[master] Imported from libpng-1.6.17.tar

[master] Imported from libpng-1.6.16.tar
[master] Imported from libpng-1.6.15.tar
2025-07-10 18:04:09 +02:00 · 2015-03-26 08:11:22 -05:00 · 2015-01-15 12:47:40 -05:00 · 2014-11-20 10:23:30 -06:00 · 2014-10-22 19:33:27 -05:00 · 2014-08-21 05:59:56 -05:00
319 changed files with 82404 additions and 83296 deletions
--- a/129
+++ b/129
@@ -1,5 +1,4 @@
-
-Libpng 1.2.19 - August 18, 2007
+Libpng 1.6.17 - March 26, 2015

 This is a public release of libpng, intended for use in production codes.

@@ -8,94 +7,66 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script

-   libpng-1.2.19.tar.gz
-   libpng-1.2.19.tar.bz2
-
-Source files with LF line endings (for Unix/Linux) without the
-"configure" script
-
-   libpng-1.2.19-no-config.tar.gz
-   libpng-1.2.19-no-config.tar.bz2
+   libpng-1.6.17.tar.xz (LZMA-compressed, recommended)
+   libpng-1.6.17.tar.gz

 Source files with CRLF line endings (for Windows), without the
 "configure" script

-   lpng1219.zip
-   lpng1219.tar.bz2
-
-Project files
-
-   libpng-1.2.19-project-netware.zip
-   libpng-1.2.19-project-wince.zip
+   lpng1617.7z  (LZMA-compressed, recommended)
+   lpng1617.zip

 Other information:

-   libpng-1.2.19-README.txt
-   libpng-1.2.19-KNOWNBUGS.txt
-   libpng-1.2.19-LICENSE.txt
-   libpng-1.2.19-Y2K-compliance.txt
+   libpng-1.6.17-README.txt
+   libpng-1.6.17-LICENSE.txt
+   libpng-1.6.17-*.asc (armored detached GPG signatures)

-Changes since the last public release (1.2.18):
+Changes since the last public release (1.6.16):

-version 1.2.19 [August 18, 2007]
-
-  Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
-    change of libpng-1.2.17beta2.  Changed other "const" to "PNG_CONST"
-  Fixed png_do_expand() to only use the appropriate bits of tRNS value.
-  Fixed png_handle_tRNS() to only use the appropriate bits of tRNS value.
-  Add some "png_byte" typecasts in png_check_keyword().
-  Write new_key instead of key in zTXt chunk.
-  Add png_snprintf() function and use it in place of sprint() for improved
-    defense against buffer overflows.
-  Changed handling of some unused parameters, to avoid compiler warnings.
-  Removed some PNG_CONST in pngwutil.c to avoid compiler warnings.
-  Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c
-  Squelched png_squelch_warnings() in pnggccrd.c; Use "__attribute__((used))"
-    instead.
-  Removed __MMX__ from test in pngconf.h.
-  Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86.
-  Return 0 from png_get_sPLT() and png_get_unknown_chunks() if png_ptr is NULL;
-    changed three remaining instances of png_strcpy() to png_strncpy() (David
-    Hill).
-  Make test for NULL row_buf at the beginning of png_do_read_transformations
-    unconditional.
-  Prefer PNG_USE_PNGVCRD when _MSC_VER is defined in pngconf.h
-  Revised pnggccrd.c.
-  Updated contrib/gregbook.
-  Changed '#include "pnggccrd.c"' to 'include "$srcdir/pnggccrd.c"'
-    in configure.ac
-  Revised many of the makefiles, to set -DPNG_NO_MMX_CODE where needed
-    and to not use -O3 unless -DPNG_NO_MMX_CODE is also set.
-  Copied optimized C code from pnggccrd.c to pngrutil.c, removed dependency
-    on pnggccrd.o from many makefiles.
-  Added sl and dylib to list of extensions be installed by Makefile.am
-  Fixed testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN in pngrtran.c
-  Revised pngvcrd.c.
-  Rebuilt Makefile.in and configure using libtool-1.5.24.
-  Added "test" target to Makefile.in and Makefile.am
-  Added info about pngrutil/pnggccrd/pngvcrd to png_get_header_version()
-  Added PNG_NO_WRITE_FILTER and PNG_NO_WARNING macros.
-  Added contrib/pngminim to demonstrate building minimal encoder and decoder
-  Changed "png_free(str)" to "png_free(png_ptr,str)" in pngrutil.c WinCE
-    code (Yves Piguet).  This bug was introduced in libpng-1.2.14.
-  Updated scripts/CMakeLists.txt
-  Fixed incorrect stride and number of bytes copied (was 4 instead of
-    6 bytes) in the cleanup loop of pnggccrd.c and pngvcrd.c for handling
-    the end of 48-bit interlaced rows (Glenn R-P).
-  Added png_warning() in pngrutil.c for short iCCP, iTXt, sPLT, or zTXT chunks.
-  Revised pngtest.c so warnings are displayed regardless of PNG_NO_STDIO.
-  Disable PNG_MMX_CODE_SUPPORTED when PNG_ASSEMBLER_CODE_SUPPORTED is off.
-  Added information about disabling the MMX code in libpng documentation.
-  Removed some "#if 0" blocks.
-  Made a global struct local in pngvcrd.c to make it thread safe.
-  Change default to PNG_NO_GLOBAL_ARRAYS for MSVC.
-  Revise handling of png_strtod in recent versions of WINCE
-  Issue a png_error() if application attempts to transform a row tht
-    has not been initialized.
+  Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
+  Corrected the width limit calculation in png_check_IHDR().
+  Removed user limits from pngfix. Also pass NULL pointers to
+    png_read_row to skip the unnecessary row de-interlace stuff.
+  Added testing of png_set_packing() to pngvalid.c
+  Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
+  Implement previously untested cases of libpng transforms in pngvalid.c
+  Fixed byte order in 2-byte filler, in png_do_read_filler().
+  Made the check for out-of-range values in png_set_tRNS() detect
+    values that are exactly 2^bit_depth, and work on 16-bit platforms.
+  Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47.
+  Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
+    pngset.c to avoid warnings about dead code.
+  Do not build png_product2() when it is unused.
+  Display user limits in the output from pngtest.
+  Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column
+    and 1-million-row default limits in pnglibconf.dfa, that can be reset
+    by the user at build time or run time.  This provides a more robust
+    defense against DOS and as-yet undiscovered overflows.
+  Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
+  Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
+  Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
+  Moved png_set_filter() prototype into a PNG_WRITE_SUPPORTED block
+    of png.h.
+  Avoid runtime checks when converting integer to png_byte with
+    Visual Studio (Sergey Kosarevsky)
+  Removed some comments that the configure script did not handle
+    properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt.
+  Free the unknown_chunks structure even when it contains no data.
+  Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF
+    for consistency, and remove some useless tests (Alexey Petruchik).
+  Remove pnglibconf.h, pnglibconf.c, pnglibconf.pre, pnglibconf.dfn,
+    and pnglibconf.out instead of pnglibconf.* in "make clean" (Cosmin).
+  Fixed simplified 8-bit-linear to sRGB alpha. The calculated alpha
+    value was wrong.  It's not clear if this affected the final stored
+    value; in the obvious code path the upper and lower 8-bits of the
+    alpha value were identical and the alpha was truncated to 8-bits
+    rather than dividing by 257 (John Bowler).

 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-(subscription required; visit 
+(subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe) or to glennrp at users.sourceforge.net
+to subscribe)
+or to glennrp at users.sourceforge.net

 Glenn R-P
--- a/4396
+++ b/4396
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -0,0 +1,374 @@
+# CMakeLists.txt
+
+# Copyright (C) 2007-2015 Glenn Randers-Pehrson
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+cmake_minimum_required(VERSION 2.4.4)
+set(CMAKE_ALLOW_LOOSE_LOOP_CONSTRUCTS true)
+
+set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
+
+project(libpng C)
+enable_testing()
+
+set(PNGLIB_MAJOR 1)
+set(PNGLIB_MINOR 6)
+set(PNGLIB_RELEASE 17)
+set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
+set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
+
+# needed packages
+find_package(ZLIB REQUIRED)
+include_directories(${ZLIB_INCLUDE_DIR})
+
+if(NOT WIN32)
+  find_library(M_LIBRARY
+    NAMES m
+    PATHS /usr/lib /usr/local/lib
+  )
+  if(NOT M_LIBRARY)
+    message(STATUS "math lib 'libm' not found; floating point support disabled")
+  endif()
+else()
+  # not needed on windows
+  set(M_LIBRARY "")
+endif()
+
+# COMMAND LINE OPTIONS
+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_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})
+
+# to distinguish between debug and release lib
+set(CMAKE_DEBUG_POSTFIX "d")
+
+# Use the prebuilt pnglibconf.h file from the scripts folder
+# TODO: fix this by building with awk; without this no cmake build can be
+# configured directly (to do so indirectly use your local awk to build a
+# pnglibconf.h in the build directory.)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt
+               ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h)
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+# OUR SOURCES
+set(libpng_public_hdrs
+  png.h
+  pngconf.h
+  ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h
+)
+set(libpng_sources
+  ${libpng_public_hdrs}
+  pngdebug.h
+  pnginfo.h
+  pngpriv.h
+  pngstruct.h
+  png.c
+  pngerror.c
+  pngget.c
+  pngmem.c
+  pngpread.c
+  pngread.c
+  pngrio.c
+  pngrtran.c
+  pngrutil.c
+  pngset.c
+  pngtrans.c
+  pngwio.c
+  pngwrite.c
+  pngwtran.c
+  pngwutil.c
+)
+set(pngtest_sources
+  pngtest.c
+)
+set(pngvalid_sources
+  contrib/libtests/pngvalid.c
+)
+set(pngstest_sources
+  contrib/libtests/pngstest.c
+)
+# SOME NEEDED DEFINITIONS
+
+if(MSVC)
+  add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+endif(MSVC)
+
+if(PNG_DEBUG)
+  add_definitions(-DPNG_DEBUG)
+endif()
+
+# NOW BUILD OUR TARGET
+include_directories(${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")
+    set_target_properties(${PNG_LIB_NAME} PROPERTIES IMPORT_PREFIX "lib")
+  endif()
+  target_link_libraries(${PNG_LIB_NAME} ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
+if(PNG_STATIC)
+  # 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")
+  endif()
+  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()
+
+if(PNG_TESTS AND PNG_SHARED)
+  # does not work with msvc due to png_lib_ver issue
+  add_executable(pngtest ${pngtest_sources})
+  target_link_libraries(pngtest ${PNG_LIB_NAME})
+  add_test(pngtest ./pngtest ${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png)
+  #
+  add_executable(pngvalid ${pngvalid_sources})
+  target_link_libraries(pngvalid ${PNG_LIB_NAME})
+  add_test(pngvalid ./pngvalid)
+  add_executable(pngstest ${pngstest_sources})
+  target_link_libraries(pngstest ${PNG_LIB_NAME})
+  add_test(pngstest ./pngstest
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g01.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g02.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g04.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn0g16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn2c08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn2c16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn3p01.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn3p02.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn3p04.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn4a08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn4a16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn6a08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/basn6a16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g01.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g02.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn0g04.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn2c16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbbn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbgn2c16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbgn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbrn2c08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbwn0g16.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbwn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftbyn3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n0g08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n2c08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp0n3p08.png
+    ${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/ftp1n3p08.png
+  )
+endif()
+
+# Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set
+IF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+  SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
+ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+
+# Set a variable with CMake code which:
+# Creates a symlink from src to dest (if possible) or alternatively
+# copies if different.
+macro(CREATE_SYMLINK SRC_FILE DEST_FILE)
+  FILE(REMOVE ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  if(WIN32 AND NOT CYGWIN AND NOT MSYS)
+    ADD_CUSTOM_COMMAND(
+        OUTPUT ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}   ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        DEPENDS ${PNG_LIB_TARGETS}
+        )
+    ADD_CUSTOM_TARGET(${DEST_FILE}_COPY ALL DEPENDS ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  else(WIN32 AND NOT CYGWIN AND NOT MSYS)
+    get_filename_component(LINK_TARGET "${SRC_FILE}" NAME)
+    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_LIBRARY_OUTPUT_DIRECTORY})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+  endif(WIN32 AND NOT CYGWIN AND NOT MSYS)
+endmacro()
+
+# libpng is a library so default to 'lib'
+if(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+  set(CMAKE_INSTALL_LIBDIR lib)
+endif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+
+# CREATE PKGCONFIG FILES
+# 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(${PNGLIB_NAME}.pc libpng.pc)
+
+  configure_file(${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.${PNGLIB_RELEASE}.1.6.17
+    VERSION 16.${PNGLIB_RELEASE}.0
+    SOVERSION 16
+    CLEAN_DIRECT_OUTPUT 1)
+endif()
+if(PNG_STATIC)
+  # MSVC doesn't use a different file extension for shared vs. static
+  # libs.  We are able to change OUTPUT_NAME to remove the _static
+  # for all other platforms.
+  if(NOT MSVC)
+    set_target_properties(${PNG_LIB_NAME_STATIC} PROPERTIES
+      OUTPUT_NAME ${PNG_LIB_NAME}
+      CLEAN_DIRECT_OUTPUT 1)
+  endif()
+endif()
+
+# If CMake > 2.4.x, we set a variable used below to export
+# targets to an export file.
+# TODO: Use VERSION_GREATER after our cmake_minimum_required >= 2.6.2
+if(CMAKE_MAJOR_VERSION GREATER 1 AND CMAKE_MINOR_VERSION GREATER 4)
+  set(PNG_EXPORT_RULE EXPORT libpng)
+elseif(CMAKE_MAJOR_VERSION GREATER 2) # future proof
+  set(PNG_EXPORT_RULE EXPORT libpng)
+endif()
+
+# INSTALL
+if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
+  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})
+       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})
+      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32)
+  endif(PNG_SHARED)
+
+  if(PNG_STATIC)
+    if(NOT WIN32 OR CYGWIN OR MINGW)
+      get_target_property(BUILD_TARGET_LOCATION ${PNG_LIB_NAME_STATIC} LOCATION_${CMAKE_BUILD_TYPE})
+      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32 OR CYGWIN OR MINGW)
+ endif()
+endif()
+
+if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
+  install(FILES ${libpng_public_hdrs}   DESTINATION include)
+  install(FILES ${libpng_public_hdrs}   DESTINATION include/${PNGLIB_NAME})
+endif()
+if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL )
+  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)
+    set(PNG_MAN_DIR "share/man")
+  endif()
+  install(FILES libpng.3 libpngpf.3      DESTINATION ${PNG_MAN_DIR}/man3)
+  install(FILES png.5                    DESTINATION ${PNG_MAN_DIR}/man5)
+  # Install pkg-config files
+  if(NOT 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
+# users can include() to import our targets
+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-manual.txt and all the extra files?
+
+# UNINSTALL
+# do we need this?
+
+# DIST
+# do we need this?
+
+# to create msvc import lib for mingw compiled shared lib
+# pexports libpng.dll > libpng.def
+# lib /def:libpng.def /machine:x86
+
--- a/447
+++ b/447
@@ -1,5 +1,26 @@

-Installing libpng version 1.2.19 - August 18, 2007
+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

@@ -7,45 +28,91 @@ On Unix/Linux and similar systems, you can simply type
    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.  If you run 'libtoolize --force', though, this will replace
-the distributed, patched, version of ltmain.sh with an unpatched version
-and your shared library builds may fail to produce libraries with the
-correct version numbers.
+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 --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

+The files that are presently available in the scripts directory
+are listed and described in scripts/README.txt.
+
 Or you can use one of the "projects" in the "projects" directory.

-If you want to use "cmake" (see www.cmake.org), copy CMakeLists.txt
-from the "scripts" directory to this directory and type
-
-   cmake . [-DPNG_MMX=YES] -DCMAKE_INSTALL_PREFIX=/path
-   make
-   make install
-
 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
+
+   cmake . -DCMAKE_INSTALL_PREFIX=/path
+   make
+   make install
+
+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-1.2.19" or "lpng109" and "zlib-1.2.1"
-or "zlib121") 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:

@@ -53,128 +120,55 @@ 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,
+             autogen.sh, config.guess, ltmain.sh, missing, libpng.pc.in,
+             libpng-config.in, aclocal.m4, config.h.in, config.sub,
+             depcomp, install-sh, mkinstalldirs, test-pngtest.sh
          contrib
-             gregbook
-             pngminus
-             pngsuite
-             visupng
+             arm-neon, conftest, examples, gregbook, libtests, pngminim,
+             pngminus, pngsuite, tools, visupng
          projects
-             beos
-             c5builder (Borland)
-             visualc6 (msvc)
-             netware.txt
-             wince.txt
+             cbuilder5, owatcom, visualc71, vstudio, xcode
          scripts
             makefile.*
+             *.def (module definition files)
+             etc.
          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 directory and follow the instructions in
-projects\visualc6\README.txt.
+libpng projects\visualc71 or vstudio directory and follow the instructions
+in README.txt.

-You can build libpng for WindowsCE by downloading and installing
-the projects\wince directory as instructed in the projects\wince.txt file, and
-then following the instructions in the README* files.  Similarly, you can
-build libpng for Netware or Beos as instructed in projects\netware.txt
-or projects\beos.
-
-Else enter the zlib directory and follow the instructions in zlib/README,
+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.

-The files that are presently available in the scripts directory
-include
-
- CMakeLists.txt    =>  "cmake" script
- makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
- makefile.elf      =>  Linux/ELF makefile symbol versioning,
-                       gcc, creates libpng12.so.0.1.2.19)
- makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng12.so.0.1.2.19)
- makefile.gcmmx    =>  Linux/ELF makefile
-                       (gcc, creates libpng12.so.0.1.2.19,
-                       uses assembler code tuned for Intel MMX platform)
- makefile.nommx    =>  Linux/ELF makefile
-                       (gcc, creates libpng12.so.0.1.2.19
-                       does not use Intel MMX assembler code)
- makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
- makefile.knr      =>  Archaic UNIX Makefile that converts files with
-                       ansi2knr (Requires ansi2knr.c from
-                       ftp://ftp.cs.wisc.edu/ghost)
- makefile.aix      =>  AIX/gcc makefile
- makefile.cygwin   =>  Cygwin/gcc makefile
- makefile.darwin   =>  Darwin makefile, can use on MacosX
- makefile.dec      =>  DEC Alpha UNIX makefile
- makefile.freebsd  =>  FreeBSD makefile
- makefile.hpgcc    =>  HPUX makefile using gcc
- makefile.hpux     =>  HPUX (10.20 and 11.00) makefile
- makefile.hp64     =>  HPUX (10.20 and 11.00) makefile, 64-bit
- makefile.ibmc     =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
- makefile.intel    =>  Intel C/C++ version 4.0 and later
- libpng.icc        =>  Project file for IBM VisualAge/C++ version 4.0 or later
- makefile.netbsd   =>  NetBSD/cc makefile, uses PNGGCCRD, makes libpng.so.
- makefile.ne12bsd  =>  NetBSD/cc makefile, uses PNGGCCRD,
-                       makes libpng12.so
- makefile.openbsd  =>  OpenBSD makefile
- makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
- makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng12.so.0.1.2.19)
- makefile.sunos    =>  Sun makefile
- makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng12.so.0.1.2.19)
- makefile.solaris-x86 =>  Solaris/intelMMX 2.X makefile (gcc,
-                       creates libpng12.so.0.1.2.19)
- makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng12.so.0.1.2.19)
- makefile.32sunu   =>  Sun Ultra 32-bit makefile
- makefile.64sunu   =>  Sun Ultra 64-bit makefile
- makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
- makefile.mips     =>  MIPS makefile
- makefile.acorn    =>  Acorn makefile
- makefile.amiga    =>  Amiga makefile
- smakefile.ppc     =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
-                       (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
- makefile.atari    =>  Atari makefile
- makefile.beos     =>  BEOS makefile for X86
- makefile.bor      =>  Borland makefile (uses bcc)
- makefile.bc32     =>  32-bit Borland C++ (all modules compiled in C mode)
- makefile.tc3      =>  Turbo C 3.0 makefile
- makefile.dj2      =>  DJGPP 2 makefile
- makefile.msc      =>  Microsoft C makefile
- makefile.vcawin32 =>  makefile for Microsoft Visual C++ 5.0 and later (uses
-                       assembler code tuned for Intel MMX platform)
- makefile.vcwin32  =>  makefile for Microsoft Visual C++ 4.0 and later (does
-                       not use assembler code)
- makefile.os2      =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
- pngos2.def        =>  OS/2 module definition file used by makefile.os2
- makefile.watcom   =>  Watcom 10a+ Makefile, 32-bit flat memory model
- makevms.com       =>  VMS build script
- descrip.mms       =>  VMS makefile for MMS or MMK
- SCOPTIONS.ppc     =>  Used with smakefile.ppc
+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.

-Then read pngconf.h to see if you want to make any configuration
+Then read pnglibconf.dfa to see if you want to make any configuration
 changes.

 Then just run "make" which will create the libpng library in
@@ -192,37 +186,222 @@ 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".

-If you encounter a compiler error message complaining about the
-lines
-      __png.h__ already includes setjmp.h;
-      __dont__ include it again.;
-This means you have compiled another module that includes setjmp.h,
-which is hazardous because the two modules might not include exactly
-the same setjmp.h.  If you are sure that you know what you are doing
-and that they are exactly the same, then you can comment out or
-delete the two lines.  Better yet, use the cexcept interface
-instead, as demonstrated in contrib/visupng of the libpng distribution.
+VIII. Configuring libpng for 16-bit platforms

-Further information can be found in the README and libpng.txt
+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.

-
 Using the ./configure script -- 16 December 2002.
 =================================================

-
 The ./configure script should work compatibly with what scripts/makefile.*
-did, however there are some options you need to add to configure explicitly,
-which previously was done semi-automatically (if you didn't edit
+did, however there are some options you might need to add to configure
+explicitly, which previously was done semi-automatically (if you didn't edit
 scripts/makefile.* yourself, that is)

-
 CFLAGS="-Wall -O -funroll-loops \
 -malign-loops=2 -malign-functions=2" ./configure --prefix=/usr/include \
 --with-pkgconfigdir=/usr/lib/pkgconfig --includedir=/usr/include

 You can alternatively specify --includedir=/usr/include, /usr/local/include,
-/usr/include/png12, 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",
+"Makefile.in", and the other configuration files. Then try configure again.

--- a/29
+++ b/29
@@ -1,29 +0,0 @@
-
-Known bugs in libpng version 1.2.19
-
-1. April 22, 2001: pnggccrd.c has been reported to crash on NetBSD when
-   reading interlaced PNG files, when assembler code is enabled but running
-   on a non-MMX i386 platform.
-
-   STATUS: Under investigation.  The change to pnggccrd.c in libpng-1.2.1
-   fixed a problem under FreeBSD but not the problem with NetBSD, which
-   still fails as of libpng-1.2.2rc1.
-
-2. February 23, 2006: The custom makefiles don't build libpng with -lz.
-
-   STATUS: This is a subject of debate. The change will probably be made
-   as a part of a major overhaul of the makefiles in libpng version 1.3.0.
-
-3. February 24, 2006: The Makefile generated by the "configure" script
-   fails to install symbolic links
-   libpng12.so => libpng12.so.0.1.2.9betaN
-   that are generated by the custom makefiles.
-
-4. June 28, 2007: Pnggccrd.c has been reported to be unreliable on
-   several 64-bit platforms running gcc-3.x.  Although it appears to
-   build properly, it does not always read files correctly.
-
-   STATUS:  Appears to be a bug in the 64-bit version of gcc-3.4.6.
-   Workarounds are to define PNG_NO_MMX_FILTER_UP|AVG|PAETH (as in
-   pngconf.h) or to upgrade gcc to a newer version.
-
--- a/8
+++ b/8
@@ -8,8 +8,10 @@ COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
 If you modify libpng you may insert additional notices immediately following
 this sentence.

-libpng versions 1.2.6, August 15, 2004, through 1.2.19, August 18, 2007, are
-Copyright (c) 2004, 2006-2007 Glenn Randers-Pehrson, and are
+This code is released under the libpng license.
+
+libpng versions 1.2.6, August 15, 2004, through 1.6.17, March 26, 2015, are
+Copyright (c) 2004, 2006-2015 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

@@ -106,4 +108,4 @@ certification mark of the Open Source Initiative.

 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-August 18, 2007
+March 26, 2015
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,92 +1,159 @@
 # Makefile.am:
 #   Source file for Makefile.in (and hence Makefile)
 #
-# Makefile.am need only be changed on a major version number
-# change (e.g. libpng12 --> libpng13).  In that case seach
-# this file for every instance of the old base name (libpng12)
-# and change to the new one (libpng13), then change the
-# -version-number settings below so that the new values have
-# the correct major part (first field).

 PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@

-# libpng does not follow GNU file name conventions
-AUTOMAKE_OPTIONS = foreign
+ACLOCAL_AMFLAGS = -I scripts

 # test programs - run on make check, make distcheck
-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 = libpng12.la
-TESTS = test-pngtest.sh
-TESTS_ENVIRONMENT= srcdir=$(srcdir) 
+pngtest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngvalid_SOURCES = contrib/libtests/pngvalid.c
+pngvalid_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngstest_SOURCES = contrib/libtests/pngstest.c
+pngstest_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+pngunknown_SOURCES = contrib/libtests/pngunknown.c
+pngunknown_LDADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+
+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

 # generate the -config scripts if required
-binconfigs= libpng12-config 
-EXTRA_SCRIPTS= libpng-config libpng12-config
+binconfigs= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
+EXTRA_SCRIPTS= libpng-config libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@-config
 bin_SCRIPTS= @binconfigs@

 # rules to build libpng, only build the old library on request
-lib_LTLIBRARIES=libpng12.la @compatlib@
-EXTRA_LTLIBRARIES= libpng.la
-libpng12_la_SOURCES = png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
-	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
-	pngwtran.c pngmem.c pngerror.c pngpread.c pnggccrd.c \
-	png.h pngconf.h
-libpng_la_SOURCES = $(libpng12_la_SOURCES)
+lib_LTLIBRARIES=libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
+# EXTRA_LTLIBRARIES= libpng.la
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
+	pngget.c pngmem.c pngpread.c pngread.c pngrio.c pngrtran.c pngrutil.c\
+	pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c\
+	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa

-libpng_la_CPPFLAGS = @LIBPNG_DEFINES@
-libpng12_la_CPPFLAGS = @LIBPNG_DEFINES@
+if PNG_ARM_NEON
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
+	arm/filter_neon.S arm/filter_neon_intrinsics.c
+endif

-# MAJOR UPGRADE: the version-number settings below must be changed.
-libpng12_la_LDFLAGS = -no-undefined -export-dynamic \
-	-version-number 0:@PNGLIB_RELEASE@:0
-# -rpath is needed as automake doesn't know the directory
-libpng_la_LDFLAGS = -rpath '$(libdir)' -no-undefined -export-dynamic \
-	-version-number 3:@PNGLIB_RELEASE@:0
+nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
+
+libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \
+	-version-number @PNGLIB_MAJOR@@PNGLIB_MINOR@:@PNGLIB_RELEASE@:0

 if HAVE_LD_VERSION_SCRIPT
-  # Versioned symbols and restricted exports
-  libpng12_la_LDFLAGS += -Wl,--version-script=libpng.vers
-  libpng12_la_DEPENDENCIES = libpng.vers
+#   Versioned symbols and restricted exports
+if HAVE_SOLARIS_LD
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -Wl,-M -Wl,libpng.vers
 else
-  # Only restricted exports when possible
-  libpng12_la_LDFLAGS += -export-symbols libpng.sym
-  libpng12_la_DEPENDENCIES = libpng.sym
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -Wl,--version-script=libpng.vers
+endif
+
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.vers
+else
+#   Only restricted exports when possible
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS += -export-symbols libpng.sym
+  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.sym
 endif
-libpng_la_DEPENDENCIES = $(libpng12_la_DEPENDENCIES)

 #distribute headers in /usr/include/libpng/*
 pkgincludedir= $(includedir)/$(PNGLIB_BASENAME)
 pkginclude_HEADERS= png.h pngconf.h
+nodist_pkginclude_HEADERS= pnglibconf.h

 # pkg-config stuff, note that libpng.pc is always required in order
 # to get the correct library
 pkgconfigdir = @pkgconfigdir@
-pkgconfig_DATA = libpng12.pc
+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 KNOWNBUG LICENSE README TODO Y2KINFO \
+	ANNOUNCE CHANGES INSTALL LICENSE README TODO \
 	pngtest.png pngbar.png pngnow.png pngbar.jpg autogen.sh \
-	${srcdir}/projects/cbuilder5/* \
-	${srcdir}/projects/beos/* \
-	${srcdir}/projects/visualc6/* \
-	${srcdir}/projects/visualc71/* \
-	${srcdir}/projects/wince.txt \
-	${srcdir}/projects/netware.txt \
-	${srcdir}/scripts/* \
-	${srcdir}/contrib/gregbook/* \
-	${srcdir}/contrib/pngminus/* \
-	${srcdir}/contrib/pngsuite/* \
-	${srcdir}/contrib/visupng/* \
-	$(TESTS) \
-	example.c libpng.txt pngvcrd.c 
+	${srcdir}/contrib ${srcdir}/projects ${srcdir}/scripts \
+	$(TESTS) $(XFAIL_TESTS) tests/pngstest \
+	CMakeLists.txt example.c libpng-manual.txt

-CLEANFILES= pngout.png libpng12.pc libpng12-config libpng.vers \
-libpng.sym
+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.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
+# parsing - and therefore fails with the .df files.  configure.ac has special
+# checks for this and sets DFNCPP appropriately.
+DFNCPP = @DFNCPP@
+
+SUFFIXES = .chk .out

 $(PNGLIB_BASENAME).pc: libpng.pc
 	cp libpng.pc $@
@@ -94,52 +161,207 @@ $(PNGLIB_BASENAME).pc: libpng.pc
 $(PNGLIB_BASENAME)-config: libpng-config
 	cp libpng-config $@

-libpng.sym: png.h pngconf.h
-	rm -f $@ $@.new
-	$(CPP) @LIBPNG_DEFINES@ $(CPPFLAGS) -DPNG_BUILDSYMS $(srcdir)/png.h | \
-		$(SED) -n -e 's|^.*PNG_FUNCTION_EXPORT[ 	]*\([a-zA-Z0-9_]*\).*$$|\1|p' \
-			-e 's|^.*PNG_DATA_EXPORT[ 	]*\([a-zA-Z0-9_]*\).*$$|\1|p' \
-			>$@.new
-	mv $@.new $@
+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.vers: libpng.sym
-	rm -f $@ $@.new
-	$(ECHO) PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0 '{global:' > $@.new
-	$(SED) s/$$/\;/ libpng.sym >> $@.new
-	$(ECHO) 'local: *; };' >> $@.new
-	mv $@.new $@
+libpng.sym: scripts/sym.out
+	rm -f $@
+	cp $? $@
+libpng.vers: scripts/vers.out
+	rm -f $@
+	cp $? $@

-test: check
+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 $@

-# install the .../include headers as links to the new ones
-install-data-hook:
-	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/png.h png.h
-	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/pngconf.h pngconf.h
-	cd $(DESTDIR)$(pkgconfigdir); rm -f libpng.pc
-	cd $(DESTDIR)$(pkgconfigdir); $(LN_S) $(PNGLIB_BASENAME).pc libpng.pc
+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 $? $@

-# do evil things to libpng to cause libpng12 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 sl dylib; do\
-		rm -f libpng.$$ext;\
-                if test -f $(PNGLIB_BASENAME).$$ext; then\
-                       $(LN_S) $(PNGLIB_BASENAME).$$ext libpng.$$ext;\
-                fi;\
+pngprefix.h: # is empty
+	:>$@
+endif
+
+$(srcdir)/scripts/pnglibconf.h.prebuilt:
+	@echo "Attempting to build $@" >&2
+	@echo "This is a machine generated file, but if you want to make" >&2
+	@echo "a new one simply make 'scripts/pnglibconf.out', copy that" >&2
+	@echo "AND set PNG_ZLIB_VERNUM to 0 (you MUST do this)" >&2
+	@exit 1
+
+# The following is necessary to ensure that the local pnglibconf.h is used, not
+# an installed one (this can happen immediately after on a clean system if
+# 'make test' is the first thing the user does.)  Only files which include
+# one of the png source files (typically png.h or pngpriv.h) need to be listed
+# here:
+pngtest.o: pnglibconf.h
+
+contrib/libtests/makepng.o: pnglibconf.h
+contrib/libtests/pngstest.o: pnglibconf.h
+contrib/libtests/pngunknown.o: pnglibconf.h
+contrib/libtests/pngimage.o: pnglibconf.h
+contrib/libtests/pngvalid.o: pnglibconf.h
+contrib/libtests/readpng.o: pnglibconf.h
+contrib/libtests/tarith.o: pnglibconf.h
+contrib/libtests/timepng.o: pnglibconf.h
+
+contrib/tools/makesRGB.o: pnglibconf.h
+contrib/tools/pngfix.o: pnglibconf.h
+
+# We must use -DPNG_NO_USE_READ_MACROS here even when the library may actually
+# be built with PNG_USE_READ_MACROS; this prevents the read macros from
+# interfering with the symbol file format.
+SYMBOL_CFLAGS = -DPNGLIB_LIBNAME='PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0'\
+		-DPNGLIB_VERSION='@PNGLIB_VERSION@'\
+		-DSYMBOL_PREFIX='$(SYMBOL_PREFIX)'\
+		-DPNG_NO_USE_READ_MACROS -DPNG_BUILDING_SYMBOL_TABLE
+
+if DO_PNG_PREFIX
+SYMBOL_CFLAGS += -DPNG_PREFIX='@PNG_PREFIX@'
+endif
+
+.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\
+	    ${srcdir}/pngusr.dfa $(DFA_XTRA) 1>&2
+	$(AWK) -f ${srcdir}/scripts/options.awk out=$*.tf5 $*.tf4 1>&2
+	rm $*.tf4
+	mv $*.tf5 $@
+
+# Symbol checks (.def and .out files should match)
+scripts/symbols.chk: scripts/checksym.awk scripts/symbols.def scripts/symbols.out
+
+.out.chk:
+	rm -f $@ $*.new
+	$(AWK) -f ${srcdir}/scripts/checksym.awk ${srcdir}/scripts/${*F}.def\
+	    of="$*.new" $< >&2
+	mv $*.new $@
+
+# used on demand to regenerate the standard header, CPPFLAGS should
+# be empty - no non-standard defines
+scripts/pnglibconf.c: scripts/pnglibconf.dfa scripts/options.awk pngconf.h
+	rm -f $@ pnglibconf.tf[67]
+	test -z "$(CPPFLAGS)"
+	echo "com @PNGLIB_VERSION@ STANDARD API DEFINITION" |\
+	$(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf6\
+	    logunsupported=1 version=search ${srcdir}/pngconf.h -\
+	    ${srcdir}/scripts/pnglibconf.dfa 1>&2
+	$(AWK) -f ${srcdir}/scripts/options.awk out=pnglibconf.tf7\
+	    pnglibconf.tf6 1>&2
+	rm pnglibconf.tf6
+	mv pnglibconf.tf7 $@
+
+$(libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_OBJECTS): png.h pngconf.h \
+	pnglibconf.h pngpriv.h pngdebug.h pnginfo.h pngstruct.h pngprefix.h
+
+test: check-am
+
+# Extra checks
+check: scripts/symbols.chk
+
+# Don't distribute the generated script files
+dist-hook:
+	cd '$(top_distdir)'; rm -f $(SCRIPT_CLEANFILES)
+
+# Make links between installed files with release-specific names and the generic
+# file names.  If this install rule is run the generic names will be deleted and
+# recreated - this has obvious issues for systems with multiple installations.
+
+install-header-links:
+	@set -ex; cd '$(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
-	rm -f $(DESTDIR)$(pkgconfigdir)/libpng.pc
-	rm -f $(DESTDIR)$(bindir)/libpng-config
-	@if test -n "@compatlib@"; then\
-		set -x;\
-		cd $(DESTDIR)$(libdir);\
-		for ext in a la so sl dylib; do\
-			rm -f libpng.$$ext;\
-		done;\
-	fi
+uninstall-library-links:
+	@set -x; cd '$(DESTDIR)$(libdir)'; for ext in $(EXT_LIST); do\
+	   rm -f "libpng.$$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)
--- a/Makefile.in
+++ b/Makefile.in
--- a/178
+++ b/178
@@ -1,11 +1,11 @@
-README for libpng version 1.2.19 - August 18, 2007 (shared library 12.0)
+README for libpng version 1.6.17 - March 26, 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
-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
@@ -54,11 +61,11 @@ to set different actions based on whether the CRC error occurred in a
 critical or an ancillary chunk.

 The changes made to the library, and bugs fixed are based on discussions
-on the PNG-implement mailing list
-and not on material submitted privately to Guy, Andreas, or Glenn.  They will
-forward any good suggestions to the list.
+on the PNG-implement mailing list and not on material submitted
+privately to Guy, Andreas, or Glenn.  They will forward any good
+suggestions to the list.

-For a detailed description on using libpng, read libpng.txt.  For
+For a detailed description on using libpng, read libpng-manual.txt.  For
 examples of libpng in a program, see example.c and pngtest.c.  For usage
 information and restrictions (what little they are) on libpng, see
 png.h.  For a description on using zlib (the compression library used by
@@ -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,
@@ -101,31 +112,29 @@ Finally, if you get any warning messages when compiling libpng
 fix.  Please mention "libpng" somewhere in the subject line.  Thanks.

 This release was created and will be supported by myself (of course
-based in a large way on Guy's and Andreas' earlier work), and the PNG group.
+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.sf.net
-(subscription required; visit 
+Send comments/corrections/commendations to png-mng-implement at
+lists.sourceforge.net (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
 to subscribe) or to glennrp at users.sourceforge.net

 You can't reach Guy, the original libpng author, at the addresses
-given in previous versions of this document.  He and Andreas will read mail
-addressed to the png-implement list, however.
+given in previous versions of this document.  He and Andreas will
+read mail addressed to the png-implement list, however.

 Please do not send general questions about PNG.  Send them to
-the (png-list at ccrc.wustl.edu, subscription required, write to
-majordomo at ccrc.wustl.edu with "subscribe png-list" in your message).
-On the other hand,
-please do not send libpng questions to that address, send them to me
-or to the png-implement list.  I'll
-get them in the end anyway.  If you have a question about something
+png-mng-misc at lists.sf.net (subscription required; visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
+subscribe).  If you have a question about something
 in the PNG specification that is related to using libpng, send it
 to me.  Send me any questions that start with "I was using libpng,
 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 nine years now, and it is official and
+been discussing PNG for nineteen 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.
@@ -140,14 +149,17 @@ Files in this distribution:
      TODO          =>  Things not implemented in the current library
      Y2KINFO       =>  Statement of Y2K compliance
      example.c     =>  Example code for using libpng functions
-      libpng.3      =>  manual page for libpng (includes libpng.txt)
-      libpng.txt    =>  Description of libpng and its functions
+      libpng.3      =>  manual page for libpng (includes libpng-manual.txt)
+      libpng-manual.txt  =>  Description of libpng and its functions
      libpngpf.3    =>  manual page for libpng's private functions
      png.5         =>  manual page for the PNG format
      png.c         =>  Basic interface functions common to library
-      png.h         =>  Library function and interface declarations
-      pngconf.h     =>  System specific library configuration
-      pngasmrd.h    =>  Header file for assembler-coded functions
+      png.h         =>  Library function and interface declarations (public)
+      pngpriv.h     =>  Library function and interface declarations (private)
+      pngconf.h     =>  System specific library configuration (public)
+      pngstruct.h   =>  png_struct declaration (private)
+      pnginfo.h     =>  png_info struct declaration (private)
+      pngdebug.h    =>  debugging macros (private)
      pngerror.c    =>  Error/warning message I/O functions
      pngget.c      =>  Functions for retrieving info from struct
      pngmem.c      =>  Memory handling functions
@@ -166,92 +178,32 @@ 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
-      projects      =>  Contains project files and workspaces for building DLL
-       beos             =>  Contains a Beos workspace for building libpng
-       c5builder        =>  Contains a Borland workspace for building libpng
-                            and zlib
-       visualc6         =>  Contains a Microsoft Visual C++ (MSVC) workspace
-                            for building libpng and zlib
-       netware.txt      =>  Contains instructions for downloading a set of
-                            project files for building libpng and zlib on
-                            Netware.
-       wince.txt        =>  Contains instructions for downloading a Microsoft
-                            Visual C++ (Windows CD Toolkit) workspace for
-                            building libpng and zlib on WindowsCE
+       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
+       owatcom          =>  Contains a WATCOM project for building libpng
+       visualc71        =>  Contains a Microsoft Visual C++ (MSVC)
+                            workspace for building libpng and zlib
+       vstudio          =>  Contains a Microsoft Visual C++ (MSVC)
+                            workspace for building libpng and zlib
      scripts       =>  Directory containing scripts for building libpng:
-       descrip.mms      =>  VMS makefile for MMS or MMK
-       makefile.std     =>  Generic UNIX makefile (cc, creates static libpng.a)
-       makefile.elf     =>  Linux/ELF makefile symbol versioning,
-                            gcc, creates libpng12.so.0.1.2.19)
-       makefile.linux   =>  Linux/ELF makefile
-                            (gcc, creates libpng12.so.0.1.2.19)
-       makefile.gcmmx   =>  Linux/ELF makefile
-                            (gcc, creates libpng12.so.0.1.2.19,
-                            uses assembler code tuned for Intel MMX platform)
-       makefile.gcc     =>  Generic makefile (gcc, creates static libpng.a)
-       makefile.knr     =>  Archaic UNIX Makefile that converts files with
-                            ansi2knr (Requires ansi2knr.c from
-                            ftp://ftp.cs.wisc.edu/ghost)
-       makefile.aix     =>  AIX makefile
-       makefile.cygwin  =>  Cygwin/gcc makefile
-       makefile.darwin  =>  Darwin makefile
-       makefile.dec     =>  DEC Alpha UNIX makefile
-       makefile.freebsd =>  FreeBSD makefile
-       makefile.hpgcc   =>  HPUX makefile using gcc
-       makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
-       makefile.hp64    =>  HPUX (10.20 and 11.00) makefile, 64 bit
-       makefile.ibmc    =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
-       makefile.intel   =>  Intel C/C++ version 4.0 and later
-       libpng.icc       =>  Project file, IBM VisualAge/C++ 4.0 or later
-       makefile.netbsd  =>  NetBSD/cc makefile, PNGGCCRD, makes libpng.so.
-       makefile.ne12bsd  =>  NetBSD/cc makefile, PNGGCCRD, makes libpng12.so
-       makefile.openbsd =>  OpenBSD makefile
-       makefile.sgi     =>  Silicon Graphics IRIX (cc, creates static lib)
-       makefile.sggcc   =>  Silicon Graphics
-                            (gcc, creates libpng12.so.0.1.2.19)
-       makefile.sunos   =>  Sun makefile
-       makefile.solaris =>  Solaris 2.X makefile
-                            (gcc, creates libpng12.so.0.1.2.19)
-       makefile.so9     =>  Solaris 9 makefile
-                            (gcc, creates libpng12.so.0.1.2.19)
-       makefile.32sunu  =>  Sun Ultra 32-bit makefile
-       makefile.64sunu  =>  Sun Ultra 64-bit makefile
-       makefile.sco     =>  For SCO OSr5  ELF and Unixware 7 with Native cc
-       makefile.mips    =>  MIPS makefile
-       makefile.acorn   =>  Acorn makefile
-       makefile.amiga   =>  Amiga makefile
-       smakefile.ppc    =>  AMIGA smakefile for SAS C V6.58/7.00 PPC
-                            compiler (Requires SCOPTIONS, copied from
-                            scripts/SCOPTIONS.ppc)
-       makefile.atari   =>  Atari makefile
-       makefile.beos    =>  BEOS makefile for X86
-       makefile.bor     =>  Borland makefile (uses bcc)
-       makefile.bc32    =>  32-bit Borland C++ (all modules compiled in C mode)
-       makefile.tc3     =>  Turbo C 3.0 makefile
-       makefile.dj2     =>  DJGPP 2 makefile
-       makefile.msc     =>  Microsoft C makefile
-       makefile.vcawin32=>  makefile for Microsoft Visual C++ 5.0 and
-                            later (uses assembler code tuned for Intel MMX
-                            platform)
-       makefile.vcwin32 =>  makefile for Microsoft Visual C++ 4.0 and
-                            later (does not use assembler code)
-       makefile.os2     =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
-       pngos2.def       =>  OS/2 module definition file used by makefile.os2
-       makefile.watcom  =>  Watcom 10a+ Makefile, 32-bit flat memory model
-       makevms.com      =>  VMS build script
-       SCOPTIONS.ppc    =>  Used with smakefile.ppc
+                            (see scripts/README.txt for the list of scripts)

 Good luck, and happy coding.

-Glenn Randers-Pehrson (current maintainer)
+-Glenn Randers-Pehrson (current maintainer, since 1998)
 Internet: glennrp at users.sourceforge.net

 -Andreas Eric Dilger (former maintainer, 1996-1997)
--- a/15
+++ b/15
@@ -1,24 +1,29 @@
+/*
 TODO - list of things to do for libpng:

 Final bug fixes.
-Improve API by hiding the png_struct and png_info structs.
-Finish work on the no-floating-point version (including gamma compensation)
 Better C++ wrapper/full C++ implementation?
 Fix problem with C++ and EXTERN "C".
 cHRM transformation.
-Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+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
   (counting huffman bits/precompression?  filter inertia?  filter costs?).
 Histogram creation.
 Text conversion between different code pages (Latin-1 -> Mac and DOS).
-Should we always malloc 2^bit_depth PLTE/tRNS/hIST entries for safety?
-Build gamma tables using fixed point (and do away with floating point entirely).
+Avoid building gamma tables whenever possible.
 Use greater precision when changing to linear gamma for compositing against
  background and doing rgb-to-gray transformation.
 Investigate pre-incremented loop counters and other loop constructions.
+Add interpolated method of handling interlacing.
+Switch to the simpler zlib (zlib/libpng) license if legally possible.
+Extend pngvalid.c to validate more of the libpng transformations.
+
+*/
--- a/55
+++ b/55
@@ -1,55 +0,0 @@
-   Y2K compliance in libpng:
-   =========================
-
-      August 18, 2007
-
-      Since the PNG Development group is an ad-hoc body, we can't make
-      an official declaration.
-
-      This is your unofficial assurance that libpng from version 0.71 and
-      upward through 1.2.19 are Y2K compliant.  It is my belief that earlier
-      versions were also Y2K compliant.
-
-      Libpng only has three year fields.  One is a 2-byte unsigned integer
-      that will hold years up to 65535.  The other two hold the date in text
-      format, and will hold years up to 9999.
-
-      The integer is
-          "png_uint_16 year" in png_time_struct.
-
-      The strings are
-          "png_charp time_buffer" in png_struct and
-          "near_time_buffer", which is a local character string in png.c.
-
-      There are seven time-related functions:
-
-          png_convert_to_rfc_1123() in png.c
-            (formerly png_convert_to_rfc_1152() in error)
-          png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
-          png_convert_from_time_t() in pngwrite.c
-          png_get_tIME() in pngget.c
-          png_handle_tIME() in pngrutil.c, called in pngread.c
-          png_set_tIME() in pngset.c
-          png_write_tIME() in pngwutil.c, called in pngwrite.c
-
-      All appear to handle dates properly in a Y2K environment.  The
-      png_convert_from_time_t() function calls gmtime() to convert from system
-      clock time, which returns (year - 1900), which we properly convert to
-      the full 4-digit year.  There is a possibility that applications using
-      libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
-      function, or that they are incorrectly passing only a 2-digit year
-      instead of "year - 1900" into the png_convert_from_struct_tm() function,
-      but this is not under our control.  The libpng documentation has always
-      stated that it works with 4-digit years, and the APIs have been
-      documented as such.
-
-      The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
-      integer to hold the year, and can hold years as large as 65535.
-
-      zlib, upon which libpng depends, is also Y2K compliant.  It contains
-      no date-related code.
-
-
-         Glenn Randers-Pehrson
-         libpng maintainer
-         PNG Development Group
--- a/aclocal.m4
+++ b/aclocal.m4
--- a/arm/arm_init.c
+++ b/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 */
--- a/arm/filter_neon.S
+++ b/arm/filter_neon.S
@@ -0,0 +1,253 @@
+
+/* filter_neon.S - 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
+ */
+
+/* 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
+#   define ELF @
+#endif
+
+        .arch armv7-a
+        .fpu  neon
+
+.macro  func    name, export=0
+    .macro endfunc
+ELF     .size   \name, . - \name
+        .endfunc
+        .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
+ELF     .type   \name, STT_FUNC
+        .func   \name
+\name:
+.endm
+
+func    png_read_filter_row_sub4_neon, export=1
+        ldr             r3,  [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+1:
+        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
+        vadd.u8         d0,  d3,  d4
+        vadd.u8         d1,  d0,  d5
+        vadd.u8         d2,  d1,  d6
+        vadd.u8         d3,  d2,  d7
+        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
+        subs            r3,  r3,  #16
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_sub3_neon, export=1
+        ldr             r3,  [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+        mov             r0,  r1
+        mov             r2,  #3
+        mov             r12, #12
+        vld1.8          {q11},    [r0], r12
+1:
+        vext.8          d5,  d22, d23, #3
+        vadd.u8         d0,  d3,  d22
+        vext.8          d6,  d22, d23, #6
+        vadd.u8         d1,  d0,  d5
+        vext.8          d7,  d23, d23, #1
+        vld1.8          {q11},    [r0], r12
+        vst1.32         {d0[0]},  [r1,:32], r2
+        vadd.u8         d2,  d1,  d6
+        vst1.32         {d1[0]},  [r1], r2
+        vadd.u8         d3,  d2,  d7
+        vst1.32         {d2[0]},  [r1], r2
+        vst1.32         {d3[0]},  [r1], r2
+        subs            r3,  r3,  #12
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_up_neon, export=1
+        ldr             r3,  [r0, #4]           @ rowbytes
+1:
+        vld1.8          {q0}, [r1,:128]
+        vld1.8          {q1}, [r2,:128]!
+        vadd.u8         q0,  q0,  q1
+        vst1.8          {q0}, [r1,:128]!
+        subs            r3,  r3,  #16
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_avg4_neon, export=1
+        ldr             r12, [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+1:
+        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
+        vld4.32         {d16[],d17[],d18[],d19[]},[r2,:128]!
+        vhadd.u8        d0,  d3,  d16
+        vadd.u8         d0,  d0,  d4
+        vhadd.u8        d1,  d0,  d17
+        vadd.u8         d1,  d1,  d5
+        vhadd.u8        d2,  d1,  d18
+        vadd.u8         d2,  d2,  d6
+        vhadd.u8        d3,  d2,  d19
+        vadd.u8         d3,  d3,  d7
+        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
+        subs            r12, r12, #16
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_avg3_neon, export=1
+        push            {r4,lr}
+        ldr             r12, [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+        mov             r0,  r1
+        mov             r4,  #3
+        mov             lr,  #12
+        vld1.8          {q11},    [r0], lr
+1:
+        vld1.8          {q10},    [r2], lr
+        vext.8          d5,  d22, d23, #3
+        vhadd.u8        d0,  d3,  d20
+        vext.8          d17, d20, d21, #3
+        vadd.u8         d0,  d0,  d22
+        vext.8          d6,  d22, d23, #6
+        vhadd.u8        d1,  d0,  d17
+        vext.8          d18, d20, d21, #6
+        vadd.u8         d1,  d1,  d5
+        vext.8          d7,  d23, d23, #1
+        vld1.8          {q11},    [r0], lr
+        vst1.32         {d0[0]},  [r1,:32], r4
+        vhadd.u8        d2,  d1,  d18
+        vst1.32         {d1[0]},  [r1], r4
+        vext.8          d19, d21, d21, #1
+        vadd.u8         d2,  d2,  d6
+        vhadd.u8        d3,  d2,  d19
+        vst1.32         {d2[0]},  [r1], r4
+        vadd.u8         d3,  d3,  d7
+        vst1.32         {d3[0]},  [r1], r4
+        subs            r12, r12, #12
+        bgt             1b
+
+        pop             {r4,pc}
+endfunc
+
+.macro  paeth           rx,  ra,  rb,  rc
+        vaddl.u8        q12, \ra, \rb           @ a + b
+        vaddl.u8        q15, \rc, \rc           @ 2*c
+        vabdl.u8        q13, \rb, \rc           @ pa
+        vabdl.u8        q14, \ra, \rc           @ pb
+        vabd.u16        q15, q12, q15           @ pc
+        vcle.u16        q12, q13, q14           @ pa <= pb
+        vcle.u16        q13, q13, q15           @ pa <= pc
+        vcle.u16        q14, q14, q15           @ pb <= pc
+        vand            q12, q12, q13           @ pa <= pb && pa <= pc
+        vmovn.u16       d28, q14
+        vmovn.u16       \rx, q12
+        vbsl            d28, \rb, \rc
+        vbsl            \rx, \ra, d28
+.endm
+
+func    png_read_filter_row_paeth4_neon, export=1
+        ldr             r12, [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+        vmov.i8         d20, #0
+1:
+        vld4.32         {d4[],d5[],d6[],d7[]},    [r1,:128]
+        vld4.32         {d16[],d17[],d18[],d19[]},[r2,:128]!
+        paeth           d0,  d3,  d16, d20
+        vadd.u8         d0,  d0,  d4
+        paeth           d1,  d0,  d17, d16
+        vadd.u8         d1,  d1,  d5
+        paeth           d2,  d1,  d18, d17
+        vadd.u8         d2,  d2,  d6
+        paeth           d3,  d2,  d19, d18
+        vmov            d20, d19
+        vadd.u8         d3,  d3,  d7
+        vst4.32         {d0[0],d1[0],d2[0],d3[0]},[r1,:128]!
+        subs            r12, r12, #16
+        bgt             1b
+
+        bx              lr
+endfunc
+
+func    png_read_filter_row_paeth3_neon, export=1
+        push            {r4,lr}
+        ldr             r12, [r0, #4]           @ rowbytes
+        vmov.i8         d3,  #0
+        vmov.i8         d4,  #0
+        mov             r0,  r1
+        mov             r4,  #3
+        mov             lr,  #12
+        vld1.8          {q11},    [r0], lr
+1:
+        vld1.8          {q10},    [r2], lr
+        paeth           d0,  d3,  d20, d4
+        vext.8          d5,  d22, d23, #3
+        vadd.u8         d0,  d0,  d22
+        vext.8          d17, d20, d21, #3
+        paeth           d1,  d0,  d17, d20
+        vst1.32         {d0[0]},  [r1,:32], r4
+        vext.8          d6,  d22, d23, #6
+        vadd.u8         d1,  d1,  d5
+        vext.8          d18, d20, d21, #6
+        paeth           d2,  d1,  d18, d17
+        vext.8          d7,  d23, d23, #1
+        vld1.8          {q11},    [r0], lr
+        vst1.32         {d1[0]},  [r1], r4
+        vadd.u8         d2,  d2,  d6
+        vext.8          d19, d21, d21, #1
+        paeth           d3,  d2,  d19, d18
+        vst1.32         {d2[0]},  [r1], r4
+        vmov            d4,  d19
+        vadd.u8         d3,  d3,  d7
+        vst1.32         {d3[0]},  [r1], r4
+        subs            r12, r12, #12
+        bgt             1b
+
+        pop             {r4,pc}
+endfunc
+#endif /* PNG_ARM_NEON_OPT > 0 */
+#endif /* PNG_ARM_NEON_IMPLEMENTATION == 2 (assembler) */
+#endif /* READ */
--- a/arm/filter_neon_intrinsics.c
+++ b/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 */
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,25 +1,224 @@
 #! /bin/sh
-# a quick hack script to generate necessary files from 
-# auto* tools.
 #
-# WARNING: if you run this you will change the versions
-# of the tools which are used and, maybe, required!
-        touch Makefile.am configure.ac
-{
-	echo "running libtoolize" >&2
-	libtoolize --copy --automake
-} && {
-	echo "running aclocal" >&2
-	aclocal
-} && {
-	echo "running autoheader [ignore the warnings]" >&2
-	autoheader
-} && {
-	echo "running automake" >&2
-	automake --foreign -a -c
-} && {
-	echo "running autoconf" >&2
-	autoconf
-} &&
-	echo "autogen complete" >&2 ||
-	echo "ERROR: autogen.sh failed, autogen is incomplete" >&2
+# 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;;
+
+      --clean)
+         clean=1;;
+
+      *)
+         exec >&2
+         echo "$0: usage: ./autogen.sh"
+         if test -d .git
+         then
+            echo "  ./autogen.sh generates the configure script and"
+            echo "  Makefile.in, or refreshes them after changes to Makefile.am"
+            echo "  or configure.ac.  You may prefer to just run autoreconf."
+         elif test -z "$maintainer"
+         then
+            echo "  DO NOT RUN THIS SCRIPT."
+            echo "  If you need to change Makefile.am or configure.ac then you"
+            echo "  also need to run ./configure --enable-maintainer-mode and"
+            echo "  use the appropriate autotools, *NOT* this script, to update"
+            echo "  everything, please check the documentation of autoreconf."
+            echo "  WARNING: libpng is intentionally generated with a known,"
+            echo "  fixed, set of autotools.  It is known *NOT* to work with"
+            echo "  the collection of autotools distributed on highly reputable"
+            echo "  operating systems."
+            echo "  Remember: autotools is GNU software, you are expected to"
+            echo "  pay for support."
+         else
+            echo "  You have run autogen.sh with --maintainer enabled and you"
+            echo "  are not using a GIT distribution, then you have given an"
+            echo "  unrecognized argument.  This is not good. --maintainer"
+            echo "  switches off any assumptions that you might not know what"
+            echo "  you are doing."
+         fi
+         exit 1;;
+   esac
+
+   shift
+done
+#
+# First check for a set of the autotools files; if absent then this is assumed
+# to be a GIT version and the local autotools must be used.  If present this
+# is a tarball distribution and the script should not be used.  If partially
+# present bad things are happening.
+#
+# The autotools generated files:
+libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in\
+   config.sub configure depcomp install-sh ltmain.sh missing test-driver"
+#
+# Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
+# versions than those required by configure.ac):
+libpng_autotools_extra="compile"
+#
+# These are separate because 'maintainer-clean' does not remove them.
+libpng_libtool_files="scripts/libtool.m4 scripts/ltoptions.m4\
+   scripts/ltsugar.m4 scripts/ltversion.m4 scripts/lt~obsolete.m4"
+
+libpng_autotools_dirs="autom4te.cache" # not required
+#
+# The configure generated files:
+libpng_configure_files="Makefile config.h config.log config.status\
+   libpng-config libpng.pc libtool stamp-h1"
+
+libpng_configure_dirs=".deps"
+#
+# We must remove the configure generated files as well as the autotools
+# generated files if autotools are regenerated because otherwise if configure
+# has been run without "--enable-maintainer-mode" make can do a partial update
+# of Makefile.  These functions do the two bits of cleaning.
+clean_autotools(){
+   rm -rf $libpng_autotools_files $libpng_libtool_files $libpng_autotools_dirs
+   rm -rf $libpng_autotools_extra
+}
+
+clean_configure(){
+   rm -rf $libpng_configure_files $libpng_configure_dirs
+}
+#
+# Clean: remove everything (this is to help with testing)
+if test -n "$clean"
+then
+   clean_configure
+   if test -n "$maintainer"
+   then
+      clean_autotools
+   fi
+
+   exit 0
+fi
+#
+# Validate the distribution.
+libpng_autotools_file_found=
+libpng_autotools_file_missing=
+for file in $libpng_autotools_files
+do
+   if test -f  "$file"
+   then
+      libpng_autotools_file_found=1
+   else
+      libpng_autotools_file_missing=1
+   fi
+done
+#
+# Presence of one of these does not *invalidate* missing, but absence
+# invalidates found.
+for file in $libpng_libtool_files
+do
+   if test ! -f "$file"
+   then
+      libpng_autotools_file_missing=1
+   fi
+done
+#
+# The cache directory doesn't matter - it will be regenerated and does not exist
+# anyway in a tarball.
+#
+# Either everything is missing or everything is there, the --maintainer option
+# just changes this so that the mode is set to generate all the files.
+mode=
+if test -z "$libpng_autotools_file_found" -o -n "$maintainer"
+then
+   mode="autoreconf"
+else
+   if test -n "$libpng_autotools_file_missing"
+   then
+      mode="broken"
+   else
+      mode="configure"
+   fi
+fi
+#
+# So:
+case "$mode" in
+   autoreconf)
+      # Clean in case configure files exist
+      clean_configure
+      clean_autotools
+      # Everything must be initialized, so use --force
+      if autoreconf --warnings=all --force --install
+      then
+         missing=
+         for file in $libpng_autotools_files
+         do
+            test -f "$file" || missing=1
+         done
+         # ignore the cache directory
+         test -z "$missing" || {
+            exec >&2
+            echo "autoreconf was run, but did not produce all the expected"
+            echo "files.  It is likely that your autotools installation is"
+            echo "not compatible with that expected by libpng."
+            exit 1
+         }
+      else
+         exec >&2
+         echo "autoreconf failed: your version of autotools is incompatible"
+         echo "with this libpng version.  Please use a distributed archive"
+         echo "(which includes the autotools generated files) and run configure"
+         echo "instead."
+         exit 1
+      fi;;
+
+   configure)
+      if test -d .git
+      then
+         exec >&2
+         echo "ERROR: running autoreconf on an initialized sytem"
+         echo "  This is not necessary; it is only necessary to remake the"
+         echo "  autotools generated files if Makefile.am or configure.ac"
+         echo "  change and make does the right thing with:"
+         echo
+         echo "     ./configure --enable-maintainer-mode."
+         echo
+         echo "  You can run autoreconf yourself if you don't like maintainer"
+         echo "  mode and you can also just run autoreconf -f -i to initialize"
+         echo "  everything in the first place; this script is only for"
+         echo "  compatibility with prior releases."
+         exit 1
+      else
+         exec >&2
+         echo "autogen.sh is intended only to generate 'configure' on systems"
+         echo "that do not have it.  You have a complete 'configure', if you"
+         echo "need to change Makefile.am or configure.ac you also need to"
+         echo "run configure with the --enable-maintainer-mode option."
+         exit 1
+      fi;;
+
+   broken)
+      exec >&2
+      echo "Your system has a partial set of autotools generated files."
+      echo "autogen.sh is unable to proceed.  The full set of files is"
+      echo "contained in the libpng 'tar' distribution archive and you do"
+      echo "not need to run autogen.sh if you use it."
+      exit 1;;
+esac
--- a/config.guess
+++ b/config.guess
--- a/config.h.in
+++ b/config.h.in
@@ -1,79 +0,0 @@
-/* config.h.in.  Generated from configure.ac by autoheader.  */
-
-/* Define to 1 if you have the <dlfcn.h> header file. */
-#undef HAVE_DLFCN_H
-
-/* Define to 1 if you have the <inttypes.h> header file. */
-#undef HAVE_INTTYPES_H
-
-/* Define to 1 if you have the `m' library (-lm). */
-#undef HAVE_LIBM
-
-/* Define to 1 if you have the `z' library (-lz). */
-#undef HAVE_LIBZ
-
-/* Define to 1 if you have the <malloc.h> header file. */
-#undef HAVE_MALLOC_H
-
-/* Define to 1 if you have the <memory.h> header file. */
-#undef HAVE_MEMORY_H
-
-/* Define to 1 if you have the `memset' function. */
-#undef HAVE_MEMSET
-
-/* Define to 1 if you have the `pow' function. */
-#undef HAVE_POW
-
-/* Define to 1 if you have the <stdint.h> header file. */
-#undef HAVE_STDINT_H
-
-/* Define to 1 if you have the <stdlib.h> header file. */
-#undef HAVE_STDLIB_H
-
-/* Define to 1 if you have the <strings.h> header file. */
-#undef HAVE_STRINGS_H
-
-/* Define to 1 if you have the <string.h> header file. */
-#undef HAVE_STRING_H
-
-/* Define to 1 if you have the <sys/stat.h> header file. */
-#undef HAVE_SYS_STAT_H
-
-/* Define to 1 if you have the <sys/types.h> header file. */
-#undef HAVE_SYS_TYPES_H
-
-/* Define to 1 if you have the <unistd.h> header file. */
-#undef HAVE_UNISTD_H
-
-/* Name of package */
-#undef PACKAGE
-
-/* Define to the address where bug reports for this package should be sent. */
-#undef PACKAGE_BUGREPORT
-
-/* Define to the full name of this package. */
-#undef PACKAGE_NAME
-
-/* Define to the full name and version of this package. */
-#undef PACKAGE_STRING
-
-/* Define to the one symbol short name of this package. */
-#undef PACKAGE_TARNAME
-
-/* Define to the version of this package. */
-#undef PACKAGE_VERSION
-
-/* Define to 1 if you have the ANSI C header files. */
-#undef STDC_HEADERS
-
-/* Define to 1 if your <sys/time.h> declares `struct tm'. */
-#undef TM_IN_SYS_TIME
-
-/* Version number of package */
-#undef VERSION
-
-/* Define to empty if `const' does not conform to ANSI C. */
-#undef const
-
-/* Define to `unsigned int' if <sys/types.h> does not define. */
-#undef size_t
--- a/config.sub
+++ b/config.sub
--- a/22270
+++ b/22270
--- a/configure.ac
+++ b/configure.ac
@@ -14,66 +14,154 @@ 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], [1.2.19], [png-mng-implement@lists.sourceforge.net])
-AM_INIT_AUTOMAKE
-dnl stop configure from automagically running automake
+AC_INIT([libpng],[1.6.17],[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=1.2.19
+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=1.6.17
 PNGLIB_MAJOR=1
-PNGLIB_MINOR=2
-PNGLIB_RELEASE=19
+PNGLIB_MINOR=6
+PNGLIB_RELEASE=17

 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
-AC_PROG_LD
+AM_PROG_AS
+LT_PATH_LD
 AC_PROG_CPP
-AC_CHECK_TOOL(SED, sed, :)
+AC_PROG_AWK
 AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
-AC_PROG_LIBTOOL
+
+dnl libtool/libtoolize; version 2.4.2 is the tested version, this or any
+dnl compatible later version may be used
+LT_INIT([win32-dll])
+LT_PREREQ([2.4.2])
+
+# Some awks crash when confronted with pnglibconf.dfa, do a test run now
+# to make sure this doesn't happen
+AC_MSG_CHECKING([that AWK works])
+if ${AWK} -f ${srcdir}/scripts/options.awk out="/dev/null" version=search\
+   ${srcdir}/pngconf.h ${srcdir}/scripts/pnglibconf.dfa\
+   ${srcdir}/pngusr.dfa 1>&2
+then
+   AC_MSG_RESULT([ok])
+else
+   AC_MSG_FAILURE([failed], 1)
+fi
+
+# This is a remnant of the old cc -E validation, where it may have been
+# necessary to use a different preprocessor for .dfn files
+DFNCPP="$CPP"
+AC_SUBST(DFNCPP)
+
+# -Werror cannot be passed to GCC in CFLAGS because configure will fail (it
+# checks the compiler with a program that generates a warning), add the
+# following option to deal with this
+AC_ARG_VAR(PNG_COPTS,
+   [additional flags for the C compiler, use this for options that would]
+   [cause configure itself to fail])
+AC_ARG_ENABLE(werror,
+   AS_HELP_STRING([[[--enable-werror[=OPT]]]],
+      [Pass -Werror or the given argument to the compiler if it is supported]),
+   [test "$enable_werror" = "yes" && enable_werror="-Werror"
+    if test "$enable_werror" != "no"; then
+      sav_CFLAGS="$CFLAGS"
+      CFLAGS="$enable_werror $CFLAGS"
+      AC_MSG_CHECKING([if the compiler allows $enable_werror])
+      AC_COMPILE_IFELSE(
+         [AC_LANG_SOURCE([
+            [int main(int argc, char **argv){]
+            [return argv[argc-1][0];]
+            [}]])],
+         AC_MSG_RESULT(yes)
+         PNG_COPTS="$PNG_COPTS $enable_werror",
+         AC_MSG_RESULT(no))
+      CFLAGS="$sav_CFLAGS"
+    fi],)

 # Checks for header files.
 AC_HEADER_STDC
-AC_CHECK_HEADERS([malloc.h stdlib.h string.h strings.h])

 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
 AC_TYPE_SIZE_T
 AC_STRUCT_TM
+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_LIB(z, zlibVersion, , AC_ERROR([zlib not installed]))
+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,
+   AS_HELP_STRING([[[--with-zlib-prefix]]],
+      [prefix that may have been used in installed zlib]),
+      [ZPREFIX=${withval}],
+      [ZPREFIX='z_'])
+AC_CHECK_LIB(z, zlibVersion, ,
+    AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, , AC_MSG_ERROR(zlib not installed)))

-LIBPNG_DEFINES=-DPNG_CONFIGURE_LIBPNG
-AC_MSG_CHECKING(
-  [if assembler code in pnggccrd.c can be compiled without PNG_NO_MMX_CODE])
-AC_TRY_COMPILE(
-  [#include "$srcdir/pnggccrd.c"],
-  [return 0;],
-  AC_MSG_RESULT(yes)
-  LIBPNG_NO_MMX="",
-  AC_MSG_RESULT(no)
-  LIBPNG_NO_MMX=-DPNG_NO_MMX_CODE)
-LIBPNG_DEFINES=$LIBPNG_DEFINES\ $LIBPNG_NO_MMX
-AC_SUBST(LIBPNG_DEFINES)
-AC_SUBST(LIBPNG_NO_MMX)
+# The following is for pngvalid, to ensure it catches FP errors even on
+# platforms that don't enable FP exceptions, the function appears in the math
+# library (typically), it's not an error if it is not found.
+AC_CHECK_LIB([m], [feenableexcept])
+AC_CHECK_FUNCS([feenableexcept])
+
+AC_MSG_CHECKING([if using Solaris linker])
+SLD=`$LD --version 2>&1 | grep Solaris`
+if test "$SLD"; then
+    have_solaris_ld=yes
+    AC_MSG_RESULT(yes)
+else
+    have_solaris_ld=no
+    AC_MSG_RESULT(no)
+fi
+AM_CONDITIONAL(HAVE_SOLARIS_LD, test "$have_solaris_ld" = "yes")

 AC_MSG_CHECKING([if libraries can be versioned])
-GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
+# Special case for PE/COFF platforms: ld reports
+# support for version-script, but doesn't actually
+# DO anything with it.
+case $host in
+*cygwin* | *mingw32* | *interix* )
+    have_ld_version_script=no
+    AC_MSG_RESULT(no)
+;;
+* )
+
+if test "$have_solaris_ld" = "yes"; then
+    GLD=`$LD --help < /dev/null 2>&1 | grep 'M mapfile'`
+else
+    GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
+fi
+
 if test "$GLD"; then
    have_ld_version_script=yes
    AC_MSG_RESULT(yes)
@@ -82,8 +170,21 @@ else
    AC_MSG_RESULT(no)
    AC_MSG_WARN(*** You have not enabled versioned symbols.)
 fi
+;;
+esac
+
 AM_CONDITIONAL(HAVE_LD_VERSION_SCRIPT, test "$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=" \
+                  | ${SED-sed} -e "s:^PREFIX=::" -e "s:__USER_LABEL_PREFIX__::"`
+    AC_SUBST(SYMBOL_PREFIX)
+    AC_MSG_RESULT($SYMBOL_PREFIX)
+fi
+
 # Substitutions for .in files
 AC_SUBST(PNGLIB_VERSION)
 AC_SUBST(PNGLIB_MAJOR)
@@ -93,45 +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])

-# Allow the old version number library, libpng.so, to be removed from
-# the build
-AC_ARG_WITH(libpng-compat,
-	AC_HELP_STRING([--with-libpng-compat],
-		[Generate the obsolete libpng.so library @<:@default=yes@:>@]),
-	[if test "${withval}" = no; then
-		compatlib=
-		AC_MSG_NOTICE([libpng.so will not be built])
-	else
-		compatlib=libpng.la
-	fi],
-	[compatlib=libpng.la])
-AC_SUBST([compatlib])
+# Support for prefixes to the API function names; this will generate defines
+# at the start of the build to rename exported library functions
+AC_ARG_WITH(libpng-prefix,
+   AS_HELP_STRING([[[--with-libpng-prefix]]],
+      [prefix libpng exported function (API) names with the given value]),
+   [if test "${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 "$enable_unversioned_libpng_config" != "no"])
+
+# HOST SPECIFIC OPTIONS
+# =====================
+#
+# ARM
+# ===
+#
+# ARM NEON (SIMD) support.
+
+AC_ARG_ENABLE([arm-neon],
+   AS_HELP_STRING([[[--enable-arm-neon]]],
+      [Enable ARM NEON optimizations: =no/off, check, api, yes/on:]
+      [no/off: disable the optimizations; check: use internal checking code]
+      [(deprecated and poorly supported); api: disable by default, enable by]
+      [a call to png_set_option; yes/on: turn on unconditionally.]
+      [If not specified: determined by the compiler.]),
+   [case "$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:scripts/libpng.pc-configure.in])
-AC_CONFIG_FILES([libpng-config:scripts/libpng-config.in],
-		[chmod +x libpng-config])
+AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in])
+AC_CONFIG_FILES([libpng-config:libpng-config.in],
+   [chmod +x libpng-config])

 AC_OUTPUT
--- a/contrib/README.txt
+++ b/contrib/README.txt
@@ -0,0 +1,4 @@
+
+This "contrib" directory contains contributions which are not necessarily under
+the libpng license, although all are open source.  They are not part of
+libpng proper and are not used for building the library.
--- a/contrib/arm-neon/README
+++ b/contrib/arm-neon/README
@@ -0,0 +1,83 @@
+OPERATING SYSTEM SPECIFIC ARM NEON DETECTION
+--------------------------------------------
+
+Detection of the ability to exexcute 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.
--- a/contrib/arm-neon/android-ndk.c
+++ b/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;
+}
--- a/contrib/arm-neon/linux-auxv.c
+++ b/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;
+}
--- a/contrib/arm-neon/linux.c
+++ b/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;
+}
--- a/contrib/conftest/README
+++ b/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.
--- a/contrib/conftest/read.dfa
+++ b/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
--- a/contrib/conftest/s_read.dfa
+++ b/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
--- a/contrib/conftest/s_write.dfa
+++ b/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
--- a/contrib/conftest/simple.dfa
+++ b/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
--- a/contrib/conftest/write.dfa
+++ b/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')
--- a/contrib/examples/README.txt
+++ b/contrib/examples/README.txt
@@ -0,0 +1,24 @@
+
+This directory (contrib/examples) contains examples of libpng usage.
+
+NO COPYRIGHT RIGHTS ARE CLAIMED TO ANY OF THE FILES IN THIS DIRECTORY.
+
+To the extent possible under law, the authors have waived all copyright and
+related or neighboring rights to this work.  This work is published from:
+United States.
+
+The files may be used freely in any way.  The intention is that appropriate
+parts of the files be used in other libpng-using programs without any need for
+the authors of the using code to seek copyright or license from the original
+authors.
+
+The source code and comments in this directory are the original work of the
+people named below.  No other person or organization has made contributions to
+the work in this directory.
+
+ORIGINAL AUTHORS
+    The following people have contributed to the code in this directory.  None
+    of the people below claim any rights with regard to the contents of this
+    directory.
+
+    John Bowler <jbowler@acm.org>
--- a/contrib/examples/iccfrompng.c
+++ b/contrib/examples/iccfrompng.c
@@ -0,0 +1,180 @@
+/*- iccfrompng
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Extract any icc profiles found in the given PNG files.  This is a simple
+ * example of a program 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
+ * in this file won't work reliably for such data because it only looks for the
+ * information in the section of the file that preceeds the image data.
+ *
+ * Compile and link against libpng and zlib, plus anything else required on the
+ * system you use.
+ *
+ * To use supply a list of PNG files containing iCCP chunks, the chunks will be
+ * extracted to a similarly named file with the extension replaced by 'icc',
+ * which will be overwritten without warning.
+ */
+#include <stdlib.h>
+#include <setjmp.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <png.h>
+
+static int verbose = 1;
+static png_byte no_profile[] = "no profile";
+
+static png_bytep
+extract(FILE *fp, png_uint_32 *proflen)
+{
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+   png_infop info_ptr = NULL;
+   png_bytep result = NULL;
+
+   /* Initialize for error or no profile: */
+   *proflen = 0;
+
+   if (png_ptr == NULL)
+   {
+      fprintf(stderr, "iccfrompng: version library mismatch?\n");
+      return 0;
+   }
+
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+      return 0;
+   }
+
+   png_init_io(png_ptr, fp);
+
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
+      png_error(png_ptr, "OOM allocating info structure");
+
+   png_read_info(png_ptr, info_ptr);
+
+   {
+      png_charp name;
+      int compression_type;
+      png_bytep profile;
+
+      if (png_get_iCCP(png_ptr, info_ptr, &name, &compression_type, &profile,
+         proflen) & PNG_INFO_iCCP)
+      {
+         result = malloc(*proflen);
+         if (result != NULL)
+            memcpy(result, profile, *proflen);
+
+         else
+            png_error(png_ptr, "OOM allocating profile buffer");
+      }
+
+      else
+	result = no_profile;
+   }
+
+   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+   return result;
+}
+
+static int
+extract_one_file(const char *filename)
+{
+   int result = 0;
+   FILE *fp = fopen(filename, "rb");
+
+   if (fp != NULL)
+   {
+      png_uint_32 proflen = 0;
+      png_bytep profile = extract(fp, &proflen);
+
+      if (profile != NULL && profile != no_profile)
+      {
+         size_t len;
+         char *output;
+
+         {
+            const char *ep = strrchr(filename, '.');
+
+            if (ep != NULL)
+               len = ep-filename;
+
+            else
+               len = strlen(filename);
+         }
+
+         output = malloc(len + 5);
+         if (output != NULL)
+         {
+            FILE *of;
+
+            memcpy(output, filename, len);
+            strcpy(output+len, ".icc");
+
+            of = fopen(output, "wb");
+            if (of != NULL)
+            {
+               if (fwrite(profile, proflen, 1, of) == 1 &&
+                  fflush(of) == 0 &&
+                  fclose(of) == 0)
+               {
+                  if (verbose)
+                     printf("%s -> %s\n", filename, output);
+                  /* Success return */
+                  result = 1;
+               }
+
+               else
+               {
+                  fprintf(stderr, "%s: error writing profile\n", output);
+                  if (remove(output))
+                     fprintf(stderr, "%s: could not remove file\n", output);
+               }
+            }
+
+            else
+               fprintf(stderr, "%s: failed to open output file\n", output);
+
+            free(output);
+         }
+
+         else
+            fprintf(stderr, "%s: OOM allocating string!\n", filename);
+
+         free(profile);
+      }
+
+      else if (verbose && profile == no_profile)
+	printf("%s has no profile\n", filename);
+   }
+
+   else
+      fprintf(stderr, "%s: could not open file\n", filename);
+
+   return result;
+}
+
+int
+main(int argc, char **argv)
+{
+   int i;
+   int extracted = 0;
+
+   for (i=1; i<argc; ++i)
+   {
+      if (strcmp(argv[i], "-q") == 0)
+         verbose = 0;
+
+      else if (extract_one_file(argv[i]))
+         extracted = 1;
+   }
+
+   /* Exit code is true if any extract succeeds */
+   return extracted == 0;
+}
--- a/contrib/examples/pngpixel.c
+++ b/contrib/examples/pngpixel.c
@@ -0,0 +1,368 @@
+/*- pngpixel
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Read a single pixel value from a PNG file.
+ *
+ * This code illustrates basic 'by-row' reading of a PNG file using libpng.
+ * Rows are read until a particular pixel is found; the value of this pixel is
+ * then printed on stdout.
+ *
+ * The code illustrates how to do this on interlaced as well as non-interlaced
+ * images.  Normally you would call png_set_interlace_handling() to have libpng
+ * deal with the interlace for you, but that obliges you to buffer half of the
+ * image to assemble the interlaced rows.  In this code
+ * png_set_interlace_handling() is not called and, instead, the code handles the
+ * interlace passes directly looking for the required pixel.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <setjmp.h> /* required for error handling */
+
+/* Normally use <png.h> here to get the installed libpng, but this is done to
+ * ensure the code picks up the local libpng implementation:
+ */
+#include "../../png.h"
+
+/* Return component 'c' of pixel 'x' from the given row. */
+static unsigned int
+component(png_const_bytep row, png_uint_32 x, unsigned int c,
+   unsigned int bit_depth, unsigned int channels)
+{
+   /* PNG images can be up to 2^31 pixels wide, but this means they can be up to
+    * 2^37 bits wide (for a 64-bit pixel - the largest possible) and hence 2^34
+    * bytes wide.  Since the row fitted into memory, however, the following must
+    * work:
+    */
+   png_uint_32 bit_offset_hi = bit_depth * ((x >> 6) * channels);
+   png_uint_32 bit_offset_lo = bit_depth * ((x & 0x3f) * channels + c);
+
+   row = (png_const_bytep)(((PNG_CONST png_byte (*)[8])row) + bit_offset_hi);
+   row += bit_offset_lo >> 3;
+   bit_offset_lo &= 0x07;
+
+   /* PNG pixels are packed into bytes to put the first pixel in the highest
+    * bits of the byte and into two bytes for 16-bit values with the high 8 bits
+    * first, so:
+    */
+   switch (bit_depth)
+   {
+      case 1: return (row[0] >> (7-bit_offset_lo)) & 0x01;
+      case 2: return (row[0] >> (6-bit_offset_lo)) & 0x03;
+      case 4: return (row[0] >> (4-bit_offset_lo)) & 0x0f;
+      case 8: return row[0];
+      case 16: return (row[0] << 8) + row[1];
+      default:
+         /* This should never happen; it indicates a bug in this program or in
+          * libpng itself:
+          */
+         fprintf(stderr, "pngpixel: invalid bit depth %u\n", bit_depth);
+         exit(1);
+   }
+}
+
+/* Print a pixel from a row returned by libpng; determine the row format, find
+ * the pixel, and print the relevant information to stdout.
+ */
+static void
+print_pixel(png_structp png_ptr, png_infop info_ptr, png_const_bytep row,
+   png_uint_32 x)
+{
+   PNG_CONST unsigned int bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+
+   switch (png_get_color_type(png_ptr, info_ptr))
+   {
+      case PNG_COLOR_TYPE_GRAY:
+         printf("GRAY %u\n", component(row, x, 0, bit_depth, 1));
+         return;
+
+      /* The palette case is slightly more difficult - the palette and, if
+       * present, the tRNS ('transparency', though the values are really
+       * opacity) data must be read to give the full picture:
+       */
+      case PNG_COLOR_TYPE_PALETTE:
+         {
+            PNG_CONST unsigned int index = component(row, x, 0, bit_depth, 1);
+            png_colorp palette = NULL;
+            int num_palette = 0;
+
+            if ((png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) &
+               PNG_INFO_PLTE) && num_palette > 0 && palette != NULL)
+            {
+               png_bytep trans_alpha = NULL;
+               int num_trans = 0;
+               if ((png_get_tRNS(png_ptr, info_ptr, &trans_alpha, &num_trans,
+                  NULL) & PNG_INFO_tRNS) && num_trans > 0 &&
+                  trans_alpha != NULL)
+                  printf("INDEXED %u = %d %d %d %d\n", index,
+                     palette[index].red, palette[index].green,
+                     palette[index].blue,
+                     index < num_trans ? trans_alpha[index] : 255);
+
+               else /* no transparency */
+                  printf("INDEXED %u = %d %d %d\n", index,
+                     palette[index].red, palette[index].green,
+                     palette[index].blue);
+            }
+
+            else
+               printf("INDEXED %u = invalid index\n", index);
+         }
+         return;
+
+      case PNG_COLOR_TYPE_RGB:
+         printf("RGB %u %u %u\n", component(row, x, 0, bit_depth, 3),
+            component(row, x, 1, bit_depth, 3),
+            component(row, x, 2, bit_depth, 3));
+         return;
+
+      case PNG_COLOR_TYPE_GRAY_ALPHA:
+         printf("GRAY+ALPHA %u %u\n", component(row, x, 0, bit_depth, 2),
+            component(row, x, 1, bit_depth, 2));
+         return;
+
+      case PNG_COLOR_TYPE_RGB_ALPHA:
+         printf("RGBA %u %u %u %u\n", component(row, x, 0, bit_depth, 4),
+            component(row, x, 1, bit_depth, 4),
+            component(row, x, 2, bit_depth, 4),
+            component(row, x, 3, bit_depth, 4));
+         return;
+
+      default:
+         png_error(png_ptr, "pngpixel: invalid color type");
+   }
+}
+
+int main(int argc, const char **argv)
+{
+   /* This program uses the default, <setjmp.h> based, libpng error handling
+    * mechanism, therefore any local variable that exists before the call to
+    * setjmp and is changed after the call to setjmp returns successfully must
+    * be declared with 'volatile' to ensure that their values don't get
+    * destroyed by longjmp:
+    */
+   volatile int result = 1/*fail*/;
+
+   if (argc == 4)
+   {
+      long x = atol(argv[1]);
+      long y = atol(argv[2]);
+      FILE *f = fopen(argv[3], "rb");
+      volatile png_bytep row = NULL;
+
+      if (f != NULL)
+      {
+         /* libpng requires a callback function for handling errors; this
+          * callback must not return.  The default callback function uses a
+          * stored <setjmp.h> style jmp_buf which is held in a png_struct and
+          * writes error messages to stderr.  Creating the png_struct is a
+          * little tricky; just copy the following code.
+          */
+         png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
+            NULL, NULL, NULL);
+
+         if (png_ptr != NULL)
+         {
+            png_infop info_ptr = png_create_info_struct(png_ptr);
+
+            if (info_ptr != NULL)
+            {
+               /* Declare stack variables to hold pointers to locally allocated
+                * data.
+                */
+
+               /* Initialize the error control buffer: */
+               if (setjmp(png_jmpbuf(png_ptr)) == 0)
+               {
+                  png_uint_32 width, height;
+                  int bit_depth, color_type, interlace_method,
+                     compression_method, filter_method;
+                  png_bytep row_tmp;
+
+                  /* Now associate the recently opened (FILE*) with the default
+                   * libpng initialization functions.  Sometimes libpng is
+                   * compiled without stdio support (it can be difficult to do
+                   * in some environments); in that case you will have to write
+                   * your own read callback to read data from the (FILE*).
+                   */
+                  png_init_io(png_ptr, f);
+
+                  /* And read the first part of the PNG file - the header and
+                   * all the information up to the first pixel.
+                   */
+                  png_read_info(png_ptr, info_ptr);
+
+                  /* This fills in enough information to tell us the width of
+                   * each row in bytes, allocate the appropriate amount of
+                   * space.  In this case png_malloc is used - it will not
+                   * return if memory isn't available.
+                   */
+                  row = png_malloc(png_ptr, png_get_rowbytes(png_ptr,
+                     info_ptr));
+
+                  /* To avoid the overhead of using a volatile auto copy row_tmp
+                   * to a local here - just use row for the png_free below.
+                   */
+                  row_tmp = row;
+
+                  /* All the information we need is in the header is returned by
+                   * png_get_IHDR, if this fails we can now use 'png_error' to
+                   * signal the error and return control to the setjmp above.
+                   */
+                  if (png_get_IHDR(png_ptr, info_ptr, &width, &height,
+                     &bit_depth, &color_type, &interlace_method,
+                     &compression_method, &filter_method))
+                  {
+                     int passes, pass;
+
+                     /* png_set_interlace_handling returns the number of
+                      * passes required as well as turning on libpng's
+                      * handling, but since we do it ourselves this is
+                      * necessary:
+                      */
+                     switch (interlace_method)
+                     {
+                        case PNG_INTERLACE_NONE:
+                           passes = 1;
+                           break;
+
+                        case PNG_INTERLACE_ADAM7:
+                           passes = PNG_INTERLACE_ADAM7_PASSES;
+                           break;
+
+                        default:
+                           png_error(png_ptr, "pngpixel: unknown interlace");
+                     }
+
+                     /* Now read the pixels, pass-by-pass, row-by-row: */
+                     png_start_read_image(png_ptr);
+
+                     for (pass=0; pass<passes; ++pass)
+                     {
+                        png_uint_32 ystart, xstart, ystep, xstep;
+                        png_uint_32 py;
+
+                        if (interlace_method == PNG_INTERLACE_ADAM7)
+                        {
+                           /* Sometimes the whole pass is empty because the
+                            * image is too narrow or too short.  libpng
+                            * expects to be called for each row that is
+                            * present in the pass, so it may be necessary to
+                            * skip the loop below (over py) if the image is
+                            * too narrow.
+                            */
+                           if (PNG_PASS_COLS(width, pass) == 0)
+                              continue;
+
+                           /* We need the starting pixel and the offset
+                            * between each pixel in this pass; use the macros
+                            * in png.h:
+                            */
+                           xstart = PNG_PASS_START_COL(pass);
+                           ystart = PNG_PASS_START_ROW(pass);
+                           xstep = PNG_PASS_COL_OFFSET(pass);
+                           ystep = PNG_PASS_ROW_OFFSET(pass);
+                        }
+
+                        else
+                        {
+                           ystart = xstart = 0;
+                           ystep = xstep = 1;
+                        }
+
+                        /* To find the pixel, loop over 'py' for each pass
+                         * reading a row and then checking to see if it
+                         * contains the pixel.
+                         */
+                        for (py = ystart; py < height; py += ystep)
+                        {
+                           png_uint_32 px, ppx;
+
+                           /* png_read_row takes two pointers.  When libpng
+                            * handles the interlace the first is filled in
+                            * pixel-by-pixel, and the second receives the same
+                            * pixels but they are replicated across the
+                            * unwritten pixels so far for each pass.  When we
+                            * do the interlace, however, they just contain
+                            * the pixels from the interlace pass - giving
+                            * both is wasteful and pointless, so we pass a
+                            * NULL pointer.
+                            */
+                           png_read_row(png_ptr, row_tmp, NULL);
+
+                           /* Now find the pixel if it is in this row; there
+                            * are, of course, much better ways of doing this
+                            * than using a for loop:
+                            */
+                           if (y == py) for (px = xstart, ppx = 0;
+                              px < width; px += xstep, ++ppx) if (x == px)
+                           {
+                              /* 'ppx' is the index of the pixel in the row
+                               * buffer.
+                               */
+                              print_pixel(png_ptr, info_ptr, row_tmp, ppx);
+
+                              /* Now terminate the loops early - we have
+                               * found and handled the required data.
+                               */
+                              goto pass_loop_end;
+                           } /* x loop */
+                        } /* y loop */
+                     } /* pass loop */
+
+                     /* Finally free the temporary buffer: */
+                  pass_loop_end:
+                     row = NULL;
+                     png_free(png_ptr, row_tmp);
+                  }
+
+                  else
+                     png_error(png_ptr, "pngpixel: png_get_IHDR failed");
+
+               }
+
+               else
+               {
+                  /* Else libpng has raised an error.  An error message has
+                   * already been output, so it is only necessary to clean up
+                   * locally allocated data:
+                   */
+                  if (row != NULL)
+                  {
+                     /* The default implementation of png_free never errors out
+                      * (it just crashes if something goes wrong), but the safe
+                      * way of using it is still to clear 'row' before calling
+                      * png_free:
+                      */
+                     png_bytep row_tmp = row;
+                     row = NULL;
+                     png_free(png_ptr, row_tmp);
+                  }
+               }
+
+               png_destroy_info_struct(png_ptr, &info_ptr);
+            }
+
+            else
+               fprintf(stderr, "pngpixel: out of memory allocating png_info\n");
+
+            png_destroy_read_struct(&png_ptr, NULL, NULL);
+         }
+
+         else
+            fprintf(stderr, "pngpixel: out of memory allocating png_struct\n");
+      }
+
+      else
+         fprintf(stderr, "pngpixel: %s: could not open file\n", argv[3]);
+   }
+
+   else
+      /* Wrong number of arguments */
+      fprintf(stderr, "pngpixel: usage: pngpixel x y png-file\n");
+
+   return result;
+}
--- a/contrib/examples/pngtopng.c
+++ b/contrib/examples/pngtopng.c
@@ -0,0 +1,92 @@
+/*- pngtopng
+ *
+ * COPYRIGHT: Written by John Cunningham Bowler, 2011.
+ * To the extent possible under law, the author has waived all copyright and
+ * related or neighboring rights to this work.  This work is published from:
+ * United States.
+ *
+ * Read a PNG and write it out in a fixed format, using the 'simplified API'
+ * that was introduced in libpng-1.6.0.
+ *
+ * This sample code is just the code from the top of 'example.c' with some error
+ * handling added.  See example.c for more comments.
+ */
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+/* Normally use <png.h> here to get the installed libpng, but this is done to
+ * ensure the code picks up the local libpng implementation:
+ */
+#include "../../png.h"
+
+int main(int argc, const char **argv)
+{
+   int result = 1;
+
+   if (argc == 3)
+   {
+      png_image image;
+
+      /* Only the image structure version number needs to be set. */
+      memset(&image, 0, sizeof image);
+      image.version = PNG_IMAGE_VERSION;
+
+      if (png_image_begin_read_from_file(&image, argv[1]))
+      {
+         png_bytep buffer;
+
+         /* Change this to try different formats!  If you set a colormap format
+          * then you must also supply a colormap below.
+          */
+         image.format = PNG_FORMAT_RGBA;
+
+         buffer = malloc(PNG_IMAGE_SIZE(image));
+
+         if (buffer != NULL)
+         {
+            if (png_image_finish_read(&image, NULL/*background*/, buffer,
+               0/*row_stride*/, NULL/*colormap for PNG_FORMAT_FLAG_COLORMAP */))
+            {
+               if (png_image_write_to_file(&image, argv[2],
+                  0/*convert_to_8bit*/, buffer, 0/*row_stride*/,
+                  NULL/*colormap*/))
+                  result = 0;
+
+               else
+                  fprintf(stderr, "pngtopng: write %s: %s\n", argv[2],
+                      image.message);
+
+               free(buffer);
+            }
+
+            else
+            {
+               fprintf(stderr, "pngtopng: read %s: %s\n", argv[1],
+                   image.message);
+
+               /* This is the only place where a 'free' is required; libpng does
+                * the cleanup on error and success, but in this case we couldn't
+                * complete the read because of running out of memory.
+                */
+               png_image_free(&image);
+            }
+         }
+
+         else
+            fprintf(stderr, "pngtopng: out of memory: %lu bytes\n",
+               (unsigned long)PNG_IMAGE_SIZE(image));
+      }
+
+      else
+         /* Failed to read the first argument: */
+         fprintf(stderr, "pngtopng: %s: %s\n", argv[1], image.message);
+   }
+
+   else
+      /* Wrong number of arguments */
+      fprintf(stderr, "pngtopng: usage: pngtopng input-file output-file\n");
+
+   return result;
+}
--- a/contrib/gregbook/COPYING
+++ b/contrib/gregbook/COPYING
@@ -1,12 +1,12 @@
-		    GNU GENERAL PUBLIC LICENSE
-		       Version 2, June 1991
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 2, June 1991

 Copyright (C) 1989, 1991 Free Software Foundation, Inc.
     59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

-			    Preamble
+                            Preamble

  The licenses for most software are designed to take away your
 freedom to share and change it.  By contrast, the GNU General Public
@@ -56,7 +56,7 @@ patent must be licensed for everyone's free use or not licensed at all.
  The precise terms and conditions for copying, distribution and
 modification follow.

-		    GNU GENERAL PUBLIC LICENSE
+                    GNU GENERAL PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. This License applies to any program or other work which contains
@@ -255,7 +255,7 @@ make exceptions for this.  Our decision will be guided by the two goals
 of preserving the free status of all derivatives of our free software and
 of promoting the sharing and reuse of software generally.

-			    NO WARRANTY
+                            NO WARRANTY

  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
 FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
@@ -277,9 +277,9 @@ YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
 PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGES.

-		     END OF TERMS AND CONDITIONS
+                     END OF TERMS AND CONDITIONS

-	    How to Apply These Terms to Your New Programs
+            How to Apply These Terms to Your New Programs

  If you develop a new program, and you want it to be of the greatest
 possible use to the public, the best way to achieve this is to make it
--- a/contrib/gregbook/LICENSE
+++ b/contrib/gregbook/LICENSE
@@ -1,6 +1,6 @@
  ---------------------------------------------------------------------------

-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.

      This software is provided "as is," without warranty of any kind,
      express or implied.  In no event shall the author or contributors
--- a/contrib/gregbook/Makefile.mingw32
+++ b/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 --------------------------------------------------------------
--- a/contrib/gregbook/Makefile.sgi
+++ b/contrib/gregbook/Makefile.sgi
@@ -23,9 +23,9 @@

 # macros --------------------------------------------------------------------

-PNGINC = -I/usr/local/include/libpng12
-PNGLIB = -L/usr/local/lib -lpng12	  # dynamically linked against libpng
-#PNGLIB = /usr/local/lib/libpng12.a # statically linked against libpng
+PNGINC = -I/usr/local/include/libpng16
+PNGLIB = -L/usr/local/lib -lpng16	  # dynamically linked against libpng
+#PNGLIB = /usr/local/lib/libpng16.a # statically linked against libpng
 # or:
 #PNGINC = -I../..
 #PNGLIB = -L../.. -lpng
@@ -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 --------------------------------------------------------------
--- a/contrib/gregbook/Makefile.unx
+++ b/contrib/gregbook/Makefile.unx
@@ -26,14 +26,14 @@
 # macros --------------------------------------------------------------------

 #PNGDIR = /usr/local/lib
-#PNGINC = -I/usr/local/include/libpng12
-#PNGLIBd = -L$(PNGDIR) -lpng12 # dynamically linked, installed libpng
-#PNGLIBs = $(PNGDIR)/libpng12.a # statically linked, installed libpng
+#PNGINC = -I/usr/local/include/libpng16
+#PNGLIBd = -L$(PNGDIR) -lpng16 # dynamically linked, installed libpng
+#PNGLIBs = $(PNGDIR)/libpng16.a # statically linked, installed libpng
 # or:
 PNGDIR = ../..#	this one is for libpng-x.y.z/contrib/gregbook builds
 #PNGDIR = ../libpng
 PNGINC = -I$(PNGDIR)
-PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng12	# dynamically linked
+PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng16	# dynamically linked
 PNGLIBs = $(PNGDIR)/libpng.a		# statically linked, local libpng

 ZDIR = /usr/local/lib
@@ -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 --------------------------------------------------------------
--- a/contrib/gregbook/Makefile.w32
+++ b/contrib/gregbook/Makefile.w32
@@ -18,7 +18,7 @@
 # "c:\windows\command.com /e:4096" as the program command line and set the
 # working directory to this directory.  Then double-click to open the new
 # DOS-prompt window with a bigger environment and retry the commands above.
-# 
+#
 # This makefile assumes libpng and zlib have already been built or downloaded
 # and are in subdirectories at the same level as the current subdirectory
 # (as indicated by the PNGPATH and ZPATH macros below).  Edit as appropriate.
@@ -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 --------------------------------------------------------------
--- a/contrib/gregbook/README
+++ b/contrib/gregbook/README
@@ -56,16 +56,16 @@ mation and links to the latest version of the source code, and Chapters

 Greg Roelofs
 http://pobox.com/~newt/greg_contact.html
-2 June 2007
+16 March 2008


 BUILD INSTRUCTIONS

 - Prerequisites (in order of compilation):

-      - zlib		http://zlib.net/
-      - libpng		http://www.libpng.org/pub/png/libpng.html
-      - pngbook		http://www.libpng.org/pub/png/book/sources.html
+      - zlib            http://zlib.net/
+      - libpng          http://www.libpng.org/pub/png/libpng.html
+      - pngbook         http://www.libpng.org/pub/png/book/sources.html

     The pngbook demo programs are explicitly designed to demonstrate proper
     coding techniques for using the libpng reference library.  As a result,
@@ -104,7 +104,7 @@ BUILD INSTRUCTIONS
     unpacked the source code.

     For MSVC, set up the necessary environment variables by invoking
- 
+
        %devstudio%\vc\bin\vcvars32.bat

     where where %devstudio% is the installation directory for MSVC /
@@ -165,19 +165,19 @@ RUNNING THE PROGRAMS:  (VERY) BRIEF INTRO
     rpng is a simple PNG viewer that can display transparent PNGs with a
     specified background color; for example,

-	rpng -bgcolor #ff0000 toucan.png
+        rpng -bgcolor \#ff0000 toucan.png

     would display the image with a red background.  rpng2 is a progressive
     viewer that simulates a web browser in some respects; it can display
     images against either a background color or a dynamically generated
     background image.  For example:

-	rpng2 -bgpat 16 toucan.png
+        rpng2 -bgpat 16 toucan.png

     wpng is a purely command-line image converter from binary PBMPLUS/NetPBM
     format (.pgm or .ppm) to PNG; for example,

-	wpng -time < toucan-notrans.ppm > toucan-notrans.png
+        wpng -time < toucan-notrans.ppm > toucan-notrans.png

     would convert the specified PPM file (using redirection) to PNG, auto-
     matically setting the PNG modification-time chunk.
--- a/contrib/gregbook/makevms.com
+++ b/contrib/gregbook/makevms.com
@@ -20,13 +20,13 @@ $ if zpath .eqs. ""
 $ then
 $   write sys$output "zlib include not found. Exiting..."
 $   exit 2
-$ endif 
+$ endif
 $!
 $ if pngpath .eqs. ""
 $ then
 $   write sys$output "libpng include not found. Exiting..."
 $   exit 2
-$ endif 
+$ endif
 $!
 $!    Look for the compiler used.
 $!
--- a/contrib/gregbook/readpng.c
+++ b/contrib/gregbook/readpng.c
@@ -55,8 +55,9 @@

 #include <stdio.h>
 #include <stdlib.h>
+#include <zlib.h>

-#include "png.h"        /* libpng header; includes zlib.h */
+#include "png.h"        /* libpng header */
 #include "readpng.h"    /* typedefs, common macros, public prototypes */

 /* future versions of libpng will provide this macro: */
@@ -93,13 +94,14 @@ int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
     * have used slightly more general png_sig_cmp() function instead */

    fread(sig, 1, 8, infile);
-    if (!png_check_sig(sig, 8))
+    if (png_sig_cmp(sig, 0, 8))
        return 1;   /* bad signature */


    /* 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 */

@@ -214,6 +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;
    }
@@ -229,8 +235,14 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
        png_set_expand(png_ptr);
    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
        png_set_expand(png_ptr);
+#ifdef PNG_READ_16_TO_8_SUPPORTED
    if (bit_depth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
        png_set_strip_16(png_ptr);
+#  endif
+#endif
    if (color_type == PNG_COLOR_TYPE_GRAY ||
        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
        png_set_gray_to_rgb(png_ptr);
@@ -263,7 +275,8 @@ uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
        return NULL;
    }

-    Trace((stderr, "readpng_get_image:  channels = %d, rowbytes = %ld, height = %ld\n", *pChannels, rowbytes, height));
+    Trace((stderr, "readpng_get_image:  channels = %d, rowbytes = %ld, height = %ld\n",
+        *pChannels, rowbytes, height));


    /* set the individual row_pointers to point at the correct offsets */
--- a/contrib/gregbook/readpng2.c
+++ b/contrib/gregbook/readpng2.c
@@ -55,8 +55,10 @@


 #include <stdlib.h>     /* for exit() prototype */
+#include <setjmp.h>

-#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include <zlib.h>
+#include "png.h"        /* libpng header from the local directory */
 #include "readpng2.h"   /* typedefs, common macros, public prototypes */


@@ -67,90 +69,17 @@ 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);




 void readpng2_version_info(void)
 {
-#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && \
-    (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
-    defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
-    /*
-     * WARNING:  This preprocessor approach means that the following code
-     *           cannot be used with a libpng DLL older than 1.2.0--the
-     *           compiled-in symbols for the new functions will not exist.
-     *           (Could use dlopen() and dlsym() on Unix and corresponding
-     *           calls for Windows, but not portable...)
-     */
-    {
-        int mmxsupport = png_mmx_support();
-        if (mmxsupport < 0)
-            fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
-              "without MMX support.\n", PNG_LIBPNG_VER_STRING, png_libpng_ver);
-        else {
-            int compilerID;
-            png_uint_32 mmx_mask = png_get_mmx_flagmask(
-              PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s\n",
+      PNG_LIBPNG_VER_STRING, png_libpng_ver);

-            fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
-              "with MMX support\n   (%s version).", PNG_LIBPNG_VER_STRING,
-              png_libpng_ver, compilerID == 1? "MSVC++" :
-              (compilerID == 2? "GNU C" : "unknown"));
-            fprintf(stderr, "  Processor (x86%s) %s MMX instructions.\n",
-#if defined(__x86_64__)
-              "_64",
-#else
-              "",
-#endif
-              mmxsupport? "supports" : "does not support");
-            if (mmxsupport > 0) {
-                int num_optims = 0;
-
-                fprintf(stderr,
-                  "      Potential MMX optimizations supported by libpng:\n");
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_SUB)
-                    ++num_optims;
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_UP)
-                    ++num_optims;
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_AVG)
-                    ++num_optims;
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH)
-                    ++num_optims;
-                if (num_optims)
-                    fprintf(stderr,
-                      "         decoding %s row filters (reading)\n",
-                      (num_optims == 4)? "all non-trivial" : "some");
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW) {
-                    fprintf(stderr, "         combining rows (reading)\n");
-                    ++num_optims;
-                }
-                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_INTERLACE) {
-                    fprintf(stderr,
-                      "         expanding interlacing (reading)\n");
-                    ++num_optims;
-                }
-                mmx_mask &= ~( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
-                             | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
-                             | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
-                             | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
-                             | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
-                             | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
-                if (mmx_mask) {
-                    fprintf(stderr, "         other (unknown)\n");
-                    ++num_optims;
-                }
-                if (num_optims == 0)
-                    fprintf(stderr, "         (none)\n");
-            }
-        }
-    }
-#else
-    fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
-      "without MMX support.\n", PNG_LIBPNG_VER_STRING, png_libpng_ver);
-#endif
-
-    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+    fprintf(stderr, "   and with zlib %s; using zlib %s.\n",
      ZLIB_VERSION, zlib_version);
 }

@@ -159,7 +88,7 @@ void readpng2_version_info(void)

 int readpng2_check_sig(uch *sig, int num)
 {
-    return png_check_sig(sig, num);
+    return !png_sig_cmp(sig, 0, num);
 }


@@ -175,8 +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 */

@@ -203,36 +132,30 @@ int readpng2_init(mainprog_info *mainprog_ptr)
    }


-#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
    /* prepare the reader to ignore all recognized chunks whose data won't be
     * 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_UNKNOWN_CHUNKS_SUPPORTED */
+#endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */


    /* instead of doing png_init_io() here, now we set up our callback
@@ -242,96 +165,6 @@ int readpng2_init(mainprog_info *mainprog_ptr)
      readpng2_info_callback, readpng2_row_callback, readpng2_end_callback);


-    /*
-     * may as well enable or disable MMX routines here, if supported;
-     *
-     * to enable all:  mask = png_get_mmx_flagmask (
-     *                   PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
-     *                 flags = png_get_asm_flags (png_ptr);
-     *                 flags |= mask;
-     *                 png_set_asm_flags (png_ptr, flags);
-     *
-     * to disable all:  mask = png_get_mmx_flagmask (
-     *                   PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
-     *                  flags = png_get_asm_flags (png_ptr);
-     *                  flags &= ~mask;
-     *                  png_set_asm_flags (png_ptr, flags);
-     */
-
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
-    defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
-    /*
-     * WARNING:  This preprocessor approach means that the following code
-     *           cannot be used with a libpng DLL older than 1.2.0--the
-     *           compiled-in symbols for the new functions will not exist.
-     *           (Could use dlopen() and dlsym() on Unix and corresponding
-     *           calls for Windows, but not portable...)
-     */
-    {
-#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
-        png_uint_32 mmx_disable_mask = 0;
-        png_uint_32 asm_flags, mmx_mask;
-        int compilerID;
-
-        if (mainprog_ptr->nommxfilters)
-            mmx_disable_mask |= ( PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
-                                | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
-                                | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
-                                | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
-        if (mainprog_ptr->nommxcombine)
-            mmx_disable_mask |= PNG_ASM_FLAG_MMX_READ_COMBINE_ROW;
-        if (mainprog_ptr->nommxinterlace)
-            mmx_disable_mask |= PNG_ASM_FLAG_MMX_READ_INTERLACE;
-        asm_flags = png_get_asm_flags(png_ptr);
-        png_set_asm_flags(png_ptr, asm_flags & ~mmx_disable_mask);
-
-
-        /* Now query libpng's asm settings, just for yuks.  Note that this
-         * differs from the querying of its *potential* MMX capabilities
-         * in readpng2_version_info(); this is true runtime verification. */
-
-        asm_flags = png_get_asm_flags(png_ptr);
-        mmx_mask = png_get_mmx_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE,
-          &compilerID);
-        if (asm_flags & PNG_ASM_FLAG_MMX_SUPPORT_COMPILED)
-            fprintf(stderr,
-              "  MMX support (%s version) is compiled into libpng\n",
-              compilerID == 1? "MSVC++" :
-              (compilerID == 2? "GNU C" : "unknown"));
-        else
-            fprintf(stderr, "  MMX support is not compiled into libpng\n");
-        fprintf(stderr, "  MMX instructions are %ssupported by CPU\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU)? "" : "not ");
-        fprintf(stderr, "  MMX read support for combining rows is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)? "en" : "dis");
-        fprintf(stderr,
-          "  MMX read support for expanding interlacing is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_INTERLACE)? "en" : "dis");
-        fprintf(stderr, "  MMX read support for \"sub\" filter is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_SUB)? "en" : "dis");
-        fprintf(stderr, "  MMX read support for \"up\" filter is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_UP)? "en" : "dis");
-        fprintf(stderr, "  MMX read support for \"avg\" filter is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_AVG)? "en" : "dis");
-        fprintf(stderr, "  MMX read support for \"Paeth\" filter is %sabled\n",
-          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH)? "en" : "dis");
-        asm_flags &= (mmx_mask & ~( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
-                                  | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
-                                  | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
-                                  | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
-                                  | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
-                                  | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ));
-        if (asm_flags)
-            fprintf(stderr,
-              "  additional MMX support is also enabled (0x%02lx)\n",
-              asm_flags);
-#else  /* !PNG_ASSEMBLER_CODE_SUPPORTED */
-        fprintf(stderr, "  MMX querying is disabled in libpng.\n");
-#endif /* ?PNG_ASSEMBLER_CODE_SUPPORTED */
-    }
-#endif
-
-
    /* make sure we save our pointers for use in readpng2_decode_data() */

    mainprog_ptr->png_ptr = png_ptr;
@@ -379,7 +212,12 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
 {
    mainprog_info  *mainprog_ptr;
    int  color_type, bit_depth;
+    png_uint_32 width, height;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
    double  gamma;
+#else
+    png_fixed_point gamma;
+#endif


    /* setjmp() doesn't make sense here, because we'd either have to exit(),
@@ -414,8 +252,10 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)

    /* this is just like in the non-progressive case */

-    png_get_IHDR(png_ptr, info_ptr, &mainprog_ptr->width,
-      &mainprog_ptr->height, &bit_depth, &color_type, NULL, NULL, NULL);
+    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+       NULL, NULL, NULL);
+    mainprog_ptr->width = (ulg)width;
+    mainprog_ptr->height = (ulg)height;


    /* since we know we've read all of the PNG file's "header" (i.e., up
@@ -466,8 +306,14 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
        png_set_expand(png_ptr);
    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
        png_set_expand(png_ptr);
+#ifdef PNG_READ_16_TO_8_SUPPORTED
    if (bit_depth == 16)
+#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+        png_set_scale_16(png_ptr);
+#  else
        png_set_strip_16(png_ptr);
+#  endif
+#endif
    if (color_type == PNG_COLOR_TYPE_GRAY ||
        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
        png_set_gray_to_rgb(png_ptr);
@@ -488,11 +334,19 @@ static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
     * "gamma" value for the entire display system, i.e., the product of
     * LUT_exponent and CRT_exponent. */

+#ifdef PNG_FLOATING_POINT_SUPPORTED
    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, gamma);
    else
        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, 0.45455);
-
+#else
+    if (png_get_gAMA_fixed(png_ptr, info_ptr, &gamma))
+        png_set_gamma_fixed(png_ptr,
+            (png_fixed_point)(100000*mainprog_ptr->display_exponent+.5), gamma);
+    else
+        png_set_gamma_fixed(png_ptr,
+            (png_fixed_point)(100000*mainprog_ptr->display_exponent+.5), 45455);
+#endif

    /* we'll let libpng expand interlaced images, too */

@@ -594,6 +448,8 @@ static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr)

    /* all done */

+    (void)info_ptr; /* Unused */
+
    return;
 }

@@ -614,7 +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)
@@ -641,5 +502,12 @@ static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)
        exit(99);
    }

+    /* Now we have our data structure we can use the information in it
+     * to return control to our own higher level code (all the points
+     * where 'setjmp' is called in this file.)  This will work with other
+     * error handling mechanisms as well - libpng always calls png_error
+     * when it can proceed no further, thus, so long as the error handler
+     * is intercepted, application code can do its own error recovery.
+     */
    longjmp(mainprog_ptr->jmpbuf, 1);
 }
--- a/contrib/gregbook/readpng2.h
+++ b/contrib/gregbook/readpng2.h
@@ -4,7 +4,7 @@

  ---------------------------------------------------------------------------

-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.

      This software is provided "as is," without warranty of any kind,
      express or implied.  In no event shall the author or contributors
@@ -69,6 +69,12 @@
 #  define Trace(x)  ;
 #endif

+enum rpng2_states {
+    kPreInit = 0,
+    kWindowInit,
+    kDone
+};
+
 typedef unsigned char   uch;
 typedef unsigned short  ush;
 typedef unsigned long   ulg;
@@ -90,12 +96,7 @@ typedef struct _mainprog_info {
    int rowbytes;
    int channels;
    int need_bgcolor;
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-    int nommxfilters;
-    int nommxcombine;
-    int nommxinterlace;
-#endif
-    int done;
+    int state;
    uch bg_red;
    uch bg_green;
    uch bg_blue;
--- a/contrib/gregbook/readppm.c
+++ b/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;
 }
--- a/contrib/gregbook/rpng-win.c
+++ b/contrib/gregbook/rpng-win.c
@@ -23,10 +23,11 @@
              command-line parsing bug
    - 1.10:  enabled "message window"/console (thanks to David Geldreich)
    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed improper display of usage screen on PNG error(s)

  ---------------------------------------------------------------------------

-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.

      This software is provided "as is," without warranty of any kind,
      express or implied.  In no event shall the author or contributors
@@ -77,14 +78,40 @@

 #define PROGNAME  "rpng-win"
 #define LONGNAME  "Simple PNG Viewer for Windows"
-#define VERSION   "2.00 of 2 June 2007"
+#define VERSION   "2.01 of 16 March 2008"

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <windows.h>
+#ifdef __CYGWIN__
+/* getch replacement. Turns out, we don't really need this,
+ * but leave it here if we ever enable any of the uses of
+ * _getch in the main code
+ */
+#include <unistd.h>
+#include <termio.h>
+#include <sys/ioctl.h>
+int repl_getch( void )
+{
+  char ch;
+  int fd = fileno(stdin);
+  struct termio old_tty, new_tty;
+
+  ioctl(fd, TCGETA, &old_tty);
+  new_tty = old_tty;
+  new_tty.c_lflag &= ~(ICANON | ECHO | ISIG);
+  ioctl(fd, TCSETA, &new_tty);
+  fread(&ch, 1, sizeof(ch), stdin);
+  ioctl(fd, TCSETA, &old_tty);
+
+  return ch;
+}
+#define _getch repl_getch
+#else
 #include <conio.h>      /* only for _getch() */
+#endif

 /* #define DEBUG  :  this enables the Trace() macros */

@@ -152,7 +179,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)

    filename = (char *)NULL;

-
+#ifndef __CYGWIN__
    /* First reenable console output, which normally goes to the bit bucket
     * for windowed apps.  Closing the console window will terminate the
     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
@@ -161,6 +188,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
    AllocConsole();
    freopen("CONOUT$", "a", stderr);
    freopen("CONOUT$", "a", stdout);
+#endif


    /* Next set the default value for our display-system exponent, i.e.,
@@ -271,9 +299,43 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
        }
    }

-    if (!filename) {
+    if (!filename)
        ++error;
-    } else if (!(infile = fopen(filename, "rb"))) {
+
+
+    /* print usage screen if any errors up to this point */
+
+    if (error) {
+#ifndef __CYGWIN__
+        int ch;
+#endif
+
+        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-gamma exp] [-bgcolor bg] file.png\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  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 after image is displayed to quit.\n"
+#ifndef __CYGWIN__
+          "Press Q or Esc to quit this usage screen.\n"
+#endif
+          "\n", PROGNAME, default_display_exponent);
+#ifndef __CYGWIN__
+        do
+            ch = _getch();
+        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
+#endif
+        exit(1);
+    }
+
+
+    if (!(infile = fopen(filename, "rb"))) {
        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
        ++error;
    } else {
@@ -286,8 +348,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
                    break;
                case 2:
                    fprintf(stderr, PROGNAME
-                      ":  [%s] has bad IHDR (libpng longjmp)\n",
-                      filename);
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
                    break;
                case 4:
                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
@@ -304,34 +365,25 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
    }


-    /* usage screen */
-
    if (error) {
+#ifndef __CYGWIN__
        int ch;
+#endif

-        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
-        readpng_version_info();
-        fprintf(stderr, "\n"
-          "Usage:  %s [-gamma exp] [-bgcolor bg] file.png\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  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 after image is displayed to quit.\n"
-          "Press Q or Esc to quit this usage screen.\n"
-          "\n", PROGNAME, default_display_exponent);
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+#ifndef __CYGWIN__
        do
            ch = _getch();
        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
-        exit(1);
+#endif
+        exit(2);
    } else {
        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+#ifndef __CYGWIN__
        fprintf(stderr,
          "\n   [console window:  closing this window will terminate %s]\n\n",
          PROGNAME);
+#endif
    }


@@ -404,7 +456,12 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
    /* wait for the user to tell us when to quit */

    printf(
-      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+#ifndef __CYGWIN__
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n"
+#else
+      "Done.  Press mouse button 1 (within image window) to quit.\n"
+#endif
+    );
    fflush(stdout);

    while (GetMessage(&msg, NULL, 0, 0)) {
--- a/contrib/gregbook/rpng-x.c
+++ b/contrib/gregbook/rpng-x.c
@@ -25,10 +25,13 @@
    - 1.13:  fixed XFreeGC() crash bug (thanks to Patrick Welche)
    - 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)

  ---------------------------------------------------------------------------

-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.

      This software is provided "as is," without warranty of any kind,
      express or implied.  In no event shall the author or contributors
@@ -79,9 +82,9 @@

 #define PROGNAME  "rpng-x"
 #define LONGNAME  "Simple PNG Viewer for X"
-#define VERSION   "2.00 of 2 June 2007"
-#define RESNAME   "rpng"	/* our X resource application name */
-#define RESCLASS  "Rpng"	/* our X resource class name */
+#define VERSION   "2.02 of 15 June 2014"
+#define RESNAME   "rpng"        /* our X resource application name */
+#define RESCLASS  "Rpng"        /* our X resource class name */

 #include <stdio.h>
 #include <stdlib.h>
@@ -251,8 +254,8 @@ int main(int argc, char **argv)
            else {
                bgstr = *argv;
                if (strlen(bgstr) != 7 || bgstr[0] != '#')
-                    ++error; 
-                else 
+                    ++error;
+                else
                    have_bg = TRUE;
            }
        } else {
@@ -265,9 +268,35 @@ int main(int argc, char **argv)
        }
    }

-    if (!filename) {
+    if (!filename)
        ++error;
-    } else if (!(infile = fopen(filename, "rb"))) {
+
+
+    /* print usage screen if any errors up to this point */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
+          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n",
+          PROGNAME, default_display_exponent);
+
+        fprintf(stderr, "\n"
+          "\t\t  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");
+        exit(1);
+    }
+
+
+    if (!(infile = fopen(filename, "rb"))) {
        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
        ++error;
    } else {
@@ -280,8 +309,7 @@ int main(int argc, char **argv)
                    break;
                case 2:
                    fprintf(stderr, PROGNAME
-                      ":  [%s] has bad IHDR (libpng longjmp)\n",
-                      filename);
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
                    break;
                case 4:
                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
@@ -306,25 +334,9 @@ int main(int argc, char **argv)
    }


-    /* usage screen */
-
    if (error) {
-        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
-        readpng_version_info();
-        fprintf(stderr, "\n"
-          "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  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);
-        exit(1);
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+        exit(2);
    }


@@ -411,6 +423,8 @@ int main(int argc, char **argv)

    rpng_x_cleanup();

+    (void)argc; /* Unused */
+
    return 0;
 }

--- a/contrib/gregbook/rpng2-win.c
+++ b/contrib/gregbook/rpng2-win.c
@@ -10,7 +10,7 @@
   tweaking (or maybe not).  Thanks to Adam Costello and Pieter S. van der
   Meulen for the "diamond" and "radial waves" patterns, respectively.

-   to do:
+   to do (someday, maybe):
    - handle quoted command-line args (especially filenames with spaces)
    - finish resizable checkerboard-gradient (sizes 4-128?)
    - use %.1023s to simplify truncation of title-bar string?
@@ -29,10 +29,16 @@
    - 1.21:  made minor tweak to usage screen to fit within 25-line console
    - 1.22:  added AMD64/EM64T support (__x86_64__)
    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed 64-bit typo in readpng2.c
+    - 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)

  ---------------------------------------------------------------------------

-      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.

      This software is provided "as is," without warranty of any kind,
      express or implied.  In no event shall the author or contributors
@@ -83,7 +89,7 @@

 #define PROGNAME  "rpng2-win"
 #define LONGNAME  "Progressive PNG Viewer for Windows"
-#define VERSION   "2.00 of 2 June 2007"
+#define VERSION   "2.02 of 16 March 2008"

 #include <stdio.h>
 #include <stdlib.h>
@@ -92,7 +98,33 @@
 #include <time.h>
 #include <math.h>      /* only for PvdM background code */
 #include <windows.h>
+#ifdef __CYGWIN__
+/* getch replacement. Turns out, we don't really need this,
+ * but leave it here if we ever enable any of the uses of
+ * _getch in the main code
+ */
+#include <unistd.h>
+#include <termio.h>
+#include <sys/ioctl.h>
+int repl_getch( void )
+{
+  char ch;
+  int fd = fileno(stdin);
+  struct termio old_tty, new_tty;
+
+  ioctl(fd, TCGETA, &old_tty);
+  new_tty = old_tty;
+  new_tty.c_lflag &= ~(ICANON | ECHO | ISIG);
+  ioctl(fd, TCSETA, &new_tty);
+  fread(&ch, 1, sizeof(ch), stdin);
+  ioctl(fd, TCSETA, &old_tty);
+
+  return ch;
+}
+#define _getch repl_getch
+#else
 #include <conio.h>     /* only for _getch() */
+#endif

 /* all for PvdM background code: */
 #ifndef PI
@@ -266,7 +298,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
    filename = (char *)NULL;
    memset(&rpng2_info, 0, sizeof(mainprog_info));

-
+#ifndef __CYGWIN__
    /* Next reenable console output, which normally goes to the bit bucket
     * for windowed apps.  Closing the console window will terminate the
     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
@@ -275,7 +307,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
    AllocConsole();
    freopen("CONOUT$", "a", stderr);
    freopen("CONOUT$", "a", stdout);
-
+#endif

    /* Set the default value for our display-system exponent, i.e., the
     * product of the CRT exponent and the exponent corresponding to
@@ -392,18 +424,6 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
            }
        } else if (!strncmp(*argv, "-timing", 2)) {
            timing = TRUE;
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-        } else if (!strncmp(*argv, "-nommxfilters", 7)) {
-            rpng2_info.nommxfilters = TRUE;
-        } else if (!strncmp(*argv, "-nommxcombine", 7)) {
-            rpng2_info.nommxcombine = TRUE;
-        } else if (!strncmp(*argv, "-nommxinterlace", 7)) {
-            rpng2_info.nommxinterlace = TRUE;
-        } else if (!strcmp(*argv, "-nommx")) {
-            rpng2_info.nommxfilters = TRUE;
-            rpng2_info.nommxcombine = TRUE;
-            rpng2_info.nommxinterlace = TRUE;
-#endif
        } else {
            if (**argv != '-') {
                filename = *argv;
@@ -414,9 +434,56 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
        }
    }

-    if (!filename) {
+    if (!filename)
        ++error;
-    } else if (!(infile = fopen(filename, "rb"))) {
+
+
+    /* print usage screen if any errors up to this point */
+
+    if (error) {
+#ifndef __CYGWIN__
+        int ch;
+#endif
+
+        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
+        readpng2_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-gamma exp] [-bgcolor bg | -bgpat pat] [-timing]\n"
+          "        %*s file.png\n\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  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 option\n"
+          "    pat \tdesired background pattern number (1-%d); used with\n"
+          "\t\t  transparent images; overrides -bgcolor option\n"
+          "    -timing\tenables delay for every block read, to simulate modem\n"
+          "\t\t  download of image (~36 Kbps)\n"
+          "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
+#ifndef __CYGWIN__
+          "Press Q or Esc to quit this usage screen. ",
+#else
+          ,
+#endif
+          PROGNAME,
+#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
+    !(defined(__CYGWIN__) || defined(__MINGW32__))
+          (int)strlen(PROGNAME), " ",
+#endif
+          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat);
+        fflush(stderr);
+#ifndef __CYGWIN__
+        do
+            ch = _getch();
+        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
+#endif
+        exit(1);
+    }
+
+
+    if (!(infile = fopen(filename, "rb"))) {
        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
        ++error;
    } else {
@@ -430,8 +497,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
            switch (rc) {
                case 2:
                    fprintf(stderr, PROGNAME
-                      ":  [%s] has bad IHDR (libpng longjmp)\n",
-                      filename);
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
                    break;
                case 4:
                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
@@ -448,51 +514,25 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
    }


-    /* usage screen */
-
    if (error) {
+#ifndef __CYGWIN__
        int ch;
+#endif

-        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
-        readpng2_version_info();
-        fprintf(stderr, "\n"
-          "Usage:  %s [-gamma exp] [-bgcolor bg | -bgpat pat] [-timing]\n"
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          "        %*s [[-nommxfilters] [-nommxcombine] [-nommxinterlace] | -nommx]\n"
-#endif
-          "        %*s file.png\n\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  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 option\n"
-          "    pat \tdesired background pattern number (1-%d); used with\n"
-          "\t\t  transparent images; overrides -bgcolor option\n"
-          "    -timing\tenables delay for every block read, to simulate modem\n"
-          "\t\t  download of image (~36 Kbps)\n"
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          "    -nommx*\tdisable optimized MMX routines for decoding row filters,\n"
-          "\t\t  combining rows, and expanding interlacing, respectively\n"
-#endif
-          "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
-          "Press Q or Esc to quit this usage screen. ",
-          PROGNAME,
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          (int)strlen(PROGNAME), " ",
-#endif
-          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat);
-        fflush(stderr);
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+#ifndef __CYGWIN__
        do
            ch = _getch();
        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
-        exit(1);
+#endif
+        exit(2);
    } else {
        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+#ifndef __CYGWIN__
        fprintf(stderr,
          "\n   [console window:  closing this window will terminate %s]\n\n",
          PROGNAME);
+#endif
        fflush(stderr);
    }

@@ -519,7 +559,7 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
    } else
        rpng2_info.need_bgcolor = TRUE;

-    rpng2_info.done = FALSE;
+    rpng2_info.state = kPreInit;
    rpng2_info.mainprog_init = rpng2_win_init;
    rpng2_info.mainprog_display_row = rpng2_win_display_row;
    rpng2_info.mainprog_finish_display = rpng2_win_finish_display;
@@ -539,10 +579,27 @@ int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
        if (readpng2_decode_data(&rpng2_info, inbuf, incount))
            ++error;
        Trace((stderr, "done with readpng2_decode_data()\n"))
-        if (error || feof(infile) || rpng2_info.done)
+
+        if (error || incount != INBUFSIZE || rpng2_info.state == kDone) {
+            if (rpng2_info.state == kDone) {
+                Trace((stderr, "done decoding PNG image\n"))
+            } else if (ferror(infile)) {
+                fprintf(stderr, PROGNAME
+                  ":  error while reading PNG image file\n");
+                exit(3);
+            } else if (feof(infile)) {
+                fprintf(stderr, PROGNAME ":  end of file reached "
+                  "(unexpectedly) while reading PNG image file\n");
+                exit(3);
+            } else /* if (error) */ {
+                /* will print error message below */
+            }
            break;
+        }
+
        if (timing)
            Sleep(1000L);
+
        incount = fread(inbuf, 1, INBUFSIZE, infile);
    }

@@ -589,7 +646,7 @@ static void rpng2_win_init()
    ulg rowbytes = rpng2_info.rowbytes;

    Trace((stderr, "beginning rpng2_win_init()\n"))
-    Trace((stderr, "  rowbytes = %ld\n", rpng2_info.rowbytes))
+    Trace((stderr, "  rowbytes = %d\n", rpng2_info.rowbytes))
    Trace((stderr, "  width  = %ld\n", rpng2_info.width))
    Trace((stderr, "  height = %ld\n", rpng2_info.height))

@@ -619,6 +676,8 @@ static void rpng2_win_init()
        readpng2_cleanup(&rpng2_info);
        return;
    }
+
+    rpng2_info.state = kWindowInit;
 }


@@ -1114,9 +1173,14 @@ static void rpng2_win_finish_display()
     * we have nothing to do here except set a flag and let the user know
     * that the image is done */

-    rpng2_info.done = TRUE;
+    rpng2_info.state = kDone;
    printf(
-      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+#ifndef __CYGWIN__
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n"
+#else
+      "Done.  Press mouse button 1 (within image window) to quit.\n"
+#endif
+    );
    fflush(stdout);
 }

--- a/contrib/gregbook/rpng2-x.c
+++ b/contrib/gregbook/rpng2-x.c
@@ -12,7 +12,7 @@
   Thanks to Adam Costello and Pieter S. van der Meulen for the "diamond"
   and "radial waves" patterns, respectively.

-   to do:
+   to do (someday, maybe):
    - fix expose/redraw code:  don't draw entire row if only part exposed
    - 8-bit (colormapped) X support
    - finish resizable checkerboard-gradient (sizes 4-128?)
@@ -36,10 +36,19 @@
    - 1.32:  added AMD64/EM64T support (__x86_64__); added basic expose/redraw
              handling
    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed 64-bit typo in readpng2.c; fixed -pause usage description
+    - 2.02:  fixed improper display of usage screen on PNG error(s); fixed
+              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) 1998-2007 Greg Roelofs.  All rights reserved.
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.

      This software is provided "as is," without warranty of any kind,
      express or implied.  In no event shall the author or contributors
@@ -90,9 +99,9 @@

 #define PROGNAME  "rpng2-x"
 #define LONGNAME  "Progressive PNG Viewer for X"
-#define VERSION   "2.00 of 2 June 2007"
-#define RESNAME   "rpng2"	/* our X resource application name */
-#define RESCLASS  "Rpng"	/* our X resource class name */
+#define VERSION   "2.04 of 15 June 2014"
+#define RESNAME   "rpng2"       /* our X resource application name */
+#define RESCLASS  "Rpng"       /* our X resource class name */

 #include <stdio.h>
 #include <stdlib.h>
@@ -106,6 +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
@@ -127,7 +148,7 @@
                  (e.type == KeyPress &&   /*  v--- or 1 for shifted keys */  \
                  ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape)))

-#define NO_24BIT_MASKS	/* undef case not fully written--only for redisplay() */
+#define NO_24BIT_MASKS /* undef case not fully written--only for redisplay() */

 #define rgb1_max   bg_freq
 #define rgb1_min   bg_gray
@@ -297,7 +318,7 @@ int main(int argc, char **argv)
    int have_bg = FALSE;
 #ifdef FEATURE_LOOP
    int loop = FALSE;
-    long loop_interval = -1;		/* seconds (100,000 max) */
+    long loop_interval = -1;            /* seconds (100,000 max) */
 #endif
    double LUT_exponent;                /* just the lookup table */
    double CRT_exponent = 2.2;          /* just the monitor */
@@ -430,18 +451,6 @@ int main(int argc, char **argv)
                else if (loop_interval > 100000)   /* bit more than one day */
                    loop_interval = 100000;
            }
-#endif
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-        } else if (!strncmp(*argv, "-nommxfilters", 7)) {
-            rpng2_info.nommxfilters = TRUE;
-        } else if (!strncmp(*argv, "-nommxcombine", 7)) {
-            rpng2_info.nommxcombine = TRUE;
-        } else if (!strncmp(*argv, "-nommxinterlace", 7)) {
-            rpng2_info.nommxinterlace = TRUE;
-        } else if (!strcmp(*argv, "-nommx")) {
-            rpng2_info.nommxfilters = TRUE;
-            rpng2_info.nommxcombine = TRUE;
-            rpng2_info.nommxinterlace = TRUE;
 #endif
        } else {
            if (**argv != '-') {
@@ -453,9 +462,58 @@ int main(int argc, char **argv)
        }
    }

-    if (!filename) {
+    if (!filename)
        ++error;
-    } else if (!(infile = fopen(filename, "rb"))) {
+
+
+    /* print usage screen if any errors up to this point */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
+        readpng2_version_info();
+        fprintf(stderr, "\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
+          "        [-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",
+          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",
+          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");
+#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");
+        exit(1);
+    }
+
+    if (!(infile = fopen(filename, "rb"))) {
        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
        ++error;
    } else {
@@ -469,8 +527,7 @@ int main(int argc, char **argv)
            switch (rc) {
                case 2:
                    fprintf(stderr, PROGNAME
-                      ":  [%s] has bad IHDR (libpng longjmp)\n",
-                      filename);
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
                    break;
                case 4:
                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
@@ -482,6 +539,7 @@ int main(int argc, char **argv)
            }
            ++error;
        } else {
+            Trace((stderr, "about to call XOpenDisplay()\n"))
            display = XOpenDisplay(displayname);
            if (!display) {
                readpng2_cleanup(&rpng2_info);
@@ -495,53 +553,9 @@ int main(int argc, char **argv)
    }


-    /* usage screen */
-
    if (error) {
-        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"
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          "        %*s [[-nommxfilters] [-nommxcombine] [-nommxinterlace] | -nommx]\n"
-#endif
-#ifdef FEATURE_LOOP
-          "        %*s [-usleep dur | -timing] [-pause] [-loop [sec]] file.png\n\n"
-#else
-          "        %*s [-usleep dur | -timing] [-pause] file.png\n\n"
-#endif
-          "    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  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"
-#ifdef FEATURE_LOOP
-          "    -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"
-#endif
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          "    -nommx*\tdisable optimized MMX routines for decoding row filters,\n"
-          "\t\t  combining rows, and expanding interlacing, respectively\n"
-#endif
-          "    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 key pressed\n"
-          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
-          "is displayed) to quit.\n"
-          "\n", PROGNAME,
-#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
-          (int)strlen(PROGNAME), " ",
-#endif
-          (int)strlen(PROGNAME), " ", default_display_exponent, num_bgpat-1);
-        exit(1);
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+        exit(2);
    }


@@ -567,7 +581,7 @@ int main(int argc, char **argv)
    } else
        rpng2_info.need_bgcolor = TRUE;

-    rpng2_info.done = FALSE;
+    rpng2_info.state = kPreInit;
    rpng2_info.mainprog_init = rpng2_x_init;
    rpng2_info.mainprog_display_row = rpng2_x_display_row;
    rpng2_info.mainprog_finish_display = rpng2_x_finish_display;
@@ -587,10 +601,27 @@ int main(int argc, char **argv)
        if (readpng2_decode_data(&rpng2_info, inbuf, incount))
            ++error;
        Trace((stderr, "done with readpng2_decode_data()\n"))
-        if (error || feof(infile) || rpng2_info.done)
+
+        if (error || incount != INBUFSIZE || rpng2_info.state == kDone) {
+            if (rpng2_info.state == kDone) {
+                Trace((stderr, "done decoding PNG image\n"))
+            } else if (ferror(infile)) {
+                fprintf(stderr, PROGNAME
+                  ":  error while reading PNG image file\n");
+                exit(3);
+            } else if (feof(infile)) {
+                fprintf(stderr, PROGNAME ":  end of file reached "
+                  "(unexpectedly) while reading PNG image file\n");
+                exit(3);
+            } else /* if (error) */ {
+                /* will print error message below */
+            }
            break;
+        }
+
        if (timing)
            sleep(1);
+
        incount = fread(inbuf, 1, INBUFSIZE, infile);
    }

@@ -610,6 +641,7 @@ int main(int argc, char **argv)
 #ifdef FEATURE_LOOP

    if (loop && bg_image) {
+        Trace((stderr, "entering -loop loop (FEATURE_LOOP)\n"))
        for (;;) {
            int i, use_sleep;
            struct timeval now, then;
@@ -705,13 +737,20 @@ int main(int argc, char **argv)

    /* wait for the user to tell us when to quit */

-    do {
-        XNextEvent(display, &e);
-        if (e.type == Expose) {
-            XExposeEvent *ex = (XExposeEvent *)&e;
-            rpng2_x_redisplay_image (ex->x, ex->y, ex->width, ex->height);
-        }
-    } while (!QUIT(e,k));
+    if (rpng2_info.state >= kWindowInit) {
+        Trace((stderr, "entering final wait-for-quit-event loop\n"))
+        do {
+            XNextEvent(display, &e);
+            if (e.type == Expose) {
+                XExposeEvent *ex = (XExposeEvent *)&e;
+                rpng2_x_redisplay_image (ex->x, ex->y, ex->width, ex->height);
+            }
+        } while (!QUIT(e,k));
+    } else {
+        fprintf(stderr, PROGNAME ":  init callback never called:  probable "
+          "libpng error while decoding PNG metadata\n");
+        exit(4);
+    }


    /* we're done:  clean up all image and X resources and go away */
@@ -719,6 +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;
 }

@@ -736,7 +777,7 @@ static void rpng2_x_init(void)
    ulg rowbytes = rpng2_info.rowbytes;

    Trace((stderr, "beginning rpng2_x_init()\n"))
-    Trace((stderr, "  rowbytes = %ld\n", rpng2_info.rowbytes))
+    Trace((stderr, "  rowbytes = %d\n", rpng2_info.rowbytes))
    Trace((stderr, "  width  = %ld\n", rpng2_info.width))
    Trace((stderr, "  height = %ld\n", rpng2_info.height))

@@ -765,14 +806,17 @@ static void rpng2_x_init(void)
    if (rpng2_x_create_window()) {

        /* GRR TEMPORARY HACK:  this is fundamentally no different from cases
-         * above; libpng should longjmp() back to us when png_ptr goes away.
-         * If we/it segfault instead, seems like a libpng bug... */
+         * above; libpng should call our error handler to longjmp() back to us
+         * when png_ptr goes away.  If we/it segfault instead, seems like a
+         * libpng bug... */

        /* we're here via libpng callback, so if window fails, clean and bail */
        readpng2_cleanup(&rpng2_info);
        rpng2_x_cleanup();
        exit(2);
    }
+
+    rpng2_info.state = kWindowInit;
 }


@@ -1258,7 +1302,7 @@ static int rpng2_x_load_bg_image(void)
        for (row = 0;  row < rpng2_info.height;  ++row) {
            src = bg_data + row*bg_rowbytes;
            dest = ximage->data + row*ximage_rowbytes;
-            if (bpp == 32) {	/* slightly optimized version */
+            if (bpp == 32) {    /* slightly optimized version */
                for (i = rpng2_info.width;  i > 0;  --i) {
                    red   = *src++;
                    green = *src++;
@@ -1556,7 +1600,7 @@ static void rpng2_x_finish_display(void)
     * have nothing to do here except set a flag and let the user know that
     * the image is done */

-    rpng2_info.done = TRUE;
+    rpng2_info.state = kDone;
    printf(
      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
    fflush(stdout);
@@ -1581,9 +1625,9 @@ static void rpng2_x_redisplay_image(ulg startcol, ulg startrow,


    Trace((stderr, "beginning display loop (image_channels == %d)\n",
-      image_channels))
-    Trace((stderr, "   (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
-      rpng2_info.width, image_rowbytes, ximage_rowbytes))
+      rpng2_info.channels))
+    Trace((stderr, "   (width = %ld, rowbytes = %d, ximage_rowbytes = %d)\n",
+      rpng2_info.width, rpng2_info.rowbytes, ximage_rowbytes))
    Trace((stderr, "   (bpp = %d)\n", ximage->bits_per_pixel))
    Trace((stderr, "   (byte_order = %s)\n", ximage->byte_order == MSBFirst?
      "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
@@ -1807,6 +1851,9 @@ static void rpng2_x_redisplay_image(ulg startcol, ulg startrow,
        XFlush(display);
    }

+    (void)startcol;
+    (void)width;
+
 } /* end function rpng2_x_redisplay_image() */


--- a/contrib/gregbook/writepng.c
+++ b/contrib/gregbook/writepng.c
@@ -55,8 +55,9 @@


 #include <stdlib.h>     /* for exit() prototype */
+#include <zlib.h>

-#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include "png.h"        /* libpng header, includes setjmp.h */
 #include "writepng.h"   /* typedefs, common macros, public prototypes */


@@ -89,7 +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 */
@@ -104,7 +105,8 @@ int writepng_init(mainprog_info *mainprog_ptr)
    /* setjmp() must be called in every function that calls a PNG-writing
     * libpng function, unless an alternate error handler was installed--
     * but compatible error handlers must either use longjmp() themselves
-     * (as in this program) or exit immediately, so here we go: */
+     * (as in this program) or some other method to return control to
+     * application code, so here we go: */

    if (setjmp(mainprog_ptr->jmpbuf)) {
        png_destroy_write_struct(&png_ptr, &info_ptr);
@@ -388,5 +390,12 @@ static void writepng_error_handler(png_structp png_ptr, png_const_charp msg)
        exit(99);
    }

+    /* Now we have our data structure we can use the information in it
+     * to return control to our own higher level code (all the points
+     * where 'setjmp' is called in this file.)  This will work with other
+     * error handling mechanisms as well - libpng always calls png_error
+     * when it can proceed no further, thus, so long as the error handler
+     * is intercepted, application code can do its own error recovery.
+     */
    longjmp(mainprog_ptr->jmpbuf, 1);
 }
--- a/contrib/libtests/fakepng.c
+++ b/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);
+}
--- a/contrib/libtests/gentests.sh
+++ b/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
--- a/contrib/libtests/makepng.c
+++ b/contrib/libtests/makepng.c
--- a/contrib/libtests/pngimage.c
+++ b/contrib/libtests/pngimage.c
--- a/contrib/libtests/pngstest.c
+++ b/contrib/libtests/pngstest.c
--- a/contrib/libtests/pngunknown.c
+++ b/contrib/libtests/pngunknown.c
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
--- a/contrib/libtests/readpng.c
+++ b/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);
+}
--- a/contrib/libtests/tarith.c
+++ b/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;
+}
--- a/contrib/libtests/timepng.c
+++ b/contrib/libtests/timepng.c
@@ -0,0 +1,303 @@
+/* timepng.c
+ *
+ * Copyright (c) 2013 John Cunningham Bowler
+ *
+ * Last changed in libpng 1.6.1 [March 28, 2013]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
+ * Load an arbitrary number of PNG files (from the command line, or, if there
+ * are no arguments on the command line, from stdin) then run a time test by
+ * reading each file by row.  The test does nothing with the read result and
+ * does no transforms.  The only output is a time as a floating point number of
+ * seconds with 9 decimal digits.
+ */
+#define _POSIX_C_SOURCE 199309L /* for clock_gettime */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <time.h>
+
+#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
+#  include <config.h>
+#endif
+
+/* Define the following to use this test against your installed libpng, rather
+ * than the one being built here:
+ */
+#ifdef PNG_FREESTANDING_TESTS
+#  include <png.h>
+#else
+#  include "../../png.h"
+#endif
+
+static int read_png(FILE *fp)
+{
+   png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+   png_infop info_ptr = NULL;
+   png_bytep row = NULL, display = NULL;
+
+   if (png_ptr == NULL)
+      return 0;
+
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+      if (row != NULL) free(row);
+      if (display != NULL) free(display);
+      return 0;
+   }
+
+   png_init_io(png_ptr, fp);
+
+   info_ptr = png_create_info_struct(png_ptr);
+   if (info_ptr == NULL)
+      png_error(png_ptr, "OOM allocating info structure");
+
+   png_read_info(png_ptr, info_ptr);
+
+   {
+      png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+
+      row = malloc(rowbytes);
+      display = malloc(rowbytes);
+
+      if (row == NULL || display == NULL)
+         png_error(png_ptr, "OOM allocating row buffers");
+
+      {
+         png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
+         int passes = png_set_interlace_handling(png_ptr);
+         int pass;
+
+         png_start_read_image(png_ptr);
+
+         for (pass = 0; pass < passes; ++pass)
+         {
+            png_uint_32 y = height;
+
+            /* NOTE: this trashes the row each time; interlace handling won't
+             * work, but this avoids memory thrashing for speed testing.
+             */
+            while (y-- > 0)
+               png_read_row(png_ptr, row, display);
+         }
+      }
+   }
+
+   /* Make sure to read to the end of the file: */
+   png_read_end(png_ptr, info_ptr);
+   png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+   free(row);
+   free(display);
+   return 1;
+}
+
+static int mytime(struct timespec *t)
+{
+   /* Do the timing using clock_gettime and the per-process timer. */
+   if (!clock_gettime(CLOCK_PROCESS_CPUTIME_ID, t))
+      return 1;
+
+   perror("CLOCK_PROCESS_CPUTIME_ID");
+   fprintf(stderr, "timepng: could not get the time\n");
+   return 0;
+}
+
+static int perform_one_test(FILE *fp, int nfiles)
+{
+   int i;
+   struct timespec before, after;
+
+   /* Clear out all errors: */
+   rewind(fp);
+
+   if (mytime(&before))
+   {
+      for (i=0; i<nfiles; ++i)
+      {
+         if (read_png(fp))
+         {
+            if (ferror(fp))
+            {
+               perror("temporary file");
+               fprintf(stderr, "file %d: error reading PNG data\n", i);
+               return 0;
+            }
+         }
+
+         else
+         {
+            perror("temporary file");
+            fprintf(stderr, "file %d: error from libpng\n", i);
+            return 0;
+         }
+      }
+   }
+
+   else
+      return 0;
+
+   if (mytime(&after))
+   {
+      /* Work out the time difference and print it - this is the only output,
+       * so flush it immediately.
+       */
+      unsigned long s = after.tv_sec - before.tv_sec;
+      long ns = after.tv_nsec - before.tv_nsec;
+
+      if (ns < 0)
+      {
+         --s;
+         ns += 1000000000;
+
+         if (ns < 0)
+         {
+            fprintf(stderr, "timepng: bad clock from kernel\n");
+            return 0;
+         }
+      }
+
+      printf("%lu.%.9ld\n", s, ns);
+      fflush(stdout);
+      if (ferror(stdout))
+      {
+         fprintf(stderr, "timepng: error writing output\n");
+         return 0;
+      }
+
+      /* Successful return */
+      return 1;
+   }
+
+   else
+      return 0;
+}
+
+static int add_one_file(FILE *fp, char *name)
+{
+   FILE *ip = fopen(name, "rb");
+
+   if (ip != NULL)
+   {
+      int ch;
+      for (;;)
+      {
+         ch = getc(ip);
+         if (ch == EOF) break;
+         putc(ch, fp);
+      }
+
+      if (ferror(ip))
+      {
+         perror(name);
+         fprintf(stderr, "%s: read error\n", name);
+         return 0;
+      }
+
+      (void)fclose(ip);
+
+      if (ferror(fp))
+      {
+         perror("temporary file");
+         fprintf(stderr, "temporary file write error\n");
+         return 0;
+      }
+   }
+
+   else
+   {
+      perror(name);
+      fprintf(stderr, "%s: open failed\n", name);
+      return 0;
+   }
+
+   return 1;
+}
+
+int main(int argc, char **argv)
+{
+   int ok = 0;
+   FILE *fp = tmpfile();
+
+   if (fp != NULL)
+   {
+      int err = 0;
+      int nfiles = 0;
+
+      if (argc > 1)
+      {
+         int i;
+
+         for (i=1; i<argc; ++i)
+         {
+            if (add_one_file(fp, argv[i]))
+               ++nfiles;
+
+            else
+            {
+               err = 1;
+               break;
+            }
+         }
+      }
+
+      else
+      {
+         char filename[FILENAME_MAX+1];
+
+         while (fgets(filename, FILENAME_MAX+1, stdin))
+         {
+            size_t len = strlen(filename);
+
+            if (filename[len-1] == '\n')
+            {
+               filename[len-1] = 0;
+               if (add_one_file(fp, filename))
+                  ++nfiles;
+
+               else
+               {
+                  err = 1;
+                  break;
+               }
+            }
+
+            else
+            {
+               fprintf(stderr, "timepng: truncated file name ...%s\n",
+                  filename+len-32);
+               err = 1;
+               break;
+            }
+         }
+
+         if (ferror(stdin))
+         {
+            fprintf(stderr, "timepng: stdin: read error\n");
+            err = 1;
+         }
+      }
+
+      if (!err)
+      {
+         if (nfiles > 0)
+            ok = perform_one_test(fp, nfiles);
+
+         else
+            fprintf(stderr, "usage: timepng {files} or ls files | timepng\n");
+      }
+
+      (void)fclose(fp);
+   }
+
+   else
+      fprintf(stderr, "timepng: could not open temporary file\n");
+
+   /* Exit code 0 on success. */
+   return ok == 0;
+}
--- a/contrib/pngminim/README
+++ b/contrib/pngminim/README
@@ -0,0 +1,5 @@
+
+This demonstrates the use of PNG_USER_CONFIG, pngusr.h and pngusr.dfa
+to build minimal decoder, encoder, and progressive reader applications.
+
+See the individual README and pngusr.dfa files for more explanation.
--- a/contrib/pngminim/decoder/README
+++ b/contrib/pngminim/decoder/README
@@ -1,6 +1,10 @@
-This demonstrates the use of PNG_USER_CONFIG and pngusr.h
+This demonstrates the use of PNG_USER_CONFIG, pngusr.h and pngusr.dfa

-To build a minimal read-only decoder, run
-    gather.sh  # to collect needed files from pngminus, libpng, and zlib
-    make -f makefile.std
- 
+The makefile builds a minimal read-only decoder with embedded libpng
+and zlib.
+
+Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
+on the make command line.
+
+If you prefer to use the shared libraries, go to contrib/pngminus
+and build the png2pnm application there.
--- a/contrib/pngminim/decoder/gather.sh
+++ b/contrib/pngminim/decoder/gather.sh
@@ -1,8 +0,0 @@
-cp ../../pngminus/png2pnm.c pngm2pnm.c
-cp ../../../*.h .
-cp ../../../*.c .
-rm example.c pnggccrd.c pngvcrd.c pngtest.c
-# change the following 2 lines if zlib is somewhere else
-cp ../../../../zlib/*.h .
-cp ../../../../zlib/*.c .
-rm minigzip.c example.c compress.c deflate.c
--- a/contrib/pngminim/decoder/makefile
+++ b/contrib/pngminim/decoder/makefile
@@ -0,0 +1,151 @@
+# Makefile for PngMinus (pngm2pnm)
+# Linux / Unix
+
+#CC=cc
+CC=gcc
+LD=$(CC)
+
+# If awk fails try
+# make AWK=nawk
+
+# If cpp fails try
+# make CPP=/lib/cpp
+
+RM=rm -f
+COPY=cp
+
+CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
+
+C=.c
+O=.o
+L=.a
+E=
+
+# Where to find the source code:
+PNGSRC =../../..
+ZLIBSRC=$(PNGSRC)/../zlib
+PROGSRC=$(PNGSRC)/contrib/pngminus
+
+# Zlib (minimal inflate requirements - crc32 is used by libpng)
+# zutil can be eliminated if you provide your own zcalloc and zcfree
+ZSRCS  = adler32$(C) crc32$(C) \
+	 inffast$(C) inflate$(C) inftrees$(C) \
+	 zutil$(C)
+
+# Standard headers
+ZH     = zlib.h crc32.h inffast.h inffixed.h \
+	 inflate.h inftrees.h zutil.h
+
+# Machine generated headers
+ZCONF  = zconf.h
+
+# Headers callers use
+ZINC   = zlib.h $(ZCONF)
+
+# Headers the Zlib source uses
+ZHDRS  = $(ZH) $(ZCONF)
+
+ZOBJS  = adler32$(O) crc32$(O) \
+	 inffast$(O) inflate$(O) inftrees$(O) \
+	 zutil$(O)
+
+# libpng
+PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
+	pngread$(C) pngrio$(C) pngrtran$(C) pngrutil$(C) \
+	pngset$(C) pngtrans$(C)
+	
+# Standard headers
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+
+# Machine generated headers
+PNGCONF=pnglibconf.h
+
+# Headers callers use
+PNGINC= png.h pngconf.h pngusr.h $(PNGCONF)
+
+# Headers the PNG library uses
+PNGHDRS=$(PNGH) $(PNGCONF) pngusr.h
+
+PNGOBJS=png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
+	pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) \
+	pngset$(O) pngtrans$(O)
+
+PROGSRCS= pngm2pnm$(C)
+PROGHDRS=
+PROGDOCS=
+PROGOBJS= pngm2pnm$(O)
+
+OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
+
+# implicit make rules -------------------------------------------------------
+
+# note: dependencies do not work on implicit rule lines
+.c$(O):
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
+
+# dependencies
+
+all: pngm2pnm$(E)
+
+pngm2pnm$(E): $(OBJS)
+	$(LD) -o pngm2pnm$(E) $(OBJS)
+
+# The DFA_XTRA setting turns all libpng options off then
+# turns on those required for this minimal build.
+# The CPP_FLAGS setting causes pngusr.h to be included in
+# both the build of pnglibconf.h and, subsequently, when
+# building libpng itself.
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
+	$(PNGSRC)/scripts/pnglibconf.dfa \
+	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
+	$(RM) pnglibconf.h pnglibconf.dfn
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
+	    DFA_XTRA="pngusr.dfa" $@
+
+clean:
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) clean
+	$(RM) pngm2pnm$(O)
+	$(RM) pngm2pnm$(E)
+	$(RM) $(OBJS)
+
+# distclean also removes the copied source and headers
+distclean: clean
+	$(RM) -r scripts # historical reasons
+	$(RM) $(PNGSRCS) $(PNGH)
+	$(RM) $(ZSRCS) $(ZH) $(ZCONF)
+	$(RM) $(PROGSRCS) $(PROGHDRS) $(PROGDOCS)
+
+# Header file dependencies:
+$(PROGOBJS): $(PROGHDRS) $(PNGINC) $(ZINC)
+$(PNGOBJS): $(PNGHDRS) $(ZINC)
+$(ZOBJS): $(ZHDRS)
+
+# Gather the source code from the respective directories
+$(PNGSRCS) $(PNGH): $(PNGSRC)/$@
+	$(RM) $@
+	$(COPY) $(PNGSRC)/$@ $@
+
+# No dependency on the ZLIBSRC target so that it only needs
+# to be specified once.
+$(ZSRCS) $(ZH):
+	$(RM) $@
+	$(COPY) $(ZLIBSRC)/$@ $@
+
+# The unconfigured zconf.h varies in name according to the
+# zlib release
+$(ZCONF):
+	$(RM) $@
+	@for f in zconf.h.in zconf.in.h zconf.h; do\
+	    test -r $(ZLIBSRC)/$$f &&\
+	    echo $(COPY) $(ZLIBSRC)/$$f $@ &&\
+	    $(COPY) $(ZLIBSRC)/$$f $@ && exit 0;\
+	done; echo copy: $(ZLIBSRC)/zconf.h not found; exit 1
+
+pngm2pnm.c: $(PROGSRC)/png2pnm.c
+	$(RM) $@
+	$(COPY) $(PROGSRC)/png2pnm.c $@
+
+# End of makefile for pngm2pnm
--- a/contrib/pngminim/decoder/makefile.std
+++ b/contrib/pngminim/decoder/makefile.std
@@ -1,44 +0,0 @@
-# Makefile for PngMinus (pngm2pnm)
-# Linux / Unix
-
-#CC=cc
-CC=gcc
-LD=$(CC)
-
-RM=rm -f
-
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZCOMPRESS -DNO_GZIP \
-       -DdeflateParams\(a,b,c\)=Z_OK -I. -O1
-
-C=.c
-O=.o
-L=.a
-E=
-
-ZOBJS  = adler32$(O) crc32$(O) gzio$(O) \
-	 infback$(O) inffast$(O) inflate$(O) inftrees$(O) \
-	 trees$(O) uncompr$(O) zutil$(O)
-
-OBJS  = pngm2pnm$(O) png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
-	pngpread$(O) pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) \
-	pngset$(O) pngtrans$(O)  $(ZOBJS)
-
-# implicit make rules -------------------------------------------------------
-
-.c$(O): png.h pngconf.h pngusr.h zlib.h
-	$(CC) -c $(CFLAGS) $<
-
-# dependencies
-
-all: pngm2pnm$(E)
-
-pngm2pnm$(E): $(OBJS)
-	$(LD) -o pngm2pnm$(E) $(OBJS)
-	strip pngm2pnm$(E)
-
-clean:
-	$(RM) pngm2pnm$(O)
-	$(RM) pngm2pnm$(E)
-	$(RM) $(OBJS)
-
-# End of makefile for pngm2pnm
--- a/contrib/pngminim/decoder/pngusr.dfa
+++ b/contrib/pngminim/decoder/pngusr.dfa
@@ -0,0 +1,40 @@
+# pngminim/decoder/pngusr.dfa
+#
+# Copyright (c) 2010-2013 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# First all the build options off:
+
+everything = off
+
+# All that is required is some read code. This example switches
+# on the sequential read code (see ../preader for a progressive
+# read example).
+
+option SEQUENTIAL_READ on
+
+# You must choose fixed or floating point arithmetic:
+# option FLOATING_POINT on
+
+option FIXED_POINT on
+
+# You must chose the internal fixed point implementation or to
+# use the system floating point.  The latter is considerably
+# smaller (by about 1kbyte on an x86 system):
+# option FLOATING_ARITHMETIC on
+
+option FLOATING_ARITHMETIC off
+
+# Your program will probably need other options.  The example
+# program here, pngm2pnm, requires the following.  Take a look
+# at pnglibconf.h to find out the full set of what has to be
+# enabled to make the following work.
+
+option SETJMP on
+option STDIO on
+option READ_EXPAND on
+option READ_STRIP_16_TO_8 on
+option USER_LIMITS on
--- a/contrib/pngminim/decoder/pngusr.h
+++ b/contrib/pngminim/decoder/pngusr.h
@@ -1,64 +1,23 @@
 /* minrdpngconf.h: headers to make a minimal png-read-only library
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 2007 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
+ * and license in png.h
+ *
 * Derived from pngcrush.h, Copyright 1998-2007, Glenn Randers-Pehrson
 */

 #ifndef MINRDPNGCONF_H
 #define MINRDPNGCONF_H

-#define PNG_NO_GLOBAL_ARRAYS
+/* To include pngusr.h set -DPNG_USER_CONFIG in CPPFLAGS */

-#define PNG_NO_WARNINGS
-#define png_warning(s1,s2) ""
-#define png_chunk_warning(s1,s2) ""
+/* List options to turn off features of the build that do not
+ * affect the API (so are not recorded in pnglibconf.h)
+ */

-#define PNG_NO_ASSEMBLER_CODE
-#define PNG_NO_OPTIMIZED_CODE
-#define PNG_NO_READ_GAMMA
-#define PNG_NO_READ_BACKGROUND
-#define PNG_NO_READ_DITHER
-#define PNG_NO_READ_INVERT
-#define PNG_NO_READ_SHIFT
-#define PNG_NO_READ_PACK
-#define PNG_NO_READ_PACKSWAP
-#define PNG_NO_READ_FILLER
-#define PNG_NO_READ_SWAP_ALPHA
-#define PNG_NO_READ_INVERT_ALPHA
-#define PNG_NO_READ_RGB_TO_GRAY
-#define PNG_NO_READ_USER_TRANSFORM
-#define PNG_NO_READ_bKGD
-#define PNG_NO_READ_cHRM
-#define PNG_NO_READ_gAMA
-#define PNG_NO_READ_hIST
-#define PNG_NO_READ_iCCP
-#define PNG_NO_READ_pCAL
-#define PNG_NO_READ_pHYs
-#define PNG_NO_READ_sBIT
-#define PNG_NO_READ_sCAL
-#define PNG_NO_READ_sPLT
-#define PNG_NO_READ_TEXT
-#define PNG_NO_READ_tIME
-#define PNG_NO_READ_UNKNOWN_CHUNKS
-#define PNG_NO_READ_USER_CHUNKS
-#define PNG_NO_READ_EMPTY_PLTE
-#define PNG_NO_READ_OPT_PLTE
-#define PNG_NO_READ_STRIP_ALPHA
-#define PNG_NO_READ_oFFs
-#define PNG_NO_WARN_UNINITIALIZED_ROW
-
-#define PNG_NO_WRITE_SUPPORTED
-
-#define PNG_NO_INFO_IMAGE
-#define PNG_NO_USER_MEM
-#define PNG_NO_FIXED_POINT_SUPPORTED
-#define PNG_NO_MNG_FEATURES
-#define PNG_NO_USER_TRANSFORM_PTR
-#define PNG_NO_HANDLE_AS_UNKNOWN
-#define PNG_NO_CONSOLE_IO
-#define PNG_NO_ZALLOC_ZERO
-#define PNG_NO_ERROR_NUMBERS
-#define PNG_NO_EASY_ACCESS
-#define PNG_NO_PROGRESSIVE_READ
+#define PNG_ALIGN_TYPE PNG_ALIGN_NONE

 #endif /* MINRDPNGCONF_H */
--- a/contrib/pngminim/encoder/README
+++ b/contrib/pngminim/encoder/README
@@ -1,6 +1,10 @@
 This demonstrates the use of PNG_USER_CONFIG and pngusr.h

-To build a minimal write-only encoder, run
-    gather.sh  # to collect needed files from pngminus, libpng, and zlib
-    make -f makefile.std
- 
+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
+on the make command line.
+
+If you prefer to use the shared libraries, go to contrib/pngminus
+and build the pnm2png application there.
--- a/contrib/pngminim/encoder/dummy_inflate.c
+++ b/contrib/pngminim/encoder/dummy_inflate.c
@@ -1,27 +0,0 @@
-#include "zlib.h"
-
-int ZEXPORT inflate(strm, flush)
-z_streamp strm;
-int flush;
-{ return Z_OK ; }
-
-int ZEXPORT inflateReset(strm)
-z_streamp strm;
-{ return Z_OK ; }
-
-int ZEXPORT inflateEnd(strm)
-z_streamp strm;
-{ return Z_STREAM_ERROR ; }
-
-int ZEXPORT inflateInit_(strm, version, stream_size)
-z_streamp strm;
-const char *version;
-int stream_size;
-{ return Z_OK ; }
-
-int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
-z_streamp strm;
-int windowBits;
-const char *version;
-int stream_size;
-{ return Z_STREAM_ERROR ; }
--- a/contrib/pngminim/encoder/gather.sh
+++ b/contrib/pngminim/encoder/gather.sh
@@ -1,9 +0,0 @@
-cp ../../pngminus/pnm2png.c pnm2pngm.c
-cp ../../../*.h .
-cp ../../../*.c .
-rm example.c pnggccrd.c pngvcrd.c pngtest.c
-# Change the next 2 lines if zlib is somewhere else.
-cp ../../../../zlib/*.h .
-cp ../../../../zlib/*.c .
-rm inf*.[ch]
-rm minigzip.c example.c
--- a/contrib/pngminim/encoder/makefile
+++ b/contrib/pngminim/encoder/makefile
@@ -0,0 +1,150 @@
+# Makefile for PngMinus (pnm2pngm)
+# Linux / Unix
+
+#CC=cc
+CC=gcc
+LD=$(CC)
+
+# If awk fails try
+# make AWK=nawk
+
+# If cpp fails try
+# make CPP=/lib/cpp
+
+RM=rm -f
+COPY=cp
+
+CPPFLAGS=-I. -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
+
+C=.c
+O=.o
+L=.a
+E=
+
+# Where to find the source code:
+PNGSRC =../../..
+ZLIBSRC=$(PNGSRC)/../zlib
+PROGSRC=$(PNGSRC)/contrib/pngminus
+
+# Zlib
+ZSRCS  = adler32$(C) compress$(C) crc32$(C) deflate$(C) \
+	 trees$(C) zutil$(C)
+
+# Standard headers
+#ZH     = zlib.h crc32.h deflate.h trees.h zutil.h
+ZH     = zlib.h crc32.h deflate.h trees.h zutil.h
+
+# Machine generated headers
+ZCONF  = zconf.h
+
+# Headers callers use
+ZINC   = zlib.h $(ZCONF)
+
+# Headers the Zlib source uses
+ZHDRS  = $(ZH) $(ZCONF)
+
+# compress is not required; it is needed to link the zlib
+# code because deflate defines an unused API function deflateBound
+# which itself calls compressBound from compress.
+ZOBJS  = adler32$(O) compress$(O) crc32$(O) deflate$(O) \
+	 trees$(O) zutil$(O)
+
+# libpng
+PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
+	pngset$(C) pngtrans$(C) pngwio$(C) pngwrite$(C) \
+	pngwtran$(C) pngwutil$(C)
+
+# Standard headers
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+
+# Machine generated headers
+PNGCONF=pnglibconf.h
+
+# Headers callers use
+PNGINC= png.h pngconf.h pngusr.h $(PNGCONF)
+
+# Headers the PNG library uses
+PNGHDRS=$(PNGH) $(PNGCONF) pngusr.h
+
+PNGOBJS=png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
+	pngset$(O) pngtrans$(O) pngwio$(O) pngwrite$(O) \
+	pngwtran$(O) pngwutil$(O)
+
+PROGSRCS= pnm2pngm$(C)
+PROGHDRS=
+PROGDOCS=
+PROGOBJS= pnm2pngm$(O)
+
+OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
+
+# dependencies
+
+all: pnm2pngm$(E)
+
+pnm2pngm$(E): $(OBJS)
+	$(LD) -o pnm2pngm$(E) $(OBJS)
+
+# The DFA_XTRA setting turns all libpng options off then
+# turns on those required for this minimal build.
+# The CPP_FLAGS setting causes pngusr.h to be included in
+# both the build of pnglibconf.h and, subsequently, when
+# building libpng itself.
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
+	$(PNGSRC)/scripts/pnglibconf.dfa \
+	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
+	$(RM) pnglibconf.h pnglibconf.dfn
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
+	    DFA_XTRA="pngusr.dfa" $@
+
+clean:
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) clean
+	$(RM) pnm2pngm$(O)
+	$(RM) pnm2pngm$(E)
+	$(RM) $(OBJS)
+
+# distclean also removes the copied source and headers
+distclean: clean
+	$(RM) -r scripts # historical reasons
+	$(RM) $(PNGSRCS) $(PNGH)
+	$(RM) $(ZSRCS) $(ZH) $(ZCONF)
+	$(RM) $(PROGSRCS) $(PROGHDRS) $(PROGDOCS)
+
+# Header file dependencies:
+$(PROGOBJS): $(PROGHDRS) $(PNGINC) $(ZINC)
+$(PNGOBJS): $(PNGHDRS) $(ZINC)
+$(ZOBJS): $(ZHDRS)
+
+# Gather the source code from the respective directories
+$(PNGSRCS) $(PNGH): $(PNGSRC)/$@
+	$(RM) $@
+	$(COPY) $(PNGSRC)/$@ $@
+
+# No dependency on the ZLIBSRC target so that it only needs
+# to be specified once.
+$(ZSRCS) $(ZH):
+	$(RM) $@
+	$(COPY) $(ZLIBSRC)/$@ $@
+
+# The unconfigured zconf.h varies in name according to the
+# zlib release
+$(ZCONF):
+	$(RM) $@
+	@for f in zconf.h.in zconf.in.h zconf.h; do\
+	    test -r $(ZLIBSRC)/$$f &&\
+	    echo $(COPY) $(ZLIBSRC)/$$f $@ &&\
+	    $(COPY) $(ZLIBSRC)/$$f $@ && exit 0;\
+	done; echo copy: $(ZLIBSRC)/zconf.h not found; exit 1
+
+pnm2pngm.c: $(PROGSRC)/pnm2png.c
+	$(RM) $@
+	$(COPY) $(PROGSRC)/pnm2png.c $@
+
+# End of makefile for pnm2pngm
--- a/contrib/pngminim/encoder/makefile.std
+++ b/contrib/pngminim/encoder/makefile.std
@@ -1,44 +0,0 @@
-# Makefile for PngMinus (pnm2pngm)
-# Linux / Unix
-
-#CC=cc
-CC=gcc
-LD=$(CC)
-
-RM=rm -f
-
-CFLAGS=-DPNG_USER_CONFIG -DNO_GZIP -I. -O1
-
-C=.c
-O=.o
-L=.a
-E=
-
-ZOBJS  = adler32$(O) compress$(O) crc32$(O) deflate$(O) gzio$(O) \
-	 dummy_inflate$(O) \
-	 trees$(O) uncompr$(O) zutil$(O)
-
-OBJS  = pnm2pngm$(O) png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
-	pngpread$(O) pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) \
-	pngset$(O) pngtrans$(O) pngwio$(O) pngwrite$(O) \
-	pngwtran$(O) pngwutil$(O) $(ZOBJS)
-
-# implicit make rules -------------------------------------------------------
-
-.c$(O): png.h pngconf.h pngusr.h zlib.h
-	$(CC) -c $(CFLAGS) $<
-
-# dependencies
-
-all: pnm2pngm$(E)
-
-pnm2pngm$(E): $(OBJS)
-	$(LD) -o pnm2pngm$(E) $(OBJS)
-	strip pnm2pngm$(E)
-
-clean:
-	$(RM) pnm2pngm$(O)
-	$(RM) pnm2pngm$(E)
-	$(RM) $(OBJS)
-
-# End of makefile for pnm2pngm
--- a/contrib/pngminim/encoder/pngusr.dfa
+++ b/contrib/pngminim/encoder/pngusr.dfa
@@ -0,0 +1,39 @@
+# pngminim/encoder/pngusr.dfa
+#
+# Copyright (c) 2010-2013 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# First all the build options off:
+
+everything = off
+
+# Switch on the write code - this makes a minimalist encoder
+
+option WRITE on
+
+# These 2 options are required if you need to read 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
+
+option FIXED_POINT on
+
+# You must chose the internal fixed point implementation or to
+# use the system floating point.  The latter is considerably
+# smaller (by about 1kbyte on an x86 system):
+# option FLOATING_ARITHMETIC on
+
+option FLOATING_ARITHMETIC off
+
+# Your program will probably need other options.  The example
+# program here, pnm2pngm, requires the following.  Take a look
+# at pnglibconf.h to find out the full set of what has to be
+# enabled to make the following work.
+
+option SETJMP on
+option STDIO on
--- a/contrib/pngminim/encoder/pngusr.h
+++ b/contrib/pngminim/encoder/pngusr.h
@@ -1,63 +1,23 @@
 /* minwrpngconf.h: headers to make a minimal png-write-only library
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 2007 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
+ * and license in png.h
+ *
 * Derived from pngcrush.h, Copyright 1998-2007, Glenn Randers-Pehrson
 */

 #ifndef MINWRPNGCONF_H
 #define MINWRPNGCONF_H

-#define PNG_NO_GLOBAL_ARRAYS
+/* To include pngusr.h set -DPNG_USER_CONFIG in CPPFLAGS */

-#define PNG_NO_READ_SUPPORTED
+/* List options to turn off features of the build that do not
+ * affect the API (so are not recorded in pnglibconf.h)
+ */

-#define PNG_NO_WARNINGS
-#define png_warning(s1,s2) ""
-#define png_chunk_warning(s1,s2) ""
-
-#define PNG_NO_WRITE_BACKGROUND
-#define PNG_NO_WRITE_GAMMA
-#define PNG_NO_WRITE_DITHER
-#define PNG_NO_WRITE_INVERT
-#define PNG_NO_WRITE_SHIFT
-#define PNG_NO_WRITE_PACK
-#define PNG_NO_WRITE_PACKSWAP
-#define PNG_NO_WRITE_FILLER
-#define PNG_NO_WRITE_SWAP_ALPHA
-#define PNG_NO_WRITE_INVERT_ALPHA
-#define PNG_NO_WRITE_RGB_TO_GRAY
-#define PNG_NO_WRITE_USER_TRANSFORM
-#define PNG_NO_WRITE_bKGD
-#define PNG_NO_WRITE_cHRM
-#define PNG_NO_WRITE_gAMA
-#define PNG_NO_WRITE_sRGB
-#define PNG_NO_WRITE_hIST
-#define PNG_NO_WRITE_iCCP
-#define PNG_NO_WRITE_oFFs
-#define PNG_NO_WRITE_pCAL
-#define PNG_NO_WRITE_pHYs
-#define PNG_NO_WRITE_sBIT
-#define PNG_NO_WRITE_sCAL
-#define PNG_NO_WRITE_sPLT
-#define PNG_NO_WRITE_TEXT
-#define PNG_NO_WRITE_tIME
-#define PNG_NO_WRITE_UNKNOWN_CHUNKS
-#define PNG_NO_WRITE_USER_CHUNKS
-#define PNG_NO_WRITE_EMPTY_PLTE
-#define PNG_NO_WRITE_OPT_PLTE
-#define PNG_NO_WRITE_FILTER
-#define PNG_NO_WRITE_WEIGHTED_FILTER
-#define PNG_NO_WRITE_INTERLACING_SUPPORTED  /* effective libpng-1.3.0 */
-
-#define PNG_NO_INFO_IMAGE
-#define PNG_NO_USER_MEM
-#define PNG_NO_FIXED_POINT_SUPPORTED
-#define PNG_NO_MNG_FEATURES
-#define PNG_NO_USER_TRANSFORM_PTR
-#define PNG_NO_HANDLE_AS_UNKNOWN
-#define PNG_NO_CONSOLE_IO
-#define PNG_NO_ZALLOC_ZERO
-#define PNG_NO_ERROR_NUMBERS
-#define PNG_NO_EASY_ACCESS
+#define PNG_ALIGN_TYPE PNG_ALIGN_NONE

 #endif /* MINWRPNGCONF_H */
--- a/contrib/pngminim/preader/README
+++ b/contrib/pngminim/preader/README
@@ -0,0 +1,15 @@
+This demonstrates the use of PNG_USER_CONFIG and pngusr.h
+
+The makefile builds a minimal read-only progressive decoder with
+embedded libpng, zlib and your system's X library.
+
+Specify the location of the zlib source (1.2.1 or later) as ZLIBSRC
+on the make command line.
+
+Edit makefile if required, to find your X library and include files,
+then
+
+    make ZLIBSRC=directory
+
+If you prefer to use the shared libraries, go to contrib/gregbook
+and build the rpng2-x application there.
--- a/contrib/pngminim/preader/makefile
+++ b/contrib/pngminim/preader/makefile
@@ -0,0 +1,166 @@
+# Makefile for PngMinus (rpng2)
+# Linux / Unix
+
+#CC=cc
+CC=gcc
+LD=$(CC)
+
+# If awk fails try
+# make AWK=nawk
+
+# If cpp fails try
+# make CPP=/lib/cpp
+
+RM=rm -f
+COPY=cp
+
+#XINC = -I/usr/include			# old-style, stock X distributions
+#XLIB = -L/usr/lib/X11 -lX11		#  (including SGI IRIX)
+
+#XINC = -I/usr/openwin/include		# Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+
+XINC = -I/usr/X11R6/include		# new X distributions (X.org, etc.)
+XLIB = -L/usr/X11R6/lib -lX11
+#XLIB = -L/usr/X11R6/lib64 -lX11	# e.g., Red Hat on AMD64
+
+#XINC = -I/usr/local/include   		# FreeBSD
+#XLIB = -L/usr/local/lib -lX11
+
+#LIBS = $(XLIB)
+LIBS = $(XLIB) -lm                      #platforms that need libm
+
+CPPFLAGS=-I. $(XINC) -DPNG_USER_CONFIG -DNO_GZCOMPRESS -DZ_SOLO -DNO_GZIP
+CFLAGS=-O1 -Wall
+
+C=.c
+O=.o
+L=.a
+E=
+
+# Where to find the source code:
+PNGSRC =../../..
+ZLIBSRC=$(PNGSRC)/../zlib
+PROGSRC=$(PNGSRC)/contrib/gregbook
+
+# Zlib (minimal inflate requirements - crc32 is used by libpng)
+# zutil can be eliminated if you provide your own zcalloc and zcfree
+ZSRCS  = adler32$(C) crc32$(C) \
+	 inffast$(C) inflate$(C) inftrees$(C) \
+	 zutil$(C)
+
+# Standard headers
+ZH     = zlib.h crc32.h inffast.h inffixed.h \
+	 inflate.h inftrees.h zutil.h
+
+# Machine generated headers
+ZCONF  = zconf.h
+
+# Headers callers use
+ZINC   = zlib.h $(ZCONF)
+
+# Headers the Zlib source uses
+ZHDRS  = $(ZH) $(ZCONF)
+
+ZOBJS  = adler32$(O) crc32$(O) \
+	 inffast$(O) inflate$(O) inftrees$(O) \
+	 zutil$(O)
+
+# libpng
+PNGSRCS=png$(C) pngerror$(C) pngget$(C) pngmem$(C) \
+	pngpread$(C) pngread$(C) pngrio$(C) pngrtran$(C) pngrutil$(C) \
+	pngset$(C) pngtrans$(C)
+
+# Standard headers
+PNGH   =png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h
+
+# Machine generated headers
+PNGCONF=pnglibconf.h
+
+# Headers callers use
+PNGINC= png.h pngconf.h pngusr.h $(PNGCONF)
+
+# Headers the PNG library uses
+PNGHDRS=$(PNGH) $(PNGCONF) pngusr.h
+
+PNGOBJS=png$(O) pngerror$(O) pngget$(O) pngmem$(O) \
+	pngpread$(O) pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) \
+	pngset$(O) pngtrans$(O)
+
+PROGSRCS= rpng2-x$(C) readpng2$(C)
+PROGHDRS= readpng2.h
+PROGDOCS= COPYING LICENSE
+PROGOBJS= rpng2-x$(O) readpng2$(O)
+
+OBJS    = $(PROGOBJS) $(PNGOBJS) $(ZOBJS)
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
+
+# dependencies
+
+all: $(PROGDOCS) rpng2-x$(E)
+
+rpng2-x$(E): $(OBJS)
+	$(LD) -o rpng2-x$(E) $(OBJS) $(LIBS)
+
+# The DFA_XTRA setting turns all libpng options off then
+# turns on those required for this minimal build.
+# The CPP_FLAGS setting causes pngusr.h to be included in
+# both the build of pnglibconf.h and, subsequently, when
+# building libpng itself.
+$(PNGCONF): $(PNGSRC)/scripts/pnglibconf.mak $(ZH)\
+	$(PNGSRC)/scripts/pnglibconf.dfa \
+	$(PNGSRC)/scripts/options.awk pngusr.h pngusr.dfa
+	$(RM) pnglibconf.h pnglibconf.dfn
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) CPPFLAGS="-DPNG_USER_CONFIG -I."\
+	    DFA_XTRA="pngusr.dfa" $@
+
+clean:
+	$(MAKE) -f $(PNGSRC)/scripts/pnglibconf.mak $(MAKEFLAGS)\
+	    srcdir=$(PNGSRC) clean
+	$(RM) rpng2-x$(O)
+	$(RM) rpng2-x$(E)
+	$(RM) $(OBJS)
+
+# distclean also removes the copied source and headers
+distclean: clean
+	$(RM) -r scripts # historical reasons
+	$(RM) $(PNGSRCS) $(PNGH)
+	$(RM) $(ZSRCS) $(ZH) $(ZCONF)
+	$(RM) $(PROGSRCS) $(PROGHDRS) $(PROGDOCS)
+
+# Header file dependencies:
+$(PROGOBJS): $(PROGHDRS) $(PNGINC) $(ZINC)
+$(PNGOBJS): $(PNGHDRS) $(ZINC)
+$(ZOBJS): $(ZHDRS)
+
+# Gather the source code from the respective directories
+$(PNGSRCS) $(PNGH): $(PNGSRC)/$@
+	$(RM) $@
+	$(COPY) $(PNGSRC)/$@ $@
+
+# No dependency on the ZLIBSRC target so that it only needs
+# to be specified once.
+$(ZSRCS) $(ZH):
+	$(RM) $@
+	$(COPY) $(ZLIBSRC)/$@ $@
+
+# The unconfigured zconf.h varies in name according to the
+# zlib release
+$(ZCONF):
+	$(RM) $@
+	@for f in zconf.h.in zconf.in.h zconf.h; do\
+	    test -r $(ZLIBSRC)/$$f &&\
+	    echo $(COPY) $(ZLIBSRC)/$$f $@ &&\
+	    $(COPY) $(ZLIBSRC)/$$f $@ && exit 0;\
+	done; echo copy: $(ZLIBSRC)/zconf.h not found; exit 1
+
+$(PROGSRCS) $(PROGHDRS) $(PROGDOCS): $(PROGSRC)/$@
+	$(RM) $@
+	$(COPY) $(PROGSRC)/$@ $@
+
+# End of makefile for rpng2-x
--- a/contrib/pngminim/preader/pngusr.dfa
+++ b/contrib/pngminim/preader/pngusr.dfa
@@ -0,0 +1,40 @@
+# pngminim/preader/pngusr.dfa
+#
+# Copyright (c) 2010-2013 Glenn Randers-Pehrson
+#
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+# First all the build options off:
+
+everything = off
+
+# Just switch on the progressive read code
+
+option PROGRESSIVE_READ on
+
+# You may choose fixed or floating point APIs:
+# option FLOATING_POINT on
+
+option FIXED_POINT on
+
+# You must chose the internal fixed point implementation or to
+# use the system floating point.  The latter is considerably
+# smaller (by about 1kbyte on an x86 system):
+
+option FLOATING_ARITHMETIC on
+# option FLOATING_ARITHMETIC off
+
+# Your program will probably need other options.  The example
+# program here, rpng2-x, requires the following.  Take a look
+# at pnglibconf.h to find out the full set of what has to be
+# enabled to make the following work.
+
+option SETJMP on
+option STDIO on
+option READ_bKGD on
+option READ_GAMMA on
+option READ_EXPAND on
+option READ_STRIP_16_TO_8 on
+option READ_GRAY_TO_RGB on
--- a/contrib/pngminim/preader/pngusr.h
+++ b/contrib/pngminim/preader/pngusr.h
@@ -0,0 +1,23 @@
+/* minrdpngconf.h: headers to make a minimal png-read-only library
+ *
+ * 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
+ * and license in png.h
+ *
+ * Derived from pngcrush.h, Copyright 1998-2007, Glenn Randers-Pehrson
+ */
+
+#ifndef MINPRDPNGCONF_H
+#define MINPRDPNGCONF_H
+
+/* To include pngusr.h set -DPNG_USER_CONFIG in CPPFLAGS */
+
+/* List options to turn off features of the build that do not
+ * affect the API (so are not recorded in pnglibconf.h)
+ */
+
+#define PNG_ALIGN_TYPE PNG_ALIGN_NONE
+
+#endif /* MINPRDPNGCONF_H */
--- a/contrib/pngminus/makefile.std
+++ b/contrib/pngminus/makefile.std
@@ -8,9 +8,9 @@ LD=$(CC)
 RM=rm -f

 #PNGPATH = /usr/local
-#PNGINC = -I$(PNGPATH)/include/libpng12
-#PNGLIB = -L$(PNGPATH)/lib -lpng12
-#PNGLIBS = $(PNGPATH)/lib/libpng12.a
+#PNGINC = -I$(PNGPATH)/include/libpng16
+#PNGLIB = -L$(PNGPATH)/lib -lpng16
+#PNGLIBS = $(PNGPATH)/lib/libpng16.a
 PNGINC = -I../..
 PNGLIB = -L../.. -lpng
 PNGLIBS = ../../libpng.a
@@ -23,9 +23,10 @@ ZINC = -I../../../zlib
 ZLIB = -L../../../zlib -lz
 ZLIBS = ../../../zlib/libz.a

-CFLAGS=-O3 $(PNGINC) $(ZINC)
-LDFLAGS=$(PNGLIB) $(ZLIB)
-LDFLAGSS=$(PNGLIBS) $(ZLIBS)
+CPPFLAGS=$(PNGINC) $(ZINC)
+CFLAGS=
+LDLIBS=$(PNGLIB) $(ZLIB)
+LDLIBSS=$(PNGLIBS) $(ZLIBS)
 C=.c
 O=.o
 L=.a
@@ -37,22 +38,22 @@ E=
 all: png2pnm$(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)
-	$(LD) -o png2pnm$(E) png2pnm$(O) $(LDFLAGS) -lm
+	$(LD) $(LDFLAGS) -o png2pnm$(E) png2pnm$(O) $(LDLIBS) -lm

 png2pnm-static$(E): png2pnm$(O)
-	$(LD) -o png2pnm-static$(E) png2pnm$(O) $(LDFLAGSS) -lm
+	$(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)
-	$(LD) -o pnm2png$(E) pnm2png$(O) $(LDFLAGS) -lm
+	$(LD) $(LDFLAGS) -o pnm2png$(E) pnm2png$(O) $(LDLIBS) -lm

 pnm2png-static$(E): pnm2png$(O)
-	$(LD) -o pnm2png-static$(E) pnm2png$(O) $(LDFLAGSS) -lm
+	$(LD) $(LDFLAGS) -o pnm2png-static$(E) pnm2png$(O) $(LDLIBSS) -lm

 clean:
 	$(RM) png2pnm$(O)
--- a/contrib/pngminus/makefile.tc3
+++ b/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
-
--- a/contrib/pngminus/png2pnm.bat
+++ b/contrib/pngminus/png2pnm.bat
--- a/contrib/pngminus/png2pnm.c
+++ b/contrib/pngminus/png2pnm.c
@@ -18,6 +18,7 @@
 #include <mem.h>
 #include <fcntl.h>
 #endif
+#include <zlib.h>

 #ifndef BOOL
 #define BOOL unsigned char
@@ -51,7 +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
@@ -84,7 +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;
@@ -144,7 +147,7 @@ int main(int argc, char *argv[])
  if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
  {
    fprintf (stderr, "PNG2PNM\n");
-    fprintf (stderr, "Error:  unsuccessful convertion of PNG-image\n");
+    fprintf (stderr, "Error:  unsuccessful conversion of PNG-image\n");
    exit(1);
  }

@@ -175,9 +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");
 }

@@ -185,10 +190,11 @@ 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;
+  png_info        *info_ptr = NULL;
  png_byte      buf[8];
  png_byte      *png_pixels = NULL;
  png_byte      **row_pointers = NULL;
@@ -211,13 +217,13 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
  if (ret != 8)
    return FALSE;

-  ret = png_check_sig (buf, 8);
-  if (!ret)
+  ret = png_sig_cmp (buf, 0, 8);
+  if (ret)
    return FALSE;

  /* 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 */
@@ -314,12 +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);
@@ -328,7 +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 */
@@ -371,9 +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++)
      {
@@ -381,7 +389,7 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
          fputc ((int) *pix_ptr++ , pnm_file);
        else
          if (bit_depth == 16){
-	    dep_16 = (long) *pix_ptr++;
+            dep_16 = (long) *pix_ptr++;
            fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++));
          }
          else
@@ -401,9 +409,9 @@ BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL a
            fputc ((int) *pix_ptr++ , alpha_file);
          else
            if (bit_depth == 16){
-	      dep_16 = (long) *pix_ptr++;
+              dep_16 = (long) *pix_ptr++;
              fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
-	    }  
+            }
            else
              fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
        }
--- a/contrib/pngminus/png2pnm.sh
+++ b/contrib/pngminus/png2pnm.sh
--- a/contrib/pngminus/pngminus.bat
+++ b/contrib/pngminus/pngminus.bat
--- a/contrib/pngminus/pngminus.sh
+++ b/contrib/pngminus/pngminus.sh
--- a/contrib/pngminus/pnm2png.bat
+++ b/contrib/pngminus/pnm2png.bat
--- a/contrib/pngminus/pnm2png.c
+++ b/contrib/pngminus/pnm2png.c
@@ -18,6 +18,7 @@
 #include <mem.h>
 #include <fcntl.h>
 #endif
+#include <zlib.h>

 #ifndef BOOL
 #define BOOL unsigned char
@@ -49,7 +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);
@@ -175,7 +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");
 }

@@ -183,29 +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;
-  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;

@@ -218,20 +228,36 @@ 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'))
  {
    raw = (type_token[1] == '5');
    color_type = PNG_COLOR_TYPE_GRAY;
    get_token(pnm_file, width_token);
-    sscanf (width_token, "%lu", &width);
+    sscanf (width_token, "%lu", &ul_width);
+    width = (png_uint_32) ul_width;
    get_token(pnm_file, height_token);
-    sscanf (height_token, "%lu", &height);
+    sscanf (height_token, "%lu", &ul_height);
+    height = (png_uint_32) ul_height;
    get_token(pnm_file, maxval_token);
-    sscanf (maxval_token, "%lu", &maxval);
+    sscanf (maxval_token, "%lu", &ul_maxval);
+    maxval = (png_uint_32) ul_maxval;
+
    if (maxval <= 1)
      bit_depth = 1;
    else if (maxval <= 3)
@@ -248,11 +274,14 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
    raw = (type_token[1] == '6');
    color_type = PNG_COLOR_TYPE_RGB;
    get_token(pnm_file, width_token);
-    sscanf (width_token, "%lu", &width);
+    sscanf (width_token, "%lu", &ul_width);
+    width = (png_uint_32) ul_width;
    get_token(pnm_file, height_token);
-    sscanf (height_token, "%lu", &height);
+    sscanf (height_token, "%lu", &ul_height);
+    height = (png_uint_32) ul_height;
    get_token(pnm_file, maxval_token);
-    sscanf (maxval_token, "%lu", &maxval);
+    sscanf (maxval_token, "%lu", &ul_maxval);
+    maxval = (png_uint_32) ul_maxval;
    if (maxval <= 1)
      bit_depth = 1;
    else if (maxval <= 3)
@@ -287,15 +316,18 @@ BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
    {
      alpha_raw = (type_token[1] == '5');
      get_token(alpha_file, width_token);
-      sscanf (width_token, "%lu", &alpha_width);
+      sscanf (width_token, "%lu", &ul_alpha_width);
+      alpha_width=(png_uint_32) ul_alpha_width;
      if (alpha_width != width)
        return FALSE;
      get_token(alpha_file, height_token);
-      sscanf (height_token, "%lu", &alpha_height);
+      sscanf (height_token, "%lu", &ul_alpha_height);
+      alpha_height = (png_uint_32) ul_alpha_height;
      if (alpha_height != height)
        return FALSE;
      get_token(alpha_file, maxval_token);
-      sscanf (maxval_token, "%lu", &maxval);
+      sscanf (maxval_token, "%lu", &ul_maxval);
+      maxval = (png_uint_32) ul_maxval;
      if (maxval <= 1)
        alpha_depth = 1;
      else if (maxval <= 3)
@@ -329,56 +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;
@@ -390,6 +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)))
  {
@@ -411,7 +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;
@@ -419,13 +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 */
@@ -446,19 +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] != ' '));

@@ -510,6 +580,7 @@ png_uint_32 get_value (FILE *pnm_file, int depth)
 {
  static png_uint_32 mask = 0;
  png_byte token[16];
+  unsigned long ul_ret_value;
  png_uint_32 ret_value;
  int i = 0;

@@ -518,7 +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", &ret_value);
+  sscanf ((const char *) token, "%lu", &ul_ret_value);
+  ret_value = (png_uint_32) ul_ret_value;

  ret_value &= mask;

--- a/contrib/pngminus/pnm2png.sh
+++ b/contrib/pngminus/pnm2png.sh
--- a/contrib/pngsuite/README
+++ b/contrib/pngsuite/README
@@ -1,41 +1,61 @@

 pngsuite
 --------
-(c) Willem van Schaik, 1999
+(c) Willem van Schaik, 1999, 2011, 2012
+Two images are by Glenn Randers-Pehrson, 2012

-Permission to use, copy, and distribute these images for any purpose and
-without fee is hereby granted.
+Permission to use, copy, modify, and distribute these images for any
+purpose and without fee is hereby granted.

-These 15 images are part of the much larger PngSuite test-set of 
-images, available for developers of PNG supporting software. The 
-complete set, available at http:/www.schaik.com/pngsuite/, contains 
+The 15 "bas*.png" images are part of the much larger PngSuite test-set of
+images, available for developers of PNG supporting software. The
+complete set, available at http:/www.schaik.com/pngsuite/, contains
 a variety of images to test interlacing, gamma settings, ancillary
 chunks, etc.

+The "ft*.png" images are "free/libre" replacements for the transparent
+corresponding t*.png images in the PngSuite.
+
 The images in this directory represent the basic PNG color-types:
 grayscale (1-16 bit deep), full color (8 or 16 bit), paletted
 (1-8 bit) and grayscale or color images with alpha channel. You
 can use them to test the proper functioning of PNG software.

-    filename      depth type
+    filename       depth type
    ------------ ------ --------------
-    basn0g01.png  1-bit grayscale
-    basn0g02.png  2-bit grayscale
-    basn0g04.png  4-bit grayscale
-    basn0g08.png  8-bit grayscale
-    basn0g16.png 16-bit grayscale
-    basn2c08.png  8-bit truecolor
-    basn2c16.png 16-bit truecolor
-    basn3p01.png  1-bit paletted
-    basn3p02.png  2-bit paletted
-    basn3p04.png  4-bit paletted
-    basn3p08.png  8-bit paletted
-    basn4a08.png  8-bit gray with alpha
-    basn4a16.png 16-bit gray with alpha
-    basn6a08.png  8-bit RGBA
-    basn6a16.png 16-bit RGBA
+    basn0g01.png   1-bit grayscale
+    basn0g02.png   2-bit grayscale
+    basn0g04.png   4-bit grayscale
+    basn0g08.png   8-bit grayscale
+    basn0g16.png  16-bit grayscale
+    basn2c08.png   8-bit truecolor
+    basn2c16.png  16-bit truecolor
+    basn3p01.png   1-bit paletted
+    basn3p02.png   2-bit paletted
+    basn3p04.png   4-bit paletted
+    basn3p08.png   8-bit paletted
+    basn4a08.png   8-bit gray with alpha
+    basn4a16.png  16-bit gray with alpha
+    basn6a08.png   8-bit RGBA
+    basn6a16.png  16-bit RGBA

-Here is the correct result of typing "pngtest -m *.png" in
+    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
+    ftbgn2c16.png 16-bit truecolor, gray bKGD
+    ftbgn3p08.png  8-bit paletted, gray bKGD
+    ftbrn2c08.png  8-bit truecolor, red bKGD
+    ftbwn0g16.png 16-bit gray, white bKGD
+    ftbwn3p08.png  8-bit paletted, white bKGD
+    ftbyn3p08.png  8-bit paletted, yellow bKGD
+    ftp0n0g08.png  8-bit grayscale, opaque
+    ftp0n2c08.png  8-bit truecolor, opaque
+    ftp0n3p08.png  8-bit paletted, opaque
+    ftp1n3p08.png  8-bit paletted, no bKGD
+
+Here is the correct result of typing "pngtest -m bas*.png" in
 this directory:

 Testing basn0g01.png: PASS (524 zero samples)
--- a/contrib/pngsuite/ftbbn0g01.png
+++ b/contrib/pngsuite/ftbbn0g01.png
--- a/contrib/pngsuite/ftbbn0g02.png
+++ b/contrib/pngsuite/ftbbn0g02.png
--- a/contrib/pngsuite/ftbbn0g04.png
+++ b/contrib/pngsuite/ftbbn0g04.png
--- a/contrib/pngsuite/ftbbn2c16.png
+++ b/contrib/pngsuite/ftbbn2c16.png
--- a/contrib/pngsuite/ftbbn3p08.png
+++ b/contrib/pngsuite/ftbbn3p08.png
--- a/contrib/pngsuite/ftbgn2c16.png
+++ b/contrib/pngsuite/ftbgn2c16.png
--- a/contrib/pngsuite/ftbgn3p08.png
+++ b/contrib/pngsuite/ftbgn3p08.png
--- a/contrib/pngsuite/ftbrn2c08.png
+++ b/contrib/pngsuite/ftbrn2c08.png
--- a/Show More
+++ b/Show More