Upgrading libpng: Adding clean copy of libpng 1.5.10

This commit removes the previous version of the bundled libpng
(1.5.4), as well as all local modifications to it. It adds an
unmodified copy of the official libpng source distribution, except
that various extraneous files have been removed, as usual.

The patches required to build it in Qt will follow in separate
commit(s).

Change-Id: I90149f87fc889c44a3b60b21cdf755020f3a8e39
Reviewed-by: Kim M. Kalland <kim.kalland@nokia.com>

1 files changed, 592 insertions, 158 deletions

diff --git a/src/3rdparty/libpng/pngpriv.h b/src/3rdparty/libpng/pngpriv.h
index e248ad8bbe..e76a57975f 100644
--- a/src/3rdparty/libpng/pngpriv.h
+++ b/src/3rdparty/libpng/pngpriv.h
@@ -2,11 +2,11 @@
 /* pngpriv.h - private declarations for use inside libpng
  *
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2011 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2012 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.5.0 [January 6, 2011]
+ * Last changed in libpng 1.5.10 [March 29, 2012]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -25,16 +25,30 @@
 #ifndef PNGPRIV_H
 #define PNGPRIV_H
 
-#ifdef _MSC_VER
-#  define _CRT_SECURE_NO_DEPRECATE
-#endif
+/* Feature Test Macros.  The following are defined here to ensure that correctly
+ * implemented libraries reveal the APIs libpng needs to build and hide those
+ * that are not needed and potentially damaging to the compilation.
+ *
+ * Feature Test Macros must be defined before any system header is included (see
+ * POSIX 1003.1 2.8.2 "POSIX Symbols."
+ *
+ * These macros only have an effect if the operating system supports either
+ * POSIX 1003.1 or C99, or both.  On other operating systems (particularly
+ * Windows/Visual Studio) there is no effect; the OS specific tests below are
+ * still required (as of 2011-05-02.)
+ */
+#define _POSIX_SOURCE 1 /* Just the POSIX 1003.1 and C89 APIs */
 
 /* This is required for the definition of abort(), used as a last ditch
  * error handler when all else fails.
  */
 #include <stdlib.h>
 
-#define PNGLIB_BUILD
+/* This is used to find 'offsetof', used below for alignment tests. */
+#include <stddef.h>
+
+#define PNGLIB_BUILD /*libpng is being built, not used*/
+
 #ifdef PNG_USER_CONFIG
 #  include "pngusr.h"
    /* These should have been defined in pngusr.h */
@@ -45,10 +59,120 @@
 #    define PNG_USER_DLLFNAME_POSTFIX "Cb"
 #  endif
 #endif
+
+/* Is this a build of a DLL where compilation of the object modules requires
+ * different preprocessor settings to those required for a simple library?  If
+ * so PNG_BUILD_DLL must be set.
+ *
+ * If libpng is used inside a DLL but that DLL does not export the libpng APIs
+ * PNG_BUILD_DLL must not be set.  To avoid the code below kicking in build a
+ * static library of libpng then link the DLL against that.
+ */
+#ifndef PNG_BUILD_DLL
+#  ifdef DLL_EXPORT
+      /* This is set by libtool when files are compiled for a DLL; libtool
+       * always compiles twice, even on systems where it isn't necessary.  Set
+       * PNG_BUILD_DLL in case it is necessary:
+       */
+#     define PNG_BUILD_DLL
+#  else
+#     ifdef _WINDLL
+         /* This is set by the Microsoft Visual Studio IDE in projects that
+          * build a DLL.  It can't easily be removed from those projects (it
+          * isn't visible in the Visual Studio UI) so it is a fairly reliable
+          * indication that PNG_IMPEXP needs to be set to the DLL export
+          * attributes.
+          */
+#        define PNG_BUILD_DLL
+#     else
+#        ifdef __DLL__
+            /* This is set by the Borland C system when compiling for a DLL
+             * (as above.)
+             */
+#           define PNG_BUILD_DLL
+#        else
+            /* Add additional compiler cases here. */
+#        endif
+#     endif
+#  endif
+#endif /* Setting PNG_BUILD_DLL if required */
+
+/* See pngconf.h for more details: the builder of the library may set this on
+ * the command line to the right thing for the specific compilation system or it
+ * may be automagically set above (at present we know of no system where it does
+ * need to be set on the command line.)
+ *
+ * PNG_IMPEXP must be set here when building the library to prevent pngconf.h
+ * setting it to the "import" setting for a DLL build.
+ */
+#ifndef PNG_IMPEXP
+#  ifdef PNG_BUILD_DLL
+#     define PNG_IMPEXP PNG_DLL_EXPORT
+#  else
+      /* Not building a DLL, or the DLL doesn't require specific export
+       * definitions.
+       */
+#     define PNG_IMPEXP
+#  endif
+#endif
+
+/* No warnings for private or deprecated functions in the build: */
+#ifndef PNG_DEPRECATED
+#  define PNG_DEPRECATED
+#endif
+#ifndef PNG_PRIVATE
+#  define PNG_PRIVATE
+#endif
+
 #include "png.h"
 #include "pnginfo.h"
 #include "pngstruct.h"
 
+/* pngconf.h does not set PNG_DLL_EXPORT unless it is required, so: */
+#ifndef PNG_DLL_EXPORT
+#  define PNG_DLL_EXPORT
+#endif
+
+/* SECURITY and SAFETY:
+ *
+ * By default libpng is built without any internal limits on image size,
+ * individual heap (png_malloc) allocations or the total amount of memory used.
+ * If PNG_SAFE_LIMITS_SUPPORTED is defined, however, the limits below are used
+ * (unless individually overridden).  These limits are believed to be fairly
+ * safe, but builders of secure systems should verify the values against the
+ * real system capabilities.
+ */
+
+#ifdef PNG_SAFE_LIMITS_SUPPORTED
+   /* 'safe' limits */
+#  ifndef PNG_USER_WIDTH_MAX
+#     define PNG_USER_WIDTH_MAX 1000000
+#  endif
+#  ifndef PNG_USER_HEIGHT_MAX
+#     define PNG_USER_HEIGHT_MAX 1000000
+#  endif
+#  ifndef PNG_USER_CHUNK_CACHE_MAX
+#     define PNG_USER_CHUNK_CACHE_MAX 128
+#  endif
+#  ifndef PNG_USER_CHUNK_MALLOC_MAX
+#     define PNG_USER_CHUNK_MALLOC_MAX 8000000
+#  endif
+#else
+   /* values for no limits */
+#  ifndef PNG_USER_WIDTH_MAX
+#     define PNG_USER_WIDTH_MAX 0x7fffffff
+#  endif
+#  ifndef PNG_USER_HEIGHT_MAX
+#     define PNG_USER_HEIGHT_MAX 0x7fffffff
+#  endif
+#  ifndef PNG_USER_CHUNK_CACHE_MAX
+#     define PNG_USER_CHUNK_CACHE_MAX 0
+#  endif
+#  ifndef PNG_USER_CHUNK_MALLOC_MAX
+#     define PNG_USER_CHUNK_MALLOC_MAX 0
+#  endif
+#endif
+
 /* This is used for 16 bit gamma tables - only the top level pointers are const,
  * this could be changed:
  */
@@ -87,13 +211,15 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #  define PNG_MAX_MALLOC_64K
 #endif
 
+#ifndef PNG_UNUSED
 /* Unused formal parameter warnings are silenced using the following macro
  * which is expected to have no bad effects on performance (optimizing
  * compilers will probably remove it entirely).  Note that if you replace
  * it with something other than whitespace, you must include the terminating
  * semicolon.
  */
-#define PNG_UNUSED(param) (void)param;
+#  define PNG_UNUSED(param) (void)param;
+#endif
 
 /* Just a little check that someone hasn't tried to define something
  * contradictory.
@@ -103,12 +229,44 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #  define PNG_ZBUF_SIZE 65536L
 #endif
 
-/* If warnings or errors are turned off the code is disabled
- * or redirected here.
+/* PNG_STATIC is used to mark internal file scope functions if they need to be
+ * accessed for implementation tests (see the code in tests/?*).
  */
-#ifndef PNG_WARNINGS_SUPPORTED
-#  define png_warning(s1,s2) ((void)0)
-#  define png_chunk_warning(s1,s2) ((void)0)
+#ifndef PNG_STATIC
+#   define PNG_STATIC static
+#endif
+
+/* C99 restrict is used where possible, to do this 'restrict' is defined as
+ * empty if we can't be sure it is supported.  configure builds have already
+ * done this work.
+ */
+#ifdef PNG_CONFIGURE_LIBPNG
+#  define PNG_RESTRICT restrict
+#else
+   /* Modern compilers support restrict, but assume not for anything not
+    * recognized here:
+    */
+#  if defined __GNUC__ || defined _MSC_VER || defined __WATCOMC__
+#     define PNG_RESTRICT restrict
+#  else
+#     define PNG_RESTRICT
+#  endif
+#endif
+
+/* If warnings or errors are turned off the code is disabled or redirected here.
+ * From 1.5.4 functions have been added to allow very limited formatting of
+ * error and warning messages - this code will also be disabled here.
+ */
+#ifdef PNG_WARNINGS_SUPPORTED
+#  define PNG_WARNING_PARAMETERS(p) png_warning_parameters p;
+#else
+#  define png_warning(s1,s2) ((void)(s1))
+#  define png_chunk_warning(s1,s2) ((void)(s1))
+#  define png_warning_parameter(p,number,string) ((void)0)
+#  define png_warning_parameter_unsigned(p,number,format,value) ((void)0)
+#  define png_warning_parameter_signed(p,number,format,value) ((void)0)
+#  define png_formatted_warning(pp,p,message) ((void)(pp))
+#  define PNG_WARNING_PARAMETERS(p)
 #endif
 #ifndef PNG_ERROR_TEXT_SUPPORTED
 #  define png_error(s1,s2) png_err(s1)
@@ -116,15 +274,28 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #  define png_fixed_error(s1,s2) png_err(s1)
 #endif
 
+/* C allows up-casts from (void*) to any pointer and (const void*) to any
+ * pointer to a const object.  C++ regards this as a type error and requires an
+ * explicit, static, cast and provides the static_cast<> rune to ensure that
+ * const is not cast away.
+ */
+#ifdef __cplusplus
+#  define png_voidcast(type, value) static_cast<type>(value)
+#else
+#  define png_voidcast(type, value) (value)
+#endif /* __cplusplus */
+
 #ifndef PNG_EXTERN
 /* The functions exported by PNG_EXTERN are internal functions, which
  * aren't usually used outside the library (as far as I know), so it is
  * debatable if they should be exported at all.  In the future, when it
  * is possible to have run-time registry of chunk-handling functions,
  * some of these might be made available again.
-#  define PNG_EXTERN extern
+ *
+ * 1.5.7: turned the use of 'extern' back on, since it is localized to pngpriv.h
+ * it should be safe now (it is unclear why it was turned off.)
  */
-#  define PNG_EXTERN
+#  define PNG_EXTERN extern
 #endif
 
 /* Some fixed point APIs are still required even if not exported because
@@ -189,7 +360,7 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 
 /* Memory model/platform independent fns */
 #ifndef PNG_ABORT
-#  if defined(_WINDOWS_) || defined(_WIN32_WCE)
+#  ifdef _WINDOWS_
 #    define PNG_ABORT() ExitProcess(0)
 #  else
 #    define PNG_ABORT() abort()
@@ -202,60 +373,74 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #  define NOCHECK 0
 #  define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
 #  define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
-#  define png_strcpy  _fstrcpy
-#  define png_strncpy _fstrncpy   /* Added to v 1.2.6 */
 #  define png_strlen  _fstrlen
 #  define png_memcmp  _fmemcmp    /* SJT: added */
 #  define png_memcpy  _fmemcpy
 #  define png_memset  _fmemset
-#  define png_sprintf sprintf
 #else
 #  ifdef _WINDOWS_  /* Favor Windows over C runtime fns */
 #    define CVT_PTR(ptr)         (ptr)
 #    define CVT_PTR_NOCHECK(ptr) (ptr)
-#    define png_strcpy  lstrcpyA
-#    define png_strncpy lstrcpynA
 #    define png_strlen  lstrlenA
 #    define png_memcmp  memcmp
 #    define png_memcpy  CopyMemory
 #    define png_memset  memset
-#    define png_sprintf wsprintfA
 #  else
 #    define CVT_PTR(ptr)         (ptr)
 #    define CVT_PTR_NOCHECK(ptr) (ptr)
-#    define png_strcpy  strcpy
-#    define png_strncpy strncpy     /* Added to v 1.2.6 */
 #    define png_strlen  strlen
 #    define png_memcmp  memcmp      /* SJT: added */
 #    define png_memcpy  memcpy
 #    define png_memset  memset
-#    define png_sprintf sprintf
 #  endif
 #endif
-/* End of memory model/platform independent support */
 
-#ifndef PNG_NO_SNPRINTF
-#  ifdef _MSC_VER
-#    define png_snprintf _snprintf   /* Added to v 1.2.19 */
-#    define png_snprintf2 _snprintf
-#    define png_snprintf6 _snprintf
+/* These macros may need to be architecture dependent. */
+#define PNG_ALIGN_NONE   0 /* do not use data alignment */
+#define PNG_ALIGN_ALWAYS 1 /* assume unaligned accesses are OK */
+#ifdef offsetof
+#  define PNG_ALIGN_OFFSET 2 /* use offsetof to determine alignment */
+#else
+#  define PNG_ALIGN_OFFSET -1 /* prevent the use of this */
+#endif
+#define PNG_ALIGN_SIZE   3 /* use sizeof to determine alignment */
+
+#ifndef PNG_ALIGN_TYPE
+   /* Default to using aligned access optimizations and requiring alignment to a
+    * multiple of the data type size.  Override in a compiler specific fashion
+    * if necessary by inserting tests here:
+    */
+#  define PNG_ALIGN_TYPE PNG_ALIGN_SIZE
+#endif
+
+#if PNG_ALIGN_TYPE == PNG_ALIGN_SIZE
+   /* This is used because in some compiler implementations non-aligned
+    * structure members are supported, so the offsetof approach below fails.
+    * Set PNG_ALIGN_TO_SIZE=0 for compiler combinations where unaligned access
+    * is good for performance.  Do not do this unless you have tested the result
+    * and understand it.
+    */
+#  define png_alignof(type) (sizeof (type))
+#else
+#  if PNG_ALIGN_TYPE == PNG_ALIGN_OFFSET
+#     define png_alignof(type) offsetof(struct{char c; type t;}, t)
 #  else
-#    define png_snprintf snprintf   /* Added to v 1.2.19 */
-#    define png_snprintf2 snprintf
-#    define png_snprintf6 snprintf
+#     if PNG_ALIGN_TYPE == PNG_ALIGN_ALWAYS
+#        define png_alignof(type) (1)
+#     endif
+      /* Else leave png_alignof undefined to prevent use thereof */
 #  endif
+#endif
+
+/* This implicitly assumes alignment is always to a power of 2. */
+#ifdef png_alignof
+#  define png_isaligned(ptr, type)\
+   ((((const char*)ptr-(const char*)0) & (png_alignof(type)-1)) == 0)
 #else
-  /* You don't have or don't want to use snprintf().  Caution: Using
-   * sprintf instead of snprintf exposes your application to accidental
-   * or malevolent buffer overflows.  If you don't have snprintf()
-   * as a general rule you should provide one (you can get one from
-   * Portable OpenSSH).
-   */
-#  define png_snprintf(s1,n,fmt,x1) png_sprintf(s1,fmt,x1)
-#  define png_snprintf2(s1,n,fmt,x1,x2) png_sprintf(s1,fmt,x1,x2)
-#  define png_snprintf6(s1,n,fmt,x1,x2,x3,x4,x5,x6) \
-      png_sprintf(s1,fmt,x1,x2,x3,x4,x5,x6)
+#  define png_isaligned(ptr, type) 0
 #endif
+
+/* End of memory model/platform independent support */
 /* End of 1.5.0beta36 move from pngconf.h */
 
 /* CONSTANTS and UTILITY MACROS
@@ -263,12 +448,14 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
  */
 
 /* Various modes of operation.  Note that after an init, mode is set to
- * zero automatically when the structure is created.
+ * zero automatically when the structure is created.  Three of these
+ * are defined in png.h because they need to be visible to applications
+ * that call png_set_unknown_chunk().
  */
-#define PNG_HAVE_IHDR               0x01
-#define PNG_HAVE_PLTE               0x02
+/* #define PNG_HAVE_IHDR            0x01 (defined in png.h) */
+/* #define PNG_HAVE_PLTE            0x02 (defined in png.h) */
 #define PNG_HAVE_IDAT               0x04
-#define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
+/* #define PNG_AFTER_IDAT           0x08 (defined in png.h) */
 #define PNG_HAVE_IEND               0x10
 #define PNG_HAVE_gAMA               0x20
 #define PNG_HAVE_cHRM               0x40
@@ -279,6 +466,7 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_BACKGROUND_IS_GRAY     0x800
 #define PNG_HAVE_PNG_SIGNATURE    0x1000
 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
+#define PNG_HAVE_iCCP             0x4000
 
 /* Flags for the transformations the PNG library does on the image data */
 #define PNG_BGR                 0x0001
@@ -288,32 +476,31 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_SWAP_BYTES          0x0010
 #define PNG_INVERT_MONO         0x0020
 #define PNG_QUANTIZE            0x0040
-#define PNG_BACKGROUND          0x0080
+#define PNG_COMPOSE             0x0080     /* Was PNG_BACKGROUND */
 #define PNG_BACKGROUND_EXPAND   0x0100
-                          /*    0x0200 unused */
-#define PNG_16_TO_8             0x0400
+#define PNG_EXPAND_16           0x0200     /* Added to libpng 1.5.2 */
+#define PNG_16_TO_8             0x0400     /* Becomes 'chop' in 1.5.4 */
 #define PNG_RGBA                0x0800
 #define PNG_EXPAND              0x1000
 #define PNG_GAMMA               0x2000
 #define PNG_GRAY_TO_RGB         0x4000
-#define PNG_FILLER              0x8000L
-#define PNG_PACKSWAP           0x10000L
-#define PNG_SWAP_ALPHA         0x20000L
-#define PNG_STRIP_ALPHA        0x40000L
-#define PNG_INVERT_ALPHA       0x80000L
-#define PNG_USER_TRANSFORM    0x100000L
-#define PNG_RGB_TO_GRAY_ERR   0x200000L
-#define PNG_RGB_TO_GRAY_WARN  0x400000L
-#define PNG_RGB_TO_GRAY       0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
-                       /*     0x800000L     Unused */
-#define PNG_ADD_ALPHA         0x1000000L  /* Added to libpng-1.2.7 */
-#define PNG_EXPAND_tRNS       0x2000000L  /* Added to libpng-1.2.9 */
-                       /*   0x4000000L  unused */
-                       /*   0x8000000L  unused */
-                       /*  0x10000000L  unused */
-                       /*  0x20000000L  unused */
-                       /*  0x40000000L  unused */
-
+#define PNG_FILLER              0x8000
+#define PNG_PACKSWAP           0x10000
+#define PNG_SWAP_ALPHA         0x20000
+#define PNG_STRIP_ALPHA        0x40000
+#define PNG_INVERT_ALPHA       0x80000
+#define PNG_USER_TRANSFORM    0x100000
+#define PNG_RGB_TO_GRAY_ERR   0x200000
+#define PNG_RGB_TO_GRAY_WARN  0x400000
+#define PNG_RGB_TO_GRAY       0x600000 /* two bits, RGB_TO_GRAY_ERR|WARN */
+#define PNG_ENCODE_ALPHA      0x800000 /* Added to libpng-1.5.4 */
+#define PNG_ADD_ALPHA         0x1000000 /* Added to libpng-1.2.7 */
+#define PNG_EXPAND_tRNS       0x2000000 /* Added to libpng-1.2.9 */
+#define PNG_SCALE_16_TO_8     0x4000000 /* Added to libpng-1.5.4 */
+                       /*   0x8000000 unused */
+                       /*  0x10000000 unused */
+                       /*  0x20000000 unused */
+                       /*  0x40000000 unused */
 /* Flags for png_create_struct */
 #define PNG_STRUCT_PNG   0x0001
 #define PNG_STRUCT_INFO  0x0002
@@ -335,25 +522,25 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
-                                /*        0x1000  unused */
-                                /*        0x2000  unused */
-                                /*        0x4000  unused */
-#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
-#define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
-#define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
-#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
-#define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
-#define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
-#define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
-#define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
-#define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000L  /* Added to libpng-1.4.0 */
-                                  /*     0x1000000L  unused */
-                                  /*     0x2000000L  unused */
-                                  /*     0x4000000L  unused */
-                                  /*     0x8000000L  unused */
-                                  /*    0x10000000L  unused */
-                                  /*    0x20000000L  unused */
-                                  /*    0x40000000L  unused */
+#define PNG_FLAG_ASSUME_sRGB              0x1000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_OPTIMIZE_ALPHA           0x2000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_DETECT_UNINITIALIZED     0x4000  /* Added to libpng-1.5.4 */
+#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000
+#define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000
+#define PNG_FLAG_LIBRARY_MISMATCH         0x20000
+#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000
+#define PNG_FLAG_STRIP_ERROR_TEXT         0x80000
+#define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000
+                                  /*      0x200000  unused */
+                                  /*      0x400000  unused */
+#define PNG_FLAG_BENIGN_ERRORS_WARN       0x800000  /* Added to libpng-1.4.0 */
+#define PNG_FLAG_ZTXT_CUSTOM_STRATEGY    0x1000000  /* 5 lines added */
+#define PNG_FLAG_ZTXT_CUSTOM_LEVEL       0x2000000  /* to libpng-1.5.4 */
+#define PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL   0x4000000
+#define PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS 0x8000000
+#define PNG_FLAG_ZTXT_CUSTOM_METHOD      0x10000000
+                                  /*     0x20000000  unused */
+                                  /*     0x40000000  unused */
 
 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
@@ -435,32 +622,75 @@ PNG_EXTERN png_fixed_point png_fixed PNGARG((png_structp png_ptr, double fp,
 #endif
 #endif
 
-/* Constant strings for known chunk types.  If you need to add a chunk,
- * define the name here, and add an invocation of the macro wherever it's
- * needed.
+/* Constants for known chunk types.  If you need to add a chunk, define the name
+ * here.  For historical reasons these constants have the form png_<name>; i.e.
+ * the prefix is lower case.  Please use decimal values as the parameters to
+ * match the ISO PNG specification and to avoid relying on the C locale
+ * interpretation of character values.
+ *
+ * Prior to 1.5.6 these constants were strings, as of 1.5.6 png_uint_32 values
+ * are computed and a new macro (PNG_STRING_FROM_CHUNK) added to allow a string
+ * to be generated if required.
+ *
+ * PNG_32b correctly produces a value shifted by up to 24 bits, even on
+ * architectures where (int) is only 16 bits.
  */
-#define PNG_IHDR PNG_CONST png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
-#define PNG_IDAT PNG_CONST png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
-#define PNG_IEND PNG_CONST png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
-#define PNG_PLTE PNG_CONST png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
-#define PNG_bKGD PNG_CONST png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
-#define PNG_cHRM PNG_CONST png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
-#define PNG_gAMA PNG_CONST png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
-#define PNG_hIST PNG_CONST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
-#define PNG_iCCP PNG_CONST png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
-#define PNG_iTXt PNG_CONST png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
-#define PNG_oFFs PNG_CONST png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
-#define PNG_pCAL PNG_CONST png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
-#define PNG_sCAL PNG_CONST png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
-#define PNG_pHYs PNG_CONST png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
-#define PNG_sBIT PNG_CONST png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
-#define PNG_sPLT PNG_CONST png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
-#define PNG_sRGB PNG_CONST png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
-#define PNG_sTER PNG_CONST png_byte png_sTER[5] = {115,  84,  69,  82, '\0'}
-#define PNG_tEXt PNG_CONST png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
-#define PNG_tIME PNG_CONST png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
-#define PNG_tRNS PNG_CONST png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
-#define PNG_zTXt PNG_CONST png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
+#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
+#define PNG_CHUNK(b1,b2,b3,b4) \
+   (PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
+
+#define png_IHDR PNG_CHUNK( 73,  72,  68,  82)
+#define png_IDAT PNG_CHUNK( 73,  68,  65,  84)
+#define png_IEND PNG_CHUNK( 73,  69,  78,  68)
+#define png_PLTE PNG_CHUNK( 80,  76,  84,  69)
+#define png_bKGD PNG_CHUNK( 98,  75,  71,  68)
+#define png_cHRM PNG_CHUNK( 99,  72,  82,  77)
+#define png_gAMA PNG_CHUNK(103,  65,  77,  65)
+#define png_hIST PNG_CHUNK(104,  73,  83,  84)
+#define png_iCCP PNG_CHUNK(105,  67,  67,  80)
+#define png_iTXt PNG_CHUNK(105,  84,  88, 116)
+#define png_oFFs PNG_CHUNK(111,  70,  70, 115)
+#define png_pCAL PNG_CHUNK(112,  67,  65,  76)
+#define png_sCAL PNG_CHUNK(115,  67,  65,  76)
+#define png_pHYs PNG_CHUNK(112,  72,  89, 115)
+#define png_sBIT PNG_CHUNK(115,  66,  73,  84)
+#define png_sPLT PNG_CHUNK(115,  80,  76,  84)
+#define png_sRGB PNG_CHUNK(115,  82,  71,  66)
+#define png_sTER PNG_CHUNK(115,  84,  69,  82)
+#define png_tEXt PNG_CHUNK(116,  69,  88, 116)
+#define png_tIME PNG_CHUNK(116,  73,  77,  69)
+#define png_tRNS PNG_CHUNK(116,  82,  78,  83)
+#define png_zTXt PNG_CHUNK(122,  84,  88, 116)
+
+/* The following will work on (signed char*) strings, whereas the get_uint_32
+ * macro will fail on top-bit-set values because of the sign extension.
+ */
+#define PNG_CHUNK_FROM_STRING(s)\
+   PNG_CHUNK(0xff&(s)[0], 0xff&(s)[1], 0xff&(s)[2], 0xff&(s)[3])
+
+/* This uses (char), not (png_byte) to avoid warnings on systems where (char) is
+ * signed and the argument is a (char[])  This macro will fail miserably on
+ * systems where (char) is more than 8 bits.
+ */
+#define PNG_STRING_FROM_CHUNK(s,c)\
+   (void)(((char*)(s))[0]=(char)((c)>>24), ((char*)(s))[1]=(char)((c)>>16),\
+   ((char*)(s))[2]=(char)((c)>>8), ((char*)(s))[3]=(char)((c)))
+
+/* Do the same but terminate with a null character. */
+#define PNG_CSTRING_FROM_CHUNK(s,c)\
+   (void)(PNG_STRING_FROM_CHUNK(s,c), ((char*)(s))[4] = 0)
+
+/* Test on flag values as defined in the spec (section 5.4): */
+#define PNG_CHUNK_ANCILLIARY(c)   (1 & ((c) >> 29))
+#define PNG_CHUNK_CRITICAL(c)     (!PNG_CHUNK_ANCILLIARY(c))
+#define PNG_CHUNK_PRIVATE(c)      (1 & ((c) >> 21))
+#define PNG_CHUNK_RESERVED(c)     (1 & ((c) >> 13))
+#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >>  5))
+
+/* Gamma values (new at libpng-1.5.4): */
+#define PNG_GAMMA_MAC_OLD 151724  /* Assume '1.8' is really 2.2/1.45! */
+#define PNG_GAMMA_MAC_INVERSE 65909
+#define PNG_GAMMA_sRGB_INVERSE 45455
 
 
 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
@@ -474,6 +704,12 @@ extern "C" {
  * be found in the files where the functions are located.
  */
 
+/* Check the user version string for compatibility, returns false if the version
+ * numbers aren't compatible.
+ */
+PNG_EXTERN int png_user_version_check(png_structp png_ptr,
+   png_const_charp user_png_ver);
+
 /* Allocate memory for an internal libpng struct */
 PNG_EXTERN PNG_FUNCTION(png_voidp,png_create_struct,PNGARG((int type)),
    PNG_ALLOCATED);
@@ -542,8 +778,7 @@ PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
     png_size_t length));
 
 /* Decompress data in a chunk that uses compression */
-#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
-    defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
+#if defined(PNG_READ_COMPRESSED_TEXT_SUPPORTED)
 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
     int comp_type, png_size_t chunklength, png_size_t prefix_length,
     png_size_t *data_length));
@@ -646,6 +881,7 @@ PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr,
     png_const_uint_16p hist, int num_hist));
 #endif
 
+/* Chunks that have keywords */
 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
@@ -706,17 +942,44 @@ PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
 /* Internal use only.   Called before first row of data */
 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
 
-/* Combine a row of data, dealing with alpha, etc. if requested */
+/* Combine a row of data, dealing with alpha, etc. if requested.  'row' is an
+ * array of png_ptr->width pixels.  If the image is not interlaced or this
+ * is the final pass this just does a png_memcpy, otherwise the "display" flag
+ * is used to determine whether to copy pixels that are not in the current pass.
+ *
+ * Because 'png_do_read_interlace' (below) replicates pixels this allows this
+ * function to achieve the documented 'blocky' appearance during interlaced read
+ * if display is 1 and the 'sparkle' appearance, where existing pixels in 'row'
+ * are not changed if they are not in the current pass, when display is 0.
+ *
+ * 'display' must be 0 or 1, otherwise the memcpy will be done regardless.
+ *
+ * The API always reads from the png_struct row buffer and always assumes that
+ * it is full width (png_do_read_interlace has already been called.)
+ *
+ * This function is only ever used to write to row buffers provided by the
+ * caller of the relevant libpng API and the row must have already been
+ * transformed by the read transformations.
+ *
+ * The PNG_USE_COMPILE_TIME_MASKS option causes generation of pre-computed
+ * bitmasks for use within the code, otherwise runtime generated masks are used.
+ * The default is compile time masks.
+ */
+#ifndef PNG_USE_COMPILE_TIME_MASKS
+#  define PNG_USE_COMPILE_TIME_MASKS 1
+#endif
 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
-    int mask));
+    int display));
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
-/* Expand an interlaced row */
-/* OLD pre-1.0.9 interface:
+/* Expand an interlaced row: the 'row_info' describes the pass data that has
+ * been read in and must correspond to the pixels in 'row', the pixels are
+ * expanded (moved apart) in 'row' to match the final layout, when doing this
+ * the pixels are *replicated* to the intervening space.  This is essential for
+ * the correct operation of png_combine_row, above.
+ */
 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
     png_bytep row, int pass, png_uint_32 transformations));
- */
-PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
 #endif
 
 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
@@ -727,26 +990,42 @@ PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
     png_bytep row, int pass));
 #endif
 
-/* Unfilter a row */
-PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
-    png_row_infop row_info, png_bytep row, png_const_bytep prev_row,
-    int filter));
+/* Unfilter a row: check the filter value before calling this, there is no point
+ * calling it for PNG_FILTER_VALUE_NONE.
+ */
+PNG_EXTERN void png_read_filter_row PNGARG((png_structp pp, png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row, int filter));
+
+PNG_EXTERN void png_read_filter_row_up_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_sub3_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_sub4_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_avg3_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_avg4_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_paeth3_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
+PNG_EXTERN void png_read_filter_row_paeth4_neon PNGARG((png_row_infop row_info,
+    png_bytep row, png_const_bytep prev_row));
 
 /* Choose the best filter to use and filter the row data */
 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
     png_row_infop row_info));
 
-/* Write out the filtered row. */
-PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
-    png_bytep filtered_row));
 /* Finish a row while reading, dealing with interlacing passes, etc. */
 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
 
 /* Initialize the row buffers, etc. */
 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
+
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 /* Optional call to update the users info structure */
 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
     png_infop info_ptr));
+#endif
 
 /* These are the functions that do the transformations */
 #ifdef PNG_READ_FILLER_SUPPORTED
@@ -776,8 +1055,8 @@ PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
 
 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
-PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
-    png_bytep row, png_uint_32 flags));
+PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info,
+    png_bytep row, int at_start));
 #endif
 
 #ifdef PNG_16BIT_SUPPORTED
@@ -818,7 +1097,12 @@ PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
     png_bytep row));
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+PNG_EXTERN void png_do_scale_16_to_8 PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
     png_bytep row));
 #endif
@@ -849,26 +1133,20 @@ PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info,
     png_bytep row, png_const_color_8p bit_depth));
 #endif
 
-#ifdef PNG_READ_BACKGROUND_SUPPORTED
-#  ifdef PNG_READ_GAMMA_SUPPORTED
-PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_color_16p trans_color,
-    png_const_color_16p background, png_const_color_16p background_1,
-    png_const_bytep gamma_table, png_const_bytep gamma_from_1,
-    png_const_bytep gamma_to_1, png_const_uint_16pp gamma_16,
-    png_const_uint_16pp gamma_16_from_1, png_const_uint_16pp gamma_16_to_1,
-    int gamma_shift));
-#  else
-PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_color_16p trans_color,
-    png_const_color_16p background));
-#  endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
+    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
+PNG_EXTERN void png_do_compose PNGARG((png_row_infop row_info,
+    png_bytep row, png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info,
-    png_bytep row, png_const_bytep gamma_table,
-    png_const_uint_16pp gamma_16_table, int gamma_shift));
+    png_bytep row, png_structp png_ptr));
+#endif
+
+#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
+PNG_EXTERN void png_do_encode_alpha PNGARG((png_row_infop row_info,
+   png_bytep row, png_structp png_ptr));
 #endif
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
@@ -879,6 +1157,11 @@ PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
     png_bytep row, png_const_color_16p trans_color));
 #endif
 
+#ifdef PNG_READ_EXPAND_16_SUPPORTED
+PNG_EXTERN void png_do_expand_16 PNGARG((png_row_infop row_info,
+    png_bytep row));
+#endif
+
 /* The following decodes the appropriate chunks, and does error correction,
  * then calls the appropriate callback for the chunk if it is valid.
  */
@@ -976,17 +1259,35 @@ PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
     png_uint_32 length));
 #endif
 
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
     png_infop info_ptr, png_uint_32 length));
+#endif
 
 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
-    png_const_bytep chunk_name));
+    png_uint_32 chunk_name));
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+/* Exactly as png_handle_as_unknown() except that the argument is a 32-bit chunk
+ * name, not a string.
+ */
+PNG_EXTERN int png_chunk_unknown_handling PNGARG((png_structp png_ptr,
+    png_uint_32 chunk_name));
+#endif
 
 /* Handle the transformations for reading and writing */
-PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
-PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
+PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr,
+   png_row_infop row_info));
+#endif
+#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
+PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr,
+   png_row_infop row_info));
+#endif
 
+#ifdef PNG_READ_TRANSFORMS_SUPPORTED
 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
+#endif
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
@@ -1060,12 +1361,48 @@ PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
     unsigned long *hi_product, unsigned long *lo_product));
 #endif
 
+#ifdef PNG_cHRM_SUPPORTED
+/* Added at libpng version 1.5.5 */
+typedef struct png_xy
+{
+   png_fixed_point redx, redy;
+   png_fixed_point greenx, greeny;
+   png_fixed_point bluex, bluey;
+   png_fixed_point whitex, whitey;
+} png_xy;
+
+typedef struct png_XYZ
+{
+   png_fixed_point redX, redY, redZ;
+   png_fixed_point greenX, greenY, greenZ;
+   png_fixed_point blueX, blueY, blueZ;
+} png_XYZ;
+
+/* The conversion APIs return 0 on success, non-zero on a parameter error. They
+ * allow conversion between the above representations of a color encoding.  When
+ * converting from XYZ end points to chromaticities the absolute magnitude of
+ * the end points is lost, when converting back the sum of the Y values of the
+ * three end points will be 1.0
+ */
+PNG_EXTERN int png_xy_from_XYZ PNGARG((png_xy *xy, png_XYZ XYZ));
+PNG_EXTERN int png_XYZ_from_xy PNGARG((png_XYZ *XYZ, png_xy xy));
+PNG_EXTERN int png_XYZ_from_xy_checked PNGARG((png_structp png_ptr,
+   png_XYZ *XYZ, png_xy xy));
+#endif
+
 /* Added at libpng version 1.4.0 */
 PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
     png_uint_32 width, png_uint_32 height, int bit_depth,
     int color_type, int interlace_type, int compression_type,
     int filter_type));
 
+/* Added at libpng version 1.5.10 */
+#if defined(PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED) || \
+    defined(PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED)
+PNG_EXTERN void png_do_check_palette_indexes PNGARG((png_structp png_ptr,
+    png_row_infop row_info));
+#endif
+
 /* Free all memory used by the read (old method - NOT DLL EXPORTED) */
 PNG_EXTERN void png_read_destroy PNGARG((png_structp png_ptr,
     png_infop info_ptr, png_infop end_info_ptr));
@@ -1083,6 +1420,76 @@ PNG_EXTERN PNG_FUNCTION(void, png_fixed_error, (png_structp png_ptr,
    png_const_charp name),PNG_NORETURN);
 #endif
 
+/* Puts 'string' into 'buffer' at buffer[pos], taking care never to overwrite
+ * the end.  Always leaves the buffer nul terminated.  Never errors out (and
+ * there is no error code.)
+ */
+PNG_EXTERN size_t png_safecat(png_charp buffer, size_t bufsize, size_t pos,
+    png_const_charp string);
+
+/* Various internal functions to handle formatted warning messages, currently
+ * only implemented for warnings.
+ */
+#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Utility to dump an unsigned value into a buffer, given a start pointer and
+ * and end pointer (which should point just *beyond* the end of the buffer!)
+ * Returns the pointer to the start of the formatted string.  This utility only
+ * does unsigned values.
+ */
+PNG_EXTERN png_charp png_format_number(png_const_charp start, png_charp end,
+   int format, png_alloc_size_t number);
+
+/* Convenience macro that takes an array: */
+#define PNG_FORMAT_NUMBER(buffer,format,number) \
+   png_format_number(buffer, buffer + (sizeof buffer), format, number)
+
+/* Suggested size for a number buffer (enough for 64 bits and a sign!) */
+#define PNG_NUMBER_BUFFER_SIZE 24
+
+/* These are the integer formats currently supported, the name is formed from
+ * the standard printf(3) format string.
+ */
+#define PNG_NUMBER_FORMAT_u     1 /* chose unsigned API! */
+#define PNG_NUMBER_FORMAT_02u   2
+#define PNG_NUMBER_FORMAT_d     1 /* chose signed API! */
+#define PNG_NUMBER_FORMAT_02d   2
+#define PNG_NUMBER_FORMAT_x     3
+#define PNG_NUMBER_FORMAT_02x   4
+#define PNG_NUMBER_FORMAT_fixed 5 /* choose the signed API */
+#endif
+
+#ifdef PNG_WARNINGS_SUPPORTED
+/* New defines and members adding in libpng-1.5.4 */
+#  define PNG_WARNING_PARAMETER_SIZE 32
+#  define PNG_WARNING_PARAMETER_COUNT 8
+
+/* An l-value of this type has to be passed to the APIs below to cache the
+ * values of the parameters to a formatted warning message.
+ */
+typedef char png_warning_parameters[PNG_WARNING_PARAMETER_COUNT][
+   PNG_WARNING_PARAMETER_SIZE];
+
+PNG_EXTERN void png_warning_parameter(png_warning_parameters p, int number,
+    png_const_charp string);
+    /* Parameters are limited in size to PNG_WARNING_PARAMETER_SIZE characters,
+     * including the trailing '\0'.
+     */
+PNG_EXTERN void png_warning_parameter_unsigned(png_warning_parameters p,
+    int number, int format, png_alloc_size_t value);
+    /* Use png_alloc_size_t because it is an unsigned type as big as any we
+     * need to output.  Use the following for a signed value.
+     */
+PNG_EXTERN void png_warning_parameter_signed(png_warning_parameters p,
+    int number, int format, png_int_32 value);
+
+PNG_EXTERN void png_formatted_warning(png_structp png_ptr,
+    png_warning_parameters p, png_const_charp message);
+    /* 'message' follows the X/Open approach of using @1, @2 to insert
+     * parameters previously supplied using the above functions.  Errors in
+     * specifying the paramters will simple result in garbage substitutions.
+     */
+#endif
+
 /* ASCII to FP interfaces, currently only implemented if sCAL
  * support is required.
  */
@@ -1145,8 +1552,18 @@ PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
 #define PNG_FP_SAW_DOT   16  /* Saw a dot in current state */
 #define PNG_FP_SAW_E     32  /* Saw an E (or e) in current state */
 #define PNG_FP_SAW_ANY   60  /* Saw any of the above 4 */
+
+/* These three values don't affect the parser.  They are set but not used.
+ */
 #define PNG_FP_WAS_VALID 64  /* Preceding substring is a valid fp number */
-#define PNG_FP_INVALID  128  /* Available for callers as a distinct value */
+#define PNG_FP_NEGATIVE 128  /* A negative number, including "-0" */
+#define PNG_FP_NONZERO  256  /* A non-zero value */
+#define PNG_FP_STICKY   448  /* The above three flags */
+
+/* This is available for the caller to store in 'state' if required.  Do not
+ * call the parser after setting it (the parser sometimes clears it.)
+ */
+#define PNG_FP_INVALID  512  /* Available for callers as a distinct value */
 
 /* Result codes for the parser (boolean - true meants ok, false means
  * not ok yet.)
@@ -1154,6 +1571,20 @@ PNG_EXTERN void png_ascii_from_fixed PNGARG((png_structp png_ptr,
 #define PNG_FP_MAYBE      0  /* The number may be valid in the future */
 #define PNG_FP_OK         1  /* The number is valid */
 
+/* Tests on the sticky non-zero and negative flags.  To pass these checks
+ * the state must also indicate that the whole number is valid - this is
+ * achieved by testing PNG_FP_SAW_DIGIT (see the implementation for why this
+ * is equivalent to PNG_FP_OK above.)
+ */
+#define PNG_FP_NZ_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NEGATIVE | PNG_FP_NONZERO)
+   /* NZ_MASK: the string is valid and a non-zero negative value */
+#define PNG_FP_Z_MASK (PNG_FP_SAW_DIGIT | PNG_FP_NONZERO)
+   /* Z MASK: the string is valid and a non-zero value. */
+   /* PNG_FP_SAW_DIGIT: the string is valid. */
+#define PNG_FP_IS_ZERO(state) (((state) & PNG_FP_Z_MASK) == PNG_FP_SAW_DIGIT)
+#define PNG_FP_IS_POSITIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_Z_MASK)
+#define PNG_FP_IS_NEGATIVE(state) (((state) & PNG_FP_NZ_MASK) == PNG_FP_NZ_MASK)
+ 
 /* The actual parser.  This can be called repeatedly, it updates
  * the index into the string and the state variable (which must
  * be initialzed to 0).  It returns a result code, as above.  There
@@ -1173,7 +1604,10 @@ PNG_EXTERN int png_check_fp_number PNGARG((png_const_charp string,
     png_size_t size, int *statep, png_size_tp whereami));
 
 /* This is the same but it checks a complete string and returns true
- * only if it just contains a floating point number.
+ * only if it just contains a floating point number.  As of 1.5.4 this
+ * function also returns the state at the end of parsing the number if
+ * it was valid (otherwise it returns 0.)  This can be used for testing
+ * for negative or zero values using the sticky flag.
  */
 PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
     png_size_t size));
@@ -1188,13 +1622,13 @@ PNG_EXTERN int png_check_fp_string PNGARG((png_const_charp string,
  * holds the result.
  */
 PNG_EXTERN int png_muldiv PNGARG((png_fixed_point_p res, png_fixed_point a,
-    png_int_32 times, png_int_32 div));
+    png_int_32 multiplied_by, png_int_32 divided_by));
 #endif
 
 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_INCH_CONVERSIONS_SUPPORTED)
 /* Same deal, but issue a warning on overflow and return 0. */
 PNG_EXTERN png_fixed_point png_muldiv_warn PNGARG((png_structp png_ptr,
-    png_fixed_point a, png_int_32 times, png_int_32 div));
+    png_fixed_point a, png_int_32 multiplied_by, png_int_32 divided_by));
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
@@ -1221,19 +1655,19 @@ PNG_EXTERN png_fixed_point png_reciprocal2 PNGARG((png_fixed_point a,
  * correct bit value - 0..255 or 0..65535 as required.
  */
 PNG_EXTERN png_uint_16 png_gamma_correct PNGARG((png_structp png_ptr,
-    unsigned int value, png_fixed_point gamma));
-PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma));
+    unsigned int value, png_fixed_point gamma_value));
+PNG_EXTERN int png_gamma_significant PNGARG((png_fixed_point gamma_value));
 PNG_EXTERN png_uint_16 png_gamma_16bit_correct PNGARG((unsigned int value,
-    png_fixed_point gamma));
+    png_fixed_point gamma_value));
 PNG_EXTERN png_byte png_gamma_8bit_correct PNGARG((unsigned int value,
-    png_fixed_point gamma));
+    png_fixed_point gamma_value));
+PNG_EXTERN void png_destroy_gamma_table(png_structp png_ptr);
 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr,
     int bit_depth));
 #endif
 
 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
 
-
 #include "pngdebug.h"
 
 #ifdef __cplusplus