[libpng16] Imported from libpng-1.6.18rc03.tar

to png.h to avoid compatibility warnings.

ANNOUNCE

@@ -1,5 +1,4 @@
-
-Libpng 1.6.0beta04 - December 30, 2011
+Libpng 1.6.18rc03 - July 13, 2015
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -9,100 +8,109 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.6.0beta04.tar.xz (LZMA-compressed, recommended)
-   1.6.0beta04.tar.gz
-   1.6.0beta04.tar.bz2
+   1.6.18rc03.tar.xz (LZMA-compressed, recommended)
+   1.6.18rc03.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp160b04.7z  (LZMA-compressed, recommended)
-   lp160b04.zip
+   lp1618r03.7z  (LZMA-compressed, recommended)
+   lp1618r03.zip
 
 Other information:
 
-   1.6.0beta04-README.txt
-   1.6.0beta04-LICENSE.txt
+   1.6.18rc03-README.txt
+   1.6.18rc03-LICENSE.txt
+   libpng-1.6.18rc03-*.asc (armored detached GPG signatures)
 
-Changes since the last public release (1.5.7):
+Changes since the last public release (1.6.17):
 
-Version 1.6.0beta01 [December 15, 2011]
-  Removed machine-generated configure files from the GIT repository (they will
-    continue to appear in the tarball distributions).
-  Restored the new 'simplified' API, which was started in libpng-1.5.7beta02
-    but later deleted from libpng-1.5.7beta05.
-  Added example programs for the new 'simplified' API.
-  Added ANSI-C (C90) headers and require them, and take advantage of the
-    change. Also fixed some of the projects/* and contrib/* files that needed
-    updates for libpng16 and the move of pngvalid.c.
-    With this change the required ANSI-C header files are assumed to exist: the
-    implementation must provide float.h, limits.h, stdarg.h and stddef.h and
-    libpng relies on limits.h and stddef.h existing and behaving as defined
-    (the other two required headers aren't used).  Non-ANSI systems that don't
-    have stddef.h or limits.h will have to provide an appropriate fake
-    containing the relevant types and #defines.
-  The use of FAR/far has been eliminated and the definition of png_alloc_size_t
-    is now controlled by a flag so that 'small size_t' systems can select it
-    if necessary.  Libpng 1.6 may not currently work on such systems -- it
-    seems likely that it will ask 'malloc' for more than 65535 bytes with any
-    image that has a sufficiently large row size (rather than simply failing
-    to read such images).
-  New tools directory containing tools used to generate libpng code.
-  Fixed race conditions in parallel make builds. With higher degrees of
-    parallelism during 'make' the use of the same temporary file names such
-    as 'dfn*' can result in a race where a temporary file from one arm of the
-    build is deleted or overwritten in another arm.  This changes the
-    temporary files for suffix rules to always use $* and ensures that the
-    non-suffix rules use unique file names.
+Version 1.6.18beta01 [April 1, 2015]
+  Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros.  They
+    have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+    bug report by Andrew Church).
+  Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c.  This
+    fixes some arithmetic errors that caused some tests to fail on
+    some 32-bit platforms (Bug reports by Peter Breitenlohner [i686]
+    and Petr Gajdos [i586]).
 
-Version 1.6.0beta02 [December 21, 2011]
-  Correct configure builds where build and source directories are separate.
-    The include path of 'config.h' was erroneously made relative in pngvalid.c
-    in libpng 1.5.7.
+Version 1.6.18beta02 [April 26, 2015]
+  Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
+    (Bug report by Viktor Szaka'ts).
 
-Version 1.6.0beta03 [December 22, 2011]
-  Start-up code size improvements, error handler flexibility. These changes
-    alter how the tricky allocation of the initial png_struct and png_info
-    structures are handled. png_info is now handled in pretty much the same
-    way as everything else, except that the allocations handle NULL return
-    silently.  png_struct is changed in a similar way on allocation and on
-    deallocation a 'safety' error handler is put in place (which should never
-    be required).  The error handler itself is changed to permit mismatches
-    in the application and libpng error buffer size; however, this means a
-    silent change to the API to return the jmp_buf if the size doesn't match
-    the size from the libpng compilation; libpng now allocates the memory and
-    this may fail.  Overall these changes result in slight code size
-    reductions; however, this is a reduction in code that is always executed
-    so is particularly valuable.  Overall on a 64-bit system the libpng DLL
-    decreases in code size by 1733 bytes.  pngerror.o increases in size by
-    about 465 bytes because of the new functionality.
+Version 1.6.18beta03 [May 6, 2015]
+  Replaced "unexpected" with an integer (0xabadca11) in pngset.c
+    where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.
+  Added contrib/examples/simpleover.c, to demonstrate how to handle
+    alpha compositing of multiple images, using the "simplified API"
+    and an example PNG generation tool, contrib/examples/genpng.c
+    (John Bowler).
 
-Version 1.6.0beta04 [December 30, 2011]
-  Regenerated configure scripts with automake-1.11.2
-  Eliminated png_info_destroy(). It is now used only in png.c and only calls
-    one other internal function and memset().
-  Enabled png_get_sCAL_fixed() if floating point APIs are enabled. Previously
-    it was disabled whenever internal fixed point arithmetic was selected,
-    which meant it didn't exist even on systems where FP was available but not
-    preferred.
-  Added pngvalid.c compile time checks for const APIs.
-  Implemented 'restrict' for png_info and png_struct. Because of the way
-    libpng works both png_info and png_struct are always accessed via a
-    single pointer.  This means adding C99 'restrict' to the pointer gives
-    the compiler some opportunity to optimize the code.  This change allows
-    that.
-  Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper
-    location in configure.ac (Gilles Espinasse).
-  Changed png_memcpy to C assignment where appropriate. Changed all those
-    uses of png_memcpy that were doing a simple assignment to assignments
-    (all those cases where the thing being copied is a non-array C L-value).
-  Added some error checking to png_set_*() routines.
-  Removed the reference to the non-exported function png_memcpy() from
-    example.c.
-  Fixed the Visual C 64-bit build - it requires jmp_buf to be aligned, but
-    it had become misaligned.
-  Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32
-    and unsigned long are of different sizes.
+Version 1.6.18beta04 [May 20, 2015]
+  PNG_RELEASE_BUILD replaces tests where the code depended on the build base
+    type and can be defined on the command line, allowing testing in beta
+    builds (John Bowler).
+  Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c
+  Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
+    report from Christopher Ferris).
+
+Version 1.6.18beta05 [May 31, 2015]
+  Backport filter selection code from libpng-1.7.0beta51, to combine
+    sub_row, up_row, avg_row, and paeth_row into try_row and tst_row.
+  Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c
+    to avoid confusion with the libpng private macros.
+  Fixed old cut&paste bug in the weighted filter selection code in
+    pngwutil.c, introduced in libpng-0.95, March 1997.
+
+Version 1.6.18beta06 [June 1, 2015]
+  Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the
+    compiled library size. It never worked properly and as far as we can
+    tell, no one uses it. The png_set_filter_heuristics() and
+    png_set_filter_heuristics_fixed() APIs are retained but deprecated
+    and do nothing.
+
+Version 1.6.18beta07 [June 6, 2015]
+  Removed non-working progressive reader 'skip' function. This
+    function has apparently never been used. It was implemented
+    to support back-door modification of png_struct in libpng-1.4.x
+    but (because it does nothing and cannot do anything) was apparently
+    never tested (John Bowler).
+  Fixed cexcept.h in which GCC 5 now reports that one of the auto
+    variables in the Try macro needs to be volatile to prevent value
+    being lost over the setjmp (John Bowler).
+  Fixed NO_WRITE_FILTER and -Wconversion build breaks (John Bowler).
+  Fix g++ build breaks (John Bowler).
+  Quieted some Coverity issues in pngfix.c, png-fix-itxt.c, pngvalid.c,
+    pngstest.c, and pngimage.c. Most seem harmless, but png-fix-itxt
+    would only work with iTXt chunks with length 255 or less.
+  Added #ifdef's to contrib/examples programs so people don't try
+    to compile them without the minimum required support enabled
+    (suggested by Flavio Medeiros).
+
+Version 1.6.18beta08 [June 30, 2015]
+  Eliminated the final two Coverity defects (insecure temporary file
+    handling in contrib/libtests/pngstest.c; possible overflow of
+    unsigned char in contrib/tools/png-fix-itxt.c). To use the "secure"
+    file handling, define PNG_USE_MKSTEMP, otherwise "tmpfile()" will
+    be used.
+  Removed some unused WEIGHTED_FILTER macros from png.h and pngstruct.h
+
+Version 1.6.18beta09 [July 5, 2015]
+  Removed some useless typecasts from contrib/tools/png-fix-itxt.c
+  Fixed a new signed-unsigned comparison in pngrtran.c (Max Stepin).
+  Replaced arbitrary use of 'extern' with #define PNG_LINKAGE_*.  To
+    preserve API compatibility, the new defines all default to "extern"
+    (requested by Jan Nijtmans).
+
+Version 1.6.18rc01 [July 9, 2015]
+  Belatedly added Mans Rullgard and James Yu to the list of Contributing
+    Authors.
+
+Version 1.6.18rc02 [July 12, 2015]
+  Restored unused FILTER_HEURISTIC macros removed at libpng-1.6.18beta08
+    to png.h to avoid compatibility warnings.
+
+Version 1.6.18rc03 [July 13, 2015]
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
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CMakeLists.txt

@@ -1,6 +1,6 @@
 # CMakeLists.txt
 
-# Copyright (C) 2007-2011 Glenn Randers-Pehrson
+# Copyright (C) 2007-2015 Glenn Randers-Pehrson
 
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -9,33 +9,14 @@
 cmake_minimum_required(VERSION 2.4.4)
 set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true)
 
-if(UNIX AND NOT DEFINED CMAKE_BUILD_TYPE)
-  if(CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION EQUAL 4)
-    # workaround CMake 2.4.x bug
-    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
-        "Choose the type of build, options are:
-           None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used)
-           Debug
-           Release
-           RelWithDebInfo
-           MinSizeRel.")
-  else()
-    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING
-        "Choose the type of build, options are:
-           None(CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used)
-           Debug
-           Release
-           RelWithDebInfo
-           MinSizeRel.")
-  endif()
-endif()
+set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
 
 project(libpng C)
 enable_testing()
 
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 0)
+set(PNGLIB_RELEASE 18)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
@@ -49,8 +30,7 @@ if(NOT WIN32)
     PATHS /usr/lib /usr/local/lib
   )
   if(NOT M_LIBRARY)
-    message(STATUS
-      "math library 'libm' not found - floating point support disabled")
+    message(STATUS "math lib 'libm' not found; floating point support disabled")
   endif()
 else()
   # not needed on windows
@@ -58,22 +38,14 @@ else()
 endif()
 
 # COMMAND LINE OPTIONS
-if(DEFINED PNG_SHARED)
-  option(PNG_SHARED "Build shared lib" ${PNG_SHARED})
-else()
-  option(PNG_SHARED "Build shared lib" ON)
-endif()
-if(DEFINED PNG_STATIC)
-  option(PNG_STATIC "Build static lib" ${PNG_STATIC})
-else()
-  option(PNG_STATIC "Build static lib" ON)
-endif()
-
-option(PNG_TESTS  "Build libpng tests" YES)
+option(PNG_SHARED "Build shared lib" ON)
+option(PNG_STATIC "Build static lib" ON)
+option(PNG_TESTS  "Build libpng tests" ON)
 
 # Many more configuration options could be added here
-option(PNG_DEBUG         "Build with debug output" NO)
-option(PNGARG            "Disable ANSI-C prototypes" NO)
+option(PNG_FRAMEWORK "Build OS X framework" OFF)
+option(PNG_DEBUG     "Build with debug output" OFF)
+option(PNGARG        "Disable ANSI-C prototypes" OFF)
 
 # SET LIBNAME
 set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
@@ -139,8 +111,11 @@ endif()
 # NOW BUILD OUR TARGET
 include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR})
 
+unset(PNG_LIB_TARGETS)
+
 if(PNG_SHARED)
   add_library(${PNG_LIB_NAME} SHARED ${libpng_sources})
+  set(PNG_LIB_TARGETS ${PNG_LIB_NAME})
   if(MSVC)
     # msvc does not append 'lib' - do it here to have consistent name
     set_target_properties(${PNG_LIB_NAME} PROPERTIES PREFIX "lib")
@@ -150,9 +125,10 @@ if(PNG_SHARED)
 endif()
 
 if(PNG_STATIC)
-# does not work without changing name
+  # does not work without changing name
   set(PNG_LIB_NAME_STATIC ${PNG_LIB_NAME}_static)
   add_library(${PNG_LIB_NAME_STATIC} STATIC ${libpng_sources})
+  list(APPEND PNG_LIB_TARGETS ${PNG_LIB_NAME_STATIC})
   if(MSVC)
     # msvc does not append 'lib' - do it here to have consistent name
     set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES PREFIX "lib")
@@ -160,6 +136,29 @@ if(PNG_STATIC)
   target_link_libraries(${PNG_LIB_NAME_STATIC} ${ZLIB_LIBRARY} ${M_LIBRARY})
 endif()
 
+if(PNG_FRAMEWORK)
+  set(PNG_LIB_NAME_FRAMEWORK ${PNG_LIB_NAME}_framework)
+  add_library(${PNG_LIB_NAME_FRAMEWORK} SHARED ${libpng_sources})
+  list(APPEND PNG_LIB_TARGETS ${PNG_LIB_NAME_FRAMEWORK})
+  set_target_properties(${PNG_LIB_NAME_FRAMEWORK} PROPERTIES
+    FRAMEWORK TRUE
+    FRAMEWORK_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_SHORT_VERSION_STRING ${PNGLIB_MAJOR}.${PNGLIB_MINOR}
+    MACOSX_FRAMEWORK_BUNDLE_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_IDENTIFIER org.libpng.libpng
+    XCODE_ATTRIBUTE_INSTALL_PATH "@rpath"
+    PUBLIC_HEADER "${libpng_public_hdrs}"
+    OUTPUT_NAME png)
+  target_link_libraries(${PNG_LIB_NAME_FRAMEWORK} ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
+if(NOT PNG_LIB_TARGETS)
+  message(SEND_ERROR
+    "No library variant selected to build. "
+    "Please enable at least one of the following options: "
+    " PNG_STATIC, PNG_SHARED, PNG_FRAMEWORK")
+endif()
+
 if(PNG_SHARED AND WIN32)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL)
 endif()
@@ -191,16 +190,18 @@ if(PNG_TESTS AND PNG_SHARED)
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn4a16.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn6a08.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn6a16.png
-    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn1g04.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g01.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g02.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g04.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn2c16.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn3p08.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbgn2c16.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbgn3p08.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbrn2c08.png
-    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbwn1g16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbwn0g16.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbwn3p08.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbyn3p08.png
-    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n1g08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n0g08.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n2c08.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n3p08.png
     ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp1n3p08.png
@@ -209,11 +210,7 @@ endif()
 
 # Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set
 IF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
-  IF(WIN32)
-    SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "bin")
-  ELSE(WIN32)
-    SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
-  ENDIF(WIN32)
+  SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
 ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
 
 # Set a variable with CMake code which:
@@ -221,18 +218,20 @@ ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
 # copies if different.
 macro(CREATE_SYMLINK SRC_FILE DEST_FILE)
   FILE(REMOVE ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
-  if(WIN32 AND NOT CYGWIN AND NOT MINGW)
+  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        ${CMAKE_CURRENT_BINARY_DIR}/${SRC_FILE} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}
-        COMMAND ${CMAKE_COMMAND} -E copy        ${CMAKE_CURRENT_BINARY_DIR}/${SRC_FILE} ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
-        DEPENDS ${PNG_LIB_NAME} ${PNG_LIB_NAME_STATIC}
+        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 MINGW)
-    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${SRC_FILE} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
-    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${SRC_FILE} ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
-  endif(WIN32 AND NOT CYGWIN AND NOT MINGW)
+  else(WIN32 AND NOT CYGWIN AND NOT MSYS)
+    get_filename_component(LINK_TARGET "${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()
 
 # libpng is a library so default to 'lib'
@@ -244,25 +243,25 @@ endif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
 # we use the same files like ./configure, so we have to set its vars
 # Only do this on Windows for Cygwin - the files don't make much sense outside
 # a UNIX look alike
-if(NOT WIN32 OR CYGWIN OR MINGW) 
-set(prefix      ${CMAKE_INSTALL_PREFIX})
-set(exec_prefix ${CMAKE_INSTALL_PREFIX})
-set(libdir      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
-set(includedir  ${CMAKE_INSTALL_PREFIX}/include)
-set(LIBS        "-lz -lm")
-configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
-  ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
-CREATE_SYMLINK(${PNGLIB_NAME}.pc libpng.pc)
+if(NOT WIN32 OR CYGWIN OR MINGW)
+  set(prefix      ${CMAKE_INSTALL_PREFIX})
+  set(exec_prefix ${CMAKE_INSTALL_PREFIX})
+  set(libdir      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
+  set(includedir  ${CMAKE_INSTALL_PREFIX}/include)
+  set(LIBS        "-lz -lm")
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
+  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(${PNGLIB_NAME}-config libpng-config)
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY)
+  CREATE_SYMLINK(${PNGLIB_NAME}-config libpng-config)
 endif(NOT WIN32 OR CYGWIN OR MINGW)
 
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.0beta04
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.18rc03
     VERSION 16.${PNGLIB_RELEASE}.0
     SOVERSION 16
     CLEAN_DIRECT_OUTPUT 1)
@@ -289,40 +288,34 @@ endif()
 
 # INSTALL
 if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
-  if(PNG_SHARED)
-    install(TARGETS ${PNG_LIB_NAME}
-        ${PNG_EXPORT_RULE}
-        RUNTIME DESTINATION bin
-        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
+  install(TARGETS ${PNG_LIB_TARGETS}
+      ${PNG_EXPORT_RULE}
+      RUNTIME DESTINATION bin
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
+  if(PNG_SHARED)
     # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
     if(CYGWIN OR MINGW)
        get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE})
-       get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
-       CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})
+       CREATE_SYMLINK(${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)
       get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME} LOCATION_${CMAKE_BUILD_TYPE})
-      get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
-      CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
+      CREATE_SYMLINK(${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)
-    install(TARGETS ${PNG_LIB_NAME_STATIC}
-        ${PNG_EXPORT_RULE}
-        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
     if(NOT WIN32 OR CYGWIN OR MINGW)
       get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME_STATIC} LOCATION_${CMAKE_BUILD_TYPE})
-      get_filename_component(BUILD_TARGET_FILE ${BUILD_TARGET_LOCATION} NAME)
-      CREATE_SYMLINK(${BUILD_TARGET_FILE} libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
+      CREATE_SYMLINK(${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)
@@ -334,10 +327,13 @@ if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
   install(FILES ${libpng_public_hdrs}   DESTINATION include/${PNGLIB_NAME})
 endif()
 if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL )
-  install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin)
-  install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
-          DESTINATION bin)
+  if(NOT WIN32 OR CYGWIN OR MINGW)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
 endif()
+
 if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
   # Install man pages
   if(NOT PNG_MAN_DIR)
@@ -346,14 +342,16 @@ 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
-  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc
-          DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
-  install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
-          DESTINATION bin)
-  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc
-          DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
-  install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
-          DESTINATION bin)
+  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
+            DESTINATION bin)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
 endif()
 
 # On versions of CMake that support it, create an export file CMake
@@ -362,7 +360,7 @@ if(PNG_EXPORT_RULE AND NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL )
   install(EXPORT libpng DESTINATION lib/libpng FILE lib${PNG_LIB_NAME}.cmake)
 endif()
 
-# what's with libpng-$VER%.txt and all the extra files?
+# what's with libpng-manual.txt and all the extra files?
 
 # UNINSTALL
 # do we need this?

INSTALL

@@ -1,32 +1,69 @@
 
 Installing libpng
 
+Contents
+
+   I. Simple installation
+  II. Rebuilding the configure scripts
+ III. Using scripts/makefile*
+  IV. Using cmake
+   V. Directory structure
+  VI. Building with project files
+ VII. Building with makefiles
+VIII. Configuring libpng for 16-bit platforms
+  IX. Configuring for DOS
+   X. Configuring for Medium Model
+  XI. Prepending a prefix to exported symbols
+ XII. Configuring for compiler xxx:
+XIII. Removing unwanted object code
+ XIV. Changes to the build and configuration of libpng in libpng-1.5.x
+  XV. Setjmp/longjmp issues
+ XVI. Other sources of information about libpng
+
+I. Simple installation
+
 On Unix/Linux and similar systems, you can simply type
 
     ./configure [--prefix=/path]
     make check
     make install
 
-and ignore the rest of this document.
+and ignore the rest of this document.  "/path" is the path to the directory
+where you want to install the libpng "lib", "include", and "bin"
+subdirectories.
 
-If configure does not work on your system and you have a reasonably
-up-to-date set of tools, running ./autogen.sh before running ./configure
-may fix the problem.  You can also run the individual commands in
-autogen.sh with the --force option, if supported by your version of
-the tools.  To be really sure that you aren't using any of the included
-pre-built scripts, you can do this:
+If you downloaded a GIT clone, you will need to run ./autogen.sh before
+running ./configure, to create "configure" and "Makefile.in" which are
+not included in the GIT repository.
+
+Note that "configure" is only included in the "*.tar" distributions and not
+in the "*.zip" or "*.7z" distributions. If you downloaded one of those
+distributions, see "Building with project files" or "Building with makefiles",
+below.
+
+II. Rebuilding the configure scripts
+
+If configure does not work on your system, or if you have a need to
+change configure.ac or Makefile.am, and you have a reasonably
+up-to-date set of tools, running ./autogen.sh in a git clone before
+running ./configure may fix the problem.  To be really sure that you
+aren't using any of the included pre-built scripts, you can do this:
 
     ./configure --enable-maintainer-mode
     make maintainer-clean
-    ./autogen.sh
+    ./autogen.sh --maintainer --clean
+    ./autogen.sh --maintainer
     ./configure [--prefix=/path] [other options]
     make
     make install
     make check
 
+III. Using scripts/makefile*
+
 Instead, you can use one of the custom-built makefiles in the
 "scripts" directory
 
+    cp scripts/pnglibconf.h.prebuilt pnglibconf.h
     cp scripts/makefile.system makefile
     make test
     make install
@@ -38,8 +75,28 @@ 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.  zlib can be placed in another directory,
-at the same level as libpng.
+wherever you got libpng; otherwise go to http://zlib.net.  You can place
+zlib in 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
+correspond to the version of zlib that's installed.
+
+If you wish to test with a particular zlib that is not first in the
+standard library search path, put ZLIBLIB, ZLIBINC, CPPFLAGS, LDFLAGS,
+and LD_LIBRARY_PATH in your environment before running "make test"
+or "make distcheck":
+
+ZLIBLIB=/path/to/lib export ZLIBLIB
+ZLIBINC=/path/to/include export ZLIBINC
+CPPFLAGS="-I$ZLIBINC" export CPPFLAGS
+LDFLAGS="-L$ZLIBLIB" export LDFLAGS
+LD_LIBRARY_PATH="$ZLIBLIB:$LD_LIBRARY_PATH" export LD_LIBRARY_PATH
+
+If you are using one of the makefile scripts, put ZLIBLIB and ZLIBINC
+in your environment and type "make ZLIBLIB=$ZLIBLIB ZLIBINC=$ZLIBINC test".
+
+IV. Using cmake
 
 If you want to use "cmake" (see www.cmake.org), type
 
@@ -47,13 +104,15 @@ If you want to use "cmake" (see www.cmake.org), type
    make
    make install
 
-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
-correspond to the version of zlib that's installed.
+As when using the simple configure method described above, "/path" points to
+the installation directory where you want to put the libpng "lib", "include",
+and "bin" subdirectories.
+
+V. Directory structure
 
 You can rename the directories that you downloaded (they
-might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.5"
-or "zlib125") so that you have directories called "zlib" and "libpng".
+might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.8"
+or "zlib128") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
 
@@ -61,8 +120,7 @@ Your directory structure should look like this:
       libpng  (this directory)
           INSTALL (this file)
           README
-          *.h
-          *.c
+          *.h, *.c  => libpng source files
           CMakeLists.txt    =>  "cmake" script
           configuration files:
              configure.ac, configure, Makefile.am, Makefile.in,
@@ -70,14 +128,10 @@ Your directory structure should look like this:
              libpng-config.in, aclocal.m4, config.h.in, config.sub,
              depcomp, install-sh, mkinstalldirs, test-pngtest.sh
           contrib
-             gregbook
-             pngminim
-             pngminus
-             pngsuite
-             visupng
+             arm-neon, conftest, examples, gregbook, libtests, pngminim,
+             pngminus, pngsuite, tools, visupng
           projects
-             visualc71
-             vstudio
+             cbuilder5, owatcom, visualc71, vstudio, xcode
           scripts
              makefile.*
              *.def (module definition files)
@@ -85,29 +139,31 @@ Your directory structure should look like this:
           pngtest.png
           etc.
       zlib
-          README
-          *.h
-          *.c
-          contrib
-          etc.
+          README, *.h, *.c contrib, etc.
 
 If the line endings in the files look funny, you may wish to get the other
 distribution of libpng.  It is available in both tar.gz (UNIX style line
 endings) and zip (DOS style line endings) formats.
 
+VI. Building with project files
+
 If you are building libpng with MSVC, you can enter the
-libpng projects\visualc6 or visualc71 directory and follow the instructions
+libpng projects\visualc71 or vstudio directory and follow the instructions
 in README.txt.
 
 Otherwise enter the zlib directory and follow the instructions in zlib/README,
 then come back here and run "configure" or choose the appropriate
 makefile.sys in the scripts directory.
 
+VII. Building with makefiles
+
 Copy the file (or files) that you need from the
 scripts directory into this directory, for example
 
    MSDOS example: copy scripts\makefile.msc makefile
-   UNIX example:    cp scripts/makefile.std makefile
+                  copy scripts\pnglibconf.h.prebuilt pnglibconf.h
+   UNIX example:  cp scripts/makefile.std makefile
+                  cp scripts/pnglibconf.h.prebuilt pnglibconf.h
 
 Read the makefile to see if you need to change any source or
 target directories to match your preferences.
@@ -130,6 +186,202 @@ do that, run "make install" in the zlib directory first if necessary).
 Some also allow you to run "make test-installed" after you have
 run "make install".
 
+VIII. Configuring libpng for 16-bit platforms
+
+You will want to look into zconf.h to tell zlib (and thus libpng) that
+it cannot allocate more than 64K at a time.  Even if you can, the memory
+won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
+
+IX. Configuring for DOS
+
+For DOS users who only have access to the lower 640K, you will
+have to limit zlib's memory usage via a png_set_compression_mem_level()
+call.  See zlib.h or zconf.h in the zlib library for more information.
+
+X. Configuring for Medium Model
+
+Libpng's support for medium model has been tested on most of the popular
+compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
+defined, and FAR gets defined to far in pngconf.h, and you should be
+all set.  Everything in the library (except for zlib's structure) is
+expecting far data.  You must use the typedefs with the p or pp on
+the end for pointers (or at least look at them and be careful).  Make
+note that the rows of data are defined as png_bytepp, which is
+an "unsigned char far * far *".
+
+XI. Prepending a prefix to exported symbols
+
+Starting with libpng-1.6.0, you can configure libpng (when using the
+"configure" script) to prefix all exported symbols by means of the
+configuration option "--with-libpng-prefix=FOO_", where FOO_ can be any
+string beginning with a letter and containing only uppercase
+and lowercase letters, digits, and the underscore (i.e., a C language
+identifier).  This creates a set of macros in pnglibconf.h, so this is
+transparent to applications; their function calls get transformed by
+the macros to use the modified names.
+
+XII. Configuring for compiler xxx:
+
+All includes for libpng are in pngconf.h.  If you need to add, change
+or delete an include, this is the place to do it.
+The includes that are not needed outside libpng are placed in pngpriv.h,
+which is only used by the routines inside libpng itself.
+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.
+
+XIII. Removing unwanted object code
+
+There are a bunch of #define's in pngconf.h that control what parts of
+libpng are compiled.  All the defines end in _SUPPORTED.  If you are
+never going to use a capability, you can change the #define to #undef
+before recompiling libpng and save yourself code and data space, or
+you can turn off individual capabilities with defines that begin with
+PNG_NO_.
+
+In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead.
+
+You can also turn all of the transforms and ancillary chunk capabilities
+off en masse with compiler directives that define
+PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
+or all four, along with directives to turn on any of the capabilities that
+you do want.  The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the
+extra transformations but still leave the library fully capable of reading
+and writing PNG files with all known public chunks. Use of the
+PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
+that is incapable of reading or writing ancillary chunks.  If you are
+not using the progressive reading capability, you can turn that off
+with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
+capability, which you'll still have).
+
+All the reading and writing specific code are in separate files, so the
+linker should only grab the files it needs.  However, if you want to
+make sure, or if you are building a stand alone library, all the
+reading files start with "pngr" and all the writing files start with "pngw".
+The files that don't match either (like png.c, pngtrans.c, etc.)
+are used for both reading and writing, and always need to be included.
+The progressive reader is in pngpread.c
+
+If you are creating or distributing a dynamically linked library (a .so
+or DLL file), you should not remove or disable any parts of the library,
+as this will cause applications linked with different versions of the
+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. 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
+majority of library users or builders; however, the few who configure libpng
+to a non-default feature set may need to change how this is done.
+
+There should be no need for library builders to alter build scripts if
+these use the distributed build support - configure or the makefiles -
+however, users of the makefiles may care to update their build scripts
+to build pnglibconf.h where the corresponding makefile does not do so.
+
+Building libpng with a non-default configuration has changed completely.
+The old method using pngusr.h should still work correctly even though the
+way pngusr.h is used in the build has been changed; however, library
+builders will probably want to examine the changes to take advantage of
+new capabilities and to simplify their build system.
+
+A. Specific changes to library configuration capabilities
+
+The exact mechanism used to control attributes of API functions has
+changed.  A single set of operating system independent macro definitions
+is used and operating system specific directives are defined in
+pnglibconf.h
+
+As part of this the mechanism used to choose procedure call standards on
+those systems that allow a choice has been changed.  At present this only
+affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems
+running on Intel processors.  As before, PNGAPI is defined where required
+to control the exported API functions; however, two new macros, PNGCBAPI
+and PNGCAPI, are used instead for callback functions (PNGCBAPI) and
+(PNGCAPI) for functions that must match a C library prototype (currently
+only png_longjmp_ptr, which must match the C longjmp function.)  The new
+approach is documented in pngconf.h
+
+Despite these changes, libpng 1.5.0 only supports the native C function
+calling standard on those platforms tested so far (__cdecl on Microsoft
+Windows).  This is because the support requirements for alternative
+calling conventions seem to no longer exist.  Developers who find it
+necessary to set PNG_API_RULE to 1 should advise the mailing list
+(png-mng-implement) of this and library builders who use Openwatcom and
+therefore set PNG_API_RULE to 2 should also contact the mailing list.
+
+B. Changes to the configuration mechanism
+
+Prior to libpng-1.5.0 library builders who needed to configure libpng
+had either to modify the exported pngconf.h header file to add system
+specific configuration or had to write feature selection macros into
+pngusr.h and cause this to be included into pngconf.h by defining
+PNG_USER_CONFIG. The latter mechanism had the disadvantage that an
+application built without PNG_USER_CONFIG defined would see the
+unmodified, default, libpng API and thus would probably fail to link.
+
+These mechanisms still work in the configure build and in any makefile
+build that builds pnglibconf.h, although the feature selection macros
+have changed somewhat as described above.  In 1.5.0, however, pngusr.h is
+processed only once, at the time the exported header file pnglibconf.h is
+built.  pngconf.h no longer includes pngusr.h; therefore, pngusr.h is ignored
+after the build of pnglibconf.h and it is never included in an application
+build.
+
+The formerly used alternative of adding a list of feature macros to the
+CPPFLAGS setting in the build also still works; however, the macros will be
+copied to pnglibconf.h and this may produce macro redefinition warnings
+when the individual C files are compiled.
+
+All configuration now only works if pnglibconf.h is built from
+scripts/pnglibconf.dfa.  This requires the program awk.  Brian Kernighan
+(the original author of awk) maintains C source code of that awk and this
+and all known later implementations (often called by subtly different
+names - nawk and gawk for example) are adequate to build pnglibconf.h.
+The Sun Microsystems (now Oracle) program 'awk' is an earlier version
+and does not work; this may also apply to other systems that have a
+functioning awk called 'nawk'.
+
+Configuration options are now documented in scripts/pnglibconf.dfa.  This
+file also includes dependency information that ensures a configuration is
+consistent; that is, if a feature is switched off, dependent features are
+also switched off.  As a recommended alternative to using feature macros in
+pngusr.h a system builder may also define equivalent options in pngusr.dfa
+(or, indeed, any file) and add that to the configuration by setting
+DFA_XTRA to the file name.  The makefiles in contrib/pngminim illustrate
+how to do this, and also illustrate a case where pngusr.h is still required.
+
+After you have built libpng, the definitions that were recorded in
+pnglibconf.h are available to your application (pnglibconf.h is included
+in png.h and gets installed alongside png.h and pngconf.h in your
+$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.
+
+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
+any platform where it is guaranteed to be thread-safe.  Therefore, if
+your application is going to be using multiple threads, you should
+configure libpng with PNG_NO_SETJMP in your pngusr.dfa file, with
+-DPNG_NO_SETJMP on your compile line, or with
+
+  #undef PNG_SETJMP_SUPPORTED
+
+in your pnglibconf.h or pngusr.h.
+
+Starting with libpng-1.6.0, the library included a "simplified API".
+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.
+
+XVI. 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
 libpng.3 and png.5.
@@ -147,7 +399,7 @@ CFLAGS="-Wall -O -funroll-loops \
 --with-pkgconfigdir=/usr/lib/pkgconfig --includedir=/usr/include
 
 You can alternatively specify --includedir=/usr/include, /usr/local/include,
-/usr/include/libpng%NN%, or whatever.
+/usr/include/libpng16, or whatever.
 
 If you find that the configure script is out-of-date or is not supporting
 your platform properly, try running autogen.sh to regenerate "configure",

LICENSE

@@ -10,21 +10,17 @@ this sentence.
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.0beta04, December 30, 2011, are
-Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
-distributed according to the same disclaimer and license as libpng-1.2.5
-with the following individual added to the list of Contributing Authors
-
-   Cosmin Truta
-
-libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
-Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+libpng versions 1.0.7, July 1, 2000, through 1.6.18rc03, July 13, 2015, are
+Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.0.6
-with the following individuals added to the list of Contributing Authors
+with the following individuals added to the list of Contributing Authors:
 
    Simon-Pierre Cadieux
    Eric S. Raymond
+   Mans Rullgard
+   Cosmin Truta
    Gilles Vollant
+   James Yu
 
 and with the following additions to the disclaimer:
 
@@ -36,17 +32,17 @@ and with the following additions to the disclaimer:
    the user.
 
 libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
-Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
-distributed according to the same disclaimer and license as libpng-0.96,
-with the following individuals added to the list of Contributing Authors:
+Copyright (c) 1998-2000 Glenn Randers-Pehrson, and are distributed according
+to the same disclaimer and license as libpng-0.96, with the following
+individuals added to the list of Contributing Authors:
 
    Tom Lane
    Glenn Randers-Pehrson
    Willem van Schaik
 
 libpng versions 0.89, June 1996, through 0.96, May 1997, are
-Copyright (c) 1996, 1997 Andreas Dilger
-Distributed according to the same disclaimer and license as libpng-0.88,
+Copyright (c) 1996-1997 Andreas Dilger, and are
+distributed according to the same disclaimer and license as libpng-0.88,
 with the following individuals added to the list of Contributing Authors:
 
    John Bowler
@@ -57,7 +53,7 @@ with the following individuals added to the list of Contributing Authors:
    Tom Tanner
 
 libpng versions 0.5, May 1995, through 0.88, January 1996, are
-Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
 
 For the purposes of this copyright and license, "Contributing Authors"
 is defined as the following set of individuals:
@@ -80,13 +76,13 @@ Permission is hereby granted to use, copy, modify, and distribute this
 source code, or portions hereof, for any purpose, without fee, subject
 to the following restrictions:
 
-1. The origin of this source code must not be misrepresented.
+  1. The origin of this source code must not be misrepresented.
 
-2. Altered versions must be plainly marked as such and must not
-   be misrepresented as being the original source.
+  2. Altered versions must be plainly marked as such and must not
+     be misrepresented as being the original source.
 
-3. This Copyright notice may not be removed or altered from any
-   source or altered source distribution.
+  3. This Copyright notice may not be removed or altered from any
+     source or altered source distribution.
 
 The Contributing Authors and Group 42, Inc. specifically permit, without
 fee, and encourage the use of this source code as a component to
@@ -94,18 +90,18 @@ supporting the PNG file format in commercial products.  If you use this
 source code in a product, acknowledgment is not required but would be
 appreciated.
 
-
 A "png_get_copyright" function is available, for convenient use in "about"
 boxes and the like:
 
-   printf("%s",png_get_copyright(NULL));
+   printf("%s", png_get_copyright(NULL));
 
 Also, the PNG logo (in PNG format, of course) is supplied in the
 files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
 
-Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
-certification mark of the Open Source Initiative.
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is
+a certification mark of the Open Source Initiative. OSI has not addressed
+the additional disclaimers inserted at version 1.0.7.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-December 30, 2011
+July 13, 2015

Makefile.am

@@ -4,27 +4,69 @@
 
 PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
 
-# libpng does not follow GNU file name conventions
-
-# "color-tests" requires automake 1.11.1 or later.  Enable it if you like,
-# to get red "FAIL" and green "PASS" notations during tests.
-# AUTOMAKE_OPTIONS = foreign color-tests
-AUTOMAKE_OPTIONS = foreign
+ACLOCAL_AMFLAGS = -I scripts
 
 # test programs - run on make check, make distcheck
-TESTS_ENVIRONMENT= srcdir=$(srcdir)
-check_PROGRAMS= pngtest
+check_PROGRAMS= pngtest pngunknown pngstest pngvalid pngimage
+
+# Utilities - installed
+bin_PROGRAMS= pngfix png-fix-itxt
+
+# This ensures that pnglibconf.h gets built at the start of 'make all' or
+# 'make check', but it does not add dependencies to the individual programs,
+# this is done below.
+#
+# IMPORTANT: always add the object modules of new programs to the list below
+# because otherwise the sequence 'configure; make new-program' will *sometimes*
+# result in the installed (system) pnglibconf.h being used and the result is
+# always wrong and always very confusing.
+BUILT_SOURCES = pnglibconf.h
+
 pngtest_SOURCES = pngtest.c
 pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-TESTS = test-pngtest.sh
 
-# Only do the following if the contrib directory is present.
-check_PROGRAMS+= pngvalid pngstest
 pngvalid_SOURCES = contrib/libtests/pngvalid.c
-pngstest_SOURCES = contrib/libtests/pngstest.c
 pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngstest_SOURCES = contrib/libtests/pngstest.c
 pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
-TESTS += test-pngvalid-simple.sh test-pngvalid-full.sh test-pngstest.sh
+
+pngunknown_SOURCES = contrib/libtests/pngunknown.c
+pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngimage_SOURCES = contrib/libtests/pngimage.c
+pngimage_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngfix_SOURCES = contrib/tools/pngfix.c
+pngfix_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+png_fix_itxt_SOURCES = contrib/tools/png-fix-itxt.c
+
+# Generally these are single line shell scripts to run a test with a particular
+# set of parameters:
+TESTS =\
+   tests/pngtest\
+   tests/pngvalid-gamma-16-to-8 tests/pngvalid-gamma-alpha-mode\
+   tests/pngvalid-gamma-background tests/pngvalid-gamma-expand16-alpha-mode\
+   tests/pngvalid-gamma-expand16-background\
+   tests/pngvalid-gamma-expand16-transform tests/pngvalid-gamma-sbit\
+   tests/pngvalid-gamma-threshold tests/pngvalid-gamma-transform\
+   tests/pngvalid-progressive-interlace-size\
+   tests/pngvalid-progressive-interlace-standard\
+   tests/pngvalid-progressive-interlace-transform\
+   tests/pngvalid-progressive-standard tests/pngvalid-standard\
+   tests/pngstest-0g01 tests/pngstest-0g02 tests/pngstest-0g04\
+   tests/pngstest-0g08 tests/pngstest-0g16 tests/pngstest-2c08\
+   tests/pngstest-2c16 tests/pngstest-3p01 tests/pngstest-3p02\
+   tests/pngstest-3p04 tests/pngstest-3p08 tests/pngstest-4a08\
+   tests/pngstest-4a16 tests/pngstest-6a08 tests/pngstest-6a16\
+   tests/pngstest-error tests/pngunknown-IDAT\
+   tests/pngunknown-discard tests/pngunknown-if-safe tests/pngunknown-sAPI\
+   tests/pngunknown-sTER tests/pngunknown-save tests/pngunknown-vpAg\
+   tests/pngimage-quick tests/pngimage-full
+
+# These tests are expected, and required, to fail:
+XFAIL_TESTS = tests/pngstest-error
 
 # man pages
 dist_man_MANS= libpng.3 libpngpf.3 png.5
@@ -40,10 +82,11 @@ 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
+	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
 
 if PNG_ARM_NEON
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/filter_neon.S
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
+	arm/filter_neon.S arm/filter_neon_intrinsics.c
 endif
 
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
@@ -76,24 +119,33 @@ nodist_pkginclude_HEADERS= pnglibconf.h
 pkgconfigdir = @pkgconfigdir@
 pkgconfig_DATA = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc
 
-#extra source distribution files.
+# Extra source distribution files, '${srcdir}' is used below to stop build files
+# from those directories being included.  This only works if the configure is
+# not done in the source directory!
 EXTRA_DIST= \
 	ANNOUNCE CHANGES INSTALL LICENSE README TODO \
 	pngtest.png pngbar.png pngnow.png pngbar.jpg autogen.sh \
 	${srcdir}/contrib ${srcdir}/projects ${srcdir}/scripts \
-	$(TESTS) \
+	$(TESTS) $(XFAIL_TESTS) tests/pngstest \
 	CMakeLists.txt example.c libpng-manual.txt
 
-SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk scripts/pnglibconf.dfn
+SCRIPT_CLEANFILES=scripts/*.out scripts/*.chk
 
 CLEANFILES= *.tf? pngout.png libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.pc \
 	libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config libpng.vers libpng.sym \
-	check.new pnglibconf.* symbols.new pngtest-log.txt \
+	check.new pnglibconf.h pngprefix.h symbols.new pngtest-log.txt \
+	pnglibconf.out pnglibconf.c pnglibconf.pre pnglibconf.dfn \
 	$(SCRIPT_CLEANFILES)
 
 MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess config.h.in \
 config.sub configure depcomp install-sh ltmain.sh missing
 
+# PNG_COPTS give extra options for the C compiler to be used on all compilation
+# steps (unless targe_CFLAGS is specified; that will take precedence over
+# AM_CFLAGS)
+PNG_COPTS = @PNG_COPTS@
+AM_CFLAGS = ${PNG_COPTS}
+
 # DFNCPP is normally just CPP - the C preprocessor - but on Solaris and maybe
 # other operating systems (NeXT?) the C preprocessor selected by configure
 # checks input tokens for validity - effectively it performs part of the ANSI-C
@@ -101,7 +153,7 @@ config.sub configure depcomp install-sh ltmain.sh missing
 # checks for this and sets DFNCPP appropriately.
 DFNCPP = @DFNCPP@
 
-SUFFIXES = .chk .dfn .out
+SUFFIXES = .chk .out
 
 $(PNGLIB_BASENAME).pc: libpng.pc
 	cp libpng.pc $@
@@ -110,7 +162,9 @@ $(PNGLIB_BASENAME)-config: libpng-config
 	cp libpng-config $@
 
 scripts/sym.out scripts/vers.out: png.h pngconf.h pnglibconf.h
+scripts/prefix.out: png.h pngconf.h pnglibconf.out
 scripts/symbols.out: png.h pngconf.h $(srcdir)/scripts/pnglibconf.h.prebuilt
+scripts/intprefix.out: pnglibconf.h
 
 libpng.sym: scripts/sym.out
 	rm -f $@
@@ -118,19 +172,59 @@ libpng.sym: scripts/sym.out
 libpng.vers: scripts/vers.out
 	rm -f $@
 	cp $? $@
+
+if DO_PNG_PREFIX
+# Rename functions in scripts/prefix.out with a PNG_PREFIX prefix.
+# Rename macros in scripts/macro.lst from PNG_PREFIXpng_ to PNG_ (the actual
+# implementation of the macro).
+pnglibconf.h: pnglibconf.out scripts/prefix.out scripts/macro.lst
+	rm -f $@
+	$(AWK) 's==0 && NR>1{print prev}\
+	   s==0{prev=$$0}\
+	   s==1{print "#define", $$1, "@PNG_PREFIX@" $$1}\
+	   s==2{print "#define @PNG_PREFIX@png_" $$1, "PNG_" $$1}\
+	   END{print prev}' s=0 pnglibconf.out s=1 scripts/prefix.out\
+	   s=2 ${srcdir}/scripts/macro.lst >pnglibconf.tf8
+	mv pnglibconf.tf8 $@
+
+pngprefix.h: scripts/intprefix.out
+	rm -f pngprefix.tf1
+	$(AWK) '{print "#define", $$1, "@PNG_PREFIX@" $$1}' $? >pngprefix.tf1
+	mv pngprefix.tf1 $@
+else
 pnglibconf.h: pnglibconf.out
 	rm -f $@
 	cp $? $@
+
+pngprefix.h: # is empty
+	:>$@
+endif
+
 $(srcdir)/scripts/pnglibconf.h.prebuilt:
 	@echo "Attempting to build $@" >&2
 	@echo "This is a machine generated file, but if you want to make" >&2
-	@echo "a new one simply make 'scripts/pnglibconf.out' and copy that" >&2
+	@echo "a new one simply make 'scripts/pnglibconf.out', copy that" >&2
+	@echo "AND set PNG_ZLIB_VERNUM to 0 (you MUST do this)" >&2
 	@exit 1
 
 # The following is necessary to ensure that the local pnglibconf.h is used, not
 # an installed one (this can happen immediately after on a clean system if
-# 'make test' is the first thing the user does.)
-contrib/libtests/pngstest.o contrib/libtests/pngvalid.o pngtest.o: pnglibconf.h
+# 'make test' is the first thing the user does.)  Only files which include
+# one of the png source files (typically png.h or pngpriv.h) need to be listed
+# here:
+pngtest.o: pnglibconf.h
+
+contrib/libtests/makepng.o: pnglibconf.h
+contrib/libtests/pngstest.o: pnglibconf.h
+contrib/libtests/pngunknown.o: pnglibconf.h
+contrib/libtests/pngimage.o: pnglibconf.h
+contrib/libtests/pngvalid.o: pnglibconf.h
+contrib/libtests/readpng.o: pnglibconf.h
+contrib/libtests/tarith.o: pnglibconf.h
+contrib/libtests/timepng.o: pnglibconf.h
+
+contrib/tools/makesRGB.o: pnglibconf.h
+contrib/tools/pngfix.o: pnglibconf.h
 
 # We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
 # be built with PNG_USE_READ_MACROS; this prevents the read macros from
@@ -140,24 +234,25 @@ SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0'\
 		-DSYMBOL_PREFIX='$(SYMBOL_PREFIX)'\
 		-DPNG_NO_USE_READ_MACROS -DPNG_BUILDING_SYMBOL_TABLE
 
-.dfn.out:
-	rm -f $@ $*.c $*.tf[123]
-	test -d scripts || mkdir scripts
-	echo '#include "$<"' >$*.c
-	$(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)\
-	    $(CPPFLAGS) $(SYMBOL_CFLAGS) $*.c > $*.tf1
-	$(SED) -n -e 's|^.*PNG_DEFN_MAGIC *-\(.*\)- *PNG_DEFN_END.*$$|\1|p'\
-	    $*.tf1 >$*.tf2
-	$(SED) -e 's| *PNG_JOIN *||g' -e 's| *$$||' $*.tf2 >$*.tf3
-	rm -f $*.c $*.tf[12]
-	mv $*.tf3 $@
+if DO_PNG_PREFIX
+SYMBOL_CFLAGS += -DPNG_PREFIX='@PNG_PREFIX@'
+endif
 
-# The .dfn file for pnglibconf.h is machine generated
-pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
+.c.out:
+	rm -f $@ $*.tf[12]
+	test -d scripts || mkdir scripts || test -d scripts
+	$(DFNCPP) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)\
+	    $(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)
 	rm -f $@ $*.tf[45]
 	$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf4 version=search\
 	    ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
-	    $(DFA_XTRA) 1>&2
+	    ${srcdir}/pngusr.dfa $(DFA_XTRA) 1>&2
 	$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf5 $*.tf4 1>&2
 	rm $*.tf4
 	mv $*.tf5 $@
@@ -173,7 +268,7 @@ scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.ou
 
 # used on demand to regenerate the standard header, CPPFLAGS should
 # be empty - no non-standard defines
-scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
+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" |\
@@ -186,7 +281,7 @@ scripts/pnglibconf.dfn: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
 	mv pnglibconf.tf7 $@
 
 $(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS): png.h pngconf.h \
-	pnglibconf.h pngpriv.h pngdebug.h pnginfo.h pngstruct.h
+	pnglibconf.h pngpriv.h pngdebug.h pnginfo.h pngstruct.h pngprefix.h
 
 test: check-am
 
@@ -197,33 +292,76 @@ check: scripts/symbols.chk
 dist-hook:
 	cd '$(top_distdir)'; rm -f $(SCRIPT_CLEANFILES)
 
-# install the .../include headers as links to the new ones
-install-data-hook:
-	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h pnglibconf.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/png.h png.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/pngconf.h \
-		pngconf.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/pnglibconf.h \
-		pnglibconf.h
-	cd $(DESTDIR)$(pkgconfigdir); rm -f libpng.pc
-	cd $(DESTDIR)$(pkgconfigdir); $(LN_S) $(PNGLIB_BASENAME).pc libpng.pc
+# Make links between installed files with release-specific names and the generic
+# file names.  If this install rule is run the generic names will be deleted and
+# recreated - this has obvious issues for systems with multiple installations.
 
-# do evil things to libpng to cause libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@ to be used
-install-exec-hook:
-	cd $(DESTDIR)$(bindir); rm -f libpng-config
-	cd $(DESTDIR)$(bindir); $(LN_S) $(PNGLIB_BASENAME)-config libpng-config
-	@set -x;\
-	cd $(DESTDIR)$(libdir);\
-	for ext in a la so so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@ sl dylib dll.a; do\
-		rm -f libpng.$$ext;\
-                if test -f $(PNGLIB_BASENAME).$$ext; then\
-                       $(LN_S) $(PNGLIB_BASENAME).$$ext libpng.$$ext;\
-                fi;\
+install-header-links:
+	@set -ex; cd '$(DESTDIR)$(includedir)'; for f in $(HEADERS); do \
+	   rm -f "$$f"; $(LN_S) "$(PNGLIB_BASENAME)/$$f" "$$f"; done
+
+uninstall-header-links:
+	cd '$(DESTDIR)$(includedir)'; rm -f $(HEADERS)
+
+install-libpng-pc:
+	@set -ex; cd '$(DESTDIR)$(pkgconfigdir)'; rm -f libpng.pc; \
+	   $(LN_S) '$(PNGLIB_BASENAME).pc' libpng.pc
+
+uninstall-libpng-pc:
+	rm -f '$(DESTDIR)$(pkgconfigdir)/libpng.pc'
+
+# EXT_LIST is a list of the possibly library directory extensions, this exists
+# because we can't find a good way of discovering the file extensions that are
+# actually installed on a given system, so instead we check for every extension
+# we have seen.
+
+EXT_LIST = a dll.a so so.@PNGLIB_MAJOR@@PNGLIB_MINOR@.@PNGLIB_RELEASE@ la sl dylib
+
+install-library-links:
+	@set -x; cd '$(DESTDIR)$(libdir)';\
+	for ext in $(EXT_LIST); do\
+	   rm -f "libpng.$$ext";\
+           if test -f "$(PNGLIB_BASENAME).$$ext"; then\
+              $(LN_S) "$(PNGLIB_BASENAME).$$ext" "libpng.$$ext" || exit 1;\
+           fi;\
 	done
 
-uninstall-hook:
-	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h pnglibconf.h
-	rm -f $(DESTDIR)$(pkgconfigdir)/libpng.pc
-	rm -f $(DESTDIR)$(bindir)/libpng-config
-	rm -f $(DESTDIR)$(libdir)/libpng.a
-	rm -f $(DESTDIR)$(libdir)/libpng.la
+uninstall-library-links:
+	@set -x; cd '$(DESTDIR)$(libdir)'; for ext in $(EXT_LIST); do\
+	   rm -f "libpng.$$ext"; done
+
+install-libpng-config:
+	@set -ex; cd '$(DESTDIR)$(bindir)'; rm -f libpng-config; \
+	   $(LN_S) '$(PNGLIB_BASENAME)-config' libpng-config
+
+uninstall-libpng-config:
+	rm -f '$(DESTDIR)$(bindir)/libpng-config'
+
+if DO_INSTALL_LINKS
+# If --enable-unversioned-links is specified the header and lib file links
+# will be automatically made on a 'make install':
+
+install-data-hook: install-header-links
+uninstall-hook: uninstall-header-links
+install-exec-hook: install-library-links
+uninstall-hook: uninstall-library-links
+endif
+
+if DO_INSTALL_LIBPNG_PC
+# Likewise, --install-pc causes libpng.pc to be constructed:
+
+install-data-hook: install-libpng-pc
+uninstall-hook: uninstall-libpng-pc
+endif
+
+if DO_INSTALL_LIBPNG_CONFIG
+# And --install-config:
+
+install-exec-hook: install-libpng-config
+uninstall-hook: uninstall-libpng-config
+endif
+
+# The following addition ensures that 'make all' always builds the test programs
+# too.  It used to, but some change either in libpng or configure stopped this
+# working.
+all-am: $(check_PROGRAMS)

README

@@ -1,11 +1,11 @@
-README for libpng version 1.6.0beta04 - December 30, 2011 (shared library 16.0)
+README for libpng version 1.6.18rc03 - July 13, 2015 (shared library 16.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
 
-Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
-libpng-*.tar.xz or libpng-*.tar.bz2 if you want UNIX-style line endings
-in the text files, or lpng*.zip if you want DOS-style line endings.
+Libpng comes in several distribution formats.  Get libpng-*.tar.gz or
+libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
+or lpng*.7z or lpng*.zip if you want DOS-style line endings.
 
 Version 0.89 was the first official release of libpng.  Don't let the
 fact that it's the first release fool you.  The libpng library has been in
@@ -23,18 +23,25 @@ earlier versions if you are using a shared library.  The type of the
 png_uint_32, which will affect shared-library applications that use
 this function.
 
-To avoid problems with changes to the internals of png_info_struct,
+To avoid problems with changes to the internals of png info_struct,
 new APIs have been made available in 0.95 to avoid direct application
 access to info_ptr.  These functions are the png_set_<chunk> and
 png_get_<chunk> functions.  These functions should be used when
 accessing/storing the info_struct data, rather than manipulating it
 directly, to avoid such problems in the future.
 
-It is important to note that the APIs do not make current programs
+It is important to note that the APIs did not make current programs
 that access the info struct directly incompatible with the new
-library.  However, it is strongly suggested that new programs use
-the new APIs (as shown in example.c and pngtest.c), and older programs
-be converted to the new format, to facilitate upgrades in the future.
+library, through libpng-1.2.x.  In libpng-1.4.x, which was meant to
+be a transitional release, members of the png_struct and the
+info_struct can still be accessed, but the compiler will issue a
+warning about deprecated usage.  Since libpng-1.5.0, direct access
+to these structs is not allowed, and the definitions of the structs
+reside in private pngstruct.h and pnginfo.h header files that are not
+accessible to applications.  It is strongly suggested that new
+programs use the new APIs (as shown in example.c and pngtest.c), and
+older programs be converted to the new format, to facilitate upgrades
+in the future.
 ****
 
 Additions since 0.90 include the ability to compile libpng as a
@@ -77,17 +84,21 @@ compression library that is useful for more things than just PNG files.
 You can use zlib as a drop-in replacement for fread() and fwrite() if
 you are so inclined.
 
-zlib should be available at the same place that libpng is, or at.
-ftp://ftp.info-zip.org/pub/infozip/zlib
+zlib should be available at the same place that libpng is, or at zlib.net.
 
 You may also want a copy of the PNG specification.  It is available
 as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
 these at http://www.libpng.org/pub/png/documents/
 
 This code is currently being archived at libpng.sf.net in the
-[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
-at GO GRAPHSUP.  If you can't find it in any of those places,
-e-mail me, and I'll help you find it.
+[DOWNLOAD] area, and at ftp://ftp.simplesystems.org.  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
+Number (ECCN) for libpng is EAR99, which means not subject to export
+controls or International Traffic in Arms Regulations (ITAR) because it
+is open source, publicly available software, that does not contain any
+encryption software.  See the EAR, paragraphs 734.3(b)(3) and 734.7(b).
 
 If you have any code changes, requests, problems, etc., please e-mail
 them to me.  Also, I'd appreciate any make files or project files,
@@ -105,7 +116,7 @@ based in a large way on Guy's and Andreas' earlier work), and the PNG
 development group.
 
 Send comments/corrections/commendations to png-mng-implement at
-lists.sourceforge.net (subscription required; visit 
+lists.sourceforge.net (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
 to subscribe) or to glennrp at users.sourceforge.net
 
@@ -123,7 +134,7 @@ and ...".  If in doubt, send questions to me.  I'll bounce them
 to others, if necessary.
 
 Please do not send suggestions on how to change PNG.  We have
-been discussing PNG for sixteen years now, and it is official and
+been discussing PNG for twenty years now, and it is official and
 finished.  If you have suggestions for libpng, however, I'll
 gladly listen.  Even if your suggestion is not used immediately,
 it may be used later.
@@ -167,23 +178,25 @@ Files in this distribution:
       pngwrite.c    =>  High-level write functions
       pngwtran.c    =>  Write data transformations
       pngwutil.c    =>  Write utility functions
+      arm           =>  Contains optimized code for the ARM platform
       contrib       =>  Contributions
+       examples         =>  Example programs
        gregbook         =>  source code for PNG reading and writing, from
                             Greg Roelofs' "PNG: The Definitive Guide",
                             O'Reilly, 1999
-       msvctest     =>  Builds and runs pngtest using a MSVC workspace
-       pngminus     =>  Simple pnm2png and png2pnm programs
-       pngsuite     =>  Test images
-       visupng      =>  Contains a MSVC workspace for VisualPng
+       libtests         =>  Test programs
+       pngminim         =>  Minimal decoder, encoder, and progressive decoder
+                            programs demonstrating use of pngusr.dfa
+       pngminus         =>  Simple pnm2png and png2pnm programs
+       pngsuite         =>  Test images
+       tools            =>  Various tools
+       visupng          =>  Contains a MSVC workspace for VisualPng
       projects      =>  Contains project files and workspaces for
                         building a DLL
-       cbuilder5        =>  Contains a Borland workspace for building
-                            libpng and zlib
-       visualc6         =>  Contains a Microsoft Visual C++ (MSVC)
-                            workspace for building libpng and zlib
+       owatcom          =>  Contains a WATCOM project for building libpng
        visualc71        =>  Contains a Microsoft Visual C++ (MSVC)
                             workspace for building libpng and zlib
-       xcode            =>  Contains an Apple xcode
+       vstudio          =>  Contains a Microsoft Visual C++ (MSVC)
                             workspace for building libpng and zlib
       scripts       =>  Directory containing scripts for building libpng:
                             (see scripts/README.txt for the list of scripts)

TODO

@@ -6,10 +6,12 @@ Better C++ wrapper/full C++ implementation?
 Fix problem with C++ and EXTERN "C".
 cHRM transformation.
 Remove setjmp/longjmp usage in favor of returning error codes.
+Palette creation.
 Add "grayscale->palette" transformation and "palette->grayscale" detection.
 Improved dithering.
 Multi-lingual error and warning message support.
 Complete sRGB transformation (presently it simply uses gamma=0.45455).
+Make profile checking optional via a png_set_something() call.
 Man pages for function calls.
 Better documentation.
 Better filter selection

arm/arm_init.c

@@ -0,0 +1,134 @@
+
+/* arm_init.c - NEON optimised filter functions
+ *
+ * Copyright (c) 2014 Glenn Randers-Pehrson
+ * Written by Mans Rullgard, 2011.
+ * 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
+ */
+/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
+ * called.
+ */
+#define _POSIX_SOURCE 1
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+
+#if PNG_ARM_NEON_OPT > 0
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
+/* WARNING: it is strongly recommended that you do not build libpng with
+ * run-time checks for CPU features if at all possible.  In the case of the ARM
+ * NEON instructions there is no processor-specific way of detecting the
+ * presence of the required support, therefore run-time detection is extremely
+ * OS specific.
+ *
+ * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing
+ * a fragment of C source code which defines the png_have_neon function.  There
+ * are a number of implementations in contrib/arm-neon, but the only one that
+ * has partial support is contrib/arm-neon/linux.c - a generic Linux
+ * implementation which reads /proc/cpufino.
+ */
+#ifndef PNG_ARM_NEON_FILE
+#  ifdef __linux__
+#     define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
+#  endif
+#endif
+
+#ifdef PNG_ARM_NEON_FILE
+
+#include <signal.h> /* for sig_atomic_t */
+static int png_have_neon(png_structp png_ptr);
+#include PNG_ARM_NEON_FILE
+
+#else  /* PNG_ARM_NEON_FILE */
+#  error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks"
+#endif /* PNG_ARM_NEON_FILE */
+#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
+#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
+#  error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
+#endif
+
+void
+png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
+{
+   /* The switch statement is compiled in for ARM_NEON_API, the call to
+    * png_have_neon is compiled in for ARM_NEON_CHECK.  If both are defined
+    * the check is only performed if the API has not set the NEON option on
+    * or off explicitly.  In this case the check controls what happens.
+    *
+    * If the CHECK is not compiled in and the option is UNSET the behavior prior
+    * to 1.6.7 was to use the NEON code - this was a bug caused by having the
+    * wrong order of the 'ON' and 'default' cases.  UNSET now defaults to OFF,
+    * as documented in png.h
+    */
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+   switch ((pp->options >> PNG_ARM_NEON) & 3)
+   {
+      case PNG_OPTION_UNSET:
+         /* Allow the run-time check to execute if it has been enabled -
+          * thus both API and CHECK can be turned on.  If it isn't supported
+          * this case will fall through to the 'default' below, which just
+          * returns.
+          */
+#endif /* PNG_ARM_NEON_API_SUPPORTED */
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
+         {
+            static volatile sig_atomic_t no_neon = -1; /* not checked */
+
+            if (no_neon < 0)
+               no_neon = !png_have_neon(pp);
+
+            if (no_neon)
+               return;
+         }
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+         break;
+#endif
+#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
+
+#ifdef PNG_ARM_NEON_API_SUPPORTED
+      default: /* OFF or INVALID */
+         return;
+
+      case PNG_OPTION_ON:
+         /* Option turned on */
+         break;
+   }
+#endif
+
+   /* IMPORTANT: any new external functions used here must be declared using
+    * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the
+    * 'prefix' option to configure works:
+    *
+    *    ./configure --with-libpng-prefix=foobar_
+    *
+    * Verify you have got this right by running the above command, doing a build
+    * and examining pngprefix.h; it must contain a #define for every external
+    * function you add.  (Notice that this happens automatically for the
+    * initialization function.)
+    */
+   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
+
+   if (bpp == 3)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+         png_read_filter_row_paeth3_neon;
+   }
+
+   else if (bpp == 4)
+   {
+      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
+      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+          png_read_filter_row_paeth4_neon;
+   }
+}
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* READ */

arm/filter_neon.S

@@ -1,18 +1,36 @@
 
 /* filter_neon.S - NEON optimised filter functions
  *
- * Copyright (c) 2011 Glenn Randers-Pehrson
+ * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
+ * 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
  */
 
+/* This is required to get the symbol renames, which are #defines, and the
+ * definitions (or not) of PNG_ARM_NEON_OPT and PNG_ARM_NEON_IMPLEMENTATION.
+ */
+#define PNG_VERSION_INFO_ONLY
+#include "../pngpriv.h"
+
 #if defined(__linux__) && defined(__ELF__)
 .section .note.GNU-stack,"",%progbits /* mark stack as non-executable */
 #endif
 
+#ifdef PNG_READ_SUPPORTED
+
+/* Assembler NEON support - only works for 32-bit ARM (i.e. it does not work for
+ * ARM64).  The code in arm/filter_neon_intrinsics.c supports ARM64, however it
+ * only works if -mfpu=neon is specified on the GCC command line.  See pngpriv.h
+ * for the logic which sets PNG_USE_ARM_NEON_ASM:
+ */
+#if PNG_ARM_NEON_IMPLEMENTATION == 2 /* hand-coded assembler */
+
+#if PNG_ARM_NEON_OPT > 0
+
 #ifdef __ELF__
 #   define ELF
 #else
@@ -29,6 +47,13 @@ ELF     .size   \name, . - \name
         .purgem endfunc
     .endm
         .text
+
+        /* Explicitly specifying alignment here because some versions of
+         * GAS don't align code correctly.  This is harmless in correctly
+         * written versions of GAS.
+         */
+        .align 2
+
     .if \export
         .global \name
     .endif
@@ -223,3 +248,6 @@ func    png_read_filter_row_paeth3_neon, export=1
 
         pop             {r4,pc}
 endfunc
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */
+#endif /* READ */

arm/filter_neon_intrinsics.c

@@ -0,0 +1,373 @@
+
+/* filter_neon_intrinsics.c - NEON optimised filter functions
+ *
+ * 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 1.6.16 [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"
+
+#ifdef PNG_READ_SUPPORTED
+
+/* This code requires -mfpu=neon on the command line: */
+#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
+
+#include <arm_neon.h>
+
+/* libpng row pointers are not necessarily aligned to any particular boundary,
+ * however this code will only work with appropriate alignment.  arm/arm_init.c
+ * checks for this (and will not compile unless it is done). This code uses
+ * variants of png_aligncast to avoid compiler warnings.
+ */
+#define png_ptr(type,pointer) png_aligncast(type *,pointer)
+#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer)
+
+/* The following relies on a variable 'temp_pointer' being declared with type
+ * 'type'.  This is written this way just to hide the GCC strict aliasing
+ * warning; note that the code is safe because there never is an alias between
+ * the input and output pointers.
+ */
+#define png_ldr(type,pointer)\
+   (temp_pointer = png_ptr(type,pointer), *temp_pointer)
+
+#if PNG_ARM_NEON_OPT > 0
+
+void
+png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint8x16_t qrp, qpp;
+
+      qrp = vld1q_u8(rp);
+      qpp = vld1q_u8(pp);
+      qrp = vaddq_u8(qrp, qpp);
+      vst1q_u8(rp, qrp);
+   }
+}
+
+void
+png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp = vld1q_u8(rp);
+   uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp);
+   uint8x8x2_t vrp = *vrpt;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop;)
+   {
+      uint8x8_t vtmp1, vtmp2;
+      uint32x2_t *temp_pointer;
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vadd_u8(vdest.val[0], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vdest.val[2] = vadd_u8(vdest.val[1], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t, &vtmp);
+      vrp = *vrpt;
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+
+   PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16)
+   {
+      uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      uint8x8x4_t vrp = *vrpt;
+      uint32x2x4_t *temp_pointer;
+
+      vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]);
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+
+   PNG_UNUSED(prev_row)
+}
+
+void
+png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t *vrpt;
+   uint8x8x2_t vrp;
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrpt = png_ptr(uint8x8x2_t,&vtmp);
+   vrp = *vrpt;
+
+   for (; rp < rp_stop; pp += 12)
+   {
+      uint8x8_t vtmp1, vtmp2, vtmp3;
+
+      uint8x8x2_t *vppt;
+      uint8x8x2_t vpp;
+
+      uint32x2_t *temp_pointer;
+
+      vtmp = vld1q_u8(pp);
+      vppt = png_ptr(uint8x8x2_t,&vtmp);
+      vpp = *vppt;
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t,&vtmp);
+      vrp = *vrpt;
+
+      vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp3);
+
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint32x2x4_t vtmp;
+      uint8x8x4_t *vrpt, *vppt;
+      uint8x8x4_t vrp, vpp;
+      uint32x2x4_t *temp_pointer;
+
+      vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      vrp = *vrpt;
+      vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+      vppt = png_ptr(uint8x8x4_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+}
+
+static uint8x8_t
+paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c)
+{
+   uint8x8_t d, e;
+   uint16x8_t p1, pa, pb, pc;
+
+   p1 = vaddl_u8(a, b); /* a + b */
+   pc = vaddl_u8(c, c); /* c * 2 */
+   pa = vabdl_u8(b, c); /* pa */
+   pb = vabdl_u8(a, c); /* pb */
+   pc = vabdq_u16(p1, pc); /* pc */
+
+   p1 = vcleq_u16(pa, pb); /* pa <= pb */
+   pa = vcleq_u16(pa, pc); /* pa <= pc */
+   pb = vcleq_u16(pb, pc); /* pb <= pc */
+
+   p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */
+
+   d = vmovn_u16(pb);
+   e = vmovn_u16(p1);
+
+   d = vbsl_u8(d, b, c);
+   e = vbsl_u8(e, a, d);
+
+   return e;
+}
+
+void
+png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_const_bytep pp = prev_row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+
+   uint8x16_t vtmp;
+   uint8x8x2_t *vrpt;
+   uint8x8x2_t vrp;
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   vtmp = vld1q_u8(rp);
+   vrpt = png_ptr(uint8x8x2_t,&vtmp);
+   vrp = *vrpt;
+
+   for (; rp < rp_stop; pp += 12)
+   {
+      uint8x8x2_t *vppt;
+      uint8x8x2_t vpp;
+      uint8x8_t vtmp1, vtmp2, vtmp3;
+      uint32x2_t *temp_pointer;
+
+      vtmp = vld1q_u8(pp);
+      vppt = png_ptr(uint8x8x2_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
+      vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
+      vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6);
+      vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6);
+      vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2);
+      vdest.val[2] = vadd_u8(vdest.val[2], vtmp1);
+
+      vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
+      vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
+
+      vtmp = vld1q_u8(rp + 12);
+      vrpt = png_ptr(uint8x8x2_t,&vtmp);
+      vrp = *vrpt;
+
+      vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3);
+      vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
+
+      vlast = vtmp2;
+
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
+      rp += 3;
+      vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
+      rp += 3;
+   }
+}
+
+void
+png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
+   png_const_bytep prev_row)
+{
+   png_bytep rp = row;
+   png_bytep rp_stop = row + row_info->rowbytes;
+   png_const_bytep pp = prev_row;
+
+   uint8x8_t vlast = vdup_n_u8(0);
+   uint8x8x4_t vdest;
+   vdest.val[3] = vdup_n_u8(0);
+
+   for (; rp < rp_stop; rp += 16, pp += 16)
+   {
+      uint32x2x4_t vtmp;
+      uint8x8x4_t *vrpt, *vppt;
+      uint8x8x4_t vrp, vpp;
+      uint32x2x4_t *temp_pointer;
+
+      vtmp = vld4_u32(png_ptr(uint32_t,rp));
+      vrpt = png_ptr(uint8x8x4_t,&vtmp);
+      vrp = *vrpt;
+      vtmp = vld4_u32(png_ptrc(uint32_t,pp));
+      vppt = png_ptr(uint8x8x4_t,&vtmp);
+      vpp = *vppt;
+
+      vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
+      vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
+      vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]);
+      vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
+      vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]);
+      vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
+      vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]);
+      vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
+
+      vlast = vpp.val[3];
+
+      vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
+   }
+}
+
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */
+#endif /* READ */

autogen.sh

@@ -1,34 +1,225 @@
 #! /bin/sh
-# a quick hack script to generate necessary files from 
-# auto* tools.
 #
-# WARNING: if you run this you will change the versions
-# of the tools which are used and, maybe, required!
+# Run 'autoreconf' to build 'configure', 'Makefile.in' and other configure
+# control files.
+#
+# The first time this is run on a GIT checkout the only files that exist are
+# configure.ac and Makefile.am; all of the autotools support scripts are
+# missing.  They are instantiated with autoreconf --force --install.
+#
+# For regular ("tarball") distributions all the files should exist.  We do not
+# want them to be updated *under any circumstances*.  It should never be
+# necessary to run autogen.sh because ./configure --enable-maintainer-mode says
+# what to do if Makefile.am or configure.ac are changed.
+#
+# It is *probably* OK to update the files on a GIT checkout, because they have
+# come from the local tools, but leave that to the user who is assumed to know
+# whether it is ok or required.
+#
+# This script is intended to work without arguments, there are, however, hidden
+# arguments (a) for use while testing the script and (b) to fix up systems that
+# have been broken.  If (b) is required the script prompts for the correct
+# options.  For this reason the options are *NOT* documented in the help; this
+# is deliberate; UTSL.
+#
+clean=
+maintainer=
+while test $# -gt 0
+do
+   case "$1" in
+      --maintainer)
+         maintainer=1;;
 
-# You can define your own replacements in your environment.
-# $AUTOCONF,  $AUTOMAKE, $AUTOHEADER, $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
+      --clean)
+         clean=1;;
 
-touch Makefile.am configure.ac
-{
-   LT=${LIBTOOLIZE-libtoolize}
-   echo "running $LT" >&2
-   $LT --force --copy --automake
-} && {
-   AL=${ACLOCAL-aclocal}
-   echo "running $AL" >&2
-   $AL
-} && {
-   AH=${AUTOHEADER-autoheader}
-   echo "running $AH [ignore the warnings]" >&2
-   $AH
-} && {
-   AM=${AUTOMAKE-automake}
-   echo "running $AM" >&2
-   $AM --force-missing --foreign -a -c
-} && {
-   AC=${AUTOCONF-autoconf}
-   echo "running $AC" >&2
-   $AC
-} &&
-   echo "autogen complete" >&2 ||
-   echo "ERROR: autogen.sh failed, autogen is incomplete" >&2
+      *)
+         exec >&2
+         echo "$0: usage: ./autogen.sh"
+         if test -d .git
+         then
+            echo "  ./autogen.sh generates the configure script and"
+            echo "  Makefile.in, or refreshes them after changes to Makefile.am"
+            echo "  or configure.ac.  You may prefer to just run autoreconf."
+         elif test -z "$maintainer"
+         then
+            echo "  DO NOT RUN THIS SCRIPT."
+            echo "  If you need to change Makefile.am or configure.ac then you"
+            echo "  also need to run ./configure --enable-maintainer-mode and"
+            echo "  use the appropriate autotools, *NOT* this script, to update"
+            echo "  everything, please check the documentation of autoreconf."
+            echo "  WARNING: libpng is intentionally generated with a known,"
+            echo "  fixed, set of autotools.  It is known *NOT* to work with"
+            echo "  the collection of autotools distributed on highly reputable"
+            echo "  operating systems."
+            echo "  Remember: autotools is GNU software, you are expected to"
+            echo "  pay for support."
+         else
+            echo "  You have run autogen.sh with --maintainer enabled and you"
+            echo "  are not using a GIT distribution, then you have given an"
+            echo "  unrecognized argument.  This is not good. --maintainer"
+            echo "  switches off any assumptions that you might not know what"
+            echo "  you are doing."
+         fi
+         exit 1;;
+   esac
+
+   shift
+done
+#
+# First check for a set of the autotools files; if absent then this is assumed
+# to be a GIT version and the local autotools must be used.  If present this
+# is a tarball distribution and the script should not be used.  If partially
+# present bad things are happening.
+#
+# The autotools generated files:
+libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in
+   config.h.in~ config.sub configure depcomp install-sh ltmain.sh missing\
+   test-driver"
+#
+# Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
+# versions than those required by configure.ac):
+libpng_autotools_extra="compile"
+#
+# These are separate because 'maintainer-clean' does not remove them.
+libpng_libtool_files="scripts/libtool.m4 scripts/ltoptions.m4\
+   scripts/ltsugar.m4 scripts/ltversion.m4 scripts/lt~obsolete.m4"
+
+libpng_autotools_dirs="autom4te.cache" # not required
+#
+# The configure generated files:
+libpng_configure_files="Makefile config.h config.log config.status\
+   libpng-config libpng.pc libtool stamp-h1"
+
+libpng_configure_dirs=".deps"
+#
+# We must remove the configure generated files as well as the autotools
+# generated files if autotools are regenerated because otherwise if configure
+# has been run without "--enable-maintainer-mode" make can do a partial update
+# of Makefile.  These functions do the two bits of cleaning.
+clean_autotools(){
+   rm -rf $libpng_autotools_files $libpng_libtool_files $libpng_autotools_dirs
+   rm -rf $libpng_autotools_extra
+}
+
+clean_configure(){
+   rm -rf $libpng_configure_files $libpng_configure_dirs
+}
+#
+# Clean: remove everything (this is to help with testing)
+if test -n "$clean"
+then
+   clean_configure
+   if test -n "$maintainer"
+   then
+      clean_autotools
+   fi
+
+   exit 0
+fi
+#
+# Validate the distribution.
+libpng_autotools_file_found=
+libpng_autotools_file_missing=
+for file in $libpng_autotools_files
+do
+   if test -f  "$file"
+   then
+      libpng_autotools_file_found=1
+   else
+      libpng_autotools_file_missing=1
+   fi
+done
+#
+# Presence of one of these does not *invalidate* missing, but absence
+# invalidates found.
+for file in $libpng_libtool_files
+do
+   if test ! -f "$file"
+   then
+      libpng_autotools_file_missing=1
+   fi
+done
+#
+# The cache directory doesn't matter - it will be regenerated and does not exist
+# anyway in a tarball.
+#
+# Either everything is missing or everything is there, the --maintainer option
+# just changes this so that the mode is set to generate all the files.
+mode=
+if test -z "$libpng_autotools_file_found" -o -n "$maintainer"
+then
+   mode="autoreconf"
+else
+   if test -n "$libpng_autotools_file_missing"
+   then
+      mode="broken"
+   else
+      mode="configure"
+   fi
+fi
+#
+# So:
+case "$mode" in
+   autoreconf)
+      # Clean in case configure files exist
+      clean_configure
+      clean_autotools
+      # Everything must be initialized, so use --force
+      if autoreconf --warnings=all --force --install
+      then
+         missing=
+         for file in $libpng_autotools_files
+         do
+            test -f "$file" || missing=1
+         done
+         # ignore the cache directory
+         test -z "$missing" || {
+            exec >&2
+            echo "autoreconf was run, but did not produce all the expected"
+            echo "files.  It is likely that your autotools installation is"
+            echo "not compatible with that expected by libpng."
+            exit 1
+         }
+      else
+         exec >&2
+         echo "autoreconf failed: your version of autotools is incompatible"
+         echo "with this libpng version.  Please use a distributed archive"
+         echo "(which includes the autotools generated files) and run configure"
+         echo "instead."
+         exit 1
+      fi;;
+
+   configure)
+      if test -d .git
+      then
+         exec >&2
+         echo "ERROR: running autoreconf on an initialized sytem"
+         echo "  This is not necessary; it is only necessary to remake the"
+         echo "  autotools generated files if Makefile.am or configure.ac"
+         echo "  change and make does the right thing with:"
+         echo
+         echo "     ./configure --enable-maintainer-mode."
+         echo
+         echo "  You can run autoreconf yourself if you don't like maintainer"
+         echo "  mode and you can also just run autoreconf -f -i to initialize"
+         echo "  everything in the first place; this script is only for"
+         echo "  compatibility with prior releases."
+         exit 1
+      else
+         exec >&2
+         echo "autogen.sh is intended only to generate 'configure' on systems"
+         echo "that do not have it.  You have a complete 'configure', if you"
+         echo "need to change Makefile.am or configure.ac you also need to"
+         echo "run configure with the --enable-maintainer-mode option."
+         exit 1
+      fi;;
+
+   broken)
+      exec >&2
+      echo "Your system has a partial set of autotools generated files."
+      echo "autogen.sh is unable to proceed.  The full set of files is"
+      echo "contained in the libpng 'tar' distribution archive and you do"
+      echo "not need to run autogen.sh if you use it."
+      exit 1;;
+esac

configure.ac

@@ -14,63 +14,101 @@ dnl Makefile.am to upgrade the package name.
 dnl This is here to prevent earlier autoconf from being used, it
 dnl should not be necessary to regenerate configure if the time
 dnl stamps are correct
-AC_PREREQ(2.59)
+AC_PREREQ([2.68])
 
 dnl Version number stuff here:
 
-AC_INIT([libpng], [1.6.0beta04], [png-mng-implement@lists.sourceforge.net])
-AM_INIT_AUTOMAKE
-dnl stop configure from automagically running automake
+AC_INIT([libpng],[1.6.18rc03],[png-mng-implement@lists.sourceforge.net])
+AC_CONFIG_MACRO_DIR([scripts])
+
+# libpng does not follow GNU file name conventions (hence 'foreign')
+# color-tests requires automake 1.11 or later
+# silent-rules requires automake 1.11 or later
+# dist-xz requires automake 1.11 or later
+# 1.12.2 fixes a security issue in 1.11.2 and 1.12.1
+# 1.13 is required for parallel tests
+AM_INIT_AUTOMAKE([1.13 foreign dist-xz color-tests silent-rules subdir-objects])
+# The following line causes --disable-maintainer-mode to be the default to
+# configure, this is necessary because libpng distributions cannot rely on the
+# time stamps of the autotools generated files being correct
 AM_MAINTAINER_MODE
 
-PNGLIB_VERSION=1.6.0beta04
+dnl configure.ac and Makefile.am expect automake 1.11.2 or a compatible later
+dnl version; aclocal.m4 will generate a failure if you use a prior version of
+dnl automake, so the following is not necessary (and is not defined anyway):
+dnl AM_PREREQ([1.11.2])
+dnl stop configure from automagically running automake
+
+PNGLIB_VERSION=1.6.18rc03
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=0
+PNGLIB_RELEASE=18
 
 dnl End of version number stuff
 
 AC_CONFIG_SRCDIR([pngget.c])
-AM_CONFIG_HEADER(config.h)
+AC_CONFIG_HEADERS([config.h])
 
 # Checks for programs.
 AC_LANG([C])
 AC_PROG_CC
 AM_PROG_AS
-AC_PROG_LD
+LT_PATH_LD
 AC_PROG_CPP
-AC_CHECK_TOOL(SED, sed, :)
-AC_CHECK_TOOL(AWK, awk, :)
+AC_PROG_AWK
 AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
-LT_INIT([win32-dll])
 
-# On Solaris 10 and 12 CPP gets set to cc -E, however this still
-# does some input parsing.  We need strict ANSI-C style tokenization,
-# check this:
-AC_REQUIRE_CPP
-AC_MSG_CHECKING([for a C preprocessor that does not parse its input])
-AC_TRY_CPP([1.5.0 16BIT],
-   [DFNCPP="$CPP"],
-   [DFNCPP=""
-   sav_CPP="$CPP"
-   for CPP in "${CC-cc} -E" "${CC-cc} -E -traditional-cpp" "/lib/cpp" "cpp"; do
-      AC_TRY_CPP([1.5.0 16BIT],
-         [DFNCPP="$CPP"]
-         [break],,)
-   done
-   CPP="$sav_CPP"])
-if test -n "$DFNCPP"; then
-   AC_MSG_RESULT([$DFNCPP])
-   AC_SUBST(DFNCPP)
+dnl libtool/libtoolize; version 2.4.2 is the tested version, this or any
+dnl compatible later version may be used
+LT_INIT([win32-dll])
+LT_PREREQ([2.4.2])
+
+# Some awks crash when confronted with pnglibconf.dfa, do a test run now
+# to make sure this doesn't happen
+AC_MSG_CHECKING([that AWK works])
+if ${AWK} -f ${srcdir}/scripts/options.awk out="/dev/null" version=search\
+   ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
+   ${srcdir}/pngusr.dfa 1>&2
+then
+   AC_MSG_RESULT([ok])
 else
-   AC_MSG_FAILURE([not found], 1)
+   AC_MSG_FAILURE([failed], 1)
 fi
 
+# This is a remnant of the old cc -E validation, where it may have been
+# necessary to use a different preprocessor for .dfn files
+DFNCPP="$CPP"
+AC_SUBST(DFNCPP)
+
+# -Werror cannot be passed to GCC in CFLAGS because configure will fail (it
+# checks the compiler with a program that generates a warning), add the
+# following option to deal with this
+AC_ARG_VAR(PNG_COPTS,
+   [additional flags for the C compiler, use this for options that would]
+   [cause configure itself to fail])
+AC_ARG_ENABLE(werror,
+   AS_HELP_STRING([[[--enable-werror[=OPT]]]],
+      [Pass -Werror or the given argument to the compiler if it is supported]),
+   [test "$enable_werror" = "yes" && enable_werror="-Werror"
+    if test "$enable_werror" != "no"; then
+      sav_CFLAGS="$CFLAGS"
+      CFLAGS="$enable_werror $CFLAGS"
+      AC_MSG_CHECKING([if the compiler allows $enable_werror])
+      AC_COMPILE_IFELSE(
+         [AC_LANG_SOURCE([
+            [int main(int argc, char **argv){]
+            [return argv[argc-1][0];]
+            [}]])],
+         AC_MSG_RESULT(yes)
+         PNG_COPTS="$PNG_COPTS $enable_werror",
+         AC_MSG_RESULT(no))
+      CFLAGS="$sav_CFLAGS"
+    fi],)
+
 # Checks for header files.
 AC_HEADER_STDC
-AC_CHECK_HEADERS([malloc.h stdlib.h string.h strings.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
@@ -80,16 +118,15 @@ AC_C_RESTRICT
 
 # Checks for library functions.
 AC_FUNC_STRTOD
-AC_CHECK_FUNCS([memset], , AC_ERROR([memset not found in libc]))
-AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_ERROR([cannot find pow])) )
+AC_CHECK_FUNCS([memset], , AC_MSG_ERROR(memset not found in libc))
+AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_MSG_ERROR(cannot find pow)) )
 AC_ARG_WITH(zlib-prefix,
-   AC_HELP_STRING([--with-zlib-prefix],
-                  [prefix that may have been used in installed zlib]),
-                  [ZPREFIX=${withval}],
-                  [ZPREFIX='z_'])
+   AS_HELP_STRING([[[--with-zlib-prefix]]],
+      [prefix that may have been used in installed zlib]),
+      [ZPREFIX=${withval}],
+      [ZPREFIX='z_'])
 AC_CHECK_LIB(z, zlibVersion, ,
-    AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, ,
-                 AC_ERROR([zlib not installed])))
+    AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, , AC_MSG_ERROR(zlib not installed)))
 
 # The following is for pngvalid, to ensure it catches FP errors even on
 # platforms that don't enable FP exceptions, the function appears in the math
@@ -141,9 +178,9 @@ 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 \
-                   | ${EGREP-grep} "^PREFIX=" \
-                   | ${SED-sed} "s:^PREFIX=::"`
+                  | ${CPP-${CC-gcc} -E} - 2>&1 \
+                  | ${EGREP-grep} "^PREFIX=" \
+                  | ${SED-sed} -e "s:^PREFIX=::" -e "s:__USER_LABEL_PREFIX__::"`
     AC_SUBST(SYMBOL_PREFIX)
     AC_MSG_RESULT($SYMBOL_PREFIX)
 fi
@@ -157,44 +194,131 @@ AC_SUBST(PNGLIB_RELEASE)
 # Additional arguments (and substitutions)
 # Allow the pkg-config directory to be set
 AC_ARG_WITH(pkgconfigdir,
-	AC_HELP_STRING([--with-pkgconfigdir],
-	[Use the specified pkgconfig dir (default is libdir/pkgconfig)]),
-	[pkgconfigdir=${withval}],
-	[pkgconfigdir='${libdir}/pkgconfig'])
+   AS_HELP_STRING([[[--with-pkgconfigdir]]],
+      [Use the specified pkgconfig dir (default is libdir/pkgconfig)]),
+   [pkgconfigdir=${withval}],
+   [pkgconfigdir='${libdir}/pkgconfig'])
 
 AC_SUBST([pkgconfigdir])
-AC_MSG_NOTICE([pkgconfig directory is ${pkgconfigdir}])
+AC_MSG_NOTICE([[pkgconfig directory is ${pkgconfigdir}]])
 
 # Make the *-config binary config scripts optional
 AC_ARG_WITH(binconfigs,
-	AC_HELP_STRING([--with-binconfigs],
-		[Generate shell libpng-config scripts as well as pkg-config data]
-		[@<:@default=yes@:>@]),
-	[if test "${withval}" = no; then
-		binconfigs=
-		AC_MSG_NOTICE([libpng-config scripts will not be built])
-	else
-		binconfigs='${binconfigs}'
-	fi],
-	[binconfigs='${binconfigs}'])
+   AS_HELP_STRING([[[--with-binconfigs]]],
+      [Generate shell libpng-config scripts as well as pkg-config data]
+      [@<:@default=yes@:>@]),
+   [if test "${withval}" = no; then
+      binconfigs=
+      AC_MSG_NOTICE([[libpng-config scripts will not be built]])
+    else
+      binconfigs='${binconfigs}'
+    fi],
+   [binconfigs='${binconfigs}'])
 AC_SUBST([binconfigs])
 
-# Because GCC by default assembles code with an executable stack, even though it
-# compiles C code with a non-executable stack, it is necessary to do a fixup
-# here (this may by GCC specific)
-AC_SUBST([AM_CCASFLAGS], [-Wa,--noexecstack])
+# Support for prefixes to the API function names; this will generate defines
+# at the start of the build to rename exported library functions
+AC_ARG_WITH(libpng-prefix,
+   AS_HELP_STRING([[[--with-libpng-prefix]]],
+      [prefix libpng exported function (API) names with the given value]),
+   [if test "${withval:-no}" != "no"; then
+      AC_SUBST([PNG_PREFIX], [${withval}])
+    fi])
+AM_CONDITIONAL([DO_PNG_PREFIX], [test "${with_libpng_prefix:-no}" != "no"])
+
+# Control over what links are made for installed files.  Versioned files are
+# always installed, when the following options are turned on corresponding
+# unversioned links are also created (normally as symbolic links):
+AC_ARG_ENABLE([unversioned-links],
+   AS_HELP_STRING([[[--enable-unversioned-links]]],
+      [Installed libpng header files are placed in a versioned subdirectory]
+      [and installed libpng library (including DLL) files are versioned.]
+      [If this option is enabled unversioned links will be created pointing to]
+      [the corresponding installed files.  If you use libpng.pc or]
+      [libpng-config for all builds you do not need these links, but if you]
+      [compile programs directly they will typically #include <png.h> and]
+      [link with -lpng; in that case you need the links.]
+      [The links can be installed manually using 'make install-header-links']
+      [and 'make install-library-links' and can be removed using the]
+      [corresponding uninstall- targets.  If you do enable this option every]
+      [libpng 'make install' will recreate the links to point to the just]
+      [installed version of libpng.  The default is to create the links;]
+      [use --disable-unversioned-links to change this]))
+
+# The AM_CONDITIONAL test is written so that the default is enabled;
+# --disable-unversioned-links must be given to turn the option off.
+AM_CONDITIONAL([DO_INSTALL_LINKS],[test "$enable_unversioned_links" != "no"])
+
+AC_ARG_ENABLE([unversioned-libpng-pc],
+   AS_HELP_STRING([[[--enable-unversioned-libpng-pc]]],
+      [Install the configuration file 'libpng.pc' as a link to the versioned]
+      [version.  This is done by default - use --disable-unversioned-libpng-pc]
+      [to change this.]))
+AM_CONDITIONAL([DO_INSTALL_LIBPNG_PC],
+   [test "$enable_unversioned_libpng_pc" != "no"])
+
+AC_ARG_ENABLE([unversioned-libpng-config],
+   AS_HELP_STRING([[[--enable-unversioned-libpng-config]]],
+      [Install the configuration file 'libpng-config' as a link to the]
+      [versioned version.  This is done by default - use]
+      [--disable-unversioned-libpng-config to change this.]))
+AM_CONDITIONAL([DO_INSTALL_LIBPNG_CONFIG],
+   [test "$enable_unversioned_libpng_config" != "no"])
+
+# HOST SPECIFIC OPTIONS
+# =====================
+#
+# ARM
+# ===
+#
+# ARM NEON (SIMD) support.
 
 AC_ARG_ENABLE([arm-neon],
-	AC_HELP_STRING([--enable-arm-neon], [Enable ARM NEON optimizations]),
-	[if test "${enableval}" = yes; then
-		AC_DEFINE([PNG_ARM_NEON], [1], [Enable ARM NEON optimizations])
-		AC_DEFINE([PNG_ALIGNED_MEMORY_SUPPORTED], [1], [Align row buffers])
-	fi])
-AM_CONDITIONAL([PNG_ARM_NEON], [test "${enable_arm_neon:-no}" = yes])
+   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])
+
+AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]])
 
 # Config files, substituting as above
 AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in])
 AC_CONFIG_FILES([libpng-config:libpng-config.in],
-		[chmod +x libpng-config])
+   [chmod +x libpng-config])
 
 AC_OUTPUT

contrib/arm-neon/README

@@ -0,0 +1,83 @@
+OPERATING SYSTEM SPECIFIC ARM NEON DETECTION
+--------------------------------------------
+
+Detection of the ability to execute ARM NEON on an ARM 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 arm/arm_init.c
+by setting the macro PNG_ARM_NEON_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 ARM NEON code must be enabled and run time
+checks must be supported.  I.e.:
+
+#if PNG_ARM_NEON_OPT > 0
+#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
+
+This is done in a 'configure' build by passing configure the argument:
+
+   --enable-arm-neon=check
+
+Apart from the basic Linux implementation in contrib/arm-neon/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_neon(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/arm-neon/android-ndk.c

@@ -0,0 +1,39 @@
+/* contrib/arm-neon/android-ndk.c
+ *
+ * Copyright (c) 2014 Glenn Randers-Pehrson
+ * Written by John Bowler, 2014.
+ * Last changed in libpng 1.6.10 [March 6, 2014]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * SEE contrib/arm-neon/README before reporting bugs
+ *
+ * STATUS: COMPILED, UNTESTED
+ * BUG REPORTS: png-mng-implement@sourceforge.net
+ *
+ * png_have_neon implemented for the Android NDK, see:
+ *
+ * Documentation:
+ *    http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
+ *    http://code.google.com/p/android/issues/detail?id=49065
+ *
+ * NOTE: this requires that libpng is built against the Android NDK and linked
+ * with an implementation of the Android ARM 'cpu-features' library.  The code
+ * has been compiled only, not linked: no version of the library has been found,
+ * only the header files exist in the NDK.
+ */
+#include <cpu-features.h>
+
+static int
+png_have_neon(png_structp png_ptr)
+{
+   /* This is a whole lot easier than the linux code, however it is probably
+    * implemented as below, therefore it is better to cache the result (these
+    * function calls may be slow!)
+    */
+   PNG_UNUSED(png_ptr)
+   return android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
+      (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
+}

contrib/arm-neon/linux-auxv.c

@@ -0,0 +1,120 @@
+/* contrib/arm-neon/linux-auxv.c
+ *
+ * Copyright (c) 2014 Glenn Randers-Pehrson
+ * Written by Mans Rullgard, 2011.
+ * Last changed in libpng 1.6.10 [March 6, 2014]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ * 
+ * SEE contrib/arm-neon/README before reporting bugs
+ *
+ * STATUS: COMPILED, TESTED
+ * BUG REPORTS: png-mng-implement@sourceforge.net
+ *
+ * png_have_neon implemented for Linux versions which allow access to
+ * /proc/self/auxv.  This is probably faster, cleaner and safer than the code to
+ * read /proc/cpuinfo in contrib/arm-neon/linux, however it is yet another piece
+ * of potentially untested code and has more complex dependencies than the code
+ * to read cpuinfo.
+ *
+ * This generic __linux__ implementation requires reading /proc/self/auxv and
+ * looking at each element for one that records NEON capabilities.
+ */
+#include <unistd.h> /* for POSIX 1003.1 */
+#include <errno.h>  /* for EINTR */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <elf.h>
+#include <asm/hwcap.h>
+
+/* A read call may be interrupted, in which case it returns -1 and sets errno to
+ * EINTR if nothing was done, otherwise (if something was done) a partial read
+ * may result.
+ */
+static size_t
+safe_read(png_structp png_ptr, int fd, void *buffer_in, size_t nbytes)
+{
+   size_t ntotal = 0;
+   char *buffer = png_voidcast(char*, buffer_in);
+
+   while (nbytes > 0)
+   {
+      unsigned int nread;
+      int iread;
+
+      /* Passing nread > INT_MAX to read is implementation defined in POSIX
+       * 1003.1, therefore despite the unsigned argument portable code must
+       * limit the value to INT_MAX!
+       */
+      if (nbytes > INT_MAX)
+         nread = INT_MAX;
+
+      else
+         nread = (unsigned int)/*SAFE*/nbytes;
+
+      iread = read(fd, buffer, nread);
+
+      if (iread == -1)
+      {
+         /* This is the devil in the details, a read can terminate early with 0
+          * bytes read because of EINTR, yet it still returns -1 otherwise end
+          * of file cannot be distinguished.
+          */
+         if (errno != EINTR)
+         {
+            png_warning(png_ptr, "/proc read failed");
+            return 0; /* I.e., a permanent failure */
+         }
+      }
+
+      else if (iread < 0)
+      {
+         /* Not a valid 'read' result: */
+         png_warning(png_ptr, "OS /proc read bug");
+         return 0;
+      }
+
+      else if (iread > 0)
+      {
+         /* Continue reading until a permanent failure, or EOF */
+         buffer += iread;
+         nbytes -= (unsigned int)/*SAFE*/iread;
+         ntotal += (unsigned int)/*SAFE*/iread;
+      }
+
+      else
+         return ntotal;
+   }
+
+   return ntotal; /* nbytes == 0 */
+}
+
+static int
+png_have_neon(png_structp png_ptr)
+{
+   int fd = open("/proc/self/auxv", O_RDONLY);
+   Elf32_auxv_t aux;
+
+   /* Failsafe: failure to open means no NEON */
+   if (fd == -1)
+   {
+      png_warning(png_ptr, "/proc/self/auxv open failed");
+      return 0;
+   }
+
+   while (safe_read(png_ptr, fd, &aux, sizeof aux) == sizeof aux)
+   {
+      if (aux.a_type == AT_HWCAP && (aux.a_un.a_val & HWCAP_NEON) != 0)
+      {
+         close(fd);
+         return 1;
+      }
+   }
+
+   close(fd);
+   return 0;
+}

contrib/arm-neon/linux.c

@@ -0,0 +1,161 @@
+/* contrib/arm-neon/linux.c
+ *
+ * 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
+ * and license in png.h
+ *
+ * SEE contrib/arm-neon/README before reporting bugs
+ *
+ * STATUS: SUPPORTED
+ * BUG REPORTS: png-mng-implement@sourceforge.net
+ *
+ * png_have_neon 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>
+
+static int
+png_have_neon(png_structp png_ptr)
+{
+   FILE *f = fopen("/proc/cpuinfo", "rb");
+
+   if (f != NULL)
+   {
+      /* This is a simple state machine which reads the input byte-by-byte until
+       * it gets a match on the 'neon' feature or reaches the end of the stream.
+       */
+      static const char ch_feature[] = { 70, 69, 65, 84, 85, 82, 69, 83 };
+      static const char ch_neon[] = { 78, 69, 79, 78 };
+
+      enum
+      {
+         StartLine, Feature, Colon, StartTag, Neon, HaveNeon, SkipTag, SkipLine
+      }  state;
+      int counter;
+
+      for (state=StartLine, counter=0;;)
+      {
+         int ch = fgetc(f);
+
+         if (ch == EOF)
+         {
+            /* EOF means error or end-of-file, return false; neon at EOF is
+             * assumed to be a mistake.
+             */
+            fclose(f);
+            return 0;
+         }
+
+         switch (state)
+         {
+            case StartLine:
+               /* Match spaces at the start of line */
+               if (ch <= 32) /* skip control characters and space */
+                  break;
+
+               counter=0;
+               state = Feature;
+               /* FALL THROUGH */
+
+            case Feature:
+               /* Match 'FEATURE', ASCII case insensitive. */
+               if ((ch & ~0x20) == ch_feature[counter])
+               {
+                  if (++counter == (sizeof ch_feature))
+                     state = Colon;
+                  break;
+               }
+               
+               /* did not match 'feature' */
+               state = SkipLine;
+               /* FALL THROUGH */
+
+            case SkipLine:
+            skipLine:
+               /* Skip everything until we see linefeed or carriage return */
+               if (ch != 10 && ch != 13)
+                  break;
+
+               state = StartLine;
+               break;
+
+            case Colon:
+               /* Match any number of space or tab followed by ':' */
+               if (ch == 32 || ch == 9)
+                  break;
+
+               if (ch == 58) /* i.e. ':' */
+               {
+                  state = StartTag;
+                  break;
+               }
+
+               /* Either a bad line format or a 'feature' prefix followed by
+                * other characters.
+                */
+               state = SkipLine;
+               goto skipLine;
+
+            case StartTag:
+               /* Skip space characters before a tag */
+               if (ch == 32 || ch == 9)
+                  break;
+
+               state = Neon;
+               counter = 0;
+               /* FALL THROUGH */
+
+            case Neon:
+               /* Look for 'neon' tag */
+               if ((ch & ~0x20) == ch_neon[counter])
+               {
+                  if (++counter == (sizeof ch_neon))
+                     state = HaveNeon;
+                  break;
+               }
+
+               state = SkipTag;
+               /* FALL THROUGH */
+
+            case SkipTag:
+               /* Skip non-space characters */
+               if (ch == 10 || ch == 13)
+                  state = StartLine;
+
+               else if (ch == 32 || ch == 9)
+                  state = StartTag;
+               break;
+
+            case HaveNeon:
+               /* Have seen a 'neon' prefix, but there must be a space or new
+                * line character to terminate it.
+                */
+               if (ch == 10 || ch == 13 || ch == 32 || ch == 9)
+               {
+                  fclose(f);
+                  return 1;
+               }
+
+               state = SkipTag;
+               break;
+
+            default:
+               png_error(png_ptr, "png_have_neon: internal error (bug)");
+         }
+      }
+   }
+
+#ifdef PNG_WARNINGS_SUPPORTED
+   else
+      png_warning(png_ptr, "/proc/cpuinfo open failed");
+#endif
+
+   return 0;
+}

contrib/conftest/README

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

contrib/conftest/read.dfa

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

contrib/conftest/s_read.dfa

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

contrib/conftest/s_write.dfa

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

contrib/conftest/simple.dfa

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

contrib/conftest/write.dfa

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

contrib/examples/iccfrompng.c

@@ -6,9 +6,9 @@
  * United States.
  *
  * Extract any icc profiles found in the given PNG files.  This is a simple
- * example of a program which extracts information from the header of a PNG file
+ * example of a program that extracts information from the header of a PNG file
  * without processing the image.  Notice that some header information may occur
- * after the image data, textual data and comments are an example; the approach
+ * after the image data. Textual data and comments are an example; the approach
  * in this file won't work reliably for such data because it only looks for the
  * information in the section of the file that preceeds the image data.
  *
@@ -26,6 +26,10 @@
 
 #include <png.h>
 
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) && \
+    defined (PNG_iCCP_SUPPORTED)
+
+
 static int verbose = 1;
 static png_byte no_profile[] = "no profile";
 
@@ -178,3 +182,4 @@ main(int argc, char **argv)
    /* Exit code is true if any extract succeeds */
    return extracted == 0;
 }
+#endif /* READ && STDIO && iCCP */

contrib/examples/pngpixel.c

@@ -8,7 +8,7 @@
  * Read a single pixel value from a PNG file.
  *
  * This code illustrates basic 'by-row' reading of a PNG file using libpng.
- * Rows are read until a particular pixel is found, the value of this pixel is
+ * Rows are read until a particular pixel is found; the value of this pixel is
  * then printed on stdout.
  *
  * The code illustrates how to do this on interlaced as well as non-interlaced
@@ -27,6 +27,8 @@
  */
 #include "../../png.h"
 
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_SEQUENTIAL_READ_SUPPORTED)
+
 /* Return component 'c' of pixel 'x' from the given row. */
 static unsigned int
 component(png_const_bytep row, png_uint_32 x, unsigned int c,
@@ -37,7 +39,7 @@ component(png_const_bytep row, png_uint_32 x, unsigned int c,
     * bytes wide.  Since the row fitted into memory, however, the following must
     * work:
     */
-   png_uint_32 bit_offset_hi = bit_depth * ((x >> 6) * channels + c);
+   png_uint_32 bit_offset_hi = bit_depth * ((x >> 6) * channels);
    png_uint_32 bit_offset_lo = bit_depth * ((x & 0x3f) * channels + c);
 
    row = (png_const_bytep)(((PNG_CONST png_byte (*)[8])row) + bit_offset_hi);
@@ -56,7 +58,7 @@ component(png_const_bytep row, png_uint_32 x, unsigned int c,
       case 8: return row[0];
       case 16: return (row[0] << 8) + row[1];
       default:
-         /* This should never happen, it indicates a bug in this program or in
+         /* This should never happen; it indicates a bug in this program or in
           * libpng itself:
           */
          fprintf(stderr, "pngpixel: invalid bit depth %u\n", bit_depth);
@@ -103,7 +105,7 @@ print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
                      index < num_trans ? trans_alpha[index] : 255);
 
                else /* no transparency */
-                  printf("INDEXED %u = %d %d %d\n", index, 
+                  printf("INDEXED %u = %d %d %d\n", index,
                      palette[index].red, palette[index].green,
                      palette[index].blue);
             }
@@ -132,7 +134,7 @@ print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
          return;
 
       default:
-         png_error(png_ptr, "invalid color type");
+         png_error(png_ptr, "pngpixel: invalid color type");
    }
 }
 
@@ -273,7 +275,7 @@ int main(int argc, const char **argv)
                            ystep = xstep = 1;
                         }
 
-                        /* To find the pixel loop over 'py' for each pass
+                        /* To find the pixel, loop over 'py' for each pass
                          * reading a row and then checking to see if it
                          * contains the pixel.
                          */
@@ -283,12 +285,13 @@ int main(int argc, const char **argv)
 
                            /* png_read_row takes two pointers.  When libpng
                             * handles the interlace the first is filled in
-                            * pixel-by-pixel, the second receives the same
+                            * pixel-by-pixel, and the second receives the same
                             * pixels but they are replicated across the
                             * unwritten pixels so far for each pass.  When we
                             * do the interlace, however, they just contain
                             * the pixels from the interlace pass - giving
-                            * both is wasteful and pointless.
+                            * both is wasteful and pointless, so we pass a
+                            * NULL pointer.
                             */
                            png_read_row(png_ptr, row_tmp, NULL);
 
@@ -326,7 +329,7 @@ int main(int argc, const char **argv)
                else
                {
                   /* Else libpng has raised an error.  An error message has
-                   * already been output, it is only necessary to clean up
+                   * already been output, so it is only necessary to clean up
                    * locally allocated data:
                    */
                   if (row != NULL)
@@ -365,3 +368,4 @@ int main(int argc, const char **argv)
 
    return result;
 }
+#endif /* READ && SEQUENTIAL_READ */

contrib/examples/pngtopng.c

@@ -20,6 +20,8 @@
  * ensure the code picks up the local libpng implementation:
  */
 #include "../../png.h"
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) && \
+    defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
 
 int main(int argc, const char **argv)
 {
@@ -29,13 +31,17 @@ int main(int argc, const char **argv)
    {
       png_image image;
 
+      /* Only the image structure version number needs to be set. */
       memset(&image, 0, sizeof image);
+      image.version = PNG_IMAGE_VERSION;
 
       if (png_image_begin_read_from_file(&image, argv[1]))
       {
          png_bytep buffer;
-         
-         /* Change this to try different formats! */
+
+         /* Change this to try different formats!  If you set a colormap format
+          * then you must also supply a colormap below.
+          */
          image.format = PNG_FORMAT_RGBA;
 
          buffer = malloc(PNG_IMAGE_SIZE(image));
@@ -43,10 +49,11 @@ int main(int argc, const char **argv)
          if (buffer != NULL)
          {
             if (png_image_finish_read(&image, NULL/*background*/, buffer,
-               0/*row_stride*/))
+               0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */))
             {
                if (png_image_write_to_file(&image, argv[2],
-                  0/*convert_to_8bit*/, buffer, 0/*row_stride*/))
+                  0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
+                  NULL/*colormap*/))
                   result = 0;
 
                else
@@ -85,3 +92,4 @@ int main(int argc, const char **argv)
 
    return result;
 }
+#endif /* READ && WRITE */

contrib/examples/simpleover.c

@@ -0,0 +1,648 @@
+/*- simpleover
+ *
+ * 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.
+ *
+ * Read several PNG files, which should have an alpha channel or transparency
+ * information, and composite them together to produce one or more 16-bit linear
+ * RGBA intermediates.  This involves doing the correct 'over' composition to
+ * combine the alpha channels and corresponding data.
+ *
+ * Finally read an output (background) PNG using the 24-bit RGB format (the
+ * PNG will be composited on green (#00ff00) by default if it has an alpha
+ * channel), and apply the intermediate image generated above to specified
+ * locations in the image.
+ *
+ * The command line has the general format:
+ *
+ *    simpleover <background.png> [output.png]
+ *        {--sprite=width,height,name {[--at=x,y] {sprite.png}}}
+ *        {--add=name {x,y}}
+ *
+ * The --sprite and --add options may occur multiple times. They are executed
+ * in order.  --add may refer to any sprite already read.
+ *
+ * This code is intended to show how to composite multiple images together
+ * correctly.  Apart from the libpng Simplified API the only work done in here
+ * is to combine multiple input PNG images into a single sprite; this involves
+ * a Porter-Duff 'over' operation and the input PNG images may, as a result,
+ * be regarded as being layered one on top of the other with the first (leftmost
+ * on the command line) being at the bottom and the last on the top.
+ */
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+
+/* Normally use <png.h> here to get the installed libpng, but this is done to
+ * ensure the code picks up the local libpng implementation, so long as this
+ * file is linked against a sufficiently recent libpng (1.6+) it is ok to
+ * change this to <png.h>:
+ */
+#include "../../png.h"
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+
+#define sprite_name_chars 15
+struct sprite {
+   FILE         *file;
+   png_uint_16p  buffer;
+   unsigned int  width;
+   unsigned int  height;
+   char          name[sprite_name_chars+1];
+};
+
+#if 0 /* div by 65535 test program */
+#include <math.h>
+#include <stdio.h>
+
+int main(void) {
+   double err = 0;
+   unsigned int xerr = 0;
+   unsigned int r = 32769;
+   {
+      unsigned int x = 0;
+
+      do {
+         unsigned int t = x + (x >> 16) /*+ (x >> 31)*/ + r;
+         double v = x, errtest;
+
+         if (t < x) {
+            fprintf(stderr, "overflow: %u+%u -> %u\n", x, r, t);
+            return 1;
+         }
+
+         v /= 65535;
+         errtest = v;
+         t >>= 16;
+         errtest -= t;
+
+         if (errtest > err) {
+            err = errtest;
+            xerr = x;
+
+            if (errtest >= .5) {
+               fprintf(stderr, "error: %u/65535 = %f, not %u, error %f\n",
+                     x, v, t, errtest);
+               return 0;
+            }
+         }
+      } while (++x <= 65535U*65535U);
+   }
+
+   printf("error %f @ %u\n", err, xerr);
+
+   return 0;
+}
+#endif /* div by 65535 test program */
+
+static void
+sprite_op(const struct sprite *sprite, int x_offset, int y_offset,
+   png_imagep image, const png_uint_16 *buffer)
+{
+   /* This is where the Porter-Duff 'Over' operator is evaluated; change this
+    * code to change the operator (this could be parameterized).  Any other
+    * image processing operation could be used here.
+    */
+
+
+   /* Check for an x or y offset that pushes any part of the image beyond the
+    * right or bottom of the sprite:
+    */
+   if ((y_offset < 0 || (unsigned)/*SAFE*/y_offset < sprite->height) &&
+       (x_offset < 0 || (unsigned)/*SAFE*/x_offset < sprite->width))
+   {
+      unsigned int y = 0;
+
+      if (y_offset < 0)
+         y = -y_offset; /* Skip to first visible row */
+
+      do
+      {
+         unsigned int x = 0;
+
+         if (x_offset < 0)
+            x = -x_offset;
+
+         do
+         {
+            /* In and out are RGBA values, so: */
+            const png_uint_16 *in_pixel = buffer + (y * image->width + x)*4;
+            png_uint_32 in_alpha = in_pixel[3];
+
+            /* This is the optimized Porter-Duff 'Over' operation, when the
+             * input alpha is 0 the output is not changed.
+             */
+            if (in_alpha > 0) 
+            {
+               png_uint_16 *out_pixel = sprite->buffer +
+                  ((y+y_offset) * sprite->width + (x+x_offset))*4;
+
+               /* This is the weight to apply to the output: */
+               in_alpha = 65535-in_alpha;
+
+               if (in_alpha > 0)
+               {
+                  /* The input must be composed onto the output. This means
+                   * multiplying the current output pixel value by the inverse
+                   * of the input alpha (1-alpha). A division is required but
+                   * it is by the constant 65535.  Approximate this as:
+                   *
+                   *     (x + (x >> 16) + 32769) >> 16;
+                   *
+                   * This is exact (and does not overflow) for all values of
+                   * x in the range 0..65535*65535.  (Note that the calculation
+                   * produces the closest integer; the maximum error is <0.5).
+                   */
+                  png_uint_32 tmp;
+
+#                 define compose(c)\
+                     tmp = out_pixel[c] * in_alpha;\
+                     tmp = (tmp + (tmp >> 16) + 32769) >> 16;\
+                     out_pixel[c] = tmp + in_pixel[c]
+
+                  /* The following is very vectorizable... */
+                  compose(0);
+                  compose(1);
+                  compose(2);
+                  compose(3);
+               }
+
+               else
+                  out_pixel[0] = in_pixel[0],
+                  out_pixel[1] = in_pixel[1],
+                  out_pixel[2] = in_pixel[2],
+                  out_pixel[3] = in_pixel[3];
+            }
+         }
+         while (++x < image->width);
+      }
+      while (++y < image->height);
+   }
+}
+
+static int 
+create_sprite(struct sprite *sprite, int *argc, const char ***argv)
+{
+   /* Read the arguments and create this sprite. The sprite buffer has already
+    * been allocated. This reads the input PNGs one by one in linear format,
+    * composes them onto the sprite buffer (the code in the function above)
+    * then saves the result, converting it on the fly to PNG RGBA 8-bit format.
+    */
+   while (*argc > 0)
+   {
+      char tombstone;
+      int x = 0, y = 0;
+
+      if ((*argv)[0][0] == '-' && (*argv)[0][1] == '-')
+      {
+         /* The only supported option is --at. */
+         if (sscanf((*argv)[0], "--at=%d,%d%c", &x, &y, &tombstone) != 2)
+            break; /* success; caller will parse this option */
+
+         ++*argv, --*argc;
+      }
+
+      else
+      {
+         /* The argument has to be a file name */
+         png_image image;
+
+         image.version = PNG_IMAGE_VERSION;
+         image.opaque = NULL;
+
+         if (png_image_begin_read_from_file(&image, (*argv)[0]))
+         {
+            png_uint_16p buffer;
+
+            image.format = PNG_FORMAT_LINEAR_RGB_ALPHA;
+
+            buffer = malloc(PNG_IMAGE_SIZE(image));
+
+            if (buffer != NULL)
+            {
+               if (png_image_finish_read(&image, NULL/*background*/, buffer,
+                  0/*row_stride*/,
+                  NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP*/))
+               {
+                  /* This is the place where the Porter-Duff 'Over' operator
+                   * needs to be done by this code.  In fact, any image
+                   * processing required can be done here; the data is in
+                   * the correct format (linear, 16-bit) and source and
+                   * destination are in memory.
+                   */
+                  sprite_op(sprite, x, y, &image, buffer);
+                  free(buffer);
+                  ++*argv, --*argc;
+                  /* And continue to the next argument */
+                  continue;
+               }
+
+               else
+               {
+                  free(buffer);
+                  fprintf(stderr, "simpleover: read %s: %s\n", (*argv)[0],
+                      image.message);
+               }
+            }
+
+            else
+            {
+               fprintf(stderr, "simpleover: out of memory: %lu bytes\n",
+                  (unsigned long)PNG_IMAGE_SIZE(image));
+
+               /* png_image_free must be called if we abort the Simplified API
+                * read because of a problem detected in this code.  If problems
+                * are detected in the Simplified API it cleans up itself.
+                */
+               png_image_free(&image);
+            }
+         }
+
+         else
+         {
+            /* Failed to read the first argument: */
+            fprintf(stderr, "simpleover: %s: %s\n", (*argv)[0], image.message);
+         }
+
+         return 0; /* failure */
+      }
+   }
+
+   /* All the sprite operations have completed successfully. Save the RGBA
+    * buffer as a PNG using the simplified write API.
+    */
+   sprite->file = tmpfile();
+
+   if (sprite->file != NULL)
+   {
+      png_image save;
+
+      memset(&save, 0, sizeof save);
+      save.version = PNG_IMAGE_VERSION;
+      save.opaque = NULL;
+      save.width = sprite->width;
+      save.height = sprite->height;
+      save.format = PNG_FORMAT_LINEAR_RGB_ALPHA;
+      save.flags = PNG_IMAGE_FLAG_FAST;
+      save.colormap_entries = 0;
+
+      if (png_image_write_to_stdio(&save, sprite->file, 1/*convert_to_8_bit*/,
+          sprite->buffer, 0/*row_stride*/, NULL/*colormap*/))
+      {
+         /* Success; the buffer is no longer needed: */
+         free(sprite->buffer);
+         sprite->buffer = NULL;
+         return 1; /* ok */
+      }
+
+      else
+         fprintf(stderr, "simpleover: write sprite %s: %s\n", sprite->name,
+            save.message);
+   }
+
+   else
+      fprintf(stderr, "simpleover: sprite %s: could not allocate tmpfile: %s\n",
+         sprite->name, strerror(errno));
+
+   return 0; /* fail */
+}
+
+static int
+add_sprite(png_imagep output, png_bytep out_buf, struct sprite *sprite,
+   int *argc, const char ***argv)
+{
+   /* Given a --add argument naming this sprite, perform the operations listed
+    * in the following arguments.  The arguments are expected to have the form
+    * (x,y), which is just an offset at which to add the sprite to the
+    * output.
+    */
+   while (*argc > 0)
+   {
+      char tombstone;
+      int x, y;
+
+      if ((*argv)[0][0] == '-' && (*argv)[0][1] == '-')
+         return 1; /* success */
+
+      if (sscanf((*argv)[0], "%d,%d%c", &x, &y, &tombstone) == 2)
+      {
+         /* Now add the new image into the sprite data, but only if it
+          * will fit.
+          */
+         if (x < 0 || y < 0 ||
+             (unsigned)/*SAFE*/x >= output->width ||
+             (unsigned)/*SAFE*/y >= output->height ||
+             sprite->width > output->width-x ||
+             sprite->height > output->height-y)
+         {
+            fprintf(stderr, "simpleover: sprite %s @ (%d,%d) outside image\n",
+               sprite->name, x, y);
+            /* Could just skip this, but for the moment it is an error */
+            return 0; /* error */
+         }
+
+         else
+         {
+            /* Since we know the sprite fits we can just read it into the
+             * output using the simplified API.
+             */
+            png_image in;
+
+            in.version = PNG_IMAGE_VERSION;
+            rewind(sprite->file);
+
+            if (png_image_begin_read_from_stdio(&in, sprite->file))
+            {
+               in.format = PNG_FORMAT_RGB; /* force compose */
+
+               if (png_image_finish_read(&in, NULL/*background*/,
+                  out_buf + (y*output->width + x)*3/*RGB*/,
+                  output->width*3/*row_stride*/,
+                  NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP*/))
+               {
+                  ++*argv, --*argc;
+                  continue;
+               }
+            }
+
+            /* The read failed: */
+            fprintf(stderr, "simpleover: add sprite %s: %s\n", sprite->name,
+                in.message);
+            return 0; /* error */
+         }
+      }
+
+      else
+      {
+         fprintf(stderr, "simpleover: --add='%s': invalid position %s\n",
+               sprite->name, (*argv)[0]);
+         return 0; /* error */
+      }
+   }
+
+   return 1; /* ok */
+}
+
+static int
+simpleover_process(png_imagep output, png_bytep out_buf, int argc,
+   const char **argv)
+{
+   int result = 1; /* success */
+#  define csprites 10/*limit*/
+#  define str(a) #a
+   int nsprites = 0;
+   struct sprite sprites[csprites];
+
+   while (argc > 0)
+   {
+      result = 0; /* fail */
+
+      if (strncmp(argv[0], "--sprite=", 9) == 0)
+      {
+         char tombstone;
+
+         if (nsprites < csprites)
+         {
+            int n;
+
+            sprites[nsprites].width = sprites[nsprites].height = 0;
+            sprites[nsprites].name[0] = 0;
+
+            n = sscanf(argv[0], "--sprite=%u,%u,%" str(sprite_name_chars) "s%c",
+                &sprites[nsprites].width, &sprites[nsprites].height,
+                sprites[nsprites].name, &tombstone);
+            
+            if ((n == 2 || n == 3) &&
+                sprites[nsprites].width > 0 && sprites[nsprites].height > 0)
+            {
+               size_t buf_size, tmp;
+
+               /* Default a name if not given. */
+               if (sprites[nsprites].name[0] == 0)
+                  sprintf(sprites[nsprites].name, "sprite-%d", nsprites+1);
+
+               /* Allocate a buffer for the sprite and calculate the buffer
+                * size:
+                */
+               buf_size = sizeof (png_uint_16 [4]);
+               buf_size *= sprites[nsprites].width;
+               buf_size *= sprites[nsprites].height;
+
+               /* This can overflow a (size_t); check for this: */
+               tmp = buf_size;
+               tmp /= sprites[nsprites].width;
+               tmp /= sprites[nsprites].height;
+
+               if (tmp == sizeof (png_uint_16 [4]))
+               {
+                  sprites[nsprites].buffer = malloc(buf_size);
+                  /* This buffer must be initialized to transparent: */
+                  memset(sprites[nsprites].buffer, 0, buf_size);
+
+                  if (sprites[nsprites].buffer != NULL)
+                  {
+                     sprites[nsprites].file = NULL;
+                     ++argv, --argc;
+
+                     if (create_sprite(sprites+nsprites++, &argc, &argv))
+                     {
+                        result = 1; /* still ok */
+                        continue;
+                     }
+
+                     break; /* error */
+                  }
+               }
+
+               /* Overflow, or OOM */
+               fprintf(stderr, "simpleover: %s: sprite too large\n", argv[0]);
+               break;
+            }
+
+            else
+            {
+               fprintf(stderr, "simpleover: %s: invalid sprite (%u,%u)\n",
+                  argv[0], sprites[nsprites].width, sprites[nsprites].height);
+               break;
+            }
+         }
+
+         else
+         {
+            fprintf(stderr, "simpleover: %s: too many sprites\n", argv[0]);
+            break;
+         }
+      }
+
+      else if (strncmp(argv[0], "--add=", 6) == 0)
+      {
+         const char *name = argv[0]+6;
+         int isprite = nsprites;
+
+         ++argv, --argc;
+
+         while (--isprite >= 0)
+         {
+            if (strcmp(sprites[isprite].name, name) == 0)
+            {
+               if (!add_sprite(output, out_buf, sprites+isprite, &argc, &argv))
+                  goto out; /* error in add_sprite */
+
+               break; 
+            }
+         }
+
+         if (isprite < 0) /* sprite not found */
+         {
+            fprintf(stderr, "simpleover: --add='%s': sprite not found\n", name);
+            break;
+         }
+      }
+
+      else
+      {
+         fprintf(stderr, "simpleover: %s: unrecognized operation\n", argv[0]);
+         break;
+      }
+
+      result = 1; /* ok  */
+   }
+
+   /* Clean up the cache of sprites: */
+out:
+   while (--nsprites >= 0)
+   {
+      if (sprites[nsprites].buffer != NULL)
+         free(sprites[nsprites].buffer);
+
+      if (sprites[nsprites].file != NULL)
+         (void)fclose(sprites[nsprites].file);
+   }
+
+   return result;
+}
+
+int main(int argc, const char **argv)
+{
+   int result = 1; /* default to fail */
+
+   if (argc >= 2)
+   {
+      int argi = 2;
+      const char *output = NULL;
+      png_image image;
+
+      if (argc > 2 && argv[2][0] != '-'/*an operation*/)
+      {
+         output = argv[2];
+         argi = 3;
+      }
+
+      image.version = PNG_IMAGE_VERSION;
+      image.opaque = NULL;
+
+      if (png_image_begin_read_from_file(&image, argv[1]))
+      {
+         png_bytep buffer;
+
+         image.format = PNG_FORMAT_RGB; /* 24-bit RGB */
+
+         buffer = malloc(PNG_IMAGE_SIZE(image));
+
+         if (buffer != NULL)
+         {
+            png_color background = {0, 0xff, 0}; /* fully saturated green */
+
+            if (png_image_finish_read(&image, &background, buffer,
+               0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */))
+            {
+               /* At this point png_image_finish_read has cleaned up the
+                * allocated data in png_image, and only the buffer needs to be
+                * freed.
+                *
+                * Perform the remaining operations:
+                */
+               if (simpleover_process(&image, buffer, argc-argi, argv+argi))
+               {
+                  /* Write the output: */
+                  if ((output != NULL &&
+                       png_image_write_to_file(&image, output,
+                        0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
+                        NULL/*colormap*/)) ||
+                      (output == NULL &&
+                       png_image_write_to_stdio(&image, stdout,
+                        0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
+                        NULL/*colormap*/)))
+                     result = 0;
+
+                  else
+                     fprintf(stderr, "simpleover: write %s: %s\n",
+                        output == NULL ? "stdout" : output, image.message);
+               }
+
+               /* else simpleover_process writes an error message */
+            }
+
+            else
+               fprintf(stderr, "simpleover: read %s: %s\n", argv[1],
+                   image.message);
+
+            free(buffer);
+         }
+
+         else
+         {
+            fprintf(stderr, "simpleover: out of memory: %lu bytes\n",
+               (unsigned long)PNG_IMAGE_SIZE(image));
+
+            /* This is the only place where a 'free' is required; libpng does
+             * the cleanup on error and success, but in this case we couldn't
+             * complete the read because of running out of memory.
+             */
+            png_image_free(&image);
+         }
+      }
+
+      else
+      {
+         /* Failed to read the first argument: */
+         fprintf(stderr, "simpleover: %s: %s\n", argv[1], image.message);
+      }
+   }
+
+   else
+   {
+      /* Usage message */
+      fprintf(stderr,
+         "simpleover: usage: simpleover background.png [output.png]\n"
+         "  Output 'background.png' as a 24-bit RGB PNG file in 'output.png'\n"
+         "   or, if not given, stdout.  'background.png' will be composited\n"
+         "   on fully saturated green.\n"
+         "\n"
+         "  Optionally, before output, process additional PNG files:\n"
+         "\n"
+         "   --sprite=width,height,name {[--at=x,y] {sprite.png}}\n"
+         "    Produce a transparent sprite of size (width,height) and with\n"
+         "     name 'name'.\n"
+         "    For each sprite.png composite it using a Porter-Duff 'Over'\n"
+         "     operation at offset (x,y) in the sprite (defaulting to (0,0)).\n"
+         "     Input PNGs will be truncated to the area of the sprite.\n"
+         "\n"
+         "   --add='name' {x,y}\n"
+         "    Optionally, before output, composite a sprite, 'name', which\n"
+         "     must have been previously produced using --sprite, at each\n"
+         "     offset (x,y) in the output image.  Each sprite must fit\n"
+         "     completely within the output image.\n"
+         "\n"
+         "  PNG files are processed in the order they occur on the command\n"
+         "  line and thus the first PNG processed appears as the bottommost\n"
+         "  in the output image.\n");
+   }
+
+   return result;
+}
+#endif /* SIMPLIFIED_READ */

contrib/gregbook/Makefile.mingw32

@@ -47,7 +47,8 @@ CC = gcc
 #CC = i386-mingw32msvc-gcc #	e.g., Linux -> Win32 cross-compilation
 LD = $(CC)
 RM = rm -f
-CFLAGS = -O -Wall $(INCS) $(MINGW_CCFLAGS)
+CPPFLAGS = $(INCS)
+CFLAGS = -O -Wall $(MINGW_CCFLAGS)
 # [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
 # [-ansi, -pedantic and -W can also be used]
 LDFLAGS = $(MINGW_LDFLAGS)
@@ -85,10 +86,10 @@ EXES = $(STATIC_EXES) $(DYNAMIC_EXES)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 %.pic$(O): %.c
-	$(CC) -c $(CFLAGS) -DPNG_BUILD_DLL -o $@ $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -DPNG_BUILD_DLL -o $@ $<
 
 
 # dependencies --------------------------------------------------------------

contrib/gregbook/Makefile.sgi

@@ -53,7 +53,8 @@ CC = cc
 LD = cc
 RM = rm -f
 # ABI must be the same as that used to build libpng.
-ABI=
+ABI =
+CPPFLAGS =
 CFLAGS = $(ABI) -O -fullwarn $(INCS)
 LDFLAGS = $(ABI)
 O = .o
@@ -73,7 +74,7 @@ EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 
 # dependencies --------------------------------------------------------------

contrib/gregbook/Makefile.unx

@@ -59,14 +59,16 @@ INCS = $(PNGINC) $(ZINC) $(XINC)
 RLIBSd = $(PNGLIBd) $(ZLIBd) $(XLIB) -lm
 RLIBSs = $(PNGLIBs) $(ZLIBs) $(XLIB) -lm
 WLIBSd = $(PNGLIBd) $(ZLIBd) -lm
-WLIBSs = $(PNGLIBs) $(ZLIBs)
+WLIBSs = $(PNGLIBs) $(ZLIBs) -lm
 
 CC = gcc
 LD = gcc
 RM = rm -f
-CFLAGS = -O -Wall $(INCS) -DFEATURE_LOOP
+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 and -W can also be used]
+# [-ansi, -pedantic, -Wextra, and -W can also be used]
 LDFLAGS =
 O = .o
 E =
@@ -92,7 +94,7 @@ EXES = $(STATIC_EXES) $(DYNAMIC_EXES)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 
 # dependencies --------------------------------------------------------------

contrib/gregbook/Makefile.w32

@@ -53,7 +53,8 @@ WLIBS = $(PNGLIB) $(ZLIB)
 CC = cl
 LD = link
 RM = del
-CFLAGS = -nologo -O -W3 $(INCS) $(cvars)
+CPPFLAGS = $(INCS)
+CFLAGS = -nologo -O -W3 $(cvars)
 # [note that -W3 is an MSVC-specific compilation flag ("all warnings on")]
 # [see %devstudio%\vc\include\win32.mak for cvars macro definition]
 O = .obj
@@ -76,7 +77,7 @@ EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 
 # dependencies --------------------------------------------------------------

contrib/gregbook/readpng.c

@@ -100,7 +100,8 @@ 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_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), NULL, NULL,
+        NULL);
     if (!png_ptr)
         return 4;   /* out of memory */
 
@@ -215,6 +216,10 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
      * libpng function */
 
     if (setjmp(png_jmpbuf(png_ptr))) {
+        free(image_data);
+        image_data = NULL;
+        free(row_pointers);
+        row_pointers = NULL;
         png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
         return NULL;
     }

contrib/gregbook/readpng2.c

@@ -69,6 +69,7 @@ static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
                                  png_uint_32 row_num, int pass);
 static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr);
 static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg);
+static void readpng2_warning_handler(png_structp png_ptr, png_const_charp msg);
 
 
 
@@ -103,8 +104,8 @@ int readpng2_init(mainprog_info *mainprog_ptr)
 
     /* could also replace libpng warning-handler (final NULL), but no need: */
 
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
-      readpng2_error_handler, NULL);
+    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), mainprog_ptr,
+      readpng2_error_handler, readpng2_warning_handler);
     if (!png_ptr)
         return 4;   /* out of memory */
 
@@ -136,29 +137,23 @@ int readpng2_init(mainprog_info *mainprog_ptr)
      * used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
      * IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
     {
-        /* These byte strings were copied from png.h.  If a future libpng
-         * version recognizes more chunks, add them to this list.  If a
-         * future version of readpng2.c recognizes more chunks, delete them
-         * from this list. */
-        static /* const */ png_byte chunks_to_ignore[] = {
-             99,  72,  82,  77, '\0',  /* cHRM */
-            104,  73,  83,  84, '\0',  /* hIST */
-            105,  67,  67,  80, '\0',  /* iCCP */
-            105,  84,  88, 116, '\0',  /* iTXt */
-            111,  70,  70, 115, '\0',  /* oFFs */
-            112,  67,  65,  76, '\0',  /* pCAL */
-            112,  72,  89, 115, '\0',  /* pHYs */
-            115,  66,  73,  84, '\0',  /* sBIT */
-            115,  67,  65,  76, '\0',  /* sCAL */
-            115,  80,  76,  84, '\0',  /* sPLT */
-            115,  84,  69,  82, '\0',  /* sTER */
-            116,  69,  88, 116, '\0',  /* tEXt */
-            116,  73,  77,  69, '\0',  /* tIME */
-            122,  84,  88, 116, '\0'   /* zTXt */
-        };
+        /* These byte strings were copied from png.h.  If a future version
+         * of readpng2.c recognizes more chunks, add them to this list.
+         */
+        static PNG_CONST png_byte chunks_to_process[] = {
+            98,  75,  71,  68, '\0',  /* bKGD */
+           103,  65,  77,  65, '\0',  /* gAMA */
+           115,  82,  71,  66, '\0',  /* sRGB */
+           };
 
-        png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
-          chunks_to_ignore, sizeof(chunks_to_ignore)/5);
+       /* Ignore all chunks except for IHDR, PLTE, tRNS, IDAT, and IEND */
+       png_set_keep_unknown_chunks(png_ptr, -1 /* PNG_HANDLE_CHUNK_NEVER */,
+          NULL, -1);
+
+       /* But do not ignore chunks in the "chunks_to_process" list */
+       png_set_keep_unknown_chunks(png_ptr,
+          0 /* PNG_HANDLE_CHUNK_AS_DEFAULT */, chunks_to_process,
+          sizeof(chunks_to_process)/5);
     }
 #endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */
 
@@ -453,6 +448,8 @@ static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr)
 
     /* all done */
 
+    (void)info_ptr; /* Unused */
+
     return;
 }
 
@@ -473,7 +470,12 @@ void readpng2_cleanup(mainprog_info *mainprog_ptr)
 }
 
 
-
+static void readpng2_warning_handler(png_structp png_ptr, png_const_charp msg)
+{
+    fprintf(stderr, "readpng2 libpng warning: %s\n", msg);
+    fflush(stderr);
+    (void)png_ptr; /* Unused */
+}
 
 
 static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)

contrib/gregbook/readppm.c

@@ -163,8 +163,12 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
 
     /* now we can go ahead and just read the whole image */
 
-    fread(image_data, 1L, rowbytes*height, saved_infile);
-
+    if (fread(image_data, 1L, rowbytes*height, saved_infile) <
+       rowbytes*height) {
+        free (image_data);
+        image_data = NULL;
+        return NULL;
+    }
 
     return image_data;
 }

contrib/gregbook/rpng-x.c

@@ -26,6 +26,8 @@
     - 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)
 
   ---------------------------------------------------------------------------
 
@@ -80,7 +82,7 @@
 
 #define PROGNAME  "rpng-x"
 #define LONGNAME  "Simple PNG Viewer for X"
-#define VERSION   "2.01 of 16 March 2008"
+#define VERSION   "2.02 of 15 June 2014"
 #define RESNAME   "rpng"        /* our X resource application name */
 #define RESCLASS  "Rpng"        /* our X resource class name */
 
@@ -279,15 +281,17 @@ 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"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n",
+          PROGNAME, default_display_exponent);
+
+        fprintf(stderr, "\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"
-          "\n", PROGNAME, default_display_exponent);
+          "is displayed) to quit.\n");
         exit(1);
     }
 
@@ -419,6 +423,8 @@ int main(int argc, char **argv)
 
     rpng_x_cleanup();
 
+    (void)argc; /* Unused */
+
     return 0;
 }
 

contrib/gregbook/rpng2-win.c

@@ -33,6 +33,8 @@
     - 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:  
+             (GR-P)
 
   ---------------------------------------------------------------------------
 

contrib/gregbook/rpng2-x.c

@@ -41,7 +41,11 @@
               unexpected-EOF and file-read-error cases; fixed Trace() cut-and-
               paste bugs
     - 2.03:  deleted runtime MMX-enabling/disabling and obsolete -mmx* options
+    - 2.04:  Added "void(foo);" statements to quiet pedantic compiler warnings
+             about unused variables (GR-P)
 
+  TO DO:
+             use nanosleep() instead of usleep(), which is obsolete/deprecated.
   ---------------------------------------------------------------------------
 
       Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
@@ -95,7 +99,7 @@
 
 #define PROGNAME  "rpng2-x"
 #define LONGNAME  "Progressive PNG Viewer for X"
-#define VERSION   "2.03 of 25 February 2010"
+#define VERSION   "2.04 of 15 June 2014"
 #define RESNAME   "rpng2"       /* our X resource application name */
 #define RESCLASS  "Rpng"       /* our X resource class name */
 
@@ -111,6 +115,18 @@
 #include <X11/Xos.h>
 #include <X11/keysym.h>   /* defines XK_* macros */
 
+#if _POSIX_C_SOURCE >= 199309L /* have nanosleep() */
+# undef usleep
+# define usleep(usec) {        \
+   struct timespec ts;         \
+   ts.tv_nsec = (usec) * 1000; \
+   nanosleep(&ts, NULL); }
+#  endif
+
+#ifndef usleep /* have neither nanosleep() nor usleep() */
+#  define usleep(x) sleep(((x)+499999)/1000000)
+#endif
+
 #ifdef VMS
 #  include <unistd.h>
 #endif
@@ -456,40 +472,47 @@ int main(int argc, char **argv)
         fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
         readpng2_version_info();
         fprintf(stderr, "\n"
-          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg | -bgpat pat]\n"
+          "Usage:   ");
+        fprintf(stderr,
+          "%s [-display xdpy] [-gamma exp] [-bgcolor bg | -bgpat pat]\n"
+          "        %*s [-usleep dur | -timing] [-pause]\n",
+          PROGNAME, (int)strlen(PROGNAME), " ");
+        fprintf(stderr,
 #ifdef FEATURE_LOOP
-          "        %*s [-usleep dur | -timing] [-pause] [-loop [sec]] file.png\n\n"
-#else
-          "        %*s [-usleep dur | -timing] [-pause] file.png\n\n"
+          "        [-loop [sec]]"
 #endif
+          " file.png\n\n");
+        fprintf(stderr,
           "    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"
-          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n",
+          default_display_exponent);
+        fprintf(stderr,
           "\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; overrides -bgpat\n"
           "    pat \tdesired background pattern number (0-%d); used with\n"
-          "\t\t  transparent images; overrides -bgcolor\n"
+          "\t\t  transparent images; overrides -bgcolor\n",
+          num_bgpat-1);
 #ifdef FEATURE_LOOP
+        fprintf(stderr, 
           "    -loop\tloops through background images after initial display\n"
           "\t\t  is complete (depends on -bgpat)\n"
-          "    sec \tseconds to display each background image (default = 2)\n"
+          "    sec \tseconds to display each background image (default = 2)\n");
 #endif
+        fprintf(stderr, 
           "    dur \tduration in microseconds to wait after displaying each\n"
           "\t\t  row (for demo purposes)\n"
           "    -timing\tenables delay for every block read, to simulate modem\n"
           "\t\t  download of image (~36 Kbps)\n"
           "    -pause\tpauses after displaying each pass until mouse clicked\n"
           "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
-          "is displayed) to quit.\n"
-          "\n", PROGNAME,
-          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat-1);
+          "is displayed) to quit.\n");
         exit(1);
     }
 
-
     if (!(infile = fopen(filename, "rb"))) {
         fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
         ++error;
@@ -735,6 +758,8 @@ int main(int argc, char **argv)
     Trace((stderr, "about to call rpng2_x_cleanup()\n"))
     rpng2_x_cleanup();
 
+    (void)argc; /* Unused */
+
     return 0;
 }
 
@@ -1826,6 +1851,9 @@ static void rpng2_x_redisplay_image(ulg startcol, ulg startrow,
         XFlush(display);
     }
 
+    (void)startcol;
+    (void)width;
+
 } /* end function rpng2_x_redisplay_image() */
 
 

contrib/gregbook/writepng.c

@@ -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_LIBPNG_VER_STRING, mainprog_ptr,
+    png_ptr = png_create_write_struct(png_get_libpng_ver(NULL), mainprog_ptr,
       writepng_error_handler, NULL);
     if (!png_ptr)
         return 4;   /* out of memory */

contrib/libtests/fakepng.c

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

contrib/libtests/gentests.sh

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

contrib/libtests/readpng.c

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

contrib/libtests/tarith.c

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

contrib/libtests/timepng.c

@@ -1,8 +1,8 @@
 /* timepng.c
  *
- * Copyright (c) 2011 John Cunningham Bowler
+ * Copyright (c) 2013 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.1 [March 28, 2013]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -22,7 +22,7 @@
 
 #include <time.h>
 
-#if (defined HAVE_CONFIG_H) && !(defined PNG_NO_CONFIG_H)
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
 #  include <config.h>
 #endif
 
@@ -252,7 +252,7 @@ int main(int argc, char **argv)
 
          while (fgets(filename, FILENAME_MAX+1, stdin))
          {
-            int len = strlen(filename);
+            size_t len = strlen(filename);
 
             if (filename[len-1] == '\n')
             {

contrib/pngminim/decoder/makefile

@@ -14,7 +14,8 @@ LD=$(CC)
 RM=rm -f
 COPY=cp
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. -O1
+CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -81,7 +82,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 
 # note: dependencies do not work on implicit rule lines
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 # dependencies
 
@@ -95,16 +96,16 @@ pngm2pnm$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) pngm2pnm$(O)
 	$(RM) pngm2pnm$(E)

contrib/pngminim/decoder/pngusr.dfa

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

contrib/pngminim/decoder/pngusr.h

@@ -1,6 +1,6 @@
 /* minrdpngconf.h: headers to make a minimal png-read-only library
  *
- * Copyright (c) 2007, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2007, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -18,7 +18,6 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
-#define PNG_NO_WARNINGS
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINRDPNGCONF_H */

contrib/pngminim/encoder/README

@@ -1,6 +1,6 @@
 This demonstrates the use of PNG_USER_CONFIG and pngusr.h
 
-The makefile builds a minimal write-only decoder with embedded libpng
+The makefile builds a minimal write-only encoder with embedded libpng
 and zlib.
 
 Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC

contrib/pngminim/encoder/makefile

@@ -14,7 +14,8 @@ LD=$(CC)
 RM=rm -f
 COPY=cp
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZIP -I. -O1
+CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -80,7 +81,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 # dependencies
 
@@ -94,16 +95,16 @@ pnm2pngm$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) pnm2pngm$(O)
 	$(RM) pnm2pngm$(E)

contrib/pngminim/encoder/pngusr.dfa

@@ -1,6 +1,6 @@
 # pngminim/encoder/pngusr.dfa
 #
-# Copyright (c) 2010-2011 Glenn Randers-Pehrson
+# Copyright (c) 2010-2013 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -14,6 +14,10 @@ everything = off
 
 option WRITE on
 
+# These 2 options are required if you need to read PBM (P1 or P4) files.
+option WRITE_INVERT on
+option WRITE_PACK on
+
 # You must choose fixed or floating point arithmetic:
 # option FLOATING_POINT on
 

contrib/pngminim/encoder/pngusr.h

@@ -1,6 +1,6 @@
 /* minwrpngconf.h: headers to make a minimal png-write-only library
  *
- * Copyright (c) 2007, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2007, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -18,7 +18,6 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
-#define PNG_NO_WARNINGS
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINWRPNGCONF_H */

contrib/pngminim/preader/makefile

@@ -30,7 +30,8 @@ XLIB = -L/usr/X11R6/lib -lX11
 #LIBS = $(XLIB)
 LIBS = $(XLIB) -lm                      #platforms that need libm
 
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP -I. $(XINC) -O1
+CPPFLAGS=-I. $(XINC) -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
 
 C=.c
 O=.o
@@ -96,7 +97,7 @@ OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
 # implicit make rules -------------------------------------------------------
 
 .c$(O):
-	$(CC) -c $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
 
 # dependencies
 
@@ -110,16 +111,16 @@ rpng2-x$(E): $(OBJS)
 # The CPP_FLAGS setting causes pngusr.h to be included in
 # both the build of pnglibconf.h and, subsequently, when
 # building libpng itself.
-$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak\
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
 	$(PNGSRC)/scripts/pnglibconf.dfa \
 	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
 	$(RM) pnglibconf.h pnglibconf.dfn
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
-	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG"\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
 	    DFA_XTRA="pngusr.dfa" $@
 
 clean:
-	$(MAKE) $(MAKEFLAGS) -f $(PNGSRC)/scripts/pnglibconf.mak\
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
 	    srcdir=$(PNGSRC) clean
 	$(RM) rpng2-x$(O)
 	$(RM) rpng2-x$(E)

contrib/pngminim/preader/pngusr.dfa

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

contrib/pngminim/preader/pngusr.h

@@ -1,6 +1,6 @@
 /* minrdpngconf.h: headers to make a minimal png-read-only library
  *
- * Copyright (c) 2009, 2010-2011 Glenn Randers-Pehrson
+ * Copyright (c) 2009, 2010-2013 Glenn Randers-Pehrson
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -18,7 +18,6 @@
  * affect the API (so are not recorded in pnglibconf.h)
  */
 
-#define PNG_NO_WARNINGS
 #define PNG_ALIGN_TYPE PNG_ALIGN_NONE
 
 #endif /* MINPRDPNGCONF_H */

contrib/pngminus/makefile.std

@@ -23,7 +23,8 @@ ZINC = -I../../../zlib
 ZLIB = -L../../../zlib -lz
 ZLIBS = ../../../zlib/libz.a
 
-CFLAGS=$(PNGINC) $(ZINC)
+CPPFLAGS=$(PNGINC) $(ZINC)
+CFLAGS=
 LDLIBS=$(PNGLIB) $(ZLIB)
 LDLIBSS=$(PNGLIBS) $(ZLIBS)
 C=.c
@@ -37,7 +38,7 @@ E=
 all: png2pnm$(E) pnm2png$(E) png2pnm-static$(E) pnm2png-static$(E)
 
 png2pnm$(O): png2pnm$(C)
-	$(CC) -c $(CFLAGS) png2pnm$(C)
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) png2pnm$(C)
 
 png2pnm$(E): png2pnm$(O)
 	$(LD) $(LDFLAGS) -o png2pnm$(E) png2pnm$(O) $(LDLIBS) -lm
@@ -46,7 +47,7 @@ png2pnm-static$(E): png2pnm$(O)
 	$(LD) $(LDFLAGS) -o png2pnm-static$(E) png2pnm$(O) $(LDLIBSS) -lm
 
 pnm2png$(O): pnm2png$(C)
-	$(CC) -c $(CFLAGS) pnm2png$(C)
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) pnm2png$(C)
 
 pnm2png$(E): pnm2png$(O)
 	$(LD) $(LDFLAGS) -o pnm2png$(E) pnm2png$(O) $(LDLIBS) -lm

contrib/pngminus/makefile.tc3

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

contrib/pngminus/png2pnm.c

@@ -52,7 +52,8 @@
 
 int  main (int argc, char *argv[]);
 void usage ();
-BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha);
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw,
+   BOOL alpha);
 
 /*
  *  main
@@ -85,7 +86,8 @@ int main(int argc, char *argv[])
           if ((fp_al = fopen (argv[argi], "wb")) == NULL)
           {
             fprintf (stderr, "PNM2PNG\n");
-            fprintf (stderr, "Error:  can not create alpha-channel file %s\n", argv[argi]);
+            fprintf (stderr, "Error:  can not create alpha-channel file %s\n",
+               argv[argi]);
             exit (1);
           }
           break;
@@ -176,9 +178,11 @@ void usage()
   fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
   fprintf (stderr, "   or:  ... | png2pnm [options]\n");
   fprintf (stderr, "Options:\n");
-  fprintf (stderr, "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
+  fprintf (stderr,
+     "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
   fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
-  fprintf (stderr, "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
+  fprintf (stderr,
+     "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
   fprintf (stderr, "   -h | -?  print this help-information\n");
 }
 
@@ -186,7 +190,8 @@ void usage()
  *  png2pnm
  */
 
-BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha)
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
+    volatile BOOL raw, BOOL alpha)
 {
   png_struct    *png_ptr = NULL;
   png_info        *info_ptr = NULL;
@@ -218,7 +223,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
 
   /* create png and info structures */
 
-  png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
+  png_ptr = png_create_read_struct (png_get_libpng_ver(NULL),
     NULL, NULL, NULL);
   if (!png_ptr)
     return FALSE;   /* out of memory */
@@ -315,12 +320,14 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
   /* row_bytes is the width x number of channels x (bit-depth / 8) */
   row_bytes = png_get_rowbytes (png_ptr, info_ptr);
 
-  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
+  if ((png_pixels = (png_byte *)
+     malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
     return FALSE;
   }
 
-  if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+  if ((row_pointers = (png_byte **)
+     malloc (height * sizeof (png_bytep))) == NULL)
   {
     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
     free (png_pixels);
@@ -329,7 +336,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
   }
 
   /* set the individual row_pointers to point at the correct offsets */
-  for (i = 0; i < (height); i++)
+  for (i = 0; i < ((int) height); i++)
     row_pointers[i] = png_pixels + i * row_bytes;
 
   /* now we can go ahead and just read the whole image */
@@ -372,9 +379,9 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
   /* write data to PNM file */
   pix_ptr = png_pixels;
 
-  for (row = 0; row < height; row++)
+  for (row = 0; row < (int) height; row++)
   {
-    for (col = 0; col < width; col++)
+    for (col = 0; col < (int) width; col++)
     {
       for (i = 0; i < (channels - alpha_present); i++)
       {

contrib/pngminus/pnm2png.c

@@ -50,7 +50,8 @@
 
 int  main (int argc, char *argv[]);
 void usage ();
-BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha);
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
+    BOOL alpha);
 void get_token(FILE *pnm_file, char *token);
 png_uint_32 get_data (FILE *pnm_file, int depth);
 png_uint_32 get_value (FILE *pnm_file, int depth);
@@ -176,7 +177,8 @@ void usage()
   fprintf (stderr, "   or:  ... | pnm2png [options]\n");
   fprintf (stderr, "Options:\n");
   fprintf (stderr, "   -i[nterlace]   write png-file with interlacing on\n");
-  fprintf (stderr, "   -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
+  fprintf (stderr,
+      "   -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
   fprintf (stderr, "   -h | -?  print this help-information\n");
 }
 
@@ -184,32 +186,36 @@ void usage()
  *  pnm2png
  */
 
-BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha)
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
+     BOOL alpha)
 {
   png_struct    *png_ptr = NULL;
   png_info      *info_ptr = NULL;
   png_byte      *png_pixels = NULL;
   png_byte      **row_pointers = NULL;
   png_byte      *pix_ptr = NULL;
-  png_uint_32   row_bytes;
+  volatile png_uint_32   row_bytes;
 
   char          type_token[16];
   char          width_token[16];
   char          height_token[16];
   char          maxval_token[16];
-  int           color_type;
-  unsigned long   ul_width, ul_alpha_width;
-  unsigned long   ul_height, ul_alpha_height;
-  unsigned long   ul_maxval;
-  png_uint_32   width, alpha_width;
-  png_uint_32   height, alpha_height;
+  volatile int           color_type;
+  unsigned long   ul_width=0, ul_alpha_width=0;
+  unsigned long   ul_height=0, ul_alpha_height=0;
+  unsigned long   ul_maxval=0;
+  volatile png_uint_32   width, height;
+  volatile png_uint_32   alpha_width, alpha_height;
   png_uint_32   maxval;
-  int           bit_depth = 0;
+  volatile int           bit_depth = 0;
   int           channels;
   int           alpha_depth = 0;
   int           alpha_present;
   int           row, col;
   BOOL          raw, alpha_raw = FALSE;
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  BOOL          packed_bitmap = FALSE;
+#endif
   png_uint_32   tmp16;
   int           i;
 
@@ -222,9 +228,21 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   }
   else if ((type_token[1] == '1') || (type_token[1] == '4'))
   {
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
     raw = (type_token[1] == '4');
     color_type = PNG_COLOR_TYPE_GRAY;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &ul_width);
+    width = (png_uint_32) ul_width;
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &ul_height);
+    height = (png_uint_32) ul_height;
     bit_depth = 1;
+    packed_bitmap = TRUE;
+#else
+    fprintf (stderr, "PNM2PNG built without PNG_WRITE_INVERT_SUPPORTED and \n");
+    fprintf (stderr, "PNG_WRITE_PACK_SUPPORTED can't read PBM (P1,P4) files\n");
+#endif
   }
   else if ((type_token[1] == '2') || (type_token[1] == '5'))
   {
@@ -239,7 +257,7 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
     get_token(pnm_file, maxval_token);
     sscanf (maxval_token, "%lu", &ul_maxval);
     maxval = (png_uint_32) ul_maxval;
-    
+
     if (maxval <= 1)
       bit_depth = 1;
     else if (maxval <= 3)
@@ -343,56 +361,72 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 
   alpha_present = (channels - 1) % 2;
 
-  /* row_bytes is the width x number of channels x (bit-depth / 8) */
-  row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  if (packed_bitmap)
+    /* row data is as many bytes as can fit width x channels x bit_depth */
+    row_bytes = (width * channels * bit_depth + 7) / 8;
+  else
+#endif
+    /* row_bytes is the width x number of channels x (bit-depth / 8) */
+    row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
 
-  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
+  if ((png_pixels = (png_byte *)
+     malloc (row_bytes * height * sizeof (png_byte))) == NULL)
     return FALSE;
 
   /* read data from PNM file */
   pix_ptr = png_pixels;
 
-  for (row = 0; row < height; row++)
+  for (row = 0; row < (int) height; row++)
   {
-    for (col = 0; col < width; col++)
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+    if (packed_bitmap) {
+      for (i = 0; i < (int) row_bytes; i++)
+        /* png supports this format natively so no conversion is needed */
+        *pix_ptr++ = get_data (pnm_file, 8);
+    } else
+#endif
     {
-      for (i = 0; i < (channels - alpha_present); i++)
+      for (col = 0; col < (int) width; col++)
       {
-        if (raw)
-          *pix_ptr++ = get_data (pnm_file, bit_depth);
-        else
-          if (bit_depth <= 8)
-            *pix_ptr++ = get_value (pnm_file, bit_depth);
+        for (i = 0; i < (channels - alpha_present); i++)
+        {
+          if (raw)
+            *pix_ptr++ = get_data (pnm_file, bit_depth);
           else
-          {
-            tmp16 = get_value (pnm_file, bit_depth);
-            *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
-            pix_ptr++;
-            *pix_ptr = (png_byte) (tmp16 & 0xFF);
-            pix_ptr++;
-          }
-      }
+            if (bit_depth <= 8)
+              *pix_ptr++ = get_value (pnm_file, bit_depth);
+            else
+            {
+              tmp16 = get_value (pnm_file, bit_depth);
+              *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
+              pix_ptr++;
+              *pix_ptr = (png_byte) (tmp16 & 0xFF);
+              pix_ptr++;
+            }
+        }
 
-      if (alpha) /* read alpha-channel from pgm file */
-      {
-        if (alpha_raw)
-          *pix_ptr++ = get_data (alpha_file, alpha_depth);
-        else
-          if (alpha_depth <= 8)
-            *pix_ptr++ = get_value (alpha_file, bit_depth);
+        if (alpha) /* read alpha-channel from pgm file */
+        {
+          if (alpha_raw)
+            *pix_ptr++ = get_data (alpha_file, alpha_depth);
           else
-          {
-            tmp16 = get_value (alpha_file, bit_depth);
-            *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
-            *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
-          }
-      } /* if alpha */
-
+            if (alpha_depth <= 8)
+              *pix_ptr++ = get_value (alpha_file, bit_depth);
+            else
+            {
+              tmp16 = get_value (alpha_file, bit_depth);
+              *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
+              *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
+            }
+        } /* if alpha */
+      } /* if packed_bitmap */
     } /* end for col */
   } /* end for row */
 
   /* prepare the standard PNG structures */
-  png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  png_ptr = png_create_write_struct (png_get_libpng_ver(NULL), NULL, NULL,
+      NULL);
   if (!png_ptr)
   {
     return FALSE;
@@ -404,6 +438,14 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
     return FALSE;
   }
 
+#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
+  if (packed_bitmap == TRUE)
+  {
+    png_set_packing (png_ptr);
+    png_set_invert_mono (png_ptr);
+  }
+#endif
+
   /* setjmp() must be called in every function that calls a PNG-reading libpng function */
   if (setjmp (png_jmpbuf(png_ptr)))
   {
@@ -425,7 +467,8 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   /* if needed we will allocate memory for an new array of row-pointers */
   if (row_pointers == (unsigned char**) NULL)
   {
-    if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+    if ((row_pointers = (png_byte **)
+        malloc (height * sizeof (png_bytep))) == NULL)
     {
       png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
       return FALSE;
@@ -433,13 +476,13 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
   }
 
   /* set the individual row_pointers to point at the correct offsets */
-  for (i = 0; i < (height); i++)
+  for (i = 0; i < (int) height; i++)
     row_pointers[i] = png_pixels + i * row_bytes;
 
   /* write out the entire image data in one call */
   png_write_image (png_ptr, row_pointers);
 
-  /* write the additional chuncks to the PNG file (not really needed) */
+  /* write the additional chunks to the PNG file (not really needed) */
   png_write_end (png_ptr, info_ptr);
 
   /* clean up after the write, and free any memory allocated */
@@ -460,19 +503,32 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
 void get_token(FILE *pnm_file, char *token)
 {
   int i = 0;
+  int ret;
 
-  /* remove white-space */
+  /* remove white-space and comment lines */
   do
   {
-    token[i] = (unsigned char) fgetc (pnm_file);
+    ret = fgetc(pnm_file);
+    if (ret == '#') {
+      /* the rest of this line is a comment */
+      do
+      {
+        ret = fgetc(pnm_file);
+      }
+      while ((ret != '\n') && (ret != '\r') && (ret != EOF));
+    }
+    if (ret == EOF) break;
+    token[i] = (unsigned char) ret;
   }
   while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
 
   /* read string */
   do
   {
+    ret = fgetc(pnm_file);
+    if (ret == EOF) break;
     i++;
-    token[i] = (unsigned char) fgetc (pnm_file);
+    token[i] = (unsigned char) ret;
   }
   while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
 
@@ -524,7 +580,7 @@ png_uint_32 get_value (FILE *pnm_file, int depth)
 {
   static png_uint_32 mask = 0;
   png_byte token[16];
-  unsigned long ulret_value;
+  unsigned long ul_ret_value;
   png_uint_32 ret_value;
   int i = 0;
 
@@ -533,8 +589,8 @@ png_uint_32 get_value (FILE *pnm_file, int depth)
       mask = (mask << 1) | 0x01;
 
   get_token (pnm_file, (char *) token);
-  sscanf ((const char *) token, "%lu", &ulret_value);
-  ret_value = (png_uint_32) ulret_value;
+  sscanf ((const char *) token, "%lu", &ul_ret_value);
+  ret_value = (png_uint_32) ul_ret_value;
 
   ret_value &= mask;
 

contrib/pngsuite/README

@@ -1,7 +1,8 @@
 
 pngsuite
 --------
-(c) Willem van Schaik, 1999, 2011
+(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.
@@ -38,6 +39,8 @@ can use them to test the proper functioning of PNG software.
     basn6a08.png   8-bit RGBA
     basn6a16.png  16-bit RGBA
 
+    ftbbn0g01.png  1-bit grayscale, black bKGD
+    ftbbn0g02.png  2-bit grayscale, black bKGD
     ftbbn0g04.png  4-bit grayscale, black bKGD
     ftbbn2c16.png 16-bit truecolor, black bKGD
     ftbbn3p08.png  8-bit paletted, black bKGD

contrib/tools/checksum-icc.c

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

contrib/tools/cvtcolor.c

@@ -1,9 +1,9 @@
 /*-
  * convert.c
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.0 [February 14, 2013]
  *
- * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * COPYRIGHT: Written by John Cunningham Bowler, 2013.
  * To the extent possible under law, the author has waived all copyright and
  * related or neighboring rights to this work.  This work is published from:
  * United States.

contrib/tools/genpng.c

@@ -0,0 +1,867 @@
+/*- genpng
+ *
+ * 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.
+ *
+ * Generate a PNG with an alpha channel, correctly.
+ *
+ * This is a test case generator; the resultant PNG files are only of interest
+ * to those of us who care about whether the edges of circles are green, red,
+ * or yellow.
+ *
+ * The program generates an RGB+Alpha PNG of a given size containing the given
+ * shapes on a transparent background:
+ *
+ *  genpng width height { shape }
+ *    shape ::= color width shape x1 y1 x2 y2
+ *
+ * 'color' is:
+ *
+ *  black white red green yellow blue brown purple pink orange gray cyan
+ *
+ * The point is to have colors that are linguistically meaningful plus that old
+ * bugbear of the department store dress murders, Cyan, the only color we argue
+ * about.
+ *
+ * 'shape' is:
+ *
+ *  circle: an ellipse
+ *  square: a rectangle
+ *  line: a straight line
+ *
+ * Each shape is followed by four numbers, these are two points in the output
+ * coordinate space (as real numbers) which describe the circle, square, or
+ * line.  The shape is filled if it is preceded by 'filled' (not valid for
+ * 'line') or is drawn with a line, in which case the width of the line must
+ * precede the shape.
+ *
+ * The whole set of information can be repeated as many times as desired:
+ *
+ *    shape ::= color width shape x1 y1 x2 y2
+ *
+ *    color ::= black|white|red|green|yellow|blue
+ *    color ::= brown|purple|pink|orange|gray|cyan
+ *    width ::= filled
+ *    width ::= <number>
+ *    shape ::= circle|square|line
+ *    x1    ::= <number>
+ *    x2    ::= <number>
+ *    y1    ::= <number>
+ *    y2    ::= <number>
+ *
+ * The output PNG is generated by down-sampling a 4x supersampled image using
+ * a bi-cubic filter.  The bi-cubic has a 2 (output) pixel width, so an 8x8
+ * array of super-sampled points contribute to each output pixel.  The value of
+ * a super-sampled point is found using an unfiltered, aliased, infinite
+ * precision image: Each shape from the last to the first is checked to see if
+ * the point is in the drawn area and, if it is, the color of the point is the
+ * color of the shape and the alpha is 1, if not the previous shape is checked.
+ *
+ * This is an aliased algorithm because no filtering is done; a point is either
+ * inside or outside each shape and 'close' points do not contribute to the
+ * sample.  The down-sampling is relied on to correct the error of not using
+ * a filter.
+ *
+ * The line end-caps are 'flat'; they go through the points.  The square line
+ * joins are mitres; the outside of the lines are continued to the point of
+ * intersection.
+ */
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <math.h>
+
+/* Normally use <png.h> here to get the installed libpng, but this is done to
+ * ensure the code picks up the local libpng implementation:
+ */
+#include "../../png.h"
+
+#if defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
+
+static const struct color
+{
+   const char *name;
+   double      red;
+   double      green;
+   double      blue;
+} colors[] =
+/* color ::= black|white|red|green|yellow|blue
+ * color ::= brown|purple|pink|orange|gray|cyan
+ */
+{
+   { "black",   0,    0,  0 },
+   { "white",   1,    1,  1 },
+   { "red",     1,    0,  0 },
+   { "green",   0,    1,  0 },
+   { "yellow",  1,    1,  0 },
+   { "blue",    0,    0,  1 },
+   { "brown",  .5, .125,  0 },
+   { "purple",  1,    0,  1 },
+   { "pink",    1,   .5, .5 },
+   { "orange",  1,   .5,  0 },
+   { "gray",    0,   .5, .5 },
+   { "cyan",    0,    1,  1 }
+};
+#define color_count ((sizeof colors)/(sizeof colors[0]))
+
+static const struct color *
+color_of(const char *arg)
+{
+   int icolor = color_count;
+
+   while (--icolor >= 0)
+   {
+      if (strcmp(colors[icolor].name, arg) == 0)
+         return colors+icolor;
+   }
+
+   fprintf(stderr, "genpng: invalid color %s\n", arg);
+   exit(1);
+}
+
+static double
+width_of(const char *arg)
+{
+   if (strcmp(arg, "filled") == 0)
+      return 0;
+
+   else
+   {
+      char *ep = NULL;
+      double w = strtod(arg, &ep);
+
+      if (ep != NULL && *ep == 0 && w > 0)
+         return w;
+   }
+
+   fprintf(stderr, "genpng: invalid line width %s\n", arg);
+   exit(1);
+}
+
+static double
+coordinate_of(const char *arg)
+{
+   char *ep = NULL;
+   double w = strtod(arg, &ep);
+
+   if (ep != NULL && *ep == 0)
+      return w;
+
+   fprintf(stderr, "genpng: invalid coordinate value %s\n", arg);
+   exit(1);
+}
+
+struct arg; /* forward declaration */
+
+typedef int (*shape_fn_ptr)(const struct arg *arg, double x, double y);
+   /* A function to determine if (x,y) is inside the shape.
+    *
+    * There are two implementations:
+    *
+    *    inside_fn: returns true if the point is inside
+    *    check_fn:  returns;
+    *       -1: the point is outside the shape by more than the filter width (2)
+    *        0: the point may be inside the shape
+    *       +1: the point is inside the shape by more than the filter width
+    */
+#define OUTSIDE (-1)
+#define INSIDE  (1)
+
+struct arg
+{
+   const struct color *color;
+   shape_fn_ptr        inside_fn;
+   shape_fn_ptr        check_fn;
+   double              width; /* line width, 0 for 'filled' */
+   double              x1, y1, x2, y2;
+};
+
+/* IMPLEMENTATION NOTE:
+ *
+ * We want the contribution of each shape to the sample corresponding to each
+ * pixel.  This could be obtained by super sampling the image to infinite
+ * dimensions, finding each point within the shape and assigning that a value
+ * '1' while leaving every point outside the shape with value '0' then
+ * downsampling to the image size with sinc; computationally very expensive.
+ *
+ * Approximations are as follows:
+ *
+ * 1) If the pixel coordinate is within the shape assume the sample has the
+ *    shape color and is opaque, else assume there is no contribution from
+ *    the shape.
+ *
+ *    This is the equivalent of aliased rendering or resampling an image with
+ *    a block filter.  The maximum error in the calculated alpha (which will
+ *    always be 0 or 1) is 0.5.
+ *
+ * 2) If the shape is within a square of size 1x1 centered on the pixel assume
+ *    that the shape obscures an amount of the pixel equal to its area within
+ *    that square.
+ *
+ *    This is the equivalent of 'pixel coverage' alpha calculation or resampling
+ *    an image with a bi-linear filter.  The maximum error is over 0.2, but the
+ *    results are often acceptable.
+ *
+ *    This can be approximated by applying (1) to a super-sampled image then
+ *    downsampling with a bi-linear filter.  The error in the super-sampled
+ *    image is 0.5 per sample, but the resampling reduces this.
+ *
+ * 3) Use a better filter with a super-sampled image; in the limit this is the
+ *    sinc() approach.
+ *
+ * 4) Do the geometric calculation; a bivariate definite integral across the
+ *    shape, unfortunately this means evaluating Si(x), the integral of sinc(x),
+ *    which is still a lot of math.
+ *
+ * This code uses approach (3) with a bi-cubic filter and 8x super-sampling
+ * and method (1) for the super-samples.  This means that the sample is either
+ * 0 or 1, depending on whether the sub-pixel is within or outside the shape.
+ * The bi-cubic weights are also fixed and the 16 required weights are
+ * pre-computed here (note that the 'scale' setting will need to be changed if
+ * 'super' is increased).
+ *
+ * The code also calculates a sum to the edge of the filter. This is not
+ * currently used by could be used to optimize the calculation.
+ */
+#if 0 /* bc code */
+scale=10
+super=8
+define bicubic(x) {
+   if (x <= 1) return (1.5*x - 2.5)*x*x + 1;
+   if (x <  2) return (((2.5 - 0.5*x)*x - 4)*x + 2);
+   return 0;
+}
+define sum(x) {
+   auto s;
+   s = 0;
+   while (x < 2*super) {
+      s = s + bicubic(x/super);
+      x = x + 1;
+   }
+   return s;
+}
+define results(x) {
+   auto b, s;
+   b = bicubic(x/super);
+   s = sum(x);
+
+   print "   /*", x, "*/ { ", b, ", ", s, " }";
+   return 1;
+}
+x=0
+while (x<2*super) {
+   x = x + results(x)
+   if (x < 2*super) print ","
+   print "\n"
+}
+quit
+#endif
+
+#define BICUBIC1(x) /*     |x| <= 1 */ ((1.5*(x)* - 2.5)*(x)*(x) + 1)
+#define BICUBIC2(x) /* 1 < |x| <  2 */ (((2.5 - 0.5*(x))*(x) - 4)*(x) + 2)
+#define FILTER_WEIGHT 9 /* Twice the first sum below */
+#define FILTER_WIDTH  2 /* Actually half the width; -2..+2 */
+#define FILTER_STEPS  8 /* steps per filter unit */
+static const double
+bicubic[16][2] =
+{
+   /* These numbers are exact; the weight for the filter is 1/9, but this
+    * would make the numbers inexact, so it is not included here.
+    */
+   /*          bicubic      sum        */
+   /* 0*/ { 1.0000000000, 4.5000000000 },
+   /* 1*/ {  .9638671875, 3.5000000000 },
+   /* 2*/ {  .8671875000, 2.5361328125 },
+   /* 3*/ {  .7275390625, 1.6689453125 },
+   /* 4*/ {  .5625000000,  .9414062500 },
+   /* 5*/ {  .3896484375,  .3789062500 },
+   /* 6*/ {  .2265625000, -.0107421875 },
+   /* 7*/ {  .0908203125, -.2373046875 },
+   /* 8*/ {            0, -.3281250000 },
+   /* 9*/ { -.0478515625, -.3281250000 },
+   /*10*/ { -.0703125000, -.2802734375 },
+   /*11*/ { -.0732421875, -.2099609375 },
+   /*12*/ { -.0625000000, -.1367187500 },
+   /*13*/ { -.0439453125, -.0742187500 },
+   /*14*/ { -.0234375000, -.0302734375 },
+   /*15*/ { -.0068359375, -.0068359375 }
+};
+
+static double
+alpha_calc(const struct arg *arg, double x, double y)
+{
+   /* For [x-2..x+2],[y-2,y+2] calculate the weighted bicubic given a function
+    * which tells us whether a point is inside or outside the shape.  First
+    * check if we need to do this at all:
+    */
+   switch (arg->check_fn(arg, x, y))
+   {
+      case OUTSIDE:
+         return 0; /* all samples outside the shape */
+
+      case INSIDE:
+         return 1; /* all samples inside the shape */
+
+      default:
+      {
+         int dy;
+         double alpha = 0;
+
+#        define FILTER_D (FILTER_WIDTH*FILTER_STEPS-1)
+         for (dy=-FILTER_D; dy<=FILTER_D; ++dy)
+         {
+            double wy = bicubic[abs(dy)][0];
+
+            if (wy != 0)
+            {
+               double alphay = 0;
+               int dx;
+
+               for (dx=-FILTER_D; dx<=FILTER_D; ++dx)
+               {
+                  double wx = bicubic[abs(dx)][0];
+
+                  if (wx != 0 && arg->inside_fn(arg, x+dx/16, y+dy/16)) 
+                     alphay += wx;
+               }
+
+               alpha += wy * alphay;
+            }
+         }
+
+         /* This needs to be weighted for each dimension: */
+         return alpha / (FILTER_WEIGHT*FILTER_WEIGHT);
+      }
+   }
+}
+
+/* These are the shape functions. */
+/* "square",
+ * { inside_square_filled, check_square_filled },
+ * { inside_square, check_square }
+ */
+static int
+square_check(double x, double y, double x1, double y1, double x2, double y2)
+   /* Is x,y inside the square (x1,y1)..(x2,y2)? */
+{
+   /* Do a modified Cohen-Sutherland on one point, bit patterns that indicate
+    * 'outside' are:
+    *
+    *   x<x1 | x<y1 | x<x2 | x<y2
+    *    0      x      0      x     To the right
+    *    1      x      1      x     To the left
+    *    x      0      x      0     Below
+    *    x      1      x      1     Above
+    *
+    * So 'inside' is (x<x1) != (x<x2) && (y<y1) != (y<y2);
+    */
+   return ((x<x1) ^ (x<x2)) & ((y<y1) ^ (y<y2));
+}
+
+static int
+inside_square_filled(const struct arg *arg, double x, double y)
+{
+   return square_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2);
+}
+
+static int
+square_check_line(const struct arg *arg, double x, double y, double w)
+   /* Check for a point being inside the boundaries implied by the given arg
+    * and assuming a width 2*w each side of the boundaries.  This returns the
+    * 'check' INSIDE/OUTSIDE/0 result but note the semantics:
+    *
+    *          +--------------+
+    *          |              |   OUTSIDE
+    *          |   INSIDE     |
+    *          |              |
+    *          +--------------+
+    *
+    * And '0' means within the line boundaries.
+    */
+{
+   double cx = (arg->x1+arg->x2)/2;
+   double wx = fabs(arg->x1-arg->x2)/2;
+   double cy = (arg->y1+arg->y2)/2;
+   double wy = fabs(arg->y1-arg->y2)/2;
+
+   if (square_check(x, y, cx-wx-w, cy-wy-w, cx+wx+w, cy+wy+w))
+   {
+      /* Inside, but maybe too far; check for the redundant case where
+       * the lines overlap:
+       */
+      wx -= w;
+      wy -= w;
+      if (wx > 0 && wy > 0 && square_check(x, y, cx-wx, cy-wy, cx+wx, cy+wy))
+         return INSIDE; /* between (inside) the boundary lines. */
+
+      return 0; /* inside the lines themselves. */
+   }
+
+   return OUTSIDE; /* outside the boundary lines. */
+}
+
+static int
+check_square_filled(const struct arg *arg, double x, double y)
+{
+   /* The filter extends +/-FILTER_WIDTH each side of each output point, so
+    * the check has to expand and contract the square by that amount; '0'
+    * means close enough to the edge of the square that the bicubic filter has
+    * to be run, OUTSIDE means alpha==0, INSIDE means alpha==1.
+    */
+   return square_check_line(arg, x, y, FILTER_WIDTH);
+}
+
+static int
+inside_square(const struct arg *arg, double x, double y)
+{
+   /* Return true if within the drawn lines, else false, no need to distinguish
+    * INSIDE vs OUTSIDE here:
+    */
+   return square_check_line(arg, x, y, arg->width/2) == 0;
+}
+
+static int
+check_square(const struct arg *arg, double x, double y)
+{
+   /* So for this function a result of 'INSIDE' means inside the actual lines.
+    */
+   double w = arg->width/2;
+
+   if (square_check_line(arg, x, y, w+FILTER_WIDTH) == 0)
+   {
+      /* Somewhere close to the boundary lines. If far enough inside one of
+       * them then we can return INSIDE:
+       */
+      w -= FILTER_WIDTH;
+
+      if (w > 0 && square_check_line(arg, x, y, w) == 0)
+         return INSIDE;
+
+      /* Point is somewhere in the filter region: */
+      return 0;
+   }
+
+   else /* Inside or outside the square by more than w+FILTER_WIDTH. */
+      return OUTSIDE;
+}
+
+/* "circle",
+ * { inside_circle_filled, check_circle_filled },
+ * { inside_circle, check_circle }
+ *
+ * The functions here are analoguous to the square ones; however, they check
+ * the corresponding ellipse as opposed to the rectangle.
+ */
+static int
+circle_check(double x, double y, double x1, double y1, double x2, double y2)
+{
+   if (square_check(x, y, x1, y1, x2, y2))
+   {
+      /* Inside the square, so maybe inside the circle too: */
+      const double cx = (x1 + x2)/2;
+      const double cy = (y1 + y2)/2;
+      const double dx = x1 - x2;
+      const double dy = y1 - y2;
+
+      x = (x - cx)/dx;
+      y = (y - cy)/dy;
+
+      /* It is outside if the distance from the center is more than half the
+       * diameter:
+       */
+      return x*x+y*y < .25;
+   }
+
+   return 0; /* outside */
+}
+
+static int
+inside_circle_filled(const struct arg *arg, double x, double y)
+{
+   return circle_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2);
+}
+
+static int
+circle_check_line(const struct arg *arg, double x, double y, double w)
+   /* Check for a point being inside the boundaries implied by the given arg
+    * and assuming a width 2*w each side of the boundaries.  This function has
+    * the same semantic as square_check_line but tests the circle.
+    */
+{
+   double cx = (arg->x1+arg->x2)/2;
+   double wx = fabs(arg->x1-arg->x2)/2;
+   double cy = (arg->y1+arg->y2)/2;
+   double wy = fabs(arg->y1-arg->y2)/2;
+
+   if (circle_check(x, y, cx-wx-w, cy-wy-w, cx+wx+w, cy+wy+w))
+   {
+      /* Inside, but maybe too far; check for the redundant case where
+       * the lines overlap:
+       */
+      wx -= w;
+      wy -= w;
+      if (wx > 0 && wy > 0 && circle_check(x, y, cx-wx, cy-wy, cx+wx, cy+wy))
+         return INSIDE; /* between (inside) the boundary lines. */
+
+      return 0; /* inside the lines themselves. */
+   }
+
+   return OUTSIDE; /* outside the boundary lines. */
+}
+
+static int
+check_circle_filled(const struct arg *arg, double x, double y)
+{
+   return circle_check_line(arg, x, y, FILTER_WIDTH);
+}
+
+static int
+inside_circle(const struct arg *arg, double x, double y)
+{
+   return circle_check_line(arg, x, y, arg->width/2) == 0;
+}
+
+static int
+check_circle(const struct arg *arg, double x, double y)
+{
+   /* Exactly as the 'square' code.  */
+   double w = arg->width/2;
+
+   if (circle_check_line(arg, x, y, w+FILTER_WIDTH) == 0)
+   {
+      w -= FILTER_WIDTH;
+
+      if (w > 0 && circle_check_line(arg, x, y, w) == 0)
+         return INSIDE;
+
+      /* Point is somewhere in the filter region: */
+      return 0;
+   }
+
+   else /* Inside or outside the square by more than w+FILTER_WIDTH. */
+      return OUTSIDE;
+}
+
+/* "line",
+ * { NULL, NULL },  There is no 'filled' line.
+ * { inside_line, check_line }
+ */
+static int
+line_check(double x, double y, double x1, double y1, double x2, double y2,
+   double w, double expand)
+{
+   /* Shift all the points to (arg->x1, arg->y1) */
+   double lx = x2 - x1;
+   double ly = y2 - y1;
+   double len2 = lx*lx + ly*ly;
+   double cross, dot;
+
+   x -= x1;
+   y -= y1;
+
+   /* The dot product is the distance down the line, the cross product is
+    * the distance away from the line:
+    *
+    *    distance = |cross| / sqrt(len2) 
+    */
+   cross = x * ly - y * lx;
+
+   /* If 'distance' is more than w the point is definitely outside the line:
+    *
+    *     distance >= w
+    *     |cross|  >= w * sqrt(len2)
+    *     cross^2  >= w^2 * len2:
+    */
+   if (cross*cross >= (w+expand)*(w+expand)*len2)
+      return 0; /* outside */
+
+   /* Now find the distance *along* the line; this comes from the dot product
+    * lx.x+ly.y. The actual distance (in pixels) is:
+    *
+    *   distance = dot / sqrt(len2)
+    */
+   dot = lx * x + ly * y;
+
+   /* The test for 'outside' is:
+    *
+    *    distance < 0 || distance > sqrt(len2)
+    *                 -> dot / sqrt(len2) > sqrt(len2)
+    *                 -> dot > len2
+    *
+    * But 'expand' is used for the filter width and needs to be handled too:
+    */
+   return dot > -expand && dot < len2+expand;
+}
+
+static int
+inside_line(const struct arg *arg, double x, double y)
+{
+   return line_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2, arg->width/2, 0);
+}
+
+static int
+check_line(const struct arg *arg, double x, double y)
+{
+   /* The end caps of the line must be checked too; it's not enough just to
+    * widen the line by FILTER_WIDTH; 'expand' exists for this purpose:
+    */
+   if (line_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2, arg->width/2,
+       FILTER_WIDTH))
+   {
+      /* Inside the line+filter; far enough inside that the filter isn't
+       * required?
+       */
+      if (arg->width > 2*FILTER_WIDTH &&
+          line_check(x, y, arg->x1, arg->y1, arg->x2, arg->y2, arg->width/2,
+             -FILTER_WIDTH))
+         return INSIDE;
+
+      return 0;
+   }
+
+   return OUTSIDE;
+}
+
+static const struct
+{
+   const char    *name;
+   shape_fn_ptr   function[2/*fill,line*/][2];
+#  define         FN_INSIDE 0
+#  define         FN_CHECK 1
+} shape_defs[] =
+{
+   {  "square",
+      {  { inside_square_filled, check_square_filled },
+         { inside_square, check_square } }
+   },
+   {  "circle",
+      {  { inside_circle_filled, check_circle_filled },
+         { inside_circle, check_circle } }
+   },
+   {  "line",
+      {  { NULL, NULL },
+         { inside_line, check_line } }
+   }
+};
+
+#define shape_count ((sizeof shape_defs)/(sizeof shape_defs[0]))
+
+static shape_fn_ptr
+shape_of(const char *arg, double width, int f)
+{
+   unsigned int i;
+
+   for (i=0; i<shape_count; ++i) if (strcmp(shape_defs[i].name, arg) == 0)
+   {
+      shape_fn_ptr fn = shape_defs[i].function[width != 0][f];
+
+      if (fn != NULL)
+         return fn;
+
+      fprintf(stderr, "genpng: %s %s not supported\n",
+         width == 0 ? "filled" : "unfilled", arg);
+      exit(1);
+   }
+
+   fprintf(stderr, "genpng: %s: not a valid shape name\n", arg);
+   exit(1);
+}
+
+static void
+parse_arg(struct arg *arg, const char **argv/*7 arguments*/)
+{
+   /* shape ::= color width shape x1 y1 x2 y2 */
+   arg->color = color_of(argv[0]);
+   arg->width = width_of(argv[1]);
+   arg->inside_fn = shape_of(argv[2], arg->width, FN_INSIDE);
+   arg->check_fn = shape_of(argv[2], arg->width, FN_CHECK);
+   arg->x1 = coordinate_of(argv[3]);
+   arg->y1 = coordinate_of(argv[4]);
+   arg->x2 = coordinate_of(argv[5]);
+   arg->y2 = coordinate_of(argv[6]);
+}
+
+static png_uint_32
+read_wh(const char *name, const char *str)
+   /* read a PNG width or height */
+{
+   char *ep = NULL;
+   unsigned long ul = strtoul(str, &ep, 10);
+
+   if (ep != NULL && *ep == 0 && ul > 0 && ul <= 0x7fffffff)
+      return (png_uint_32)/*SAFE*/ul;
+
+   fprintf(stderr, "genpng: %s: invalid number %s\n", name, str);
+   exit(1);
+}
+
+static void
+pixel(png_uint_16p p, struct arg *args, int nargs, double x, double y)
+{
+   /* Fill in the pixel by checking each shape (args[nargs]) for effects on
+    * the corresponding sample:
+    */
+   double r=0, g=0, b=0, a=0;
+
+   while (--nargs >= 0 && a != 1)
+   {
+      /* NOTE: alpha_calc can return a value outside the range 0..1 with the
+       * bicubic filter.
+       */
+      const double alpha = alpha_calc(args+nargs, x, y) * (1-a);
+
+      r += alpha * args[nargs].color->red;
+      g += alpha * args[nargs].color->green;
+      b += alpha * args[nargs].color->blue;
+      a += alpha;
+   }
+
+   /* 'a' may be negative or greater than 1; if it is, negative clamp the
+    * pixel to 0 if >1 clamp r/g/b:
+    */
+   if (a > 0) 
+   {
+      if (a > 1)
+      {
+         if (r > 1) r = 1;
+         if (g > 1) g = 1;
+         if (b > 1) b = 1;
+         a = 1;
+      }
+
+      /* And fill in the pixel: */
+      p[0] = (png_uint_16)/*SAFE*/round(r * 65535);
+      p[1] = (png_uint_16)/*SAFE*/round(g * 65535);
+      p[2] = (png_uint_16)/*SAFE*/round(b * 65535);
+      p[3] = (png_uint_16)/*SAFE*/round(a * 65535);
+   }
+
+   else
+      p[3] = p[2] = p[1] = p[0] = 0;
+}
+
+int
+main(int argc, const char **argv)
+{
+   int convert_to_8bit = 0;
+
+   /* There is one option: --8bit: */
+   if (argc > 1 && strcmp(argv[1], "--8bit") == 0)
+      --argc, ++argv, convert_to_8bit = 1;
+
+   if (argc >= 3)
+   {
+      png_uint_16p buffer;
+      int nshapes;
+      png_image image;
+#     define max_shapes 256
+      struct arg arg_list[max_shapes];
+
+      /* The libpng Simplified API write code requires a fully initialized
+       * structure.
+       */
+      memset(&image, 0, sizeof image);
+      image.version = PNG_IMAGE_VERSION;
+      image.opaque = NULL;
+      image.width = read_wh("width", argv[1]);
+      image.height = read_wh("height", argv[2]);
+      image.format = PNG_FORMAT_LINEAR_RGB_ALPHA;
+      image.flags = 0;
+      image.colormap_entries = 0;
+
+      /* Check the remainder of the arguments */
+      for (nshapes=0; 3+7*(nshapes+1) <= argc && nshapes < max_shapes;
+           ++nshapes)
+         parse_arg(arg_list+nshapes, argv+3+7*nshapes);
+
+      if (3+7*nshapes != argc)
+      {
+         fprintf(stderr, "genpng: %s: too many arguments\n", argv[3+7*nshapes]);
+         return 1;
+      }
+
+      /* Create the buffer: */
+      buffer = malloc(PNG_IMAGE_SIZE(image));
+
+      if (buffer != NULL)
+      {
+         png_uint_32 y;
+
+         /* Write each row... */
+         for (y=0; y<image.height; ++y)
+         {
+            png_uint_32 x;
+
+            /* Each pixel in each row: */
+            for (x=0; x<image.width; ++x)
+               pixel(buffer + 4*(x + y*image.width), arg_list, nshapes, x, y);
+         }
+
+         /* Write the result (to stdout) */
+         if (png_image_write_to_stdio(&image, stdout, convert_to_8bit,
+             buffer, 0/*row_stride*/, NULL/*colormap*/))
+         {
+            free(buffer);
+            return 0; /* success */
+         }
+
+         else
+            fprintf(stderr, "genpng: write stdout: %s\n", image.message);
+
+         free(buffer);
+      }
+
+      else
+         fprintf(stderr, "genpng: out of memory: %lu bytes\n",
+               (unsigned long)PNG_IMAGE_SIZE(image));
+   }
+
+   else
+   {
+      /* Wrong number of arguments */
+      fprintf(stderr, "genpng: usage: genpng [--8bit] width height {shape}\n"
+         " Generate a transparent PNG in RGBA (truecolor+alpha) format\n"
+         " containing the given shape or shapes.  Shapes are defined:\n"
+         "\n"
+         "  shape ::= color width shape x1 y1 x2 y2\n"
+         "  color ::= black|white|red|green|yellow|blue\n"
+         "  color ::= brown|purple|pink|orange|gray|cyan\n"
+         "  width ::= filled|<number>\n"
+         "  shape ::= circle|square|line\n"
+         "  x1,x2 ::= <number>\n"
+         "  y1,y2 ::= <number>\n"
+         "\n"
+         " Numbers are floating point numbers describing points relative to\n"
+         " the top left of the output PNG as pixel coordinates.  The 'width'\n"
+         " parameter is either the width of the line (in output pixels) used\n"
+         " to draw the shape or 'filled' to indicate that the shape should\n"
+         " be filled with the color.\n"
+         "\n"
+         " Colors are interpreted loosely to give access to the eight full\n"
+         " intensity RGB values:\n"
+         "\n"
+         "  black, red, green, blue, yellow, cyan, purple, white,\n"
+         "\n"
+         " Cyan is full intensity blue+green; RGB(0,1,1), plus the following\n"
+         " lower intensity values:\n"
+         "\n"
+         "  brown:  red+orange:  RGB(0.5, 0.125, 0) (dark red+orange)\n"
+         "  pink:   red+white:   RGB(1.0, 0.5,   0.5)\n"
+         "  orange: red+yellow:  RGB(1.0, 0.5,   0)\n"
+         "  gray:   black+white: RGB(0.5, 0.5,   0.5)\n"
+         "\n"
+         " The RGB values are selected to make detection of aliasing errors\n"
+         " easy. The names are selected to make the description of errors\n"
+         " easy.\n"
+         "\n"
+         " The PNG is written to stdout, if --8bit is given a 32bpp RGBA sRGB\n"
+         " file is produced, otherwise a 64bpp RGBA linear encoded file is\n"
+         " written.\n");
+   }
+
+   return 1;
+}
+#endif /* SIMPLIFIED_WRITE && STDIO */

contrib/tools/intgamma.sh

@@ -2,9 +2,9 @@
 #
 # intgamma.sh
 #
-# Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+# Last changed in libpng 1.6.0 [February 14, 2013]
 #
-# COPYRIGHT: Written by John Cunningham Bowler, 2011.
+# COPYRIGHT: Written by John Cunningham Bowler, 2013.
 # To the extent possible under law, the author has waived all copyright and
 # related or neighboring rights to this work.  This work is published from:
 # United States.

contrib/tools/makesRGB.c

@@ -1,8 +1,8 @@
 /* makesRGB.c -- build sRGB-to-linear and linear-to-sRGB conversion tables
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.0 [February 14, 2013]
  *
- * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * COPYRIGHT: Written by John Cunningham Bowler, 2013.
  * To the extent possible under law, the author has waived all copyright and
  * related or neighboring rights to this work.  This work is published from:
  * United States.

contrib/tools/png-fix-itxt.c

@@ -0,0 +1,164 @@
+
+/* png-fix-itxt version 1.0.0
+ *
+ * Copyright 2015 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.18 [(PENDING RELEASE)]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Usage:            
+ *
+ *     png-fix-itxt.exe < bad.png > good.png
+ *
+ * Fixes a PNG file written with libpng-1.6.0 or 1.6.1 that has one or more
+ * uncompressed iTXt chunks.  Assumes that the actual length is greater
+ * than or equal to the value in the length byte, and that the CRC is
+ * correct for the actual length.  This program hunts for the CRC and
+ * adjusts the length byte accordingly.  It is not an error to process a
+ * PNG file that has no iTXt chunks or one that has valid iTXt chunks;
+ * such files will simply be copied.
+ *
+ * Requires zlib (for crc32 and Z_NULL); build with
+ *
+ *     gcc -O -o png-fix-itxt png-fix-itxt.c -lz
+ *
+ * If you need to handle iTXt chunks larger than 500000 kbytes you must
+ * rebuild png-fix-itxt with a larger values of MAX_LENGTH (or a smaller value
+ * if you know you will never encounter such huge iTXt chunks).
+ */
+
+#include <stdio.h>
+#include <zlib.h>
+
+#define MAX_LENGTH 500000
+
+/* Read one character (inchar), also return octet (c), break if EOF */
+#define GETBREAK inchar=getchar(); \
+                 c=(inchar & 0xffU);\
+                 if (inchar != c) break
+int
+main(void)
+{
+   unsigned int i;
+   unsigned char buf[MAX_LENGTH];
+   unsigned long crc;
+   unsigned char c;
+   int inchar;
+
+/* Skip 8-byte signature */
+   for (i=8; i; i--)
+   {
+      GETBREAK;
+      putchar(c);
+   }
+
+if (inchar == c) /* !EOF */
+for (;;)
+ {
+   /* Read the length */
+   unsigned long length; /* must be 32 bits! */
+   GETBREAK; buf[0] = c; length  = c; length <<= 8;
+   GETBREAK; buf[1] = c; length += c; length <<= 8;
+   GETBREAK; buf[2] = c; length += c; length <<= 8;
+   GETBREAK; buf[3] = c; length += c;
+
+   /* Read the chunkname */
+   GETBREAK; buf[4] = c;
+   GETBREAK; buf[5] = c;
+   GETBREAK; buf[6] = c;
+   GETBREAK; buf[7] = c;
+
+
+   /* The iTXt chunk type expressed as integers is (105, 84, 88, 116) */
+   if (buf[4] == 105 && buf[5] == 84 && buf[6] == 88 && buf[7] == 116)
+   {
+      if (length >= MAX_LENGTH-12)
+         break;  /* To do: handle this more gracefully */
+
+      /* Initialize the CRC */
+      crc = crc32(0, Z_NULL, 0);
+
+      /* Copy the data bytes */
+      for (i=8; i < length + 12; i++)
+      {
+         GETBREAK; buf[i] = c;
+      }
+
+      if (inchar != c) /* EOF */
+         break;
+
+      /* Calculate the CRC */
+      crc = crc32(crc, buf+4, (uInt)length+4);
+
+      for (;;)
+      {
+        /* Check the CRC */
+        if (((crc >> 24) & 0xffU) == buf[length+8] &&
+            ((crc >> 16) & 0xffU) == buf[length+9] &&
+            ((crc >>  8) & 0xffU) == buf[length+10] &&
+            ((crc      ) & 0xffU) == buf[length+11])
+           break;
+
+        length++;
+
+        if (length >= MAX_LENGTH-12)
+           break;
+
+        GETBREAK;
+        buf[length+11] = c;
+
+        /* Update the CRC */
+        crc = crc32(crc, buf+7+length, 1);
+      }
+
+      if (inchar != c) /* EOF */
+         break;
+
+      /* Update length bytes */
+      buf[0] = (unsigned char)((length >> 24) & 0xffU);
+      buf[1] = (unsigned char)((length >> 16) & 0xffU);
+      buf[2] = (unsigned char)((length >>  8) & 0xffU);
+      buf[3] = (unsigned char)((length      ) & 0xffU);
+
+      /* Write the fixed iTXt chunk (length, name, data, crc) */
+      for (i=0; i<length+12; i++)
+         putchar(buf[i]);
+   }
+
+   else
+   {
+      if (inchar != c) /* EOF */
+         break;
+
+      /* Copy bytes that were already read (length and chunk name) */
+      for (i=0; i<8; i++)
+         putchar(buf[i]);
+
+      /* Copy data bytes and CRC */
+      for (i=8; i< length+12; i++)
+      {
+         GETBREAK;
+         putchar(c);
+      }
+
+      if (inchar != c) /* EOF */
+      {
+         break;
+      }
+
+   /* The IEND chunk type expressed as integers is (73, 69, 78, 68) */
+      if (buf[4] == 73 && buf[5] == 69 && buf[6] == 78 && buf[7] == 68)
+         break;
+   }
+
+   if (inchar != c) /* EOF */
+      break;
+
+   if (buf[4] == 73 && buf[5] == 69 && buf[6] == 78 && buf[7] == 68)
+     break;
+ }
+
+ return 0;
+}

contrib/tools/sRGB.h

@@ -1,9 +1,9 @@
 /*-
  * sRGB.h
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.0 [February 14, 2013]
  *
- * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * COPYRIGHT: Written by John Cunningham Bowler, 2013.
  * To the extent possible under law, the author has waived all copyright and
  * related or neighboring rights to this work.  This work is published from:
  * United States.

contrib/visupng/PngFile.c

@@ -136,7 +136,7 @@ BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
 
     /* create the two png(-info) structures */
 
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL,
+    png_ptr = png_create_read_struct(png_get_libpng_ver(NULL), NULL,
       (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
     if (!png_ptr)
     {
@@ -313,7 +313,7 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
 
     /* prepare the standard PNG structures */
 
-    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
+    png_ptr = png_create_write_struct(png_get_libpng_ver(NULL), NULL,
       (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
     if (!png_ptr)
     {

contrib/visupng/PngFile.h

@@ -17,7 +17,7 @@ void PngFileInitialize (HWND hwnd) ;
 BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
 BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
 
-BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData, 
+BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
                    int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor);
 BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
                    int iWidth, int iHeight, png_color BkgColor);

contrib/visupng/cexcept.h

@@ -1,11 +1,12 @@
 /*===
-cexcept.h 2.0.1 (2008-Jul-19-Sat)
+cexcept.h 2.0.1 (2008-Jul-19-Sat, modified 2015-Jun-03-Mon)
 http://www.nicemice.net/cexcept/
 Adam M. Costello
 http://www.nicemice.net/amc/
 
 An interface for exception-handling in ANSI C (C89 and subsequent ISO
-standards), developed jointly with Cosmin Truta.
+standards), developed jointly with Cosmin Truta.  Revised by John Bowler,
+June 2015, to declare exception_env and exception_prev "volatile".
 
     Copyright (c) 2000-2008 Adam M. Costello and Cosmin Truta.
     This software may be modified only if its author and version
@@ -210,7 +211,7 @@ struct exception_context { \
 
 #define Try \
   { \
-    jmp_buf *exception__prev, exception__env; \
+    jmp_buf * volatile exception__prev, exception__env; \
     exception__prev = the_exception_context->penv; \
     the_exception_context->penv = &exception__env; \
     if (setjmp(exception__env) == 0) { \

example.c

@@ -2,8 +2,8 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Maintained 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Maintained 1998-2014 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
  * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  * To the extent possible under law, the authors have waived
@@ -48,10 +48,11 @@ int main(int argc, const char **argv)
       png_image image; /* The control structure used by libpng */
 
       /* Initialize the 'png_image' structure. */
-      memset(&image, 0, sizeof image);
+      memset(&image, 0, (sizeof image));
+      image.version = PNG_IMAGE_VERSION;
 
       /* The first argument is the file to read: */
-      if (png_image_begin_read_from_file(&image, argv[1]))
+      if (png_image_begin_read_from_file(&image, argv[1]) != 0)
       {
          png_bytep buffer;
 
@@ -75,16 +76,28 @@ int main(int argc, const char **argv)
           * be supplied or the output buffer would have to be initialized to the
           * actual background of the image.
           *
-          * The final argument to png_image_finish_read is the 'row_stride' -
+          * The fourth argument to png_image_finish_read is the 'row_stride' -
           * this is the number of components allocated for the image in each
           * row.  It has to be at least as big as the value returned by
           * PNG_IMAGE_ROW_STRIDE, but if you just allocate space for the
           * default, minimum, size using PNG_IMAGE_SIZE as above you can pass
           * zero.
+          *
+          * The final argument is a pointer to a buffer for the colormap;
+          * colormaps have exactly the same format as a row of image pixels (so
+          * you choose what format to make the colormap by setting
+          * image.format).  A colormap is only returned if
+          * PNG_FORMAT_FLAG_COLORMAP is also set in image.format, so in this
+          * case NULL is passed as the final argument.  If you do want to force
+          * all images into an index/color-mapped format then you can use:
+          *
+          *    PNG_IMAGE_COLORMAP_SIZE(image)
+          *
+          * to find the maximum size of the colormap in bytes.
           */
          if (buffer != NULL &&
             png_image_finish_read(&image, NULL/*background*/, buffer,
-               0/*row_stride*/))
+               0/*row_stride*/, NULL/*colormap*/) != 0)
          {
             /* Now write the image out to the second argument.  In the write
              * call 'convert_to_8bit' allows 16-bit data to be squashed down to
@@ -92,7 +105,7 @@ int main(int argc, const char **argv)
              * to the 8-bit format.
              */
             if (png_image_write_to_file(&image, argv[2], 0/*convert_to_8bit*/,
-               buffer, 0/*row_stride*/))
+               buffer, 0/*row_stride*/, NULL/*colormap*/) != 0)
             {
                /* The image has been written successfully. */
                exit(0);
@@ -175,13 +188,13 @@ int main(int argc, const char **argv)
  *
  * Don't repeatedly convert between the 8-bit and 16-bit forms.  There is
  * significant data loss when 16-bit data is converted to the 8-bit encoding and
- * the current libpng implementation of convertion to 16-bit is also
+ * the current libpng implementation of conversion to 16-bit is also
  * significantly lossy.  The latter will be fixed in the future, but the former
  * is unavoidable - the 8-bit format just doesn't have enough resolution.
  */
 
 /* If your program needs more information from the PNG data it reads, or if you
- * need to do more complex transformations, or minimise transformations, on the
+ * need to do more complex transformations, or minimize transformations, on the
  * data you read, then you must use one of the several lower level libpng
  * interfaces.
  *
@@ -392,7 +405,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    /* Expand paletted or RGB images with transparency to full alpha channels
     * so the data will be available as RGBA quartets.
     */
-   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) != 0)
       png_set_tRNS_to_alpha(png_ptr);
 
    /* Set the background color to draw transparent and alpha images over.
@@ -404,7 +417,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
 
    png_color_16 my_background, *image_background;
 
-   if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+   if (png_get_bKGD(png_ptr, info_ptr, &image_background) != 0)
       png_set_background(png_ptr, image_background,
                          PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
    else
@@ -428,9 +441,9 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    /* If we don't have another value */
    else
    {
-      screen_gamma = 2.2;  /* A good guess for a PC monitor in a dimly
-                              lit room */
-      screen_gamma = 1.7 or 1.0;  /* A good guess for Mac systems */
+      screen_gamma = PNG_DEFAULT_sRGB;  /* A good guess for a PC monitor
+                                           in a dimly lit room */
+      screen_gamma = PNG_GAMMA_MAC_18 or 1.0; /* Good guesses for Mac systems */
    }
 
    /* Tell libpng to handle the gamma conversion for you.  The final call
@@ -441,12 +454,12 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
 
    int intent;
 
-   if (png_get_sRGB(png_ptr, info_ptr, &intent))
-      png_set_gamma(png_ptr, screen_gamma, 0.45455);
+   if (png_get_sRGB(png_ptr, info_ptr, &intent) != 0)
+      png_set_gamma(png_ptr, screen_gamma, PNG_DEFAULT_sRGB);
    else
    {
       double image_gamma;
-      if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
+      if (png_get_gAMA(png_ptr, info_ptr, &image_gamma) != 0)
          png_set_gamma(png_ptr, screen_gamma, image_gamma);
       else
          png_set_gamma(png_ptr, screen_gamma, 0.45455);
@@ -456,7 +469,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    /* Quantize RGB files down to 8 bit palette or reduce palettes
     * to the number of colors available on your screen.
     */
-   if (color_type & PNG_COLOR_MASK_COLOR)
+   if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       int num_palette;
       png_colorp palette;
@@ -471,7 +484,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
             MAX_SCREEN_COLORS, NULL, 0);
       }
       /* This reduces the image to the palette supplied in the file */
-      else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette))
+      else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) != 0)
       {
          png_uint_16p histogram = NULL;
 
@@ -481,7 +494,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
                         max_screen_colors, histogram, 0);
       }
    }
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#endif /* READ_QUANTIZE */
 
    /* Invert monochrome files to have 0 as white and 1 as black */
    png_set_invert_mono(png_ptr);
@@ -490,7 +503,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
     * [0,65535] to the original [0,7] or [0,31], or whatever range the
     * colors were originally in:
     */
-   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+   if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT) != 0)
    {
       png_color_8p sig_bit_p;
 
@@ -499,7 +512,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    }
 
    /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
-   if (color_type & PNG_COLOR_MASK_COLOR)
+   if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
       png_set_bgr(png_ptr);
 
    /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
@@ -519,7 +532,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* File is already open */
    number_passes = png_set_interlace_handling(png_ptr);
 #else
    number_passes = 1;
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
+#endif /* READ_INTERLACING */
 
 
    /* Optional call to gamma correct and add the background to the palette
@@ -731,7 +744,7 @@ row_callback(png_structp png_ptr, png_bytep new_row,
     * to pass the current row as new_row, and the function will combine
     * the old row and the new row.
     */
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
+#endif /* READ_INTERLACING */
 }
 
 end_callback(png_structp png_ptr, png_infop info)
@@ -833,7 +846,7 @@ void write_png(char *file_name /* , ... other image information ... */)
 
    /* Set the palette if there is one.  REQUIRED for indexed-color images */
    palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
-             * png_sizeof(png_color));
+             * (sizeof (png_color)));
    /* ... Set palette colors ... */
    png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
    /* You must not free palette here, because png_set_PLTE only makes a link to
@@ -864,25 +877,38 @@ void write_png(char *file_name /* , ... other image information ... */)
    png_set_gAMA(png_ptr, info_ptr, gamma);
 
    /* Optionally write comments into the image */
-   text_ptr[0].key = "Title";
-   text_ptr[0].text = "Mona Lisa";
-   text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
-   text_ptr[0].itxt_length = 0;
-   text_ptr[0].lang = NULL;
-   text_ptr[0].lang_key = NULL;
-   text_ptr[1].key = "Author";
-   text_ptr[1].text = "Leonardo DaVinci";
-   text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
-   text_ptr[1].itxt_length = 0;
-   text_ptr[1].lang = NULL;
-   text_ptr[1].lang_key = NULL;
-   text_ptr[2].key = "Description";
-   text_ptr[2].text = "<long text>";
-   text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
-   text_ptr[2].itxt_length = 0;
-   text_ptr[2].lang = NULL;
-   text_ptr[2].lang_key = NULL;
-   png_set_text(png_ptr, info_ptr, text_ptr, 3);
+   {
+      png_text text_ptr[3];
+
+      char key0[]="Title";
+      char text0[]="Mona Lisa";
+      text_ptr[0].key = key0;
+      text_ptr[0].text = text0;
+      text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
+      text_ptr[0].itxt_length = 0;
+      text_ptr[0].lang = NULL;
+      text_ptr[0].lang_key = NULL;
+
+      char key1[]="Author";
+      char text1[]="Leonardo DaVinci";
+      text_ptr[1].key = key1;
+      text_ptr[1].text = text1;
+      text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
+      text_ptr[1].itxt_length = 0;
+      text_ptr[1].lang = NULL;
+      text_ptr[1].lang_key = NULL;
+
+      char key2[]="Description";
+      char text2[]="<long text>";
+      text_ptr[2].key = key2;
+      text_ptr[2].text = text2;
+      text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
+      text_ptr[2].itxt_length = 0;
+      text_ptr[2].lang = NULL;
+      text_ptr[2].lang_key = NULL;
+
+      png_set_text(write_ptr, write_info_ptr, text_ptr, 3);
+   }
 
    /* Other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs */
 
@@ -906,7 +932,7 @@ void write_png(char *file_name /* , ... other image information ... */)
     */
 
    /* Once we write out the header, the compression type on the text
-    * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
+    * chunk gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
     * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
     * at the end.
     */
@@ -944,7 +970,7 @@ void write_png(char *file_name /* , ... other image information ... */)
    png_set_packswap(png_ptr);
 
    /* Turn on interlace handling if you are not using png_write_image() */
-   if (interlacing)
+   if (interlacing != 0)
       number_passes = png_set_interlace_handling(png_ptr);
 
    else
@@ -955,12 +981,16 @@ void write_png(char *file_name /* , ... other image information ... */)
     * use the first method if you aren't handling interlacing yourself.
     */
    png_uint_32 k, height, width;
-   png_byte image[height][width*bytes_per_pixel];
+
+   /* In this example, "image" is a one-dimensional array of bytes */
+   png_byte image[height*width*bytes_per_pixel];
+
    png_bytep row_pointers[height];
 
-   if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+   if (height > PNG_UINT_32_MAX/(sizeof (png_bytep)))
      png_error (png_ptr, "Image is too tall to process in memory");
 
+   /* Set up pointers into your "image" byte array */
    for (k = 0; k < height; k++)
      row_pointers[k] = image + k*width*bytes_per_pixel;
 

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "December 30, 2011"
+.TH LIBPNGPF 3 "July 13, 2015"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.0beta04
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.18rc03
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "December 30, 2011"
+.TH PNG 5 "July 13, 2015"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION

pngconf.h

@@ -1,9 +1,9 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.0beta04 - December 30, 2011
+ * libpng version 1.6.18rc03, (PENDING RELEASE)
  *
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -11,9 +11,7 @@
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  *
- */
-
-/* Any machine specific code is near the front of this file, so if you
+ * Any machine specific code is near the front of this file, so if you
  * are configuring libpng for a machine, you may want to read the section
  * starting here down to where it starts to typedef png_color, png_text,
  * and png_info.
@@ -67,8 +65,8 @@
 
 /* This controls optimization of the reading of 16 and 32 bit values
  * from PNG files.  It can be set on a per-app-file basis - it
- * just changes whether a macro is used to the function is called.
- * The library builder sets the default, if read functions are not
+ * just changes whether a macro is used when the function is called.
+ * The library builder sets the default; if read functions are not
  * built into the library the macro implementation is forced on.
  */
 #ifndef PNG_READ_INT_FUNCTIONS_SUPPORTED
@@ -178,18 +176,16 @@
  * ==========================
  * This code is used at build time to find PNG_IMPEXP, the API settings
  * and PNG_EXPORT_TYPE(), it may also set a macro to indicate the DLL
- * import processing is possible.  On Windows/x86 systems it also sets
+ * import processing is possible.  On Windows systems it also sets
  * compiler-specific macros to the values required to change the calling
  * conventions of the various functions.
  */
-#if ( defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
-      defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__) ) &&\
-    ( defined(_X86_) || defined(_X64_) || defined(_M_IX86) ||\
-      defined(_M_X64) || defined(_M_IA64) )
-  /* Windows system (DOS doesn't support DLLs) running on x86/x64.  Includes
-   * builds under Cygwin or MinGW.  Also includes Watcom builds but these need
-   * special treatment because they are not compatible with GCC or Visual C
-   * because of different calling conventions.
+#if defined(_Windows) || defined(_WINDOWS) || defined(WIN32) ||\
+    defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
+  /* Windows system (DOS doesn't support DLLs).  Includes builds under Cygwin or
+   * MinGW on any architecture currently supported by Windows.  Also includes
+   * Watcom builds but these need special treatment because they are not
+   * compatible with GCC or Visual C because of different calling conventions.
    */
 #  if PNG_API_RULE == 2
     /* If this line results in an error, either because __watcall is not
@@ -200,9 +196,12 @@
 #    define PNGCAPI __watcall
 #  endif
 
-#  if defined(__GNUC__) || (defined (_MSC_VER) && (_MSC_VER >= 800))
+#  if defined(__GNUC__) || (defined(_MSC_VER) && (_MSC_VER >= 800))
 #    define PNGCAPI __cdecl
 #    if PNG_API_RULE == 1
+       /* If this line results in an error __stdcall is not understood and
+        * PNG_API_RULE should not have been set to '1'.
+        */
 #      define PNGAPI __stdcall
 #    endif
 #  else
@@ -217,6 +216,7 @@
 #      define PNGAPI _stdcall
 #    endif
 #  endif /* compiler/api */
+
   /* NOTE: PNGCBAPI always defaults to PNGCAPI. */
 
 #  if defined(PNGAPI) && !defined(PNG_USER_PRIVATEBUILD)
@@ -240,7 +240,7 @@
 #    endif
 #  endif /* compiler */
 
-#else /* !Windows/x86 */
+#else /* !Windows */
 #  if (defined(__IBMC__) || defined(__IBMCPP__)) && defined(__OS2__)
 #    define PNGAPI _System
 #  else /* !Windows/x86 && !OS/2 */
@@ -295,11 +295,11 @@
     * table entries, so we discard it here.  See the .dfn files in the
     * scripts directory.
     */
-#ifndef PNG_EXPORTA
 
-#  define PNG_EXPORTA(ordinal, type, name, args, attributes)\
-      PNG_FUNCTION(PNG_EXPORT_TYPE(type),(PNGAPI name),PNGARG(args), \
-        extern attributes)
+#ifndef PNG_EXPORTA
+#  define PNG_EXPORTA(ordinal, type, name, args, attributes) \
+      PNG_FUNCTION(PNG_EXPORT_TYPE(type), (PNGAPI name), PNGARG(args), \
+      PNG_LINKAGE_API attributes)
 #endif
 
 /* ANSI-C (C90) does not permit a macro to be invoked with an empty argument,
@@ -307,7 +307,7 @@
  */
 #define PNG_EMPTY /*empty list*/
 
-#define PNG_EXPORT(ordinal, type, name, args)\
+#define PNG_EXPORT(ordinal, type, name, args) \
    PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
 
 /* Use PNG_REMOVED to comment out a removed interface. */
@@ -339,31 +339,61 @@
    * version 1.2.41.  Disabling these removes the warnings but may also produce
    * less efficient code.
    */
-#  if defined(__GNUC__)
+#  if defined(__clang__) && defined(__has_attribute)
+     /* Clang defines both __clang__ and __GNUC__. Check __clang__ first. */
+#    if !defined(PNG_USE_RESULT) && __has_attribute(__warn_unused_result__)
+#      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+#    endif
+#    if !defined(PNG_NORETURN) && __has_attribute(__noreturn__)
+#      define PNG_NORETURN __attribute__((__noreturn__))
+#    endif
+#    if !defined(PNG_ALLOCATED) && __has_attribute(__malloc__)
+#      define PNG_ALLOCATED __attribute__((__malloc__))
+#    endif
+#    if !defined(PNG_DEPRECATED) && __has_attribute(__deprecated__)
+#      define PNG_DEPRECATED __attribute__((__deprecated__))
+#    endif
+#    if !defined(PNG_PRIVATE)
+#      ifdef __has_extension
+#        if __has_extension(attribute_unavailable_with_message)
+#          define PNG_PRIVATE __attribute__((__unavailable__(\
+             "This function is not exported by libpng.")))
+#        endif
+#      endif
+#    endif
+#    ifndef PNG_RESTRICT
+#      define PNG_RESTRICT __restrict
+#    endif
+
+#  elif defined(__GNUC__)
 #    ifndef PNG_USE_RESULT
 #      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
 #    endif
 #    ifndef PNG_NORETURN
 #      define PNG_NORETURN   __attribute__((__noreturn__))
 #    endif
-#    ifndef PNG_ALLOCATED
-#      define PNG_ALLOCATED  __attribute__((__malloc__))
-#    endif
-#    ifndef PNG_DEPRECATED
-#      define PNG_DEPRECATED __attribute__((__deprecated__))
-#    endif
-#    ifndef PNG_PRIVATE
-#      if 0 /* Doesn't work so we use deprecated instead*/
-#        define PNG_PRIVATE \
-          __attribute__((warning("This function is not exported by libpng.")))
-#      else
-#        define PNG_PRIVATE \
-          __attribute__((__deprecated__))
+#    if __GNUC__ >= 3
+#      ifndef PNG_ALLOCATED
+#        define PNG_ALLOCATED  __attribute__((__malloc__))
 #      endif
-#    endif
-#    ifndef PNG_RESTRICT
-#      define PNG_RESTRICT __restrict
-#    endif
+#      ifndef PNG_DEPRECATED
+#        define PNG_DEPRECATED __attribute__((__deprecated__))
+#      endif
+#      ifndef PNG_PRIVATE
+#        if 0 /* Doesn't work so we use deprecated instead*/
+#          define PNG_PRIVATE \
+            __attribute__((warning("This function is not exported by libpng.")))
+#        else
+#          define PNG_PRIVATE \
+            __attribute__((__deprecated__))
+#        endif
+#      endif
+#      if ((__GNUC__ > 3) || !defined(__GNUC_MINOR__) || (__GNUC_MINOR__ >= 1))
+#        ifndef PNG_RESTRICT
+#          define PNG_RESTRICT __restrict
+#        endif
+#      endif /* __GNUC__.__GNUC_MINOR__ > 3.0 */
+#    endif /* __GNUC__ >= 3 */
 
 #  elif defined(_MSC_VER)  && (_MSC_VER >= 1300)
 #    ifndef PNG_USE_RESULT
@@ -393,7 +423,7 @@
 #    ifndef PNG_RESTRICT
 #      define PNG_RESTRICT __restrict
 #    endif
-#  endif /* _MSC_VER */
+#  endif
 #endif /* PNG_PEDANTIC_WARNINGS */
 
 #ifndef PNG_DEPRECATED
@@ -411,10 +441,14 @@
 #ifndef PNG_PRIVATE
 #  define PNG_PRIVATE     /* This is a private libpng function */
 #endif
+#ifndef PNG_RESTRICT
+#  define PNG_RESTRICT    /* The C99 "restrict" feature */
+#endif
+
 #ifndef PNG_FP_EXPORT     /* A floating point API. */
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 #     define PNG_FP_EXPORT(ordinal, type, name, args)\
-         PNG_EXPORT(ordinal, type, name, args)
+         PNG_EXPORT(ordinal, type, name, args);
 #  else                   /* No floating point APIs */
 #     define PNG_FP_EXPORT(ordinal, type, name, args)
 #  endif
@@ -422,7 +456,7 @@
 #ifndef PNG_FIXED_EXPORT  /* A fixed point API. */
 #  ifdef PNG_FIXED_POINT_SUPPORTED
 #     define PNG_FIXED_EXPORT(ordinal, type, name, args)\
-         PNG_EXPORT(ordinal, type, name, args)
+         PNG_EXPORT(ordinal, type, name, args);
 #  else                   /* No fixed point APIs */
 #     define PNG_FIXED_EXPORT(ordinal, type, name, args)
 #  endif
@@ -465,9 +499,9 @@
 #  error "libpng requires an unsigned 16 bit type"
 #endif
 
-#if INT_MIN < -2147483646 && INT_MAX > 2147483646 
+#if INT_MIN < -2147483646 && INT_MAX > 2147483646
    typedef int png_int_32;
-#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646 
+#elif LONG_MIN < -2147483646 && LONG_MAX > 2147483646
    typedef long int png_int_32;
 #else
 #  error "libpng requires a signed 32 bit (or more) type"
@@ -513,7 +547,7 @@ typedef ptrdiff_t png_ptrdiff_t;
  * png_uint_32) should be explicitly applied; however, we do not expect to
  * encounter practical situations that require such conversions.
  *
- * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than 
+ * PNG_SMALL_SIZE_T must be defined if the maximum value of size_t is less than
  * 4294967295 - i.e. less than the maximum value of png_uint_32.
  */
 #ifdef PNG_SMALL_SIZE_T
@@ -522,12 +556,6 @@ typedef ptrdiff_t png_ptrdiff_t;
    typedef png_size_t png_alloc_size_t;
 #endif
 
-/* This macro makes the sizeof operator look and behave like a function, except
- * that it can take a type without the enclosing () as an argument so long as
- * the type contains no "," characters.
- */
-#define png_sizeof(x) (sizeof (x))
-
 /* Prior to 1.6.0 libpng offered limited support for Microsoft C compiler
  * implementations of Intel CPU specific support of user-mode segmented address
  * spaces, where 16-bit pointers address more than 65536 bytes of memory using

pngdebug.h

@@ -1,12 +1,11 @@
 
 /* pngdebug.h - Debugging macros for libpng, also used in pngtest.c
  *
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.8 [December 19, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -25,7 +24,7 @@
  *   (actually ((void)0)).
  *
  *   level: level of detail of message, starting at 0.  A level 'n'
- *          message is preceded by 'n' tab characters (not implemented
+ *          message is preceded by 'n' 3-space indentations (not implemented
  *          on Microsoft compilers unless PNG_DEBUG_FILE is also
  *          defined, to allow debug DLL compilation with no standard IO).
  *   message: a printf(3) style text string.  A trailing '\n' is added
@@ -77,32 +76,29 @@
 #      endif /* PNG_DEBUG_FILE */
 
 #      if (PNG_DEBUG > 1)
-/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on
- * non-ISO compilers
- */
 #        ifdef __STDC__
 #          ifndef png_debug
 #            define png_debug(l,m) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : "")))); \
        } while (0)
 #          endif
 #          ifndef png_debug1
 #            define png_debug1(l,m,p1) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1); \
        } while (0)
 #          endif
 #          ifndef png_debug2
 #            define png_debug2(l,m,p1,p2) \
        do { \
        int num_tabs=l; \
-       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
-         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
+       fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "   " : \
+         (num_tabs==2 ? "      " : (num_tabs>2 ? "         " : ""))),p1,p2);\
        } while (0)
 #          endif
 #        else /* __STDC __ */

pngerror.c

@@ -1,8 +1,8 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -27,7 +27,7 @@ static PNG_FUNCTION(void, png_default_error,PNGARG((png_const_structrp png_ptr,
 static void /* PRIVATE */
 png_default_warning PNGARG((png_const_structrp png_ptr,
    png_const_charp warning_message));
-#endif /* PNG_WARNINGS_SUPPORTED */
+#endif /* WARNINGS */
 
 /* This function is called whenever there is a fatal error.  This function
  * should not be changed.  If there is a need to handle errors differently,
@@ -43,8 +43,8 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
    char msg[16];
    if (png_ptr != NULL)
    {
-      if (png_ptr->flags&
-         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+      if ((png_ptr->flags &
+         (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0
       {
          if (*error_message == PNG_LITERAL_SHARP)
          {
@@ -54,7 +54,7 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
                if (error_message[offset] == ' ')
                   break;
 
-            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+            if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
             {
                int i;
                for (i = 0; i < offset - 1; i++)
@@ -69,7 +69,7 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
 
       else
       {
-         if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+         if ((png_ptr->flags & PNG_FLAG_STRIP_ERROR_TEXT) != 0)
          {
             msg[0] = '0';
             msg[1] = '\0';
@@ -80,7 +80,8 @@ png_error,(png_const_structrp png_ptr, png_const_charp error_message),
    }
 #endif
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr), error_message);
+      (*(png_ptr->error_fn))(png_constcast(png_structrp,png_ptr),
+          error_message);
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
@@ -102,7 +103,7 @@ png_err,(png_const_structrp png_ptr),PNG_NORETURN)
       use the default handler, which will not return. */
    png_default_error(png_ptr, "");
 }
-#endif /* PNG_ERROR_TEXT_SUPPORTED */
+#endif /* ERROR_TEXT */
 
 /* Utility to safely appends strings to a buffer.  This never errors out so
  * error checking is not required in the caller.
@@ -151,7 +152,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
          case PNG_NUMBER_FORMAT_fixed:
             /* Needs five digits (the fraction) */
             mincount = 5;
-            if (output || number % 10 != 0)
+            if (output != 0 || number % 10 != 0)
             {
                *--end = digits[number % 10];
                output = 1;
@@ -162,7 +163,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
          case PNG_NUMBER_FORMAT_02u:
             /* Expects at least 2 digits. */
             mincount = 2;
-            /* fall through */
+            /* FALL THROUGH */
 
          case PNG_NUMBER_FORMAT_u:
             *--end = digits[number % 10];
@@ -172,7 +173,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
          case PNG_NUMBER_FORMAT_02x:
             /* This format expects at least two digits */
             mincount = 2;
-            /* fall through */
+            /* FALL THROUGH */
 
          case PNG_NUMBER_FORMAT_x:
             *--end = digits[number & 0xf];
@@ -188,13 +189,13 @@ png_format_number(png_const_charp start, png_charp end, int format,
       ++count;
 
       /* Float a fixed number here: */
-      if (format == PNG_NUMBER_FORMAT_fixed) if (count == 5) if (end > start)
+      if ((format == PNG_NUMBER_FORMAT_fixed) && (count == 5) && (end > start))
       {
          /* End of the fraction, but maybe nothing was output?  In that case
           * drop the decimal point.  If the number is a true zero handle that
           * here.
           */
-         if (output)
+         if (output != 0)
             *--end = '.';
          else if (number == 0) /* and !output */
             *--end = '0';
@@ -218,8 +219,8 @@ png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
    if (png_ptr != NULL)
    {
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-   if (png_ptr->flags&
-       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+   if ((png_ptr->flags &
+       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT)) != 0)
 #endif
       {
          if (*warning_message == PNG_LITERAL_SHARP)
@@ -283,35 +284,40 @@ void
 png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
    png_const_charp message)
 {
-   /* The internal buffer is just 128 bytes - enough for all our messages,
-    * overflow doesn't happen because this code checks!
+   /* The internal buffer is just 192 bytes - enough for all our messages,
+    * overflow doesn't happen because this code checks!  If someone figures
+    * out how to send us a message longer than 192 bytes, all that will
+    * happen is that the message will be truncated appropriately.
     */
-   size_t i;
-   char msg[128];
+   size_t i = 0; /* Index in the msg[] buffer: */
+   char msg[192];
 
-   for (i=0; i<(sizeof msg)-1 && *message != '\0'; ++i)
+   /* Each iteration through the following loop writes at most one character
+    * to msg[i++] then returns here to validate that there is still space for
+    * the trailing '\0'.  It may (in the case of a parameter) read more than
+    * one character from message[]; it must check for '\0' and continue to the
+    * test if it finds the end of string.
+    */
+   while (i<(sizeof msg)-1 && *message != '\0')
    {
-      if (*message == '@')
+      /* '@' at end of string is now just printed (previously it was skipped);
+       * it is an error in the calling code to terminate the string with @.
+       */
+      if (p != NULL && *message == '@' && message[1] != '\0')
       {
-         int parameter = -1;
-         switch (*++message)
-         {
-            case '1':
-               parameter = 0;
-               break;
+         int parameter_char = *++message; /* Consume the '@' */
+         static const char valid_parameters[] = "123456789";
+         int parameter = 0;
 
-            case '2':
-               parameter = 1;
-               break;
+         /* Search for the parameter digit, the index in the string is the
+          * parameter to use.
+          */
+         while (valid_parameters[parameter] != parameter_char &&
+            valid_parameters[parameter] != '\0')
+            ++parameter;
 
-            case '\0':
-               continue; /* To break out of the for loop above. */
-
-            default:
-               break;
-         }
-
-         if (parameter >= 0 && parameter < PNG_WARNING_PARAMETER_COUNT)
+         /* If the parameter digit is out of range it will just get printed. */
+         if (parameter < PNG_WARNING_PARAMETER_COUNT)
          {
             /* Append this parameter */
             png_const_charp parm = p[parameter];
@@ -321,47 +327,101 @@ png_formatted_warning(png_const_structrp png_ptr, png_warning_parameters p,
              * that parm[] has been initialized, so there is no guarantee of a
              * trailing '\0':
              */
-            for (; i<(sizeof msg)-1 && parm != '\0' && parm < pend; ++i)
-               msg[i] = *parm++;
+            while (i<(sizeof msg)-1 && *parm != '\0' && parm < pend)
+               msg[i++] = *parm++;
 
+            /* Consume the parameter digit too: */
             ++message;
             continue;
          }
 
          /* else not a parameter and there is a character after the @ sign; just
-          * copy that.
+          * copy that.  This is known not to be '\0' because of the test above.
           */
       }
 
       /* At this point *message can't be '\0', even in the bad parameter case
        * above where there is a lone '@' at the end of the message string.
        */
-      msg[i] = *message++;
+      msg[i++] = *message++;
    }
 
    /* i is always less than (sizeof msg), so: */
    msg[i] = '\0';
 
-   /* And this is the formatted message: */
+   /* And this is the formatted message. It may be larger than
+    * PNG_MAX_ERROR_TEXT, but that is only used for 'chunk' errors and these
+    * are not (currently) formatted.
+    */
    png_warning(png_ptr, msg);
 }
-#endif /* PNG_WARNINGS_SUPPORTED */
+#endif /* WARNINGS */
 
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 void PNGAPI
 png_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
 {
-  if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
+   {
+#     ifdef PNG_READ_SUPPORTED
+         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+            png_ptr->chunk_name != 0)
+            png_chunk_warning(png_ptr, error_message);
+         else
+#     endif
+      png_warning(png_ptr, error_message);
+   }
+
+   else
+   {
+#     ifdef PNG_READ_SUPPORTED
+         if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0 &&
+            png_ptr->chunk_name != 0)
+            png_chunk_error(png_ptr, error_message);
+         else
+#     endif
+      png_error(png_ptr, error_message);
+   }
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+
+void /* PRIVATE */
+png_app_warning(png_const_structrp png_ptr, png_const_charp error_message)
+{
+  if ((png_ptr->flags & PNG_FLAG_APP_WARNINGS_WARN) != 0)
      png_warning(png_ptr, error_message);
   else
      png_error(png_ptr, error_message);
-}
-#endif
 
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+
+void /* PRIVATE */
+png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
+{
+  if ((png_ptr->flags & PNG_FLAG_APP_ERRORS_WARN) != 0)
+     png_warning(png_ptr, error_message);
+  else
+     png_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
+}
+#endif /* BENIGN_ERRORS */
+
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
 /* These utilities are used internally to build an error message that relates
  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
- * this is used to prefix the message.  The message is limited in length
- * to 63 bytes, the name characters are output as hex digits wrapped in []
+ * which is used to prefix the message.  The message is limited in length
+ * to 63 bytes. The name characters are output as hex digits wrapped in []
  * if the character is invalid.
  */
 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
@@ -370,8 +430,6 @@ static PNG_CONST char png_digit[16] = {
    'A', 'B', 'C', 'D', 'E', 'F'
 };
 
-#define PNG_MAX_ERROR_TEXT 64
-#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED)
 static void /* PRIVATE */
 png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
     error_message)
@@ -384,7 +442,7 @@ png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
       int c = (int)(chunk_name >> ishift) & 0xff;
 
       ishift -= 8;
-      if (isnonalpha(c))
+      if (isnonalpha(c) != 0)
       {
          buffer[iout++] = PNG_LITERAL_LEFT_SQUARE_BRACKET;
          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
@@ -415,7 +473,7 @@ png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
       buffer[iout] = '\0';
    }
 }
-#endif /* PNG_WARNINGS_SUPPORTED || PNG_ERROR_TEXT_SUPPORTED */
+#endif /* WARNINGS || ERROR_TEXT */
 
 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED)
 PNG_FUNCTION(void,PNGAPI
@@ -432,7 +490,7 @@ png_chunk_error,(png_const_structrp png_ptr, png_const_charp error_message),
       png_error(png_ptr, msg);
    }
 }
-#endif /* PNG_READ_SUPPORTED && PNG_ERROR_TEXT_SUPPORTED */
+#endif /* READ && ERROR_TEXT */
 
 #ifdef PNG_WARNINGS_SUPPORTED
 void PNGAPI
@@ -448,21 +506,65 @@ png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
       png_warning(png_ptr, msg);
    }
 }
-#endif /* PNG_WARNINGS_SUPPORTED */
+#endif /* WARNINGS */
 
 #ifdef PNG_READ_SUPPORTED
 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
 void PNGAPI
-png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp error_message)
+png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp
+    error_message)
 {
-   if (png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN)
+   if ((png_ptr->flags & PNG_FLAG_BENIGN_ERRORS_WARN) != 0)
       png_chunk_warning(png_ptr, error_message);
 
    else
       png_chunk_error(png_ptr, error_message);
+
+#  ifndef PNG_ERROR_TEXT_SUPPORTED
+      PNG_UNUSED(error_message)
+#  endif
 }
 #endif
-#endif /* PNG_READ_SUPPORTED */
+#endif /* READ */
+
+void /* PRIVATE */
+png_chunk_report(png_const_structrp png_ptr, png_const_charp message, int error)
+{
+#  ifndef PNG_WARNINGS_SUPPORTED
+      PNG_UNUSED(message)
+#  endif
+
+   /* This is always supported, but for just read or just write it
+    * unconditionally does the right thing.
+    */
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+#  endif
+
+#  ifdef PNG_READ_SUPPORTED
+      {
+         if (error < PNG_CHUNK_ERROR)
+            png_chunk_warning(png_ptr, message);
+
+         else
+            png_chunk_benign_error(png_ptr, message);
+      }
+#  endif
+
+#  if defined(PNG_READ_SUPPORTED) && defined(PNG_WRITE_SUPPORTED)
+      else if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
+#  endif
+
+#  ifdef PNG_WRITE_SUPPORTED
+      {
+         if (error < PNG_CHUNK_WRITE_ERROR)
+            png_app_warning(png_ptr, message);
+
+         else
+            png_app_error(png_ptr, message);
+      }
+#  endif
+}
 
 #ifdef PNG_ERROR_TEXT_SUPPORTED
 #ifdef PNG_FLOATING_POINT_SUPPORTED
@@ -473,13 +575,14 @@ png_fixed_error,(png_const_structrp png_ptr, png_const_charp name),PNG_NORETURN)
 #  define fixed_message_ln ((sizeof fixed_message)-1)
    int  iin;
    char msg[fixed_message_ln+PNG_MAX_ERROR_TEXT];
-   png_memcpy(msg, fixed_message, fixed_message_ln);
+   memcpy(msg, fixed_message, fixed_message_ln);
    iin = 0;
-   if (name != NULL) while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
-   {
-      msg[fixed_message_ln + iin] = name[iin];
-      ++iin;
-   }
+   if (name != NULL)
+      while (iin < (PNG_MAX_ERROR_TEXT-1) && name[iin] != 0)
+      {
+         msg[fixed_message_ln + iin] = name[iin];
+         ++iin;
+      }
    msg[fixed_message_ln + iin] = 0;
    png_error(png_ptr, msg);
 }
@@ -511,7 +614,7 @@ png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
    {
       png_ptr->jmp_buf_size = 0; /* not allocated */
 
-      if (jmp_buf_size <= sizeof png_ptr->jmp_buf_local)
+      if (jmp_buf_size <= (sizeof png_ptr->jmp_buf_local))
          png_ptr->jmp_buf_ptr = &png_ptr->jmp_buf_local;
 
       else
@@ -532,7 +635,7 @@ png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn,
 
       if (size == 0)
       {
-         size = sizeof png_ptr->jmp_buf_local;
+         size = (sizeof png_ptr->jmp_buf_local);
          if (png_ptr->jmp_buf_ptr != &png_ptr->jmp_buf_local)
          {
             /* This is an internal error in libpng: somehow we have been left
@@ -655,11 +758,20 @@ PNG_FUNCTION(void,PNGAPI
 png_longjmp,(png_const_structrp png_ptr, int val),PNG_NORETURN)
 {
 #ifdef PNG_SETJMP_SUPPORTED
-   if (png_ptr && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
+   if (png_ptr != NULL && png_ptr->longjmp_fn != NULL &&
+       png_ptr->jmp_buf_ptr != NULL)
       png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(val)
 #endif
 
-   /* Here if not setjmp support or if png_ptr is null. */
+   /* If control reaches this point, png_longjmp() must not return. The only
+    * choice is to terminate the whole process (or maybe the thread); to do
+    * this the ANSI-C abort() function is used unless a different method is 
+    * implemented by overriding the default configuration setting for
+    * PNG_ABORT().
+    */
    PNG_ABORT();
 }
 
@@ -712,7 +824,7 @@ png_default_warning(png_const_structrp png_ptr, png_const_charp warning_message)
 #endif
    PNG_UNUSED(png_ptr) /* Make compiler happy */
 }
-#endif /* PNG_WARNINGS_SUPPORTED */
+#endif /* WARNINGS */
 
 /* This function is called when the application wants to use another method
  * of handling errors and warnings.  Note that the error function MUST NOT
@@ -763,14 +875,14 @@ png_set_strip_error_numbers(png_structrp png_ptr, png_uint_32 strip_mode)
 }
 #endif
 
-#if defined PNG_SIMPLIFIED_READ_SUPPORTED ||\
-   defined PNG_SIMPLIFIED_WRITE_SUPPORTED
+#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) ||\
+   defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
    /* Currently the above both depend on SETJMP_SUPPORTED, however it would be
     * possible to implement without setjmp support just so long as there is some
     * way to handle the error return here:
     */
-PNG_FUNCTION(void /* PRIVATE */,
-png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
+PNG_FUNCTION(void /* PRIVATE */, (PNGCBAPI
+png_safe_error),(png_structp png_nonconst_ptr, png_const_charp error_message),
    PNG_NORETURN)
 {
    const png_const_structrp png_ptr = png_nonconst_ptr;
@@ -781,8 +893,8 @@ png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
     */
    if (image != NULL)
    {
-      png_safecat(image->message, sizeof image->message, 0, error_message);
-      image->warning_or_error = 1;
+      png_safecat(image->message, (sizeof image->message), 0, error_message);
+      image->warning_or_error |= PNG_IMAGE_ERROR;
 
       /* Retrieve the jmp_buf from within the png_control, making this work for
        * C++ compilation too is pretty tricky: C++ wants a pointer to the first
@@ -793,9 +905,10 @@ png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
 
       /* Missing longjmp buffer, the following is to help debugging: */
       {
-         size_t pos = png_safecat(image->message, sizeof image->message, 0,
+         size_t pos = png_safecat(image->message, (sizeof image->message), 0,
             "bad longjmp: ");
-         png_safecat(image->message, sizeof image->message, pos, error_message);
+         png_safecat(image->message, (sizeof image->message), pos,
+             error_message);
       }
    }
 
@@ -804,7 +917,7 @@ png_safe_error,(png_structp png_nonconst_ptr, png_const_charp error_message),
 }
 
 #ifdef PNG_WARNINGS_SUPPORTED
-void /* PRIVATE */
+void /* PRIVATE */ PNGCBAPI
 png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
 {
    const png_const_structrp png_ptr = png_nonconst_ptr;
@@ -813,16 +926,16 @@ png_safe_warning(png_structp png_nonconst_ptr, png_const_charp warning_message)
    /* A warning is only logged if there is no prior warning or error. */
    if (image->warning_or_error == 0)
    {
-      png_safecat(image->message, sizeof image->message, 0, warning_message);
-      image->warning_or_error = 2;
+      png_safecat(image->message, (sizeof image->message), 0, warning_message);
+      image->warning_or_error |= PNG_IMAGE_WARNING;
    }
 }
 #endif
 
 int /* PRIVATE */
-png_safe_execute(png_imagep imageIn, int (*function)(png_voidp), png_voidp arg)
+png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
 {
-   volatile png_imagep image = imageIn;
+   volatile png_imagep image = image_in;
    volatile int result;
    volatile png_voidp saved_error_buf;
    jmp_buf safe_jmpbuf;
@@ -831,7 +944,7 @@ png_safe_execute(png_imagep imageIn, int (*function)(png_voidp), png_voidp arg)
    saved_error_buf = image->opaque->error_buf;
    result = setjmp(safe_jmpbuf) == 0;
 
-   if (result)
+   if (result != 0)
    {
 
       image->opaque->error_buf = safe_jmpbuf;
@@ -841,10 +954,10 @@ png_safe_execute(png_imagep imageIn, int (*function)(png_voidp), png_voidp arg)
    image->opaque->error_buf = saved_error_buf;
 
    /* And do the cleanup prior to any failure return. */
-   if (!result)
+   if (result == 0)
       png_image_free(image);
 
    return result;
 }
-#endif /* SIMPLIFIED READ/WRITE */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */
+#endif /* READ || WRITE */

pngget.c

@@ -1,8 +1,8 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.17 [March 26, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -112,10 +112,12 @@ png_get_compression_type(png_const_structrp png_ptr, png_const_inforp info_ptr)
 }
 
 png_uint_32 PNGAPI
-png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
       {
          png_debug1(1, "in %s retrieval function",
              "png_get_x_pixels_per_meter");
@@ -123,16 +125,21 @@ png_get_x_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr
          if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
             return (info_ptr->x_pixels_per_unit);
       }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
 }
 
 png_uint_32 PNGAPI
-png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp
+    info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       png_debug1(1, "in %s retrieval function",
           "png_get_y_pixels_per_meter");
@@ -140,6 +147,9 @@ png_get_y_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr
       if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
          return (info_ptr->y_pixels_per_unit);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -149,7 +159,8 @@ png_uint_32 PNGAPI
 png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
 
@@ -157,6 +168,9 @@ png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
           info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
          return (info_ptr->x_pixels_per_unit);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -164,10 +178,12 @@ png_get_pixels_per_meter(png_const_structrp png_ptr, png_const_inforp info_ptr)
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
 float PNGAPI
-png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp info_ptr)
+png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp
+   info_ptr)
 {
 #ifdef PNG_READ_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
 
@@ -175,6 +191,9 @@ png_get_pixel_aspect_ratio(png_const_structrp png_ptr, png_const_inforp info_ptr
          return ((float)((float)info_ptr->y_pixels_per_unit
              /(float)info_ptr->x_pixels_per_unit));
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return ((float)0.0);
@@ -187,10 +206,11 @@ png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
     png_const_inforp info_ptr)
 {
 #ifdef PNG_READ_pHYs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)
-       && info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0
-       && info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX
-       && info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0 &&
+       info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0 &&
+       info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX &&
+       info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
    {
       png_fixed_point res;
 
@@ -200,9 +220,12 @@ png_get_pixel_aspect_ratio_fixed(png_const_structrp png_ptr,
        * range of 0..2^31-1; otherwise the cast might overflow.
        */
       if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
-          (png_int_32)info_ptr->x_pixels_per_unit))
+          (png_int_32)info_ptr->x_pixels_per_unit) != 0)
          return res;
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return 0;
@@ -213,13 +236,17 @@ png_int_32 PNGAPI
 png_get_x_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
 
       if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
          return (info_ptr->x_offset);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -229,13 +256,17 @@ png_int_32 PNGAPI
 png_get_y_offset_microns(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
 
       if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
          return (info_ptr->y_offset);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -245,13 +276,17 @@ png_int_32 PNGAPI
 png_get_x_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels");
 
       if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
          return (info_ptr->x_offset);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -261,13 +296,17 @@ png_int_32 PNGAPI
 png_get_y_offset_pixels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
 #ifdef PNG_oFFs_SUPPORTED
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels");
 
       if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
          return (info_ptr->y_offset);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -298,7 +337,7 @@ ppi_from_ppm(png_uint_32 ppm)
     */
    png_fixed_point result;
    if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
-       5000))
+       5000) != 0)
       return result;
 
    /* Overflow. */
@@ -384,7 +423,8 @@ png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_uint_32 retval = 0;
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       png_debug1(1, "in %s retrieval function", "pHYs");
 
@@ -415,12 +455,13 @@ png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
    return (retval);
 }
-#endif /* PNG_pHYs_SUPPORTED */
-#endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
+#endif /* pHYs */
+#endif  /* INCH_CONVERSIONS */
 
 /* png_get_channels really belongs in here, too, but it's been around longer */
 
-#endif  /* PNG_EASY_ACCESS_SUPPORTED */
+#endif  /* EASY_ACCESS */
+
 
 png_byte PNGAPI
 png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
@@ -431,6 +472,7 @@ png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
    return (0);
 }
 
+#ifdef PNG_READ_SUPPORTED
 png_const_bytep PNGAPI
 png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
@@ -439,14 +481,16 @@ png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 
    return (NULL);
 }
+#endif
 
 #ifdef PNG_bKGD_SUPPORTED
 png_uint_32 PNGAPI
 png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
    png_color_16p *background)
 {
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
-       && background != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_bKGD) != 0 &&
+       background != NULL)
    {
       png_debug1(1, "in %s retrieval function", "bKGD");
 
@@ -463,87 +507,47 @@ png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr,
  * same time to correct the rgb grayscale coefficient defaults obtained from the
  * cHRM chunk in 1.5.4
  */
-png_uint_32 PNGFAPI
-png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
-    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
-    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
-    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
-    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
-    png_fixed_point *int_blue_Z)
-{
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
-   {
-      png_xy xy;
-      png_XYZ XYZ;
-
-      png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
-
-      xy.whitex = info_ptr->x_white;
-      xy.whitey = info_ptr->y_white;
-      xy.redx = info_ptr->x_red;
-      xy.redy = info_ptr->y_red;
-      xy.greenx = info_ptr->x_green;
-      xy.greeny = info_ptr->y_green;
-      xy.bluex = info_ptr->x_blue;
-      xy.bluey = info_ptr->y_blue;
-
-      /* The *_checked function handles error reporting, so just return 0 if
-       * there is a failure here.
-       */
-      if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
-      {
-         if (int_red_X != NULL)
-            *int_red_X = XYZ.redX;
-         if (int_red_Y != NULL)
-            *int_red_Y = XYZ.redY;
-         if (int_red_Z != NULL)
-            *int_red_Z = XYZ.redZ;
-         if (int_green_X != NULL)
-            *int_green_X = XYZ.greenX;
-         if (int_green_Y != NULL)
-            *int_green_Y = XYZ.greenY;
-         if (int_green_Z != NULL)
-            *int_green_Z = XYZ.greenZ;
-         if (int_blue_X != NULL)
-            *int_blue_X = XYZ.blueX;
-         if (int_blue_Y != NULL)
-            *int_blue_Y = XYZ.blueY;
-         if (int_blue_Z != NULL)
-            *int_blue_Z = XYZ.blueZ;
-
-         return (PNG_INFO_cHRM);
-      }
-   }
-
-   return (0);
-}
-
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32 PNGAPI
 png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr,
     double *white_x, double *white_y, double *red_x, double *red_y,
     double *green_x, double *green_y, double *blue_x, double *blue_y)
 {
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   /* Quiet API change: this code used to only return the end points if a cHRM
+    * chunk was present, but the end points can also come from iCCP or sRGB
+    * chunks, so in 1.6.0 the png_get_ APIs return the end points regardless and
+    * the png_set_ APIs merely check that set end points are mutually
+    * consistent.
+    */
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
    {
       png_debug1(1, "in %s retrieval function", "cHRM");
 
       if (white_x != NULL)
-         *white_x = png_float(png_ptr, info_ptr->x_white, "cHRM white X");
+         *white_x = png_float(png_ptr,
+            info_ptr->colorspace.end_points_xy.whitex, "cHRM white X");
       if (white_y != NULL)
-         *white_y = png_float(png_ptr, info_ptr->y_white, "cHRM white Y");
+         *white_y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_xy.whitey, "cHRM white Y");
       if (red_x != NULL)
-         *red_x = png_float(png_ptr, info_ptr->x_red, "cHRM red X");
+         *red_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redx,
+            "cHRM red X");
       if (red_y != NULL)
-         *red_y = png_float(png_ptr, info_ptr->y_red, "cHRM red Y");
+         *red_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.redy,
+            "cHRM red Y");
       if (green_x != NULL)
-         *green_x = png_float(png_ptr, info_ptr->x_green, "cHRM green X");
+         *green_x = png_float(png_ptr,
+            info_ptr->colorspace.end_points_xy.greenx, "cHRM green X");
       if (green_y != NULL)
-         *green_y = png_float(png_ptr, info_ptr->y_green, "cHRM green Y");
+         *green_y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_xy.greeny, "cHRM green Y");
       if (blue_x != NULL)
-         *blue_x = png_float(png_ptr, info_ptr->x_blue, "cHRM blue X");
+         *blue_x = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluex,
+            "cHRM blue X");
       if (blue_y != NULL)
-         *blue_y = png_float(png_ptr, info_ptr->y_blue, "cHRM blue Y");
+         *blue_y = png_float(png_ptr, info_ptr->colorspace.end_points_xy.bluey,
+            "cHRM blue Y");
       return (PNG_INFO_cHRM);
    }
 
@@ -556,30 +560,38 @@ png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
    double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
    double *blue_Z)
 {
-   png_XYZ XYZ;
-
-   if (png_get_cHRM_XYZ_fixed(png_ptr, info_ptr,
-      &XYZ.redX, &XYZ.redY, &XYZ.redZ, &XYZ.greenX, &XYZ.greenY, &XYZ.greenZ,
-      &XYZ.blueX, &XYZ.blueY, &XYZ.blueZ) & PNG_INFO_cHRM)
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
    {
+      png_debug1(1, "in %s retrieval function", "cHRM_XYZ(float)");
+
       if (red_X != NULL)
-         *red_X = png_float(png_ptr, XYZ.redX, "cHRM red X");
+         *red_X = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_X,
+            "cHRM red X");
       if (red_Y != NULL)
-         *red_Y = png_float(png_ptr, XYZ.redY, "cHRM red Y");
+         *red_Y = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Y,
+            "cHRM red Y");
       if (red_Z != NULL)
-         *red_Z = png_float(png_ptr, XYZ.redZ, "cHRM red Z");
+         *red_Z = png_float(png_ptr, info_ptr->colorspace.end_points_XYZ.red_Z,
+            "cHRM red Z");
       if (green_X != NULL)
-         *green_X = png_float(png_ptr, XYZ.greenX, "cHRM green X");
+         *green_X = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.green_X, "cHRM green X");
       if (green_Y != NULL)
-         *green_Y = png_float(png_ptr, XYZ.greenY, "cHRM green Y");
+         *green_Y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.green_Y, "cHRM green Y");
       if (green_Z != NULL)
-         *green_Z = png_float(png_ptr, XYZ.greenZ, "cHRM green Z");
+         *green_Z = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.green_Z, "cHRM green Z");
       if (blue_X != NULL)
-         *blue_X = png_float(png_ptr, XYZ.blueX, "cHRM blue X");
+         *blue_X = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_X, "cHRM blue X");
       if (blue_Y != NULL)
-         *blue_Y = png_float(png_ptr, XYZ.blueY, "cHRM blue Y");
+         *blue_Y = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_Y, "cHRM blue Y");
       if (blue_Z != NULL)
-         *blue_Z = png_float(png_ptr, XYZ.blueZ, "cHRM blue Z");
+         *blue_Z = png_float(png_ptr,
+            info_ptr->colorspace.end_points_XYZ.blue_Z, "cHRM blue Z");
       return (PNG_INFO_cHRM);
    }
 
@@ -588,6 +600,43 @@ png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr,
 #  endif
 
 #  ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
+    png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
+    png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
+    png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
+    png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
+    png_fixed_point *int_blue_Z)
+{
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
+   {
+      png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
+
+      if (int_red_X != NULL)
+         *int_red_X = info_ptr->colorspace.end_points_XYZ.red_X;
+      if (int_red_Y != NULL)
+         *int_red_Y = info_ptr->colorspace.end_points_XYZ.red_Y;
+      if (int_red_Z != NULL)
+         *int_red_Z = info_ptr->colorspace.end_points_XYZ.red_Z;
+      if (int_green_X != NULL)
+         *int_green_X = info_ptr->colorspace.end_points_XYZ.green_X;
+      if (int_green_Y != NULL)
+         *int_green_Y = info_ptr->colorspace.end_points_XYZ.green_Y;
+      if (int_green_Z != NULL)
+         *int_green_Z = info_ptr->colorspace.end_points_XYZ.green_Z;
+      if (int_blue_X != NULL)
+         *int_blue_X = info_ptr->colorspace.end_points_XYZ.blue_X;
+      if (int_blue_Y != NULL)
+         *int_blue_Y = info_ptr->colorspace.end_points_XYZ.blue_Y;
+      if (int_blue_Z != NULL)
+         *int_blue_Z = info_ptr->colorspace.end_points_XYZ.blue_Z;
+      return (PNG_INFO_cHRM);
+   }
+
+   return (0);
+}
+
 png_uint_32 PNGAPI
 png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
@@ -596,24 +645,25 @@ png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "cHRM");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_ENDPOINTS) != 0)
    {
       if (white_x != NULL)
-         *white_x = info_ptr->x_white;
+         *white_x = info_ptr->colorspace.end_points_xy.whitex;
       if (white_y != NULL)
-         *white_y = info_ptr->y_white;
+         *white_y = info_ptr->colorspace.end_points_xy.whitey;
       if (red_x != NULL)
-         *red_x = info_ptr->x_red;
+         *red_x = info_ptr->colorspace.end_points_xy.redx;
       if (red_y != NULL)
-         *red_y = info_ptr->y_red;
+         *red_y = info_ptr->colorspace.end_points_xy.redy;
       if (green_x != NULL)
-         *green_x = info_ptr->x_green;
+         *green_x = info_ptr->colorspace.end_points_xy.greenx;
       if (green_y != NULL)
-         *green_y = info_ptr->y_green;
+         *green_y = info_ptr->colorspace.end_points_xy.greeny;
       if (blue_x != NULL)
-         *blue_x = info_ptr->x_blue;
+         *blue_x = info_ptr->colorspace.end_points_xy.bluex;
       if (blue_y != NULL)
-         *blue_y = info_ptr->y_blue;
+         *blue_y = info_ptr->colorspace.end_points_xy.bluey;
       return (PNG_INFO_cHRM);
    }
 
@@ -623,35 +673,43 @@ png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
 #endif
 
 #ifdef PNG_gAMA_SUPPORTED
-png_uint_32 PNGFAPI
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
 png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     png_fixed_point *file_gamma)
 {
    png_debug1(1, "in %s retrieval function", "gAMA");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
-       && file_gamma != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+      file_gamma != NULL)
    {
-      *file_gamma = info_ptr->gamma;
+      *file_gamma = info_ptr->colorspace.gamma;
       return (PNG_INFO_gAMA);
    }
 
    return (0);
 }
+#  endif
+
 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32 PNGAPI
 png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr,
     double *file_gamma)
 {
-   png_fixed_point igamma;
-   png_uint_32 ok = png_get_gAMA_fixed(png_ptr, info_ptr, &igamma);
+   png_debug1(1, "in %s retrieval function", "gAMA(float)");
 
-   if (ok)
-      *file_gamma = png_float(png_ptr, igamma, "png_get_gAMA");
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_GAMMA) != 0 &&
+      file_gamma != NULL)
+   {
+      *file_gamma = png_float(png_ptr, info_ptr->colorspace.gamma,
+         "png_get_gAMA");
+      return (PNG_INFO_gAMA);
+   }
 
-   return ok;
+   return (0);
 }
-
 #  endif
 #endif
 
@@ -662,10 +720,10 @@ png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "sRGB");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
-       && file_srgb_intent != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->valid & PNG_INFO_sRGB) != 0 && file_srgb_intent != NULL)
    {
-      *file_srgb_intent = (int)info_ptr->srgb_intent;
+      *file_srgb_intent = info_ptr->colorspace.rendering_intent;
       return (PNG_INFO_sRGB);
    }
 
@@ -675,23 +733,24 @@ png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #ifdef PNG_iCCP_SUPPORTED
 png_uint_32 PNGAPI
-png_get_iCCP(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr,
     png_charpp name, int *compression_type,
     png_bytepp profile, png_uint_32 *proflen)
 {
    png_debug1(1, "in %s retrieval function", "iCCP");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
-       && name != NULL && compression_type != NULL && profile != NULL &&
-		 proflen != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_iCCP) != 0 &&
+       name != NULL && compression_type != NULL && profile != NULL &&
+           proflen != NULL)
    {
       *name = info_ptr->iccp_name;
       *profile = info_ptr->iccp_profile;
-      /* Compression_type is a dummy so the API won't have to change
-       * if we introduce multiple compression types later.
+      *proflen = png_get_uint_32(info_ptr->iccp_profile);
+      /* This is somewhat irrelevant since the profile data returned has
+       * actually been uncompressed.
        */
-      *proflen = info_ptr->iccp_proflen;
-      *compression_type = info_ptr->iccp_compression;
+      *compression_type = PNG_COMPRESSION_TYPE_BASE;
       return (PNG_INFO_iCCP);
    }
 
@@ -700,14 +759,14 @@ png_get_iCCP(png_const_structrp png_ptr, png_const_inforp info_ptr,
 #endif
 
 #ifdef PNG_sPLT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_sPLT(png_const_structrp png_ptr, png_const_inforp info_ptr,
+int PNGAPI
+png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr,
     png_sPLT_tpp spalettes)
 {
    if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
    {
       *spalettes = info_ptr->splt_palettes;
-      return ((png_uint_32)info_ptr->splt_palettes_num);
+      return info_ptr->splt_palettes_num;
    }
 
    return (0);
@@ -716,13 +775,13 @@ png_get_sPLT(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #ifdef PNG_hIST_SUPPORTED
 png_uint_32 PNGAPI
-png_get_hIST(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr,
     png_uint_16p *hist)
 {
    png_debug1(1, "in %s retrieval function", "hIST");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
-       && hist != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_hIST) != 0 && hist != NULL)
    {
       *hist = info_ptr->hist;
       return (PNG_INFO_hIST);
@@ -740,14 +799,20 @@ png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "IHDR");
 
-   if (png_ptr == NULL || info_ptr == NULL || width == NULL ||
-       height == NULL || bit_depth == NULL || color_type == NULL)
+   if (png_ptr == NULL || info_ptr == NULL)
       return (0);
 
-   *width = info_ptr->width;
-   *height = info_ptr->height;
-   *bit_depth = info_ptr->bit_depth;
-   *color_type = info_ptr->color_type;
+   if (width != NULL)
+       *width = info_ptr->width;
+
+   if (height != NULL)
+       *height = info_ptr->height;
+
+   if (bit_depth != NULL)
+       *bit_depth = info_ptr->bit_depth;
+
+   if (color_type != NULL)
+       *color_type = info_ptr->color_type;
 
    if (compression_type != NULL)
       *compression_type = info_ptr->compression_type;
@@ -777,8 +842,9 @@ png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "oFFs");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
-       && offset_x != NULL && offset_y != NULL && unit_type != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_oFFs) != 0 &&
+       offset_x != NULL && offset_y != NULL && unit_type != NULL)
    {
       *offset_x = info_ptr->x_offset;
       *offset_y = info_ptr->y_offset;
@@ -792,14 +858,15 @@ png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #ifdef PNG_pCAL_SUPPORTED
 png_uint_32 PNGAPI
-png_get_pCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr,
     png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
     png_charp *units, png_charpp *params)
 {
    png_debug1(1, "in %s retrieval function", "pCAL");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)
-       && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_pCAL) != 0 &&
+       purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
        nparams != NULL && units != NULL && params != NULL)
    {
       *purpose = info_ptr->pcal_purpose;
@@ -818,14 +885,14 @@ png_get_pCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #ifdef PNG_sCAL_SUPPORTED
 #  ifdef PNG_FIXED_POINT_SUPPORTED
-#    if (defined PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
-         (defined PNG_FLOATING_POINT_SUPPORTED)
+#    if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
+         defined(PNG_FLOATING_POINT_SUPPORTED)
 png_uint_32 PNGAPI
 png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, png_fixed_point *width, png_fixed_point *height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->valid & PNG_INFO_sCAL))
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
    {
       *unit = info_ptr->scal_unit;
       /*TODO: make this work without FP support; the API is currently eliminated
@@ -848,7 +915,7 @@ png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, double *width, double *height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->valid & PNG_INFO_sCAL))
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
    {
       *unit = info_ptr->scal_unit;
       *width = atof(info_ptr->scal_s_width);
@@ -864,7 +931,7 @@ png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr,
     int *unit, png_charpp width, png_charpp height)
 {
    if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->valid & PNG_INFO_sCAL))
+       (info_ptr->valid & PNG_INFO_sCAL) != 0)
    {
       *unit = info_ptr->scal_unit;
       *width = info_ptr->scal_s_width;
@@ -886,7 +953,7 @@ png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
    png_debug1(1, "in %s retrieval function", "pHYs");
 
    if (png_ptr != NULL && info_ptr != NULL &&
-       (info_ptr->valid & PNG_INFO_pHYs))
+       (info_ptr->valid & PNG_INFO_pHYs) != 0)
    {
       if (res_x != NULL)
       {
@@ -912,13 +979,13 @@ png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr,
 #endif /* pHYs */
 
 png_uint_32 PNGAPI
-png_get_PLTE(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr,
     png_colorp *palette, int *num_palette)
 {
    png_debug1(1, "in %s retrieval function", "PLTE");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
-       && palette != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_PLTE) != 0 && palette != NULL)
    {
       *palette = info_ptr->palette;
       *num_palette = info_ptr->num_palette;
@@ -936,8 +1003,8 @@ png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "sBIT");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
-       && sig_bit != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sBIT) != 0 && sig_bit != NULL)
    {
       *sig_bit = &(info_ptr->sig_bit);
       return (PNG_INFO_sBIT);
@@ -948,8 +1015,8 @@ png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr,
 #endif
 
 #ifdef PNG_TEXT_SUPPORTED
-png_uint_32 PNGAPI
-png_get_text(png_const_structrp png_ptr, png_const_inforp info_ptr,
+int PNGAPI
+png_get_text(png_const_structrp png_ptr, png_inforp info_ptr,
     png_textp *text_ptr, int *num_text)
 {
    if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
@@ -963,7 +1030,7 @@ png_get_text(png_const_structrp png_ptr, png_const_inforp info_ptr,
       if (num_text != NULL)
          *num_text = info_ptr->num_text;
 
-      return ((png_uint_32)info_ptr->num_text);
+      return info_ptr->num_text;
    }
 
    if (num_text != NULL)
@@ -980,8 +1047,8 @@ png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr,
 {
    png_debug1(1, "in %s retrieval function", "tIME");
 
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)
-       && mod_time != NULL)
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_tIME) != 0 && mod_time != NULL)
    {
       *mod_time = &(info_ptr->mod_time);
       return (PNG_INFO_tIME);
@@ -997,7 +1064,8 @@ png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
     png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
 {
    png_uint_32 retval = 0;
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
+   if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_tRNS) != 0)
    {
       png_debug1(1, "in %s retrieval function", "tRNS");
 
@@ -1036,9 +1104,9 @@ png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr,
 }
 #endif
 
-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
 int PNGAPI
-png_get_unknown_chunks(png_const_structrp png_ptr, png_const_inforp info_ptr,
+png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr,
     png_unknown_chunkpp unknowns)
 {
    if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
@@ -1070,7 +1138,24 @@ png_get_user_chunk_ptr(png_const_structrp png_ptr)
 png_size_t PNGAPI
 png_get_compression_buffer_size(png_const_structrp png_ptr)
 {
-   return (png_ptr ? png_ptr->zbuf_size : 0);
+   if (png_ptr == NULL)
+      return 0;
+
+#ifdef PNG_WRITE_SUPPORTED
+      if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
+#endif
+   {
+#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
+         return png_ptr->IDAT_read_size;
+#else
+         return PNG_IDAT_READ_SIZE;
+#endif
+   }
+
+#ifdef PNG_WRITE_SUPPORTED
+      else
+         return png_ptr->zbuffer_size;
+#endif
 }
 
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
@@ -1101,7 +1186,7 @@ png_get_chunk_malloc_max (png_const_structrp png_ptr)
 {
    return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
 }
-#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+#endif /* SET_USER_LIMITS */
 
 /* These functions were added to libpng 1.4.0 */
 #ifdef PNG_IO_STATE_SUPPORTED
@@ -1116,15 +1201,19 @@ png_get_io_chunk_type (png_const_structrp png_ptr)
 {
    return png_ptr->chunk_name;
 }
+#endif /* IO_STATE */
 
-#if PNG_LIBPNG_VER < 10600
-png_const_bytep PNGAPI
-png_get_io_chunk_name (png_structrp png_ptr)
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#  ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+int PNGAPI
+png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr)
 {
-   PNG_CSTRING_FROM_CHUNK(png_ptr->io_chunk_string, png_ptr->chunk_name);
-   return png_ptr->io_chunk_string;
-}
-#endif
-#endif /* ?PNG_IO_STATE_SUPPORTED */
+   if (png_ptr != NULL && info_ptr != NULL)
+      return png_ptr->num_palette_max;
 
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+   return (-1);
+}
+#  endif
+#endif
+
+#endif /* READ || WRITE */

pnginfo.h

@@ -1,12 +1,11 @@
 
 /* pnginfo.h - header file for PNG reference library
  *
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
- *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
@@ -55,7 +54,7 @@
 
 struct png_info_def
 {
-   /* the following are necessary for every PNG file */
+   /* The following are necessary for every PNG file */
    png_uint_32 width;  /* width of image in pixels (from IHDR) */
    png_uint_32 height; /* height of image in pixels (from IHDR) */
    png_uint_32 valid;  /* valid chunk data (see PNG_INFO_ below) */
@@ -70,11 +69,17 @@ struct png_info_def
    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
 
-   /* The following is informational only on read, and not used on writes. */
+   /* The following are set by png_set_IHDR, called from the application on
+    * write, but the are never actually used by the write code.
+    */
    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
    png_byte pixel_depth;    /* number of bits per pixel */
    png_byte spare_byte;     /* to align the data, and for future use */
+
+#ifdef PNG_READ_SUPPORTED
+   /* This is never set during write */
    png_byte signature[8];   /* magic bytes read by libpng from start of file */
+#endif
 
    /* The rest of the data is optional.  If you are reading, check the
     * valid field to see if the information in these are valid.  If you
@@ -82,18 +87,25 @@ struct png_info_def
     * and initialize the appropriate fields below.
     */
 
-#if defined(PNG_gAMA_SUPPORTED)
-   /* The gAMA chunk describes the gamma characteristics of the system
-    * on which the image was created, normally in the range [1.0, 2.5].
-    * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
+#if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
+   /* png_colorspace only contains 'flags' if neither GAMMA or COLORSPACE are
+    * defined.  When COLORSPACE is switched on all the colorspace-defining
+    * chunks should be enabled, when GAMMA is switched on all the gamma-defining
+    * chunks should be enabled.  If this is not done it becomes possible to read
+    * inconsistent PNG files and assign a probably incorrect interpretation to
+    * the information.  (In other words, by carefully choosing which chunks to
+    * recognize the system configuration can select an interpretation for PNG
+    * files containing ambiguous data and this will result in inconsistent
+    * behavior between different libpng builds!)
     */
-   png_fixed_point gamma;
+   png_colorspace colorspace;
 #endif
 
-#ifdef PNG_sRGB_SUPPORTED
-    /* GR-P, 0.96a */
-    /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
-   png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
+#ifdef PNG_iCCP_SUPPORTED
+   /* iCCP chunk data. */
+   png_charp iccp_name;     /* profile name */
+   png_bytep iccp_profile;  /* International Color Consortium profile data */
+   png_uint_32 iccp_proflen;  /* ICC profile data length */
 #endif
 
 #ifdef PNG_TEXT_SUPPORTED
@@ -108,7 +120,7 @@ struct png_info_def
    int num_text; /* number of comments read or comments to write */
    int max_text; /* current size of text array */
    png_textp text; /* array of comments read or comments to write */
-#endif /* PNG_TEXT_SUPPORTED */
+#endif /* TEXT */
 
 #ifdef PNG_tIME_SUPPORTED
    /* The tIME chunk holds the last time the displayed image data was
@@ -183,23 +195,6 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
    png_uint_16p hist;
 #endif
 
-#ifdef PNG_cHRM_SUPPORTED
-   /* The cHRM chunk describes the CIE color characteristics of the monitor
-    * on which the PNG was created.  This data allows the viewer to do gamut
-    * mapping of the input image to ensure that the viewer sees the same
-    * colors in the image as the creator.  Values are in the range
-    * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
-    */
-   png_fixed_point x_white;
-   png_fixed_point y_white;
-   png_fixed_point x_red;
-   png_fixed_point y_red;
-   png_fixed_point x_green;
-   png_fixed_point y_green;
-   png_fixed_point x_blue;
-   png_fixed_point y_blue;
-#endif
-
 #ifdef PNG_pCAL_SUPPORTED
    /* The pCAL chunk describes a transformation between the stored pixel
     * values and original physical data values used to create the image.
@@ -224,25 +219,20 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
 /* New members added in libpng-1.0.6 */
    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
- defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
+#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
    /* Storage for unknown chunks that the library doesn't recognize. */
    png_unknown_chunkp unknown_chunks;
-   int unknown_chunks_num;
-#endif
 
-#ifdef PNG_iCCP_SUPPORTED
-   /* iCCP chunk data. */
-   png_charp iccp_name;     /* profile name */
-   png_bytep iccp_profile;  /* International Color Consortium profile data */
-   png_uint_32 iccp_proflen;  /* ICC profile data length */
-   png_byte iccp_compression; /* Always zero */
+   /* The type of this field is limited by the type of 
+    * png_struct::user_chunk_cache_max, else overflow can occur.
+    */
+   int                unknown_chunks_num;
 #endif
 
 #ifdef PNG_sPLT_SUPPORTED
    /* Data on sPLT chunks (there may be more than one). */
    png_sPLT_tp splt_palettes;
-   png_uint_32 splt_palettes_num;
+   int         splt_palettes_num; /* Match type returned by png_get API */
 #endif
 
 #ifdef PNG_sCAL_SUPPORTED

pngmem.c

@@ -1,8 +1,8 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.6.0 [(PENDING RELEASE)]
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.15 [November 20, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -30,7 +30,7 @@ png_destroy_png_struct(png_structrp png_ptr)
        * png_get_mem_ptr, so fake a temporary png_struct to support this.
        */
       png_struct dummy_struct = *png_ptr;
-      memset(png_ptr, 0, sizeof *png_ptr);
+      memset(png_ptr, 0, (sizeof *png_ptr));
       png_free(&dummy_struct, png_ptr);
 
 #     ifdef PNG_SETJMP_SUPPORTED
@@ -41,7 +41,7 @@ png_destroy_png_struct(png_structrp png_ptr)
 }
 
 /* Allocate memory.  For reasonable files, size should never exceed
- * 64K.  However, zlib may allocate more then 64K if you don't tell
+ * 64K.  However, zlib may allocate more than 64K if you don't tell
  * it not to.  See zconf.h and png.h for more information.  zlib does
  * need to allocate exactly 64K, so whatever you call here must
  * have the ability to do that.
@@ -54,7 +54,7 @@ png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
    ret = png_malloc(png_ptr, size);
 
    if (ret != NULL)
-      png_memset(ret, 0, size);
+      memset(ret, 0, size);
 
    return ret;
 }
@@ -73,10 +73,14 @@ png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
     * to implement a user memory handler.  This checks to be sure it isn't
     * called with big numbers.
     */
-#ifdef PNG_USER_MEM_SUPPORTED
+#ifndef PNG_USER_MEM_SUPPORTED
    PNG_UNUSED(png_ptr)
 #endif
-   if (size > 0 && size <= ~(size_t)0
+
+   /* Some compilers complain that this is always true.  However, it
+    * can be false when integer overflow happens.
+    */
+   if (size > 0 && size <= PNG_SIZE_MAX
 #     ifdef PNG_MAX_MALLOC_64K
          && size <= 65536U
 #     endif
@@ -95,6 +99,71 @@ png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
       return NULL;
 }
 
+#if defined(PNG_TEXT_SUPPORTED) || defined(PNG_sPLT_SUPPORTED) ||\
+   defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED)
+/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
+ * that arises because of the checks in png_realloc_array that are repeated in
+ * png_malloc_array.
+ */
+static png_voidp
+png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
+   size_t element_size)
+{
+   png_alloc_size_t req = nelements; /* known to be > 0 */
+
+   if (req <= PNG_SIZE_MAX/element_size)
+      return png_malloc_base(png_ptr, req * element_size);
+
+   /* The failure case when the request is too large */
+   return NULL;
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+   size_t element_size),PNG_ALLOCATED)
+{
+   if (nelements <= 0 || element_size == 0)
+      png_error(png_ptr, "internal error: array alloc");
+
+   return png_malloc_array_checked(png_ptr, nelements, element_size);
+}
+
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
+   int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
+{
+   /* These are internal errors: */
+   if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+      (old_array == NULL && old_elements > 0))
+      png_error(png_ptr, "internal error: array realloc");
+
+   /* Check for overflow on the elements count (so the caller does not have to
+    * check.)
+    */
+   if (add_elements <= INT_MAX - old_elements)
+   {
+      png_voidp new_array = png_malloc_array_checked(png_ptr,
+         old_elements+add_elements, element_size);
+
+      if (new_array != NULL)
+      {
+         /* Because png_malloc_array worked the size calculations below cannot
+          * overflow.
+          */
+         if (old_elements > 0)
+            memcpy(new_array, old_array, element_size*(unsigned)old_elements);
+
+         memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+            element_size*(unsigned)add_elements);
+
+         return new_array;
+      }
+   }
+
+   return NULL; /* error */
+}
+#endif /* TEXT || sPLT || STORE_UNKNOWN_CHUNKS */
+
 /* Various functions that have different error handling are derived from this.
  * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
  * function png_malloc_default is also provided.
@@ -133,7 +202,7 @@ png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
 
    return ret;
 }
-#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* USER_MEM */
 
 /* This function was added at libpng version 1.2.3.  The png_malloc_warn()
  * function will issue a png_warning and return NULL instead of issuing a
@@ -178,7 +247,7 @@ png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
-#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* USER_MEM */
 
    free(ptr);
 }
@@ -211,5 +280,5 @@ png_get_mem_ptr(png_const_structrp png_ptr)
 
    return png_ptr->mem_ptr;
 }
-#endif /* PNG_USER_MEM_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
+#endif /* USER_MEM */
+#endif /* READ || WRITE */