[libpng17] Use a more generous size limit for IDAT chunks.

parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).

.travis.yml

@@ -0,0 +1,99 @@
+language: c
+sudo: false
+cache:
+    directories:
+        - $HOME/.cache/pip
+        - $HOME/deps
+matrix:
+    include:
+        - os: linux
+          compiler: gcc
+          env: BUILD_TYPE=normal
+        - os: linux
+          compiler: clang
+          env: BUILD_TYPE=normal
+        - os: linux
+          compiler: gcc
+          env: BUILD_TYPE=coverage
+        - os: linux
+          compiler: clang
+          env: BUILD_TYPE=ubsan
+        - os: linux
+          compiler: clang
+          env: BUILD_TYPE=asan
+        - os: linux
+          compiler: clang
+          env: BUILD_TYPE=lsan
+        - os: linux
+          compiler: clang
+          env: BUILD_TYPE=msan
+        - os: osx
+          compiler: gcc
+          env: BUILD_TYPE=normal
+        - os: osx
+          compiler: clang
+          env: BUILD_TYPE=normal
+
+install:
+    - pip install --user 'requests[security]'
+    - pip install --user cpp-coveralls
+    - |
+        mkdir -p deps
+        pushd deps
+        export PREFIXDIR=`pwd`
+        if [ ! -f "libtool-2.4.6.tar.xz" ]; then
+             wget http://ftpmirror.gnu.org/libtool/libtool-2.4.6.tar.xz
+        fi
+        if [ ! -f "automake-1.15.tar.xz" ]; then
+             wget http://ftp.gnu.org/gnu/automake/automake-1.15.tar.xz
+        fi
+        if [ ! -d "libtool-2.4.6" ]; then
+             tar xf libtool-2.4.6.tar.xz
+             pushd libtool-2.4.6/
+             ./configure --prefix=$PREFIXDIR
+             make && make install
+             popd
+             cp $PREFIXDIR/bin/libtool $PREFIXDIR/bin/glibtool
+             cp $PREFIXDIR/bin/libtoolize $PREFIXDIR/bin/glibtoolize
+        fi
+        if [ ! -d "automake-1.15" ]; then
+             tar xf automake-1.15.tar.xz
+             pushd automake-1.15/
+             ./configure --prefix=$PREFIXDIR
+             make && make install
+             popd
+        fi
+        export PATH="$PREFIXDIR/bin:$PATH"
+        popd
+before_script:
+    - |
+        if [ "$BUILD_TYPE" = "coverage" ]; then
+             export CFLAGS="-fprofile-arcs -ftest-coverage"
+             export LDFLAGS="-fprofile-arcs -ftest-coverage"
+        fi
+    - |
+         if [ "$BUILD_TYPE" = "asan" ]; then
+             export CFLAGS=-fsanitize=address
+             export LDFLAGS=-fsanitize=address
+         fi
+    - |
+         if [ "$BUILD_TYPE" = "lsan" ]; then
+             export CFLAGS=-fsanitize=leak
+             export LDFLAGS=-fsanitize=leak
+         fi
+    - |
+         if [ "$BUILD_TYPE" = "msan" ]; then
+             export CFLAGS=-fsanitize=memory
+             export LDFLAGS=-fsanitize=memory
+         fi
+    - |
+         if [ "$BUILD_TYPE" = "ubsan" ]; then
+             export CFLAGS="-fsanitize=undefined -fno-sanitize-recover"
+             export LDFLAGS="-fsanitize=undefined"
+         fi
+script:
+    - ./autogen.sh && ./configure && make && make check
+    - |
+          if [ "$BUILD_TYPE" = "coverage" ]; then
+              cpp-coveralls --gcov-options '\-lp'
+          fi

CMakeLists.txt

@@ -1,6 +1,6 @@
 # CMakeLists.txt
 
-# Copyright (C) 2007,2009-2017 Glenn Randers-Pehrson
+# Copyright (C) 2007,2009-2016 Glenn Randers-Pehrson
 # Written by Christian Ehrlicher, 2007
 # Revised by Roger Lowman, 2009-2010
 # Revised by Clifford Yapp, 2011-2012
@@ -11,8 +11,8 @@
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h
 
-cmake_minimum_required(VERSION 3.0.2)
-cmake_policy(VERSION 3.0.2)
+cmake_minimum_required(VERSION 2.8.3)
+cmake_policy(VERSION 2.8.3)
 
 # Set MacOSX @rpath usage globally.
 if (POLICY CMP0020)
@@ -35,23 +35,14 @@ project(libpng C)
 enable_testing()
 
 set(PNGLIB_MAJOR 1)
-set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 32)
+set(PNGLIB_MINOR 7)
+set(PNGLIB_RELEASE 0)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
-include(GNUInstallDirs)
-
 # needed packages
-
-#Allow users to specify location of Zlib,
-# Useful if zlib is being built alongside this as a sub-project
-option(PNG_BUILD_ZLIB "Custom zlib Location, else find_package is used" OFF)
-
-IF(NOT PNG_BUILD_ZLIB)
-  find_package(ZLIB REQUIRED)
-  include_directories(${ZLIB_INCLUDE_DIR})
-ENDIF(NOT PNG_BUILD_ZLIB)
+find_package(ZLIB REQUIRED)
+include_directories(${ZLIB_INCLUDE_DIR})
 
 if(NOT WIN32)
   find_library(M_LIBRARY
@@ -76,16 +67,12 @@ option(PNG_FRAMEWORK "Build OS X framework" OFF)
 option(PNG_DEBUG     "Build with debug output" OFF)
 option(PNGARG        "Disable ANSI-C prototypes" OFF)
 
-option(PNG_HARDWARE_OPTIMIZATIONS "Enable Hardware Optimizations" ON)
-
-
 set(PNG_PREFIX "" CACHE STRING "Prefix to add to the API function names")
 set(DFA_XTRA "" CACHE FILEPATH "File containing extra configuration settings")
 
-if(PNG_HARDWARE_OPTIMIZATIONS)
 # set definitions and sources for arm
-if(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" OR
-  CMAKE_SYSTEM_PROCESSOR MATCHES "^aarch64")
+if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "^arm" OR
+  ${CMAKE_SYSTEM_PROCESSOR} MATCHES "^aarch64")
   set(PNG_ARM_NEON_POSSIBLE_VALUES check on off)
   set(PNG_ARM_NEON "check" CACHE STRING "Enable ARM NEON optimizations:
      check: (default) use internal checking code;
@@ -102,7 +89,7 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" OR
       arm/arm_init.c
       arm/filter_neon.S
       arm/filter_neon_intrinsics.c)
-
+      
     if(${PNG_ARM_NEON} STREQUAL "on")
       add_definitions(-DPNG_ARM_NEON_OPT=2)
     elseif(${PNG_ARM_NEON} STREQUAL "check")
@@ -113,79 +100,6 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "^arm" OR
   endif()
 endif()
 
-# set definitions and sources for powerpc
-if(CMAKE_SYSTEM_PROCESSOR MATCHES "^powerpc*" OR
-	CMAKE_SYSTEM_PROCESSOR MATCHES "^ppc64*" )
-  set(PNG_POWERPC_VSX_POSSIBLE_VALUES on off)
-  set(PNG_POWERPC_VSX "on" CACHE STRING "Enable POWERPC VSX optimizations:
-     off: disable the optimizations.")
-  set_property(CACHE PNG_POWERPC_VSX PROPERTY STRINGS
-     ${PNG_POWERPC_VSX_POSSIBLE_VALUES})
-  list(FIND PNG_POWERPC_VSX_POSSIBLE_VALUES ${PNG_POWERPC_VSX} index)
-  if(index EQUAL -1)
-    message(FATAL_ERROR
-      " PNG_POWERPC_VSX must be one of [${PNG_POWERPC_VSX_POSSIBLE_VALUES}]")
-  elseif(NOT ${PNG_POWERPC_VSX} STREQUAL "no")
-    set(libpng_powerpc_sources
-      powerpc/powerpc_init.c
-      powerpc/filter_vsx_intrinsics.c)
-    if(${PNG_POWERPC_VSX} STREQUAL "on")
-      add_definitions(-DPNG_POWERPC_VSX_OPT=2)
-    endif()
-  else()
-    add_definitions(-DPNG_POWERPC_VSX_OPT=0)
-  endif()
-endif()
-
-# set definitions and sources for intel
-if(CMAKE_SYSTEM_PROCESSOR MATCHES "^i?86" OR
-	CMAKE_SYSTEM_PROCESSOR MATCHES "^x86_64*" )
-  set(PNG_INTEL_SSE_POSSIBLE_VALUES on off)
-  set(PNG_INTEL_SSE "on" CACHE STRING "Enable INTEL_SSE optimizations:
-     off: disable the optimizations")
-  set_property(CACHE PNG_INTEL_SSE PROPERTY STRINGS
-     ${PNG_INTEL_SSE_POSSIBLE_VALUES})
-  list(FIND PNG_INTEL_SSE_POSSIBLE_VALUES ${PNG_INTEL_SSE} index)
-  if(index EQUAL -1)
-    message(FATAL_ERROR
-      " PNG_INTEL_SSE must be one of [${PNG_INTEL_SSE_POSSIBLE_VALUES}]")
-  elseif(NOT ${PNG_INTEL_SSE} STREQUAL "no")
-    set(libpng_intel_sources
-      intel/intel_init.c
-      intel/filter_sse2_intrinsics.c)
-    if(${PNG_INTEL_SSE} STREQUAL "on")
-      add_definitions(-DPNG_INTEL_SSE_OPT=1)
-    endif()
-  else()
-    add_definitions(-DPNG_INTEL_SSE_OPT=0)
-  endif()
-endif()
-
-# set definitions and sources for MIPS
-if(CMAKE_SYSTEM_PROCESSOR MATCHES "mipsel*" OR
-	CMAKE_SYSTEM_PROCESSOR MATCHES "mips64el*" )
-  set(PNG_MIPS_MSA_POSSIBLE_VALUES on off)
-  set(PNG_MIPS_MSA "on" CACHE STRING "Enable MIPS_MSA optimizations:
-     off: disable the optimizations")
-  set_property(CACHE PNG_MIPS_MSA PROPERTY STRINGS
-     ${PNG_MIPS_MSA_POSSIBLE_VALUES})
-  list(FIND PNG_MIPS_MSA_POSSIBLE_VALUES ${PNG_MIPS_MSA} index)
-  if(index EQUAL -1)
-    message(FATAL_ERROR
-      " PNG_MIPS_MSA must be one of [${PNG_MIPS_MSA_POSSIBLE_VALUES}]")
-  elseif(NOT ${PNG_MIPS_MSA} STREQUAL "no")
-    set(libpng_mips_sources
-      mips/mips_init.c
-      mips/filter_msa_intrinsics.c)
-    if(${PNG_MIPS_MSA} STREQUAL "on")
-      add_definitions(-DPNG_MIPS_MSA_OPT=2)
-    endif()
-  else()
-    add_definitions(-DPNG_MIPS_MSA_OPT=0)
-  endif()
-endif()
-endif(PNG_HARDWARE_OPTIMIZATIONS)
-
 # SET LIBNAME
 set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
 
@@ -454,6 +368,7 @@ set(libpng_private_hdrs
   pngdebug.h
   pnginfo.h
   pngstruct.h
+  pngchunk.h
 )
 if(AWK)
   list(APPEND libpng_private_hdrs "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h")
@@ -477,9 +392,6 @@ set(libpng_sources
   pngwtran.c
   pngwutil.c
   ${libpng_arm_sources}
-  ${libpng_intel_sources}
-  ${libpng_mips_sources}
-  ${libpng_powerpc_sources}
 )
 set(pngtest_sources
   pngtest.c
@@ -755,58 +667,31 @@ if(PNG_SHARED)
   list(APPEND PNG_BIN_TARGETS png-fix-itxt)
 endif()
 
+# Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set
+IF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+  SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
+ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+
 # Set a variable with CMake code which:
 # Creates a symlink from src to dest (if possible) or alternatively
 # copies if different.
-include(CMakeParseArguments)
-
-function(CREATE_SYMLINK DEST_FILE)
-
-  cmake_parse_arguments(S "" "FILE;TARGET" "" ${ARGN})
-
-  if(NOT S_TARGET AND NOT S_FILE)
-    message(FATAL_ERROR "Specify either a TARGET or a FILE for CREATE_SYMLINK to link to.")
-  endif(NOT S_TARGET AND NOT S_FILE)
-
-  if(S_TARGET AND S_FILE)
-    message(FATAL_ERROR "CREATE_SYMLINK called with both source file ${S_FILE} and build target ${S_TARGET} arguments - can only handle 1 type per call.")
-  endif(S_TARGET AND S_FILE)
-
-  if(S_FILE)
-    # If we don't need to symlink something that's coming from a build target,
-    # we can go ahead and symlink/copy at configure time.
-
-    if(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
-      execute_process(
-	COMMAND "${CMAKE_COMMAND}" -E copy_if_different ${S_FILE} ${DEST_FILE}
-	WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
-	)
-    else(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
-      execute_process(
-	COMMAND ${CMAKE_COMMAND} -E create_symlink ${S_FILE} ${DEST_FILE}
-	WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}"
-	)
-    endif(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
-  endif(S_FILE)
-
-  if(S_TARGET)
-    # We need to use generator expressions, which can be a bit tricky, so for
-    # simplicity make the symlink a POST_BUILD step and use the TARGET
-    # signature of add_custom_command.
-
-    if(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
-      add_custom_command(TARGET ${S_TARGET} POST_BUILD
-	COMMAND "${CMAKE_COMMAND}" -E copy_if_different $<TARGET_LINKER_FILE_NAME:${S_TARGET}> $<TARGET_LINKER_FILE_DIR:${S_TARGET}>/${DEST_FILE}
-	)
-    else(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
-      add_custom_command(TARGET ${S_TARGET} POST_BUILD
-	COMMAND "${CMAKE_COMMAND}" -E create_symlink $<TARGET_LINKER_FILE_NAME:${S_TARGET}> $<TARGET_LINKER_FILE_DIR:${S_TARGET}>/${DEST_FILE}
-	)
-    endif(CMAKE_HOST_WIN32 AND NOT CYGWIN AND NOT MSYS)
-
-  endif(S_TARGET)
-
-endfunction()
+macro(CREATE_SYMLINK SRC_FILE DEST_FILE)
+  FILE(REMOVE ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  if(WIN32 AND NOT CYGWIN AND NOT MSYS)
+    ADD_CUSTOM_COMMAND(
+        OUTPUT ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}   ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        DEPENDS ${PNG_LIB_TARGETS}
+        )
+    ADD_CUSTOM_TARGET(${DEST_FILE}_COPY ALL DEPENDS ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  else(WIN32 AND NOT CYGWIN AND NOT MSYS)
+    get_filename_component(LINK_TARGET "${SRC_FILE}" NAME)
+    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_LIBRARY_OUTPUT_DIRECTORY})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+  endif(WIN32 AND NOT CYGWIN AND NOT MSYS)
+endmacro()
 
 # Create source generation scripts.
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genchk.cmake.in
@@ -834,19 +719,19 @@ if(NOT WIN32 OR CYGWIN OR MINGW)
   set(LIBS        "-lz -lm")
   configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
     ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
-  CREATE_SYMLINK(libpng.pc FILE ${PNGLIB_NAME}.pc)
+  CREATE_SYMLINK(${PNGLIB_NAME}.pc libpng.pc)
 
   configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
     ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY)
-  CREATE_SYMLINK(libpng-config FILE ${PNGLIB_NAME}-config)
+  CREATE_SYMLINK(${PNGLIB_NAME}-config libpng-config)
 endif(NOT WIN32 OR CYGWIN OR MINGW)
 
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(png PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.32
-    VERSION 16.${PNGLIB_RELEASE}.0
-    SOVERSION 16
+#   VERSION 17.${PNGLIB_RELEASE}.1.7.0beta90
+    VERSION 17.${PNGLIB_RELEASE}.0
+    SOVERSION 17
     CLEAN_DIRECT_OUTPUT 1)
 endif()
 
@@ -869,22 +754,28 @@ if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
       FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
   if(PNG_SHARED)
-    # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
+    # Create a symlink for libpng.dll.a => libpng17.dll.a on Cygwin
     if(CYGWIN OR MINGW)
-      CREATE_SYMLINK(libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} TARGET png)
-      install(FILES $<TARGET_LINKER_FILE_DIR:png>/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+       get_target_property(BUILD_TARGET_LOCATION png LOCATION_${CMAKE_BUILD_TYPE})
+       CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})
+       install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
     endif(CYGWIN OR MINGW)
 
     if(NOT WIN32)
-      CREATE_SYMLINK(libpng${CMAKE_SHARED_LIBRARY_SUFFIX} TARGET png)
-      install(FILES $<TARGET_LINKER_FILE_DIR:png>/libpng${CMAKE_SHARED_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+      get_target_property(BUILD_TARGET_LOCATION png LOCATION_${CMAKE_BUILD_TYPE})
+      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
     endif(NOT WIN32)
   endif(PNG_SHARED)
 
   if(PNG_STATIC)
     if(NOT WIN32 OR CYGWIN OR MINGW)
-      CREATE_SYMLINK( libpng${CMAKE_STATIC_LIBRARY_SUFFIX} TARGET png_static)
-      install(FILES $<TARGET_LINKER_FILE_DIR:png_static>/libpng${CMAKE_STATIC_LIBRARY_SUFFIX} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+      get_target_property(BUILD_TARGET_LOCATION png_static LOCATION_${CMAKE_BUILD_TYPE})
+      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
     endif(NOT WIN32 OR CYGWIN OR MINGW)
  endif()
 endif()
@@ -914,7 +805,7 @@ if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
   install(FILES libpng.3 libpngpf.3      DESTINATION ${PNG_MAN_DIR}/man3)
   install(FILES png.5                    DESTINATION ${PNG_MAN_DIR}/man5)
   # Install pkg-config files
-  if(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
+  if(NOT WIN32 OR CYGWIN OR MINGW)
     install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc
             DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
     install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
@@ -923,7 +814,7 @@ if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
             DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
     install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
             DESTINATION bin)
-  endif(NOT CMAKE_HOST_WIN32 OR CYGWIN OR MINGW)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
 endif()
 
 # On versions of CMake that support it, create an export file CMake
@@ -943,3 +834,4 @@ endif()
 # to create msvc import lib for mingw compiled shared lib
 # pexports libpng.dll > libpng.def
 # lib /def:libpng.def /machine:x86
+

INSTALL

@@ -16,11 +16,10 @@ Contents
       XI. Prepending a prefix to exported symbols
      XII. Configuring for compiler xxx:
     XIII. Removing unwanted object code
-     XIV. Enabling or disabling hardware optimizations
-      XV. Changes to the build and configuration of libpng in libpng-1.5.x
-     XVI. Setjmp/longjmp issues
-    XVII. Common linking failures
-   XVIII. Other sources of information about libpng
+     XIV. Changes to the build and configuration of libpng in libpng-1.5.x
+      XV. Setjmp/longjmp issues
+     XVI. Common linking failures
+    XVII. Other sources of information about libpng
 
 I. Simple installation
 
@@ -79,8 +78,8 @@ Or you can use one of the "projects" in the "projects" directory.
 
 Before installing libpng, you must first install zlib, if it
 is not already on your system.  zlib can usually be found
-wherever you got libpng; otherwise go to https://zlib.net/.  You can
-place zlib in the same directory as libpng or in another directory.
+wherever you got libpng; otherwise go to http://zlib.net.  You can place
+zlib in the same directory as libpng or in another directory.
 
 If your system already has a preinstalled zlib you will still need
 to have access to the zlib.h and zconf.h include files that
@@ -241,7 +240,8 @@ The files in libpng proper only include pngpriv.h and png.h, which
 in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h.
 As of libpng-1.5.0, pngpriv.h also includes three other private header
 files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
-that previously appeared in the public headers.
+that previously appeared in the public headers. As of libpng-1.7.0,
+pngchunk.h is also included, and is used privately by pngrutil.c.
 
 XIII. Removing unwanted object code
 
@@ -282,57 +282,7 @@ library to fail if they call functions not available in your library.
 The size of the library itself should not be an issue, because only
 those sections that are actually used will be loaded into memory.
 
-XIV. Enabling or disabling hardware optimizations
-
-Certain hardware capabilites, such as the Intel SSE instructions,
-are normally detected at run time. Enable them with configure options
-such as one of
-
-   --enable-arm-neon=yes
-   --enable-mips-msa=yes
-   --enable-intel-sse=yes
-   --enable-powerpc-vsx=yes
-
-or enable them all at once with
-
-   --enable-hardware-optimizations=yes
-
-or, if you are not using "configure", you can use one
-or more of
-
-   CPPFLAGS += "-DPNG_ARM_NEON"
-   CPPFLAGS += "-DPNG_MIPS_MSA"
-   CPPFLAGS += "-DPNG_INTEL_SSE"
-   CPPFLAGS += "-DPNG_POWERPC_VSX"
-
-See for example scripts/makefile.linux-opt
-
-If you wish to avoid using them,
-you can disable them via the configure option
-
-   --disable-hardware-optimizations
-
-to disable them all, or
-
-   --enable-intel-sse=no
-
-to disable a particular one,
-or via compiler-command options such as
-
-   CPPFLAGS += "-DPNG_ARM_NEON_OPT=0, -DPNG_MIPS_MSA_OPT=0,
-   -DPNG_INTEL_SSE_OPT=0, -DPNG_POWERPC_VSX_OPT=0"
-
-If you are using cmake, hardware optimizations are "on"
-by default. To disable them, use
-
-    cmake . -DPNG_ARM_NEON=no -DPNG_INTEL_SSE=no \
-            -DPNG_MIPS_MSA=no -DPNG_POWERPC_VSX=no
-
-or disable them all at once with
-
-    cmake . -DPNG_HARDWARE_OPTIMIZATIONS=no
-
-XV. Changes to the build and configuration of libpng in libpng-1.5.x
+XIV. Changes to the build and configuration of libpng in libpng-1.5.x
 
 Details of internal changes to the library code can be found in the CHANGES
 file and in the GIT repository logs.  These will be of no concern to the vast
@@ -423,7 +373,7 @@ $PREFIX/include directory).  Do not edit pnglibconf.h after you have built
 libpng, because than the settings would not accurately reflect the settings
 that were used to build libpng.
 
-XVI. Setjmp/longjmp issues
+XV. Setjmp/longjmp issues
 
 Libpng uses setjmp()/longjmp() for error handling.  Unfortunately setjmp()
 is known to be not thread-safe on some platforms and we don't know of
@@ -441,7 +391,7 @@ This requires setjmp/longjmp, so you must either build the library
 with PNG_SETJMP_SUPPORTED defined, or with PNG_SIMPLIFIED_READ_SUPPORTED
 and PNG_SIMPLIFIED_WRITE_SUPPORTED undefined.
 
-XVII. Common linking failures
+XVI. Common linking failures
 
 If your application fails to find libpng or zlib entries while linking:
 
@@ -453,7 +403,7 @@ If your application fails to find libpng or zlib entries while linking:
   If you are using the vstudio project, observe the WARNING in
   project/vstudio/README.txt.
 
-XVIII. Other sources of information about libpng:
+XVII. Other sources of information about libpng:
 
 Further information can be found in the README and libpng-manual.txt
 files, in the individual makefiles, in png.h, and the manual pages

LICENSE

@@ -10,7 +10,7 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000 through 1.6.32, August 24, 2017 are
+libpng versions 1.0.7, July 1, 2000 through 1.7.0beta90, August 28, 2017 are
 Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
@@ -22,9 +22,6 @@ added to the list of Contributing Authors:
    Cosmin Truta
    Gilles Vollant
    James Yu
-   Mandar Sahastrabuddhe
-   Google Inc.
-   Vadim Barkov
 
 and with the following additions to the disclaimer:
 
@@ -130,4 +127,4 @@ any encryption software.  See the EAR, paragraphs 734.3(b)(3) and
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-April 1, 2017
+August 28, 2017

Makefile.am

@@ -1,7 +1,7 @@
 # Makefile.am, the source file for Makefile.in (and hence Makefile), is
 #
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
-# Last changed in libpng 1.6.25 [September 1, 2016]
+# Last changed in libpng 1.7.0 [(PENDING RELEASE)]
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -12,7 +12,7 @@ PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 ACLOCAL_AMFLAGS = -I scripts
 
 # test programs - run on make check, make distcheck
-check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage pngcp
+check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage pngcp 
 if HAVE_CLOCK_GETTIME
 check_PROGRAMS += timepng
 endif
@@ -45,14 +45,14 @@ pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 pngimage_SOURCES = contrib/libtests/pngimage.c
 pngimage_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
-timepng_SOURCES = contrib/libtests/timepng.c
-timepng_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
 
+timepng_SOURCES = contrib/libtests/timepng.c
+timepng_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
 pngcp_SOURCES = contrib/tools/pngcp.c
 pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 
@@ -60,15 +60,14 @@ pngcp_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 # set of parameters:
 TESTS =\
    tests/pngtest\
-   tests/pngtest-badpngs\
    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-size\
+   tests/pngvalid-progressive-size tests/pngvalid-size\
    tests/pngvalid-progressive-interlace-standard\
-   tests/pngvalid-transform\
+   tests/pngvalid-transform tests/pngvalid-interlace-transform\
    tests/pngvalid-progressive-standard tests/pngvalid-standard\
    tests/pngstest-1.8 tests/pngstest-1.8-alpha tests/pngstest-linear\
    tests/pngstest-linear-alpha tests/pngstest-none tests/pngstest-none-alpha\
@@ -91,26 +90,15 @@ lib_LTLIBRARIES=libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
 	pngget.c pngmem.c pngpread.c pngread.c pngrio.c pngrtran.c pngrutil.c\
 	pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c\
-	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
+	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngchunk.h \
+	pngusr.dfa
 
-if PNG_ARM_NEON
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
-	arm/filter_neon.S arm/filter_neon_intrinsics.c
-endif
-
-if PNG_MIPS_MSA
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c\
-	mips/filter_msa_intrinsics.c
-endif
-
-if PNG_INTEL_SSE
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += intel/intel_init.c\
-	intel/filter_sse2_intrinsics.c
-endif
-
-if PNG_POWERPC_VSX
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += powerpc/powerpc_init.c\
-        powerpc/filter_vsx_intrinsics.c
+# Include libpng extensions, if appropriate.  This uses a Makefile.am fragment,
+# pre-set things that might be changed by addition:
+AM_CPPFLAGS =
+DFA_EXTENSION = 
+if LIBPNG_EXTENSIONS
+include $(top_srcdir)/contrib/extensions.am
 endif
 
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
@@ -153,12 +141,12 @@ EXTRA_DIST= \
 	$(TESTS) $(XFAIL_TESTS) tests/pngstest \
 	CMakeLists.txt example.c libpng-manual.txt
 
-SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk
+SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk scripts/pnglibconf.c
 
 CLEANFILES= *.tf? pngout.png libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc \
 	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config libpng.vers libpng.sym \
 	check.new pnglibconf.h pngprefix.h symbols.new pngtest-log.txt \
-	pnglibconf.out pnglibconf.c pnglibconf.pre pnglibconf.dfn \
+	pnglibconf.out pnglibconf.c pnglibconf.dfn pnglibconf.pre \
 	$(SCRIPT_CLEANFILES)
 
 MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess config.h.in \
@@ -170,8 +158,8 @@ config.sub configure depcomp install-sh ltmain.sh missing
 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
+# DFNCPP is normally just "CPP -E" - 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
 # parsing - and therefore fails with the .df files.  configure.ac has special
 # checks for this and sets DFNCPP appropriately.
@@ -190,6 +178,8 @@ 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
 
+pnglibconf.out: config.h
+
 libpng.sym: scripts/sym.out
 	rm -f $@
 	cp $? $@
@@ -201,7 +191,7 @@ 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
+pnglibconf.h: pnglibconf.out scripts/prefix.out scripts/macro.lst config.h
 	rm -f $@
 	$(AWK) 's==0 && NR>1{print prev}\
 	   s==0{prev=$$0}\
@@ -267,17 +257,17 @@ endif
 	rm -f $@ $*.tf[12]
 	test -d scripts || mkdir scripts || test -d scripts
 	$(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)\
-	    $(CPPFLAGS) $(SYMBOL_CFLAGS) $< > $*.tf1
+	    $(AM_CPPFLAGS) $(CPPFLAGS) $(SYMBOL_CFLAGS) $< > $*.tf1
 	$(AWK) -f "${srcdir}/scripts/dfn.awk" out="$*.tf2" $*.tf1 1>&2
 	rm -f $*.tf1
 	mv $*.tf2 $@
 
 # The .c file for pnglibconf.h is machine generated
-pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h pngusr.dfa $(DFA_XTRA)
+pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h pngusr.dfa $(DFA_EXTENSION) $(DFA_XTRA)
 	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
+	    $(DFA_EXTENSION) ${srcdir}/pngusr.dfa $(DFA_XTRA) 1>&2
 	$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf5 $*.tf4 1>&2
 	rm $*.tf4
 	mv $*.tf5 $@
@@ -295,8 +285,9 @@ scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.ou
 # be empty - no non-standard defines
 scripts/pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
 	rm -f $@ pnglibconf.tf[67]
-	test -z "$(CPPFLAGS)"
-	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
+	test -z "$(CPPFLAGS)" -a -z "$(AM_CPPFLAGS)"
+	(echo "com libpng @PNGLIB_VERSION@ STANDARD API DEFINITION";\
+	 echo "com") |\
 	$(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf6\
 	    logunsupported=1 version=search ${srcdir}/pngconf.h -\
 	    ${srcdir}/scripts/pnglibconf.dfa 1>&2
@@ -305,7 +296,7 @@ scripts/pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
 	rm pnglibconf.tf6
 	mv pnglibconf.tf7 $@
 
-$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS): png.h pngconf.h \
+$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS): png.h pngconf.h pngchunk.h \
 	pnglibconf.h pngpriv.h pngdebug.h pnginfo.h pngstruct.h pngprefix.h
 
 test: check-am

README

@@ -1,4 +1,4 @@
-README for libpng version 1.6.32 - August 24, 2017 (shared library 16.0)
+README for libpng version 1.7.0beta90 - August 28, 2017 (shared library 17.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
@@ -91,7 +91,7 @@ as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
 these at http://www.libpng.org/pub/png/pngdocs.html .
 
 This code is currently being archived at libpng.sourceforge.io in the
-[DOWNLOAD] area, and at http://libpng.download/src .  If you
+[DOWNLOAD] area, and at ftp://ftp-osl.osuosl.org/pub/libpng/src .  If you
 can't find it in any of those places, e-mail me, and I'll help you find it.
 
 I am not a lawyer, but I believe that the Export Control Classification
@@ -160,6 +160,7 @@ Files in this distribution:
       pngstruct.h   =>  png_struct declaration (private)
       pnginfo.h     =>  png_info struct declaration (private)
       pngdebug.h    =>  debugging macros (private)
+      pngchunk.h    =>  PNG chunk descriptions (private, new in libpng17)
       pngerror.c    =>  Error/warning message I/O functions
       pngget.c      =>  Functions for retrieving info from struct
       pngmem.c      =>  Memory handling functions
@@ -179,25 +180,18 @@ Files in this distribution:
       pngwtran.c    =>  Write data transformations
       pngwutil.c    =>  Write utility functions
       arm           =>  Contains optimized code for the ARM platform
-      powerpc       =>  Contains optimized code for the PowerPC platform
       contrib       =>  Contributions
-       arm-neon         =>  Optimized code for ARM-NEON platform
-       powerpc-vsx      =>  Optimized code for POWERPC-VSX platform
        examples         =>  Example programs
        gregbook         =>  source code for PNG reading and writing, from
                             Greg Roelofs' "PNG: The Definitive Guide",
                             O'Reilly, 1999
        libtests         =>  Test programs
-       mips-msa         =>  Optimized code for MIPS-MSA platform
        pngminim         =>  Minimal decoder, encoder, and progressive decoder
                             programs demonstrating use of pngusr.dfa
        pngminus         =>  Simple pnm2png and png2pnm programs
        pngsuite         =>  Test images
-       testpngs
        tools            =>  Various tools
        visupng          =>  Contains a MSVC workspace for VisualPng
-      intel             =>  Optimized code for INTEL-SSE2 platform
-      mips              =>  Optimized code for MIPS platform
       projects      =>  Contains project files and workspaces for
                         building a DLL
        owatcom          =>  Contains a WATCOM project for building libpng

TODO

@@ -26,5 +26,6 @@ Investigate pre-incremented loop counters and other loop constructions.
 Add interpolated method of handling interlacing.
 Extend pngvalid.c to validate more of the libpng transformations.
 Refactor preprocessor conditionals to compile entire statements
+Quiet compiler warnings (mostly -Wconversion warnings).
 
 */

configure.ac

@@ -1,12 +1,13 @@
 # configure.ac
 
 # Copyright (c) 2004-2016 Glenn Randers-Pehrson
-# Last changed in libpng 1.6.25 [September 1, 2016]
+# Last changed in libpng 1.7.0 [(PENDING RELEASE)]
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h
 
+
 dnl Process this file with autoconf to produce a configure script.
 dnl
 dnl Minor upgrades (compatible ABI): increment the package version
@@ -25,7 +26,7 @@ AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.32],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.7.0beta90],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -34,7 +35,8 @@ AC_CONFIG_MACRO_DIR([scripts])
 # dist-xz requires automake 1.11 or later
 # 1.12.2 fixes a security issue in 1.11.2 and 1.12.1
 # 1.13 is required for parallel tests
-AM_INIT_AUTOMAKE([1.13 foreign dist-xz color-tests silent-rules subdir-objects])
+# 1.14.1 is required for %reldir% support
+AM_INIT_AUTOMAKE([1.15 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
@@ -46,10 +48,10 @@ dnl automake, so the following is not necessary (and is not defined anyway):
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.6.32
+PNGLIB_VERSION=1.7.0beta90
 PNGLIB_MAJOR=1
-PNGLIB_MINOR=6
-PNGLIB_RELEASE=32
+PNGLIB_MINOR=7
+PNGLIB_RELEASE=0
 
 dnl End of version number stuff
 
@@ -67,10 +69,10 @@ 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 libtool/libtoolize; version 2.4.4 is the tested version, this or any
 dnl compatible later version may be used
 LT_INIT([win32-dll])
-LT_PREREQ([2.4.2])
+LT_PREREQ([2.4.4])
 
 # Some awks crash when confronted with pnglibconf.dfa, do a test run now
 # to make sure this doesn't happen
@@ -86,7 +88,7 @@ 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="$CPP"
+DFNCPP="$CPP -E"
 AC_SUBST(DFNCPP)
 
 # -Werror cannot be passed to GCC in CFLAGS because configure will fail (it
@@ -114,57 +116,153 @@ AC_ARG_ENABLE(werror,
       CFLAGS="$sav_CFLAGS"
     fi],)
 
-# For GCC 5 the default mode for C is -std=gnu11 instead of -std=gnu89
-# In pngpriv.h we request just the POSIX 1003.1 and C89 APIs by defining _POSIX_SOURCE to 1
-# This is incompatible with the new default mode, so we test for that and force the 
-# "-std=c89" compiler option:
-AC_MSG_CHECKING([if we need to force back C standard to C89])
-AC_COMPILE_IFELSE(
-   [AC_LANG_PROGRAM([
-      [#define _POSIX_SOURCE 1]
-      [#include <stdio.h>]
-   ])],
-   AC_MSG_RESULT(no),[
-      if test "x$GCC" != "xyes"; then
-         AC_MSG_ERROR(
-            [Forcing back to C89 is required but the flags are only known for GCC])
-      fi
-   AC_MSG_RESULT(yes)
-   CFLAGS="$CFLAGS -std=c89"
-])
-
 # Checks for header files.
 AC_HEADER_STDC
+# Headers used in pngpriv.h:
+AC_CHECK_HEADERS([assert.h stdlib.h string.h float.h fp.h math.h m68881.h])
+# Additional headers used in pngconf.h:
+AC_CHECK_HEADERS([limits.h stddef.h stdio.h setjmp.h time.h])
+# Used by pngread.c (for the simplified API):
+AC_CHECK_HEADERS([errno.h])
+# The following are not required for the standard 'make' build of libpng:
+# Additional requirements of contrib/libtests/makepng.c:
+AC_CHECK_HEADERS([ctype.h])
+# Additional requirements of contrib/libtests/pngvalid.c:
+AC_CHECK_HEADERS([fenv.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
-AC_C_CONST
-AC_TYPE_SIZE_T
-AC_STRUCT_TM
+# Most of these have been removed from 1.7.0 because they checked for non-ANSI-C
+# behaviors and the result were, anyway, not used by earlier versions of libpng.
 AC_C_RESTRICT
 
-# Checks for library functions.
-AC_FUNC_STRTOD
-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)) )
+# Checks for library functions; these need to be in order, least demanding to
+# most because the -l directives are added to the head of the list at each
+# check.
+# ANSI-C functions: all are required but they don't have to be implemented in
+# libc, it is perfectly ok to configure with an extra, wrapper, library preset
+# in LIBS.  NOTE: this list may not be complete
+AC_CHECK_FUNCS([memset memcpy strncpy],,
+               AC_MSG_FAILURE([missing ANSI-C functions]))
 
 # Some later POSIX 1003.1 functions are required for test programs, failure here
 # is soft (the corresponding test program is not built).
 AC_CHECK_FUNC([clock_gettime],,[AC_MSG_WARN([not building timepng])])
 AM_CONDITIONAL([HAVE_CLOCK_GETTIME], [test "$ac_cv_func_clock_gettime" = "yes"])
 
-AC_ARG_WITH(zlib-prefix,
-   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, ${ZPREFIX}zlibVersion, , AC_MSG_ERROR(zlib not installed)))
+# floor and ceil are required for FLOATING_POINT, but they can be turned off on
+# the configure command line (and they are independent.)  Default is to 'on'
+AC_ARG_ENABLE([floating-point],
+   AS_HELP_STRING([[[--enabled-floating-point]]],
+      [Enable floating point APIs (default: yes)]),,
+   [enable_floating_point=yes])
+
+AC_ARG_ENABLE([fixed-point],
+   AS_HELP_STRING([[[--enable-fixed-point]]],
+      [Enable fixed point APIs (default: yes)]),,
+   [enable_fixed_point=yes])
+
+AC_ARG_ENABLE([floating-arithmetic],
+   AS_HELP_STRING([[[--enable-floating-arithmetic]]],
+      [Use floating point arithmetic internally (default: yes)]),,
+   [enable_floating_arithmetic=yes])
+
+# Check for a requirement for math library support
+if test "$enable_floating_arithmetic" = yes
+then
+   AC_SEARCH_LIBS([floor],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+   AC_SEARCH_LIBS([frexp],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+   AC_SEARCH_LIBS([modf],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+   AC_SEARCH_LIBS([atof],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+   AC_SEARCH_LIBS([pow],[m],,
+                  [AC_MSG_WARN([not found])
+                   enable_floating_arithmetic=no])
+fi
+
+# Set the relevant defines if required (only if required). This will override
+# anything on the command line.
+if test "$enable_floating_point" != yes
+then
+   AC_MSG_NOTICE([Floating point APIs disabled])
+   AC_DEFINE([PNG_NO_FLOATING_POINT],[1],
+             [No support for floating point APIs])
+fi
+if test "$enable_fixed_point" != yes
+then
+   AC_MSG_NOTICE([Fixed point APIs disabled])
+   AC_DEFINE([PNG_NO_FIXED_POINT],[1],
+             [No support for fixed point APIs])
+fi
+if test "$enable_floating_arithmetic" != yes
+then
+   AC_MSG_NOTICE([Fixed point arithmetic will be used])
+   AC_DEFINE([PNG_NO_FLOATING_ARITHMETIC],[1],
+             [No support for floating point arithmetic])
+fi
 
 # 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
 # library (typically), it's not an error if it is not found.
-AC_CHECK_LIB([m], [feenableexcept])
-AC_CHECK_FUNCS([feenableexcept])
+AC_SEARCH_LIBS([feenableexcept],[m],AC_DEFINE([HAVE_FEENABLEEXCEPT],[1],
+      [Define to 1 if the feenableexcept function is available]))
+# Required by pngvalid:
+AC_SEARCH_LIBS([ceil],[m])
+
+# zlib checks and arguments;
+#  package zlib: argument is the name of the library
+#  zlib-header: the name of the header file
+#  zlib-prefix: the prefix for library functions, if any
+AC_ARG_WITH([zlib],
+   AS_HELP_STRING([[[--with-zlib=<name>]]],
+                  [base name of the zlib implementation (e.g. 'z')]),,
+   [with_zlib='z'])
+
+z_prefix=
+AC_ARG_WITH([zlib-prefix],
+   AS_HELP_STRING([[[--with-zlib-prefix=<prefix>]]],
+                  [prefix for zlib API functions]),
+   [if test "$withval" = "" -o "$withval" = yes; then
+      with_zlib_prefix='z_'
+      AC_DEFINE([PNG_ZLIB_PREFIX],[z_],[Standard zlib prefix])
+   elif test "${withval}" != "no"; then
+      AC_DEFINE_UNQUOTED([PNG_ZLIB_PREFIX],[${withval}],
+         [User defined zlib prefix])
+   else
+      with_zlib_prefix=
+   fi
+   if test "$with_zlib_prefix" != ""; then
+      AC_DEFINE([Z_PREFIX],[1],[Tell zlib.h to prefix function names])
+      z_prefix="#define Z_PREFIX 1"
+   fi])
+
+AC_ARG_WITH([zlib-header],
+   AS_HELP_STRING([[[--with-zlib-header='<file>' or '"file"']]],
+      [C include argument to locate zlib header file, e.g. <zlib.h>, take
+       care to put single quotes round this on the command line]),
+   [AC_DEFINE_UNQUOTED([PNG_ZLIB_HEADER],[${withval}],[Zlib header file])],
+   with_zlib_header='<zlib.h>')
+
+# AC_CHECK_LIB isn't quite enough for this because we need the special header
+# file too.
+LIBS="-l${with_zlib} $LIBS"
+AC_MSG_CHECKING(
+   [[Library '${with_zlib}' and #include ${with_zlib_header} for symbol '${with_zlib_prefix}zlibVersion']])
+AC_LINK_IFELSE(
+   [AC_LANG_PROGRAM(
+      [[
+${z_prefix}
+#include ${with_zlib_header}
+      ]],
+      [[(void)${with_zlib_prefix}zlibVersion();]])],
+   AC_MSG_RESULT([ok]),
+   AC_MSG_FAILURE([not found]))
 
 AC_MSG_CHECKING([if using Solaris linker])
 SLD=`$LD --version 2>&1 | grep Solaris`
@@ -210,7 +308,7 @@ AM_CONDITIONAL(HAVE_LD_VERSION_SCRIPT, test "$have_ld_version_script" = "yes")
 if test "$have_ld_version_script" = "yes"; then
     AC_MSG_CHECKING([for symbol prefix])
     SYMBOL_PREFIX=`echo "PREFIX=__USER_LABEL_PREFIX__" \
-                  | ${CPP-${CC-gcc} -E} - 2>&1 \
+                  | ${DFNCPP-${CC-gcc -E}} - 2>&1 \
                   | ${EGREP-grep} "^PREFIX=" \
                   | ${SED-sed} -e "s:^PREFIX=::" -e "s:__USER_LABEL_PREFIX__::"`
     AC_SUBST(SYMBOL_PREFIX)
@@ -297,237 +395,16 @@ AC_ARG_ENABLE([unversioned-libpng-config],
 AM_CONDITIONAL([DO_INSTALL_LIBPNG_CONFIG],
    [test "$enable_unversioned_libpng_config" != "no"])
 
-# HOST SPECIFIC OPTIONS
-# =====================
-#
-# DEFAULT
-# =======
-#
-AC_ARG_ENABLE([hardware-optimizations],
-   AS_HELP_STRING([[[--enable-hardware-optimizations]]],
-      [Enable hardware optimizations: =no/off, yes/on:]),
-   [case "$enableval" in
-      no|off)
-         # disable hardware optimization on all systems:
-         enable_arm_neon=no
-         AC_DEFINE([PNG_ARM_NEON_OPT], [0],
-           [Disable ARM_NEON optimizations])
-         enable_mips_msa=no
-         AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
-           [Disable MIPS_MSA optimizations])
-         enable_powerpc_vsx=no
-         AC_DEFINE([PNG_POWERPC_VSX_OPT], [0],
-           [Disable POWERPC VSX optimizations])
-         enable_intel_sse=no
-         AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
-           [Disable INTEL_SSE optimizations])
-         ;;
-      *)
-         # allow enabling hardware optimization on any system:
-         case "$host_cpu" in
-            arm*|aarch64*)
-              enable_arm_neon=yes
-              AC_DEFINE([PNG_ARM_NEON_OPT], [0],
-                [Enable ARM_NEON optimizations])
-              ;;
-            mipsel*|mips64el*)
-              enable_mips_msa=yes
-              AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
-                [Enable MIPS_MSA optimizations])
-              ;;
-            i?86|x86_64)
-              enable_intel_sse=yes
-              AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
-                [Enable Intel SSE optimizations])
-              ;;
-            powerpc*|ppc64*)
-              enable_powerpc_vsx=yes
-              AC_DEFINE([PNG_POWERPC_VSX_OPT], [2],
-                [Enable POWERPC VSX optimizations])
-              ;;
-         esac
-         ;;
-   esac])
-
-# ARM
-# ===
-#
-# ARM NEON (SIMD) support.
-
-AC_ARG_ENABLE([arm-neon],
-   AS_HELP_STRING([[[--enable-arm-neon]]],
-      [Enable ARM NEON optimizations: =no/off, check, api, yes/on:]
-      [no/off: disable the optimizations; check: use internal checking code]
-      [(deprecated and poorly supported); api: disable by default, enable by]
-      [a call to png_set_option; yes/on: turn on unconditionally.]
-      [If not specified: determined by the compiler.]),
-   [case "$enableval" in
-      no|off)
-         # disable the default enabling on __ARM_NEON__ systems:
-         AC_DEFINE([PNG_ARM_NEON_OPT], [0],
-                   [Disable ARM Neon optimizations])
-         # Prevent inclusion of the assembler files below:
-         enable_arm_neon=no;;
-      check)
-         AC_DEFINE([PNG_ARM_NEON_CHECK_SUPPORTED], [],
-                   [Check for ARM Neon support at run-time]);;
-      api)
-         AC_DEFINE([PNG_ARM_NEON_API_SUPPORTED], [],
-                   [Turn on ARM Neon optimizations at run-time]);;
-      yes|on)
-         AC_DEFINE([PNG_ARM_NEON_OPT], [2],
-                   [Enable ARM Neon optimizations])
-         AC_MSG_WARN([--enable-arm-neon: please specify 'check' or 'api', if]
-            [you want the optimizations unconditionally pass -mfpu=neon]
-            [to the compiler.]);;
-      *)
-         AC_MSG_ERROR([--enable-arm-neon=${enable_arm_neon}: invalid value])
-   esac])
-
-# Add ARM specific files to all builds where the host_cpu is arm ('arm*') or
-# where ARM optimizations were explicitly requested (this allows a fallback if a
-# future host CPU does not match 'arm*')
-
-AM_CONDITIONAL([PNG_ARM_NEON],
-   [test "$enable_arm_neon" != 'no' &&
-    case "$host_cpu" in
-      arm*|aarch64*) :;;
-      *)    test "$enable_arm_neon" != '';;
-    esac])
-
-# MIPS
-# ===
-#
-# MIPS MSA (SIMD) support.
-
-AC_ARG_ENABLE([mips-msa],
-   AS_HELP_STRING([[[--enable-mips-msa]]],
-      [Enable MIPS MSA optimizations: =no/off, check, api, yes/on:]
-      [no/off: disable the optimizations; check: use internal checking code]
-      [(deprecated and poorly supported); api: disable by default, enable by]
-      [a call to png_set_option; yes/on: turn on unconditionally.]
-      [If not specified: determined by the compiler.]),
-   [case "$enableval" in
-      no|off)
-         # disable the default enabling on __mips_msa systems:
-         AC_DEFINE([PNG_MIPS_MSA_OPT], [0],
-                   [Disable MIPS MSA optimizations])
-         # Prevent inclusion of the assembler files below:
-         enable_mips_msa=no;;
-      check)
-         AC_DEFINE([PNG_MIPS_MSA_CHECK_SUPPORTED], [],
-                   [Check for MIPS MSA support at run-time]);;
-      api)
-         AC_DEFINE([PNG_MIPS_MSA_API_SUPPORTED], [],
-                   [Turn on MIPS MSA optimizations at run-time]);;
-      yes|on)
-         AC_DEFINE([PNG_MIPS_MSA_OPT], [2],
-                   [Enable MIPS MSA optimizations])
-         AC_MSG_WARN([--enable-mips-msa: please specify 'check' or 'api', if]
-            [you want the optimizations unconditionally pass '-mmsa -mfp64']
-            [to the compiler.]);;
-      *)
-         AC_MSG_ERROR([--enable-mips-msa=${enable_mips_msa}: invalid value])
-   esac])
-
-# Add MIPS specific files to all builds where the host_cpu is mips ('mips*') or
-# where MIPS optimizations were explicitly requested (this allows a fallback if a
-# future host CPU does not match 'mips*')
-
-AM_CONDITIONAL([PNG_MIPS_MSA],
-   [test "$enable_mips_msa" != 'no' &&
-    case "$host_cpu" in
-      mipsel*|mips64el*) :;;
-    esac])
-
-# INTEL
-# =====
-#
-# INTEL SSE (SIMD) support.
-
-AC_ARG_ENABLE([intel-sse],
-   AS_HELP_STRING([[[--enable-intel-sse]]],
-      [Enable Intel SSE optimizations: =no/off, yes/on:]
-      [no/off: disable the optimizations;]
-      [yes/on: enable the optimizations.]
-      [If not specified: determined by the compiler.]),
-   [case "$enableval" in
-      no|off)
-         # disable the default enabling:
-         AC_DEFINE([PNG_INTEL_SSE_OPT], [0],
-                   [Disable Intel SSE optimizations])
-         # Prevent inclusion of the assembler files below:
-         enable_intel_sse=no;;
-      yes|on)
-         AC_DEFINE([PNG_INTEL_SSE_OPT], [1],
-                   [Enable Intel SSE optimizations]);;
-      *)
-         AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}: invalid value])
-   esac])
-
-# Add Intel specific files to all builds where the host_cpu is Intel ('x86*')
-# or where Intel optimizations were explicitly requested (this allows a
-# fallback if a future host CPU does not match 'x86*')
-AM_CONDITIONAL([PNG_INTEL_SSE],
-   [test "$enable_intel_sse" != 'no' &&
-    case "$host_cpu" in
-      i?86|x86_64) :;;
-      *)    test "$enable_intel_sse" != '';;
-    esac])
-
-# PowerPC
-# ===
-#
-# PowerPC VSX (SIMD) support.
-
-AC_ARG_ENABLE([powerpc-vsx],
-AS_HELP_STRING([[[--enable-powerpc-vsx]]],
-      [Enable POWERPC VSX optimizations: =no/off, check, api, yes/on:]
-      [no/off: disable the optimizations; check: use internal checking code]
-      [api: disable by default, enable by a call to png_set_option]
-      [yes/on: turn on unconditionally.]
-      [If not specified: determined by the compiler.]),
-   [case "$enableval" in
-      no|off)
-         # disable the default enabling on __ppc64__ systems:
-         AC_DEFINE([PNG_POWERPC_VSX_OPT], [0],
-                   [Disable POWERPC VSX optimizations])
-         # Prevent inclusion of the platform specific files below:
-         enable_powerpc_vsx=no;;
-      check)
-         AC_DEFINE([PNG_POWERPC_VSX_CHECK_SUPPORTED], [],
-                   [Check for POWERPC VSX support at run-time])
-         AC_MSG_WARN([--enable-powerpc-vsx Please check contrib/powerpc/README file]
-            [for the list of supported OSes.]);;
-      api)
-         AC_DEFINE([PNG_POWERPC_VSX_API_SUPPORTED], [],
-                   [Turn on POWERPC VSX optimizations at run-time]);;
-      yes|on)
-         AC_DEFINE([PNG_POWERPC_VSX_OPT], [2],
-                   [Enable POWERPC VSX optimizations])
-         AC_MSG_WARN([--enable-powerpc-vsx: please specify 'check' or 'api', if]
-            [you want the optimizations unconditionally pass '-maltivec -mvsx']
-            [or '-mcpu=power8'to the compiler.]);;
-      *)
-         AC_MSG_ERROR([--enable-powerpc-vsx=${enable_powerpc_vsx}: invalid value])
-   esac])
-
-# Add PowerPC specific files to all builds where the host_cpu is powerpc('powerpc*') or
-# where POWERPC optimizations were explicitly requested (this allows a fallback if a
-# future host CPU does not match 'powerpc*')
-
-AM_CONDITIONAL([PNG_POWERPC_VSX],
-   [test "$enable_powerpc_vsx" != 'no' &&
-    case "$host_cpu" in
-      powerpc*|ppc64*) :;;
-    esac])
-
+# EXTENSIONS
+# Configure (and all other) support for extensions is included when autoconf is
+# run by virtue of the existence (or not) of the following file:
+sinclude([contrib/extensions.ac])
+AM_CONDITIONAL([LIBPNG_EXTENSIONS],[test -n "$libpng_automake_extensions"])
 
 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])
+AC_CONFIG_FILES([Makefile libpng.pc])
+AC_CONFIG_FILES([libpng-config], [chmod +x libpng-config])
 
 AC_OUTPUT

contrib/arm-neon/linux.c

@@ -1,8 +1,8 @@
 /* contrib/arm-neon/linux.c
  *
- * Last changed in libpng 1.6.31 [July 27, 2017]
- * Copyright (c) 2014, 2017 Glenn Randers-Pehrson
- * Written by John Bowler, 2014, 2017.
+ * Copyright (c) 2014 Glenn Randers-Pehrson
+ * Written by John Bowler, 2014.
+ * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -62,7 +62,7 @@ png_have_neon(png_structp png_ptr)
 
                counter=0;
                state = Feature;
-               /* FALLTHROUGH */
+               /* FALL THROUGH */
 
             case Feature:
                /* Match 'FEATURE', ASCII case insensitive. */
@@ -75,7 +75,7 @@ png_have_neon(png_structp png_ptr)
 
                /* did not match 'feature' */
                state = SkipLine;
-               /* FALLTHROUGH */
+               /* FALL THROUGH */
 
             case SkipLine:
             skipLine:
@@ -110,7 +110,7 @@ png_have_neon(png_structp png_ptr)
 
                state = Neon;
                counter = 0;
-               /* FALLTHROUGH */
+               /* FALL THROUGH */
 
             case Neon:
                /* Look for 'neon' tag */
@@ -122,7 +122,7 @@ png_have_neon(png_structp png_ptr)
                }
 
                state = SkipTag;
-               /* FALLTHROUGH */
+               /* FALL THROUGH */
 
             case SkipTag:
                /* Skip non-space characters */

contrib/conftest/pngcp.dfa

@@ -13,30 +13,15 @@
 #
 everything = off
 
-# This option is specific to this configuration; it adds a #define to the
-# generated pnglibconf.h which turns on the (not portable) timing option for
-# pngcp.  Note that any option is automatically preceded by PNG_; there is no
-# way round this and this is deliberate.
-option PNGCP_TIMING
-
-# Because of the everything off above the option must also be turned on.  This
-# may not be done in one step because it is safer and avoids mis-spelled options
-# in user .dfa files to error out if an unrecognized option is turned on.
-option PNGCP_TIMING on
-
 # Options to turn on png_read_png and png_write_png:
-option INFO_IMAGE on
-option SEQUENTIAL_READ on
+option WRITE_PNG on
+option READ_PNG on
 option EASY_ACCESS on
-option WRITE on
 option WRITE_16BIT on
-option WRITE_FILTER on
+option SELECT_FILTER on
 
 # pngcp needs this to preserve unknown chunks, switching all these on means that
 # pngcp can work without explicit known chunk reading suppport
-option UNKNOWN_CHUNKS on
-option SET_UNKNOWN_CHUNKS on
-option HANDLE_AS_UNKNOWN on
 option SAVE_UNKNOWN_CHUNKS on
 option WRITE_UNKNOWN_CHUNKS on
 
@@ -44,10 +29,6 @@ option WRITE_UNKNOWN_CHUNKS on
 option CHECK_FOR_INVALID_INDEX on
 option GET_PALETTE_MAX on
 
-# Pre-libpng 1.7 pngcp has to stash text chunks manually, post 1.7 without this
-# text chunks should be handled as unknown ok.
-option TEXT on
-
 # this is used to turn off limits:
 option USER_LIMITS on
 option SET_USER_LIMITS on

contrib/examples/README.txt

@@ -21,4 +21,4 @@ ORIGINAL AUTHORS
     of the people below claim any rights with regard to the contents of this
     directory.
 
-    John Bowler <jbowler at acm.org>
+    John Bowler <jbowler@acm.org>

contrib/examples/pngtopng.c

@@ -5,7 +5,7 @@
  * related or neighboring rights to this work.  This work is published from:
  * United States.
  *
- * Last changed in libpng 1.6.29 [March 16, 2017]
+ * Last changed in libpng 1.6.29 [%RDATE%]
  *
  * Read a PNG and write it out in a fixed format, using the 'simplified API'
  * that was introduced in libpng-1.6.0.

contrib/extensions.ac

@@ -0,0 +1,16 @@
+# CONTRIBUTED EXTENSIONS
+#
+# The following extensions are part of a standard libpng distribution.  They are
+# not supported parts of libpng and they are not necessarily released under the
+# same license as libpng.  Please consult the relevant directory for copyright
+# and support information before uncommenting any of the lines below.
+#
+# After you change this file you MUST re-run "autoreconf" to regenerate the
+# configure script, otherwise the change may have no effect.
+#
+# Include the ARM NEON extension:
+#sinclude([contrib/neon/neon.ac])
+#
+# If any of the extensions require automake support (this is likely) automake
+# must include the file contrib/extensions.am
+#libpng_automake_extensions="yes"

contrib/extensions.am

@@ -0,0 +1,7 @@
+# CONTRIBUTED EXTENSIONS
+#
+# Please read the file "contrib/extensions.ac" before making changes to this
+# file.
+#
+# Include the ARM NEON extension:
+#include %reldir%/neon/neon.am

contrib/gregbook/Makefile.sgi

@@ -23,9 +23,9 @@
 
 # macros --------------------------------------------------------------------
 
-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
+PNGINC = -I/usr/local/include/libpng17
+PNGLIB = -L/usr/local/lib -lpng17	  # dynamically linked against libpng
+#PNGLIB = /usr/local/lib/libpng17.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/libpng16
-#PNGLIBd = -L$(PNGDIR) -lpng16 # dynamically linked, installed libpng
-#PNGLIBs = $(PNGDIR)/libpng16.a # statically linked, installed libpng
+#PNGINC = -I/usr/local/include/libpng17
+#PNGLIBd = -L$(PNGDIR) -lpng17 # dynamically linked, installed libpng
+#PNGLIBs = $(PNGDIR)/libpng17.a # statically linked, installed libpng
 # or:
 PNGDIR = ../..#	this one is for libpng-x.y.z/contrib/gregbook builds
 #PNGDIR = ../libpng
 PNGINC = -I$(PNGDIR)
-PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng16	# dynamically linked
+PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng17	# dynamically linked
 PNGLIBs = $(PNGDIR)/libpng.a		# statically linked, local libpng
 
 ZDIR = /usr/local/lib
@@ -59,16 +59,15 @@ INCS = $(PNGINC) $(ZINC) $(XINC)
 RLIBSd = $(PNGLIBd) $(ZLIBd) $(XLIB) -lm
 RLIBSs = $(PNGLIBs) $(ZLIBs) $(XLIB) -lm
 WLIBSd = $(PNGLIBd) $(ZLIBd) -lm
-WLIBSs = $(PNGLIBs) $(ZLIBs) -lm
+WLIBSs = $(PNGLIBs) $(ZLIBs)
 
 CC = gcc
 LD = gcc
 RM = rm -f
 CPPFLAGS = $(INCS) -DFEATURE_LOOP
 CFLAGS = -O -Wall
-#CFLAGS = -O -W -Wall -Wextra -pedantic -ansi
 # [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
-# [-ansi, -pedantic, -Wextra, and -W can also be used]
+# [-ansi, -pedantic and -W can also be used]
 LDFLAGS =
 O = .o
 E =

contrib/gregbook/README

@@ -15,7 +15,7 @@ of PBMPLUS/NetPBM) and converts them to PNG.
 
 The source code for all three demo programs currently compiles under
 Unix, OpenVMS, and 32-bit Windows.  (Special thanks to Martin Zinser,
-zinser at decus.de, for making the necessary changes for OpenVMS and for
+zinser@decus.de, for making the necessary changes for OpenVMS and for
 providing an appropriate build script.)  Build instructions can be found
 below.
 

contrib/gregbook/readpng.c

@@ -4,7 +4,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007,2017 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -100,8 +100,7 @@ int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
 
     /* could pass pointers to user-defined error handlers instead of NULLs: */
 
-    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), NULL, NULL,
-        NULL);
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
     if (!png_ptr)
         return 4;   /* out of memory */
 
@@ -264,12 +263,6 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
     *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
     *pChannels = (int)png_get_channels(png_ptr, info_ptr);
 
-    /* Guard against integer overflow */
-    if (height > ((size_t)(-1))/rowbytes) {
-        fprintf(stderr, "readpng:  image_data buffer would be too large\n",
-        return NULL;
-    }
-
     if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
         png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
         return NULL;

contrib/gregbook/readpng2.c

@@ -54,8 +54,7 @@
   ---------------------------------------------------------------------------
 
    Changelog:
-     2015-11-12 - Check return value of png_get_bKGD() (Glenn R-P)
-     2017-04-22 - Guard against integer overflow (Glenn R-P)
+     %RDATE% - Check return value of png_get_bKGD() (Glenn R-P)
 
   ---------------------------------------------------------------------------*/
 

contrib/gregbook/readppm.c

@@ -9,7 +9,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007,2017 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -154,18 +154,13 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
     *pRowbytes = rowbytes = channels*width;
     *pChannels = channels;
 
-    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
-
-    /* Guard against integer overflow */
-    if (height > ((size_t)(-1))/rowbytes) {
-        fprintf(stderr, PROGNAME ":  image_data buffer would be too large\n",
-        return NULL;
-    }
-
     if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
         return NULL;
     }
 
+    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
+
+
     /* now we can go ahead and just read the whole image */
 
     if (fread(image_data, 1L, rowbytes*height, saved_infile) <

contrib/gregbook/rpng-win.c

@@ -24,11 +24,10 @@
     - 1.10:  enabled "message window"/console (thanks to David Geldreich)
     - 2.00:  dual-licensed (added GNU GPL)
     - 2.01:  fixed improper display of usage screen on PNG error(s)
-    - 2.02:  check for integer overflow (Glenn R-P)
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2008, 2017 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -183,7 +182,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
 #ifndef __CYGWIN__
     /* First reenable console output, which normally goes to the bit bucket
      * for windowed apps.  Closing the console window will terminate the
-     * app.  Thanks to David.Geldreich at realviz.com for supplying the magical
+     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
      * incantation. */
 
     AllocConsole();
@@ -497,12 +496,6 @@ static int rpng_win_create_window(HINSTANCE hInst, int showmode)
 
     wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2;
 
-    /* Guard against integer overflow */
-    if (image_height > ((size_t)(-1))/wimage_rowbytes) {
-        fprintf(stderr, PROGNAME ":  image_data buffer would be too large\n");
-        return 4;   /* fail */
-    }
-
     if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
                               wimage_rowbytes*image_height)))
     {

contrib/gregbook/rpng-x.c

@@ -26,13 +26,10 @@
     - 1.14:  added support for X resources (thanks to Gerhard Niklasch)
     - 2.00:  dual-licensed (added GNU GPL)
     - 2.01:  fixed improper display of usage screen on PNG error(s)
-    - 2.02:  Added "void(argc);" statement to quiet pedantic compiler warnings
-             about unused variable (GR-P)
-    - 2.03:  check for integer overflow (Glenn R-P)
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2008, 2017 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -83,7 +80,7 @@
 
 #define PROGNAME  "rpng-x"
 #define LONGNAME  "Simple PNG Viewer for X"
-#define VERSION   "2.02 of 15 June 2014"
+#define VERSION   "2.01 of 16 March 2008"
 #define RESNAME   "rpng"        /* our X resource application name */
 #define RESCLASS  "Rpng"        /* our X resource class name */
 
@@ -282,17 +279,15 @@ int main(int argc, char **argv)
           "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
           "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
           "    exp \ttransfer-function exponent (``gamma'') of the display\n"
-          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n",
-          PROGNAME, default_display_exponent);
-
-        fprintf(stderr, "\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
           "\t\t  to the product of the lookup-table exponent (varies)\n"
           "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
           "    bg  \tdesired background color in 7-character hex RGB format\n"
           "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
           "\t\t  used with transparent images\n"
           "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
-          "is displayed) to quit.\n");
+          "is displayed) to quit.\n"
+          "\n", PROGNAME, default_display_exponent);
         exit(1);
     }
 
@@ -424,8 +419,6 @@ int main(int argc, char **argv)
 
     rpng_x_cleanup();
 
-    (void)argc; /* Unused */
-
     return 0;
 }
 

contrib/gregbook/rpng2-win.c

@@ -33,11 +33,10 @@
     - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
               unexpected-EOF and file-read-error cases
     - 2.03:  removed runtime MMX-enabling/disabling and obsolete -mmx* options
-    - 2.04:  check for integer overflow (Glenn R-P)
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2008, 2017 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -300,7 +299,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
 #ifndef __CYGWIN__
     /* Next reenable console output, which normally goes to the bit bucket
      * for windowed apps.  Closing the console window will terminate the
-     * app.  Thanks to David.Geldreich at realviz.com for supplying the magical
+     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
      * incantation. */
 
     AllocConsole();
@@ -649,13 +648,6 @@ static void rpng2_win_init()
     Trace((stderr, "  width  = %ld\n", rpng2_info.width))
     Trace((stderr, "  height = %ld\n", rpng2_info.height))
 
-    /* Guard against integer overflow */
-    if (rpng2_info.height > ((size_t)(-1))/rowbytes) {
-        fprintf(stderr, PROGNAME ":  image_data buffer would be too large\n",
-        readpng2_cleanup(&rpng2_info);
-        return;
-    }
-
     rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height);
     if (!rpng2_info.image_data) {
         readpng2_cleanup(&rpng2_info);

contrib/gregbook/rpng2-x.c

@@ -44,11 +44,9 @@
     - 2.04:  Added "void(foo);" statements to quiet pedantic compiler warnings
              about unused variables (GR-P)
     - 2.05:  Use nanosleep() instead of usleep(), which is deprecated (GR-P).
-    - 2.06:  check for integer overflow (Glenn R-P)
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2010, 2014-2015, 2017 Greg Roelofs.  All rights
-      reserved.
+      Copyright (c) 1998-2010, 2014-2015 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -782,13 +780,6 @@ static void rpng2_x_init(void)
     Trace((stderr, "  width  = %ld\n", rpng2_info.width))
     Trace((stderr, "  height = %ld\n", rpng2_info.height))
 
-    /* Guard against integer overflow */
-    if (rpng2_info.height > ((size_t)(-1))/rpng2_info.rowbytes) {
-        fprintf(stderr, PROGNAME ":  image_data buffer would be too large\n");
-        readpng2_cleanup(&rpng2_info);
-        return;
-    }
-
     rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height);
     if (!rpng2_info.image_data) {
         readpng2_cleanup(&rpng2_info);

contrib/gregbook/wpng.c

@@ -29,7 +29,6 @@
     - 1.04:  fixed DOS/OS2/Win32 detection, including partial Cygwin fix
               (see http://home.att.net/~perlspinr/diffs/GregBook_cygwin.diff)
     - 2.00:  dual-licensed (added GNU GPL)
-    - 2.01:  check for integer overflow (Glenn R-P)
 
         [REPORTED BUG (win32 only):  "contrib/gregbook/wpng.c - cmd line
          dose not work!  In order to do something useful I needed to redirect
@@ -39,7 +38,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007, 2017 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -703,18 +702,7 @@ int main(int argc, char **argv)
     if (wpng_info.interlaced) {
         long i;
         ulg bytes;
-        ulg image_bytes;
-
-        /* Guard against integer overflow */
-        if (wpng_info_height > ((size_t)(-1)/rowbytes ||
-            wpng_info_height > ((ulg)(-1)/rowbytes) {
-            fprintf(stderr, PROGNAME ":  image_data buffer too large\n");
-            writepng_cleanup(&wpng_info);
-            wpng_cleanup();
-            exit(5);
-        }
-
-        image_bytes = rowbytes * wpng_info.height;
+        ulg image_bytes = rowbytes * wpng_info.height;   /* overflow? */
 
         wpng_info.image_data = (uch *)malloc(image_bytes);
         wpng_info.row_pointers = (uch **)malloc(wpng_info.height*sizeof(uch *));

contrib/gregbook/writepng.c

@@ -4,7 +4,7 @@
 
   ---------------------------------------------------------------------------
 
-      Copyright (c) 1998-2007, 2017 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
 
       This software is provided "as is," without warranty of any kind,
       express or implied.  In no event shall the author or contributors
@@ -90,7 +90,7 @@ int writepng_init(mainprog_info *mainprog_ptr)
 
     /* could also replace libpng warning-handler (final NULL), but no need: */
 
-    png_ptr = png_create_write_struct(png_get_libpng_ver(NULL), mainprog_ptr,
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
       writepng_error_handler, NULL);
     if (!png_ptr)
         return 4;   /* out of memory */

contrib/libtests/pngimage.c

@@ -2,7 +2,7 @@
  *
  * Copyright (c) 2015,2016 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.24 [August 4, 2016]
+ * Last changed in libpng 1.6.22 [May 26, 2016]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer

contrib/libtests/pngstest-errors.h

@@ -1,6 +1,6 @@
 /* contrib/libtests/pngstest-errors.h
  *
- * BUILT USING: libpng version 1.6.19beta03 - September 25, 2015
+ * BUILT USING: libpng version 1.7.0beta66 - September 18, 2015
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -22,7 +22,7 @@ static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] =
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
  }, { /* input: sRGB-gray+alpha */
-  { 0, 19, 0, 0 }, { 0, 0, 0, 0 }, { 0, 20, 0, 0 }, { 0, 0, 0, 0 },
+  { 0, 19, 1, 0 }, { 0, 0, 0, 0 }, { 0, 20, 1, 0 }, { 0, 0, 0, 0 },
   { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 },
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
@@ -32,8 +32,8 @@ static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] =
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
  }, { /* input: sRGB-rgb+alpha */
-  { 0, 16, 17, 0 }, { 0, 17, 17, 0 }, { 0, 19, 0, 0 }, { 0, 0, 0, 0 },
-  { 0, 850, 875, 0 }, { 0, 850, 875, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 },
+  { 0, 14, 13, 0 }, { 0, 15, 13, 0 }, { 0, 19, 1, 0 }, { 0, 0, 0, 0 },
+  { 0, 832, 764, 0 }, { 0, 832, 764, 0 }, { 0, 897, 788, 0 }, { 0, 897, 788, 0 },
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
  }, { /* input: linear-gray */
@@ -67,13 +67,13 @@ static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] =
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
  }, { /* input: color-mapped-sRGB-rgb */
-  { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
+  { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 8, 0 }, { 0, 0, 8, 0 },
   { 0, 0, 673, 0 }, { 0, 0, 673, 0 }, { 0, 0, 674, 0 }, { 0, 0, 674, 0 },
   { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 },
   { 0, 0, 460, 0 }, { 0, 0, 460, 0 }, { 0, 0, 263, 0 }, { 0, 0, 263, 0 }
  }, { /* input: color-mapped-sRGB-rgb+alpha */
-  { 0, 6, 8, 0 }, { 0, 7, 8, 0 }, { 0, 75, 9, 0 }, { 0, 9, 9, 0 },
-  { 0, 585, 427, 0 }, { 0, 585, 427, 0 }, { 0, 717, 514, 0 }, { 0, 717, 514, 0 },
+  { 0, 6, 8, 0 }, { 0, 7, 8, 0 }, { 0, 75, 8, 0 }, { 0, 9, 8, 0 },
+  { 0, 585, 427, 0 }, { 0, 585, 427, 0 }, { 0, 717, 584, 0 }, { 0, 717, 584, 0 },
   { 0, 1, 1, 0 }, { 0, 1, 1, 0 }, { 0, 1, 0, 0 }, { 0, 0, 0, 0 },
   { 0, 13323, 460, 0 }, { 0, 427, 460, 0 }, { 0, 16480, 263, 0 }, { 0, 243, 263, 0 }
  }, { /* input: color-mapped-linear-gray */
@@ -107,7 +107,7 @@ static png_uint_16 gpc_error_via_linear[16][4/*out*/][4] =
  }, { /* input: sRGB-rgb */
   { 0, 0, 20, 0 }, { 0, 0, 20, 0 }, { 0, 0, 15, 0 }, { 0, 0, 15, 0 }
  }, { /* input: sRGB-rgb+alpha */
-  { 0, 16, 17, 0 }, { 0, 187, 17, 0 }, { 0, 15, 15, 0 }, { 0, 186, 15, 0 }
+  { 0, 12, 14, 0 }, { 0, 180, 14, 0 }, { 0, 15, 15, 0 }, { 0, 186, 15, 0 }
  }, { /* input: linear-gray */
   { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }, { 0, 0, 1, 0 }
  }, { /* input: linear-gray+alpha */
@@ -123,7 +123,7 @@ static png_uint_16 gpc_error_via_linear[16][4/*out*/][4] =
  }, { /* input: color-mapped-sRGB-rgb */
   { 0, 0, 13, 0 }, { 0, 0, 13, 0 }, { 0, 0, 14, 0 }, { 0, 0, 14, 0 }
  }, { /* input: color-mapped-sRGB-rgb+alpha */
-  { 0, 4, 8, 0 }, { 0, 9, 8, 0 }, { 0, 9, 5, 0 }, { 0, 32, 5, 0 }
+  { 0, 4, 8, 0 }, { 0, 9, 8, 0 }, { 0, 9, 9, 0 }, { 0, 32, 9, 0 }
  }, { /* input: color-mapped-linear-gray */
   { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }, { 0, 0, 0, 0 }
  }, { /* input: color-mapped-linear-gray+alpha */
@@ -138,27 +138,27 @@ static png_uint_16 gpc_error_to_colormap[8/*i*/][8/*o*/][4] =
 {
  { /* input: sRGB-gray */
   { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 }, { 0, 0, 9, 0 },
-  { 0, 0, 560, 0 }, { 0, 0, 560, 0 }, { 0, 0, 560, 0 }, { 0, 0, 560, 0 }
+  { 0, 0, 742, 0 }, { 0, 0, 742, 0 }, { 0, 0, 742, 0 }, { 0, 0, 742, 0 }
  }, { /* input: sRGB-gray+alpha */
-  { 0, 19, 9, 0 }, { 0, 255, 9, 25 }, { 0, 88, 9, 0 }, { 0, 255, 9, 25 },
-  { 0, 1012, 928, 0 }, { 0, 16026, 928, 6425 }, { 0, 1012, 928, 0 }, { 0, 16026, 928, 6425 }
+  { 0, 19, 6, 0 }, { 0, 255, 6, 25 }, { 0, 88, 6, 0 }, { 0, 255, 6, 25 },
+  { 0, 1012, 911, 0 }, { 0, 16026, 911, 6425 }, { 0, 1012, 911, 0 }, { 0, 16026, 911, 6425 }
  }, { /* input: sRGB-rgb */
   { 0, 0, 19, 0 }, { 0, 0, 19, 0 }, { 0, 0, 25, 0 }, { 0, 0, 25, 0 },
   { 0, 0, 962, 0 }, { 0, 0, 962, 0 }, { 0, 0, 13677, 0 }, { 0, 0, 13677, 0 }
  }, { /* input: sRGB-rgb+alpha */
   { 0, 63, 77, 0 }, { 0, 255, 19, 25 }, { 0, 225, 25, 0 }, { 0, 255, 25, 67 },
-  { 0, 17534, 18491, 0 }, { 0, 15736, 2824, 6425 }, { 0, 14019, 13677, 0 }, { 0, 50115, 13677, 17219 }
+  { 0, 17534, 18491, 0 }, { 0, 15998, 2824, 6425 }, { 0, 14103, 13677, 0 }, { 0, 50115, 13677, 17219 }
  }, { /* input: linear-gray */
   { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 73, 0 },
   { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }, { 0, 0, 18817, 0 }
  }, { /* input: linear-gray+alpha */
-  { 0, 74, 74, 0 }, { 0, 255, 74, 25 }, { 0, 99, 74, 0 }, { 0, 255, 74, 25 },
+  { 0, 74, 74, 0 }, { 0, 255, 74, 25 }, { 0, 100, 74, 0 }, { 0, 255, 74, 25 },
   { 0, 18919, 18907, 0 }, { 0, 24549, 18907, 6553 }, { 0, 18919, 18907, 0 }, { 0, 24549, 18907, 6553 }
  }, { /* input: linear-rgb */
   { 0, 0, 73, 0 }, { 0, 0, 73, 0 }, { 0, 0, 98, 0 }, { 0, 0, 98, 0 },
   { 0, 0, 18664, 0 }, { 0, 0, 18664, 0 }, { 0, 0, 24998, 0 }, { 0, 0, 24998, 0 }
  }, { /* input: linear-rgb+alpha */
-  { 0, 181, 196, 0 }, { 0, 255, 61, 25 }, { 206, 187, 98, 0 }, { 0, 255, 98, 67 },
+  { 0, 181, 196, 0 }, { 0, 255, 61, 25 }, { 206, 192, 98, 0 }, { 0, 255, 98, 67 },
   { 0, 18141, 18137, 0 }, { 0, 17494, 17504, 6553 }, { 0, 24979, 24992, 0 }, { 0, 49172, 24992, 17347 }
  }
 };

contrib/libtests/pngunknown.c

@@ -1,8 +1,8 @@
 
 /* pngunknown.c - test the read side unknown chunk handling
  *
- * Last changed in libpng 1.6.32 [August 24, 2017]
- * Copyright (c) 2015,2017 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.26 [October 20, 2016]
+ * Copyright (c) 2015,2016 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
  * This code is released under the libpng license.
@@ -114,7 +114,6 @@ typedef png_byte *png_const_bytep;
 #define png_PLTE PNG_U32( 80,  76,  84,  69)
 #define png_bKGD PNG_U32( 98,  75,  71,  68)
 #define png_cHRM PNG_U32( 99,  72,  82,  77)
-#define png_eXIf PNG_U32(101,  88,  73, 102) /* registered July 2017 */
 #define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
 #define png_gAMA PNG_U32(103,  65,  77,  65)
 #define png_gIFg PNG_U32(103,  73,  70, 103)
@@ -211,13 +210,6 @@ static struct
          1,
 #     endif
       1,  START, 0 },
-   { "eXIf", PNG_INFO_eXIf, png_eXIf,
-#     ifdef PNG_READ_eXIf_SUPPORTED
-         0,
-#     else
-         1,
-#     endif
-      1,  END, 0 },
    { "gAMA", PNG_INFO_gAMA, png_gAMA,
 #     ifdef PNG_READ_gAMA_SUPPORTED
          0,
@@ -622,7 +614,7 @@ get_unknown(display *d, png_infop info_ptr, int after_IDAT)
                   ++(d->error_count);
                   break;
                }
-               /* FALLTHROUGH */ /* (safe) */
+               /* FALL THROUGH (safe) */
             case PNG_HANDLE_CHUNK_ALWAYS:
                break;
          }
@@ -1098,7 +1090,7 @@ static const char *standard_tests[] =
  "sTER", "sTER=if-safe", 0,
  "IDAT", "default=discard", "IDAT=save", 0,
  "sAPI", "bKGD=save", "cHRM=save", "gAMA=save", "all=discard", "iCCP=save",
-   "sBIT=save", "sRGB=save", "eXIf=save", 0,
+   "sBIT=save", "sRGB=save", 0,
  0/*end*/
 };
 

contrib/libtests/pngvalid.c

@@ -1,8 +1,8 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.31 [July 27, 2017]
- * Copyright (c) 2014-2017 John Cunningham Bowler
+ * Last changed in libpng 1.6.27 [December 29, 2016]
+ * Copyright (c) 2014-2016 John Cunningham Bowler
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -6584,16 +6584,16 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
    {
    case PNG_COLOR_TYPE_PALETTE:
       if (dp->output_bit_depth > 8) goto error;
-      /* FALLTHROUGH */
+      /*FALL THROUGH*/
    case PNG_COLOR_TYPE_GRAY:
       if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 ||
          dp->output_bit_depth == 4)
          break;
-      /* FALLTHROUGH */
+      /*FALL THROUGH*/
    default:
       if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16)
          break;
-      /* FALLTHROUGH */
+      /*FALL THROUGH*/
    error:
       {
          char message[128];
@@ -7742,11 +7742,13 @@ image_transform_png_set_rgb_to_gray_ini(const image_transform *this,
           * NOTE: this number only affects the internal limit check in pngvalid,
           * it has no effect on the limits applied to the libpng values.
           */
-#if DIGITIZE
-          that->pm->limit += pow( 2.0/255, data.gamma);
-#else
-          that->pm->limit += pow( 1.0/255, data.gamma);
-#endif
+         that->pm->limit += pow(
+#        if DIGITIZE
+            2.0
+#        else
+            1.0
+#        endif
+            /255, data.gamma);
       }
    }
 
@@ -9994,9 +9996,9 @@ gamma_component_validate(const char *name, const validate_info *vi,
                case PNG_BACKGROUND_GAMMA_FILE:
                case PNG_BACKGROUND_GAMMA_UNIQUE:
                   use_background = (alpha >= 0 && alpha < 1);
+                  /*FALL THROUGH*/
 #           endif
 #           ifdef PNG_READ_ALPHA_MODE_SUPPORTED
-               /* FALLTHROUGH */
                case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD:
                case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN:
                case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED:

contrib/mips-msa/README

@@ -1,83 +0,0 @@
-OPERATING SYSTEM SPECIFIC MIPS MSA DETECTION
---------------------------------------------
-
-Detection of the ability to execute MIPS MSA on an MIPS processor requires
-operating system support.  (The information is not available in user mode.)
-
-HOW TO USE THIS
----------------
-
-This directory contains C code fragments that can be included in mips/mips_init.c
-by setting the macro PNG_MIPS_MSA_FILE to the file name in "" or <> at build
-time.  This setting is not recorded in pnglibconf.h and can be changed simply by
-rebuilding mips/msa_init.o with the required macro definition.
-
-For any of this code to be used the MIPS MSA code must be enabled and run time
-checks must be supported.  I.e.:
-
-#if PNG_MIPS_MSA_OPT > 0
-#ifdef PNG_MIPS_MSA_CHECK_SUPPORTED
-
-This is done in a 'configure' build by passing configure the argument:
-
-   --enable-mips-msa=check
-
-Apart from the basic Linux implementation in contrib/mips-msa/linux.c this code
-is unsupported.  That means that it is not even compiled on a regular basis and
-may be broken in any given minor release.
-
-FILE FORMAT
------------
-
-Each file documents its testing status as of the last time it was tested (which
-may have been a long time ago):
-
-STATUS: one of:
-   SUPPORTED: This indicates that the file is included in the regularly
-         performed test builds and bugs are fixed when discovered.
-   COMPILED: This indicates that the code did compile at least once.  See the
-         more detailed description for the extent to which the result was
-         successful.
-   TESTED: This means the code was fully compiled into the libpng test programs
-         and these were run at least once.
-
-BUG REPORTS: an email address to which to send reports of problems
-
-The file is a fragment of C code. It should not define any 'extern' symbols;
-everything should be static.  It must define the function:
-
-static int png_have_msa(png_structp png_ptr);
-
-That function must return 1 if MIPS MSA instructions are supported, 0 if not.
-It must not execute png_error unless it detects a bug.  A png_error will prevent
-the reading of the PNG and in the future, writing too.
-
-BUG REPORTS
------------
-
-If you mail a bug report for any file that is not SUPPORTED there may only be
-limited response.  Consider fixing it and sending a patch to fix the problem -
-this is more likely to result in action.
-
-CONTRIBUTIONS
--------------
-
-You may send contributions of new implementations to
-png-mng-implement@sourceforge.net.  Please write code in strict C90 C where
-possible.  Obviously OS dependencies are to be expected.  If you submit code you
-must have the authors permission and it must have a license that is acceptable
-to the current maintainer; in particular that license must permit modification
-and redistribution.
-
-Please try to make the contribution a single file and give the file a clear and
-unambiguous name that identifies the target OS.  If multiple files really are
-required put them all in a sub-directory.
-
-You must also be prepared to handle bug reports from users of the code, either
-by joining the png-mng-implement mailing list or by providing an email for the
-"BUG REPORTS" entry or both.  Please make sure that the header of the file
-contains the STATUS and BUG REPORTS fields as above.
-
-Please list the OS requirements as precisely as possible.  Ideally you should
-also list the environment in which the code has been tested and certainly list
-any environments where you suspect it might not work.

contrib/mips-msa/linux.c

@@ -1,64 +0,0 @@
-/* contrib/mips-msa/linux.c
- *
- * Copyright (c) 2016 Glenn Randers-Pehrson
- * Written by Mandar Sahastrabuddhe, 2016.
- * Last changed in libpng 1.6.25beta03 [August 29, 2016]
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * SEE contrib/mips-msa/README before reporting bugs
- *
- * STATUS: SUPPORTED
- * BUG REPORTS: png-mng-implement@sourceforge.net
- *
- * png_have_msa implemented for Linux by reading the widely available
- * pseudo-file /proc/cpuinfo.
- *
- * This code is strict ANSI-C and is probably moderately portable; it does
- * however use <stdio.h> and it assumes that /proc/cpuinfo is never localized.
- */
-
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-
-static int
-png_have_msa(png_structp png_ptr)
-{
-   FILE *f = fopen("/proc/cpuinfo", "rb");
-
-   char *string = "msa";
-   char word[10];
-
-   if (f != NULL)
-   {
-      while(!feof(f))
-      {
-         int ch = fgetc(f);
-         static int i = 0;
-
-         while(!(ch <= 32))
-         {
-            word[i++] = ch;
-            ch = fgetc(f);
-         }
-
-         int val = strcmp(string, word);
-
-         if (val == 0)
-            return 1;
-
-         i = 0;
-         memset(word, 0, 10);
-      }
-
-      fclose(f);
-   }
-#ifdef PNG_WARNINGS_SUPPORTED
-   else
-      png_warning(png_ptr, "/proc/cpuinfo open failed");
-#endif
-   return 0;
-}

contrib/neon/arm_init.c

@@ -1,9 +1,9 @@
 
 /* arm_init.c - NEON optimised filter functions
  *
- * Copyright (c) 2014,2016 Glenn Randers-Pehrson
+ * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -14,7 +14,8 @@
  */
 #define _POSIX_SOURCE 1
 
-#include "../pngpriv.h"
+#include "../../pngpriv.h"
+#define PNG_SRC_FILE PNG_SRC_FILE_arm_arm_init
 
 #ifdef PNG_READ_SUPPORTED
 
@@ -66,7 +67,6 @@ png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
     * wrong order of the 'ON' and 'default' cases.  UNSET now defaults to OFF,
     * as documented in png.h
     */
-   png_debug(1, "in png_init_filter_functions_neon");
 #ifdef PNG_ARM_NEON_API_SUPPORTED
    switch ((pp->options >> PNG_ARM_NEON) & 3)
    {

contrib/neon/extensions.ac

@@ -0,0 +1,10 @@
+# To just this extension either copy the 'sinclude' line and the setting of
+# libpng_automake_extensions into contrib/extensions.am or link/copy the whole
+# file there.  Do the same with the associated file extensions.am
+#
+# Include the ARM NEON extension:
+sinclude([contrib/neon/neon.ac])
+#
+# If any of the extensions require automake support (this is likely) automake
+# must include the file contrib/extensions.am
+libpng_automake_extensions="yes"

contrib/neon/extensions.am

@@ -0,0 +1,5 @@
+# To just this extension either copy the 'include' line into
+# contrib/extensions.am or link/copy the whole file there.  Do the same with the
+# associated file extensions.ac
+# Include the ARM NEON extension:
+include %reldir%/neon/neon.am

contrib/neon/filter_neon.S

@@ -1,9 +1,9 @@
 
 /* filter_neon.S - NEON optimised filter functions
  *
- * Copyright (c) 2014,2017 Glenn Randers-Pehrson
+ * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.31 [July 27, 2017]
+ * Last changed in libpng 1.6.16 [(PENDING RELEASE)]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -14,9 +14,9 @@
  * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION.
  */
 #define PNG_VERSION_INFO_ONLY
-#include "../pngpriv.h"
+#include "../../pngpriv.h"
 
-#if (defined(__linux__) || defined(__FreeBSD__)) && defined(__ELF__)
+#if defined(__linux__) && defined(__ELF__)
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
 

contrib/neon/filter_neon_intrinsics.c

@@ -1,18 +1,19 @@
 
 /* filter_neon_intrinsics.c - NEON optimised filter functions
  *
- * Copyright (c) 2014,2016 Glenn Randers-Pehrson
+ * Copyright (c) 2014 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 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.16 [December 22, 2014]
  *
  * 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"
+#include "../../pngpriv.h"
+#define PNG_SRC_FILE PNG_SRC_FILE_arm_filter_neon_intrinsics
 
 #ifdef PNG_READ_SUPPORTED
 
@@ -40,15 +41,13 @@
 #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_read_filter_row_up_neon(png_alloc_size_t rowbytes, unsigned int bpp,
+   png_bytep row, png_const_bytep prev_row)
 {
    png_bytep rp = row;
-   png_bytep rp_stop = row + row_info->rowbytes;
+   png_bytep rp_stop = row + rowbytes;
    png_const_bytep pp = prev_row;
 
-   png_debug(1, "in png_read_filter_row_up_neon");
-
    for (; rp < rp_stop; rp += 16, pp += 16)
    {
       uint8x16_t qrp, qpp;
@@ -58,14 +57,15 @@ png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row,
       qrp = vaddq_u8(qrp, qpp);
       vst1q_u8(rp, qrp);
    }
+
+   PNG_UNUSED(bpp)
 }
 
 void
-png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev_row)
+png_read_filter_row_sub3_neon(png_alloc_size_t rowbytes, unsigned int bpp, png_bytep row, png_const_bytep prev_row)
 {
    png_bytep rp = row;
-   png_bytep rp_stop = row + row_info->rowbytes;
+   png_bytep rp_stop = row + rowbytes;
 
    uint8x16_t vtmp = vld1q_u8(rp);
    uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp);
@@ -74,8 +74,6 @@ png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
    uint8x8x4_t vdest;
    vdest.val[3] = vdup_n_u8(0);
 
-   png_debug(1, "in png_read_filter_row_sub3_neon");
-
    for (; rp < rp_stop;)
    {
       uint8x8_t vtmp1, vtmp2;
@@ -104,21 +102,20 @@ png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
       rp += 3;
    }
 
+   PNG_UNUSED(bpp)
    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_read_filter_row_sub4_neon(png_alloc_size_t rowbytes, unsigned int bpp,
+   png_bytep row, png_const_bytep prev_row)
 {
    png_bytep rp = row;
-   png_bytep rp_stop = row + row_info->rowbytes;
+   png_bytep rp_stop = row + rowbytes;
 
    uint8x8x4_t vdest;
    vdest.val[3] = vdup_n_u8(0);
 
-   png_debug(1, "in png_read_filter_row_sub4_neon");
-
    for (; rp < rp_stop; rp += 16)
    {
       uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp));
@@ -133,16 +130,17 @@ png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
       vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
    }
 
+   PNG_UNUSED(bpp)
    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_read_filter_row_avg3_neon(png_alloc_size_t rowbytes, unsigned int bpp,
+   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;
+   png_bytep rp_stop = row + rowbytes;
 
    uint8x16_t vtmp;
    uint8x8x2_t *vrpt;
@@ -154,8 +152,6 @@ png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
    vrpt = png_ptr(uint8x8x2_t,&vtmp);
    vrp = *vrpt;
 
-   png_debug(1, "in png_read_filter_row_avg3_neon");
-
    for (; rp < rp_stop; pp += 12)
    {
       uint8x8_t vtmp1, vtmp2, vtmp3;
@@ -202,21 +198,21 @@ png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
       vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
       rp += 3;
    }
+
+   PNG_UNUSED(bpp)
 }
 
 void
-png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev_row)
+png_read_filter_row_avg4_neon(png_alloc_size_t rowbytes, unsigned int bpp,
+   png_bytep row, png_const_bytep prev_row)
 {
    png_bytep rp = row;
-   png_bytep rp_stop = row + row_info->rowbytes;
+   png_bytep rp_stop = row + rowbytes;
    png_const_bytep pp = prev_row;
 
    uint8x8x4_t vdest;
    vdest.val[3] = vdup_n_u8(0);
 
-   png_debug(1, "in png_read_filter_row_avg4_neon");
-
    for (; rp < rp_stop; rp += 16, pp += 16)
    {
       uint32x2x4_t vtmp;
@@ -242,6 +238,8 @@ png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
 
       vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
    }
+
+   PNG_UNUSED(bpp)
 }
 
 static uint8x8_t
@@ -272,12 +270,12 @@ paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c)
 }
 
 void
-png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev_row)
+png_read_filter_row_paeth3_neon(png_alloc_size_t rowbytes, unsigned int bpp,
+   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;
+   png_bytep rp_stop = row + rowbytes;
 
    uint8x16_t vtmp;
    uint8x8x2_t *vrpt;
@@ -290,8 +288,6 @@ png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
    vrpt = png_ptr(uint8x8x2_t,&vtmp);
    vrp = *vrpt;
 
-   png_debug(1, "in png_read_filter_row_paeth3_neon");
-
    for (; rp < rp_stop; pp += 12)
    {
       uint8x8x2_t *vppt;
@@ -337,22 +333,22 @@ png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
       vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
       rp += 3;
    }
+
+   PNG_UNUSED(bpp)
 }
 
 void
-png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev_row)
+png_read_filter_row_paeth4_neon(png_alloc_size_t rowbytes, unsigned int bpp,
+   png_bytep row, png_const_bytep prev_row)
 {
    png_bytep rp = row;
-   png_bytep rp_stop = row + row_info->rowbytes;
+   png_bytep rp_stop = row + rowbytes;
    png_const_bytep pp = prev_row;
 
    uint8x8_t vlast = vdup_n_u8(0);
    uint8x8x4_t vdest;
    vdest.val[3] = vdup_n_u8(0);
 
-   png_debug(1, "in png_read_filter_row_paeth4_neon");
-
    for (; rp < rp_stop; rp += 16, pp += 16)
    {
       uint32x2x4_t vtmp;
@@ -380,8 +376,9 @@ png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
 
       vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
    }
-}
 
+   PNG_UNUSED(bpp)
+}
 #endif /* PNG_ARM_NEON_OPT > 0 */
 #endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */
 #endif /* READ */

contrib/neon/neon.ac

@@ -0,0 +1,47 @@
+# LIBPNG EXTENSION: NEON
+#
+# ARM NEON (SIMD) support.
+#
+# This file contains configure.ac additions to libpng configure to enable
+# building of the ARM NEON filter optimizations.
+#
+AC_ARG_ENABLE([arm-neon],
+   AS_HELP_STRING([[[--enable-arm-neon]]],
+      [Enable ARM NEON optimizations: =no/off, check, api, yes/on:]
+      [no/off: disable the optimizations; check: use internal checking code]
+      [(deprecated and poorly supported); api: disable by default, enable by]
+      [a call to png_set_option; yes/on: turn on unconditionally.]
+      [If not specified: determined by the compiler.]),
+   [case "$enableval" in
+      no|off)
+         # disable the default enabling on __ARM_NEON__ systems:
+         AC_DEFINE([PNG_ARM_NEON_OPT], [0],
+                   [Disable ARM Neon optimizations])
+         # Prevent inclusion of the assembler files below:
+         enable_arm_neon=no;;
+      check)
+         AC_DEFINE([PNG_ARM_NEON_CHECK_SUPPORTED], [],
+                   [Check for ARM Neon support at run-time]);;
+      api)
+         AC_DEFINE([PNG_ARM_NEON_API_SUPPORTED], [],
+                   [Turn on ARM Neon optimizations at run-time]);;
+      yes|on)
+         AC_DEFINE([PNG_ARM_NEON_OPT], [2],
+                   [Enable ARM Neon optimizations])
+         AC_MSG_WARN([--enable-arm-neon: please specify 'check' or 'api', if]
+            [you want the optimizations unconditionally pass -mfpu=neon]
+            [to the compiler.]);;
+      *)
+         AC_MSG_ERROR([--enable-arm-neon=${enable_arm_neon}: invalid value])
+   esac])
+
+# Add ARM specific files to all builds where the host_cpu is arm ('arm*') or
+# where ARM optimizations were explicitly requested (this allows a fallback if a
+# future host CPU does not match 'arm*')
+
+AM_CONDITIONAL([PNG_ARM_NEON],
+   [test "$enable_arm_neon" != 'no' &&
+    case "$host_cpu" in
+      arm*|aarch64*) :;;
+      *)    test "$enable_arm_neon" != '';;
+    esac])

contrib/neon/neon.am

@@ -0,0 +1,27 @@
+# contrib/neon/neon.am
+#
+# This is an automake fragment included by the top-level Makefile.am if
+# contrib/neon/neon.ac is included in configure
+#
+# It builds the source files in this directory into ARM hardware support for
+# libpng.
+#
+if PNG_ARM_NEON
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += %D%/arm_init.c\
+	%D%/filter_neon.S %D%/filter_neon_intrinsics.c
+
+DFA_EXTENSION += ${srcdir}/%D%/neon.dfa
+
+# This causes pngpriv.h to include the named header.  It is VERY important to
+# understand that this MUST be defined and the header MUST define internal
+# 'extern' functions with PNG_INTERNAL_FUNCTION.  This allows vendors to use
+# static library builds of libpng without clashing with the installed system
+# libpng; see the libpng-prefix option in configure.ac  The value of this
+# #define is included in pnglibconf.h
+#
+# NOTE: you must include the double quotes in the value and you must therefore
+# support the whole thing with single quotes.  If you need to use <> for a
+# header be aware that if you miss out the single quotes you will create a
+# random file.
+AM_CPPFLAGS += -DPNG_EXTENSION_HEADER='"%D%/neon.h"'
+endif

contrib/neon/neon.dfa

@@ -0,0 +1,41 @@
+# contrib/arm/neon.dfa
+#
+# This is a dfa fragment that is added to DFA_HARDWARE in Makefile.am and
+# consequently is inserted after scripts/pnglibconf.dfa to define extra,
+# hardware, options.
+#
+# The following are required in any fragment to record the copyright holder of
+# the *changes* and the appropriate email for bug reports.  Note that the
+# copyright here is just for the specific configuration; additional files may
+# have additional and/or different copyrights.
+#
+# Later settings (e.g. in user.dfa) will override these settings.
+#
+setting USER_PRIVATEBUILD default "John Bowler"
+setting USER_BUG_REPORTS default "jbowler@acm.org"
+#
+# These options are specific to the ARM NEON hardware optimizations.  At present
+# these optimizations depend on GCC specific pre-processing of an assembler (.S)
+# file so they probably won't work with other compilers.
+#
+# ARM_NEON_OPT: unset: check at compile time (__ARM_NEON__ must be defined by
+#                      the compiler, typically as a result of specifying
+#                      CC="gcc -mfpu=neon".)
+#                   0: disable (even if the CPU has a NEON FPU.)
+#                   1: check at run time (via ARM_NEON_{API,CHECK})
+#                   2: switch on unconditionally (inadvisable - instead pass
+#                      -mfpu=neon to GCC in CC)
+#           When building libpng avoid using any setting other than '0'; '1' is
+#           set automatically when either 'API' or 'CHECK' are configured in,
+#           '2' should not be necessary as -mfpu=neon will achieve the same
+#           effect as well as applying NEON optimizations to the rest of the
+#           libpng code.
+#           NOTE: any setting other than '0' requires ALIGNED_MEMORY
+# ARM_NEON_API:   (PNG_ARM_NEON == 1) allow the optimization to be switched on
+#                 with png_set_option
+# ARM_NEON_CHECK: (PNG_ARM_NEON == 1) compile a run-time check to see if Neon
+#                 extensions are supported. This is poorly supported and
+#                 deprecated - use the png_set_option API.
+setting ARM_NEON_OPT
+option ARM_NEON_API disabled enables SET_OPTION sets ARM_NEON_OPT 1
+option ARM_NEON_CHECK disabled sets ARM_NEON_OPT 1

contrib/neon/neon.h

@@ -0,0 +1,124 @@
+/* Compile time options.
+ * =====================
+ * In a multi-arch build the compiler may compile the code several times for the
+ * same object module, producing different binaries for different architectures.
+ * When this happens configure-time setting of the target host options cannot be
+ * done.  An example is iOS vs Android compilation of ARM NEON support.
+ *
+ * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because
+ * this is not possible with certain compilers (Oracle SUN OS CC), as a result
+ * it is necessary to ensure that all extern functions that *might* be used
+ * regardless of $(CFLAGS) get declared in this file.  The test on __ARM_NEON
+ * below is one example of this behavior because it is controlled by the
+ * presence or not of -mfpu=neon on the GCC command line, it is possible to do
+ * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely
+ * do this.
+ */
+#ifndef PNG_ARM_NEON_OPT
+   /* ARM NEON optimizations are being controlled by the compiler settings,
+    * typically the target FPU.  If the FPU supports NEON instructions then the
+    * compiler will define __ARM_NEON and we can rely unconditionally on NEON
+    * instructions not crashing, otherwise we must disable use of NEON
+    * instructions.
+    *
+    * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they
+    * can only be turned on automatically if that is supported too.  If
+    * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail
+    * to compile with an appropriate #error if ALIGNED_MEMORY has been turned
+    * off.
+    *
+    * Note that older versions of GCC defined __ARM_NEON__; this is no longer
+    * supported.  Also 32-bit ARM versions of GCC required the NEON FPU mode to
+    * be turned on explicitly on the command line.  If this is not done (on
+    * 32-bit ARM) NEON code will not be included.
+    *
+    * To disable ARM_NEON optimizations entirely, and skip compiling the
+    * associated assembler code, pass --enable-arm-neon=no to configure
+    * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS.
+    */
+#  if defined(__ARM_NEON) && defined(PNG_ALIGNED_MEMORY_SUPPORTED)
+#     define PNG_ARM_NEON_OPT 2
+#  else
+#     define PNG_ARM_NEON_OPT 0
+#  endif
+#endif
+
+#if PNG_ARM_NEON_OPT > 0
+   /* NEON optimizations are to be at least considered by libpng, so enable the
+    * callbacks to do this.
+    */
+#  define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon
+
+   /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used
+    * if possible - if __ARM_NEON is set and the compiler version is not known
+    * to be broken.  This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can
+    * be:
+    *
+    *    1  The intrinsics code (the default with __ARM_NEON)
+    *    2  The hand coded assembler (the default without __ARM_NEON)
+    *
+    * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however
+    * this is *NOT* supported and may cease to work even after a minor revision
+    * to libpng.  It *is* valid to do this for testing purposes, e.g. speed
+    * testing or a new compiler, but the results should be communicated to the
+    * libpng implementation list for incorporation in the next minor release.
+    */
+#  ifndef PNG_ARM_NEON_IMPLEMENTATION
+#     ifdef __ARM_NEON
+#        if defined(__clang__)
+            /* At present it is unknown by the libpng developers which versions
+             * of clang support the intrinsics, however some or perhaps all
+             * versions do not work with the assembler so this may be
+             * irrelevant, so just use the default (do nothing here.)
+             */
+#        elif defined(__GNUC__)
+            /* GCC 4.5.4 NEON support is known to be broken.  4.6.3 is known to
+             * work, so if this *is* GCC, or G++, look for a version >4.5
+             */
+#           if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)
+#              define PNG_ARM_NEON_IMPLEMENTATION 2
+#           endif /* no GNUC support */
+#        endif /* __GNUC__ */
+#     else /* !defined __ARM_NEON */
+         /* The 'intrinsics' code simply won't compile without compiler support
+          * and that support switches on __ARM_NEON, so use the assembler:
+          */
+#        define PNG_ARM_NEON_IMPLEMENTATION 2
+#     endif /* __ARM_NEON */
+#  endif /* !defined PNG_ARM_NEON_IMPLEMENTATION */
+
+#  ifndef PNG_ARM_NEON_IMPLEMENTATION
+      /* Use the intrinsics code by default. */
+#     define PNG_ARM_NEON_IMPLEMENTATION 1
+#  endif
+#endif /* PNG_ARM_NEON_OPT > 0 */
+
+#ifdef PNG_SET_OPTION_SUPPORTED
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+#  define PNG_ARM_NEON   0 /* HARDWARE: ARM Neon SIMD instructions supported */
+#endif
+#endif /* SET_OPTION */
+
+#if PNG_ARM_NEON_OPT > 0
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon,
+   (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row,
+    png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon,
+   (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row,
+    png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon,
+   (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row,
+    png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon,
+   (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row,
+    png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,
+   (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row,
+    png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,
+   (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row,
+    png_const_bytep prev_row),PNG_EMPTY);
+PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,
+   (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row,
+    png_const_bytep prev_row),PNG_EMPTY);
+#endif

contrib/oss-fuzz/README.txt

@@ -1,32 +0,0 @@
-Last changed in libpng 1.6.32 [August 24, 2017]
-Copyright (c) 2017 Glenn Randers-Pehrson
-
-This code is released under the libpng license.
-For conditions of distribution and use, see the disclaimer
-and license in png.h
-
-Files in this directory are used by the oss-fuzz project
-(https://github.com/google/oss-fuzz/tree/master/projects/libpng).
-for "fuzzing" libpng.
-
-They were licensed by Google Inc, using the BSD-like Chromium license,
-which may be found at https://cs.chromium.org/chromium/src/LICENSE, or, if
-noted in the source, under the Apache-2.0 license, which may
-be found at http://www.apache.org/licenses/LICENSE-2.0 .
-If they have been modified, the derivatives are copyright Glenn Randers-Pehson
-and are released under the same licenses as the originals.  Several of
-the original files (libpng_read_fuzzer.options, png.dict, project.yaml)
-had no licensing information; we assumed that these were under the Chromium
-license. Any new files are released under the libpng license (see png.h).
-
-The files are
-                            Original
- Filename                   or derived   Copyright          License
- =========================  ==========   ================   ==========
- build.sh                   derived      2017, Glenn R-P    Apache 2.0
- libpng_read_fuzzer.cc      derived      2017, Glenn R-P    Chromium
- libpng_read_fuzzer.options original     2015, Chrome Devs  Chromium
- png.dict                   original     2015, Chrome Devs  Chromium
- README.txt (this file)     original     2017, GLenn R-P    libpng
-
-To do: exercise the progressive reader.

contrib/oss-fuzz/build.sh

@@ -1,47 +0,0 @@
-#!/bin/bash -eu
-# Copyright 2017 Glenn Randers-Pehrson
-# Copyright 2016 Google Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-# Last changed in libpng 1.6.32 [August 24, 2017]
-#
-# Revisions by Glenn Randers-Pehson, 2017:
-# 1. Build only the library, not the tools (changed "make -j$(nproc) all" to
-#     "make -j$(nproc) libpng16.la").
-# 2. Disabled WARNING and WRITE options in pnglibconf.dfa.
-################################################################################
-
-# Disable logging via library build configuration control.
-cat scripts/pnglibconf.dfa | \
-  sed -e "s/option STDIO/option STDIO disabled/" \
-      -e "s/option WARNING /option WARNING disabled/" \
-      -e "s/option WRITE enables WRITE_INT_FUNCTIONS/option WRITE disabled/" \
-> scripts/pnglibconf.dfa.temp
-mv scripts/pnglibconf.dfa.temp scripts/pnglibconf.dfa
-
-# build the library.
-autoreconf -f -i
-./configure
-make -j$(nproc) clean
-make -j$(nproc) libpng16.la
-
-# build libpng_read_fuzzer.
-$CXX $CXXFLAGS -std=c++11 -I. \
-     $SRC/libpng_read_fuzzer.cc -o $OUT/libpng_read_fuzzer \
-     -lFuzzingEngine .libs/libpng16.a -lz
-
-# add seed corpus.
-find $SRC/libpng/contrib/pngsuite -name "*.png" | xargs zip $OUT/libpng_read_fuzzer_seed_corpus.zip
-
-cp $SRC/*.dict $SRC/*.options $OUT/

contrib/oss-fuzz/libpng_read_fuzzer.cc

@@ -1,154 +0,0 @@
-
-// libpng_read_fuzzer.cc
-// Copyright 2017 Glenn Randers-Pehrson
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that may
-// be found in the LICENSE file https://cs.chromium.org/chromium/src/LICENSE
-
-// Last changed in libpng 1.6.32 [August 24, 2017]
-
-// The modifications in 2017 by Glenn Randers-Pehrson include
-// 1. addition of a PNG_CLEANUP macro,
-// 2. setting the option to ignore ADLER32 checksums,
-// 3. adding "#include <string.h>" which is needed on some platforms
-//    to provide memcpy().
-
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-
-#include <vector>
-
-#define PNG_INTERNAL
-#include "png.h"
-
-#define PNG_CLEANUP \
-    if(png_handler.png_ptr) \
-    { \
-      if (png_handler.info_ptr) \
-        png_destroy_read_struct(&png_handler.png_ptr, &png_handler.info_ptr,\
-          nullptr); \
-      else \
-        png_destroy_read_struct(&png_handler.png_ptr, nullptr, nullptr); \
-     }
-
-struct BufState {
-  const uint8_t* data;
-  size_t bytes_left;
-};
-
-struct PngObjectHandler {
-  png_infop info_ptr = nullptr;
-  png_structp png_ptr = nullptr;
-  png_voidp row_ptr = nullptr;
-  BufState* buf_state = nullptr;
-
-  ~PngObjectHandler() {
-    if (row_ptr && png_ptr) {
-      png_free(png_ptr, row_ptr);
-    }
-    if (png_ptr && info_ptr) {
-      png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
-    }
-    delete buf_state;
-  }
-};
-
-void user_read_data(png_structp png_ptr, png_bytep data, png_size_t length) {
-  BufState* buf_state = static_cast<BufState*>(png_get_io_ptr(png_ptr));
-  if (length > buf_state->bytes_left) {
-    png_error(png_ptr, "read error");
-  }
-  memcpy(data, buf_state->data, length);
-  buf_state->bytes_left -= length;
-  buf_state->data += length;
-}
-
-static const int kPngHeaderSize = 8;
-
-// Entry point for LibFuzzer.
-// Roughly follows the libpng book example:
-// http://www.libpng.org/pub/png/book/chapter13.html
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  if (size < kPngHeaderSize) {
-    return 0;
-  }
-
-  std::vector<unsigned char> v(data, data + size);
-  if (png_sig_cmp(v.data(), 0, kPngHeaderSize)) {
-    // not a PNG.
-    return 0;
-  }
-
-  PngObjectHandler png_handler;
-  png_handler.png_ptr = png_create_read_struct
-    (PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
-  if (!png_handler.png_ptr) {
-    return 0;
-  }
-
-  png_handler.info_ptr = png_create_info_struct(png_handler.png_ptr);
-  if (!png_handler.info_ptr) {
-    PNG_CLEANUP
-    return 0;
-  }
-
-  png_set_crc_action(png_handler.png_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
-#ifdef PNG_IGNORE_ADLER32
-  png_set_option(png_handler.png_ptr, PNG_IGNORE_ADLER32, PNG_OPTION_ON);
-#endif
-
-  // Setting up reading from buffer.
-  png_handler.buf_state = new BufState();
-  png_handler.buf_state->data = data + kPngHeaderSize;
-  png_handler.buf_state->bytes_left = size - kPngHeaderSize;
-  png_set_read_fn(png_handler.png_ptr, png_handler.buf_state, user_read_data);
-  png_set_sig_bytes(png_handler.png_ptr, kPngHeaderSize);
-
-  if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
-    PNG_CLEANUP
-    return 0;
-  }
-
-  // Reading.
-  png_read_info(png_handler.png_ptr, png_handler.info_ptr);
-  png_handler.row_ptr = png_malloc(
-      png_handler.png_ptr, png_get_rowbytes(png_handler.png_ptr,
-                                               png_handler.info_ptr));
-
-  // reset error handler to put png_deleter into scope.
-  if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
-    PNG_CLEANUP
-    return 0;
-  }
-
-  png_uint_32 width, height;
-  int bit_depth, color_type, interlace_type, compression_type;
-  int filter_type;
-
-  if (!png_get_IHDR(png_handler.png_ptr, png_handler.info_ptr, &width,
-                    &height, &bit_depth, &color_type, &interlace_type,
-                    &compression_type, &filter_type)) {
-    PNG_CLEANUP
-    return 0;
-  }
-
-  // This is going to be too slow.
-  if (width && height > 100000000 / width) {
-    PNG_CLEANUP
-    return 0;
-  }
-
-  int passes = png_set_interlace_handling(png_handler.png_ptr);
-  png_start_read_image(png_handler.png_ptr);
-
-  for (int pass = 0; pass < passes; ++pass) {
-    for (png_uint_32 y = 0; y < height; ++y) {
-      png_read_row(png_handler.png_ptr,
-                   static_cast<png_bytep>(png_handler.row_ptr), nullptr);
-    }
-  }
-
-  PNG_CLEANUP
-  return 0;
-}

contrib/oss-fuzz/libpng_read_fuzzer.options

@@ -1,2 +0,0 @@
-[libfuzzer]
-dict = png.dict

contrib/oss-fuzz/png.dict

@@ -1,39 +0,0 @@
-#
-# AFL dictionary for PNG images
-# -----------------------------
-#
-# Just the basic, standard-originating sections; does not include vendor
-# extensions.
-#
-# Created by Michal Zalewski <lcamtuf@google.com>
-#
-
-header_png="\x89PNG\x0d\x0a\x1a\x0a"
-
-section_IDAT="IDAT"
-section_IEND="IEND"
-section_IHDR="IHDR"
-section_PLTE="PLTE"
-section_bKGD="bKGD"
-section_cHRM="cHRM"
-section_eXIf="eXIf"
-section_fRAc="fRAc"
-section_gAMA="gAMA"
-section_gIFg="gIFg"
-section_gIFt="gIFt"
-section_gIFx="gIFx"
-section_hIST="hIST"
-section_iCCP="iCCP"
-section_iTXt="iTXt"
-section_oFFs="oFFs"
-section_pCAL="pCAL"
-section_pHYs="pHYs"
-section_sBIT="sBIT"
-section_sCAL="sCAL"
-section_sPLT="sPLT"
-section_sRGB="sRGB"
-section_sTER="sTER"
-section_tEXt="tEXt"
-section_tIME="tIME"
-section_tRNS="tRNS"
-section_zTXt="zTXt"

contrib/pngminim/decoder/makefile

@@ -56,7 +56,7 @@ PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
 	pngset$(C) pngtrans$(C)
 	
 # Standard headers
-PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngchunk.h
 
 # Machine generated headers
 PNGCONF=pnglibconf.h

contrib/pngminim/decoder/pngusr.dfa

@@ -36,5 +36,7 @@ option FLOATING_ARITHMETIC off
 option SETJMP on
 option STDIO on
 option READ_EXPAND on
+option READ_IMAGE on
+option READ_INTERLACING on
 option READ_STRIP_16_TO_8 on
 option USER_LIMITS on

contrib/pngminim/decoder/pngusr.h

@@ -18,6 +18,7 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
+#define PNG_RELEASE_BUILD 1
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINRDPNGCONF_H */

contrib/pngminim/encoder/makefile

@@ -56,7 +56,7 @@ PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
 	pngwtran$(C) pngwutil$(C)
 
 # Standard headers
-PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngchunk.h
 
 # Machine generated headers
 PNGCONF=pnglibconf.h

contrib/pngminim/encoder/pngusr.h

@@ -18,6 +18,7 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
+#define PNG_RELEASE_BUILD 1
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINWRPNGCONF_H */

contrib/pngminim/preader/makefile

@@ -72,7 +72,7 @@ PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
 	pngset$(C) pngtrans$(C)
 
 # Standard headers
-PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngchunk.h
 
 # Machine generated headers
 PNGCONF=pnglibconf.h

contrib/pngminim/preader/pngusr.dfa

@@ -36,5 +36,6 @@ option STDIO on
 option READ_bKGD on
 option READ_GAMMA on
 option READ_EXPAND on
+option READ_INTERLACING on
 option READ_STRIP_16_TO_8 on
 option READ_GRAY_TO_RGB on

contrib/pngminim/preader/pngusr.h

@@ -18,6 +18,7 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
+#define PNG_RELEASE_BUILD 1
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINPRDPNGCONF_H */

contrib/pngminus/README

@@ -146,7 +146,7 @@ The Turbo bug
 The end
 -------
 Willem van Schaik
-mailto:willem at schaik.com
+mailto:willem@schaik.com
 http://www.schaik.com/png/
 -------
 Oct 1999

contrib/pngminus/makefile.std

@@ -8,9 +8,9 @@ LD=$(CC)
 RM=rm -f
 
 #PNGPATH = /usr/local
-#PNGINC = -I$(PNGPATH)/include/libpng16
-#PNGLIB = -L$(PNGPATH)/lib -lpng16
-#PNGLIBS = $(PNGPATH)/lib/libpng16.a
+#PNGINC = -I$(PNGPATH)/include/libpng17
+#PNGLIB = -L$(PNGPATH)/lib -lpng17
+#PNGLIBS = $(PNGPATH)/lib/libpng17.a
 PNGINC = -I../..
 PNGLIB = -L../.. -lpng
 PNGLIBS = ../../libpng.a
@@ -23,8 +23,7 @@ ZINC = -I../../../zlib
 ZLIB = -L../../../zlib -lz
 ZLIBS = ../../../zlib/libz.a
 
-CPPFLAGS=$(PNGINC) $(ZINC)
-CFLAGS=
+CFLAGS=$(PNGINC) $(ZINC)
 LDLIBS=$(PNGLIB) $(ZLIB)
 LDLIBSS=$(PNGLIBS) $(ZLIBS)
 C=.c
@@ -38,7 +37,7 @@ E=
 all: png2pnm$(E) pnm2png$(E) png2pnm-static$(E) pnm2png-static$(E)
 
 png2pnm$(O): png2pnm$(C)
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) png2pnm$(C)
+	$(CC) -c $(CFLAGS) png2pnm$(C)
 
 png2pnm$(E): png2pnm$(O)
 	$(LD) $(LDFLAGS) -o png2pnm$(E) png2pnm$(O) $(LDLIBS) -lm
@@ -47,7 +46,7 @@ png2pnm-static$(E): png2pnm$(O)
 	$(LD) $(LDFLAGS) -o png2pnm-static$(E) png2pnm$(O) $(LDLIBSS) -lm
 
 pnm2png$(O): pnm2png$(C)
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) pnm2png$(C)
+	$(CC) -c $(CFLAGS) pnm2png$(C)
 
 pnm2png$(E): pnm2png$(O)
 	$(LD) $(LDFLAGS) -o pnm2png$(E) pnm2png$(O) $(LDLIBS) -lm

contrib/pngminus/makefile.tc3

@@ -7,8 +7,7 @@ LB=tlib
 RM=del
 CP=copy
 MODEL=l
-CPPFLAGS=-I..\libpng -I..\zlib
-CFLAGS=-O -m$(MODEL)
+CCFLAGS=-O -m$(MODEL) -I..\libpng -I..\zlib
 LDFLAGS=-m$(MODEL) -L..\libpng -L..\zlib
 C=.c
 O=.obj
@@ -20,13 +19,13 @@ E=.exe
 all: png2pnm$(E) pnm2png$(E)
 
 png2pnm$(O): png2pnm$(C)
-        $(CC) -c $(CPPFLAGS) $(CFLAGS) png2pnm$(C)
+        $(CC) -c $(CCFLAGS) png2pnm$(C)
 
 png2pnm$(E): png2pnm$(O)
         $(LD) $(LDFLAGS) png2pnm$(O) libpng$(L) zlib$(L)
 
 pnm2png$(O): pnm2png$(C)
-        $(CC) -c $(CPPFLAGS) $(CFLAGS) pnm2png$(C)
+        $(CC) -c $(CCFLAGS) pnm2png$(C)
 
 pnm2png$(E): pnm2png$(O)
         $(LD) $(LDFLAGS) pnm2png$(O) libpng$(L) zlib$(L)
@@ -36,3 +35,4 @@ clean:
         $(RM) *$(E)
 
 # End of makefile for png2pnm / pnm2png
+

contrib/pngminus/png2pnm.c

@@ -5,7 +5,8 @@
  *  version 1.0 - 1999.10.15 - First version.
  *          1.1 - 2017.04.22 - Add buffer-size check (Glenn Randers-Pehrson)
  *          1.2 - 2017.08.24 - Fix potential overflow in buffer-size check
-                               (Glenn Randers-Pehrson)
+ *                             (Glenn Randers-Pehrson)
+ *          1.3 - 2017.08.28 - Add PNGMINUS_UNUSED (Christian Hesse)
  *
  *  Permission to use, copy, modify, and distribute this software and
  *  its documentation for any purpose and without fee is hereby granted,
@@ -44,6 +45,7 @@
 #define PNG_DEBUG 0
 #endif
 
+
 #include "png.h"
 
 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
@@ -51,6 +53,14 @@
 #  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
 #endif
 
+#ifndef PNGMINUS_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely).
+ */
+#  define PNGMINUS_UNUSED(param) (void)param
+#endif
+
 /* function prototypes */
 
 int  main (int argc, char *argv[]);
@@ -443,7 +453,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
   if (png_pixels != (unsigned char*) NULL)
     free (png_pixels);
 
-  PNG_UNUSED(raw) /* to quiet a Coverity defect */
+  PNGMINUS_UNUSED(raw); /* to quiet a Coverity defect */
   return TRUE;
 
 } /* end of source */

contrib/pngminus/pnm2png.c

@@ -7,6 +7,7 @@
  *  version 1.2 - 2017.04.22 - Add buffer-size check
  *          1.3 - 2017.08.24 - Fix potential overflow in buffer-size check
  *                             (Glenn Randers-Pehrson)
+ *          1.4 - 2017.08.28 - Add PNGMINUS_UNUSED (Christian Hesse)
  *
  *  Permission to use, copy, modify, and distribute this software and
  *  its documentation for any purpose and without fee is hereby granted,
@@ -50,6 +51,15 @@
 #  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
 #endif
 
+#ifndef PNGMINUS_UNUSED
+/* Unused formal parameter warnings are silenced using the following macro
+ * which is expected to have no bad effects on performance (optimizing
+ * compilers will probably remove it entirely).
+ */
+#  define PNGMINUS_UNUSED(param) (void)param
+#endif
+
+
 /* function prototypes */
 
 int  main (int argc, char *argv[]);
@@ -376,13 +386,13 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   /* row_bytes is the width x number of channels x (bit-depth / 8) */
     row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
 
-  if ((row_bytes == 0 || (size_t)height > ((size_t)(-1))/(size_t)row_bytes)
+  if ((row_bytes == 0 || (size_t)height > ((size_t)(-1))/(size_t)row_bytes))
   {
     /* too big */ 
     return FALSE;
   }
   if ((png_pixels = (png_byte *)
-     malloc (row_bytes * height * sizeof (png_byte))) == NULL)
+     malloc ((size_t)row_bytes * (size_t)height * sizeof (png_byte))) == NULL)
     return FALSE;
 
   /* read data from PNM file */
@@ -513,7 +523,7 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   if (png_pixels != (unsigned char*) NULL)
     free (png_pixels);
 
-  PNG_UNUSED(raw) /* Quiet a Coverity defect */
+  PNGMINUS_UNUSED(raw); /* Quiet a Coverity defect */
 
   return TRUE;
 } /* end of pnm2png */

contrib/pngsuite/README

@@ -1,8 +1,8 @@
 
 pngsuite
 --------
-Copyright (c) Willem van Schaik, 1999, 2011, 2012
-Two images (ftbbn0g01.png and ftbbn0g02.png) are by Glenn Randers-Pehrson, 2012
+(c) Willem van Schaik, 1999, 2011, 2012
+Two images are by Glenn Randers-Pehrson, 2012
 
 Permission to use, copy, modify, and distribute these images for any
 purpose and without fee is hereby granted.
@@ -101,5 +101,5 @@ Testing basn6a16.png: PASS (1072 zero samples)
 libpng passes test
 
 Willem van Schaik
-<willem at schaik.com>
+<willem@schaik.com>
 October 1999

contrib/powerpc-vsx/README

@@ -1,81 +0,0 @@
-OPERATING SYSTEM SPECIFIC POWERPC DETECTION
---------------------------------------------
-
-Detection of the ability to execute POWERPC on processor requires
-operating system support.  (The information is not available in user mode.)
-
-Currently only this feature is supported only for linux platform.
-
-HOW TO USE THIS
----------------
-
-This directory contains C code fragments that can be included in powerpc/powerpc_init.c
-by setting the macro PNG_POWERPC_VSX_FILE to the file name in "" or <> at build
-time.  This setting is not recorded in pnglibconf.h and can be changed simply by
-rebuilding arm/arm_init.o with the required macro definition.
-
-For any of this code to be used the POWERPC code must be enabled and run time
-checks must be supported.  I.e.:
-
-#if PNG_POWERPC_VSX_OPT > 0
-#ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED
-
-This is done in a 'configure' build by passing configure the argument:
-
-   --enable-powerpc-vsx=check
-
-FILE FORMAT
------------
-
-Each file documents its testing status as of the last time it was tested (which
-may have been a long time ago):
-
-STATUS: one of:
-   SUPPORTED: This indicates that the file is included in the regularly
-         performed test builds and bugs are fixed when discovered.
-   COMPILED: This indicates that the code did compile at least once.  See the
-         more detailed description for the extent to which the result was
-         successful.
-   TESTED: This means the code was fully compiled into the libpng test programs
-         and these were run at least once.
-
-BUG REPORTS: an email address to which to send reports of problems
-
-The file is a fragment of C code. It should not define any 'extern' symbols;
-everything should be static.  It must define the function:
-
-static int png_have_vsx(png_structp png_ptr);
-
-That function must return 1 if ARM NEON instructions are supported, 0 if not.
-It must not execute png_error unless it detects a bug.  A png_error will prevent
-the reading of the PNG and in the future, writing too.
-
-BUG REPORTS
------------
-
-If you mail a bug report for any file that is not SUPPORTED there may only be
-limited response.  Consider fixing it and sending a patch to fix the problem -
-this is more likely to result in action.
-
-CONTRIBUTIONS
--------------
-
-You may send contributions of new implementations to
-png-mng-implement@sourceforge.net.  Please write code in strict C90 C where
-possible.  Obviously OS dependencies are to be expected.  If you submit code you
-must have the authors permission and it must have a license that is acceptable
-to the current maintainer; in particular that license must permit modification
-and redistribution.
-
-Please try to make the contribution a single file and give the file a clear and
-unambiguous name that identifies the target OS.  If multiple files really are
-required put them all in a sub-directory.
-
-You must also be prepared to handle bug reports from users of the code, either
-by joining the png-mng-implement mailing list or by providing an email for the
-"BUG REPORTS" entry or both.  Please make sure that the header of the file
-contains the STATUS and BUG REPORTS fields as above.
-
-Please list the OS requirements as precisely as possible.  Ideally you should
-also list the environment in which the code has been tested and certainly list
-any environments where you suspect it might not work.

contrib/powerpc-vsx/linux.c

@@ -1,57 +0,0 @@
-/* contrib/powerpc-vsx/linux.c
- *
- * Copyright (c) 2017 Glenn Randers-Pehrson
- * Written by Vadim Barkov, 2017.
- * Last changed in libpng 1.6.29 [March 16, 2017]
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * STATUS: TESTED
- * BUG REPORTS: png-mng-implement@sourceforge.net
- *
- * png_have_vsx implemented for Linux by reading the widely available
- * pseudo-file /proc/cpuinfo. 
- *
- * This code is strict ANSI-C and is probably moderately portable; it does
- * however use <stdio.h> and it assumes that /proc/cpuinfo is never localized.
- */
-
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include "png.h"
-
-#ifndef MAXLINE
-#  define MAXLINE 1024
-#endif
-
-static int
-png_have_vsx(png_structp png_ptr)
-{
-   FILE *f;
-
-   const char *string = "altivec supported";
-   char input[MAXLINE];
-   char *token = NULL;
-
-   PNG_UNUSED(png_ptr)
-
-   f = fopen("/proc/cpuinfo", "r");
-   if (f != NULL)
-   {
-      memset(input,0,MAXLINE);
-      while(fgets(input,MAXLINE,f) != NULL)
-      {
-         token = strstr(input,string);
-         if(token != NULL)
-            return 1;
-      }
-   }
-#ifdef PNG_WARNINGS_SUPPORTED
-   else
-      png_warning(png_ptr, "/proc/cpuinfo open failed");
-#endif
-   return 0;
-}

contrib/powerpc-vsx/linux_aux.c

@@ -1,36 +0,0 @@
-/* contrib/powerpc-vsx/linux_aux.c
- *
- * Copyright (c) 2017 Glenn Randers-Pehrson
- * Written by Vadim Barkov, 2017.
- * Last changed in libpng 1.6.29 [March 16, 2017]
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * STATUS: TESTED
- * BUG REPORTS: png-mng-implement@sourceforge.net
- *
- * png_have_vsx implemented for Linux by using the auxiliary vector mechanism.
- *
- * This code is strict ANSI-C and is probably moderately portable; it does
- * however use <stdio.h> and it assumes that /proc/cpuinfo is never localized.
- */
-
-#include "sys/auxv.h"
-#include "png.h"
-
-static int
-png_have_vsx(png_structp png_ptr)
-{
-
-   const unsigned long auxv = getauxval( AT_HWCAP );
-
-   PNG_UNUSED(png_ptr)
-
-   if(auxv & (PPC_FEATURE_HAS_ALTIVEC|PPC_FEATURE_HAS_VSX ))
-      return 1;
-   else
-      return 0;
-}
-

contrib/testpngs/makepngs.sh

@@ -5,7 +5,7 @@
 
 # Copyright (c) 2015 John Cunningham Bowler
 
-# Last changed in libpng 1.6.20 [December 3, 2015]
+# Last changed in libpng 1.7.0 [(PENDING RELEASE)]
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -15,10 +15,22 @@
 # ones that extend the code-coverage of libpng from the existing test files in
 # contrib/pngsuite.
 test -n "$MAKEPNG" || MAKEPNG=./makepng
+if test "$1" = "-v"
+then
+   verbose=1
+   shift
+else
+   verbose=
+fi
+what="$1"
+shift
+cmdline="$@"
 opts=
 
 mp(){
-   ${MAKEPNG} $opts $1 "$3" "$4" "$3-$4$2.png"
+   test -n "$verbose" &&
+      echo ${MAKEPNG} $opts $cmdline $1 "$3" "$4" "$3-$4$2.png"
+   ${MAKEPNG} $opts $cmdline $1 "$3" "$4" "$3-$4$2.png"
 }
 
 mpg(){
@@ -39,7 +51,7 @@ mptrans(){
    fi
 }
 
-case "$1" in
+case "$what" in
    --small)
       opts="--small";;&
 
@@ -72,19 +84,8 @@ case "$1" in
       done;;
 
    --coverage)
-      # Comments below indicate cases known to be required and not duplicated
-      # in other (required) cases; the aim is to get a minimal set that gives
-      # the maxium code coverage.
-      mpg none gray-alpha 8 # required: code coverage, sRGB opaque component
-      mpg none palette 8 # required: basic palette read
-      mpg 1.8 gray 2 # required: tests gamma threshold code
-      mpg 1.8 palette 2 # required: code coverage
-      mpg 1.8 palette 4 # required: code coverage
-      mpg 1.8 palette 8 # error limits only
-      mpg linear palette 8 # error limits only
-      mpg linear rgb-alpha 16 # error limits only
-      mpg sRGB palette 1 # required: code coverage
-      mpg sRGB rgb-alpha 16 # required: code coverage: pngread.c:2422 untested
+      # Extra images made to improve code coverage:
+      ${MAKEPNG} --insert sBIT 1 --tRNS gray 2 gray-2-sBIT-tRNS.png
       :;;
 
    *)

contrib/tools/chunkhash.c

@@ -0,0 +1,437 @@
+/* chunkhash.c -- build a perfect hash code for the chunk names on stdin.
+ *
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2014.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Feed this program all the known chunks that libpng must recognize.  It will
+ * generate an appropriate hash key for the macro in pngpriv.h  To generate the
+ * list of chunks currently defined in png.h do this:
+ *
+ *    sed -n -e 's/^#define png_\(....\) PNG_U32.*$/\1/p' png.h
+ *
+ * An alternative to using this program is to pipe the output of the above
+ * through gperf, however the code generated by perf is somewhat more verbose
+ * and it doesn't generate as good a result (however it's a heck of a lot faster
+ * than this program!)
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <png.h> /* for the libpng types for this platform */
+
+/* The machine generated file is checked in, so this works and it obtains the
+ * definition of the PNG_CHUNK_HASH macro.  To change this definition only ever
+ * alter the strings below!
+ */
+#include "chunkhash.h"
+
+/* The best_ variables are local variables defined in the functions below.  When
+ * used in libpng code, however, they are just constants.
+ */
+#define PNG_CHUNK_HASH_MASK best_mask
+#define PNG_CHUNK_HASH_C0 best_c[0]
+#define PNG_CHUNK_HASH_C1 best_c[1]
+#define PNG_CHUNK_HASH_C2 best_c[2]
+#define PNG_CHUNK_HASH_C3 best_c[3]
+
+/* These strings contain the C text to copy into the new version of
+ * contrib/tools/chunkhash.c
+ */
+static const char *strings[] = {
+"/* chunkhash.h -- a perfect hash code for the chunk names in png.h",
+" *",
+" * Last changed in libpng 1.7.0 [(PENDING RELEASE)]",
+" *",
+" * THIS IS A MACHINE GENERATED FILE.  See contrib/tools/chunkhash.c for",
+" * copyright and other information.",
+" *",
+" * USAGE:  To include the PNG_CHUNK_HASH macro and associated definitions:",
+" *",
+" * #define PNG_CHUNKHASH_DEFS",
+" * #include \"contrib/tools/chunkhash.h\"",
+" *",
+" * To define the png_chunk_hash array used by the macro:",
+" *",
+" * #define PNG_CHUNKHASH_CODE",
+" * #include \"contrib/tools/chunkhash.h\"",
+" *",
+" * One or both of the defines must be given except when building chunkhash",
+" * itself.",
+" */",
+"#ifdef PNG_CHUNKHASH_DEFS",
+"#ifndef PNG_CHUNKHASH_H",
+"#define PNG_CHUNKHASH_H",
+"/* A perfect hash code - returns a value 0..(PNG_KNOWN_CHUNK_COUNT-1) and is",
+" * generated by the ridiculously simple program in contrib/tools/chunkhash.c",
+" *",
+" * The hash code used here multiplies each byte by a different constant to",
+" * return a single number:",
+" *",
+" *    b0 * c[0] + b1 * [c1] + b2 * c[2] + b3 * c[3]",
+" *",
+" * The values of the constants are found by search using the a table of",
+" * primes, including 0, and may be (in fact are at present) 0 for some of the",
+" * bytes, the compiler is expected to optimize multiply by zero, or one!",
+" *",
+" * The lookup table reduces the sparse result of the hash calculation to the",
+" * correct index values.  The chunks are indexed in the string order of the",
+" * png_uint_32 chunk names.",
+" */",
+0, /* HEADER definitions go here */
+"",
+"extern const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1];",
+"#endif /* !PNG_CHUNKHASH_H */",
+"#endif /* PNG_CHUNKHASH_DEFS */",
+"",
+"#ifndef PNG_CHUNK_HASH",
+"#define PNG_CHUNK_HASH(chunk) (png_chunk_hash[PNG_CHUNK_HASH_MASK & (\\",
+"      ((chunk) >> 24) * PNG_CHUNK_HASH_C0 +\\",
+"      ((chunk) >> 16) * PNG_CHUNK_HASH_C1 +\\",
+"      ((chunk) >>  8) * PNG_CHUNK_HASH_C2 +\\",
+"      ((chunk)      ) * PNG_CHUNK_HASH_C3)])",
+"#endif",
+"",
+"#ifdef PNG_CHUNKHASH_CODE",
+"#ifndef PNG_CHUNKHASH_C",
+"#define PNG_CHUNKHASH_C",
+"const png_byte png_chunk_hash[PNG_CHUNK_HASH_MASK+1] = {",
+0, /* png.c definitions go here */
+"};",
+"#endif /* !PNG_CHUNKHASH_C */",
+"#endif /* PNG_CHUNKHASH_CODE */",
+0 /* end of file */
+};
+
+#define CHUNK_COUNT_MAX 32
+   /* If necessary this is easy to increase; just don't use a png_uint_32
+    * bitmask below, however it doesn't seem likely that the limit will be hit
+    * any time soon.
+    */
+
+static const png_byte
+chunk_hash[256] =
+{
+   0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
+   22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+   41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
+   60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,
+   79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97,
+   98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113,
+   114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128,
+   129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143,
+   144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158,
+   159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173,
+   174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188,
+   189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203,
+   204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218,
+   219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233,
+   234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248,
+   249, 250, 251, 252, 253, 254, 255
+};
+
+static void
+error(const char *string)
+{
+   fprintf(stderr, "chunkhash: %s\n", string);
+   exit(1);
+}
+
+/* Return a hash code for the given chunk; this is the same as the pngpriv.h
+ * macro, but parameterized.  The names of the parameters have to be chosen to
+ * match the above #defines.
+ */
+static png_uint_32
+test_hash(png_uint_32 chunk, const unsigned int *best_c, png_uint_32 best_mask)
+{
+#  define png_chunk_hash chunk_hash /* prevents lookup */
+      return PNG_CHUNK_HASH(chunk);
+#  undef png_chunk_hash
+}
+
+static void
+print_chunks(const png_uint_32 *chunks, unsigned int nchunks, png_uint_32 first,
+   png_uint_32 last, const unsigned int *best_c, png_uint_32 best_mask,
+   const png_byte *lut)
+{
+   /* 'last' is the last code to print plus 1, this is used to detect duplicates
+    * (which should not happen - if there are any it's an internal error!)
+    */
+   if (nchunks > 0)
+   {
+      /* Recursive algorithm; find the hash code of the next chunk, then print
+       * all remaining chunks with codes in the range first..code (including
+       * duplicates) and after print all remaining chunks with codes in the
+       * range (code+1)..last
+       */
+      const png_uint_32 chunk = *chunks++;
+#     define png_chunk_hash lut
+         const png_uint_32 code = PNG_CHUNK_HASH(chunk);
+#     undef png_chunk_hash
+
+      --nchunks;
+
+      /* The code might be out of the print range */
+      if (code >= first && code <= last)
+      {
+         if (code >= first) /* not time yet */
+            print_chunks(chunks, nchunks, first, code, best_c, best_mask, lut);
+
+         printf("#define PNG_CHUNK_%c%c%c%c_TAG %lu%s\n", (char)(chunk>>24),
+            (char)(chunk>>16), (char)(chunk>>8), (char)chunk,
+            (unsigned long)code, code == last ? " /* DUPLICATE */" : "");
+
+         if (code < last) /* still some to go */
+            print_chunks(chunks, nchunks, code+1, last, best_c, best_mask, lut);
+      }
+
+      else
+         print_chunks(chunks, nchunks, first, last, best_c, best_mask, lut);
+   }
+}
+
+static unsigned int primes[] =
+{
+   0, 1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67,
+   71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149,
+   151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229,
+   233, 239, 241, 251
+};
+
+#define NPRIMES ((sizeof primes)/(sizeof primes[0]))
+
+int
+main(void)
+{
+   /* Stdin should just contain chunk names, one per line */
+   png_uint_32 best_mask;
+   unsigned int best_c[4];
+   png_uint_32 chunks[CHUNK_COUNT_MAX];
+   png_byte known_chunk_count;
+
+   /* Not required; stop GCC whining: */
+   memset(best_c, 0xab, sizeof best_c);
+   best_mask = 0x12345678;
+
+   {
+      png_uint_32 this_chunk = 0;
+      png_byte n_chunks = 0;
+
+      for (;;)
+      {
+         int ch = getchar();
+
+         if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z'))
+         {
+            if (this_chunk > 0xffffffU)
+               error("chunk name too long");
+
+            this_chunk = (this_chunk << 8) + (unsigned)ch;
+         }
+
+         else
+         {
+            if (this_chunk > 0)
+            {
+               if (this_chunk <= 0xffffffU)
+                  error("chunk name too short");
+
+               if (n_chunks >= CHUNK_COUNT_MAX)
+                  error("too many chunks (check CHUNK_COUNT_MAX)");
+
+               chunks[n_chunks++] = this_chunk;
+               this_chunk = 0;
+            }
+         }
+
+         if (ch < 0)
+            break;
+      }
+
+      /* 22 is the number of chunks currently defined (excluding fRAc), at any
+       * time it should also be in PNG_KNOWN_CHUNK_COUNT, but this run of
+       * chunkhash may be trying to add a chunk so allow bigger numbers.
+       */
+#     ifdef PNG_KNOWN_CHUNK_COUNT
+#        define CHUNK_COUNT_MIN PNG_KNOWN_CHUNK_COUNT
+#     else
+#        define CHUNK_COUNT_MIN 26
+#     endif
+      if (n_chunks < CHUNK_COUNT_MIN)
+         error("too few chunks (expecting at least 26)");
+
+      known_chunk_count = n_chunks;
+   }
+
+   /* Exhaustive search of the hash parameters - in fact this isn't very slow at
+    * all.
+    */
+   {
+      unsigned int i1, c_zero = 0, c_one = 0;
+
+      for (i1=0; i1<NPRIMES; ++i1)
+      {
+         unsigned int i2;
+         unsigned int c[4];
+
+         fprintf(stderr, "TEST: %u\n", primes[i1]);
+         c[0] = primes[i1];
+
+         for (i2=0; i2<NPRIMES; ++i2)
+         {
+            unsigned int i3;
+
+            c[1] = primes[i2];
+
+            for (i3=0; i3<NPRIMES; ++i3)
+            {
+               unsigned int i4;
+
+               c[2] = primes[i3];
+
+               for (i4=0; i4<NPRIMES; ++i4)
+               {
+                  unsigned int i;
+                  png_uint_32 hash_mask = 0xffU;
+                  png_uint_32 hashes[CHUNK_COUNT_MAX];
+
+                  c[3] = primes[i4];
+
+                  while (hash_mask > 0xfU)
+                  {
+                     for (i=0; i<known_chunk_count; ++i)
+                     {
+                        unsigned int j;
+                        png_uint_32 hash = test_hash(chunks[i], c, hash_mask);
+
+                        for (j=0; j<i; ++j) if (hashes[j] == hash) goto next_i4;
+
+                        hashes[i] = hash;
+                     }
+
+                     hash_mask >>= 1;
+                  }
+
+               next_i4:
+                  if (hash_mask < 0xffU)
+                  {
+                     /* This worked */
+                     unsigned int best, c0 = 0, c1 = 0;
+
+                     hash_mask <<= 1;
+                     hash_mask += 1;
+
+                     for (i=0; i<4; ++i)
+                     {
+                        if (c[i] == 0)
+                           ++c0;
+
+                        else if (c[i] == 1)
+                           ++c1;
+                     }
+
+                     if (hash_mask == best_mask)
+                        best = (c0 > c_zero) || (c0 == c_zero && c1 > c_one);
+
+                     else
+                        best = (hash_mask < best_mask);
+
+                     if (best)
+                     {
+                        fprintf(stderr, "{%u,%u,%u,%u} & 0x%lx\n",
+                           c[0], c[1], c[2], c[3],
+                           (unsigned long)hash_mask);
+
+                        c_zero = c0;
+                        c_one = c1;
+                        best_mask = hash_mask;
+                        memcpy(best_c, c, sizeof best_c);
+                     }
+                  }
+               } /* i4 */
+            } /* i3 */
+         } /* i2 */
+      } /* i1 */
+   }
+
+   /* Calculate the LUT (png_chunk_hash) */
+   {
+      png_byte b;
+      png_byte lut[256];
+
+      /* A failure returns PNG_KNOWN_CHUNK_COUNT: */
+      memset(lut, known_chunk_count, sizeof lut);
+
+      for (b=0; b<known_chunk_count; ++b)
+         lut[test_hash(chunks[b], best_c, best_mask)] = b;
+
+      /* Validate the pngpriv.h hash function. */
+#     define png_chunk_hash lut
+         {
+            unsigned int i;
+
+            for (i=0; i<known_chunk_count; ++i)
+            {
+               png_uint_32 chunk = chunks[i];
+
+               if (PNG_CHUNK_HASH(chunk) != i)
+                  error("internal error: hash didn't work!");
+            }
+         }
+#     undef lut
+
+      /* Print all the results, first the stuff for pngpriv.h */
+      {
+         unsigned int i = 0;
+
+         while (strings[i] != 0)
+            puts(strings[i++]);
+
+         printf("#define PNG_CHUNK_HASH_MASK 0x%lxU\n",
+            (unsigned long)best_mask);
+         printf("#define PNG_CHUNK_HASH_C0 %u\n", best_c[0]);
+         printf("#define PNG_CHUNK_HASH_C1 %u\n", best_c[1]);
+         printf("#define PNG_CHUNK_HASH_C2 %u\n", best_c[2]);
+         printf("#define PNG_CHUNK_HASH_C3 %u\n", best_c[3]);
+
+         /* Print the hash codes of all the chunks */
+         putchar('\n');
+         print_chunks(chunks, known_chunk_count, 0, 0xffffffff, best_c,
+            best_mask, lut);
+         putchar('\n');
+         printf("#define PNG_KNOWN_CHUNK_COUNT %u\n", known_chunk_count);
+
+         while (strings[++i] != 0)
+            puts(strings[i]);
+
+         /* Now print the LUT */
+         fputs("   ", stdout);
+         {
+            unsigned int j;
+
+            for (j=0; j<=best_mask; ++j)
+            {
+               printf("%d", lut[j]);
+
+               if ((j % 16) == 15 && j < best_mask)
+                  printf(",\n   ");
+
+               else if (j < best_mask)
+                  printf(", ");
+
+               else
+                  printf("\n");
+            }
+         }
+
+         /* And the trailing text */
+         while (strings[++i] != 0)
+            puts(strings[i]);
+      }
+   }
+
+   exit(0);
+}

contrib/tools/chunkhash.h

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

contrib/tools/dynamic-range.c

@@ -0,0 +1,208 @@
+/* dynamic-range.c
+ *
+ * Last changed in libpng 1.7.0
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2015
+ * 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.
+ *
+ * Find the dynamic range of a given gamma encoding given a (linear) precision
+ * and a maximum number of encoded values.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <float.h>
+#include <math.h>
+#include <assert.h>
+
+double range(unsigned int steps, double factor, double gamma)
+{
+   return pow((steps * (pow(factor, 1/gamma) - 1)), gamma);
+}
+
+double max_range_gamma(unsigned int steps, double factor, double *max_range,
+      double glo, double rlo, double gmid, double rmid, double ghi, double rhi)
+{
+   /* Given three values which contain a peak value (so rmid > rlo and rmid >
+    * rhi) find the peak by repeated division of the range.  The algorithm is to
+    * find the range for two gamma values mid-way between the two pairs
+    * (glo,gmid), (ghi,gmid) then find the max; this gives us a new glo/ghi
+    * which must be half the distance apart of the previous pair.
+    */
+   double gammas[5];
+   double ranges[5];
+
+   gammas[0] = glo;  ranges[0] = rlo;
+   gammas[2] = gmid; ranges[2] = rmid;
+   gammas[4] = ghi;  ranges[4] = rhi;
+
+   for (;;)
+   {
+      int i, m;
+
+      ranges[1] = range(steps, factor, gammas[1] = (gammas[0]+gammas[2])/2);
+      ranges[3] = range(steps, factor, gammas[3] = (gammas[2]+gammas[4])/2);
+
+      for (m=1, i=2; i<4; ++i)
+         if (ranges[i] >= ranges[m])
+            m = i;
+
+      assert(gammas[0] < gammas[m] && gammas[m] < gammas[4]);
+      assert(ranges[0] < ranges[m] && ranges[m] > ranges[4]);
+
+      gammas[0] = gammas[m-1]; ranges[0] = ranges[m-1];
+      gammas[4] = gammas[m+1]; ranges[4] = ranges[m+1];
+      gammas[2] = gammas[m];   ranges[2] = ranges[m];
+
+      if (((gammas[4] - gammas[0])/gammas[2]-1) < 3*DBL_EPSILON ||
+          ((ranges[2] - ranges[0])/ranges[2]-1) < 6*DBL_EPSILON)
+      {
+         *max_range = ranges[2];
+         return gammas[2];
+      }
+   }
+}
+
+double best_gamma(unsigned int values, double precision, double *best_range)
+{
+   /* The 'guess' gamma value is determined by the following formula, which is
+    * itself derived from linear regression using values returned by this
+    * program:
+    */
+   double gtry = values * precision / 2.736;
+   double rtry;
+
+   /* 'values' needs to be the number of steps after the first, we have to
+    * reserve the first value, 0, for 0, so subtract 2 from values.  precision
+    * must be adjusted to the step factor.
+    */
+   values -= 2U;
+   precision += 1;
+   rtry = range(values, precision, gtry);
+
+   /* Now find two values either side of gtry with a lower range. */
+   {
+      double glo, ghi, rlo, rhi, gbest, rbest;
+
+      glo = gtry;
+      do
+      {
+         glo *= 0.9;
+         rlo = range(values, precision, glo);
+      }
+      while (rlo >= rtry);
+
+      ghi = gtry;
+      do
+      {
+         ghi *= 1.1;
+         rhi = range(values, precision, ghi);
+      }
+      while (rhi >= rtry);
+
+      gbest = max_range_gamma(values, precision, &rbest,
+            glo, rlo, gtry, rtry, ghi, rhi);
+
+      *best_range = rbest / precision;
+      return gbest;
+   }
+}
+
+double linear_regression(double precision, double *bp)
+{
+   unsigned int values, count = 0;
+   double g_sum = 0, g2_sum = 0, v_sum = 0, v2_sum = 0, gv_sum = 0;
+
+   /* Perform simple linear regression to get:
+    *
+    *    gamma = a + b.values
+    */
+   for (values = 128; values < 65536; ++values, ++count)
+   {
+      double range;
+      double gamma = best_gamma(values, precision, &range);
+
+      g_sum += gamma;
+      g2_sum += gamma * gamma;
+      v_sum += values;
+      v2_sum += values * (double)values;
+      gv_sum += gamma * values;
+      /* printf("%u %g %g\n", values, gamma, range); */
+   }
+
+   g_sum /= count;
+   g2_sum /= count;
+   v_sum /= count;
+   v2_sum /= count;
+   gv_sum /= count;
+
+   {
+      double b = (gv_sum - g_sum * v_sum) / (v2_sum - v_sum * v_sum);
+      *bp = b;
+      return g_sum - b * v_sum;
+   }
+}
+
+int
+main(int argc, const char **argv)
+{
+   double precision = argc == 2 ? atof(argv[1]) : 0;
+
+   /* Perform a second linear regression here on b:
+    *
+    *    b = bA + bB * precision
+    */
+   if (precision == 0)
+   {
+      double b_sum = 0, b2_sum = 0, p_sum = 0, p2_sum = 0, bp_sum = 0,
+             a_sum = 0, count = 0;
+
+      for (precision = .001; precision <= 0.01; precision += .001, count += 1)
+      {
+         double b;
+         double a = linear_regression(precision, &b);
+
+         b_sum += b;
+         b2_sum += b * b;
+         p_sum += precision;
+         p2_sum += precision * precision;
+         bp_sum += b * precision;
+         a_sum += a;
+      }
+
+      b_sum /= count;
+      b2_sum /= count;
+      p_sum /= count;
+      p2_sum /= count;
+      bp_sum /= count;
+      a_sum /= count;
+
+      {
+         double bB = (bp_sum - b_sum * p_sum) / (p2_sum - p_sum * p_sum);
+         double bA = b_sum - bB * p_sum;
+
+         printf("a = %g, b = %g + precision/%g\n", a_sum, bA, 1/bB);
+      }
+   }
+
+   else
+   {
+      unsigned int bits;
+      double b;
+      double a = linear_regression(precision, &b);
+      printf("precision %g: gamma = %g + values*%g\n", precision, a, b);
+
+      /* For information, given a precision: */
+      for (bits=7U; bits <= 16U; ++bits)
+      {
+         unsigned int values = 1U<<bits;
+         double gamma = values*precision/2.736;
+         double r = range(values-2U, 1+precision, gamma);
+
+         printf("bits: %u, gamma: %g, range: 1:%g\n", bits, gamma, r);
+      }
+   }
+
+   return 0;
+}

contrib/tools/genpng.c

@@ -1,8 +1,7 @@
 /*- genpng
  *
  * COPYRIGHT: Written by John Cunningham Bowler, 2015.
- * Revised by Glenn Randers-Pehrson, 2017, to add buffer-size check.
- * To the extent possible under law, the authors have waived all copyright and
+ * 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.
  *
@@ -784,19 +783,6 @@ main(int argc, const char **argv)
          return 1;
       }
 
-#if 1
-     /* TO do: determine whether this guard against overflow is necessary.
-      * This comment in png.h indicates that it should be safe: "libpng will
-      * refuse to process an image where such an overflow would occur", but
-      * I don't see where the image gets rejected when the buffer is too
-      * large before the malloc is attempted.
-      */
-      if (image.height > ((size_t)(-1))/(8*image.width)) {
-         fprintf(stderr, "genpng: image buffer would be too big");
-         return 1;
-      }
-#endif
-
       /* Create the buffer: */
       buffer = malloc(PNG_IMAGE_SIZE(image));
 

contrib/tools/pngfix.c

@@ -1,7 +1,8 @@
 /* pngfix.c
  *
- * Last changed in libpng 1.6.31 [July 27, 2017]
- * Copyright (c) 2014-2017 John Cunningham Bowler
+ * Copyright (c) 2014-2016 John Cunningham Bowler
+ *
+ * Last changed in libpng 1.6.26 [October 20, 2016]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -2415,7 +2416,7 @@ zlib_advance(struct zlib *zlib, png_uint_32 nbytes)
                   endrc = ZLIB_TOO_FAR_BACK;
                   break;
                }
-               /* FALLTHROUGH */
+               /* FALL THROUGH */
 
             default:
                zlib_message(zlib, 0/*stream error*/);
@@ -2569,7 +2570,7 @@ zlib_run(struct zlib *zlib)
                   list->lengths[i] -= zlib->extra_bytes;
                   list->count = i+1;
                   zlib->idat->idat_list_tail = list;
-                  /* FALLTHROUGH */
+                  /* FALL THROUGH */
 
                default:
                   return rc;
@@ -2672,7 +2673,7 @@ zlib_check(struct file *file, png_uint_32 offset)
             /* Truncated stream; unrecoverable, gets converted to ZLIB_FATAL */
             zlib.z.msg = PNGZ_MSG_CAST("[truncated]");
             zlib_message(&zlib, 0/*expected*/);
-            /* FALLTHROUGH */
+            /* FALL THROUGH */
 
          default:
             /* Unrecoverable error; skip the chunk; a zlib_message has already
@@ -3340,7 +3341,7 @@ read_callback(png_structp png_ptr, png_bytep buffer, size_t count)
                if (file->state != STATE_IDAT && length > 0)
                   setpos(chunk);
             }
-            /* FALLTHROUGH */
+            /* FALL THROUGH */
 
          default:
             assert(chunk != NULL);

contrib/tools/scale.c

@@ -0,0 +1,238 @@
+/* Given a target range and a source range work out an expression to scale from
+ * the source to the target of the form:
+ *
+ *    (number * mult + add)>>16
+ *
+ * The command arguments are:
+ *
+ *    scale target source
+ *
+ * and the program works out a pair of numbers, mult and add, that evaluate:
+ *
+ *          number * target
+ *   round( --------------- )
+ *              source
+ *
+ * exactly for number in the range 0..source
+ */
+#define _ISOC99_SOURCE 1
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <math.h>
+
+static double minerr;
+static unsigned long minmult, minadd, minshift;
+static long mindelta;
+
+static int
+test(unsigned long target, unsigned long source, unsigned long mult,
+   long add, unsigned long shift, long delta)
+{
+   unsigned long i;
+   double maxerr = 0;
+   double rs = (double)target/source;
+
+   for (i=0; i<=source; ++i)
+   {
+      unsigned long t = i*mult+add;
+      double err = fabs((t >> shift) - i*rs);
+
+      if (err > minerr)
+         return 0;
+
+      if (err > maxerr)
+         maxerr = err;
+   }
+
+   if (maxerr < minerr)
+   {
+      minerr = maxerr;
+      minmult = mult;
+      minadd = add;
+      minshift = shift;
+      mindelta = delta;
+   }
+
+   return maxerr < .5;
+}
+
+static int
+dotest(unsigned long target, unsigned long source, unsigned long mult,
+   long add, unsigned long shift, long delta, int print)
+{
+   if (test(target, source, mult, add, shift, delta))
+   {
+      if (print & 4)
+         printf("      {%11lu,%6ld /* >>%lu */ }, /* %lu/%lu */\n",
+            mult, add, shift, target, source);
+
+      else if (print & 2)
+         printf("      {%11lu,%6ld,%3lu }, /* %lu/%lu */\n",
+            mult, add, shift, target, source);
+
+      else if (print)
+         printf("number * %lu/%lu = (number * %lu + %ld) >> %lu [delta %ld]\n",
+            target, source, mult, add, shift, delta);
+
+      return 1;
+   }
+
+   return 0;
+}
+
+static int
+find(unsigned long target, unsigned long source, int print, int fixshift)
+{
+   unsigned long shift = 0;
+   unsigned long shiftlim = 0;
+
+   /* In the final math the sum is at most (source*mult+add) >> shift, so:
+    *
+    *    source*mult+add < 1<<32
+    *    mult < (1<<32)/source
+    *
+    * but:
+    *
+    *    mult = (target<<shift)/source
+    *
+    * so:
+    *
+    *    (target<<shift) < (1<<32)
+    */
+   if (fixshift < 0)
+      while ((target<<shiftlim) < 0x80000000U) ++shiftlim;
+
+   else
+      shift = shiftlim = (unsigned long)fixshift;
+
+   minerr = 1E8;
+
+   for (; shift<=shiftlim; ++shift)
+   {
+      unsigned long mult = ((target<<shift) + (source>>1)) / source;
+      long delta;
+      long limit = 1; /* seems to be sufficient */
+      long add, start, end;
+
+      end = 1<<shift;
+      start = -end;
+
+      for (add=start; add<=end; ++add)
+         if (dotest(target,source,mult,add,shift,0,print))
+            return 1;
+
+      for (delta=1; delta<=limit; ++delta)
+      {
+#        if 0
+            fprintf(stderr, "%lu/%lu: shift %lu, delta %lu\n", target, source,
+               shift, delta);
+#        endif
+
+         for (add=start; add<=end; ++add)
+         {
+            if (dotest(target, source, mult-delta, add, shift, -delta, print))
+               return 1;
+
+            if (dotest(target, source, mult+delta, add, shift, delta, print))
+               return 1;
+         }
+      }
+   }
+
+   if (print & 4)
+      printf("      {%11lu,%6ld /* >>%lu */ }, /* %lu/%lu ERROR: .5+%g*/\n",
+         minmult, minadd, minshift, target, source, minerr-.5);
+
+   else if (print & 2)
+      printf("      {%11lu,%6ld,%3lu }, /* %lu/%lu ERROR: .5+%g*/\n",
+         minmult, minadd, minshift, target, source, minerr-.5);
+
+   else if (print)
+      printf(
+         "number * %lu/%lu ~= (number * %lu + %ld) >> %lu +/-.5+%g [delta %ld]\n",
+         target, source, minmult, minadd, minshift, minerr-.5, mindelta);
+
+   return 0;
+}
+
+static void
+usage(const char *prog)
+{
+   fprintf(stderr,
+      "usage: %s {--denominator|--maxshift|--code} target {source}\n"
+      " For each 'source' prints 'mult' and 'add' such that:\n\n"
+      "   (number * mult + add) >> 16 = round(number*target/source)\n\n"
+      " for all integer values of number in the range 0..source.\n\n"
+      " --denominator: swap target and source (specify a single source first\n"
+      "                and follow with multiple targets.)\n"
+      "    --maxshift: find the lowest shift value that works for all the\n"
+      "                repeated 'source' values\n"
+      "        --code: output C code for array/structure initialization\n",
+      prog);
+   exit(1);
+}
+
+int
+main(int argc, const char **argv)
+{
+   int i, err = 0, maxshift = 0, firstsrc = 1, code = 0, denominator = 0;
+   unsigned long target, shift = 0;
+
+   while (argc > 1)
+   {
+      if (strcmp(argv[firstsrc], "--maxshift") == 0)
+      {
+         maxshift = 1;
+         ++firstsrc;
+      }
+
+      else if (strcmp(argv[firstsrc], "--code") == 0)
+      {
+         code = 1;
+         ++firstsrc;
+      }
+
+      else if (strcmp(argv[firstsrc], "--denominator") == 0)
+      {
+         denominator = 1;
+         ++firstsrc;
+      }
+
+      else
+         break;
+   }
+
+
+   if (argc < 2+firstsrc)
+      usage(argv[0]);
+
+   target = strtoul(argv[firstsrc++], 0, 0);
+   if (target == 0) usage(argv[0]);
+
+   for (i=firstsrc; i<argc; ++i)
+   {
+      unsigned long source = strtoul(argv[i], 0, 0);
+
+      if (source == 0) usage(argv[0]);
+
+      if (!find(denominator ? source : target, denominator ? target : source,
+         maxshift ? 0 : 1+code, -1))
+         err = 1;
+
+      if (minshift > shift) shift = minshift;
+   }
+
+   if (maxshift) for (i=firstsrc; i<argc; ++i)
+   {
+      unsigned long source = strtoul(argv[i], 0, 0);
+
+      if (!find(denominator ? source : target, denominator ? target : source,
+         code ? 4 : 1, shift))
+         err = 1;
+   }
+
+   /* Just an exit code - the printout above lists the problem */
+   return err;
+}

contrib/visupng/PngFile.c

@@ -2,7 +2,7 @@
  *  PNGFILE.C -- Image File Functions
  *-------------------------------------
  *
- * Copyright 2000,2017 Willem van Schaik.
+ * Copyright 2000, Willem van Schaik.
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -236,10 +236,6 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
             free (pbImageData);
             pbImageData = NULL;
         }
-        if ((*piHeight) > ((size_t)(-1))/ulRowBytes) {
-        {
-            png_error(png_ptr, "Visual PNG: image is too big");
-        }
         if ((pbImageData = (png_byte *) malloc(ulRowBytes * (*piHeight)
                             * sizeof(png_byte))) == NULL)
         {

contrib/visupng/VisualPng.c

@@ -2,7 +2,7 @@
  *  VisualPng.C -- Shows a PNG image
  *------------------------------------
  *
- * Copyright 2000,2017 Willem van Schaik.
+ * Copyright 2000, Willem van Schaik.
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -726,10 +726,6 @@ BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
         pDib = NULL;
     }
 
-    if (cyWinSize > ((size_t)(-1))/wDIRowBytes) {
-    {
-        MessageBox (hwnd, TEXT ("Visual PNG: image is too big");
-    }
     if (!(pDib = (BYTE *) malloc (sizeof(BITMAPINFOHEADER) +
         wDIRowBytes * cyWinSize)))
     {
@@ -851,10 +847,6 @@ BOOL FillBitmap (
             cxImgPos = (cxWinSize - cxNewSize) / 2;
         }
 
-        if (cyNewSize > ((size_t)(-1))/(cImgChannels * cxNewSize)) {
-        {
-            MessageBox (hwnd, TEXT ("Visual PNG: stretched image is too big");
-        }
         pStretchedImage = malloc (cImgChannels * cxNewSize * cyNewSize);
         pImg = pStretchedImage;
 

example.c

@@ -2,7 +2,7 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.6.24 [August 4, 2016]
+ * Last changed in libpng 1.7.0 [(PENDING RELEASE)]
  * Maintained 1998-2016 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
  * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -39,7 +39,7 @@
 #include <string.h>
 #include <stdio.h>
 #include <png.h>
-#include <zlib.h>
+#include PNG_ZLIB_HEADER /* this is the header libpng was built with */
 
 int main(int argc, const char **argv)
 {
@@ -114,13 +114,13 @@ int main(int argc, const char **argv)
 
          else
          {
-            /* Calling png_image_free is optional unless the simplified API was
+            /* 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_image_free(&image);
+               png_free_image(&image);
 
             else
                free(buffer);
@@ -983,11 +983,6 @@ void write_png(char *file_name /* , ... other image information ... */)
    png_uint_32 k, height, width;
 
    /* In this example, "image" is a one-dimensional array of bytes */
-
-   /* Guard against integer overflow */
-   if (height > PNG_SIZE_MAX/(width*bytes_per_pixel)) {
-      png_error(png_ptr, "Image_data buffer would be too large");
-   }
    png_byte image[height*width*bytes_per_pixel];
 
    png_bytep row_pointers[height];

intel/filter_sse2_intrinsics.c

@@ -1,406 +0,0 @@
-
-/* filter_sse2_intrinsics.c - SSE2 optimized filter functions
- *
- * Copyright (c) 2016-2017 Glenn Randers-Pehrson
- * Written by Mike Klein and Matt Sarett
- * Derived from arm/filter_neon_intrinsics.c
- *
- * Last changed in libpng 1.6.31 [July 27, 2017]
- *
- * 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"
-
-#ifdef PNG_READ_SUPPORTED
-
-#if PNG_INTEL_SSE_IMPLEMENTATION > 0
-
-#include <immintrin.h>
-
-/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d).
- * They're positioned like this:
- *    prev:  c b
- *    row:   a d
- * The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be
- * whichever of a, b, or c is closest to p=a+b-c.
- */
-
-static __m128i load4(const void* p) {
-   return _mm_cvtsi32_si128(*(const int*)p);
-}
-
-static void store4(void* p, __m128i v) {
-   *(int*)p = _mm_cvtsi128_si32(v);
-}
-
-static __m128i load3(const void* p) {
-   /* We'll load 2 bytes, then 1 byte,
-    * then mask them together, and finally load into SSE.
-    */
-   const png_uint_16* p01 = (png_const_uint_16p)p;
-   const png_byte*    p2  = (const png_byte*)(p01+1);
-
-   png_uint_32 v012 = (png_uint_32)(*p01)
-                    | (png_uint_32)(*p2) << 16;
-   return load4(&v012);
-}
-
-static void store3(void* p, __m128i v) {
-   /* We'll pull from SSE as a 32-bit int, then write
-    * its bottom two bytes, then its third byte.
-    */
-   png_uint_32 v012;
-   png_uint_16* p01;
-   png_byte*    p2;
-
-   store4(&v012, v);
-
-   p01 = (png_uint_16p)p;
-   p2  = (png_byte*)(p01+1);
-   *p01 = (png_uint_16)v012;
-   *p2  = (png_byte)(v012 >> 16);
-}
-
-void png_read_filter_row_sub3_sse2(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev)
-{
-   /* The Sub filter predicts each pixel as the previous pixel, a.
-    * There is no pixel to the left of the first pixel.  It's encoded directly.
-    * That works with our main loop if we just say that left pixel was zero.
-    */
-   png_size_t rb;
-
-   __m128i a, d = _mm_setzero_si128();
-
-   png_debug(1, "in png_read_filter_row_sub3_sse2");
-
-   rb = row_info->rowbytes;
-   while (rb >= 4) {
-      a = d; d = load4(row);
-      d = _mm_add_epi8(d, a);
-      store3(row, d);
-
-      row += 3;
-      rb  -= 3;
-   }
-   if (rb > 0) {
-      a = d; d = load3(row);
-      d = _mm_add_epi8(d, a);
-      store3(row, d);
-
-      row += 3;
-      rb  -= 3;
-   }
-   PNG_UNUSED(prev)
-}
-
-void png_read_filter_row_sub4_sse2(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev)
-{
-   /* The Sub filter predicts each pixel as the previous pixel, a.
-    * There is no pixel to the left of the first pixel.  It's encoded directly.
-    * That works with our main loop if we just say that left pixel was zero.
-    */
-   png_size_t rb;
-
-   __m128i a, d = _mm_setzero_si128();
-
-   png_debug(1, "in png_read_filter_row_sub4_sse2");
-
-   rb = row_info->rowbytes+4;
-   while (rb > 4) {
-      a = d; d = load4(row);
-      d = _mm_add_epi8(d, a);
-      store4(row, d);
-
-      row += 4;
-      rb  -= 4;
-   }
-   PNG_UNUSED(prev)
-}
-
-void png_read_filter_row_avg3_sse2(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev)
-{
-   /* The Avg filter predicts each pixel as the (truncated) average of a and b.
-    * There's no pixel to the left of the first pixel.  Luckily, it's
-    * predicted to be half of the pixel above it.  So again, this works
-    * perfectly with our loop if we make sure a starts at zero.
-    */
-
-   png_size_t rb;
-
-   const __m128i zero = _mm_setzero_si128();
-
-   __m128i    b;
-   __m128i a, d = zero;
-
-   png_debug(1, "in png_read_filter_row_avg3_sse2");
-   rb = row_info->rowbytes;
-   while (rb >= 4) {
-      __m128i avg;
-             b = load4(prev);
-      a = d; d = load4(row );
-
-      /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
-      avg = _mm_avg_epu8(a,b);
-      /* ...but we can fix it up by subtracting off 1 if it rounded up. */
-      avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
-                                            _mm_set1_epi8(1)));
-      d = _mm_add_epi8(d, avg);
-      store3(row, d);
-
-      prev += 3;
-      row  += 3;
-      rb   -= 3;
-   }
-   if (rb > 0) {
-      __m128i avg;
-             b = load3(prev);
-      a = d; d = load3(row );
-
-      /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
-      avg = _mm_avg_epu8(a,b);
-      /* ...but we can fix it up by subtracting off 1 if it rounded up. */
-      avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
-                                            _mm_set1_epi8(1)));
-
-      d = _mm_add_epi8(d, avg);
-      store3(row, d);
-
-      prev += 3;
-      row  += 3;
-      rb   -= 3;
-   }
-}
-
-void png_read_filter_row_avg4_sse2(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev)
-{
-   /* The Avg filter predicts each pixel as the (truncated) average of a and b.
-    * There's no pixel to the left of the first pixel.  Luckily, it's
-    * predicted to be half of the pixel above it.  So again, this works
-    * perfectly with our loop if we make sure a starts at zero.
-    */
-   png_size_t rb;
-   const __m128i zero = _mm_setzero_si128();
-   __m128i    b;
-   __m128i a, d = zero;
-
-   png_debug(1, "in png_read_filter_row_avg4_sse2");
-
-   rb = row_info->rowbytes+4;
-   while (rb > 4) {
-      __m128i avg;
-             b = load4(prev);
-      a = d; d = load4(row );
-
-      /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */
-      avg = _mm_avg_epu8(a,b);
-      /* ...but we can fix it up by subtracting off 1 if it rounded up. */
-      avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b),
-                                            _mm_set1_epi8(1)));
-
-      d = _mm_add_epi8(d, avg);
-      store4(row, d);
-
-      prev += 4;
-      row  += 4;
-      rb   -= 4;
-   }
-}
-
-/* Returns |x| for 16-bit lanes. */
-static __m128i abs_i16(__m128i x) {
-#if PNG_INTEL_SSE_IMPLEMENTATION >= 2
-   return _mm_abs_epi16(x);
-#else
-   /* Read this all as, return x<0 ? -x : x.
-   * To negate two's complement, you flip all the bits then add 1.
-    */
-   __m128i is_negative = _mm_cmplt_epi16(x, _mm_setzero_si128());
-
-   /* Flip negative lanes. */
-   x = _mm_xor_si128(x, is_negative);
-
-   /* +1 to negative lanes, else +0. */
-   x = _mm_sub_epi16(x, is_negative);
-   return x;
-#endif
-}
-
-/* Bytewise c ? t : e. */
-static __m128i if_then_else(__m128i c, __m128i t, __m128i e) {
-#if PNG_INTEL_SSE_IMPLEMENTATION >= 3
-   return _mm_blendv_epi8(e,t,c);
-#else
-   return _mm_or_si128(_mm_and_si128(c, t), _mm_andnot_si128(c, e));
-#endif
-}
-
-void png_read_filter_row_paeth3_sse2(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev)
-{
-   /* Paeth tries to predict pixel d using the pixel to the left of it, a,
-    * and two pixels from the previous row, b and c:
-    *   prev: c b
-    *   row:  a d
-    * The Paeth function predicts d to be whichever of a, b, or c is nearest to
-    * p=a+b-c.
-    *
-    * The first pixel has no left context, and so uses an Up filter, p = b.
-    * This works naturally with our main loop's p = a+b-c if we force a and c
-    * to zero.
-    * Here we zero b and d, which become c and a respectively at the start of
-    * the loop.
-    */
-   png_size_t rb;
-   const __m128i zero = _mm_setzero_si128();
-   __m128i c, b = zero,
-           a, d = zero;
-
-   png_debug(1, "in png_read_filter_row_paeth3_sse2");
-
-   rb = row_info->rowbytes;
-   while (rb >= 4) {
-      /* It's easiest to do this math (particularly, deal with pc) with 16-bit
-       * intermediates.
-       */
-      __m128i pa,pb,pc,smallest,nearest;
-      c = b; b = _mm_unpacklo_epi8(load4(prev), zero);
-      a = d; d = _mm_unpacklo_epi8(load4(row ), zero);
-
-      /* (p-a) == (a+b-c - a) == (b-c) */
-   
-      pa = _mm_sub_epi16(b,c);
-
-      /* (p-b) == (a+b-c - b) == (a-c) */
-      pb = _mm_sub_epi16(a,c);
-
-      /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
-      pc = _mm_add_epi16(pa,pb);
-
-      pa = abs_i16(pa);  /* |p-a| */
-      pb = abs_i16(pb);  /* |p-b| */
-      pc = abs_i16(pc);  /* |p-c| */
-
-      smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
-
-      /* Paeth breaks ties favoring a over b over c. */
-      nearest  = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
-                 if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
-                                                             c));
-
-      /* Note `_epi8`: we need addition to wrap modulo 255. */
-      d = _mm_add_epi8(d, nearest);
-      store3(row, _mm_packus_epi16(d,d));
-
-      prev += 3;
-      row  += 3;
-      rb   -= 3;
-   }
-   if (rb > 0) {
-      /* It's easiest to do this math (particularly, deal with pc) with 16-bit
-       * intermediates.
-       */
-      __m128i pa,pb,pc,smallest,nearest;
-      c = b; b = _mm_unpacklo_epi8(load3(prev), zero);
-      a = d; d = _mm_unpacklo_epi8(load3(row ), zero);
-
-      /* (p-a) == (a+b-c - a) == (b-c) */
-      pa = _mm_sub_epi16(b,c);
-
-      /* (p-b) == (a+b-c - b) == (a-c) */
-      pb = _mm_sub_epi16(a,c);
-
-      /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
-      pc = _mm_add_epi16(pa,pb);
-
-      pa = abs_i16(pa);  /* |p-a| */
-      pb = abs_i16(pb);  /* |p-b| */
-      pc = abs_i16(pc);  /* |p-c| */
-
-      smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
-
-      /* Paeth breaks ties favoring a over b over c. */
-      nearest  = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
-                         if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
-                                                                     c));
-
-      /* Note `_epi8`: we need addition to wrap modulo 255. */
-      d = _mm_add_epi8(d, nearest);
-      store3(row, _mm_packus_epi16(d,d));
-
-      prev += 3;
-      row  += 3;
-      rb   -= 3;
-   }
-}
-
-void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row,
-   png_const_bytep prev)
-{
-   /* Paeth tries to predict pixel d using the pixel to the left of it, a,
-    * and two pixels from the previous row, b and c:
-    *   prev: c b
-    *   row:  a d
-    * The Paeth function predicts d to be whichever of a, b, or c is nearest to
-    * p=a+b-c.
-    *
-    * The first pixel has no left context, and so uses an Up filter, p = b.
-    * This works naturally with our main loop's p = a+b-c if we force a and c
-    * to zero.
-    * Here we zero b and d, which become c and a respectively at the start of
-    * the loop.
-    */
-   png_size_t rb;
-   const __m128i zero = _mm_setzero_si128();
-   __m128i pa,pb,pc,smallest,nearest;
-   __m128i c, b = zero,
-           a, d = zero;
-
-   png_debug(1, "in png_read_filter_row_paeth4_sse2");
-
-   rb = row_info->rowbytes+4;
-   while (rb > 4) {
-      /* It's easiest to do this math (particularly, deal with pc) with 16-bit
-       * intermediates.
-       */
-      c = b; b = _mm_unpacklo_epi8(load4(prev), zero);
-      a = d; d = _mm_unpacklo_epi8(load4(row ), zero);
-
-      /* (p-a) == (a+b-c - a) == (b-c) */
-      pa = _mm_sub_epi16(b,c);
-
-      /* (p-b) == (a+b-c - b) == (a-c) */
-      pb = _mm_sub_epi16(a,c);
-
-      /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
-      pc = _mm_add_epi16(pa,pb);
-
-      pa = abs_i16(pa);  /* |p-a| */
-      pb = abs_i16(pb);  /* |p-b| */
-      pc = abs_i16(pc);  /* |p-c| */
-
-      smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));
-
-      /* Paeth breaks ties favoring a over b over c. */
-      nearest  = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
-                         if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
-                                                                     c));
-
-      /* Note `_epi8`: we need addition to wrap modulo 255. */
-      d = _mm_add_epi8(d, nearest);
-      store4(row, _mm_packus_epi16(d,d));
-
-      prev += 4;
-      row  += 4;
-      rb   -= 4;
-   }
-}
-
-#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */
-#endif /* READ */

intel/intel_init.c

@@ -1,53 +0,0 @@
-
-/* intel_init.c - SSE2 optimized filter functions
- *
- * Copyright (c) 2016-2017 Glenn Randers-Pehrson
- * Written by Mike Klein and Matt Sarett, Google, Inc.
- * Derived from arm/arm_init.c
- *
- * Last changed in libpng 1.6.29 [March 16, 2017]
- *
- * 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"
-
-#ifdef PNG_READ_SUPPORTED
-#if PNG_INTEL_SSE_IMPLEMENTATION > 0
-
-void
-png_init_filter_functions_sse2(png_structp pp, unsigned int bpp)
-{
-   /* The techniques used to implement each of these filters in SSE operate on
-    * one pixel at a time.
-    * So they generally speed up 3bpp images about 3x, 4bpp images about 4x.
-    * They can scale up to 6 and 8 bpp images and down to 2 bpp images,
-    * but they'd not likely have any benefit for 1bpp images.
-    * Most of these can be implemented using only MMX and 64-bit registers,
-    * but they end up a bit slower than using the equally-ubiquitous SSE2.
-   */
-   png_debug(1, "in png_init_filter_functions_sse2");
-   if (bpp == 3)
-   {
-      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2;
-      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2;
-      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
-         png_read_filter_row_paeth3_sse2;
-   }
-   else if (bpp == 4)
-   {
-      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2;
-      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2;
-      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
-          png_read_filter_row_paeth4_sse2;
-   }
-
-   /* No need optimize PNG_FILTER_VALUE_UP.  The compiler should
-    * autovectorize.
-    */
-}
-
-#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */
-#endif /* PNG_READ_SUPPORTED */

libpng-manual.txt

@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.32 - August 24, 2017
+ libpng version 1.7.0beta90 - August 28, 2017
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2017 Glenn Randers-Pehrson
@@ -11,15 +11,15 @@ libpng-manual.txt - A description on how to use and modify libpng
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.32 - August 24, 2017
+ libpng versions 0.97, January 1998, through 1.7.0beta90 - August 28, 2017
  Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2017 Glenn Randers-Pehrson
+ Copyright (c) 1998-2015 Glenn Randers-Pehrson
 
- libpng 1.0 beta 6 - version 0.96 - May 28, 1997
+ libpng 1.0 beta 6  version 0.96 May 28, 1997
  Updated and distributed by Andreas Dilger
  Copyright (c) 1996, 1997 Andreas Dilger
 
- libpng 1.0 beta 2 - version 0.88 - January 26, 1996
+ libpng 1.0 beta 2 - version 0.88  January 26, 1996
  For conditions of distribution and use, see copyright
  notice in png.h. Copyright (c) 1995, 1996 Guy Eric
  Schalnat, Group 42, Inc.
@@ -42,10 +42,11 @@ libpng-manual.txt - A description on how to use and modify libpng
     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
+ XIII. Changes to Libpng from version 1.6.x to 1.7.x
+  XIV. Detecting libpng
+   XV. Source code repository
+  XVI. Coding style
+ XVII. Y2K Compliance in libpng
 
 I. Introduction
 
@@ -345,23 +346,22 @@ then only check the bytes (if any) that your program didn't read.
 to replace them with custom functions.  See the discussion under
 Customizing libpng.
 
+
     FILE *fp = fopen(file_name, "rb");
     if (!fp)
     {
        return (ERROR);
     }
 
-    if (fread(header, 1, number, fp) != number)
-    {
-       return (ERROR);
-    }
-
+    fread(header, 1, number, fp);
     is_png = !png_sig_cmp(header, 0, number);
+
     if (!is_png)
     {
        return (NOT_PNG);
     }
 
+
 Next, png_struct and png_info need to be allocated and initialized.  In
 order to ensure that the size of these structures is correct even with a
 dynamically linked libpng, there are functions to initialize and
@@ -429,12 +429,16 @@ an end_info structure.
 
 If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
-errors will result in a call to PNG_ABORT() which defaults to abort().
+errors will result in a call to PNG_ABORT which defaults to abort().
 
-You can #define PNG_ABORT() to a function that does something
+You can #define PNG_ABORT to a function or other C code that does something
 more useful than abort(), as long as your function does not
 return.
 
+If you do this, you cannot #define PNG_SIMPLIFIED_READ_SUPPORTED or
+PNG_SIMPLIFIED_WRITE_SUPPORTED, because the simplified API requires
+setjmp() support.
+
 Now you need to set up the input code.  The default for libpng is to
 use the C function fread().  If you use this, you will need to pass a
 valid FILE * in the function png_init_io().  Be sure that the file is
@@ -530,15 +534,15 @@ 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 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.
+If you call the png_set_read_user_chunk_fn() function, then all unknown chunks
+will be passed to your callback when read.  You can cause known chunks to be
+passed in as well by using png_set_keep_unknown_chunks (see below) - this will
+prevent the normal libpng handling of those known chunks.
+
+If your callback returns 0 the default unknown handling will be used (see
+below).  This is new behavior in libpng 1.7, prior to 1.7 it was not possible to
+discard a chunk; PNG_HANDLE_CHUNK_IF_SAFE was forced.  Libpng 1.6.0 issues a
+warning when this was done.
 
 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
@@ -637,10 +641,8 @@ callback function:
     ...
 
     #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
-      /* ignore all unknown chunks
-       * (use global setting "2" for libpng16 and earlier):
-       */
-      png_set_keep_unknown_chunks(read_ptr, 2, NULL, 0);
+      /* ignore all unknown chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0);
 
       /* except for vpAg: */
       png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1);
@@ -654,13 +656,15 @@ User limits
 
 The PNG specification allows the width and height of an image to be as
 large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
-For safety, libpng imposes a default limit of 1 million rows and columns.
+Since very few applications really need to process such large images,
+we have imposed an arbitrary 1,000,000 limit on rows and columns.
 Larger images will be rejected immediately with a png_error() call. If
-you wish to change these limits, you can use
+you wish to change this limit, you can use
 
    png_set_user_limits(png_ptr, width_max, height_max);
 
-to set your own limits (libpng may reject some very wide images
+to set your own limits, or use width_max = height_max = 0x7fffffffL
+to allow all valid dimensions (libpng may reject some very large images
 anyway because of potential buffer overflow conditions).
 
 You should put this statement after you create the PNG structure and
@@ -675,11 +679,8 @@ If you need to retrieve the limits that are being applied, use
    height_max = png_get_user_height_max(png_ptr);
 
 The PNG specification sets no limit on the number of ancillary chunks
-allowed in a PNG datastream.  By default, libpng imposes a limit of
-a total of 1000 sPLT, tEXt, iTXt, zTXt, and unknown chunks to be stored.
-If you have set up both info_ptr and end_info_ptr, the limit applies
-separately to each.  You can change the limit on the total number of such
-chunks that will be stored, with
+allowed in a PNG datastream.  You can impose a limit on the total number
+of sPLT, tEXt, iTXt, zTXt, and unknown chunks that will be stored, with
 
    png_set_chunk_cache_max(png_ptr, user_chunk_cache_max);
 
@@ -687,10 +688,8 @@ where 0x7fffffffL means unlimited.  You can retrieve this limit with
 
    chunk_cache_max = png_get_chunk_cache_max(png_ptr);
 
-Libpng imposes a limit of 8 Megabytes (8,000,000 bytes) on the amount of
-memory that any chunk other than IDAT can occupy, originally or when
-decompressed (prior to libpng-1.6.32 the limit was only applied to compressed
-chunks after decompression). You can change this limit with
+You can also set a limit on the amount of memory that a compressed chunk
+other than IDAT can occupy, with
 
    png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max);
 
@@ -1191,20 +1190,10 @@ row_pointers prior to calling png_read_png() with
    png_set_rows(png_ptr, info_ptr, &row_pointers);
 
 Alternatively you could allocate your image in one big block and define
-row_pointers[i] to point into the proper places in your block, but first
-be sure that your platform is able to allocate such a large buffer:
-
-   /* Guard against integer overflow */
-   if (height > PNG_SIZE_MAX/(width*pixel_size)) {
-        png_error(png_ptr,"image_data buffer would be too large");
-   }
-
-   png_bytep buffer=png_malloc(png_ptr,height*width*pixel_size);
-
-   for (int i=0; i<height, i++)
-      row_pointers[i]=buffer+i*width*pixel_size;
-
-   png_set_rows(png_ptr, info_ptr, &row_pointers);
+row_pointers[i] to point into the proper places in your block.  If
+you do this, be sure to call png_read_update_info() described below,
+to update the "rowbytes" value to account for any transformations that
+change the number of bytes per row before you use it to allocate your block.
 
 If you use png_set_rows(), the application is responsible for freeing
 row_pointers (and row_pointers[i], if they were separately allocated).
@@ -1293,12 +1282,13 @@ in until png_read_end() has read the chunk data following the image.
     interlace_type, compression_type, or filter_method can
     be NULL if you are not interested in their values.
 
-    Note that png_get_IHDR() returns 32-bit data into
+    Note that png_get_IHDR() returns png_uint_32 data into
     the application's width and height variables.
     This is an unsafe situation if these are not png_uint_32
-    variables.  In such situations, the
-    png_get_image_width() and png_get_image_height()
-    functions described below are safer.
+    variables, or if they are 32-bit variables on a 64-bit
+    platform.  In such situations, the png_get_image_width()
+    and png_get_image_height() functions described below are
+    safer.
 
     width            = png_get_image_width(png_ptr,
                          info_ptr);
@@ -1331,11 +1321,6 @@ in until png_read_end() has read the chunk data following the image.
     rowbytes = png_get_rowbytes(png_ptr, info_ptr);
 
     rowbytes       - number of bytes needed to hold a row
-                     This value, the bit_depth, color_type,
-                     and the number of channels can change
-                     if you use transforms such as
-                     png_set_expand(). See
-                     png_read_update_info(), below.
 
     signature = png_get_signature(png_ptr, info_ptr);
 
@@ -1454,11 +1439,6 @@ png_set_rgb_to_gray()).
                      the single transparent color for
                      non-paletted images (PNG_INFO_tRNS)
 
-    png_get_eXIf_1(png_ptr, info_ptr, &num_exif, &exif);
-                     (PNG_INFO_eXIf)
-
-    exif           - Exif profile (array of png_byte)
-
     png_get_hIST(png_ptr, info_ptr, &hist);
                      (PNG_INFO_hIST)
 
@@ -1491,6 +1471,11 @@ png_set_rgb_to_gray()).
                            PNG_ITXT_COMPRESSION_NONE
                            PNG_ITXT_COMPRESSION_zTXt
 
+    text_ptr[i].location - location of chunk
+                           PNG_HAVE_IHDR
+                           PNG_HAVE_PLTE
+                           PNG_AFTER_IDAT
+
     text_ptr[i].key   - keyword for comment.  Must contain
                          1-79 characters.
 
@@ -1713,16 +1698,15 @@ described below.
 Data will be decoded into the supplied row buffers packed into bytes
 unless the library has been told to transform it into another format.
 For example, 4 bit/pixel paletted or grayscale data will be returned
-2 pixels/byte with the leftmost pixel in the high-order bits of the byte,
-unless png_set_packing() is called.  8-bit RGB data will be stored
+2 pixels/byte with the leftmost pixel in the high-order bits of the
+byte, unless png_set_packing() is called.  8-bit RGB data will be stored
 in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
 is called to insert filler bytes, either before or after each RGB triplet.
-
 16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
 byte of the color value first, unless png_set_scale_16() is called to
 transform it to regular RGB RGB triplets, or png_set_filler() or
-png_set_add alpha() is called to insert two filler bytes, either before
-or after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
+png_set_add alpha() is called to insert filler bytes, either before or
+after each RRGGBB triplet.  Similarly, 8-bit or 16-bit grayscale data can
 be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(),
 or png_set_scale_16().
 
@@ -1879,13 +1863,12 @@ into 4 or 8 bytes for windowing systems that need them in this format:
     if (color_type == PNG_COLOR_TYPE_RGB)
        png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
 
-where "filler" is the 8-bit or 16-bit number to fill with, and the location
-is either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
-you want the filler before the RGB or after. When filling an 8-bit pixel,
-the least significant 8 bits of the number are used, if a 16-bit number is
-supplied.  This transformation does not affect images that already have full
-alpha channels.  To add an opaque alpha channel, use filler=0xffff and
-PNG_FILLER_AFTER which will generate RGBA pixels.
+where "filler" is the 8 or 16-bit number to fill with, and the location is
+either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+you want the filler before the RGB or after.  This transformation
+does not affect images that already have full alpha channels.  To add an
+opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
+will generate RGBA pixels.
 
 Note that png_set_filler() does not change the color type.  If you want
 to do that, you can add a true alpha channel with
@@ -1895,7 +1878,7 @@ to do that, you can add a true alpha channel with
        png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
 
 where "filler" contains the alpha value to assign to each pixel.
-The png_set_add_alpha() function was added in libpng-1.2.7.
+This function was added in libpng-1.2.7.
 
 If you are reading an image with an alpha channel, and you need the
 data as ARGB instead of the normal PNG format RGBA:
@@ -2170,16 +2153,6 @@ are allocating one large chunk, you will need to build an
 array of pointers to each row, as it will be needed for some
 of the functions below.
 
-Be sure that your platform can allocate the buffer that you'll need.
-libpng internally checks for oversize width, but you'll need to
-do your own check for number_of_rows*width*pixel_size if you are using
-a multiple-row buffer:
-
-   /* Guard against integer overflow */
-   if (number_of_rows > PNG_SIZE_MAX/(width*pixel_size)) {
-        png_error(png_ptr,"image_data buffer would be too large");
-   }
-
 Remember: Before you call png_read_update_info(), the png_get_*()
 functions return the values corresponding to the original PNG image.
 After you call png_read_update_info the values refer to the image
@@ -2268,8 +2241,7 @@ is exactly the same.  If you are planning on displaying the image
 after each pass, the "rectangle" effect is generally considered the
 better looking one.
 
-If you only want the "sparkle" effect, just call png_read_row() or
-png_read_rows() as
+If you only want the "sparkle" effect, just call png_read_rows() as
 normal, with the third parameter NULL.  Make sure you make pass over
 the image number_of_passes times, and you don't change the data in the
 rows between calls.  You can change the locations of the data, just
@@ -2278,8 +2250,6 @@ pass, and assumes the data from previous passes is still valid.
 
     png_read_rows(png_ptr, row_pointers, NULL,
         number_of_rows);
-    or
-    png_read_row(png_ptr, row_pointers, NULL);
 
 If you only want the first effect (the rectangles), do the same as
 before except pass the row buffer in the third parameter, and leave
@@ -2287,8 +2257,6 @@ the second parameter NULL.
 
     png_read_rows(png_ptr, NULL, row_pointers,
         number_of_rows);
-    or
-    png_read_row(png_ptr, NULL, row_pointers);
 
 If you don't want libpng to handle the interlacing details, just call
 png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images.
@@ -2504,7 +2472,6 @@ your application instead of by libpng, you can use
              PNG_INFO_gAMA, PNG_INFO_sBIT,
              PNG_INFO_cHRM, PNG_INFO_PLTE,
              PNG_INFO_tRNS, PNG_INFO_bKGD,
-             PNG_INFO_eXIf,
              PNG_INFO_hIST, PNG_INFO_pHYs,
              PNG_INFO_oFFs, PNG_INFO_tIME,
              PNG_INFO_pCAL, PNG_INFO_sRGB,
@@ -2789,11 +2756,10 @@ section below for more information on the libpng error handling.
 
 If you would rather avoid the complexity of setjmp/longjmp issues,
 you can compile libpng with PNG_NO_SETJMP, in which case
-errors will result in a call to PNG_ABORT() which defaults to abort().
+errors will result in a call to PNG_ABORT which defaults to abort().
 
-You can #define PNG_ABORT() to a function that does something
-more useful than abort(), as long as your function does not
-return.
+You can #define PNG_ABORT to a function or other C code 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
@@ -2886,7 +2852,7 @@ filter types.
        PNG_FILTER_UP    | PNG_FILTER_VALUE_UP   |
        PNG_FILTER_AVG   | PNG_FILTER_VALUE_AVG  |
        PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH|
-       PNG_ALL_FILTERS  | PNG_FAST_FILTERS);
+       PNG_ALL_FILTERS);
 
 If an application wants to start and stop using particular filters during
 compression, it should start out with all of the filters (to ensure that
@@ -3004,7 +2970,6 @@ width, height, bit_depth, and color_type must be the same in each call.
                      (array of png_color)
     num_palette    - number of entries in the palette
 
-
     png_set_gAMA(png_ptr, info_ptr, file_gamma);
     png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma);
 
@@ -3104,11 +3069,6 @@ width, height, bit_depth, and color_type must be the same in each call.
                      single transparent color for
                      non-paletted images (PNG_INFO_tRNS)
 
-    png_set_eXIf_1(png_ptr, info_ptr, num_exif, exif);
-
-    exif           - Exif profile (array of
-                     png_byte) (PNG_INFO_eXIf)
-
     png_set_hIST(png_ptr, info_ptr, hist);
 
     hist           - histogram of palette (array of
@@ -3134,6 +3094,10 @@ width, height, bit_depth, and color_type must be the same in each call.
                            PNG_TEXT_COMPRESSION_zTXt
                            PNG_ITXT_COMPRESSION_NONE
                            PNG_ITXT_COMPRESSION_zTXt
+    text_ptr[i].location - location of chunk
+                           PNG_HAVE_IHDR
+                           PNG_HAVE_PLTE
+                           PNG_AFTER_IDAT
     text_ptr[i].key   - keyword for comment.  Must contain
                  1-79 characters.
     text_ptr[i].text  - text comments for current
@@ -3317,7 +3281,7 @@ 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_buffer(buffer, png_timep) is provided to
+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.
 
@@ -3774,26 +3738,21 @@ 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, set the
-     version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
-     (this is REQUIRED, your program may crash if you don't do it.)
+  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 sample format.
+  3) Set the png_image 'format' member to the required
+     format and allocate a buffer for the image.
 
-  4) Allocate a buffer for the image and, if required, the color-map.
-
-  5) Call png_image_finish_read to read the image and, if required, the
-     color-map into your buffers.
+  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.  The only caveat is that if you
-request a color-mapped image from a PNG that is full-color or makes
-complex use of an alpha channel the transformation is extremely lossy and the
-result may look terrible.
+during the png_image_finish_read() step.
 
 To write a PNG file using the simplified API:
 
@@ -3802,14 +3761,13 @@ To write a PNG file using the simplified API:
 
   2) Initialize the members of the structure that describe the
      image, setting the 'format' member to the format of the
-     image samples.
+     image in memory.
 
   3) Call the appropriate png_image_write... function with a
-     pointer to the image and, if necessary, the color-map to write
-     the PNG data.
+     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 defines the in-memory format of an image that you
+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_controlp opaque  Initialize to NULL, free with png_image_free
@@ -3822,15 +3780,15 @@ need to write.  The "png_image" structure contains the following members:
    png_uint_32  warning_or_error;
    char         message[64];
 
-In the event of an error or warning the "warning_or_error"
+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 the "warning_or_error" 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:
+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
@@ -3862,72 +3820,64 @@ 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 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 https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
-approximation used elsewhere in libpng.
-
 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.
 
-The samples are either contained directly in the image data, between 1 and 8
-bytes per pixel according to the encoding, or are held in a color-map indexed
-by bytes in the image data.  In the case of a color-map the color-map entries
-are individual samples, encoded as above, and the image data has one byte per
-pixel to select the relevant sample from the color-map.
+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 component encodings.
+separate defines for each of the two channel encodings.
 
-A format is built up using single bit flag values.  All combinations are
-valid.  Formats can be built up from the flag values or you can use one of
-the predefined values below.  When testing formats always use the FORMAT_FLAG
-macros to test for individual features - future versions of the library may
-add new flags.
+A format is built up using one-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
+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 the
-appropriate "_SUPPORTED" macro, one of:
+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    format with an alpha channel
-   PNG_FORMAT_FLAG_COLOR    color format: otherwise grayscale
-   PNG_FORMAT_FLAG_LINEAR   2-byte channels else 1-byte
-   PNG_FORMAT_FLAG_COLORMAP image data is color-mapped
-   PNG_FORMAT_FLAG_BGR      BGR colors, else order is RGB
-   PNG_FORMAT_FLAG_AFIRST   alpha channel comes first
+   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 (sRGB) formats:
+First the single byte formats:
 
-   PNG_FORMAT_GRAY
-   PNG_FORMAT_GA
-   PNG_FORMAT_AG
-   PNG_FORMAT_RGB
-   PNG_FORMAT_BGR
-   PNG_FORMAT_RGBA
-   PNG_FORMAT_ARGB
-   PNG_FORMAT_BGRA
-   PNG_FORMAT_ABGR
+   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
@@ -3936,22 +3886,22 @@ components in the linear format.  The components are 16-bit integers in
 the native byte order for your platform, and there is no provision for
 swapping the bytes to a different endian condition.
 
-   PNG_FORMAT_LINEAR_Y
+   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)
 
-With color-mapped formats the image data is one byte for each pixel. The byte
-is an index into the color-map which is formatted as above.  To obtain a
-color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
-to one of the above definitions, or you can use one of the definitions below.
+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_RGB_COLORMAP
-   PNG_FORMAT_BGR_COLORMAP
-   PNG_FORMAT_RGBA_COLORMAP
-   PNG_FORMAT_ARGB_COLORMAP
-   PNG_FORMAT_BGRA_COLORMAP
-   PNG_FORMAT_ABGR_COLORMAP
+   PNG_FORMAT_OF_COLORMAP(fmt) ((fmt) & ~PNG_FORMAT_FLAG_COLORMAP)
 
 PNG_IMAGE macros
 
@@ -3959,9 +3909,9 @@ 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 for color-mapped formats.  The
-remaining macros return information about the rows in the image and the
-complete image.
+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
@@ -3969,39 +3919,46 @@ 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: 1 or 2.
+    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_MAXIMUM_COLORMAP_COMPONENTS(fmt)
-    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.
-
   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
+   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.
@@ -4027,54 +3984,19 @@ Information about the whole row, or whole image
    to start the next row on a 4-byte boundary.
 
   PNG_IMAGE_BUFFER_SIZE(image, row_stride)
-   Return 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_SIZE(image)
-   Return the size, in bytes, of the image in memory given just a png_image;
-   the row stride is the minimum stride required for the image.
-
-  PNG_IMAGE_COLORMAP_SIZE(image)
-   Return the size, in bytes, of the color-map of this image.  If the image
-   format is not a color-map format this will return a size sufficient for
-   256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
-   you don't want to allocate a color-map in this case.
-
-PNG_IMAGE_FLAG_*
-
-Flags containing additional information about the image are held in
-the 'flags' field of png_image.
+    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.  This
+    macro takes care of multiplying row_stride by PNG_IMAGE_PIXEL_COMONENT_SIZE
+    when the image has 2-byte components.
 
   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_FAST == 0x02
-   On write emphasise speed over compression; the resultant PNG file will be
-   larger but will be produced significantly faster, particular for large
-   images.  Do not use this option for images which will be distributed, only
-   used it when producing intermediate files that will be read back in
-   repeatedly.  For a typical 24-bit image the option will double the read
-   speed at the cost of increasing the image size by 25%, however for many
-   more compressible images the PNG file can be 10 times larger with only a
-   slight speed gain.
-
-  PNG_IMAGE_FLAG_16BIT_sRGB == 0x04
-    On read if the image is a 16-bit per component image and there is no gAMA
-    or sRGB chunk assume that the components are sRGB encoded.  Notice that
-    images output by the simplified API always have gamma information; setting
-    this flag only affects the interpretation of 16-bit images from an
-    external source.  It is recommended that the application expose this flag
-    to the user; the user can normally easily recognize the difference between
-    linear and sRGB encoding.  This flag has no effect on write - the data
-    passed to the write APIs must have the correct encoding (as defined
-    above.)
-
-    If the flag is not set (the default) input 16-bit per component data is
-    assumed to be linear.
-
-    NOTE: the flag can only be set after the png_image_begin_read_ call,
-    because that call initializes the 'flags' field.
+  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
 
@@ -4172,11 +4094,10 @@ 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.  If you pass zero, libpng will
-calculate the row_stride for you from the width and number of channels.
+indicates a bottom-up row layout in the buffer.
 
 Note that the write API does not support interlacing, sub-8-bit pixels,
-indexed (paletted) images, or most ancillary chunks.
+and indexed (paletted) images.
 
 VI. Modifying/Customizing libpng
 
@@ -4267,7 +4188,7 @@ Error handling in libpng is done through png_error() and png_warning().
 Errors handled through png_error() are fatal, meaning that png_error()
 should never return to its caller.  Currently, this is handled via
 setjmp() and longjmp() (unless you have compiled libpng with
-PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
+PNG_NO_SETJMP, in which case it is handled via PNG_ABORT),
 but you could change this to do things like exit() if you should wish,
 as long as your function does not return.
 
@@ -4286,6 +4207,8 @@ functions after png_create_*_struct() has been called by calling:
         png_voidp error_ptr, png_error_ptr error_fn,
         png_error_ptr warning_fn);
 
+    png_voidp error_ptr = png_get_error_ptr(png_ptr);
+
 If NULL is supplied for either error_fn or warning_fn, then the libpng
 default function will be used, calling fprintf() and/or longjmp() if a
 problem is encountered.  The replacement error functions should have
@@ -4297,11 +4220,6 @@ parameters as follows:
     void user_warning_fn(png_structp png_ptr,
         png_const_charp warning_msg);
 
-Then, within your user_error_fn or user_warning_fn, you can retrieve
-the error_ptr if you need it, by calling
-
-    png_voidp error_ptr = png_get_error_ptr(png_ptr);
-
 The motivation behind using setjmp() and longjmp() is the C++ throw and
 catch exception handling methods.  This makes the code much easier to write,
 as there is no need to check every return code of every function call.
@@ -4439,9 +4357,8 @@ for any images with bit depths less than 8 bits/pixel.
 The 'method' parameter sets the main filtering method, which is
 currently only '0' in the PNG 1.2 specification.  The 'filters'
 parameter sets which filter(s), if any, should be used for each
-scanline.  Possible values are PNG_ALL_FILTERS, PNG_NO_FILTERS,
-or PNG_FAST_FILTERS to turn filtering on and off, or to turn on
-just the fast-decoding subset of filters, respectively.
+scanline.  Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS
+to turn filtering on and off, respectively.
 
 Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB,
 PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise
@@ -4455,19 +4372,12 @@ means the first row must always be adaptively filtered, because libpng
 currently does not allocate the filter buffers until png_write_row()
 is called for the first time.)
 
-    filters = PNG_NO_FILTERS;
-    filters = PNG_ALL_FILTERS;
-    filters = PNG_FAST_FILTERS;
-
-    or
-
-    filters = PNG_FILTER_NONE | PNG_FILTER_SUB |
+    filters = PNG_FILTER_NONE | PNG_FILTER_SUB
               PNG_FILTER_UP | PNG_FILTER_AVG |
-              PNG_FILTER_PAETH;
+              PNG_FILTER_PAETH | PNG_ALL_FILTERS;
 
     png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
        filters);
-
               The second parameter can also be
               PNG_INTRAPIXEL_DIFFERENCING if you are
               writing a PNG to be embedded in a MNG
@@ -4960,18 +4870,22 @@ PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said
 that it could be used to override them.  Now this function will reduce or
 increase the limits.
 
-Starting in libpng-1.5.22, default user limits were established. These
-can be overridden by application calls to png_set_user_limits(),
-png_set_user_chunk_cache_max(), and/or png_set_user_malloc_max().
-The limits are now
-                             max possible  default
+Starting in libpng-1.5.10, the user limits can be set en masse with the
+configuration option PNG_SAFE_LIMITS_SUPPORTED.  If this option is enabled,
+a set of "safe" limits is applied in pngpriv.h.  These can be overridden by
+application calls to png_set_user_limits(), png_set_user_chunk_cache_max(),
+and/or png_set_user_malloc_max() that increase or decrease the limits.  Also,
+in libpng-1.5.10 the default width and height limits were increased
+from 1,000,000 to 0x7fffffff (i.e., made unlimited).  Therefore, the
+limits are now
+                               default      safe
    png_user_width_max        0x7fffffff    1,000,000
    png_user_height_max       0x7fffffff    1,000,000
-   png_user_chunk_cache_max  0 (unlimited) 1000
+   png_user_chunk_cache_max  0 (unlimited)   128
    png_user_chunk_malloc_max 0 (unlimited) 8,000,000
 
 The png_set_option() function (and the "options" member of the png struct) was
-added to libpng-1.5.15, with option PNG_ARM_NEON.
+added to libpng-1.5.15.
 
 The library now supports a complete fixed point implementation and can
 thus be used on systems that have no floating point support or very
@@ -5143,10 +5057,6 @@ enforced.  The sRGB chunk is allowed to appear in images with any color type
 and is interpreted by libpng to convey a one-tracer-curve gray profile or a
 three-tracer-curve RGB profile as appropriate.
 
-Libpng 1.5.x 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 back to /MDd for libpng 1.6.x.
-
 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.
@@ -5212,17 +5122,58 @@ It can be set for testing debug or beta builds to ensure that they will compile
 when the build type is switched to RC or STABLE. In essence this overrides the
 PNG_LIBPNG_BUILD_BASE_TYPE definition which is not directly user controllable.
 
-Starting with libpng-1.6.19, attempting to set an over-length PLTE chunk
-is an error. Previously this requirement of the PNG specification was not
-enforced, and the palette was always limited to 256 entries. An over-length
-PLTE chunk found in an input PNG is silently truncated.
+XIII.  Changes to Libpng from version 1.6.x to 1.7.x
 
-Starting with libpng-1.6.31, the eXIf chunk is supported. Libpng does not
-attempt to decode the Exif profile; it simply returns a byte array
-containing the profile to the calling application which must do its own
-decoding.
+Some functions that were deprecated in libpng-1.6.0 were removed:
+    png_reset_zstream(),
+    png_info_init_3(),
+    png_data_freer() and its associated flags,
+    png_malloc_default(),
+    and png_free_default().
 
-XIII.  Detecting libpng
+These apparently unused experimental functions have been deprecated
+and the code within them, except for the APIs, has been removed.
+    png_set_filter_heuristics()
+    and png_set_filter_heuristics_fixed()
+
+A location byte was added to the png_text structure.
+
+A new private header file, "pngchunk.h", was added.
+
+The PNG_ABORT() macro was changed to PNG_ABORT, and the default is now
+"abort()" for all platforms (previously it was "ExitProcess(0)" on
+Windows platforms).  Starting with libpng-1.7.0 you have to define
+PNG_ABORT instead of PNG_ABORT(), and you must include a terminating
+semicolon in your definition, e.g.,
+
+    #if PNGCRUSH_LIBPNG_VER >= 10700
+    #  ifdef _WINDOWS_
+    #    define PNG_ABORT ExitProcess(0);
+    #  else
+    #    define PNG_ABORT abort();
+    #  endif
+    #else
+    #  ifdef _WINDOWS_
+    #    define PNG_ABORT() ExitProcess(0)
+    #  else
+    #    define PNG_ABORT() abort()
+    #  endif
+    #endif
+
+The png_get_IHDR() function now allows users to supply NULL for any
+argument in which they aren't interested.  Previously, the width, height,
+bit_depth, and color_type arguments were not allowed to be NULL.
+
+The 8-bit compose and rgb_to_grayscale operations were made more accurate.
+While these did not introduce API incompatibility, there may be differences
+in unit test results.
+
+Internal "affirm()" and "impossible()" macros were added, along with
+some internal supporting macros and functions. These are similar to the
+ANSI-C "assert()" macro but they are not affected by NDEBUG, and they are
+private (not visible to nor usable by libpng applications).
+
+XIV.  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
@@ -5261,7 +5212,7 @@ simple verbal discriptions of bug fixes, reported either to the
 SourceForge bug tracker, to the png-mng-implement at lists.sf.net
 mailing list, as github issues, or directly to glennrp.
 
-XV. Coding style
+XVI. Coding style
 
 Our coding style is similar to the "Allman" style
 (See https://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
@@ -5306,6 +5257,19 @@ the statement that follows the comment:
      */
     statement;
 
+%17+%Linus Torvalds recomends putting the leading "/*" in multiple-line
+%17+%comments on a separate line:
+%17+%
+%17+%    /*
+%17+%     * This is a multiple-line
+%17+%     * comment.
+%17+%     */
+%17+%    statement;
+%17+%
+%17+%See
+%17+%https://developers.slashdot.org/story/16/07/12/2036201
+%17+%/linus-torvalds-in-sweary-rant-about-punctuation-in-kernel-comments
+%17+%
 Very short comments can be placed after the end of the statement
 to which they pertain:
 
@@ -5381,12 +5345,10 @@ We prefer #ifdef and #ifndef to #if defined() and #if !defined()
 when there is only one macro being tested.  We always use parentheses
 with "defined".
 
-We express integer constants that are used as bit masks in hex format,
-with an even number of lower-case hex digits, and to make them unsigned
-(e.g., 0x00U, 0xffU, 0x0100U) and long if they are greater than 0x7fff
-(e.g., 0xffffUL).
+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 rather than camelCase in names, except
+We prefer to use underscores in variable names rather than camelCase, except
 for a few type names that we inherit from zlib.h.
 
 We prefer "if (something != 0)" and "if (something == 0)" over
@@ -5399,13 +5361,13 @@ Lines do not exceed 80 characters.
 
 Other rules can be inferred by inspecting the libpng source.
 
-XVI. Y2K Compliance in libpng
+XVII. Y2K Compliance in libpng
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.32 are Y2K compliant.  It is my belief that earlier
+upward through 1.7.0beta90 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
@@ -5421,9 +5383,8 @@ in libpng-1.6.x and will be removed from libpng-1.7.0.
 
 There are seven time-related functions:
 
-    png_convert_to_rfc_1123_buffer() in png.c
-      (formerly png_convert_to_rfc_1152() in error, and
-      also formerly png_convert_to_rfc_1123())
+    png_convert_to_rfc_1123() in png.c
+      (formerly png_convert_to_rfc_1152() in error)
     png_convert_from_struct_tm() in pngwrite.c, called
       in pngwrite.c
     png_convert_from_time_t() in pngwrite.c

libpng.pc.in

@@ -6,7 +6,6 @@ includedir=@includedir@/libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 Name: libpng
 Description: Loads and saves PNG files
 Version: @PNGLIB_VERSION@
-Requires: zlib
 Libs: -L${libdir} -lpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 Libs.private: @LIBS@
 Cflags: -I${includedir}