MNG datastreams.
@@ -3920,7 +4358,7 @@ or any other MNG chunks; your application must provide its own support for
 them.  You may wish to consider using libmng (available at
 http://www.libmng.com) instead.
 
-VII.  Changes to Libpng from version 0.88
+VIII.  Changes to Libpng from version 0.88
 
 It should be noted that versions of libpng later than 0.96 are not
 distributed by the original libpng author, Guy Schalnat, nor by
@@ -3972,7 +4410,7 @@ application:
 
    png_uint_32 application_vn = PNG_LIBPNG_VER;
 
-VIII.  Changes to Libpng from version 1.0.x to 1.2.x
+IX.  Changes to Libpng from version 1.0.x to 1.2.x
 
 Support for user memory management was enabled by default.  To
 accomplish this, the functions png_create_read_struct_2(),
@@ -4069,7 +4507,7 @@ which also expands tRNS to alpha was replaced with
     png_set_expand_gray_1_2_4_to_8()
 which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
 
-IX.  Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+X.  Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
 
 Private libpng prototypes and macro definitions were moved from
 png.h and pngconf.h into a new pngpriv.h header file.
@@ -4124,8 +4562,8 @@ png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(),
 png_set_asm_flags(), and png_mmx_supported()
 
 We removed the obsolete png_check_sig(), png_memcpy_check(), and
-png_memset_check() functions.  Instead use !png_sig_cmp(), png_memcpy(),
-and png_memset(), respectively.
+png_memset_check() functions.  Instead use !png_sig_cmp(), memcpy(),
+and memset(), respectively.
 
 The function png_set_gray_1_2_4_to_8() was removed. It has been
 deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
@@ -4179,20 +4617,29 @@ was renamed to PNG_READ_QUANTIZE_SUPPORTED.
 
 We removed the trailing '.' from the warning and error messages.
 
-X.  Changes to Libpng from version 1.4.x to 1.5.x
+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 but can be disabled 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);
 
       allowed  - one of
-                 0: disable
-                 1: enable
+                 0: disable benign error (accept the
+                    invalid data without warning).
+                 1: enable benign error (treat the
+                    invalid data as an error or a
+                    warning).
+
+If the error is ignored, or if png_benign_error() treats it as a warning,
+any invalid pixels are decoded as opaque black by the decoder and written
+as-is by the encoder.
 
 Retrieving the maximum palette index found was added at libpng-1.5.15.
 This statement must appear after png_read_png() or png_read_image() while
@@ -4214,9 +4661,10 @@ members of the main libpng control structures, png_struct and png_info,
 deprecated in earlier versions of libpng, has been completely removed from
 libpng 1.5.
 
-We no longer include zlib.h in png.h.  Applications that need access
-to information in zlib.h will need to add the '#include "zlib.h"'
-directive.  It does not matter whether it is placed prior to or after
+We no longer include zlib.h in png.h.  The include statement has been moved
+to pngstruct.h, where it is not accessible by applications. Applications that
+need access to information in zlib.h will need to add the '#include "zlib.h"'
+directive.  It does not matter whether this is placed prior to or after
 the '"#include png.h"' directive.
 
 The png_sprintf(), png_strcpy(), and png_strncpy() macros are no longer used
@@ -4510,7 +4958,120 @@ pngusr.h a system builder may also define equivalent options in pngusr.dfa
 DFA_XTRA to the file name.  The makefiles in contrib/pngminim illustrate
 how to do this, and a case where pngusr.h is still required.
 
-XI. Detecting libpng
+XII.  Changes to Libpng from version 1.5.x to 1.6.x
+
+A "simplified API" has been added (see documentation in png.h and a simple
+example in contrib/examples/pngtopng.c).  The new publicly visible API
+includes the following:
+
+   macros:
+     PNG_FORMAT_*
+     PNG_IMAGE_*
+   structures:
+     png_control
+     png_image
+   read functions
+     png_image_begin_read_from_file()
+     png_image_begin_read_from_stdio()
+     png_image_begin_read_from_memory()
+     png_image_finish_read()
+     png_image_free()
+   write functions
+     png_image_write_to_file()
+     png_image_write_to_stdio()
+
+Starting with libpng-1.6.0, you can configure libpng to prefix all exported
+symbols, using the PNG_PREFIX macro.
+
+We no longer include string.h in png.h.  The include statement has been moved
+to pngpriv.h, where it is not accessible by applications.  Applications that
+need access to information in string.h must add an '#include <string.h>'
+directive.  It does not matter whether this is placed prior to or after
+the '#include "png.h"' directive.
+
+The following API are now DEPRECATED:
+   png_info_init_3()
+   png_convert_to_rfc1123() which has been replaced
+     with png_convert_to_rfc1123_buffer()
+   png_data_freer()
+   png_malloc_default()
+   png_free_default()
+   png_reset_zstream()
+
+The following have been removed:
+   png_get_io_chunk_name(), which has been replaced
+     with png_get_io_chunk_type().  The new
+     function returns a 32-bit integer instead of
+     a string.
+   The png_sizeof(), png_strlen(), png_memcpy(), png_memcmp(), and
+     png_memset() macros are no longer used in the libpng sources and
+     have been removed.  These had already been made invisible to applications
+     (i.e., defined in the private pngpriv.h header file) since libpng-1.5.0.
+
+The signatures of many exported functions were changed, such that
+   png_structp became png_structrp or png_const_structrp
+   png_infop became png_inforp or png_const_inforp
+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 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.
+
+Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
+an empty language field or an empty translated keyword.  Both of these
+are allowed by the PNG specification, so these warnings are no longer issued.
+
+The library now issues an error if the application attempts to set a
+transform after it calls png_read_update_info() 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.
+
+The library now issues a warning if both background processing and RGB to
+gray are used when gamma correction happens. As with previous versions of
+the library the results are numerically very incorrect in this case.
+
+There are some minor arithmetic changes in some transforms such as
+png_set_background(), that might be detected by certain regression tests.
+
+Unknown chunk handling has been improved internally, without any API change.
+This adds more correct option control of the unknown handling, corrects
+a pre-existing bug where the per-chunk 'keep' setting is ignored, and makes
+it possible to skip IDAT chunks in the sequential reader.
+
+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 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 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
+length, which resulted in PNG files that cannot be read beyond the bad iTXt
+chunk.  This error was fixed in libpng-1.6.3, and a tool (called
+contrib/tools/png-fix-itxt) has been added to the libpng distribution.
+
+XIII.  Detecting libpng
 
 The png_get_io_ptr() function has been present since libpng-0.88, has never
 changed, and is unaffected by conditional compilation macros.  It is the
@@ -4519,7 +5080,7 @@ libpng version since 0.88.  In an autoconf "configure.in" you could use
 
     AC_CHECK_LIB(png, png_get_io_ptr, ...
 
-XII. Source code repository
+XV. Source code repository
 
 Since about February 2009, version 1.2.34, libpng has been under "git" source
 control.  The git repository was built from old libpng-x.y.z.tar.gz files
@@ -4530,7 +5091,7 @@ at
 
 or you can browse it with a web browser by selecting the "code" button at
 
-    https://sourceforge.net/projects/libpng/
+    https://sourceforge.net/projects/libpng
 
 Patches can be sent to glennrp at users.sourceforge.net or to
 png-mng-implement at lists.sourceforge.net or you can upload them to
@@ -4543,7 +5104,7 @@ simple verbal discriptions of bug fixes, reported either to the
 SourceForge bug tracker, to the png-mng-implement at lists.sf.net
 mailing list, or directly to glennrp.
 
-XIII. Coding style
+XV. Coding style
 
 Our coding style is similar to the "Allman" style, with curly
 braces on separate lines:
@@ -4628,6 +5189,17 @@ above the comment that says
 
   /* Maintainer: Put new private prototypes here ^ */
 
+We put a space after the "sizeof" operator and we omit the
+optional parentheses around its argument when the argument
+is an expression, not a type name, and we always enclose the
+sizeof operator, with its argument, in parentheses:
+
+  (sizeof (png_uint_32))
+  (sizeof array)
+
+Prior to libpng-1.6.0 we used a "png_sizeof()" macro, formatted as
+though it were a function.
+
 To avoid polluting the global namespace, the names of all exported
 functions and variables begin with "png_", and all publicly visible C
 preprocessor macros begin with "PNG".  We request that applications that
@@ -4650,33 +5222,36 @@ with "defined".
 We prefer to express integers that are used as bit masks in hex format,
 with an even number of lower-case hex digits (e.g., 0x00, 0xff, 0x0100).
 
+We prefer to use underscores in variable names rather than camelCase, except
+for a few type names that we inherit from zlib.h.
+
 We do not use the TAB character for indentation in the C sources.
 
 Lines do not exceed 80 characters.
 
 Other rules can be inferred by inspecting the libpng source.
 
-XIV. Y2K Compliance in libpng
+XVI. Y2K Compliance in libpng
 
-August 21, 2013
+December 14, 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 1.5.18beta01 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.8rc02 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 that
-will hold years up to 65535.  The other holds the date in text
-format, and will hold years up to 9999.
+Libpng only has two year fields.  One is a 2-byte unsigned integer
+that will hold years up to 65535.  The other, which is deprecated,
+holds the date in text format, and will hold years up to 9999.
 
 The integer is
     "png_uint_16 year" in png_time_struct.
 
 The string is
-    "char time_buffer[29]" in png_struct.  This will no
-longer be used in libpng-1.6.x and will be removed from libpng-1.7.0.
+    "char time_buffer[29]" in png_struct.  This is no longer used
+in libpng-1.6.x and will be removed from libpng-1.7.0.
 
 There are seven time-related functions:
 

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "August 21, 2013"
+.TH LIBPNGPF 3 "December 14, 2013"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.5.18beta01
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.8rc02
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
@@ -8,9 +8,9 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.5.18beta01
 \fBAs of libpng version \fP\fI1.5.1\fP\fB, this section is no longer \fP\fImaintained\fP\fB, now that the private function prototypes are hidden in pngpriv.h and not accessible to applications. Look in pngpriv.h for the prototypes and a short description of each \fIfunction.
 
 .SH DESCRIPTION
-The functions previously listed here are used privately by libpng
-and are not recommended for use by applications.  They are
-not "exported" to applications using shared libraries.
+The functions previously listed here are used privately by libpng and are not
+available for use by applications.  They are not "exported" to applications
+using shared libraries.
 
 .SH SEE ALSO
 .BR "png"(5), " libpng"(3), " zlib"(3), " deflate"(5), " " and " zlib"(5)

missing

@@ -1,215 +0,0 @@
-#! /bin/sh
-# Common wrapper for a few potentially missing GNU programs.
-
-scriptversion=2012-06-26.16; # UTC
-
-# Copyright (C) 1996-2012 Free Software Foundation, Inc.
-# Originally written by Fran,cois Pinard <pinard@iro.umontreal.ca>, 1996.
-
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2, or (at your option)
-# any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-# As a special exception to the GNU General Public License, if you
-# distribute this file as part of a program that contains a
-# configuration script generated by Autoconf, you may include it under
-# the same distribution terms that you use for the rest of that program.
-
-if test $# -eq 0; then
-  echo 1>&2 "Try '$0 --help' for more information"
-  exit 1
-fi
-
-case $1 in
-
-  --is-lightweight)
-    # Used by our autoconf macros to check whether the available missing
-    # script is modern enough.
-    exit 0
-    ;;
-
-  --run)
-    # Back-compat with the calling convention used by older automake.
-    shift
-    ;;
-
-  -h|--h|--he|--hel|--help)
-    echo "\
-$0 [OPTION]... PROGRAM [ARGUMENT]...
-
-Run 'PROGRAM [ARGUMENT]...', returning a proper advice when this fails due
-to PROGRAM being missing or too old.
-
-Options:
-  -h, --help      display this help and exit
-  -v, --version   output version information and exit
-
-Supported PROGRAM values:
-  aclocal   autoconf  autoheader   autom4te  automake  makeinfo
-  bison     yacc      flex         lex       help2man
-
-Version suffixes to PROGRAM as well as the prefixes 'gnu-', 'gnu', and
-'g' are ignored when checking the name.
-
-Send bug reports to <bug-automake@gnu.org>."
-    exit $?
-    ;;
-
-  -v|--v|--ve|--ver|--vers|--versi|--versio|--version)
-    echo "missing $scriptversion (GNU Automake)"
-    exit $?
-    ;;
-
-  -*)
-    echo 1>&2 "$0: unknown '$1' option"
-    echo 1>&2 "Try '$0 --help' for more information"
-    exit 1
-    ;;
-
-esac
-
-# Run the given program, remember its exit status.
-"$@"; st=$?
-
-# If it succeeded, we are done.
-test $st -eq 0 && exit 0
-
-# Also exit now if we it failed (or wasn't found), and '--version' was
-# passed; such an option is passed most likely to detect whether the
-# program is present and works.
-case $2 in --version|--help) exit $st;; esac
-
-# Exit code 63 means version mismatch.  This often happens when the user
-# tries to use an ancient version of a tool on a file that requires a
-# minimum version.
-if test $st -eq 63; then
-  msg="probably too old"
-elif test $st -eq 127; then
-  # Program was missing.
-  msg="missing on your system"
-else
-  # Program was found and executed, but failed.  Give up.
-  exit $st
-fi
-
-perl_URL=http://www.perl.org/
-flex_URL=http://flex.sourceforge.net/
-gnu_software_URL=http://www.gnu.org/software
-
-program_details ()
-{
-  case $1 in
-    aclocal|automake)
-      echo "The '$1' program is part of the GNU Automake package:"
-      echo "<$gnu_software_URL/automake>"
-      echo "It also requires GNU Autoconf, GNU m4 and Perl in order to run:"
-      echo "<$gnu_software_URL/autoconf>"
-      echo "<$gnu_software_URL/m4/>"
-      echo "<$perl_URL>"
-      ;;
-    autoconf|autom4te|autoheader)
-      echo "The '$1' program is part of the GNU Autoconf package:"
-      echo "<$gnu_software_URL/autoconf/>"
-      echo "It also requires GNU m4 and Perl in order to run:"
-      echo "<$gnu_software_URL/m4/>"
-      echo "<$perl_URL>"
-      ;;
-  esac
-}
-
-give_advice ()
-{
-  # Normalize program name to check for.
-  normalized_program=`echo "$1" | sed '
-    s/^gnu-//; t
-    s/^gnu//; t
-    s/^g//; t'`
-
-  printf '%s\n' "'$1' is $msg."
-
-  configure_deps="'configure.ac' or m4 files included by 'configure.ac'"
-  case $normalized_program in
-    autoconf*)
-      echo "You should only need it if you modified 'configure.ac',"
-      echo "or m4 files included by it."
-      program_details 'autoconf'
-      ;;
-    autoheader*)
-      echo "You should only need it if you modified 'acconfig.h' or"
-      echo "$configure_deps."
-      program_details 'autoheader'
-      ;;
-    automake*)
-      echo "You should only need it if you modified 'Makefile.am' or"
-      echo "$configure_deps."
-      program_details 'automake'
-      ;;
-    aclocal*)
-      echo "You should only need it if you modified 'acinclude.m4' or"
-      echo "$configure_deps."
-      program_details 'aclocal'
-      ;;
-   autom4te*)
-      echo "You might have modified some maintainer files that require"
-      echo "the 'automa4te' program to be rebuilt."
-      program_details 'autom4te'
-      ;;
-    bison*|yacc*)
-      echo "You should only need it if you modified a '.y' file."
-      echo "You may want to install the GNU Bison package:"
-      echo "<$gnu_software_URL/bison/>"
-      ;;
-    lex*|flex*)
-      echo "You should only need it if you modified a '.l' file."
-      echo "You may want to install the Fast Lexical Analyzer package:"
-      echo "<$flex_URL>"
-      ;;
-    help2man*)
-      echo "You should only need it if you modified a dependency" \
-           "of a man page."
-      echo "You may want to install the GNU Help2man package:"
-      echo "<$gnu_software_URL/help2man/>"
-    ;;
-    makeinfo*)
-      echo "You should only need it if you modified a '.texi' file, or"
-      echo "any other file indirectly affecting the aspect of the manual."
-      echo "You might want to install the Texinfo package:"
-      echo "<$gnu_software_URL/texinfo/>"
-      echo "The spurious makeinfo call might also be the consequence of"
-      echo "using a buggy 'make' (AIX, DU, IRIX), in which case you might"
-      echo "want to install GNU make:"
-      echo "<$gnu_software_URL/make/>"
-      ;;
-    *)
-      echo "You might have modified some files without having the proper"
-      echo "tools for further handling them.  Check the 'README' file, it"
-      echo "often tells you about the needed prerequisites for installing"
-      echo "this package.  You may also peek at any GNU archive site, in"
-      echo "case some other package contains this missing '$1' program."
-      ;;
-  esac
-}
-
-give_advice "$1" | sed -e '1s/^/WARNING: /' \
-                       -e '2,$s/^/         /' >&2
-
-# Propagate the correct exit status (expected to be 127 for a program
-# not found, 63 for a program that failed due to version mismatch).
-exit $st
-
-# Local variables:
-# eval: (add-hook 'write-file-hooks 'time-stamp)
-# time-stamp-start: "scriptversion="
-# time-stamp-format: "%:y-%02m-%02d.%02H"
-# time-stamp-time-zone: "UTC"
-# time-stamp-end: "; # UTC"
-# End:

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "August 21, 2013"
+.TH PNG 5 "December 14, 2013"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION

pngconf.h

@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.5.18beta01 - August 21, 2013
+ * libpng version 1.6.8rc02 - December 14, 2013
  *
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -22,33 +22,69 @@
 #ifndef PNGCONF_H
 #define PNGCONF_H
 
-#ifndef PNG_BUILDING_SYMBOL_TABLE
-/* PNG_NO_LIMITS_H may be used to turn off the use of the standard C
- * definition file for  machine specific limits, this may impact the
- * correctness of the definitions below (see uses of INT_MAX).
- */
-#  ifndef PNG_NO_LIMITS_H
-#    include <limits.h>
+/* To do: Do all of this in scripts/pnglibconf.dfa */
+#ifdef PNG_SAFE_LIMITS_SUPPORTED
+#  ifdef PNG_USER_WIDTH_MAX
+#    undef PNG_USER_WIDTH_MAX
+#    define PNG_USER_WIDTH_MAX 1000000L
 #  endif
-
-/* For the memory copy APIs (i.e. the standard definitions of these),
- * because this file defines png_memcpy and so on the base APIs must
- * be defined here.
- */
-#  ifdef BSD
-#    include <strings.h>
-#  else
-#    include <string.h>
+#  ifdef PNG_USER_HEIGHT_MAX
+#    undef PNG_USER_HEIGHT_MAX
+#    define PNG_USER_HEIGHT_MAX 1000000L
 #  endif
-
-/* For png_FILE_p - this provides the standard definition of a
- * FILE
- */
-#  ifdef PNG_STDIO_SUPPORTED
-#    include <stdio.h>
+#  ifdef PNG_USER_CHUNK_MALLOC_MAX
+#    undef PNG_USER_CHUNK_MALLOC_MAX
+#    define PNG_USER_CHUNK_MALLOC_MAX 4000000L
+#  endif
+#  ifdef PNG_USER_CHUNK_CACHE_MAX
+#    undef PNG_USER_CHUNK_CACHE_MAX
+#    define PNG_USER_CHUNK_CACHE_MAX 128
 #  endif
 #endif
 
+#ifndef PNG_BUILDING_SYMBOL_TABLE /* else includes may cause problems */
+
+/* From libpng 1.6.0 libpng requires an ANSI X3.159-1989 ("ISOC90") compliant C
+ * compiler for correct compilation.  The following header files are required by
+ * the standard.  If your compiler doesn't provide these header files, or they
+ * do not match the standard, you will need to provide/improve them.
+ */
+#include <limits.h>
+#include <stddef.h>
+
+/* Library header files.  These header files are all defined by ISOC90; libpng
+ * expects conformant implementations, however, an ISOC90 conformant system need
+ * not provide these header files if the functionality cannot be implemented.
+ * In this case it will be necessary to disable the relevant parts of libpng in
+ * the build of pnglibconf.h.
+ *
+ * Prior to 1.6.0 string.h was included here; the API changes in 1.6.0 to not
+ * include this unnecessary header file.
+ */
+
+#ifdef PNG_STDIO_SUPPORTED
+   /* Required for the definition of FILE: */
+#  include <stdio.h>
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+   /* Required for the definition of jmp_buf and the declaration of longjmp: */
+#  include <setjmp.h>
+#endif
+
+#ifdef PNG_CONVERT_tIME_SUPPORTED
+   /* Required for struct tm: */
+#  include <time.h>
+#endif
+
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
+
+/* Prior to 1.6.0 it was possible to turn off 'const' in declarations using
+ * PNG_NO_CONST; this is no longer supported except for data declarations which
+ * apparently still cause problems in 2011 on some compilers.
+ */
+#define PNG_CONST const /* backward compatibility only */
+
 /* This controls optimization of the reading of 16 and 32 bit values
  * from PNG files.  It can be set on a per-app-file basis - it
  * just changes whether a macro is used when the function is called.
@@ -72,28 +108,13 @@
  * may be changed on a per-file basis when compiling against libpng.
  */
 
-/* The PNGARG macro protects us against machines that don't have function
- * prototypes (ie K&R style headers).  If your compiler does not handle
- * function prototypes, define this macro and use the included ansi2knr.
- * I've always been able to use _NO_PROTO as the indicator, but you may
- * need to drag the empty declaration out in front of here, or change the
- * ifdef to suit your own needs.
+/* The PNGARG macro was used in versions of libpng prior to 1.6.0 to protect
+ * against legacy (pre ISOC90) compilers that did not understand function
+ * prototypes.  It is not required for modern C compilers.
  */
 #ifndef PNGARG
-
-#  ifdef OF /* zlib prototype munger */
-#    define PNGARG(arglist) OF(arglist)
-#  else
-
-#    ifdef _NO_PROTO
-#      define PNGARG(arglist) ()
-#    else
-#      define PNGARG(arglist) arglist
-#    endif /* _NO_PROTO */
-
-#  endif /* OF */
-
-#endif /* PNGARG */
+#  define PNGARG(arglist) arglist
+#endif
 
 /* Function calling conventions.
  * =============================
@@ -217,10 +238,11 @@
 #      define PNGAPI _stdcall
 #    endif
 #  endif /* compiler/api */
+
   /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
 
 #  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
-   ERROR: PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed
+#     error "PNG_USER_PRIVATEBUILD must be defined if PNGAPI is changed"
 #  endif
 
 #  if (defined(_MSC_VER) && _MSC_VER < 800) ||\
@@ -334,9 +356,10 @@
 
 #ifdef PNG_PEDANTIC_WARNINGS_SUPPORTED
   /* Support for compiler specific function attributes.  These are used
-   * so that where compiler support is available incorrect use of API
+   * so that where compiler support is available, incorrect use of API
    * functions in png.h will generate compiler warnings.  Added at libpng
-   * version 1.2.41.
+   * version 1.2.41.  Disabling these removes the warnings but may also produce
+   * less efficient code.
    */
 #  if defined(__GNUC__)
 #    ifndef PNG_USE_RESULT
@@ -361,15 +384,19 @@
             __attribute__((__deprecated__))
 #        endif
 #      endif
+#      if ((__GNUC__ != 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
+#        ifndef PNG_RESTRICT
+#          define PNG_RESTRICT __restrict
+#        endif
+#      endif /*  __GNUC__ == 3.0 */
 #    endif /*  __GNUC__ >= 3 */
-#  endif /* __GNUC__ */
 
-#  if defined(_MSC_VER)  && (_MSC_VER >= 1300)
+#  elif defined(_MSC_VER)  && (_MSC_VER >= 1300)
 #    ifndef PNG_USE_RESULT
 #      define PNG_USE_RESULT /* not supported */
 #    endif
 #    ifndef PNG_NORETURN
-#      define PNG_NORETURN __declspec(noreturn)
+#      define PNG_NORETURN   __declspec(noreturn)
 #    endif
 #    ifndef PNG_ALLOCATED
 #      if (_MSC_VER >= 1400)
@@ -382,6 +409,16 @@
 #    ifndef PNG_PRIVATE
 #      define PNG_PRIVATE __declspec(deprecated)
 #    endif
+#    ifndef PNG_RESTRICT
+#      if (_MSC_VER >= 1400)
+#        define PNG_RESTRICT __restrict
+#      endif
+#    endif
+
+#  elif defined(__WATCOMC__)
+#    ifndef PNG_RESTRICT
+#      define PNG_RESTRICT __restrict
+#    endif
 #  endif /* _MSC_VER */
 #endif /* PNG_PEDANTIC_WARNINGS */
 
@@ -400,6 +437,9 @@
 #ifndef PNG_PRIVATE
 #  define PNG_PRIVATE     /* This is a private libpng function */
 #endif
+#ifndef PNG_RESTRICT
+#  define PNG_RESTRICT    /* The C99 "restrict" feature */
+#endif
 #ifndef PNG_FP_EXPORT     /* A floating point API. */
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 #     define PNG_FP_EXPORT(ordinal, type, name, args)\
@@ -417,183 +457,161 @@
 #  endif
 #endif
 
-/* The following uses const char * instead of char * for error
- * and warning message functions, so some compilers won't complain.
- * If you do not want to use const, define PNG_NO_CONST here.
+#ifndef PNG_BUILDING_SYMBOL_TABLE
+/* Some typedefs to get us started.  These should be safe on most of the common
+ * platforms.
  *
- * This should not change how the APIs are called, so it can be done
- * on a per-file basis in the application.
+ * png_uint_32 and png_int_32 may, currently, be larger than required to hold a
+ * 32-bit value however this is not normally advisable.
+ *
+ * png_uint_16 and png_int_16 should always be two bytes in size - this is
+ * verified at library build time.
+ *
+ * png_byte must always be one byte in size.
+ *
+ * The checks below use constants from limits.h, as defined by the ISOC90
+ * standard.
  */
-#ifndef PNG_CONST
-#  ifndef PNG_NO_CONST
-#    define PNG_CONST const
-#  else
-#    define PNG_CONST
-#  endif
+#if CHAR_BIT == 8 && UCHAR_MAX == 255
+   typedef unsigned char png_byte;
+#else
+#  error "libpng requires 8 bit bytes"
 #endif
 
-/* Some typedefs to get us started.  These should be safe on most of the
- * common platforms.  The typedefs should be at least as large as the
- * numbers suggest (a png_uint_32 must be at least 32 bits long), but they
- * don't have to be exactly that size.  Some compilers dislike passing
- * unsigned shorts as function parameters, so you may be better off using
- * unsigned int for png_uint_16.
- */
-
-#if defined(INT_MAX) && (INT_MAX > 0x7ffffffeL)
-typedef unsigned int png_uint_32;
-typedef int png_int_32;
+#if INT_MIN == -32768 && INT_MAX == 32767
+   typedef int png_int_16;
+#elif SHRT_MIN == -32768 && SHRT_MAX == 32767
+   typedef short png_int_16;
 #else
-typedef unsigned long png_uint_32;
-typedef long png_int_32;
+#  error "libpng requires a signed 16 bit type"
 #endif
-typedef unsigned short png_uint_16;
-typedef short png_int_16;
-typedef unsigned char png_byte;
 
-#ifdef PNG_NO_SIZE_T
-typedef unsigned int png_size_t;
+#if UINT_MAX == 65535
+   typedef unsigned int png_uint_16;
+#elif USHRT_MAX == 65535
+   typedef unsigned short png_uint_16;
 #else
+#  error "libpng requires an unsigned 16 bit type"
+#endif
+
+#if INT_MIN < -2147483646 && INT_MAX > 2147483646
+   typedef int png_int_32;
+#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
+   typedef long int png_int_32;
+#else
+#  error "libpng requires a signed 32 bit (or more) type"
+#endif
+
+#if UINT_MAX > 4294967294
+   typedef unsigned int png_uint_32;
+#elif ULONG_MAX > 4294967294
+   typedef unsigned long int png_uint_32;
+#else
+#  error "libpng requires an unsigned 32 bit (or more) type"
+#endif
+
+/* Prior to 1.6.0 it was possible to disable the use of size_t, 1.6.0, however,
+ * requires an ISOC90 compiler and relies on consistent behavior of sizeof.
+ */
 typedef size_t png_size_t;
-#endif
-#define png_sizeof(x) (sizeof (x))
+typedef ptrdiff_t png_ptrdiff_t;
 
-/* The following is needed for medium model support.  It cannot be in the
- * pngpriv.h header.  Needs modification for other compilers besides
- * MSC.  Model independent support declares all arrays and pointers to be
- * large using the far keyword.  The zlib version used must also support
- * model independent data.  As of version zlib 1.0.4, the necessary changes
- * have been made in zlib.  The USE_FAR_KEYWORD define triggers other
- * changes that are needed. (Tim Wegner)
+/* libpng needs to know the maximum value of 'size_t' and this controls the
+ * definition of png_alloc_size_t, below.  This maximum value of size_t limits
+ * but does not control the maximum allocations the library makes - there is
+ * direct application control of this through png_set_user_limits().
  */
-
-/* Separate compiler dependencies (problem here is that zlib.h always
- * defines FAR. (SJT)
- */
-#ifdef __BORLANDC__
-#  if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__)
-#    define LDATA 1
-#  else
-#    define LDATA 0
-#  endif
-  /* GRR:  why is Cygwin in here?  Cygwin is not Borland C... */
-#  if !defined(__WIN32__) && !defined(__FLAT__) && !defined(__CYGWIN__)
-#    define PNG_MAX_MALLOC_64K /* only used in build */
-#    if (LDATA != 1)
-#      ifndef FAR
-#        define FAR __far
-#      endif
-#      define USE_FAR_KEYWORD
-#    endif   /* LDATA != 1 */
-         /* Possibly useful for moving data out of default segment.
-          * Uncomment it if you want. Could also define FARDATA as
-          * const if your compiler supports it. (SJT)
-#        define FARDATA FAR
-          */
-#  endif  /* __WIN32__, __FLAT__, __CYGWIN__ */
-#endif   /* __BORLANDC__ */
-
-
-/* Suggest testing for specific compiler first before testing for
- * FAR.  The Watcom compiler defines both __MEDIUM__ and M_I86MM,
- * making reliance oncertain keywords suspect. (SJT)
- */
-
-/* MSC Medium model */
-#ifdef FAR
-#  ifdef M_I86MM
-#    define USE_FAR_KEYWORD
-#    define FARDATA FAR
-#    include <dos.h>
+#ifndef PNG_SMALL_SIZE_T
+   /* Compiler specific tests for systems where size_t is known to be less than
+    * 32 bits (some of these systems may no longer work because of the lack of
+    * 'far' support; see above.)
+    */
+#  if (defined(__TURBOC__) && !defined(__FLAT__)) ||\
+   (defined(_MSC_VER) && defined(MAXSEG_64K))
+#     define PNG_SMALL_SIZE_T
 #  endif
 #endif
 
-/* SJT: default case */
-#ifndef FAR
-#  define FAR
+/* png_alloc_size_t is guaranteed to be no smaller than png_size_t, and no
+ * smaller than png_uint_32.  Casts from png_size_t or png_uint_32 to
+ * png_alloc_size_t are not necessary; in fact, it is recommended not to use
+ * them at all so that the compiler can complain when something turns out to be
+ * problematic.
+ *
+ * Casts in the other direction (from png_alloc_size_t to png_size_t or
+ * png_uint_32) should be explicitly applied; however, we do not expect to
+ * encounter practical situations that require such conversions.
+ *
+ * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than
+ * 4294967295 - i.e. less than the maximum value of png_uint_32.
+ */
+#ifdef PNG_SMALL_SIZE_T
+   typedef png_uint_32 png_alloc_size_t;
+#else
+   typedef png_size_t png_alloc_size_t;
 #endif
 
-/* At this point FAR is always defined */
-#ifndef FARDATA
-#  define FARDATA
-#endif
+/* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
+ * implementations of Intel CPU specific support of user-mode segmented address
+ * spaces, where 16-bit pointers address more than 65536 bytes of memory using
+ * separate 'segment' registers.  The implementation requires two different
+ * types of pointer (only one of which includes the segment value.)
+ *
+ * If required this support is available in version 1.2 of libpng and may be
+ * available in versions through 1.5, although the correctness of the code has
+ * not been verified recently.
+ */
 
-/* Typedef for floating-point numbers that are converted
- * to fixed-point with a multiple of 100,000, e.g., gamma
+/* Typedef for floating-point numbers that are converted to fixed-point with a
+ * multiple of 100,000, e.g., gamma
  */
 typedef png_int_32 png_fixed_point;
 
 /* Add typedefs for pointers */
-typedef void                      FAR * png_voidp;
-typedef PNG_CONST void            FAR * png_const_voidp;
-typedef png_byte                  FAR * png_bytep;
-typedef PNG_CONST png_byte        FAR * png_const_bytep;
-typedef png_uint_32               FAR * png_uint_32p;
-typedef PNG_CONST png_uint_32     FAR * png_const_uint_32p;
-typedef png_int_32                FAR * png_int_32p;
-typedef PNG_CONST png_int_32      FAR * png_const_int_32p;
-typedef png_uint_16               FAR * png_uint_16p;
-typedef PNG_CONST png_uint_16     FAR * png_const_uint_16p;
-typedef png_int_16                FAR * png_int_16p;
-typedef PNG_CONST png_int_16      FAR * png_const_int_16p;
-typedef char                      FAR * png_charp;
-typedef PNG_CONST char            FAR * png_const_charp;
-typedef png_fixed_point           FAR * png_fixed_point_p;
-typedef PNG_CONST png_fixed_point FAR * png_const_fixed_point_p;
-typedef png_size_t                FAR * png_size_tp;
-typedef PNG_CONST png_size_t      FAR * png_const_size_tp;
+typedef void                  * png_voidp;
+typedef const void            * png_const_voidp;
+typedef png_byte              * png_bytep;
+typedef const png_byte        * png_const_bytep;
+typedef png_uint_32           * png_uint_32p;
+typedef const png_uint_32     * png_const_uint_32p;
+typedef png_int_32            * png_int_32p;
+typedef const png_int_32      * png_const_int_32p;
+typedef png_uint_16           * png_uint_16p;
+typedef const png_uint_16     * png_const_uint_16p;
+typedef png_int_16            * png_int_16p;
+typedef const png_int_16      * png_const_int_16p;
+typedef char                  * png_charp;
+typedef const char            * png_const_charp;
+typedef png_fixed_point       * png_fixed_point_p;
+typedef const png_fixed_point * png_const_fixed_point_p;
+typedef png_size_t            * png_size_tp;
+typedef const png_size_t      * png_const_size_tp;
 
 #ifdef PNG_STDIO_SUPPORTED
 typedef FILE            * png_FILE_p;
 #endif
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
-typedef double           FAR * png_doublep;
-typedef PNG_CONST double FAR * png_const_doublep;
+typedef double       * png_doublep;
+typedef const double * png_const_doublep;
 #endif
 
 /* Pointers to pointers; i.e. arrays */
-typedef png_byte        FAR * FAR * png_bytepp;
-typedef png_uint_32     FAR * FAR * png_uint_32pp;
-typedef png_int_32      FAR * FAR * png_int_32pp;
-typedef png_uint_16     FAR * FAR * png_uint_16pp;
-typedef png_int_16      FAR * FAR * png_int_16pp;
-typedef PNG_CONST char  FAR * FAR * png_const_charpp;
-typedef char            FAR * FAR * png_charpp;
-typedef png_fixed_point FAR * FAR * png_fixed_point_pp;
+typedef png_byte        * * png_bytepp;
+typedef png_uint_32     * * png_uint_32pp;
+typedef png_int_32      * * png_int_32pp;
+typedef png_uint_16     * * png_uint_16pp;
+typedef png_int_16      * * png_int_16pp;
+typedef const char      * * png_const_charpp;
+typedef char            * * png_charpp;
+typedef png_fixed_point * * png_fixed_point_pp;
 #ifdef PNG_FLOATING_POINT_SUPPORTED
-typedef double          FAR * FAR * png_doublepp;
+typedef double          * * png_doublepp;
 #endif
 
 /* Pointers to pointers to pointers; i.e., pointer to array */
-typedef char            FAR * FAR * FAR * png_charppp;
+typedef char            * * * png_charppp;
 
-/* png_alloc_size_t is guaranteed to be no smaller than png_size_t,
- * and no smaller than png_uint_32.  Casts from png_size_t or png_uint_32
- * to png_alloc_size_t are not necessary; in fact, it is recommended
- * not to use them at all so that the compiler can complain when something
- * turns out to be problematic.
- * Casts in the other direction (from png_alloc_size_t to png_size_t or
- * png_uint_32) should be explicitly applied; however, we do not expect
- * to encounter practical situations that require such conversions.
- */
-#if defined(__TURBOC__) && !defined(__FLAT__)
-   typedef unsigned long png_alloc_size_t;
-#else
-#  if defined(_MSC_VER) && defined(MAXSEG_64K)
-     typedef unsigned long    png_alloc_size_t;
-#  else
-     /* This is an attempt to detect an old Windows system where (int) is
-      * actually 16 bits, in that case png_malloc must have an argument with a
-      * bigger size to accomodate the requirements of the library.
-      */
-#    if (defined(_Windows) || defined(_WINDOWS) || defined(_WINDOWS_)) && \
-        (!defined(INT_MAX) || INT_MAX <= 0x7ffffffeL)
-       typedef DWORD         png_alloc_size_t;
-#    else
-       typedef png_size_t    png_alloc_size_t;
-#    endif
-#  endif
-#endif
+#endif /* PNG_BUILDING_SYMBOL_TABLE */
 
 #endif /* PNGCONF_H */

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 1.5.18 [(PENDING RELEASE)]
  *
  * 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 1.5.14 [January 24, 2013]
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
  * 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.)
@@ -20,12 +20,12 @@
 
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
-static PNG_FUNCTION(void, png_default_error,PNGARG((png_structp png_ptr,
+static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
     png_const_charp error_message)),PNG_NORETURN);
 
 #ifdef PNG_WARNINGS_SUPPORTED
 static void /* PRIVATE */
-png_default_warning PNGARG((png_structp png_ptr,
+png_default_warning PNGARG((png_const_structrp png_ptr,
    png_const_charp warning_message));
 #endif /* PNG_WARNINGS_SUPPORTED */
 
@@ -36,7 +36,8 @@ png_default_warning PNGARG((png_structp png_ptr,
  */
 #ifdef PNG_ERROR_TEXT_SUPPORTED
 PNG_FUNCTION(void,PNGAPI
-png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN)
+png_error,(png_const_structrp png_ptr, png_const_charp error_message),
+   PNG_NORETURN)
 {
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
    char msg[16];
@@ -79,7 +80,8 @@ png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN)
    }
 #endif
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_ptr, error_message);
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
+          error_message);
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
@@ -87,7 +89,7 @@ png_error,(png_structp png_ptr, png_const_charp error_message),PNG_NORETURN)
 }
 #else
 PNG_FUNCTION(void,PNGAPI
-png_err,(png_structp png_ptr),PNG_NORETURN)
+png_err,(png_const_structrp png_ptr),PNG_NORETURN)
 {
    /* Prior to 1.5.2 the error_fn received a NULL pointer, expressed
     * erroneously as '\0', instead of the empty string "".  This was
@@ -95,7 +97,7 @@ png_err,(png_structp png_ptr),PNG_NORETURN)
     * will crash in this case.
     */
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_ptr, "");
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), "");
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
@@ -211,7 +213,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
  * png_set_error_fn() to replace the warning function at run-time.
  */
 void PNGAPI
-png_warning(png_structp png_ptr, png_const_charp warning_message)
+png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 {
    int offset = 0;
    if (png_ptr != NULL)
@@ -230,7 +232,8 @@ png_warning(png_structp png_ptr, png_const_charp warning_message)
       }
    }
    if (png_ptr != NULL && png_ptr->warning_fn != NULL)
-      (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
+      (*(png_ptr->warning_fn))(png_constcast(png_structrp,png_ptr),
+         warning_message + offset);
    else
       png_default_warning(png_ptr, warning_message + offset);
 }
@@ -278,7 +281,7 @@ png_warning_parameter_signed(png_warning_parameters p, int number, int format,
 }
 
 void
-png_formatted_warning(png_structp png_ptr, png_warning_parameters p,
+png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
    png_const_charp message)
 {
    /* The internal buffer is just 192 bytes - enough for all our messages,
@@ -346,9 +349,9 @@ png_formatted_warning(png_structp png_ptr, png_warning_parameters p,
    /* i is always less than (sizeof msg), so: */
    msg[i] = '\0';
 
-   /* And this is the formatted message, it may be larger than
-    * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these are
-    * not (currently) formatted.
+   /* And this is the formatted message. It may be larger than
+    * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
+    * are not (currently) formatted.
     */
    png_warning(png_ptr, msg);
 }
@@ -356,14 +359,61 @@ png_formatted_warning(png_structp png_ptr, png_warning_parameters p,
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 void PNGAPI
-png_benign_error(png_structp png_ptr, png_const_charp error_message)
+png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
 {
-  if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+   {
+#     ifdef PNG_READ_SUPPORTED
+         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+            png_ptr->chunk_name != 0)
+            png_chunk_warning(png_ptr, error_message);
+         else
+#     endif
+      png_warning(png_ptr, error_message);
+   }
+
+   else
+   {
+#     ifdef PNG_READ_SUPPORTED
+         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+            png_ptr->chunk_name != 0)
+            png_chunk_error(png_ptr, error_message);
+         else
+#     endif
+      png_error(png_ptr, error_message);
+   }
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+
+void /* PRIVATE */
+png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
+{
+  if (png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN)
      png_warning(png_ptr, error_message);
   else
      png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
-#endif
+
+void /* PRIVATE */
+png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+  if (png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN)
+     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 */
 
 /* These utilities are used internally to build an error message that relates
  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
@@ -377,10 +427,11 @@ static PNG_CONST char png_digit[16] = {
    'A', 'B', 'C', 'D', 'E', 'F'
 };
 
-#define PNG_MAX_ERROR_TEXT 64
-#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
 static void /* PRIVATE */
-png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
+png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
     error_message)
 {
    png_uint_32 chunk_name = png_ptr->chunk_name;
@@ -426,7 +477,7 @@ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
 
 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
 PNG_FUNCTION(void,PNGAPI
-png_chunk_error,(png_structp png_ptr, png_const_charp error_message),
+png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
    PNG_NORETURN)
 {
    char msg[18+PNG_MAX_ERROR_TEXT];
@@ -443,7 +494,7 @@ png_chunk_error,(png_structp png_ptr, png_const_charp error_message),
 
 #ifdef PNG_WARNINGS_SUPPORTED
 void PNGAPI
-png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
+png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 {
    char msg[18+PNG_MAX_ERROR_TEXT];
    if (png_ptr == NULL)
@@ -460,27 +511,71 @@ png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
 #ifdef PNG_READ_SUPPORTED
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 void PNGAPI
-png_chunk_benign_error(png_structp png_ptr, png_const_charp error_message)
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+    error_message)
 {
    if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
       png_chunk_warning(png_ptr, error_message);
 
    else
       png_chunk_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 #endif
 #endif /* PNG_READ_SUPPORTED */
 
+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.
+    */
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      if (png_ptr->mode & PNG_IS_READ_STRUCT)
+#  endif
+
+#  ifdef PNG_READ_SUPPORTED
+      {
+         if (error < PNG_CHUNK_ERROR)
+            png_chunk_warning(png_ptr, message);
+
+         else
+            png_chunk_benign_error(png_ptr, message);
+      }
+#  endif
+
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      else if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
+#  endif
+
+#  ifdef PNG_WRITE_SUPPORTED
+      {
+         if (error < PNG_CHUNK_WRITE_ERROR)
+            png_app_warning(png_ptr, message);
+
+         else
+            png_app_error(png_ptr, message);
+      }
+#  endif
+}
+
 #ifdef PNG_ERROR_TEXT_SUPPORTED
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 PNG_FUNCTION(void,
-png_fixed_error,(png_structp png_ptr, png_const_charp name),PNG_NORETURN)
+png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
 {
 #  define fixed_message "fixed point overflow in "
 #  define fixed_message_ln ((sizeof fixed_message)-1)
    int  iin;
    char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
-   png_memcpy(msg, fixed_message, fixed_message_ln);
+   memcpy(msg, fixed_message, fixed_message_ln);
    iin = 0;
    if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
    {
@@ -498,14 +593,111 @@ png_fixed_error,(png_structp png_ptr, png_const_charp name),PNG_NORETURN)
  * otherwise it is necessary for png_default_error to be overridden.
  */
 jmp_buf* PNGAPI
-png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
+png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
     size_t jmp_buf_size)
 {
-   if (png_ptr == NULL || jmp_buf_size != png_sizeof(jmp_buf))
+   /* From libpng 1.6.0 the app gets one chance to set a 'jmpbuf_size' value
+    * and it must not change after that.  Libpng doesn't care how big the
+    * buffer is, just that it doesn't change.
+    *
+    * If the buffer size is no *larger* than the size of jmp_buf when libpng is
+    * compiled a built in jmp_buf is returned; this preserves the pre-1.6.0
+    * semantics that this call will not fail.  If the size is larger, however,
+    * the buffer is allocated and this may fail, causing the function to return
+    * NULL.
+    */
+   if (png_ptr == NULL)
       return NULL;
 
+   if (png_ptr->jmp_buf_ptr == NULL)
+   {
+      png_ptr->jmp_buf_size = 0; /* not allocated */
+
+      if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
+         png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
+
+      else
+      {
+         png_ptr->jmp_buf_ptr = png_voidcast(jmp_buf *,
+            png_malloc_warn(png_ptr, jmp_buf_size));
+
+         if (png_ptr->jmp_buf_ptr == NULL)
+            return NULL; /* new NULL return on OOM */
+
+         png_ptr->jmp_buf_size = jmp_buf_size;
+      }
+   }
+
+   else /* Already allocated: check the size */
+   {
+      size_t size = png_ptr->jmp_buf_size;
+
+      if (size == 0)
+      {
+         size = (sizeof png_ptr->jmp_buf_local);
+         if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
+         {
+            /* This is an internal error in libpng: somehow we have been left
+             * with a stack allocated jmp_buf when the application regained
+             * control.  It's always possible to fix this up, but for the moment
+             * this is a png_error because that makes it easy to detect.
+             */
+            png_error(png_ptr, "Libpng jmp_buf still allocated");
+            /* png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local; */
+         }
+      }
+
+      if (size != jmp_buf_size)
+      {
+         png_warning(png_ptr, "Application jmp_buf size changed");
+         return NULL; /* caller will probably crash: no choice here */
+      }
+   }
+
+   /* Finally fill in the function, now we have a satisfactory buffer. It is
+    * valid to change the function on every call.
+    */
    png_ptr->longjmp_fn = longjmp_fn;
-   return &png_ptr->longjmp_buffer;
+   return png_ptr->jmp_buf_ptr;
+}
+
+void /* PRIVATE */
+png_free_jmpbuf(png_structrp png_ptr)
+{
+   if (png_ptr != NULL)
+   {
+      jmp_buf *jb = png_ptr->jmp_buf_ptr;
+
+      /* A size of 0 is used to indicate a local, stack, allocation of the
+       * pointer; used here and in png.c
+       */
+      if (jb != NULL && png_ptr->jmp_buf_size > 0)
+      {
+
+         /* This stuff is so that a failure to free the error control structure
+          * does not leave libpng in a state with no valid error handling: the
+          * free always succeeds, if there is an error it gets ignored.
+          */
+         if (jb != &png_ptr->jmp_buf_local)
+         {
+            /* Make an internal, libpng, jmp_buf to return here */
+            jmp_buf free_jmp_buf;
+
+            if (!setjmp(free_jmp_buf))
+            {
+               png_ptr->jmp_buf_ptr = &free_jmp_buf; /* come back here */
+               png_ptr->jmp_buf_size = 0; /* stack allocation */
+               png_ptr->longjmp_fn = longjmp;
+               png_free(png_ptr, jb); /* Return to setjmp on error */
+            }
+         }
+      }
+
+      /* *Always* cancel everything out: */
+      png_ptr->jmp_buf_size = 0;
+      png_ptr->jmp_buf_ptr = NULL;
+      png_ptr->longjmp_fn = 0;
+   }
 }
 #endif
 
@@ -515,7 +707,7 @@ png_set_longjmp_fn(png_structp png_ptr, png_longjmp_ptr longjmp_fn,
  * error function pointer in png_set_error_fn().
  */
 static PNG_FUNCTION(void /* PRIVATE */,
-png_default_error,(png_structp png_ptr, png_const_charp error_message),
+png_default_error,(png_const_structrp png_ptr, png_const_charp error_message),
    PNG_NORETURN)
 {
 #ifdef PNG_CONSOLE_IO_SUPPORTED
@@ -562,23 +754,13 @@ png_default_error,(png_structp png_ptr, png_const_charp error_message),
 }
 
 PNG_FUNCTION(void,PNGAPI
-png_longjmp,(png_structp png_ptr, int val),PNG_NORETURN)
+png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
 {
 #ifdef PNG_SETJMP_SUPPORTED
-   if (png_ptr && png_ptr->longjmp_fn)
-   {
-#  ifdef USE_FAR_KEYWORD
-      {
-         jmp_buf tmp_jmpbuf;
-         png_memcpy(tmp_jmpbuf, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
-         png_ptr->longjmp_fn(tmp_jmpbuf, val);
-      }
-
-#  else
-   png_ptr->longjmp_fn(png_ptr->longjmp_buffer, val);
-#  endif
-   }
+   if (png_ptr && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
+      png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
 #endif
+
    /* Here if not setjmp support or if png_ptr is null. */
    PNG_ABORT();
 }
@@ -590,7 +772,7 @@ png_longjmp,(png_structp png_ptr, int val),PNG_NORETURN)
  * not used, but it is passed in case it may be useful.
  */
 static void /* PRIVATE */
-png_default_warning(png_structp png_ptr, png_const_charp warning_message)
+png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 {
 #ifdef PNG_CONSOLE_IO_SUPPORTED
 #  ifdef PNG_ERROR_NUMBERS_SUPPORTED
@@ -637,10 +819,10 @@ png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 /* This function is called when the application wants to use another method
  * of handling errors and warnings.  Note that the error function MUST NOT
  * return to the calling routine or serious problems will occur.  The return
- * method used in the default routine calls longjmp(png_ptr->longjmp_buffer, 1)
+ * method used in the default routine calls longjmp(png_ptr->jmp_buf_ptr, 1)
  */
 void PNGAPI
-png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
+png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr,
     png_error_ptr error_fn, png_error_ptr warning_fn)
 {
    if (png_ptr == NULL)
@@ -661,7 +843,7 @@ png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
  * pointer before png_write_destroy and png_read_destroy are called.
  */
 png_voidp PNGAPI
-png_get_error_ptr(png_const_structp png_ptr)
+png_get_error_ptr(png_const_structrp png_ptr)
 {
    if (png_ptr == NULL)
       return NULL;
@@ -672,7 +854,7 @@ png_get_error_ptr(png_const_structp png_ptr)
 
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
 void PNGAPI
-png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
+png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
 {
    if (png_ptr != NULL)
    {
@@ -682,4 +864,90 @@ png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
    }
 }
 #endif
+
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
+   /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
+    * possible to implement without setjmp support just so long as there is some
+    * way to handle the error return here:
+    */
+PNG_FUNCTION(void /* PRIVATE */,
+png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
+   PNG_NORETURN)
+{
+   const png_const_structrp png_ptr = png_nonconst_ptr;
+   png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+   /* An error is always logged here, overwriting anything (typically a warning)
+    * that is already there:
+    */
+   if (image != NULL)
+   {
+      png_safecat(image->message, (sizeof image->message), 0, error_message);
+      image->warning_or_error |= PNG_IMAGE_ERROR;
+
+      /* Retrieve the jmp_buf from within the png_control, making this work for
+       * C++ compilation too is pretty tricky: C++ wants a pointer to the first
+       * element of a jmp_buf, but C doesn't tell us the type of that.
+       */
+      if (image->opaque != NULL && image->opaque->error_buf != NULL)
+         longjmp(png_control_jmp_buf(image->opaque), 1);
+
+      /* Missing longjmp buffer, the following is to help debugging: */
+      {
+         size_t pos = png_safecat(image->message, (sizeof image->message), 0,
+            "bad longjmp: ");
+         png_safecat(image->message, (sizeof image->message), pos,
+             error_message);
+      }
+   }
+
+   /* Here on an internal programming error. */
+   abort();
+}
+
+#ifdef PNG_WARNINGS_SUPPORTED
+void /* PRIVATE */
+png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
+{
+   const png_const_structrp png_ptr = png_nonconst_ptr;
+   png_imagep image = png_voidcast(png_imagep, png_ptr->error_ptr);
+
+   /* A warning is only logged if there is no prior warning or error. */
+   if (image->warning_or_error == 0)
+   {
+      png_safecat(image->message, (sizeof image->message), 0, warning_message);
+      image->warning_or_error |= PNG_IMAGE_WARNING;
+   }
+}
+#endif
+
+int /* PRIVATE */
+png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
+{
+   volatile png_imagep image = image_in;
+   volatile int result;
+   volatile png_voidp saved_error_buf;
+   jmp_buf safe_jmpbuf;
+
+   /* Safely execute function(arg) with png_error returning to this function. */
+   saved_error_buf = image->opaque->error_buf;
+   result = setjmp(safe_jmpbuf) == 0;
+
+   if (result)
+   {
+
+      image->opaque->error_buf = safe_jmpbuf;
+      result = function(arg);
+   }
+
+   image->opaque->error_buf = saved_error_buf;
+
+   /* And do the cleanup prior to any failure return. */
+   if (!result)
+      png_image_free(image);
+
+   return result;
+}
+#endif /* SIMPLIFIED READ/WRITE */
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

pngget.c

@@ -1,7 +1,7 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.5.15 [March 28, 2013]
+ * Last changed in libpng 1.6.1 [March 28, 2013]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -17,7 +17,7 @@
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
 png_uint_32 PNGAPI
-png_get_valid(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_uint_32 flag)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -27,7 +27,7 @@ png_get_valid(png_const_structp png_ptr, png_const_infop info_ptr,
 }
 
 png_size_t PNGAPI
-png_get_rowbytes(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return(info_ptr->rowbytes);
@@ -37,7 +37,7 @@ png_get_rowbytes(png_const_structp png_ptr, png_const_infop info_ptr)
 
 #ifdef PNG_INFO_IMAGE_SUPPORTED
 png_bytepp PNGAPI
-png_get_rows(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_rows(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return(info_ptr->row_pointers);
@@ -49,7 +49,7 @@ png_get_rows(png_const_structp png_ptr, png_const_infop info_ptr)
 #ifdef PNG_EASY_ACCESS_SUPPORTED
 /* Easy access to info, added in libpng-0.99 */
 png_uint_32 PNGAPI
-png_get_image_width(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_image_width(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return info_ptr->width;
@@ -58,7 +58,7 @@ png_get_image_width(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_uint_32 PNGAPI
-png_get_image_height(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_image_height(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return info_ptr->height;
@@ -67,7 +67,7 @@ png_get_image_height(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_byte PNGAPI
-png_get_bit_depth(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_bit_depth(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return info_ptr->bit_depth;
@@ -76,7 +76,7 @@ png_get_bit_depth(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_byte PNGAPI
-png_get_color_type(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_color_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return info_ptr->color_type;
@@ -85,7 +85,7 @@ png_get_color_type(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_byte PNGAPI
-png_get_filter_type(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_filter_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return info_ptr->filter_type;
@@ -94,7 +94,7 @@ png_get_filter_type(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_byte PNGAPI
-png_get_interlace_type(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_interlace_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return info_ptr->interlace_type;
@@ -103,7 +103,7 @@ png_get_interlace_type(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_byte PNGAPI
-png_get_compression_type(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return info_ptr->compression_type;
@@ -112,7 +112,8 @@ png_get_compression_type(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_uint_32 PNGAPI
-png_get_x_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -129,7 +130,8 @@ png_get_x_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_uint_32 PNGAPI
-png_get_y_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+    info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -146,7 +148,7 @@ png_get_y_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_uint_32 PNGAPI
-png_get_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -164,7 +166,8 @@ png_get_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 float PNGAPI
-png_get_pixel_aspect_ratio(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
 {
 #ifdef PNG_READ_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
@@ -186,8 +189,8 @@ png_get_pixel_aspect_ratio(png_const_structp png_ptr, png_const_infop info_ptr)
 
 #ifdef PNG_FIXED_POINT_SUPPORTED
 png_fixed_point PNGAPI
-png_get_pixel_aspect_ratio_fixed(png_const_structp png_ptr,
-    png_const_infop info_ptr)
+png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
+    png_const_inforp info_ptr)
 {
 #ifdef PNG_READ_pHYs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)
@@ -216,7 +219,7 @@ png_get_pixel_aspect_ratio_fixed(png_const_structp png_ptr,
 #endif
 
 png_int_32 PNGAPI
-png_get_x_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
@@ -232,7 +235,7 @@ png_get_x_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_int_32 PNGAPI
-png_get_y_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
@@ -248,7 +251,7 @@ png_get_y_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_int_32 PNGAPI
-png_get_x_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
@@ -264,7 +267,7 @@ png_get_x_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr)
 }
 
 png_int_32 PNGAPI
-png_get_y_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
@@ -313,26 +316,26 @@ ppi_from_ppm(png_uint_32 ppm)
 }
 
 png_uint_32 PNGAPI
-png_get_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr));
 }
 
 png_uint_32 PNGAPI
-png_get_x_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_x_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));
 }
 
 png_uint_32 PNGAPI
-png_get_y_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_y_pixels_per_inch(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr));
 }
 
 #ifdef PNG_FIXED_POINT_SUPPORTED
 static png_fixed_point
-png_fixed_inches_from_microns(png_structp png_ptr, png_int_32 microns)
+png_fixed_inches_from_microns(png_const_structrp png_ptr, png_int_32 microns)
 {
    /* Convert from metres * 1,000,000 to inches * 100,000, meters to
     * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127.
@@ -343,8 +346,8 @@ png_fixed_inches_from_microns(png_structp png_ptr, png_int_32 microns)
 }
 
 png_fixed_point PNGAPI
-png_get_x_offset_inches_fixed(png_structp png_ptr,
-    png_const_infop info_ptr)
+png_get_x_offset_inches_fixed(png_const_structrp png_ptr,
+    png_const_inforp info_ptr)
 {
    return png_fixed_inches_from_microns(png_ptr,
        png_get_x_offset_microns(png_ptr, info_ptr));
@@ -353,8 +356,8 @@ png_get_x_offset_inches_fixed(png_structp png_ptr,
 
 #ifdef PNG_FIXED_POINT_SUPPORTED
 png_fixed_point PNGAPI
-png_get_y_offset_inches_fixed(png_structp png_ptr,
-    png_const_infop info_ptr)
+png_get_y_offset_inches_fixed(png_const_structrp png_ptr,
+    png_const_inforp info_ptr)
 {
    return png_fixed_inches_from_microns(png_ptr,
        png_get_y_offset_microns(png_ptr, info_ptr));
@@ -363,7 +366,7 @@ png_get_y_offset_inches_fixed(png_structp png_ptr,
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 float PNGAPI
-png_get_x_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_x_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    /* To avoid the overflow do the conversion directly in floating
     * point.
@@ -374,7 +377,7 @@ png_get_x_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr)
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 float PNGAPI
-png_get_y_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_y_offset_inches(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    /* To avoid the overflow do the conversion directly in floating
     * point.
@@ -385,7 +388,7 @@ png_get_y_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr)
 
 #ifdef PNG_pHYs_SUPPORTED
 png_uint_32 PNGAPI
-png_get_pHYs_dpi(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
 {
    png_uint_32 retval = 0;
@@ -428,8 +431,9 @@ png_get_pHYs_dpi(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #endif  /* PNG_EASY_ACCESS_SUPPORTED */
 
+
 png_byte PNGAPI
-png_get_channels(png_const_structp png_ptr, png_const_infop info_ptr)
+png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return(info_ptr->channels);
@@ -437,18 +441,20 @@ png_get_channels(png_const_structp png_ptr, png_const_infop info_ptr)
    return (0);
 }
 
+#ifdef PNG_READ_SUPPORTED
 png_const_bytep PNGAPI
-png_get_signature(png_const_structp png_ptr, png_infop info_ptr)
+png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
       return(info_ptr->signature);
 
    return (NULL);
 }
+#endif
 
 #ifdef PNG_bKGD_SUPPORTED
 png_uint_32 PNGAPI
-png_get_bKGD(png_const_structp png_ptr, png_infop info_ptr,
+png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
    png_color_16p *background)
 {
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
@@ -469,87 +475,47 @@ png_get_bKGD(png_const_structp png_ptr, png_infop info_ptr,
  * same time to correct the rgb grayscale coefficient defaults obtained from the
  * cHRM chunk in 1.5.4
  */
-png_uint_32 PNGFAPI
-png_get_cHRM_XYZ_fixed(png_structp png_ptr, png_const_infop info_ptr,
-    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
-    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
-    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
-    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
-    png_fixed_point *int_blue_Z)
-{
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
-   {
-      png_xy xy;
-      png_XYZ XYZ;
-
-      png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
-
-      xy.whitex = info_ptr->x_white;
-      xy.whitey = info_ptr->y_white;
-      xy.redx = info_ptr->x_red;
-      xy.redy = info_ptr->y_red;
-      xy.greenx = info_ptr->x_green;
-      xy.greeny = info_ptr->y_green;
-      xy.bluex = info_ptr->x_blue;
-      xy.bluey = info_ptr->y_blue;
-
-      /* The *_checked function handles error reporting, so just return 0 if
-       * there is a failure here.
-       */
-      if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
-      {
-         if (int_red_X != NULL)
-            *int_red_X = XYZ.redX;
-         if (int_red_Y != NULL)
-            *int_red_Y = XYZ.redY;
-         if (int_red_Z != NULL)
-            *int_red_Z = XYZ.redZ;
-         if (int_green_X != NULL)
-            *int_green_X = XYZ.greenX;
-         if (int_green_Y != NULL)
-            *int_green_Y = XYZ.greenY;
-         if (int_green_Z != NULL)
-            *int_green_Z = XYZ.greenZ;
-         if (int_blue_X != NULL)
-            *int_blue_X = XYZ.blueX;
-         if (int_blue_Y != NULL)
-            *int_blue_Y = XYZ.blueY;
-         if (int_blue_Z != NULL)
-            *int_blue_Z = XYZ.blueZ;
-
-         return (PNG_INFO_cHRM);
-      }
-   }
-
-   return (0);
-}
-
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32 PNGAPI
-png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
     double *white_x, double *white_y, double *red_x, double *red_y,
     double *green_x, double *green_y, double *blue_x, double *blue_y)
 {
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   /* Quiet API change: this code used to only return the end points if a cHRM
+    * chunk was present, but the end points can also come from iCCP or sRGB
+    * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and
+    * the png_set_ APIs merely check that set end points are mutually
+    * consistent.
+    */
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
    {
       png_debug1(1, "in %s retrieval function", "cHRM");
 
       if (white_x != NULL)
-         *white_x = png_float(png_ptr, info_ptr->x_white, "cHRM white X");
+         *white_x = png_float(png_ptr,
+            info_ptr->colorspace.end_points_xy.whitex, "cHRM white X");
       if (white_y != NULL)
-         *white_y = png_float(png_ptr, info_ptr->y_white, "cHRM white Y");
+         *white_y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y");
       if (red_x != NULL)
-         *red_x = png_float(png_ptr, info_ptr->x_red, "cHRM red X");
+         *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx,
+            "cHRM red X");
       if (red_y != NULL)
-         *red_y = png_float(png_ptr, info_ptr->y_red, "cHRM red Y");
+         *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy,
+            "cHRM red Y");
       if (green_x != NULL)
-         *green_x = png_float(png_ptr, info_ptr->x_green, "cHRM green X");
+         *green_x = png_float(png_ptr,
+            info_ptr->colorspace.end_points_xy.greenx, "cHRM green X");
       if (green_y != NULL)
-         *green_y = png_float(png_ptr, info_ptr->y_green, "cHRM green Y");
+         *green_y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y");
       if (blue_x != NULL)
-         *blue_x = png_float(png_ptr, info_ptr->x_blue, "cHRM blue X");
+         *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex,
+            "cHRM blue X");
       if (blue_y != NULL)
-         *blue_y = png_float(png_ptr, info_ptr->y_blue, "cHRM blue Y");
+         *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey,
+            "cHRM blue Y");
       return (PNG_INFO_cHRM);
    }
 
@@ -557,35 +523,43 @@ png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr,
 }
 
 png_uint_32 PNGAPI
-png_get_cHRM_XYZ(png_structp png_ptr, png_const_infop info_ptr,
+png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
    double *red_X, double *red_Y, double *red_Z, double *green_X,
    double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
    double *blue_Z)
 {
-   png_XYZ XYZ;
-
-   if (png_get_cHRM_XYZ_fixed(png_ptr, info_ptr,
-      &XYZ.redX, &XYZ.redY, &XYZ.redZ, &XYZ.greenX, &XYZ.greenY, &XYZ.greenZ,
-      &XYZ.blueX, &XYZ.blueY, &XYZ.blueZ) & PNG_INFO_cHRM)
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
    {
+      png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
+
       if (red_X != NULL)
-         *red_X = png_float(png_ptr, XYZ.redX, "cHRM red X");
+         *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
+            "cHRM red X");
       if (red_Y != NULL)
-         *red_Y = png_float(png_ptr, XYZ.redY, "cHRM red Y");
+         *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
+            "cHRM red Y");
       if (red_Z != NULL)
-         *red_Z = png_float(png_ptr, XYZ.redZ, "cHRM red Z");
+         *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
+            "cHRM red Z");
       if (green_X != NULL)
-         *green_X = png_float(png_ptr, XYZ.greenX, "cHRM green X");
+         *green_X = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
       if (green_Y != NULL)
-         *green_Y = png_float(png_ptr, XYZ.greenY, "cHRM green Y");
+         *green_Y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
       if (green_Z != NULL)
-         *green_Z = png_float(png_ptr, XYZ.greenZ, "cHRM green Z");
+         *green_Z = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
       if (blue_X != NULL)
-         *blue_X = png_float(png_ptr, XYZ.blueX, "cHRM blue X");
+         *blue_X = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X");
       if (blue_Y != NULL)
-         *blue_Y = png_float(png_ptr, XYZ.blueY, "cHRM blue Y");
+         *blue_Y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y");
       if (blue_Z != NULL)
-         *blue_Z = png_float(png_ptr, XYZ.blueZ, "cHRM blue Z");
+         *blue_Z = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
       return (PNG_INFO_cHRM);
    }
 
@@ -595,31 +569,69 @@ png_get_cHRM_XYZ(png_structp png_ptr, png_const_infop info_ptr,
 
 #  ifdef PNG_FIXED_POINT_SUPPORTED
 png_uint_32 PNGAPI
-png_get_cHRM_fixed(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+    png_fixed_point *int_blue_Z)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
+   {
+      png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
+
+      if (int_red_X != NULL)
+         *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
+      if (int_red_Y != NULL)
+         *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
+      if (int_red_Z != NULL)
+         *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
+      if (int_green_X != NULL)
+         *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
+      if (int_green_Y != NULL)
+         *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
+      if (int_green_Z != NULL)
+         *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
+      if (int_blue_X != NULL)
+         *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
+      if (int_blue_Y != NULL)
+         *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
+      if (int_blue_Z != NULL)
+         *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
+      return (PNG_INFO_cHRM);
+   }
+
+   return (0);
+}
+
+png_uint_32 PNGAPI
+png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
     png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
     png_fixed_point *blue_x, png_fixed_point *blue_y)
 {
    png_debug1(1, "in %s retrieval function", "cHRM");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS))
    {
       if (white_x != NULL)
-         *white_x = info_ptr->x_white;
+         *white_x = info_ptr->colorspace.end_points_xy.whitex;
       if (white_y != NULL)
-         *white_y = info_ptr->y_white;
+         *white_y = info_ptr->colorspace.end_points_xy.whitey;
       if (red_x != NULL)
-         *red_x = info_ptr->x_red;
+         *red_x = info_ptr->colorspace.end_points_xy.redx;
       if (red_y != NULL)
-         *red_y = info_ptr->y_red;
+         *red_y = info_ptr->colorspace.end_points_xy.redy;
       if (green_x != NULL)
-         *green_x = info_ptr->x_green;
+         *green_x = info_ptr->colorspace.end_points_xy.greenx;
       if (green_y != NULL)
-         *green_y = info_ptr->y_green;
+         *green_y = info_ptr->colorspace.end_points_xy.greeny;
       if (blue_x != NULL)
-         *blue_x = info_ptr->x_blue;
+         *blue_x = info_ptr->colorspace.end_points_xy.bluex;
       if (blue_y != NULL)
-         *blue_y = info_ptr->y_blue;
+         *blue_y = info_ptr->colorspace.end_points_xy.bluey;
       return (PNG_INFO_cHRM);
    }
 
@@ -629,41 +641,49 @@ png_get_cHRM_fixed(png_const_structp png_ptr, png_const_infop info_ptr,
 #endif
 
 #ifdef PNG_gAMA_SUPPORTED
-png_uint_32 PNGFAPI
-png_get_gAMA_fixed(png_const_structp png_ptr, png_const_infop info_ptr,
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_fixed_point *file_gamma)
 {
    png_debug1(1, "in %s retrieval function", "gAMA");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
-       && file_gamma != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) &&
+      file_gamma != NULL)
    {
-      *file_gamma = info_ptr->gamma;
+      *file_gamma = info_ptr->colorspace.gamma;
       return (PNG_INFO_gAMA);
    }
 
    return (0);
 }
+#  endif
+
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32 PNGAPI
-png_get_gAMA(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
     double *file_gamma)
 {
-   png_fixed_point igamma;
-   png_uint_32 ok = png_get_gAMA_fixed(png_ptr, info_ptr, &igamma);
+   png_debug1(1, "in %s retrieval function", "gAMA(float)");
 
-   if (ok)
-      *file_gamma = png_float(png_ptr, igamma, "png_get_gAMA");
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) &&
+      file_gamma != NULL)
+   {
+      *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
+         "png_get_gAMA");
+      return (PNG_INFO_gAMA);
+   }
 
-   return ok;
+   return (0);
 }
-
 #  endif
 #endif
 
 #ifdef PNG_sRGB_SUPPORTED
 png_uint_32 PNGAPI
-png_get_sRGB(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *file_srgb_intent)
 {
    png_debug1(1, "in %s retrieval function", "sRGB");
@@ -671,7 +691,7 @@ png_get_sRGB(png_const_structp png_ptr, png_const_infop info_ptr,
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
        && file_srgb_intent != NULL)
    {
-      *file_srgb_intent = (int)info_ptr->srgb_intent;
+      *file_srgb_intent = info_ptr->colorspace.rendering_intent;
       return (PNG_INFO_sRGB);
    }
 
@@ -681,7 +701,7 @@ png_get_sRGB(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #ifdef PNG_iCCP_SUPPORTED
 png_uint_32 PNGAPI
-png_get_iCCP(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
     png_charpp name, int *compression_type,
     png_bytepp profile, png_uint_32 *proflen)
 {
@@ -693,11 +713,11 @@ png_get_iCCP(png_const_structp png_ptr, png_const_infop info_ptr,
    {
       *name = info_ptr->iccp_name;
       *profile = info_ptr->iccp_profile;
-      /* Compression_type is a dummy so the API won't have to change
-       * if we introduce multiple compression types later.
+      *proflen = png_get_uint_32(info_ptr->iccp_profile);
+      /* This is somewhat irrelevant since the profile data returned has
+       * actually been uncompressed.
        */
-      *proflen = info_ptr->iccp_proflen;
-      *compression_type = info_ptr->iccp_compression;
+      *compression_type = PNG_COMPRESSION_TYPE_BASE;
       return (PNG_INFO_iCCP);
    }
 
@@ -706,14 +726,14 @@ png_get_iCCP(png_const_structp png_ptr, png_const_infop info_ptr,
 #endif
 
 #ifdef PNG_sPLT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_sPLT(png_const_structp png_ptr, png_const_infop info_ptr,
+int PNGAPI
+png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
     png_sPLT_tpp spalettes)
 {
    if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
    {
       *spalettes = info_ptr->splt_palettes;
-      return ((png_uint_32)info_ptr->splt_palettes_num);
+      return info_ptr->splt_palettes_num;
    }
 
    return (0);
@@ -722,7 +742,7 @@ png_get_sPLT(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #ifdef PNG_hIST_SUPPORTED
 png_uint_32 PNGAPI
-png_get_hIST(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
     png_uint_16p *hist)
 {
    png_debug1(1, "in %s retrieval function", "hIST");
@@ -739,11 +759,10 @@ png_get_hIST(png_const_structp png_ptr, png_const_infop info_ptr,
 #endif
 
 png_uint_32 PNGAPI
-png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
+png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_uint_32 *width, png_uint_32 *height, int *bit_depth,
     int *color_type, int *interlace_type, int *compression_type,
     int *filter_type)
-
 {
    png_debug1(1, "in %s retrieval function", "IHDR");
 
@@ -770,7 +789,7 @@ png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
     * application has ignored our advice not to mess with the members
     * of info_ptr directly.
     */
-   png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
+   png_check_IHDR(png_ptr, info_ptr->width, info_ptr->height,
        info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
        info_ptr->compression_type, info_ptr->filter_type);
 
@@ -779,7 +798,7 @@ png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
 
 #ifdef PNG_oFFs_SUPPORTED
 png_uint_32 PNGAPI
-png_get_oFFs(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
 {
    png_debug1(1, "in %s retrieval function", "oFFs");
@@ -799,7 +818,7 @@ png_get_oFFs(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #ifdef PNG_pCAL_SUPPORTED
 png_uint_32 PNGAPI
-png_get_pCAL(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
     png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
     png_charp *units, png_charpp *params)
 {
@@ -825,16 +844,20 @@ png_get_pCAL(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #ifdef PNG_sCAL_SUPPORTED
 #  ifdef PNG_FIXED_POINT_SUPPORTED
-#    ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
+#    if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
+         defined(PNG_FLOATING_POINT_SUPPORTED)
 png_uint_32 PNGAPI
-png_get_sCAL_fixed(png_structp png_ptr, png_const_infop info_ptr,
+png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, png_fixed_point *width, png_fixed_point *height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
        (info_ptr->valid & PNG_INFO_sCAL))
    {
       *unit = info_ptr->scal_unit;
-      /*TODO: make this work without FP support */
+      /*TODO: make this work without FP support; the API is currently eliminated
+       * if neither floating point APIs nor internal floating point arithmetic
+       * are enabled.
+       */
       *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
       *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
          "sCAL height");
@@ -847,7 +870,7 @@ png_get_sCAL_fixed(png_structp png_ptr, png_const_infop info_ptr,
 #  endif /* FIXED_POINT */
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32 PNGAPI
-png_get_sCAL(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, double *width, double *height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
@@ -863,7 +886,7 @@ png_get_sCAL(png_const_structp png_ptr, png_const_infop info_ptr,
 }
 #  endif /* FLOATING POINT */
 png_uint_32 PNGAPI
-png_get_sCAL_s(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, png_charpp width, png_charpp height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
@@ -881,7 +904,7 @@ png_get_sCAL_s(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #ifdef PNG_pHYs_SUPPORTED
 png_uint_32 PNGAPI
-png_get_pHYs(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
 {
    png_uint_32 retval = 0;
@@ -915,7 +938,7 @@ png_get_pHYs(png_const_structp png_ptr, png_const_infop info_ptr,
 #endif /* pHYs */
 
 png_uint_32 PNGAPI
-png_get_PLTE(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
     png_colorp *palette, int *num_palette)
 {
    png_debug1(1, "in %s retrieval function", "PLTE");
@@ -934,7 +957,7 @@ png_get_PLTE(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #ifdef PNG_sBIT_SUPPORTED
 png_uint_32 PNGAPI
-png_get_sBIT(png_const_structp png_ptr, png_infop info_ptr,
+png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
     png_color_8p *sig_bit)
 {
    png_debug1(1, "in %s retrieval function", "sBIT");
@@ -951,8 +974,8 @@ png_get_sBIT(png_const_structp png_ptr, png_infop info_ptr,
 #endif
 
 #ifdef PNG_TEXT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_text(png_const_structp png_ptr, png_const_infop info_ptr,
+int PNGAPI
+png_get_text(png_const_structrp png_ptr, png_inforp info_ptr,
     png_textp *text_ptr, int *num_text)
 {
    if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
@@ -966,7 +989,7 @@ png_get_text(png_const_structp png_ptr, png_const_infop info_ptr,
       if (num_text != NULL)
          *num_text = info_ptr->num_text;
 
-      return ((png_uint_32)info_ptr->num_text);
+      return info_ptr->num_text;
    }
 
    if (num_text != NULL)
@@ -978,7 +1001,8 @@ png_get_text(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #ifdef PNG_tIME_SUPPORTED
 png_uint_32 PNGAPI
-png_get_tIME(png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
+png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
+    png_timep *mod_time)
 {
    png_debug1(1, "in %s retrieval function", "tIME");
 
@@ -995,7 +1019,7 @@ png_get_tIME(png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
 
 #ifdef PNG_tRNS_SUPPORTED
 png_uint_32 PNGAPI
-png_get_tRNS(png_const_structp png_ptr, png_infop info_ptr,
+png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
     png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
 {
    png_uint_32 retval = 0;
@@ -1038,9 +1062,9 @@ png_get_tRNS(png_const_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 int PNGAPI
-png_get_unknown_chunks(png_const_structp png_ptr, png_const_infop info_ptr,
+png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
     png_unknown_chunkpp unknowns)
 {
    if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
@@ -1055,7 +1079,7 @@ png_get_unknown_chunks(png_const_structp png_ptr, png_const_infop info_ptr,
 
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 png_byte PNGAPI
-png_get_rgb_to_gray_status (png_const_structp png_ptr)
+png_get_rgb_to_gray_status (png_const_structrp png_ptr)
 {
    return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
 }
@@ -1063,43 +1087,60 @@ png_get_rgb_to_gray_status (png_const_structp png_ptr)
 
 #ifdef PNG_USER_CHUNKS_SUPPORTED
 png_voidp PNGAPI
-png_get_user_chunk_ptr(png_const_structp png_ptr)
+png_get_user_chunk_ptr(png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_chunk_ptr : NULL);
 }
 #endif
 
 png_size_t PNGAPI
-png_get_compression_buffer_size(png_const_structp png_ptr)
+png_get_compression_buffer_size(png_const_structrp png_ptr)
 {
-   return (png_ptr ? png_ptr->zbuf_size : 0);
+   if (png_ptr == NULL)
+      return 0;
+
+#  ifdef PNG_WRITE_SUPPORTED
+      if (png_ptr->mode & PNG_IS_READ_STRUCT)
+#  endif
+   {
+#     ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+         return png_ptr->IDAT_read_size;
+#     else
+         return PNG_IDAT_READ_SIZE;
+#     endif
+   }
+
+#  ifdef PNG_WRITE_SUPPORTED
+      else
+         return png_ptr->zbuffer_size;
+#  endif
 }
 
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
 /* These functions were added to libpng 1.2.6 and were enabled
  * by default in libpng-1.4.0 */
 png_uint_32 PNGAPI
-png_get_user_width_max (png_const_structp png_ptr)
+png_get_user_width_max (png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_width_max : 0);
 }
 
 png_uint_32 PNGAPI
-png_get_user_height_max (png_const_structp png_ptr)
+png_get_user_height_max (png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_height_max : 0);
 }
 
 /* This function was added to libpng 1.4.0 */
 png_uint_32 PNGAPI
-png_get_chunk_cache_max (png_const_structp png_ptr)
+png_get_chunk_cache_max (png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
 }
 
 /* This function was added to libpng 1.4.1 */
 png_alloc_size_t PNGAPI
-png_get_chunk_malloc_max (png_const_structp png_ptr)
+png_get_chunk_malloc_max (png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
 }
@@ -1108,23 +1149,16 @@ png_get_chunk_malloc_max (png_const_structp png_ptr)
 /* These functions were added to libpng 1.4.0 */
 #ifdef PNG_IO_STATE_SUPPORTED
 png_uint_32 PNGAPI
-png_get_io_state (png_structp png_ptr)
+png_get_io_state (png_const_structrp png_ptr)
 {
    return png_ptr->io_state;
 }
 
 png_uint_32 PNGAPI
-png_get_io_chunk_type (png_const_structp png_ptr)
+png_get_io_chunk_type (png_const_structrp png_ptr)
 {
    return png_ptr->chunk_name;
 }
-
-png_const_bytep PNGAPI
-png_get_io_chunk_name (png_structp png_ptr)
-{
-   PNG_CSTRING_FROM_CHUNK(png_ptr->io_chunk_string, png_ptr->chunk_name);
-   return png_ptr->io_chunk_string;
-}
 #endif /* ?PNG_IO_STATE_SUPPORTED */
 
 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED

pnginfo.h

@@ -1,11 +1,11 @@
 
 /* pnginfo.h - header file for PNG reference library
  *
- * 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 1.6.1 [March 28, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -55,7 +55,7 @@
 
 struct png_info_def
 {
-   /* the following are necessary for every PNG file */
+   /* The following are necessary for every PNG file */
    png_uint_32 width;  /* width of image in pixels (from IHDR) */
    png_uint_32 height; /* height of image in pixels (from IHDR) */
    png_uint_32 valid;  /* valid chunk data (see PNG_INFO_ below) */
@@ -70,11 +70,17 @@ struct png_info_def
    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
 
-   /* The following is informational only on read, and not used on writes. */
+   /* The following are set by png_set_IHDR, called from the application on
+    * write, but the are never actually used by the write code.
+    */
    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
    png_byte pixel_depth;    /* number of bits per pixel */
    png_byte spare_byte;     /* to align the data, and for future use */
+
+#ifdef PNG_READ_SUPPORTED
+   /* This is never set during write */
    png_byte signature[8];   /* magic bytes read by libpng from start of file */
+#endif
 
    /* The rest of the data is optional.  If you are reading, check the
     * valid field to see if the information in these are valid.  If you
@@ -82,18 +88,25 @@ struct png_info_def
     * and initialize the appropriate fields below.
     */
 
-#if defined(PNG_gAMA_SUPPORTED)
-   /* The gAMA chunk describes the gamma characteristics of the system
-    * on which the image was created, normally in the range [1.0, 2.5].
-    * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+   /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are
+    * defined.  When COLORSPACE is switched on all the colorspace-defining
+    * chunks should be enabled, when GAMMA is switched on all the gamma-defining
+    * chunks should be enabled.  If this is not done it becomes possible to read
+    * inconsistent PNG files and assign a probably incorrect interpretation to
+    * the information.  (In other words, by carefully choosing which chunks to
+    * recognize the system configuration can select an interpretation for PNG
+    * files containing ambiguous data and this will result in inconsistent
+    * behavior between different libpng builds!)
     */
-   png_fixed_point gamma;
+   png_colorspace colorspace;
 #endif
 
-#ifdef PNG_sRGB_SUPPORTED
-    /* GR-P, 0.96a */
-    /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
-   png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
+#ifdef PNG_iCCP_SUPPORTED
+   /* iCCP chunk data. */
+   png_charp iccp_name;     /* profile name */
+   png_bytep iccp_profile;  /* International Color Consortium profile data */
+   png_uint_32 iccp_proflen;  /* ICC profile data length */
 #endif
 
 #ifdef PNG_TEXT_SUPPORTED
@@ -183,23 +196,6 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
    png_uint_16p hist;
 #endif
 
-#ifdef PNG_cHRM_SUPPORTED
-   /* The cHRM chunk describes the CIE color characteristics of the monitor
-    * on which the PNG was created.  This data allows the viewer to do gamut
-    * mapping of the input image to ensure that the viewer sees the same
-    * colors in the image as the creator.  Values are in the range
-    * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
-    */
-   png_fixed_point x_white;
-   png_fixed_point y_white;
-   png_fixed_point x_red;
-   png_fixed_point y_red;
-   png_fixed_point x_green;
-   png_fixed_point y_green;
-   png_fixed_point x_blue;
-   png_fixed_point y_blue;
-#endif
-
 #ifdef PNG_pCAL_SUPPORTED
    /* The pCAL chunk describes a transformation between the stored pixel
     * values and original physical data values used to create the image.
@@ -224,25 +220,20 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
 /* New members added in libpng-1.0.6 */
    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
- defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
    /* Storage for unknown chunks that the library doesn't recognize. */
    png_unknown_chunkp unknown_chunks;
-   int unknown_chunks_num;
-#endif
 
-#ifdef PNG_iCCP_SUPPORTED
-   /* iCCP chunk data. */
-   png_charp iccp_name;     /* profile name */
-   png_bytep iccp_profile;  /* International Color Consortium profile data */
-   png_uint_32 iccp_proflen;  /* ICC profile data length */
-   png_byte iccp_compression; /* Always zero */
+   /* The type of this field is limited by the type of 
+    * png_struct::user_chunk_cache_max, else overflow can occur.
+    */
+   int                unknown_chunks_num;
 #endif
 
 #ifdef PNG_sPLT_SUPPORTED
    /* Data on sPLT chunks (there may be more than one). */
    png_sPLT_tp splt_palettes;
-   int splt_palettes_num;
+   int         splt_palettes_num; /* Match type returned by png_get API */
 #endif
 
 #ifdef PNG_sCAL_SUPPORTED

pngmem.c

@@ -1,8 +1,8 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.5.13 [September 27, 2012]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
+ * 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.)
  *
@@ -20,457 +20,23 @@
 #include "pngpriv.h"
 
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
-
-/* Borland DOS special memory handler */
-#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-/* If you change this, be sure to change the one in png.h also */
-
-/* Allocate memory for a png_struct.  The malloc and memset can be replaced
-   by a single call to calloc() if this is thought to improve performance. */
-PNG_FUNCTION(png_voidp /* PRIVATE */,
-png_create_struct,(int type),PNG_ALLOCATED)
-{
-#  ifdef PNG_USER_MEM_SUPPORTED
-   return (png_create_struct_2(type, NULL, NULL));
-}
-
-/* Alternate version of png_create_struct, for use with user-defined malloc. */
-PNG_FUNCTION(png_voidp /* PRIVATE */,
-png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
-   PNG_ALLOCATED)
-{
-#  endif /* PNG_USER_MEM_SUPPORTED */
-   png_size_t size;
-   png_voidp struct_ptr;
-
-   if (type == PNG_STRUCT_INFO)
-      size = png_sizeof(png_info);
-
-   else if (type == PNG_STRUCT_PNG)
-      size = png_sizeof(png_struct);
-
-   else
-      return (png_get_copyright(NULL));
-
-#  ifdef PNG_USER_MEM_SUPPORTED
-   if (malloc_fn != NULL)
-   {
-      png_struct dummy_struct;
-      png_memset(&dummy_struct, 0, sizeof dummy_struct);
-      dummy_struct.mem_ptr=mem_ptr;
-      struct_ptr = (*(malloc_fn))(&dummy_struct, (png_alloc_size_t)size);
-   }
-
-   else
-#  endif /* PNG_USER_MEM_SUPPORTED */
-   struct_ptr = (png_voidp)farmalloc(size);
-   if (struct_ptr != NULL)
-      png_memset(struct_ptr, 0, size);
-
-   return (struct_ptr);
-}
-
-/* Free memory allocated by a png_create_struct() call */
+/* Free a png_struct */
 void /* PRIVATE */
-png_destroy_struct(png_voidp struct_ptr)
+png_destroy_png_struct(png_structrp png_ptr)
 {
-#  ifdef PNG_USER_MEM_SUPPORTED
-   png_destroy_struct_2(struct_ptr, NULL, NULL);
-}
-
-/* Free memory allocated by a png_create_struct() call */
-void /* PRIVATE */
-png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
-    png_voidp mem_ptr)
-{
-#  endif
-   if (struct_ptr != NULL)
+   if (png_ptr != NULL)
    {
-#  ifdef PNG_USER_MEM_SUPPORTED
-      if (free_fn != NULL)
-      {
-         png_struct dummy_struct;
-         png_memset(&dummy_struct, 0, sizeof dummy_struct);
-         dummy_struct.mem_ptr=mem_ptr;
-         (*(free_fn))(&dummy_struct, struct_ptr);
-         return;
-      }
-
-#  endif /* PNG_USER_MEM_SUPPORTED */
-      farfree (struct_ptr);
-   }
-}
-
-/* Allocate memory.  For reasonable files, size should never exceed
- * 64K.  However, zlib may allocate more then 64K if you don't tell
- * it not to.  See zconf.h and png.h for more information. zlib does
- * need to allocate exactly 64K, so whatever you call here must
- * have the ability to do that.
- *
- * Borland seems to have a problem in DOS mode for exactly 64K.
- * It gives you a segment with an offset of 8 (perhaps to store its
- * memory stuff).  zlib doesn't like this at all, so we have to
- * detect and deal with it.  This code should not be needed in
- * Windows or OS/2 modes, and only in 16 bit mode.  This code has
- * been updated by Alexander Lehmann for version 0.89 to waste less
- * memory.
- *
- * Note that we can't use png_size_t for the "size" declaration,
- * since on some systems a png_size_t is a 16-bit quantity, and as a
- * result, we would be truncating potentially larger memory requests
- * (which should cause a fatal error) and introducing major problems.
- */
-PNG_FUNCTION(png_voidp,PNGAPI
-png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
-{
-   png_voidp ret;
-
-   ret = (png_malloc(png_ptr, size));
-
-   if (ret != NULL)
-      png_memset(ret,0,(png_size_t)size);
-
-   return (ret);
-}
-
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
-{
-   png_voidp ret;
-
-   if (png_ptr == NULL || size == 0)
-      return (NULL);
-
-#  ifdef PNG_USER_MEM_SUPPORTED
-   if (png_ptr->malloc_fn != NULL)
-      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
-
-   else
-      ret = (png_malloc_default(png_ptr, size));
-
-   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-       png_error(png_ptr, "Out of memory");
-
-   return (ret);
-}
-
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
-{
-   png_voidp ret;
-#  endif /* PNG_USER_MEM_SUPPORTED */
-
-   if (png_ptr == NULL || size == 0)
-      return (NULL);
-
-#  ifdef PNG_MAX_MALLOC_64K
-   if (size > (png_uint_32)65536L)
-   {
-      png_warning(png_ptr, "Cannot Allocate > 64K");
-      ret = NULL;
-   }
-
-   else
-#  endif
-
-   if (size != (size_t)size)
-      ret = NULL;
-
-   else if (size == (png_uint_32)65536L)
-   {
-      if (png_ptr->offset_table == NULL)
-      {
-         /* Try to see if we need to do any of this fancy stuff */
-         ret = farmalloc(size);
-         if (ret == NULL || ((png_size_t)ret & 0xffff))
-         {
-            int num_blocks;
-            png_uint_32 total_size;
-            png_bytep table;
-            int i, mem_level, window_bits;
-            png_byte huge * hptr;
-            int window_bits
-
-            if (ret != NULL)
-            {
-               farfree(ret);
-               ret = NULL;
-            }
-
-            window_bits =
-                png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ?
-                png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits;
-
-            if (window_bits > 14)
-               num_blocks = (int)(1 << (window_bits - 14));
-
-            else
-               num_blocks = 1;
-
-            mem_level =
-                png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ?
-                png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level;
-
-            if (mem_level >= 7)
-               num_blocks += (int)(1 << (mem_level - 7));
-
-            else
-               num_blocks++;
-
-            total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
-
-            table = farmalloc(total_size);
-
-            if (table == NULL)
-            {
-#  ifndef PNG_USER_MEM_SUPPORTED
-               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-                  png_error(png_ptr, "Out Of Memory"); /* Note "O", "M" */
-
-               else
-                  png_warning(png_ptr, "Out Of Memory");
-#  endif
-               return (NULL);
-            }
-
-            if ((png_size_t)table & 0xfff0)
-            {
-#  ifndef PNG_USER_MEM_SUPPORTED
-               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-                  png_error(png_ptr,
-                    "Farmalloc didn't return normalized pointer");
-
-               else
-                  png_warning(png_ptr,
-                    "Farmalloc didn't return normalized pointer");
-#  endif
-               return (NULL);
-            }
-
-            png_ptr->offset_table = table;
-            png_ptr->offset_table_ptr = farmalloc(num_blocks *
-               png_sizeof(png_bytep));
-
-            if (png_ptr->offset_table_ptr == NULL)
-            {
-#  ifndef PNG_USER_MEM_SUPPORTED
-               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-                  png_error(png_ptr, "Out Of memory"); /* Note "O", "m" */
-
-               else
-                  png_warning(png_ptr, "Out Of memory");
-#  endif
-               return (NULL);
-            }
-
-            hptr = (png_byte huge *)table;
-            if ((png_size_t)hptr & 0xf)
-            {
-               hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
-               hptr = hptr + 16L;  /* "hptr += 16L" fails on Turbo C++ 3.0 */
-            }
-
-            for (i = 0; i < num_blocks; i++)
-            {
-               png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
-               hptr = hptr + (png_uint_32)65536L;  /* "+=" fails on TC++3.0 */
-            }
-
-            png_ptr->offset_table_number = num_blocks;
-            png_ptr->offset_table_count = 0;
-            png_ptr->offset_table_count_free = 0;
-         }
-      }
-
-      if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
-      {
-#  ifndef PNG_USER_MEM_SUPPORTED
-         if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-            png_error(png_ptr, "Out of Memory"); /* Note "O" and "M" */
-
-         else
-            png_warning(png_ptr, "Out of Memory");
-#  endif
-         return (NULL);
-      }
-
-      ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
-   }
-
-   else
-      ret = farmalloc(size);
-
-#  ifndef PNG_USER_MEM_SUPPORTED
-   if (ret == NULL)
-   {
-      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-         png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */
-
-      else
-         png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */
-   }
-#  endif
-
-   return (ret);
-}
-
-/* Free a pointer allocated by png_malloc().  In the default
- * configuration, png_ptr is not used, but is passed in case it
- * is needed.  If ptr is NULL, return without taking any action.
- */
-void PNGAPI
-png_free(png_structp png_ptr, png_voidp ptr)
-{
-   if (png_ptr == NULL || ptr == NULL)
-      return;
-
-#  ifdef PNG_USER_MEM_SUPPORTED
-   if (png_ptr->free_fn != NULL)
-   {
-      (*(png_ptr->free_fn))(png_ptr, ptr);
-      return;
-   }
-
-   else
-      png_free_default(png_ptr, ptr);
-}
-
-void PNGAPI
-png_free_default(png_structp png_ptr, png_voidp ptr)
-{
-#  endif /* PNG_USER_MEM_SUPPORTED */
-
-   if (png_ptr == NULL || ptr == NULL)
-      return;
-
-   if (png_ptr->offset_table != NULL)
-   {
-      int i;
-
-      for (i = 0; i < png_ptr->offset_table_count; i++)
-      {
-         if (ptr == png_ptr->offset_table_ptr[i])
-         {
-            ptr = NULL;
-            png_ptr->offset_table_count_free++;
-            break;
-         }
-      }
-      if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
-      {
-         farfree(png_ptr->offset_table);
-         farfree(png_ptr->offset_table_ptr);
-         png_ptr->offset_table = NULL;
-         png_ptr->offset_table_ptr = NULL;
-      }
-   }
-
-   if (ptr != NULL)
-      farfree(ptr);
-}
-
-#else /* Not the Borland DOS special memory handler */
-
-/* Allocate memory for a png_struct or a png_info.  The malloc and
-   memset can be replaced by a single call to calloc() if this is thought
-   to improve performance noticably. */
-PNG_FUNCTION(png_voidp /* PRIVATE */,
-png_create_struct,(int type),PNG_ALLOCATED)
-{
-#  ifdef PNG_USER_MEM_SUPPORTED
-   return (png_create_struct_2(type, NULL, NULL));
-}
-
-/* Allocate memory for a png_struct or a png_info.  The malloc and
-   memset can be replaced by a single call to calloc() if this is thought
-   to improve performance noticably. */
-PNG_FUNCTION(png_voidp /* PRIVATE */,
-png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
-   PNG_ALLOCATED)
-{
-#  endif /* PNG_USER_MEM_SUPPORTED */
-   png_size_t size;
-   png_voidp struct_ptr;
-
-   if (type == PNG_STRUCT_INFO)
-      size = png_sizeof(png_info);
-
-   else if (type == PNG_STRUCT_PNG)
-      size = png_sizeof(png_struct);
-
-   else
-      return (NULL);
-
-#  ifdef PNG_USER_MEM_SUPPORTED
-   if (malloc_fn != NULL)
-   {
-      png_struct dummy_struct;
-      png_structp png_ptr = &dummy_struct;
-      png_ptr->mem_ptr=mem_ptr;
-      struct_ptr = (*(malloc_fn))(png_ptr, size);
-
-      if (struct_ptr != NULL)
-         png_memset(struct_ptr, 0, size);
-
-      return (struct_ptr);
-   }
-#  endif /* PNG_USER_MEM_SUPPORTED */
-
-#  if defined(__TURBOC__) && !defined(__FLAT__)
-   struct_ptr = (png_voidp)farmalloc(size);
-#  else
-#    if defined(_MSC_VER) && defined(MAXSEG_64K)
-   struct_ptr = (png_voidp)halloc(size, 1);
-#    else
-   struct_ptr = (png_voidp)malloc(size);
-#    endif
-#  endif
-
-   if (struct_ptr != NULL)
-      png_memset(struct_ptr, 0, size);
-
-   return (struct_ptr);
-}
-
-
-/* Free memory allocated by a png_create_struct() call */
-void /* PRIVATE */
-png_destroy_struct(png_voidp struct_ptr)
-{
-#  ifdef PNG_USER_MEM_SUPPORTED
-   png_destroy_struct_2(struct_ptr, NULL, NULL);
-}
-
-/* Free memory allocated by a png_create_struct() call */
-void /* PRIVATE */
-png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
-    png_voidp mem_ptr)
-{
-#  endif /* PNG_USER_MEM_SUPPORTED */
-   if (struct_ptr != NULL)
-   {
-#  ifdef PNG_USER_MEM_SUPPORTED
-      if (free_fn != NULL)
-      {
-         png_struct dummy_struct;
-         png_structp png_ptr = &dummy_struct;
-         png_ptr->mem_ptr=mem_ptr;
-         (*(free_fn))(png_ptr, struct_ptr);
-         return;
-      }
-#  endif /* PNG_USER_MEM_SUPPORTED */
-#  if defined(__TURBOC__) && !defined(__FLAT__)
-      farfree(struct_ptr);
-
-#  else
-#    if defined(_MSC_VER) && defined(MAXSEG_64K)
-      hfree(struct_ptr);
-
-#    else
-      free(struct_ptr);
-
-#    endif
-#  endif
+      /* png_free might call png_error and may certainly call
+       * png_get_mem_ptr, so fake a temporary png_struct to support this.
+       */
+      png_struct dummy_struct = *png_ptr;
+      memset(png_ptr, 0, (sizeof *png_ptr));
+      png_free(&dummy_struct, png_ptr);
+
+#     ifdef PNG_SETJMP_SUPPORTED
+         /* We may have a jmp_buf left to deallocate. */
+         png_free_jmpbuf(&dummy_struct);
+#     endif
    }
 }
 
@@ -480,167 +46,215 @@ png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
  * need to allocate exactly 64K, so whatever you call here must
  * have the ability to do that.
  */
-
 PNG_FUNCTION(png_voidp,PNGAPI
-png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
 {
    png_voidp ret;
 
-   ret = (png_malloc(png_ptr, size));
+   ret = png_malloc(png_ptr, size);
 
    if (ret != NULL)
-      png_memset(ret,0,(png_size_t)size);
+      memset(ret, 0, size);
 
-   return (ret);
+   return ret;
 }
 
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
+ * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
+ * Checking and error handling must happen outside this routine; it returns NULL
+ * if the allocation cannot be done (for any reason.)
+ */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
+   PNG_ALLOCATED)
 {
-   png_voidp ret;
+   /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
+    * allocators have also been removed in 1.6.0, so any 16-bit system now has
+    * to implement a user memory handler.  This checks to be sure it isn't
+    * called with big numbers.
+    */
+#ifndef PNG_USER_MEM_SUPPORTED
+   PNG_UNUSED(png_ptr)
+#endif
 
-#  ifdef PNG_USER_MEM_SUPPORTED
-   if (png_ptr == NULL || size == 0)
-      return (NULL);
-
-   if (png_ptr->malloc_fn != NULL)
-      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
-
-   else
-      ret = (png_malloc_default(png_ptr, size));
-
-   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-       png_error(png_ptr, "Out of Memory");
-
-   return (ret);
-}
-
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
-{
-   png_voidp ret;
-#  endif /* PNG_USER_MEM_SUPPORTED */
-
-   if (png_ptr == NULL || size == 0)
-      return (NULL);
-
-#  ifdef PNG_MAX_MALLOC_64K
-   if (size > (png_uint_32)65536L)
+   if (size > 0 && size <= PNG_SIZE_MAX
+#     ifdef PNG_MAX_MALLOC_64K
+         && size <= 65536U
+#     endif
+      )
    {
-#    ifndef PNG_USER_MEM_SUPPORTED
-      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-         png_error(png_ptr, "Cannot Allocate > 64K");
+#ifdef PNG_USER_MEM_SUPPORTED
+      if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
+         return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
 
       else
-#    endif
-         return NULL;
+#endif
+         return malloc((size_t)size); /* checked for truncation above */
    }
-#  endif
-
-   /* Check for overflow */
-#  if defined(__TURBOC__) && !defined(__FLAT__)
-
-   if (size != (unsigned long)size)
-      ret = NULL;
 
    else
-      ret = farmalloc(size);
+      return NULL;
+}
 
-#  else
-#    if defined(_MSC_VER) && defined(MAXSEG_64K)
-   if (size != (unsigned long)size)
-      ret = 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.
+ */
+static png_voidp
+png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
+   size_t element_size)
+{
+   png_alloc_size_t req = nelements; /* known to be > 0 */
 
-   else
-      ret = halloc(size, 1);
+   if (req <= PNG_SIZE_MAX/element_size)
+      return png_malloc_base(png_ptr, req * element_size);
 
-#    else
-   if (size != (size_t)size)
-      ret = NULL;
+   /* The failure case when the request is too large */
+   return NULL;
+}
 
-   else
-      ret = malloc((size_t)size);
-#    endif
-#  endif
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+   size_t element_size),PNG_ALLOCATED)
+{
+   if (nelements <= 0 || element_size == 0)
+      png_error(png_ptr, "internal error: array alloc");
 
-#  ifndef PNG_USER_MEM_SUPPORTED
-   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
-      png_error(png_ptr, "Out of Memory");
-#  endif
+   return png_malloc_array_checked(png_ptr, nelements, element_size);
+}
 
-   return (ret);
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
+   int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
+{
+   /* These are internal errors: */
+   if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+      (old_array == NULL && old_elements > 0))
+      png_error(png_ptr, "internal error: array realloc");
+
+   /* Check for overflow on the elements count (so the caller does not have to
+    * check.)
+    */
+   if (add_elements <= INT_MAX - old_elements)
+   {
+      png_voidp new_array = png_malloc_array_checked(png_ptr,
+         old_elements+add_elements, element_size);
+
+      if (new_array != NULL)
+      {
+         /* Because png_malloc_array worked the size calculations below cannot
+          * overflow.
+          */
+         if (old_elements > 0)
+            memcpy(new_array, old_array, element_size*(unsigned)old_elements);
+
+         memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+            element_size*(unsigned)add_elements);
+
+         return new_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
+ * function png_malloc_default is also provided.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
+{
+   png_voidp ret;
+
+   if (png_ptr == NULL)
+      return NULL;
+
+   ret = png_malloc_base(png_ptr, size);
+
+   if (ret == NULL)
+       png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
+
+   return ret;
+}
+
+#ifdef PNG_USER_MEM_SUPPORTED
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
+   PNG_ALLOCATED PNG_DEPRECATED)
+{
+   png_voidp ret;
+
+   if (png_ptr == NULL)
+      return NULL;
+
+   /* Passing 'NULL' here bypasses the application provided memory handler. */
+   ret = png_malloc_base(NULL/*use malloc*/, size);
+
+   if (ret == NULL)
+      png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
+
+   return ret;
+}
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
+ * function will issue a png_warning and return NULL instead of issuing a
+ * png_error, if it fails to allocate the requested memory.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
+   PNG_ALLOCATED)
+{
+   if (png_ptr != NULL)
+   {
+      png_voidp ret = png_malloc_base(png_ptr, size);
+
+      if (ret != NULL)
+         return ret;
+
+      png_warning(png_ptr, "Out of memory");
+   }
+
+   return NULL;
 }
 
 /* Free a pointer allocated by png_malloc().  If ptr is NULL, return
  * without taking any action.
  */
 void PNGAPI
-png_free(png_structp png_ptr, png_voidp ptr)
+png_free(png_const_structrp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
 
-#  ifdef PNG_USER_MEM_SUPPORTED
+#ifdef PNG_USER_MEM_SUPPORTED
    if (png_ptr->free_fn != NULL)
-   {
-      (*(png_ptr->free_fn))(png_ptr, ptr);
-      return;
-   }
+      png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
 
    else
       png_free_default(png_ptr, ptr);
 }
 
-void PNGAPI
-png_free_default(png_structp png_ptr, png_voidp ptr)
+PNG_FUNCTION(void,PNGAPI
+png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
+#endif /* PNG_USER_MEM_SUPPORTED */
 
-#  endif /* PNG_USER_MEM_SUPPORTED */
-
-#  if defined(__TURBOC__) && !defined(__FLAT__)
-   farfree(ptr);
-
-#  else
-#    if defined(_MSC_VER) && defined(MAXSEG_64K)
-   hfree(ptr);
-
-#    else
    free(ptr);
-
-#    endif
-#  endif
 }
-#endif /* Not Borland DOS special memory handler */
-
-/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
- * function will set up png_malloc() to issue a png_warning and return NULL
- * instead of issuing a png_error, if it fails to allocate the requested
- * memory.
- */
-PNG_FUNCTION(png_voidp,PNGAPI
-png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
-{
-   png_voidp ptr;
-   png_uint_32 save_flags;
-   if (png_ptr == NULL)
-      return (NULL);
-
-   save_flags = png_ptr->flags;
-   png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
-   ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
-   png_ptr->flags=save_flags;
-   return(ptr);
-}
-
 
 #ifdef PNG_USER_MEM_SUPPORTED
 /* This function is called when the application wants to use another method
  * of allocating and freeing memory.
  */
 void PNGAPI
-png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
   malloc_fn, png_free_ptr free_fn)
 {
    if (png_ptr != NULL)
@@ -656,12 +270,12 @@ png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
  * pointer before png_write_destroy and png_read_destroy are called.
  */
 png_voidp PNGAPI
-png_get_mem_ptr(png_const_structp png_ptr)
+png_get_mem_ptr(png_const_structrp png_ptr)
 {
    if (png_ptr == NULL)
-      return (NULL);
+      return NULL;
 
-   return ((png_voidp)png_ptr->mem_ptr);
+   return png_ptr->mem_ptr;
 }
 #endif /* PNG_USER_MEM_SUPPORTED */
 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

pngpread.c

@@ -1,8 +1,8 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.5.11 [June 14, 2012]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
+ * 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.)
  *
@@ -27,7 +27,7 @@
 #define PNG_ERROR_MODE      8
 
 void PNGAPI
-png_process_data(png_structp png_ptr, png_infop info_ptr,
+png_process_data(png_structrp png_ptr, png_inforp info_ptr,
     png_bytep buffer, png_size_t buffer_size)
 {
    if (png_ptr == NULL || info_ptr == NULL)
@@ -42,7 +42,7 @@ png_process_data(png_structp png_ptr, png_infop info_ptr,
 }
 
 png_size_t PNGAPI
-png_process_data_pause(png_structp png_ptr, int save)
+png_process_data_pause(png_structrp png_ptr, int save)
 {
    if (png_ptr != NULL)
    {
@@ -69,7 +69,7 @@ png_process_data_pause(png_structp png_ptr, int save)
 }
 
 png_uint_32 PNGAPI
-png_process_data_skip(png_structp png_ptr)
+png_process_data_skip(png_structrp png_ptr)
 {
    png_uint_32 remaining = 0;
 
@@ -103,7 +103,7 @@ png_process_data_skip(png_structp png_ptr)
  * doing before we ran out of data...
  */
 void /* PRIVATE */
-png_process_some_data(png_structp png_ptr, png_infop info_ptr)
+png_process_some_data(png_structrp png_ptr, png_inforp info_ptr)
 {
    if (png_ptr == NULL)
       return;
@@ -149,10 +149,10 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
  * routine.
  */
 void /* PRIVATE */
-png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
+png_push_read_sig(png_structrp png_ptr, png_inforp info_ptr)
 {
    png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */ 
-       num_to_check = 8 - num_checked;
+             num_to_check = 8 - num_checked;
 
    if (png_ptr->buffer_size < num_to_check)
    {
@@ -172,7 +172,6 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
       else
          png_error(png_ptr, "PNG file corrupted by ASCII conversion");
    }
-
    else
    {
       if (png_ptr->sig_bytes >= 8)
@@ -183,9 +182,12 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
 }
 
 void /* PRIVATE */
-png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
+png_push_read_chunk(png_structrp png_ptr, png_inforp info_ptr)
 {
    png_uint_32 chunk_name;
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+   int keep; /* unknown handling method */
+#endif
 
    /* First we make sure we have enough data for the 4 byte chunk name
     * and the 4 byte chunk length before proceeding with decoding the
@@ -217,14 +219,28 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
    if (chunk_name == png_IDAT)
    {
-      /* This is here above the if/else case statement below because if the
-       * unknown handling marks 'IDAT' as unknown then the IDAT handling case is
-       * completely skipped.
-       *
-       * TODO: there must be a better way of doing this.
-       */
       if (png_ptr->mode & PNG_AFTER_IDAT)
          png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+      /* If we reach an IDAT chunk, this means we have read all of the
+       * header chunks, and we can start reading the image (or if this
+       * is called after the image has been read - we have an error).
+       */
+      if (!(png_ptr->mode & PNG_HAVE_IHDR))
+         png_error(png_ptr, "Missing IHDR before IDAT");
+
+      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+          !(png_ptr->mode & PNG_HAVE_PLTE))
+         png_error(png_ptr, "Missing PLTE before IDAT");
+
+      png_ptr->mode |= PNG_HAVE_IDAT;
+
+      if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+         if (png_ptr->push_length == 0)
+            return;
+
+      if (png_ptr->mode & PNG_AFTER_IDAT)
+         png_benign_error(png_ptr, "Too many IDATs found");
    }
 
    if (chunk_name == png_IHDR)
@@ -256,7 +272,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    }
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   else if (png_chunk_unknown_handling(png_ptr, chunk_name))
+   else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)
    {
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
@@ -264,23 +280,10 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
          return;
       }
 
-      if (chunk_name == png_IDAT)
-         png_ptr->mode |= PNG_HAVE_IDAT;
-
-      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep);
 
       if (chunk_name == png_PLTE)
          png_ptr->mode |= PNG_HAVE_PLTE;
-
-      else if (chunk_name == png_IDAT)
-      {
-         if (!(png_ptr->mode & PNG_HAVE_IHDR))
-            png_error(png_ptr, "Missing IHDR before IDAT");
-
-         else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-             !(png_ptr->mode & PNG_HAVE_PLTE))
-            png_error(png_ptr, "Missing PLTE before IDAT");
-      }
    }
 #endif
 
@@ -296,30 +299,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
    else if (chunk_name == png_IDAT)
    {
-      /* If we reach an IDAT chunk, this means we have read all of the
-       * header chunks, and we can start reading the image (or if this
-       * is called after the image has been read - we have an error).
-       */
-
-      if (!(png_ptr->mode & PNG_HAVE_IHDR))
-         png_error(png_ptr, "Missing IHDR before IDAT");
-
-      else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
-          !(png_ptr->mode & PNG_HAVE_PLTE))
-         png_error(png_ptr, "Missing PLTE before IDAT");
-
-      if (png_ptr->mode & PNG_HAVE_IDAT)
-      {
-         if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
-            if (png_ptr->push_length == 0)
-               return;
-
-         if (png_ptr->mode & PNG_AFTER_IDAT)
-            png_benign_error(png_ptr, "Too many IDATs found");
-      }
-
       png_ptr->idat_size = png_ptr->push_length;
-      png_ptr->mode |= PNG_HAVE_IDAT;
       png_ptr->process_mode = PNG_READ_IDAT_MODE;
       png_push_have_info(png_ptr, info_ptr);
       png_ptr->zstream.avail_out =
@@ -548,7 +528,6 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
       png_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
-
 #endif
 
    else
@@ -558,21 +537,22 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
          png_push_save_buffer(png_ptr);
          return;
       }
-      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+      png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length,
+         PNG_HANDLE_CHUNK_AS_DEFAULT);
    }
 
    png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
 }
 
 void /* PRIVATE */
-png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
+png_push_crc_skip(png_structrp png_ptr, png_uint_32 skip)
 {
    png_ptr->process_mode = PNG_SKIP_MODE;
    png_ptr->skip_length = skip;
 }
 
 void /* PRIVATE */
-png_push_crc_finish(png_structp png_ptr)
+png_push_crc_finish(png_structrp png_ptr)
 {
    if (png_ptr->skip_length && png_ptr->save_buffer_size)
    {
@@ -598,7 +578,6 @@ png_push_crc_finish(png_structp png_ptr)
       png_ptr->save_buffer_size -= save_size;
       png_ptr->save_buffer_ptr += save_size;
    }
-
    if (png_ptr->skip_length && png_ptr->current_buffer_size)
    {
       png_size_t save_size = png_ptr->current_buffer_size;
@@ -620,7 +599,6 @@ png_push_crc_finish(png_structp png_ptr)
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
    }
-
    if (!png_ptr->skip_length)
    {
       if (png_ptr->buffer_size < 4)
@@ -643,7 +621,6 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       return;
 
    ptr = buffer;
-
    if (png_ptr->save_buffer_size)
    {
       png_size_t save_size;
@@ -654,14 +631,13 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       else
          save_size = png_ptr->save_buffer_size;
 
-      png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
+      memcpy(ptr, png_ptr->save_buffer_ptr, save_size);
       length -= save_size;
       ptr += save_size;
       png_ptr->buffer_size -= save_size;
       png_ptr->save_buffer_size -= save_size;
       png_ptr->save_buffer_ptr += save_size;
    }
-
    if (length && png_ptr->current_buffer_size)
    {
       png_size_t save_size;
@@ -672,7 +648,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
       else
          save_size = png_ptr->current_buffer_size;
 
-      png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
+      memcpy(ptr, png_ptr->current_buffer_ptr, save_size);
       png_ptr->buffer_size -= save_size;
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
@@ -680,7 +656,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
 }
 
 void /* PRIVATE */
-png_push_save_buffer(png_structp png_ptr)
+png_push_save_buffer(png_structrp png_ptr)
 {
    if (png_ptr->save_buffer_size)
    {
@@ -691,7 +667,6 @@ png_push_save_buffer(png_structp png_ptr)
          png_bytep dp;
 
          istop = png_ptr->save_buffer_size;
-
          for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
              i < istop; i++, sp++, dp++)
          {
@@ -699,7 +674,6 @@ png_push_save_buffer(png_structp png_ptr)
          }
       }
    }
-
    if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
        png_ptr->save_buffer_max)
    {
@@ -714,7 +688,8 @@ png_push_save_buffer(png_structp png_ptr)
 
       new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
       old_buffer = png_ptr->save_buffer;
-      png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr, new_max);
+      png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
+          (png_size_t)new_max);
 
       if (png_ptr->save_buffer == NULL)
       {
@@ -722,25 +697,23 @@ png_push_save_buffer(png_structp png_ptr)
          png_error(png_ptr, "Insufficient memory for save_buffer");
       }
 
-      png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+      memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
       png_free(png_ptr, old_buffer);
       png_ptr->save_buffer_max = new_max;
    }
-
    if (png_ptr->current_buffer_size)
    {
-      png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
+      memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
          png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
       png_ptr->save_buffer_size += png_ptr->current_buffer_size;
       png_ptr->current_buffer_size = 0;
    }
-
    png_ptr->save_buffer_ptr = png_ptr->save_buffer;
    png_ptr->buffer_size = 0;
 }
 
 void /* PRIVATE */
-png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
+png_push_restore_buffer(png_structrp png_ptr, png_bytep buffer,
    png_size_t buffer_length)
 {
    png_ptr->current_buffer = buffer;
@@ -750,7 +723,7 @@ png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
 }
 
 void /* PRIVATE */
-png_push_read_IDAT(png_structp png_ptr)
+png_push_read_IDAT(png_structrp png_ptr)
 {
    if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
    {
@@ -775,7 +748,7 @@ png_push_read_IDAT(png_structp png_ptr)
       {
          png_ptr->process_mode = PNG_READ_CHUNK_MODE;
 
-         if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+         if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
             png_error(png_ptr, "Not enough compressed data");
 
          return;
@@ -836,7 +809,6 @@ png_push_read_IDAT(png_structp png_ptr)
       png_ptr->current_buffer_size -= save_size;
       png_ptr->current_buffer_ptr += save_size;
    }
-
    if (!png_ptr->idat_size)
    {
       if (png_ptr->buffer_size < 4)
@@ -848,11 +820,12 @@ png_push_read_IDAT(png_structp png_ptr)
       png_crc_finish(png_ptr, 0);
       png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
       png_ptr->mode |= PNG_AFTER_IDAT;
+      png_ptr->zowner = 0;
    }
 }
 
 void /* PRIVATE */
-png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
+png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
    png_size_t buffer_length)
 {
    /* The caller checks for a non-zero buffer length. */
@@ -864,13 +837,14 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
     * handle the uncompressed results.
     */
    png_ptr->zstream.next_in = buffer;
+   /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
    png_ptr->zstream.avail_in = (uInt)buffer_length;
 
    /* Keep going until the decompressed data is all processed
     * or the stream marked as finished.
     */
    while (png_ptr->zstream.avail_in > 0 &&
-          !(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+      !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED))
    {
       int ret;
 
@@ -881,9 +855,9 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
        */
       if (!(png_ptr->zstream.avail_out > 0))
       {
-         png_ptr->zstream.avail_out =
-             (uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
-             png_ptr->iwidth) + 1;
+         /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
+         png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
+             png_ptr->iwidth) + 1);
 
          png_ptr->zstream.next_out = png_ptr->row_buf;
       }
@@ -901,7 +875,8 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
       if (ret != Z_OK && ret != Z_STREAM_END)
       {
          /* Terminate the decompression. */
-         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+         png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+         png_ptr->zowner = 0;
 
          /* This may be a truncated stream (missing or
           * damaged end code).  Treat that as a warning.
@@ -929,7 +904,8 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
          {
             /* Extra data. */
             png_warning(png_ptr, "Extra compressed data in IDAT");
-            png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+            png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
+            png_ptr->zowner = 0;
 
             /* Do no more processing; skip the unprocessed
              * input check below.
@@ -944,7 +920,7 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
 
       /* And check for the end of the stream. */
       if (ret == Z_STREAM_END)
-         png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+         png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
    }
 
    /* All the data should have been processed, if anything
@@ -956,7 +932,7 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
 }
 
 void /* PRIVATE */
-png_push_process_row(png_structp png_ptr)
+png_push_process_row(png_structrp png_ptr)
 {
    /* 1.5.6: row_info moved out of png_struct to a local here. */
    png_row_info row_info;
@@ -982,7 +958,7 @@ png_push_process_row(png_structp png_ptr)
     * it may not be in the future, so this was changed just to copy the
     * interlaced row count:
     */
-   png_memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
+   memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1);
 
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
    if (png_ptr->transformations)
@@ -1185,26 +1161,26 @@ png_push_process_row(png_structp png_ptr)
 }
 
 void /* PRIVATE */
-png_read_push_finish_row(png_structp png_ptr)
+png_read_push_finish_row(png_structrp png_ptr)
 {
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
-   static PNG_CONST png_byte FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+   static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
 
    /* Offset to next interlace block */
-   static PNG_CONST png_byte FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
 
    /* Start of interlace block in the y direction */
-   static PNG_CONST png_byte FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+   static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
 
    /* Offset to next interlace block in the y direction */
-   static PNG_CONST png_byte FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+   static PNG_CONST png_byte png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
 
    /* Height of interlace block.  This is not currently used - if you need
     * it, uncomment it here and in png.h
-   static PNG_CONST png_byte FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+   static PNG_CONST png_byte png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
    */
 #endif
 
@@ -1216,7 +1192,7 @@ png_read_push_finish_row(png_structp png_ptr)
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
-      png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
+      memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
 
       do
       {
@@ -1251,21 +1227,21 @@ png_read_push_finish_row(png_structp png_ptr)
 }
 
 void /* PRIVATE */
-png_push_have_info(png_structp png_ptr, png_infop info_ptr)
+png_push_have_info(png_structrp png_ptr, png_inforp info_ptr)
 {
    if (png_ptr->info_fn != NULL)
       (*(png_ptr->info_fn))(png_ptr, info_ptr);
 }
 
 void /* PRIVATE */
-png_push_have_end(png_structp png_ptr, png_infop info_ptr)
+png_push_have_end(png_structrp png_ptr, png_inforp info_ptr)
 {
    if (png_ptr->end_fn != NULL)
       (*(png_ptr->end_fn))(png_ptr, info_ptr);
 }
 
 void /* PRIVATE */
-png_push_have_row(png_structp png_ptr, png_bytep row)
+png_push_have_row(png_structrp png_ptr, png_bytep row)
 {
    if (png_ptr->row_fn != NULL)
       (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
@@ -1274,7 +1250,7 @@ png_push_have_row(png_structp png_ptr, png_bytep row)
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
 void PNGAPI
-png_progressive_combine_row (png_structp png_ptr, png_bytep old_row,
+png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
     png_const_bytep new_row)
 {
    if (png_ptr == NULL)
@@ -1290,7 +1266,7 @@ png_progressive_combine_row (png_structp png_ptr, png_bytep old_row,
 #endif /* PNG_READ_INTERLACING_SUPPORTED */
 
 void PNGAPI
-png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
+png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
     png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
     png_progressive_end_ptr end_fn)
 {
@@ -1305,7 +1281,7 @@ png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
 }
 
 png_voidp PNGAPI
-png_get_progressive_ptr(png_const_structp png_ptr)
+png_get_progressive_ptr(png_const_structrp png_ptr)
 {
    if (png_ptr == NULL)
       return (NULL);

pngrio.c

@@ -1,8 +1,8 @@
 
 /* pngrio.c - functions for data input
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.0 [February 14, 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.)
  *
@@ -29,7 +29,7 @@
  * to read more then 64K on a 16 bit machine.
  */
 void /* PRIVATE */
-png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length)
 {
    png_debug1(4, "reading %d bytes", (int)length);
 
@@ -46,7 +46,6 @@ png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
  * read_data function and use it at run time with png_set_read_fn(), rather
  * than changing the library.
  */
-#  ifndef USE_FAR_KEYWORD
 void PNGCBAPI
 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
@@ -58,68 +57,11 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
    /* fread() returns 0 on error, so it is OK to store this in a png_size_t
     * instead of an int, which is what fread() actually returns.
     */
-   check = fread(data, 1, length, (png_FILE_p)png_ptr->io_ptr);
+   check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
 
    if (check != length)
       png_error(png_ptr, "Read Error");
 }
-#  else
-/* This is the model-independent version. Since the standard I/O library
-   can't handle far buffers in the medium and small models, we have to copy
-   the data.
-*/
-
-#define NEAR_BUF_SIZE 1024
-#define MIN(a,b) (a <= b ? a : b)
-
-static void PNGCBAPI
-png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
-   png_size_t check;
-   png_byte *n_data;
-   png_FILE_p io_ptr;
-
-   if (png_ptr == NULL)
-      return;
-
-   /* Check if data really is near. If so, use usual code. */
-   n_data = (png_byte *)CVT_PTR_NOCHECK(data);
-   io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
-
-   if ((png_bytep)n_data == data)
-   {
-      check = fread(n_data, 1, length, io_ptr);
-   }
-
-   else
-   {
-      png_byte buf[NEAR_BUF_SIZE];
-      png_size_t read, remaining, err;
-      check = 0;
-      remaining = length;
-
-      do
-      {
-         read = MIN(NEAR_BUF_SIZE, remaining);
-         err = fread(buf, 1, read, io_ptr);
-         png_memcpy(data, buf, read); /* copy far buffer to near buffer */
-
-         if (err != read)
-            break;
-
-         else
-            check += err;
-
-         data += read;
-         remaining -= read;
-      }
-      while (remaining != 0);
-   }
-
-   if ((png_uint_32)check != (png_uint_32)length)
-      png_error(png_ptr, "read Error");
-}
-#  endif
 #endif
 
 /* This function allows the application to supply a new input function
@@ -142,7 +84,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
  *                be used.
  */
 void PNGAPI
-png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
+png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
    png_rw_ptr read_data_fn)
 {
    if (png_ptr == NULL)

pngrtran.c

@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.5.18 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
  * 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.)
@@ -22,7 +22,7 @@
 
 /* Set the action on getting a CRC error for an ancillary or critical chunk. */
 void PNGAPI
-png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
+png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
 {
    png_debug(1, "in png_set_crc_action");
 
@@ -88,16 +88,46 @@ png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
    }
 }
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+/* Is it OK to set a transformation now?  Only if png_start_read_image or
+ * png_read_update_info have not been called.  It is not necessary for the IHDR
+ * to have been read in all cases, the parameter allows for this check too.
+ */
+static int
+png_rtran_ok(png_structrp png_ptr, int need_IHDR)
+{
+   if (png_ptr != NULL)
+   {
+      if (png_ptr->flags & PNG_FLAG_ROW_INIT)
+         png_app_error(png_ptr,
+            "invalid after png_start_read_image or png_read_update_info");
+
+      else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0)
+         png_app_error(png_ptr, "invalid before the PNG header has been read");
+
+      else
+      {
+         /* Turn on failure to initialize correctly for all transforms. */
+         png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
+
+         return 1; /* Ok */
+      }
+   }
+
+   return 0; /* no png_error possible! */
+}
+#endif
+
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
 /* Handle alpha and tRNS via a background color */
 void PNGFAPI
-png_set_background_fixed(png_structp png_ptr,
+png_set_background_fixed(png_structrp png_ptr,
     png_const_color_16p background_color, int background_gamma_code,
     int need_expand, png_fixed_point background_gamma)
 {
    png_debug(1, "in png_set_background_fixed");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0) || background_color == NULL)
       return;
 
    if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
@@ -110,8 +140,7 @@ png_set_background_fixed(png_structp png_ptr,
    png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
    png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
 
-   png_memcpy(&(png_ptr->background), background_color,
-      png_sizeof(png_color_16));
+   png_ptr->background = *background_color;
    png_ptr->background_gamma = background_gamma;
    png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
    if (need_expand)
@@ -122,7 +151,7 @@ png_set_background_fixed(png_structp png_ptr,
 
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 void PNGAPI
-png_set_background(png_structp png_ptr,
+png_set_background(png_structrp png_ptr,
     png_const_color_16p background_color, int background_gamma_code,
     int need_expand, double background_gamma)
 {
@@ -138,11 +167,11 @@ png_set_background(png_structp png_ptr,
  */
 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
 void PNGAPI
-png_set_scale_16(png_structp png_ptr)
+png_set_scale_16(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_scale_16");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    png_ptr->transformations |= PNG_SCALE_16_TO_8;
@@ -152,11 +181,11 @@ png_set_scale_16(png_structp png_ptr)
 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
 /* Chop 16-bit depth files to 8-bit depth */
 void PNGAPI
-png_set_strip_16(png_structp png_ptr)
+png_set_strip_16(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_strip_16");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    png_ptr->transformations |= PNG_16_TO_8;
@@ -165,11 +194,11 @@ png_set_strip_16(png_structp png_ptr)
 
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
 void PNGAPI
-png_set_strip_alpha(png_structp png_ptr)
+png_set_strip_alpha(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_strip_alpha");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    png_ptr->transformations |= PNG_STRIP_ALPHA;
@@ -178,7 +207,7 @@ png_set_strip_alpha(png_structp png_ptr)
 
 #if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
 static png_fixed_point
-translate_gamma_flags(png_structp png_ptr, png_fixed_point output_gamma,
+translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma,
    int is_screen)
 {
    /* Check for flag values.  The main reason for having the old Mac value as a
@@ -217,7 +246,7 @@ translate_gamma_flags(png_structp png_ptr, png_fixed_point output_gamma,
 
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 static png_fixed_point
-convert_gamma_value(png_structp png_ptr, double output_gamma)
+convert_gamma_value(png_structrp png_ptr, double output_gamma)
 {
    /* The following silently ignores cases where fixed point (times 100,000)
     * gamma values are passed to the floating point API.  This is safe and it
@@ -242,7 +271,7 @@ convert_gamma_value(png_structp png_ptr, double output_gamma)
 
 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
 void PNGFAPI
-png_set_alpha_mode_fixed(png_structp png_ptr, int mode,
+png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
    png_fixed_point output_gamma)
 {
    int compose = 0;
@@ -250,7 +279,7 @@ png_set_alpha_mode_fixed(png_structp png_ptr, int mode,
 
    png_debug(1, "in png_set_alpha_mode");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
@@ -322,8 +351,11 @@ png_set_alpha_mode_fixed(png_structp png_ptr, int mode,
     * the side effect that the gamma in a second call to png_set_alpha_mode will
     * be ignored.)
     */
-   if (png_ptr->gamma == 0)
-      png_ptr->gamma = file_gamma;
+   if (png_ptr->colorspace.gamma == 0)
+   {
+      png_ptr->colorspace.gamma = file_gamma;
+      png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
+   }
 
    /* But always set the output gamma: */
    png_ptr->screen_gamma = output_gamma;
@@ -334,8 +366,8 @@ png_set_alpha_mode_fixed(png_structp png_ptr, int mode,
    if (compose)
    {
       /* And obtain alpha pre-multiplication by composing on black: */
-      png_memset(&png_ptr->background, 0, sizeof png_ptr->background);
-      png_ptr->background_gamma = png_ptr->gamma; /* just in case */
+      memset(&png_ptr->background, 0, (sizeof png_ptr->background));
+      png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */
       png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
       png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
 
@@ -345,14 +377,11 @@ png_set_alpha_mode_fixed(png_structp png_ptr, int mode,
 
       png_ptr->transformations |= PNG_COMPOSE;
    }
-
-   /* New API, make sure apps call the correct initializers: */
-   png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
 }
 
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 void PNGAPI
-png_set_alpha_mode(png_structp png_ptr, int mode, double output_gamma)
+png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
 {
    png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
       output_gamma));
@@ -372,21 +401,21 @@ png_set_alpha_mode(png_structp png_ptr, int mode, double output_gamma)
 
 typedef struct png_dsort_struct
 {
-   struct png_dsort_struct FAR * next;
+   struct png_dsort_struct * next;
    png_byte left;
    png_byte right;
 } png_dsort;
-typedef png_dsort FAR *       png_dsortp;
-typedef png_dsort FAR * FAR * png_dsortpp;
+typedef png_dsort *   png_dsortp;
+typedef png_dsort * * png_dsortpp;
 
 void PNGAPI
-png_set_quantize(png_structp png_ptr, png_colorp palette,
+png_set_quantize(png_structrp png_ptr, png_colorp palette,
     int num_palette, int maximum_colors, png_const_uint_16p histogram,
     int full_quantize)
 {
    png_debug(1, "in png_set_quantize");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    png_ptr->transformations |= PNG_QUANTIZE;
@@ -396,7 +425,7 @@ png_set_quantize(png_structp png_ptr, png_colorp palette,
       int i;
 
       png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
-          (png_uint_32)(num_palette * png_sizeof(png_byte)));
+          (png_uint_32)(num_palette * (sizeof (png_byte))));
       for (i = 0; i < num_palette; i++)
          png_ptr->quantize_index[i] = (png_byte)i;
    }
@@ -413,7 +442,7 @@ png_set_quantize(png_structp png_ptr, png_colorp palette,
 
          /* Initialize an array to sort colors */
          png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+             (png_uint_32)(num_palette * (sizeof (png_byte))));
 
          /* Initialize the quantize_sort array */
          for (i = 0; i < num_palette; i++)
@@ -547,9 +576,9 @@ png_set_quantize(png_structp png_ptr, png_colorp palette,
 
          /* Initialize palette index arrays */
          png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+             (png_uint_32)(num_palette * (sizeof (png_byte))));
          png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
-             (png_uint_32)(num_palette * png_sizeof(png_byte)));
+             (png_uint_32)(num_palette * (sizeof (png_byte))));
 
          /* Initialize the sort array */
          for (i = 0; i < num_palette; i++)
@@ -559,7 +588,7 @@ png_set_quantize(png_structp png_ptr, png_colorp palette,
          }
 
          hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
-             png_sizeof(png_dsortp)));
+             (sizeof (png_dsortp))));
 
          num_new_palette = num_palette;
 
@@ -589,7 +618,7 @@ png_set_quantize(png_structp png_ptr, png_colorp palette,
                   {
 
                      t = (png_dsortp)png_malloc_warn(png_ptr,
-                         (png_uint_32)(png_sizeof(png_dsort)));
+                         (png_uint_32)(sizeof (png_dsort)));
 
                      if (t == NULL)
                          break;
@@ -714,12 +743,12 @@ png_set_quantize(png_structp png_ptr, png_colorp palette,
       png_size_t num_entries = ((png_size_t)1 << total_bits);
 
       png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
-          (png_uint_32)(num_entries * png_sizeof(png_byte)));
+          (png_uint_32)(num_entries * (sizeof (png_byte))));
 
       distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
-          png_sizeof(png_byte)));
+          (sizeof (png_byte))));
 
-      png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
+      memset(distance, 0xff, num_entries * (sizeof (png_byte)));
 
       for (i = 0; i < num_palette; i++)
       {
@@ -768,19 +797,18 @@ png_set_quantize(png_structp png_ptr, png_colorp palette,
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
 void PNGFAPI
-png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma,
+png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
    png_fixed_point file_gamma)
 {
    png_debug(1, "in png_set_gamma_fixed");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    /* New in libpng-1.5.4 - reserve particular negative values as flags. */
    scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/);
    file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/);
 
-#if PNG_LIBPNG_VER >= 10600
    /* Checking the gamma values for being >0 was added in 1.5.4 along with the
     * premultiplied alpha support; this actually hides an undocumented feature
     * of the previous implementation which allowed gamma processing to be
@@ -789,26 +817,27 @@ png_set_gamma_fixed(png_structp png_ptr, png_fixed_point scrn_gamma,
     * accept '0' for the gamma value it takes, because it isn't always used.
     *
     * Since this is an API change (albeit a very minor one that removes an
-    * undocumented API feature) it will not be made until libpng-1.6.0.
+    * undocumented API feature) the following checks were only enabled in
+    * libpng-1.6.0.
     */
    if (file_gamma <= 0)
       png_error(png_ptr, "invalid file gamma in png_set_gamma");
 
    if (scrn_gamma <= 0)
       png_error(png_ptr, "invalid screen gamma in png_set_gamma");
-#endif
 
    /* Set the gamma values unconditionally - this overrides the value in the PNG
     * file if a gAMA chunk was present.  png_set_alpha_mode provides a
     * different, easier, way to default the file gamma.
     */
-   png_ptr->gamma = file_gamma;
+   png_ptr->colorspace.gamma = file_gamma;
+   png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
    png_ptr->screen_gamma = scrn_gamma;
 }
 
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 void PNGAPI
-png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
+png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
 {
    png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
       convert_gamma_value(png_ptr, file_gamma));
@@ -822,15 +851,14 @@ png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
  * to alpha channels.
  */
 void PNGAPI
-png_set_expand(png_structp png_ptr)
+png_set_expand(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_expand");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
 }
 
 /* GRR 19990627:  the following three functions currently are identical
@@ -853,40 +881,38 @@ png_set_expand(png_structp png_ptr)
 
 /* Expand paletted images to RGB. */
 void PNGAPI
-png_set_palette_to_rgb(png_structp png_ptr)
+png_set_palette_to_rgb(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_palette_to_rgb");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
 }
 
 /* Expand grayscale images of less than 8-bit depth to 8 bits. */
 void PNGAPI
-png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
+png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    png_ptr->transformations |= PNG_EXPAND;
-   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
 }
 
-
-
 /* Expand tRNS chunks to alpha channels. */
 void PNGAPI
-png_set_tRNS_to_alpha(png_structp png_ptr)
+png_set_tRNS_to_alpha(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_tRNS_to_alpha");
 
+   if (!png_rtran_ok(png_ptr, 0))
+      return;
+
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
 }
 #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
 
@@ -895,45 +921,42 @@ png_set_tRNS_to_alpha(png_structp png_ptr)
  * it may not work correctly.)
  */
 void PNGAPI
-png_set_expand_16(png_structp png_ptr)
+png_set_expand_16(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_expand_16");
 
-   if (png_ptr == NULL)
+   if (!png_rtran_ok(png_ptr, 0))
       return;
 
    png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
-   png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-
-   /* New API, make sure apps call the correct initializers: */
-   png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
 }
 #endif
 
 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
 void PNGAPI
-png_set_gray_to_rgb(png_structp png_ptr)
+png_set_gray_to_rgb(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_gray_to_rgb");
 
-   if (png_ptr != NULL)
-   {
-      /* Because rgb must be 8 bits or more: */
-      png_set_expand_gray_1_2_4_to_8(png_ptr);
-      png_ptr->transformations |= PNG_GRAY_TO_RGB;
-      png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-   }
+   if (!png_rtran_ok(png_ptr, 0))
+      return;
+
+   /* Because rgb must be 8 bits or more: */
+   png_set_expand_gray_1_2_4_to_8(png_ptr);
+   png_ptr->transformations |= PNG_GRAY_TO_RGB;
 }
 #endif
 
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
 void PNGFAPI
-png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
+png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
     png_fixed_point red, png_fixed_point green)
 {
    png_debug(1, "in png_set_rgb_to_gray");
 
-   if (png_ptr == NULL)
+   /* Need the IHDR here because of the check on color_type below. */
+   /* TODO: fix this */
+   if (!png_rtran_ok(png_ptr, 1))
       return;
 
    switch(error_action)
@@ -954,15 +977,19 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
          png_error(png_ptr, "invalid error action to rgb_to_gray");
          break;
    }
+
    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
 #ifdef PNG_READ_EXPAND_SUPPORTED
       png_ptr->transformations |= PNG_EXPAND;
 #else
    {
-      png_warning(png_ptr,
+      /* Make this an error in 1.6 because otherwise the application may assume
+       * that it just worked and get a memory overwrite.
+       */
+      png_error(png_ptr,
         "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
 
-      png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
+      /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */
    }
 #endif
    {
@@ -986,7 +1013,7 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
       else
       {
          if (red >= 0 && green >= 0)
-            png_warning(png_ptr,
+            png_app_warning(png_ptr,
                "ignoring out of range rgb_to_gray coefficients");
 
          /* Use the defaults, from the cHRM chunk if set, else the historical
@@ -1012,31 +1039,25 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
  */
 
 void PNGAPI
-png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
+png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red,
    double green)
 {
-   if (png_ptr == NULL)
-      return;
-
    png_set_rgb_to_gray_fixed(png_ptr, error_action,
       png_fixed(png_ptr, red, "rgb to gray red coefficient"),
       png_fixed(png_ptr, green, "rgb to gray green coefficient"));
 }
 #endif /* FLOATING POINT */
 
-#endif
+#endif /* RGB_TO_GRAY */
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
 void PNGAPI
-png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
+png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
     read_user_transform_fn)
 {
    png_debug(1, "in png_set_read_user_transform_fn");
 
-   if (png_ptr == NULL)
-      return;
-
 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
    png_ptr->transformations |= PNG_USER_TRANSFORM;
    png_ptr->read_user_transform_fn = read_user_transform_fn;
@@ -1076,7 +1097,7 @@ png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
  * extracted from 'png_init_read_transformations'.
  */
 static void /* PRIVATE */
-png_init_palette_transformations(png_structp png_ptr)
+png_init_palette_transformations(png_structrp png_ptr)
 {
    /* Called to handle the (input) palette case.  In png_do_read_transformations
     * the first step is to expand the palette if requested, so this code must
@@ -1165,7 +1186,7 @@ png_init_palette_transformations(png_structp png_ptr)
 }
 
 static void /* PRIVATE */
-png_init_rgb_transformations(png_structp png_ptr)
+png_init_rgb_transformations(png_structrp png_ptr)
 {
    /* Added to libpng-1.5.4: check the color type to determine whether there
     * is any alpha or transparency in the image and simply cancel the
@@ -1229,7 +1250,7 @@ png_init_rgb_transformations(png_structp png_ptr)
             default:
 
             case 8:
-               /* FALL THROUGH (already 8 bits) */
+               /* FALL THROUGH (Already 8 bits) */
 
             case 16:
                /* Already a full 16 bits */
@@ -1250,7 +1271,7 @@ png_init_rgb_transformations(png_structp png_ptr)
 }
 
 void /* PRIVATE */
-png_init_read_transformations(png_structp png_ptr)
+png_init_read_transformations(png_structrp png_ptr)
 {
    png_debug(1, "in png_init_read_transformations");
 
@@ -1275,17 +1296,17 @@ png_init_read_transformations(png_structp png_ptr)
        */
       int gamma_correction = 0;
 
-      if (png_ptr->gamma != 0) /* has been set */
+      if (png_ptr->colorspace.gamma != 0) /* has been set */
       {
          if (png_ptr->screen_gamma != 0) /* screen set too */
-            gamma_correction = png_gamma_threshold(png_ptr->gamma,
+            gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma,
                png_ptr->screen_gamma);
 
          else
             /* Assume the output matches the input; a long time default behavior
              * of libpng, although the standard has nothing to say about this.
              */
-            png_ptr->screen_gamma = png_reciprocal(png_ptr->gamma);
+            png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma);
       }
 
       else if (png_ptr->screen_gamma != 0)
@@ -1294,7 +1315,7 @@ png_init_read_transformations(png_structp png_ptr)
           * png_set_alpha_mode (even if the alpha handling mode isn't required
           * or isn't changed from the default.)
           */
-         png_ptr->gamma = png_reciprocal(png_ptr->screen_gamma);
+         png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma);
 
       else /* neither are set */
          /* Just in case the following prevents any processing - file and screen
@@ -1302,7 +1323,10 @@ png_init_read_transformations(png_structp png_ptr)
           * third gamma value other than png_set_background with 'UNIQUE', and,
           * prior to 1.5.4
           */
-         png_ptr->screen_gamma = png_ptr->gamma = PNG_FP_1;
+         png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1;
+
+      /* We have a gamma value now. */
+      png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
 
       /* Now turn the gamma transformation on or off as appropriate.  Notice
        * that PNG_GAMMA just refers to the file->screen correction.  Alpha
@@ -1384,9 +1408,16 @@ png_init_read_transformations(png_structp png_ptr)
    }
 #endif
 
-#if defined(PNG_READ_EXPAND_SUPPORTED) && \
-   defined(PNG_READ_BACKGROUND_SUPPORTED) && \
-   defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+   /* Make sure the coefficients for the rgb to gray conversion are set
+    * appropriately.
+    */
+   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+      png_colorspace_set_rgb_coefficients(png_ptr);
+#endif
+
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
    /* Detect gray background and attempt to enable optimization for
     * gray --> RGB case.
     *
@@ -1428,7 +1459,8 @@ png_init_read_transformations(png_structp png_ptr)
          }
       }
    }
-#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED (etc) */
+#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
+#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */
 
    /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
     * can be performed directly on the palette, and some (such as rgb to gray)
@@ -1464,7 +1496,7 @@ png_init_read_transformations(png_structp png_ptr)
        * NOTE: this discards the low 16 bits of the user supplied background
        * color, but until expand_16 works properly there is no choice!
        */
-#     define CHOP(x) (x)=((png_uint_16)(((png_uint_32)(x)*255+32895) >> 16))
+#     define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x))
       CHOP(png_ptr->background.red);
       CHOP(png_ptr->background.green);
       CHOP(png_ptr->background.blue);
@@ -1524,10 +1556,10 @@ png_init_read_transformations(png_structp png_ptr)
     */
    if ((png_ptr->transformations & PNG_GAMMA)
       || ((png_ptr->transformations & PNG_RGB_TO_GRAY)
-         && (png_gamma_significant(png_ptr->gamma) ||
+         && (png_gamma_significant(png_ptr->colorspace.gamma) ||
             png_gamma_significant(png_ptr->screen_gamma)))
       || ((png_ptr->transformations & PNG_COMPOSE)
-         && (png_gamma_significant(png_ptr->gamma)
+         && (png_gamma_significant(png_ptr->colorspace.gamma)
             || png_gamma_significant(png_ptr->screen_gamma)
 #  ifdef PNG_READ_BACKGROUND_SUPPORTED
             || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE
@@ -1584,8 +1616,8 @@ png_init_read_transformations(png_structp png_ptr)
                      break;
 
                   case PNG_BACKGROUND_GAMMA_FILE:
-                     g = png_reciprocal(png_ptr->gamma);
-                     gs = png_reciprocal2(png_ptr->gamma,
+                     g = png_reciprocal(png_ptr->colorspace.gamma);
+                     gs = png_reciprocal2(png_ptr->colorspace.gamma,
                         png_ptr->screen_gamma);
                      break;
 
@@ -1693,8 +1725,9 @@ png_init_read_transformations(png_structp png_ptr)
                   break;
 
                case PNG_BACKGROUND_GAMMA_FILE:
-                  g = png_reciprocal(png_ptr->gamma);
-                  gs = png_reciprocal2(png_ptr->gamma, png_ptr->screen_gamma);
+                  g = png_reciprocal(png_ptr->colorspace.gamma);
+                  gs = png_reciprocal2(png_ptr->colorspace.gamma,
+                     png_ptr->screen_gamma);
                   break;
 
                case PNG_BACKGROUND_GAMMA_UNIQUE:
@@ -1851,31 +1884,34 @@ png_init_read_transformations(png_structp png_ptr)
        * the number of significant bits is 0 then no shift is done (this is an
        * error condition which is silently ignored.)
        */
-      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
-      {
-         int component = png_ptr->palette[i].red;
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].red;
 
-         component >>= shift;
-         png_ptr->palette[i].red = (png_byte)component;
-      }
+            component >>= shift;
+            png_ptr->palette[i].red = (png_byte)component;
+         }
 
       shift = 8 - png_ptr->sig_bit.green;
-      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
-      {
-         int component = png_ptr->palette[i].green;
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].green;
 
-         component >>= shift;
-         png_ptr->palette[i].green = (png_byte)component;
-      }
+            component >>= shift;
+            png_ptr->palette[i].green = (png_byte)component;
+         }
 
       shift = 8 - png_ptr->sig_bit.blue;
-      if (shift > 0 && shift < 8) for (i=0; i<istop; ++i)
-      {
-         int component = png_ptr->palette[i].blue;
+      if (shift > 0 && shift < 8)
+         for (i=0; i<istop; ++i)
+         {
+            int component = png_ptr->palette[i].blue;
 
-         component >>= shift;
-         png_ptr->palette[i].blue = (png_byte)component;
-      }
+            component >>= shift;
+            png_ptr->palette[i].blue = (png_byte)component;
+         }
    }
 #endif  /* PNG_READ_SHIFT_SUPPORTED */
 }
@@ -1885,7 +1921,7 @@ png_init_read_transformations(png_structp png_ptr)
  * assuming the transformations result in valid PNG data.
  */
 void /* PRIVATE */
-png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
+png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
 {
    png_debug(1, "in png_read_transform_info");
 
@@ -1906,6 +1942,9 @@ png_read_transform_info(png_structp png_ptr, png_infop 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
       {
@@ -1936,8 +1975,12 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
     * however it seems that the code in png_init_read_transformations, which has
     * been called before this from png_read_update_info->png_read_start_row
     * sometimes does the gamma transform and cancels the flag.
+    *
+    * TODO: this looks wrong; the info_ptr should end up with a gamma equal to
+    * the screen_gamma value.  The following probably results in weirdness if
+    * the info_ptr is used by the app after the rows have been read.
     */
-   info_ptr->gamma = png_ptr->gamma;
+   info_ptr->colorspace.gamma = png_ptr->colorspace.gamma;
 #endif
 
    if (info_ptr->bit_depth == 16)
@@ -2085,7 +2128,7 @@ defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
  * decide how it fits in with the other transformations here.
  */
 void /* PRIVATE */
-png_do_read_transformations(png_structp png_ptr, png_row_infop row_info)
+png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
 {
    png_debug(1, "in png_do_read_transformations");
 
@@ -2100,8 +2143,9 @@ png_do_read_transformations(png_structp png_ptr, png_row_infop row_info)
 
    /* The following is debugging; prior to 1.5.4 the code was never compiled in;
     * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
-    * PNG_WARN_UNINITIALIZED_ROW removed.  In 1.5 the new flag is set only for
-    * selected new APIs to ensure that there is no API change.
+    * PNG_WARN_UNINITIALIZED_ROW removed.  In 1.6 the new flag is set only for
+    * all transformations, however in practice the ROW_INIT always gets done on
+    * demand, if necessary.
     */
    if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
       !(png_ptr->flags & PNG_FLAG_ROW_INIT))
@@ -3232,7 +3276,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
  *  to that used above.
  */
 int /* PRIVATE */
-png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
+png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
 
 {
    int rgb_error = 0;
@@ -3251,7 +3295,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
 
       if (row_info->bit_depth == 8)
       {
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
          /* Notice that gamma to/from 1 are not necessarily inverses (if
           * there is an overall gamma correction).  Prior to 1.5.5 this code
           * checked the linearized values for equality; this doesn't match
@@ -3328,7 +3372,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
 
       else /* RGB bit_depth == 16 */
       {
-#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
          if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
          {
             png_bytep sp = row;
@@ -3492,7 +3536,7 @@ png_build_grayscale_palette(int bit_depth, png_colorp palette)
  * at a gamma of 1.0.  Paletted files have already been taken care of.
  */
 void /* PRIVATE */
-png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
+png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 {
 #ifdef PNG_READ_GAMMA_SUPPORTED
    png_const_bytep gamma_table = png_ptr->gamma_table;
@@ -3502,12 +3546,12 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
    png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
    png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
    int gamma_shift = png_ptr->gamma_shift;
+   int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
 #endif
 
    png_bytep sp;
    png_uint_32 i;
    png_uint_32 row_width = row_info->width;
-   int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
    int shift;
 
    png_debug(1, "in png_do_compose");
@@ -3528,8 +3572,9 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
                      if ((png_uint_16)((*sp >> shift) & 0x01)
                         == png_ptr->trans_color.gray)
                      {
-                        *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
-                        *sp |= (png_byte)(png_ptr->background.gray << shift);
+                        unsigned int tmp = *sp & (0x7f7f >> (7 - shift));
+                        tmp |= png_ptr->background.gray << shift;
+                        *sp = (png_byte)(tmp & 0xff);
                      }
 
                      if (!shift)
@@ -3556,17 +3601,19 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
                         if ((png_uint_16)((*sp >> shift) & 0x03)
                             == png_ptr->trans_color.gray)
                         {
-                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
-                           *sp |= (png_byte)(png_ptr->background.gray << shift);
+                           unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+                           tmp |= png_ptr->background.gray << shift;
+                           *sp = (png_byte)(tmp & 0xff);
                         }
 
                         else
                         {
-                           png_byte p = (png_byte)((*sp >> shift) & 0x03);
-                           png_byte g = (png_byte)((gamma_table [p | (p << 2) |
-                               (p << 4) | (p << 6)] >> 6) & 0x03);
-                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
-                           *sp |= (png_byte)(g << shift);
+                           unsigned int p = (*sp >> shift) & 0x03;
+                           unsigned int g = (gamma_table [p | (p << 2) |
+                               (p << 4) | (p << 6)] >> 6) & 0x03;
+                           unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+                           tmp |= g << shift;
+                           *sp = (png_byte)(tmp & 0xff);
                         }
 
                         if (!shift)
@@ -3590,8 +3637,9 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
                         if ((png_uint_16)((*sp >> shift) & 0x03)
                             == png_ptr->trans_color.gray)
                         {
-                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
-                           *sp |= (png_byte)(png_ptr->background.gray << shift);
+                           unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
+                           tmp |= png_ptr->background.gray << shift;
+                           *sp = (png_byte)(tmp & 0xff);
                         }
 
                         if (!shift)
@@ -3619,17 +3667,19 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
                         if ((png_uint_16)((*sp >> shift) & 0x0f)
                             == png_ptr->trans_color.gray)
                         {
-                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
-                           *sp |= (png_byte)(png_ptr->background.gray << shift);
+                           unsigned int tmp = *sp & (0xf0f >> (4 - shift));
+                           tmp |= png_ptr->background.gray << shift;
+                           *sp = (png_byte)(tmp & 0xff);
                         }
 
                         else
                         {
-                           png_byte p = (png_byte)((*sp >> shift) & 0x0f);
-                           png_byte g = (png_byte)((gamma_table[p |
-                               (p << 4)] >> 4) & 0x0f);
-                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
-                           *sp |= (png_byte)(g << shift);
+                           unsigned int p = (*sp >> shift) & 0x0f;
+                           unsigned int g = (gamma_table[p | (p << 4)] >> 4) &
+                              0x0f;
+                           unsigned int tmp = *sp & (0xf0f >> (4 - shift));
+                           tmp |= g << shift;
+                           *sp = (png_byte)(tmp & 0xff);
                         }
 
                         if (!shift)
@@ -3653,8 +3703,9 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
                         if ((png_uint_16)((*sp >> shift) & 0x0f)
                             == png_ptr->trans_color.gray)
                         {
-                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
-                           *sp |= (png_byte)(png_ptr->background.gray << shift);
+                           unsigned int tmp = *sp & (0xf0f >> (4 - shift));
+                           tmp |= png_ptr->background.gray << shift;
+                           *sp = (png_byte)(tmp & 0xff);
                         }
 
                         if (!shift)
@@ -4134,16 +4185,16 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
                         v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
                         png_composite_16(w, v, a, png_ptr->background_1.red);
                         if (!optimize)
-                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)]
-                               [w >> 8];
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
+                                8];
                         *sp = (png_byte)((w >> 8) & 0xff);
                         *(sp + 1) = (png_byte)(w & 0xff);
 
                         v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
                         png_composite_16(w, v, a, png_ptr->background_1.green);
                         if (!optimize)
-                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)]
-                               [w >> 8];
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
+                                8];
 
                         *(sp + 2) = (png_byte)((w >> 8) & 0xff);
                         *(sp + 3) = (png_byte)(w & 0xff);
@@ -4151,8 +4202,8 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
                         v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
                         png_composite_16(w, v, a, png_ptr->background_1.blue);
                         if (!optimize)
-                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)]
-                               [w >> 8];
+                           w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
+                                8];
 
                         *(sp + 4) = (png_byte)((w >> 8) & 0xff);
                         *(sp + 5) = (png_byte)(w & 0xff);
@@ -4225,7 +4276,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr)
  * build_gamma_table().
  */
 void /* PRIVATE */
-png_do_gamma(png_row_infop row_info, png_bytep row, png_structp png_ptr)
+png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 {
    png_const_bytep gamma_table = png_ptr->gamma_table;
    png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
@@ -4426,7 +4477,7 @@ png_do_gamma(png_row_infop row_info, png_bytep row, png_structp png_ptr)
  * from_1 tables.
  */
 void /* PRIVATE */
-png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structp png_ptr)
+png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 {
    png_uint_32 row_width = row_info->width;
 
@@ -4658,7 +4709,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
    {
       if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
       {
-         png_uint_16 gray = (png_uint_16)(trans_color ? trans_color->gray : 0);
+         unsigned int gray = trans_color ? trans_color->gray : 0;
 
          if (row_info->bit_depth < 8)
          {
@@ -4666,7 +4717,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
             {
                case 1:
                {
-                  gray = (png_uint_16)((gray & 0x01) * 0xff);
+                  gray = (gray & 0x01) * 0xff;
                   sp = row + (png_size_t)((row_width - 1) >> 3);
                   dp = row + (png_size_t)row_width - 1;
                   shift = 7 - (int)((row_width + 7) & 0x07);
@@ -4694,7 +4745,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
 
                case 2:
                {
-                  gray = (png_uint_16)((gray & 0x03) * 0x55);
+                  gray = (gray & 0x03) * 0x55;
                   sp = row + (png_size_t)((row_width - 1) >> 2);
                   dp = row + (png_size_t)row_width - 1;
                   shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
@@ -4719,7 +4770,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
 
                case 4:
                {
-                  gray = (png_uint_16)((gray & 0x0f) * 0x11);
+                  gray = (gray & 0x0f) * 0x11;
                   sp = row + (png_size_t)((row_width - 1) >> 1);
                   dp = row + (png_size_t)row_width - 1;
                   shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
@@ -4754,9 +4805,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
          {
             if (row_info->bit_depth == 8)
             {
-               /* NOTE: prior to libpng 1.5.14 this cleared out the top bits of
-                * 'gray', however if those are set it is an error.
-                */
+               gray = gray & 0xff;
                sp = row + (png_size_t)row_width - 1;
                dp = row + (png_size_t)(row_width << 1) - 1;
 
@@ -4774,8 +4823,8 @@ png_do_expand(png_row_infop row_info, png_bytep row,
 
             else if (row_info->bit_depth == 16)
             {
-               png_byte gray_high = (png_byte)((gray >> 8) & 0xff);
-               png_byte gray_low = (png_byte)(gray & 0xff);
+               unsigned int gray_high = (gray >> 8) & 0xff;
+               unsigned int gray_low = gray & 0xff;
                sp = row + row_info->rowbytes - 1;
                dp = row + (row_info->rowbytes << 1) - 1;
                for (i = 0; i < row_width; i++)

pngstruct.h

@@ -5,7 +5,7 @@
  * (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 1.5.15 [March 28, 2013]
+ * Last changed in libpng 1.6.1 [March 28, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -24,13 +24,130 @@
  * 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
+
+/* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
+ * can handle at once.  This type need be no larger than 16 bits (so maximum of
+ * 65535), this define allows us to discover how big it is, but limited by the
+ * maximuum for png_size_t.  The value can be overriden in a library build
+ * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
+ * lower value (e.g. 255 works).  A lower value may help memory usage (slightly)
+ * and may even improve performance on some systems (and degrade it on others.)
+ */
+#ifndef ZLIB_IO_MAX
+#  define ZLIB_IO_MAX ((uInt)-1)
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+/* The type of a compression buffer list used by the write code. */
+typedef struct png_compression_buffer
+{
+   struct png_compression_buffer *next;
+   png_byte                       output[1]; /* actually zbuf_size */
+} png_compression_buffer, *png_compression_bufferp;
+
+#define PNG_COMPRESSION_BUFFER_SIZE(pp)\
+   (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
+#endif
+
+/* Colorspace support; structures used in png_struct, png_info and in internal
+ * functions to hold and communicate information about the color space.
+ *
+ * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
+ * colorspace corrections, otherwise all the colorspace information can be
+ * skipped and the size of libpng can be reduced (significantly) by compiling
+ * out the colorspace support.
+ */
+#ifdef PNG_COLORSPACE_SUPPORTED
+/* The chromaticities of the red, green and blue colorants and the chromaticity
+ * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
+ */
+typedef struct png_xy
+{
+   png_fixed_point redx, redy;
+   png_fixed_point greenx, greeny;
+   png_fixed_point bluex, bluey;
+   png_fixed_point whitex, whitey;
+} png_xy;
+
+/* The same data as above but encoded as CIE XYZ values.  When this data comes
+ * from chromaticities the sum of the Y values is assumed to be 1.0
+ */
+typedef struct png_XYZ
+{
+   png_fixed_point red_X, red_Y, red_Z;
+   png_fixed_point green_X, green_Y, green_Z;
+   png_fixed_point blue_X, blue_Y, blue_Z;
+} png_XYZ;
+#endif /* COLORSPACE */
+
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+/* A colorspace is all the above plus, potentially, profile information,
+ * however at present libpng does not use the profile internally so it is only
+ * stored in the png_info struct (if iCCP is supported.)  The rendering intent
+ * is retained here and is checked.
+ *
+ * The file gamma encoding information is also stored here and gamma correction
+ * is done by libpng, whereas color correction must currently be done by the
+ * application.
+ */
+typedef struct png_colorspace
+{
+#ifdef PNG_GAMMA_SUPPORTED
+   png_fixed_point gamma;        /* File gamma */
+#endif
+
+#ifdef PNG_COLORSPACE_SUPPORTED
+   png_xy      end_points_xy;    /* End points as chromaticities */
+   png_XYZ     end_points_XYZ;   /* End points as CIE XYZ colorant values */
+   png_uint_16 rendering_intent; /* Rendering intent of a profile */
+#endif
+
+   /* Flags are always defined to simplify the code. */
+   png_uint_16 flags;            /* As defined below */
+} png_colorspace, * PNG_RESTRICT png_colorspacerp;
+
+typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
+
+/* General flags for the 'flags' field */
+#define PNG_COLORSPACE_HAVE_GAMMA           0x0001
+#define PNG_COLORSPACE_HAVE_ENDPOINTS       0x0002
+#define PNG_COLORSPACE_HAVE_INTENT          0x0004
+#define PNG_COLORSPACE_FROM_gAMA            0x0008
+#define PNG_COLORSPACE_FROM_cHRM            0x0010
+#define PNG_COLORSPACE_FROM_sRGB            0x0020
+#define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
+#define PNG_COLORSPACE_MATCHES_sRGB         0x0080 /* exact match on profile */
+#define PNG_COLORSPACE_INVALID              0x8000
+#define PNG_COLORSPACE_CANCEL(flags)        (0xffff ^ (flags))
+#endif /* COLORSPACE || GAMMA */
 
 struct png_struct_def
 {
 #ifdef PNG_SETJMP_SUPPORTED
-   jmp_buf longjmp_buffer;    /* used in png_error */
+   jmp_buf jmp_buf_local;     /* New name in 1.6.0 for jmp_buf in png_struct */
    png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
+   jmp_buf *jmp_buf_ptr;      /* passed to longjmp_fn */
+   size_t jmp_buf_size;       /* size of the above, if allocated */
 #endif
    png_error_ptr error_fn;    /* function for printing errors and aborting */
 #ifdef PNG_WARNINGS_SUPPORTED
@@ -63,22 +180,12 @@ struct png_struct_def
    png_uint_32 flags;         /* flags indicating various things to libpng */
    png_uint_32 transformations; /* which transformations to perform */
 
-   z_stream zstream;          /* pointer to decompression structure (below) */
-   png_bytep zbuf;            /* buffer for zlib */
-   uInt zbuf_size;            /* size of zbuf (typically 65536) */
+   png_uint_32 zowner;        /* ID (chunk type) of zstream owner, 0 if none */
+   z_stream    zstream;       /* decompression structure */
+
 #ifdef PNG_WRITE_SUPPORTED
-
-/* Added in 1.5.4: state to keep track of whether the zstream has been
- * initialized and if so whether it is for IDAT or some other chunk.
- */
-#define PNG_ZLIB_UNINITIALIZED 0
-#define PNG_ZLIB_FOR_IDAT      1
-#define PNG_ZLIB_FOR_TEXT      2 /* anything other than IDAT */
-#define PNG_ZLIB_USE_MASK      3 /* bottom two bits */
-#define PNG_ZLIB_IN_USE        4 /* a flag value */
-
-   png_uint_32 zlib_state;       /* State of zlib initialization */
-/* End of material added at libpng 1.5.4 */
+   png_compression_bufferp zbuffer_list; /* Created on demand during write */
+   uInt                    zbuffer_size; /* size of the actual buffer */
 
    int zlib_level;            /* holds zlib compression level */
    int zlib_method;           /* holds zlib compression method */
@@ -87,8 +194,7 @@ struct png_struct_def
    int zlib_strategy;         /* holds zlib compression strategy */
 #endif
 /* Added at libpng 1.5.4 */
-#if defined(PNG_WRITE_COMPRESSED_TEXT_SUPPORTED) || \
-    defined(PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED)
+#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
    int zlib_text_level;            /* holds zlib compression level */
    int zlib_text_method;           /* holds zlib compression method */
    int zlib_text_window_bits;      /* holds zlib compression window bits */
@@ -96,6 +202,14 @@ struct png_struct_def
    int zlib_text_strategy;         /* holds zlib compression strategy */
 #endif
 /* End of material added at libpng 1.5.4 */
+/* Added at libpng 1.6.0 */
+#ifdef PNG_WRITE_SUPPORTED
+   int zlib_set_level;        /* Actual values set into the zstream on write */
+   int zlib_set_method;
+   int zlib_set_window_bits;
+   int zlib_set_mem_level;
+   int zlib_set_strategy;
+#endif
 
    png_uint_32 width;         /* width of image in pixels */
    png_uint_32 height;        /* height of image in pixels */
@@ -111,10 +225,12 @@ struct png_struct_def
    png_bytep row_buf;         /* buffer to save current (unfiltered) row.
                                * This is a pointer into big_row_buf
                                */
+#ifdef PNG_WRITE_SUPPORTED
    png_bytep sub_row;         /* buffer to save "sub" row when filtering */
    png_bytep up_row;          /* buffer to save "up" row when filtering */
    png_bytep avg_row;         /* buffer to save "avg" row when filtering */
    png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
+#endif
    png_size_t info_rowbytes;  /* Added in 1.5.4: cache of updated row bytes */
 
    png_uint_32 idat_size;     /* current IDAT size for read */
@@ -138,15 +254,14 @@ struct png_struct_def
    png_byte usr_bit_depth;    /* bit depth of users row: write only */
    png_byte pixel_depth;      /* number of bits per pixel */
    png_byte channels;         /* number of channels in file */
+#ifdef PNG_WRITE_SUPPORTED
    png_byte usr_channels;     /* channels at start of write: write only */
+#endif
    png_byte sig_bytes;        /* magic bytes read/written from start of file */
    png_byte maximum_pixel_depth;
                               /* pixel depth used for the row buffers */
    png_byte transformed_pixel_depth;
                               /* pixel depth after read/write transforms */
-   png_byte io_chunk_string[5];
-                              /* string name of chunk */
-
 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
    png_uint_16 filler;           /* filler bytes for pixel expansion */
 #endif
@@ -169,7 +284,6 @@ struct png_struct_def
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
    int gamma_shift;      /* number of "insignificant" bits in 16-bit gamma */
-   png_fixed_point gamma;        /* file gamma value */
    png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
 
    png_bytep gamma_table;     /* gamma table for 8-bit depth files */
@@ -233,10 +347,6 @@ struct png_struct_def
    png_bytep quantize_index; /* index translation for palette files */
 #endif
 
-#if defined(PNG_READ_QUANTIZE_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
-   png_uint_16p hist;                /* histogram */
-#endif
-
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
    png_byte heuristic_method;        /* heuristic for row filter selection */
    png_byte num_prev_filters;        /* number of weights for previous rows */
@@ -247,10 +357,17 @@ struct png_struct_def
    png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
 #endif
 
+   /* Options */
+#ifdef PNG_SET_OPTION_SUPPORTED
+   png_byte options;           /* On/off state (up to 4 options) */
+#endif
+
+#if PNG_LIBPNG_VER < 10700
+/* To do: remove this from libpng-1.7 */
 #ifdef PNG_TIME_RFC1123_SUPPORTED
-   /* This is going to be unused in libpng16 and removed from libpng17 */
    char time_buffer[29]; /* String to hold RFC 1123 time text */
 #endif
+#endif
 
 /* New members added in libpng-1.0.6 */
 
@@ -258,17 +375,16 @@ struct png_struct_def
 
 #ifdef PNG_USER_CHUNKS_SUPPORTED
    png_voidp user_chunk_ptr;
+#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
    png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
 #endif
-
-#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-   int num_chunk_list;
-   png_bytep chunk_list;
 #endif
 
-#ifdef PNG_READ_sRGB_SUPPORTED
-   /* Added in 1.5.5 to record an sRGB chunk in the png. */
-   png_byte is_sRGB;
+#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
+   int          unknown_default; /* As PNG_HANDLE_* */
+   unsigned int num_chunk_list;  /* Number of entries in the list */
+   png_bytep    chunk_list;      /* List of png_byte[5]; the textual chunk name
+                                  * followed by a PNG_HANDLE_* byte */
 #endif
 
 /* New members added in libpng-1.0.3 */
@@ -333,16 +449,24 @@ struct png_struct_def
 #endif
 
 /* New member added in libpng-1.0.25 and 1.2.17 */
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
-   /* Storage for unknown chunk that the library doesn't recognize. */
+#ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+   /* Temporary storage for unknown chunk that the library doesn't recognize,
+    * used while reading the chunk.
+    */
    png_unknown_chunk unknown_chunk;
 #endif
 
 /* New member added in libpng-1.2.26 */
   png_size_t old_big_row_buf_size;
 
+#ifdef PNG_READ_SUPPORTED
 /* New member added in libpng-1.2.30 */
-  png_charp chunkdata;  /* buffer for reading chunk data */
+  png_bytep        read_buffer;      /* buffer for reading chunk data */
+  png_alloc_size_t read_buffer_size; /* current size of the buffer */
+#endif
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+  uInt             IDAT_read_size;   /* limit on read buffer size for IDAT */
+#endif
 
 #ifdef PNG_IO_STATE_SUPPORTED
 /* New member added in libpng-1.4.0 */
@@ -356,9 +480,10 @@ struct png_struct_def
    void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
       png_bytep row, png_const_bytep prev_row);
 
-   /* Options */
-#ifdef PNG_SET_OPTION_SUPPORTED
-   png_byte options;           /* On/off state (up to 4 options) */
+#ifdef PNG_READ_SUPPORTED
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+   png_colorspace   colorspace;
+#endif
 #endif
 };
 #endif /* PNGSTRUCT_H */

pngtest.c

@@ -1,7 +1,7 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.5.15 [March 28, 2013]
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
  * 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.)
@@ -43,6 +43,9 @@
 
 #include "png.h"
 
+/* Known chunks that exist in pngtest.png must be supported or pngtest will fail
+ * simply as a result of re-ordering them.  This may be fixed in 1.7
+ */
 #if defined PNG_READ_SUPPORTED && /* else nothing can be done */\
    defined PNG_READ_bKGD_SUPPORTED &&\
    defined PNG_READ_cHRM_SUPPORTED &&\
@@ -570,7 +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;
          }
@@ -589,7 +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 */
@@ -779,7 +784,7 @@ write_chunks(png_structp write_ptr, int location)
  */
 #ifdef PNG_TEXT_SUPPORTED
 static void
-pngtest_check_text_support(png_structp png_ptr, png_textp text_ptr,
+pngtest_check_text_support(png_const_structp png_ptr, png_textp text_ptr,
    int num_text)
 {
    while (num_text > 0)
@@ -1186,7 +1191,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    }
 #endif
 #ifdef PNG_sCAL_SUPPORTED
-#ifdef PNG_FLOATING_POINT_SUPPORTED
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && \
+   defined(PNG_FLOATING_ARITHMETIC_SUPPORTED)
    {
       int unit;
       double scal_width, scal_height;
@@ -1248,15 +1254,15 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       {
          png_set_tIME(write_ptr, write_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
-         /* We have to use memcpy instead of "=" because the string
-          * pointed to by png_convert_to_rfc1123() gets free'ed before
-          * we use it.
-          */
-         memcpy(tIME_string,
-                    png_convert_to_rfc1123(read_ptr, mod_time),
-                    png_sizeof(tIME_string));
+         if (png_convert_to_rfc1123_buffer(tIME_string, mod_time))
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
+
+         else
+         {
+            strncpy(tIME_string, "*** invalid time ***", (sizeof tIME_string));
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
+         }
 
-         tIME_string[png_sizeof(tIME_string) - 1] = '\0';
          tIME_chunk_present++;
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
       }
@@ -1387,11 +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");
@@ -1432,14 +1440,15 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       {
          png_set_tIME(write_ptr, write_end_info_ptr, mod_time);
 #ifdef PNG_TIME_RFC1123_SUPPORTED
-         /* We have to use memcpy instead of "=" because the string
-            pointed to by png_convert_to_rfc1123() gets free'ed before
-            we use it */
-         memcpy(tIME_string,
-                    png_convert_to_rfc1123(read_ptr, mod_time),
-                    png_sizeof(tIME_string));
+         if (png_convert_to_rfc1123_buffer(tIME_string, mod_time))
+            tIME_string[(sizeof tIME_string) - 1] = '\0';
+
+         else
+         {
+            strncpy(tIME_string, "*** invalid time ***", sizeof tIME_string);
+            tIME_string[(sizeof tIME_string)-1] = '\0';
+         }
 
-         tIME_string[png_sizeof(tIME_string) - 1] = '\0';
          tIME_chunk_present++;
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
       }
@@ -1571,14 +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);
 
@@ -1957,9 +1964,10 @@ main(void)
 {
    fprintf(STDERR,
       " test ignored because libpng was not built with read support\n");
-   return 0;
+   /* And skip this test */
+   return 77;
 }
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_5_18beta01 Your_png_h_is_not_version_1_5_18beta01;
+typedef png_libpng_version_1_6_8rc02 Your_png_h_is_not_version_1_6_8rc02;

pngtrans.c

@@ -1,8 +1,8 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.5.11 [June 14, 2012]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.2 [April 25, 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.)
  *
@@ -18,7 +18,7 @@
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
 /* Turn on BGR-to-RGB mapping */
 void PNGAPI
-png_set_bgr(png_structp png_ptr)
+png_set_bgr(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_bgr");
 
@@ -32,7 +32,7 @@ png_set_bgr(png_structp png_ptr)
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
 /* Turn on 16 bit byte swapping */
 void PNGAPI
-png_set_swap(png_structp png_ptr)
+png_set_swap(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_swap");
 
@@ -47,7 +47,7 @@ png_set_swap(png_structp png_ptr)
 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
 /* Turn on pixel packing */
 void PNGAPI
-png_set_packing(png_structp png_ptr)
+png_set_packing(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_packing");
 
@@ -65,7 +65,7 @@ png_set_packing(png_structp png_ptr)
 #if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 /* Turn on packed pixel swapping */
 void PNGAPI
-png_set_packswap(png_structp png_ptr)
+png_set_packswap(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_packswap");
 
@@ -79,7 +79,7 @@ png_set_packswap(png_structp png_ptr)
 
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 void PNGAPI
-png_set_shift(png_structp png_ptr, png_const_color_8p true_bits)
+png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
 {
    png_debug(1, "in png_set_shift");
 
@@ -94,7 +94,7 @@ png_set_shift(png_structp png_ptr, png_const_color_8p true_bits)
 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
     defined(PNG_WRITE_INTERLACING_SUPPORTED)
 int PNGAPI
-png_set_interlace_handling(png_structp png_ptr)
+png_set_interlace_handling(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_interlace handling");
 
@@ -115,44 +115,91 @@ png_set_interlace_handling(png_structp png_ptr)
  * that don't like bytes as parameters.
  */
 void PNGAPI
-png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
+png_set_filler(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
 {
    png_debug(1, "in png_set_filler");
 
    if (png_ptr == NULL)
       return;
 
+   /* In libpng 1.6 it is possible to determine whether this is a read or write
+    * operation and therefore to do more checking here for a valid call.
+    */
+   if (png_ptr->mode & PNG_IS_READ_STRUCT)
+   {
+#     ifdef PNG_READ_FILLER_SUPPORTED
+         /* On read png_set_filler is always valid, regardless of the base PNG
+          * format, because other transformations can give a format where the
+          * filler code can execute (basically an 8 or 16-bit component RGB or G
+          * format.)
+          *
+          * NOTE: usr_channels is not used by the read code!  (This has led to
+          * confusion in the past.)  The filler is only used in the read code.
+          */
+         png_ptr->filler = (png_uint_16)filler;
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on read");
+         PNG_UNUSED(filler) /* not used in the write case */
+         return;
+#     endif
+   }
+
+   else /* write */
+   {
+#     ifdef PNG_WRITE_FILLER_SUPPORTED
+         /* On write the usr_channels parameter must be set correctly at the
+          * start to record the number of channels in the app-supplied data.
+          */
+         switch (png_ptr->color_type)
+         {
+            case PNG_COLOR_TYPE_RGB:
+               png_ptr->usr_channels = 4;
+               break;
+
+            case PNG_COLOR_TYPE_GRAY:
+               if (png_ptr->bit_depth >= 8)
+               {
+                  png_ptr->usr_channels = 2;
+                  break;
+               }
+
+               else
+               {
+                  /* There simply isn't any code in libpng to strip out bits
+                   * from bytes when the components are less than a byte in
+                   * size!
+                   */
+                  png_app_error(png_ptr,
+                     "png_set_filler is invalid for low bit depth gray output");
+                  return;
+               }
+
+            default:
+               png_app_error(png_ptr,
+                  "png_set_filler: inappropriate color type");
+               return;
+         }
+#     else
+         png_app_error(png_ptr, "png_set_filler not supported on write");
+         return;
+#     endif
+   }
+
+   /* Here on success - libpng supports the operation, set the transformation
+    * and the flag to say where the filler channel is.
+    */
    png_ptr->transformations |= PNG_FILLER;
-   png_ptr->filler = (png_uint_16)filler;
 
    if (filler_loc == PNG_FILLER_AFTER)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
 
    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
-
-   /* This should probably go in the "do_read_filler" routine.
-    * I attempted to do that in libpng-1.0.1a but that caused problems
-    * so I restored it in libpng-1.0.2a
-   */
-
-   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
-   {
-      png_ptr->usr_channels = 4;
-   }
-
-   /* Also I added this in libpng-1.0.2a (what happens when we expand
-    * a less-than-8-bit grayscale to GA?) */
-
-   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
-   {
-      png_ptr->usr_channels = 2;
-   }
 }
 
 /* Added to libpng-1.2.7 */
 void PNGAPI
-png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
+png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int filler_loc)
 {
    png_debug(1, "in png_set_add_alpha");
 
@@ -160,7 +207,9 @@ png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
       return;
 
    png_set_filler(png_ptr, filler, filler_loc);
-   png_ptr->transformations |= PNG_ADD_ALPHA;
+   /* The above may fail to do anything. */
+   if (png_ptr->transformations & PNG_FILLER)
+      png_ptr->transformations |= PNG_ADD_ALPHA;
 }
 
 #endif
@@ -168,7 +217,7 @@ png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
 void PNGAPI
-png_set_swap_alpha(png_structp png_ptr)
+png_set_swap_alpha(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_swap_alpha");
 
@@ -182,7 +231,7 @@ png_set_swap_alpha(png_structp png_ptr)
 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
 void PNGAPI
-png_set_invert_alpha(png_structp png_ptr)
+png_set_invert_alpha(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_invert_alpha");
 
@@ -195,7 +244,7 @@ png_set_invert_alpha(png_structp png_ptr)
 
 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
 void PNGAPI
-png_set_invert_mono(png_structp png_ptr)
+png_set_invert_mono(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_invert_mono");
 
@@ -623,7 +672,7 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
     defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
 /* Added at libpng-1.5.10 */
 void /* PRIVATE */
-png_do_check_palette_indexes(png_structp png_ptr, png_row_infop row_info)
+png_do_check_palette_indexes(png_structrp png_ptr, png_row_infop row_info)
 {
    if (png_ptr->num_palette < (1 << row_info->bit_depth) &&
       png_ptr->num_palette > 0) /* num_palette can be 0 in MNG files */
@@ -726,13 +775,24 @@ png_do_check_palette_indexes(png_structp png_ptr, png_row_infop row_info)
     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
 void PNGAPI
-png_set_user_transform_info(png_structp png_ptr, png_voidp
+png_set_user_transform_info(png_structrp png_ptr, png_voidp
    user_transform_ptr, int user_transform_depth, int user_transform_channels)
 {
    png_debug(1, "in png_set_user_transform_info");
 
    if (png_ptr == NULL)
       return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
+   if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+      (png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
+   {
+      png_app_error(png_ptr,
+            "info change after png_start_read_image or png_read_update_info");
+      return;
+   }
+#endif
+
    png_ptr->user_transform_ptr = user_transform_ptr;
    png_ptr->user_transform_depth = (png_byte)user_transform_depth;
    png_ptr->user_transform_channels = (png_byte)user_transform_channels;
@@ -746,18 +806,18 @@ png_set_user_transform_info(png_structp png_ptr, png_voidp
  */
 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
 png_voidp PNGAPI
-png_get_user_transform_ptr(png_const_structp png_ptr)
+png_get_user_transform_ptr(png_const_structrp png_ptr)
 {
    if (png_ptr == NULL)
       return (NULL);
 
-   return ((png_voidp)png_ptr->user_transform_ptr);
+   return png_ptr->user_transform_ptr;
 }
 #endif
 
 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
 png_uint_32 PNGAPI
-png_get_current_row_number(png_const_structp png_ptr)
+png_get_current_row_number(png_const_structrp png_ptr)
 {
    /* See the comments in png.h - this is the sub-image row when reading and
     * interlaced image.
@@ -769,7 +829,7 @@ png_get_current_row_number(png_const_structp png_ptr)
 }
 
 png_byte PNGAPI
-png_get_current_pass_number(png_const_structp png_ptr)
+png_get_current_pass_number(png_const_structrp png_ptr)
 {
    if (png_ptr != NULL)
       return png_ptr->pass;

pngwio.c

@@ -1,8 +1,8 @@
 
 /* pngwio.c - functions for data output
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.8 [(PENDING RELEASE)]
+ * 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.)
  *
@@ -30,11 +30,12 @@
  */
 
 void /* PRIVATE */
-png_write_data(png_structp png_ptr, png_const_bytep data, png_size_t length)
+png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length)
 {
    /* NOTE: write_data_fn must not change the buffer! */
    if (png_ptr->write_data_fn != NULL )
-      (*(png_ptr->write_data_fn))(png_ptr, (png_bytep)data, length);
+      (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
+         length);
 
    else
       png_error(png_ptr, "Call to NULL write function");
@@ -46,7 +47,6 @@ png_write_data(png_structp png_ptr, png_const_bytep data, png_size_t length)
  * write_data function and use it at run time with png_set_write_fn(), rather
  * than changing the library.
  */
-#ifndef USE_FAR_KEYWORD
 void PNGCBAPI
 png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
@@ -60,64 +60,6 @@ png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
    if (check != length)
       png_error(png_ptr, "Write Error");
 }
-#else
-/* This is the model-independent version. Since the standard I/O library
- * can't handle far buffers in the medium and small models, we have to copy
- * the data.
- */
-
-#define NEAR_BUF_SIZE 1024
-#define MIN(a,b) (a <= b ? a : b)
-
-void PNGCBAPI
-png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
-   png_uint_32 check;
-   png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
-   png_FILE_p io_ptr;
-
-   if (png_ptr == NULL)
-      return;
-
-   /* Check if data really is near. If so, use usual code. */
-   near_data = (png_byte *)CVT_PTR_NOCHECK(data);
-   io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
-
-   if ((png_bytep)near_data == data)
-   {
-      check = fwrite(near_data, 1, length, io_ptr);
-   }
-
-   else
-   {
-      png_byte buf[NEAR_BUF_SIZE];
-      png_size_t written, remaining, err;
-      check = 0;
-      remaining = length;
-
-      do
-      {
-         written = MIN(NEAR_BUF_SIZE, remaining);
-         png_memcpy(buf, data, written); /* Copy far buffer to near buffer */
-         err = fwrite(buf, 1, written, io_ptr);
-
-         if (err != written)
-            break;
-
-         else
-            check += err;
-
-         data += written;
-         remaining -= written;
-      }
-      while (remaining != 0);
-   }
-
-   if (check != length)
-      png_error(png_ptr, "Write Error");
-}
-
-#endif
 #endif
 
 /* This function is called to output any data pending writing (normally
@@ -126,7 +68,7 @@ png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
  */
 #ifdef PNG_WRITE_FLUSH_SUPPORTED
 void /* PRIVATE */
-png_flush(png_structp png_ptr)
+png_flush(png_structrp png_ptr)
 {
    if (png_ptr->output_flush_fn != NULL)
       (*(png_ptr->output_flush_fn))(png_ptr);
@@ -141,7 +83,7 @@ png_default_flush(png_structp png_ptr)
    if (png_ptr == NULL)
       return;
 
-   io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
+   io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
    fflush(io_ptr);
 }
 #  endif
@@ -177,7 +119,7 @@ png_default_flush(png_structp png_ptr)
  *                 *FILE structure.
  */
 void PNGAPI
-png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
+png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
     png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
 {
    if (png_ptr == NULL)
@@ -207,6 +149,8 @@ png_set_write_fn(png_structp 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 */
@@ -219,36 +163,4 @@ png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
           " same structure");
    }
 }
-
-#ifdef USE_FAR_KEYWORD
-#  ifdef _MSC_VER
-void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
-{
-   void *near_ptr;
-   void FAR *far_ptr;
-   FP_OFF(near_ptr) = FP_OFF(ptr);
-   far_ptr = (void FAR *)near_ptr;
-
-   if (check != 0)
-      if (FP_SEG(ptr) != FP_SEG(far_ptr))
-         png_error(png_ptr, "segment lost in conversion");
-
-   return(near_ptr);
-}
-#  else
-void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
-{
-   void *near_ptr;
-   void FAR *far_ptr;
-   near_ptr = (void FAR *)ptr;
-   far_ptr = (void FAR *)near_ptr;
-
-   if (check != 0)
-      if (far_ptr != ptr)
-         png_error(png_ptr, "segment lost in conversion");
-
-   return(near_ptr);
-}
-#  endif
-#endif
 #endif /* PNG_WRITE_SUPPORTED */

pngwtran.c

@@ -1,8 +1,8 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.5.13 [September 27, 2012]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.0 [February 14, 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.)
  *
@@ -20,7 +20,7 @@
  * transformations is significant.
  */
 void /* PRIVATE */
-png_do_write_transformations(png_structp png_ptr, png_row_infop row_info)
+png_do_write_transformations(png_structrp png_ptr, png_row_infop row_info)
 {
    png_debug(1, "in png_do_write_transformations");
 
@@ -45,20 +45,8 @@ png_do_write_transformations(png_structp png_ptr, png_row_infop row_info)
 
 #ifdef PNG_WRITE_FILLER_SUPPORTED
    if (png_ptr->transformations & PNG_FILLER)
-   {
-      if (png_ptr->color_type & (PNG_COLOR_MASK_ALPHA|PNG_COLOR_MASK_PALETTE))
-      {
-         /* GA, RGBA or palette; in any of these cases libpng will not do the
-          * the correct thing (whatever that might be).
-          */
-         png_warning(png_ptr, "incorrect png_set_filler call ignored");
-         png_ptr->transformations &= ~PNG_FILLER;
-      }
-
-      else
-         png_do_strip_channel(row_info, png_ptr->row_buf + 1,
-            !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
-   }
+      png_do_strip_channel(row_info, png_ptr->row_buf + 1,
+         !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
 #endif
 
 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED
@@ -299,7 +287,7 @@ png_do_shift(png_row_infop row_info, png_bytep row,
       {
          png_bytep bp = row;
          png_size_t i;
-         png_byte mask;
+         unsigned int mask;
          png_size_t row_bytes = row_info->rowbytes;
 
          if (bit_depth->gray == 1 && row_info->bit_depth == 2)
@@ -313,20 +301,22 @@ png_do_shift(png_row_infop row_info, png_bytep row,
 
          for (i = 0; i < row_bytes; i++, bp++)
          {
-            png_uint_16 v;
             int j;
+            unsigned int v, out;
 
             v = *bp;
-            *bp = 0;
+            out = 0;
 
             for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
             {
                if (j > 0)
-                  *bp |= (png_byte)((v << j) & 0xff);
+                  out |= v << j;
 
                else
-                  *bp |= (png_byte)((v >> (-j)) & mask);
+                  out |= (v >> (-j)) & mask;
             }
+
+            *bp = (png_byte)(out & 0xff);
          }
       }
 
@@ -339,21 +329,23 @@ png_do_shift(png_row_infop row_info, png_bytep row,
          for (i = 0; i < istop; i++, bp++)
          {
 
-            png_uint_16 v;
+            const unsigned int c = i%channels;
             int j;
-            int c = (int)(i%channels);
+            unsigned int v, out;
 
             v = *bp;
-            *bp = 0;
+            out = 0;
 
             for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
             {
                if (j > 0)
-                  *bp |= (png_byte)((v << j) & 0xff);
+                  out |= v << j;
 
                else
-                  *bp |= (png_byte)((v >> (-j)) & 0xff);
+                  out |= v >> (-j);
             }
+
+            *bp = (png_byte)(out & 0xff);
          }
       }
 
@@ -365,22 +357,22 @@ png_do_shift(png_row_infop row_info, png_bytep row,
 
          for (bp = row, i = 0; i < istop; i++)
          {
-            int c = (int)(i%channels);
-            png_uint_16 value, v;
+            const unsigned int c = i%channels;
             int j;
+            unsigned int value, v;
 
-            v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));
+            v = png_get_uint_16(bp);
             value = 0;
 
             for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
             {
                if (j > 0)
-                  value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
+                  value |= v << j;
 
                else
-                  value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
+                  value |= v >> (-j);
             }
-            *bp++ = (png_byte)(value >> 8);
+            *bp++ = (png_byte)((value >> 8) & 0xff);
             *bp++ = (png_byte)(value & 0xff);
          }
       }

projects/owatcom/libpng.wpj

@@ -7,7 +7,7 @@ WRect
 256
 0
 8960
-9284
+9294
 2
 MProject
 3
@@ -25,7 +25,7 @@ $(MAKE) $(__MAKEOPTS__) -f pngconfig.mak
 MCommand
 19
 @type pngconfig.inf
-3
+4
 5
 WFileName
 10
@@ -39,54 +39,74 @@ WFileName
 12
 pngvalid.tgt
 8
-WVList
-3
+WFileName
+12
+pngstest.tgt
 9
-VComponent
+WVList
+4
 10
+VComponent
+11
 WRect
 0
 0
-5632
-4164
+5638
+4174
 0
 0
-11
+12
 WFileName
 10
 libpng.tgt
 0
 0
-12
-VComponent
 13
+VComponent
+14
 WRect
 1280
-1540
-5632
-4164
+1550
+5638
+4174
 0
 0
-14
+15
 WFileName
 11
 pngtest.tgt
 0
 1
-15
-VComponent
 16
-WRect
-518
-487
-5632
-4164
-0
-0
+VComponent
 17
+WRect
+524
+497
+5638
+4174
+0
+0
+18
 WFileName
 12
 pngvalid.tgt
 0
 1
-9
+19
+VComponent
+20
+WRect
+2054
+2701
+5674
+4232
+0
+0
+21
+WFileName
+12
+pngstest.tgt
+0
+1
+19

projects/owatcom/pngstest.tgt

@@ -0,0 +1,219 @@
+40
+targetIdent
+0
+MProject
+1
+MComponent
+0
+2
+WString
+4
+NEXE
+3
+WString
+5
+nc2en
+1
+0
+0
+4
+MCommand
+0
+5
+MCommand
+1118
+pngstest --strict --log ../../contrib/pngsuite/basn0g01.png ../../contrib/pngsuite/basn0g02.png ../../contrib/pngsuite/basn0g04.png ../../contrib/pngsuite/basn0g08.png ../../contrib/pngsuite/basn0g16.png ../../contrib/pngsuite/basn2c08.png ../../contrib/pngsuite/basn2c16.png ../../contrib/pngsuite/basn3p01.png ../../contrib/pngsuite/basn3p02.png ../../contrib/pngsuite/basn3p04.png ../../contrib/pngsuite/basn3p08.png ../../contrib/pngsuite/basn4a08.png ../../contrib/pngsuite/basn4a16.png ../../contrib/pngsuite/basn6a08.png ../../contrib/pngsuite/basn6a16.png ../../contrib/pngsuite/ftbbn0g04.png ../../contrib/pngsuite/ftbbn0g01.png ../../contrib/pngsuite/ftbbn0g02.png ../../contrib/pngsuite/ftbbn2c16.png ../../contrib/pngsuite/ftbbn3p08.png ../../contrib/pngsuite/ftbgn2c16.png ../../contrib/pngsuite/ftbgn3p08.png ../../contrib/pngsuite/ftbrn2c08.png ../../contrib/pngsuite/ftbwn0g16.png ../../contrib/pngsuite/ftbwn3p08.png ../../contrib/pngsuite/ftbyn3p08.png ../../contrib/pngsuite/ftp0n0g08.png ../../contrib/pngsuite/ftp0n2c08.png ../../contrib/pngsuite/ftp0n3p08.png ../../contrib/pngsuite/ftp1n3p08.png
+6
+MItem
+12
+pngstest.exe
+7
+WString
+4
+NEXE
+8
+WVList
+6
+9
+MVState
+10
+WString
+7
+WINLINK
+11
+WString
+11
+?????Stack:
+1
+12
+WString
+4
+768k
+0
+13
+MVState
+14
+WString
+7
+WINLINK
+15
+WString
+28
+?????Library directories(;):
+1
+16
+WString
+8
+$(%zlib)
+0
+17
+MVState
+18
+WString
+7
+WINLINK
+19
+WString
+18
+?????Libraries(,):
+1
+20
+WString
+19
+libpng.lib zlib.lib
+0
+21
+MVState
+22
+WString
+7
+WINLINK
+23
+WString
+11
+?????Stack:
+0
+24
+WString
+4
+768k
+0
+25
+MVState
+26
+WString
+7
+WINLINK
+27
+WString
+28
+?????Library directories(;):
+0
+28
+WString
+8
+$(%zlib)
+0
+29
+MVState
+30
+WString
+7
+WINLINK
+31
+WString
+18
+?????Libraries(,):
+0
+32
+WString
+19
+libpng.lib zlib.lib
+0
+33
+WVList
+1
+34
+ActionStates
+35
+WString
+4
+&Run
+36
+WVList
+0
+-1
+1
+1
+0
+37
+WPickList
+2
+38
+MItem
+3
+*.c
+39
+WString
+4
+COBJ
+40
+WVList
+2
+41
+MVState
+42
+WString
+3
+WCC
+43
+WString
+25
+n????Include directories:
+1
+44
+WString
+39
+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
+45
+MVState
+46
+WString
+3
+WCC
+47
+WString
+25
+n????Include directories:
+0
+48
+WString
+39
+"$(%zlib);$(%watcom)/h;$(%watcom)/h/nt"
+0
+49
+WVList
+0
+-1
+1
+1
+0
+50
+MItem
+33
+..\..\contrib\libtests\pngstest.c
+51
+WString
+4
+COBJ
+52
+WVList
+0
+53
+WVList
+0
+38
+1
+1
+0

projects/visualc71/README.txt

@@ -37,9 +37,9 @@ To use:
 
 This project builds the libpng binaries as follows:
 
-* Win32_DLL_Release\libpng15.dll      DLL build
-* Win32_DLL_Debug\libpng15d.dll       DLL build (debug version)
-* Win32_DLL_VB\libpng15vb.dll         DLL build for Visual Basic, using stdcall
+* Win32_DLL_Release\libpng16.dll      DLL build
+* Win32_DLL_Debug\libpng16d.dll       DLL build (debug version)
+* Win32_DLL_VB\libpng16vb.dll         DLL build for Visual Basic, using stdcall
 * Win32_LIB_Release\libpng.lib        static build
 * Win32_LIB_Debug\libpngd.lib         static build (debug version)
 

projects/visualc71/libpng.vcproj

@@ -30,7 +30,7 @@
 				Name="VCCustomBuildTool"/>
 			<Tool
 				Name="VCLinkerTool"
-				OutputFile="$(OutDir)/libpng15.dll"
+				OutputFile="$(OutDir)/libpng16.dll"
 				LinkIncremental="1"/>
 			<Tool
 				Name="VCMIDLTool"/>
@@ -78,7 +78,7 @@
 				Name="VCCustomBuildTool"/>
 			<Tool
 				Name="VCLinkerTool"
-				OutputFile="$(OutDir)/libpng15d.dll"
+				OutputFile="$(OutDir)/libpng16d.dll"
 				GenerateDebugInformation="TRUE"/>
 			<Tool
 				Name="VCMIDLTool"/>
@@ -126,7 +126,7 @@
 				Name="VCCustomBuildTool"/>
 			<Tool
 				Name="VCLinkerTool"
-				OutputFile="$(OutDir)/libpng15vb.dll"
+				OutputFile="$(OutDir)/libpng16vb.dll"
 				LinkIncremental="1"/>
 			<Tool
 				Name="VCMIDLTool"/>

projects/visualc71/pngtest.vcproj

@@ -130,7 +130,7 @@ $(TargetPath) ..\..\pngtest.png $(IntDir)\pngout.png"
 				Name="VCLinkerTool"
 				OutputFile="$(OutDir)/pngtest.exe"
 				LinkIncremental="1"
-				IgnoreDefaultLibraryNames="$(IntDir)\libpng15b.lib"
+				IgnoreDefaultLibraryNames="$(IntDir)\libpng16b.lib"
 				SubSystem="1"
 				TargetMachine="1"/>
 			<Tool

projects/vstudio/WARNING

@@ -1,23 +1,27 @@
 WARNING
 =======
-Libpng 1.5 erroneously uses /MD when building debug DLL versions of libpng.
-It should use /MDd - you can change this under properties\C/C++\Code
-Generation\Runtime Library if you need to use the debug runtime for debug
-builds.  This will be changed in libpng 1.6 but is currently retained for
-compatibility with older libpng 1.5 releases.
+Libpng 1.6 does not use the default run-time library when building static
+library builds of libpng; instead of the shared DLL runtime it uses a static
+runtime.  If you need to change this make sure to change the setting on all the
+relevant projects:
+
+libpng
+zlib
+all the test programs
 
 The runtime library settings for each build are as follows:
 
            Release        Debug
-DLL         /MD            /MD
+DLL         /MD            /MDd
 Library     /MT            /MTd
 
+NOTICE that libpng 1.5 erroneously used /MD for Debug DLL builds; if you used
+the debug builds in your app and you changed your app to use /MD you will need
+to change it to /MDd for libpng 1.6.
+
 The Visual Studio 2010 defaults for a Win32 DLL or Static Library project are
 as follows:
 
                  Release     Debug
 DLL               /MD         /MDd
 Static Library    /MD         /MDd
-
-Notice that by default static library builds use the DLL runtime, not the
-static library runtime.

projects/vstudio/libpng/libpng.vcxproj

@@ -63,23 +63,23 @@
     <LinkIncremental>false</LinkIncremental>
     <CustomBuildBeforeTargets>
     </CustomBuildBeforeTargets>
-    <TargetName>$(ProjectName)15</TargetName>
+    <TargetName>$(ProjectName)16</TargetName>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug Library|Win32'">
     <LinkIncremental>false</LinkIncremental>
     <CustomBuildBeforeTargets />
-    <TargetName>$(ProjectName)15</TargetName>
+    <TargetName>$(ProjectName)16</TargetName>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <LinkIncremental>false</LinkIncremental>
     <CustomBuildBeforeTargets>
     </CustomBuildBeforeTargets>
-    <TargetName>$(ProjectName)15</TargetName>
+    <TargetName>$(ProjectName)16</TargetName>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release Library|Win32'">
     <LinkIncremental>false</LinkIncremental>
     <CustomBuildBeforeTargets />
-    <TargetName>$(ProjectName)15</TargetName>
+    <TargetName>$(ProjectName)16</TargetName>
   </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
@@ -101,12 +101,13 @@
       <AdditionalIncludeDirectories>$(ZLibSrcDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <TreatWarningAsError>true</TreatWarningAsError>
       <Optimization>Disabled</Optimization>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
     </ClCompile>
     <Link>
       <SubSystem>Windows</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <AdditionalDependencies>zlib.lib</AdditionalDependencies>
-      <Version>15</Version>
+      <Version>16</Version>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
   </ItemDefinitionGroup>
@@ -163,7 +164,7 @@
       <EnableCOMDATFolding>true</EnableCOMDATFolding>
       <OptimizeReferences>true</OptimizeReferences>
       <AdditionalDependencies>zlib.lib</AdditionalDependencies>
-      <Version>15</Version>
+      <Version>16</Version>
       <AdditionalLibraryDirectories>$(OutDir)</AdditionalLibraryDirectories>
     </Link>
   </ItemDefinitionGroup>

projects/vstudio/pngstest/pngstest.vcxproj

@@ -0,0 +1,219 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug Library|Win32">
+      <Configuration>Debug Library</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release Library|Win32">
+      <Configuration>Release Library</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
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