Update libpng to 1.2.33.

Review URL: http://codereview.chromium.org/15041

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7230 0039d316-1c4b-4281-b951-d872f2087c98

20 files changed, 1368 insertions, 974 deletions

diff --git a/third_party/libpng/LICENSE b/third_party/libpng/LICENSE
index 072d9ef..ac395e8 100644
--- a/third_party/libpng/LICENSE
+++ b/third_party/libpng/LICENSE
@@ -8,7 +8,7 @@ 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 1.2.29, May 8, 2008, are
+libpng versions 1.2.6, August 15, 2004, through 1.2.33, October 31, 2008, are
 Copyright (c) 2004, 2006-2008 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 +106,4 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-May 8, 2008
+October 31, 2008
diff --git a/third_party/libpng/README b/third_party/libpng/README
new file mode 100644
index 0000000..df370be
--- /dev/null
+++ b/third_party/libpng/README
@@ -0,0 +1,267 @@
+README for libpng version 1.2.33 - October 31, 2008 (shared library 12.0)
+See the note about version numbers near the top of png.h
+
+See INSTALL for instructions on how to install libpng.
+
+Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
+libpng-*.tar.lzma, or libpng-*.tar.bz2 if you want UNIX-style line
+endings in the text files, or lpng*.7z or lpng*.zip if you want DOS-style
+line endings.  You can get UNIX-style line endings from the *.zip file
+by using "unzip -a" but there seems to be no simple way to recover
+UNIX-style line endings from the *.7z file.  The *.tar.lzma file is
+recommended for *NIX users instead.
+
+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
+extensive use and testing since mid-1995.  By late 1997 it had
+finally gotten to the stage where there hadn't been significant
+changes to the API in some time, and people have a bad feeling about
+libraries with versions < 1.0.  Version 1.0.0 was released in
+March 1998.
+
+****
+Note that some of the changes to the png_info structure render this
+version of the library binary incompatible with libpng-0.89 or
+earlier versions if you are using a shared library.  The type of the
+"filler" parameter for png_set_filler() has changed from png_byte to
+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,
+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
+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.
+****
+
+Additions since 0.90 include the ability to compile libpng as a
+Windows DLL, and new APIs for accessing data in the info struct.
+Experimental functions include the ability to set weighting and cost
+factors for row filter selection, direct reads of integers from buffers
+on big-endian processors that support misaligned data access, faster
+methods of doing alpha composition, and more accurate 16->8 bit color
+conversion.
+
+The additions since 0.89 include the ability to read from a PNG stream
+which has had some (or all) of the signature bytes read by the calling
+application.  This also allows the reading of embedded PNG streams that
+do not have the PNG file signature.  As well, it is now possible to set
+the library action on the detection of chunk CRC errors.  It is possible
+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-mng-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
+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
+libpng) and zlib's restrictions, see zlib.h
+
+I have included a general makefile, as well as several machine and
+compiler specific ones, but you may have to modify one for your own needs.
+
+You should use zlib 1.0.4 or later to run this, but it MAY work with
+versions as old as zlib 0.95.  Even so, there are bugs in older zlib
+versions which can cause the output of invalid compression streams for
+some images.  You will definitely need zlib 1.0.4 or later if you are
+taking advantage of the MS-DOS "far" structure allocation for the small
+and medium memory models.  You should also note that zlib is a
+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.simplesystems.org/pub/png/src/
+
+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/pngdocs.html
+
+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.
+
+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,
+and any modifications you needed to make to get libpng to compile,
+along with a #define variable to tell what compiler/system you are on.
+If you needed to add transformations to libpng, or wish libpng would
+provide the image in a different way, drop me a note (and code, if
+possible), so I can consider supporting the transformation.
+Finally, if you get any warning messages when compiling libpng
+(note: not zlib), and they are easy to fix, I'd appreciate the
+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.
+
+Send comments/corrections/commendations to png-mng-implement at lists.sf.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-mng-implement list, however.
+
+Please do not send general questions about PNG.  Send them to
+the (png-mng-misc at lists.sourceforge.net, subscription required, visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement to subscribe)
+On the other hand,
+please do not send libpng questions to that address, send them to me
+or to the png-mng-implement list.  I'll
+get them in the end anyway.  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 twelve 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.
+
+Files in this distribution:
+
+      ANNOUNCE      =>  Announcement of this version, with recent changes
+      CHANGES       =>  Description of changes between libpng versions
+      KNOWNBUG      =>  List of known bugs and deficiencies
+      LICENSE       =>  License to use and redistribute libpng
+      README        =>  This file
+      TODO          =>  Things not implemented in the current library
+      Y2KINFO       =>  Statement of Y2K compliance
+      example.c     =>  Example code for using libpng functions
+      libpng-*-*-diff.txt => Diff from previous release
+      libpng.3      =>  manual page for libpng (includes libpng.txt)
+      libpng.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
+      pngerror.c    =>  Error/warning message I/O functions
+      pngget.c      =>  Functions for retrieving info from struct
+      pngmem.c      =>  Memory handling functions
+      pngbar.png    =>  PNG logo, 88x31
+      pngnow.png    =>  PNG logo, 98x31
+      pngpread.c    =>  Progressive reading functions
+      pngread.c     =>  Read data/helper high-level functions
+      pngrio.c      =>  Lowest-level data read I/O functions
+      pngrtran.c    =>  Read data transformation functions
+      pngrutil.c    =>  Read data utility functions
+      pngset.c      =>  Functions for storing data into the info_struct
+      pngtest.c     =>  Library test program
+      pngtest.png   =>  Library test sample image
+      pngtrans.c    =>  Common data transformation functions
+      pngwio.c      =>  Lowest-level write I/O functions
+      pngwrite.c    =>  High-level write functions
+      pngwtran.c    =>  Write data transformations
+      pngwutil.c    =>  Write utility functions
+      contrib       =>  Contributions
+       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
+      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.0.1.2.33)
+       makefile.linux   =>  Linux/ELF makefile
+                            (gcc, creates libpng12.so.0.1.2.33)
+       makefile.gcmmx   =>  Linux/ELF makefile
+                            (gcc, creates libpng12.so.0.1.2.33,
+                            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.0.1.2.33)
+       makefile.sunos   =>  Sun makefile
+       makefile.solaris =>  Solaris 2.X makefile
+                            (gcc, creates libpng12.so.0.1.2.33)
+       makefile.so9     =>  Solaris 9 makefile
+                            (gcc, creates libpng12.so.0.1.2.33)
+       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
+
+Good luck, and happy coding.
+
+-Glenn Randers-Pehrson (current maintainer)
+ Internet: glennrp at users.sourceforge.net
+
+-Andreas Eric Dilger (former maintainer, 1996-1997)
+ Internet: adilger at enel.ucalgary.ca
+ Web: http://members.shaw.ca/adilger/
+
+-Guy Eric Schalnat (original author and former maintainer, 1995-1996)
+ (formerly of Group 42, Inc)
+ Internet: gschal at infinet.com
diff --git a/third_party/libpng/README.google b/third_party/libpng/README.google
index 50fbfa5..96c0d5f 100644
--- a/third_party/libpng/README.google
+++ b/third_party/libpng/README.google
@@ -2,6 +2,7 @@ Our custom configuration options are defined in pngusr.h. This was previously
 called mozpngconf.h, which was copied from Mozilla and modified by Apple (hence
 the webkit_* names).
 
-Updated to 1.2.29, no changes to the source files at all.
+Updated to 1.2.33, no changes to the source files but all unneeded files
+stripped.
 
 http://www.libpng.org/pub/png/libpng.html
diff --git a/third_party/libpng/png.c b/third_party/libpng/png.c
index 63ae86e..385f8bd 100644
--- a/third_party/libpng/png.c
+++ b/third_party/libpng/png.c
@@ -1,9 +1,9 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.2.21 October 4, 2007
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2007 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2008 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.)
  */
@@ -13,7 +13,7 @@
 #include "png.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_2_29 Your_png_h_is_not_version_1_2_29;
+typedef version_1_2_33 Your_png_h_is_not_version_1_2_33;
 
 /* Version information for C files.  This had better match the version
  * string defined in png.h.  */
@@ -92,7 +92,7 @@ PNG_CONST int FARDATA png_pass_dsp_mask[]
 void PNGAPI
 png_set_sig_bytes(png_structp png_ptr, int num_bytes)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_debug(1, "in png_set_sig_bytes\n");
    if (num_bytes > 8)
       png_error(png_ptr, "Too many bytes for PNG signature.");
@@ -153,7 +153,7 @@ png_zalloc(voidpf png_ptr, uInt items, uInt size)
    png_uint_32 save_flags=p->flags;
    png_uint_32 num_bytes;
 
-   if(png_ptr == NULL) return (NULL);
+   if (png_ptr == NULL) return (NULL);
    if (items > PNG_UINT_32_MAX/size)
    {
      png_warning (p, "Potential overflow in png_zalloc()");
@@ -241,7 +241,7 @@ png_create_info_struct(png_structp png_ptr)
    png_infop info_ptr;
 
    png_debug(1, "in png_create_info_struct\n");
-   if(png_ptr == NULL) return (NULL);
+   if (png_ptr == NULL) return (NULL);
 #ifdef PNG_USER_MEM_SUPPORTED
    info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
       png_ptr->malloc_fn, png_ptr->mem_ptr);
@@ -263,7 +263,7 @@ void PNGAPI
 png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
 {
    png_infop info_ptr = NULL;
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 
    png_debug(1, "in png_destroy_info_struct\n");
    if (info_ptr_ptr != NULL)
@@ -302,11 +302,11 @@ png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
 {
    png_infop info_ptr = *ptr_ptr;
 
-   if(info_ptr == NULL) return;
+   if (info_ptr == NULL) return;
 
    png_debug(1, "in png_info_init_3\n");
 
-   if(png_sizeof(png_info) > png_info_struct_size)
+   if (png_sizeof(png_info) > png_info_struct_size)
      {
        png_destroy_struct(info_ptr);
        info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
@@ -314,7 +314,7 @@ png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
      }
 
    /* set everything to 0 */
-   png_memset(info_ptr, 0, png_sizeof (png_info));
+   png_memset(info_ptr, 0, png_sizeof(png_info));
 }
 
 #ifdef PNG_FREE_ME_SUPPORTED
@@ -325,9 +325,9 @@ png_data_freer(png_structp png_ptr, png_infop info_ptr,
    png_debug(1, "in png_data_freer\n");
    if (png_ptr == NULL || info_ptr == NULL)
       return;
-   if(freer == PNG_DESTROY_WILL_FREE_DATA)
+   if (freer == PNG_DESTROY_WILL_FREE_DATA)
       info_ptr->free_me |= mask;
-   else if(freer == PNG_USER_WILL_FREE_DATA)
+   else if (freer == PNG_USER_WILL_FREE_DATA)
       info_ptr->free_me &= ~mask;
    else
       png_warning(png_ptr,
@@ -380,11 +380,11 @@ if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
 #endif
 {
     png_free(png_ptr, info_ptr->trans);
+    info_ptr->trans = NULL;
     info_ptr->valid &= ~PNG_INFO_tRNS;
 #ifndef PNG_FREE_ME_SUPPORTED
     png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
 #endif
-    info_ptr->trans = NULL;
 }
 #endif
 
@@ -459,7 +459,7 @@ if (mask & PNG_FREE_SPLT)
 {
    if (num != -1)
    {
-      if(info_ptr->splt_palettes)
+      if (info_ptr->splt_palettes)
       {
           png_free(png_ptr, info_ptr->splt_palettes[num].name);
           png_free(png_ptr, info_ptr->splt_palettes[num].entries);
@@ -469,7 +469,7 @@ if (mask & PNG_FREE_SPLT)
    }
    else
    {
-       if(info_ptr->splt_palettes_num)
+       if (info_ptr->splt_palettes_num)
        {
          int i;
          for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
@@ -485,11 +485,12 @@ if (mask & PNG_FREE_SPLT)
 #endif
 
 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
-  if(png_ptr->unknown_chunk.data)
+  if (png_ptr->unknown_chunk.data)
   {
     png_free(png_ptr, png_ptr->unknown_chunk.data);
     png_ptr->unknown_chunk.data = NULL;
   }
+
 #ifdef PNG_FREE_ME_SUPPORTED
 if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
 #else
@@ -498,7 +499,7 @@ if (mask & PNG_FREE_UNKN)
 {
    if (num != -1)
    {
-       if(info_ptr->unknown_chunks)
+       if (info_ptr->unknown_chunks)
        {
           png_free(png_ptr, info_ptr->unknown_chunks[num].data);
           info_ptr->unknown_chunks[num].data = NULL;
@@ -508,7 +509,7 @@ if (mask & PNG_FREE_UNKN)
    {
        int i;
 
-       if(info_ptr->unknown_chunks_num)
+       if (info_ptr->unknown_chunks_num)
        {
          for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
             png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
@@ -562,7 +563,7 @@ if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
 if (mask & PNG_FREE_ROWS)
 #endif
 {
-    if(info_ptr->row_pointers)
+    if (info_ptr->row_pointers)
     {
        int row;
        for (row = 0; row < (int)info_ptr->height; row++)
@@ -578,7 +579,7 @@ if (mask & PNG_FREE_ROWS)
 #endif
 
 #ifdef PNG_FREE_ME_SUPPORTED
-   if(num == -1)
+   if (num == -1)
      info_ptr->free_me &= ~mask;
    else
      info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
@@ -601,7 +602,7 @@ png_info_destroy(png_structp png_ptr, png_infop info_ptr)
    {
        png_free(png_ptr, png_ptr->chunk_list);
        png_ptr->chunk_list=NULL;
-       png_ptr->num_chunk_list=0;
+       png_ptr->num_chunk_list = 0;
    }
 #endif
 
@@ -616,7 +617,7 @@ png_info_destroy(png_structp png_ptr, png_infop info_ptr)
 png_voidp PNGAPI
 png_get_io_ptr(png_structp png_ptr)
 {
-   if(png_ptr == NULL) return (NULL);
+   if (png_ptr == NULL) return (NULL);
    return (png_ptr->io_ptr);
 }
 
@@ -632,7 +633,7 @@ void PNGAPI
 png_init_io(png_structp png_ptr, png_FILE_p fp)
 {
    png_debug(1, "in png_init_io\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->io_ptr = (png_voidp)fp;
 }
 #endif
@@ -648,7 +649,7 @@ png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
         {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
          "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
 
-   if(png_ptr == NULL) return (NULL);
+   if (png_ptr == NULL) return (NULL);
    if (png_ptr->time_buffer == NULL)
    {
       png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
@@ -669,7 +670,7 @@ png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
 #ifdef USE_FAR_KEYWORD
    {
       char near_time_buf[29];
-      png_snprintf6(near_time_buf,29,"%d %s %d %02d:%02d:%02d +0000",
+      png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000",
           ptime->day % 32, short_months[(ptime->month - 1) % 12],
           ptime->year, ptime->hour % 24, ptime->minute % 60,
           ptime->second % 61);
@@ -677,7 +678,7 @@ png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
           29*png_sizeof(char));
    }
 #else
-   png_snprintf6(png_ptr->time_buffer,29,"%d %s %d %02d:%02d:%02d +0000",
+   png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000",
        ptime->day % 32, short_months[(ptime->month - 1) % 12],
        ptime->year, ptime->hour % 24, ptime->minute % 60,
        ptime->second % 61);
@@ -693,7 +694,7 @@ png_charp PNGAPI
 png_get_copyright(png_structp png_ptr)
 {
    png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
-   return ((png_charp) "\n libpng version 1.2.29 - May 8, 2008\n\
+   return ((png_charp) "\n libpng version 1.2.33 - October 31, 2008\n\
    Copyright (c) 1998-2008 Glenn Randers-Pehrson\n\
    Copyright (c) 1996-1997 Andreas Dilger\n\
    Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
@@ -743,12 +744,12 @@ png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
    /* check chunk_name and return "keep" value if it's on the list, else 0 */
    int i;
    png_bytep p;
-   if(png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
+   if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
       return 0;
-   p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5;
-   for (i = png_ptr->num_chunk_list; i; i--, p-=5)
+   p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5;
+   for (i = png_ptr->num_chunk_list; i; i--, p -= 5)
       if (!png_memcmp(chunk_name, p, 4))
-        return ((int)*(p+4));
+        return ((int)*(p + 4));
    return 0;
 }
 #endif
diff --git a/third_party/libpng/png.h b/third_party/libpng/png.h
index 2e194b7..7faa021 100644
--- a/third_party/libpng/png.h
+++ b/third_party/libpng/png.h
@@ -1,6 +1,6 @@
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.2.29 - May 8, 2008
+ * libpng version 1.2.33 - October 31, 2008
  * Copyright (c) 1998-2008 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.)
@@ -8,7 +8,7 @@
  * Authors and maintainers:
  *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *  libpng versions 0.97, January 1998, through 1.2.29 - May 8, 2008: Glenn
+ *  libpng versions 0.97, January 1998, through 1.2.33 - October 31, 2008: Glenn
  *  See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -192,6 +192,26 @@
  *    1.2.29rc01              13    10229  12.so.0.29[.0]
  *    1.0.35                  10    10035  10.so.0.35[.0]
  *    1.2.29                  13    10229  12.so.0.29[.0]
+ *    1.0.37                  10    10037  10.so.0.37[.0]
+ *    1.2.30beta01-04         13    10230  12.so.0.30[.0]
+ *    1.0.38rc01-08           10    10038  10.so.0.38[.0]
+ *    1.2.30rc01-08           13    10230  12.so.0.30[.0]
+ *    1.0.38                  10    10038  10.so.0.38[.0]
+ *    1.2.30                  13    10230  12.so.0.30[.0]
+ *    1.0.39rc01-03           10    10039  10.so.0.39[.0]
+ *    1.2.31rc01-03           13    10231  12.so.0.31[.0]
+ *    1.0.39                  10    10039  10.so.0.39[.0]
+ *    1.2.31                  13    10231  12.so.0.31[.0]
+ *    1.2.32beta01-02         13    10232  12.so.0.32[.0]
+ *    1.0.40rc01              10    10040  10.so.0.40[.0]
+ *    1.2.32rc01              13    10232  12.so.0.32[.0]
+ *    1.0.40                  10    10040  10.so.0.40[.0]
+ *    1.2.32                  13    10232  12.so.0.32[.0]
+ *    1.2.33beta01-02         13    10233  12.so.0.33[.0]
+ *    1.2.33rc01-02           13    10233  12.so.0.33[.0]
+ *    1.0.41rc01              10    10041  10.so.0.41[.0]
+ *    1.2.33                  13    10233  12.so.0.33[.0]
+ *    1.0.41                  10    10041  10.so.0.41[.0]
  *
  *    Henceforth the source version will match the shared-library major
  *    and minor numbers; the shared-library major version number will be
@@ -221,7 +241,7 @@
  * If you modify libpng you may insert additional notices immediately following
  * this sentence.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.2.29, May 8, 2008, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.2.33, October 31, 2008, are
  * Copyright (c) 2004, 2006-2008 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:
@@ -333,13 +353,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    May 8, 2008
+ *    October 31, 2008
  *
  *    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 1.2.29 are Y2K compliant.  It is my belief that earlier
+ *    upward through 1.2.33 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
@@ -395,9 +415,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.2.29"
+#define PNG_LIBPNG_VER_STRING "1.2.33"
 #define PNG_HEADER_VERSION_STRING \
-   " libpng version 1.2.29 - May 8, 2008\n"
+   " libpng version 1.2.33 - October 31, 2008\n"
 
 #define PNG_LIBPNG_VER_SONUM   0
 #define PNG_LIBPNG_VER_DLLNUM  13
@@ -405,7 +425,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   2
-#define PNG_LIBPNG_VER_RELEASE 29
+#define PNG_LIBPNG_VER_RELEASE 33
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
 
@@ -433,7 +453,7 @@
  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release */
-#define PNG_LIBPNG_VER 10229 /* 1.2.29 */
+#define PNG_LIBPNG_VER 10233 /* 1.2.33 */
 
 #ifndef PNG_VERSION_INFO_ONLY
 /* include the compression library's header */
@@ -1204,7 +1224,7 @@ struct png_struct_def
    png_uint_32 row_number;    /* current row in interlace pass */
    png_bytep prev_row;        /* buffer to save previous (unfiltered) row */
    png_bytep row_buf;         /* buffer to save current (unfiltered) row */
-#ifndef PNG_NO_WRITE_FILTERING
+#ifndef PNG_NO_WRITE_FILTER
    png_bytep sub_row;         /* buffer to save "sub" row when filtering */
    png_bytep up_row;          /* buffer to save "up" row when filtering */
    png_bytep avg_row;         /* buffer to save "avg" row when filtering */
@@ -1444,13 +1464,17 @@ struct png_struct_def
 
 /* New members added in libpng-1.2.26 */
   png_uint_32 old_big_row_buf_size, old_prev_row_size;
+
+/* New member added in libpng-1.2.30 */
+  png_charp chunkdata;  /* buffer for reading chunk data */
+
 };
 
 
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef png_structp version_1_2_29;
+typedef png_structp version_1_2_33;
 
 typedef png_struct FAR * FAR * png_structpp;
 
@@ -2645,6 +2669,7 @@ extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
    png_ptr));
 #endif
 
+
 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
 
 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
@@ -3026,8 +3051,8 @@ PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
 /* 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)
-PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
-   int comp_type, png_charp chunkdata, png_size_t chunklength,
+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));
 #endif
 
@@ -3556,6 +3581,9 @@ png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
 #endif /* PNG_pHYs_SUPPORTED */
 #endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
 
+/* Read the chunk header (length + type name) */
+PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
+
 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
 
 #endif /* PNG_INTERNAL */
diff --git a/third_party/libpng/pngconf.h b/third_party/libpng/pngconf.h
index d1e2995..e9423be 100644
--- a/third_party/libpng/pngconf.h
+++ b/third_party/libpng/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.2.29 - May 8, 2008
+ * libpng version 1.2.33 - October 31, 2008
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -1123,10 +1123,10 @@ typedef unsigned char png_byte;
    change (I'm not sure if you will or not, so I thought I'd be safe) */
 #ifdef PNG_SIZE_T
    typedef PNG_SIZE_T png_size_t;
-#  define png_sizeof(x) png_convert_size(sizeof (x))
+#  define png_sizeof(x) png_convert_size(sizeof(x))
 #else
    typedef size_t png_size_t;
-#  define png_sizeof(x) sizeof (x)
+#  define png_sizeof(x) sizeof(x)
 #endif
 
 /* The following is needed for medium model support.  It cannot be in the
diff --git a/third_party/libpng/pngerror.c b/third_party/libpng/pngerror.c
index b364fc0..cd2bdb8 100644
--- a/third_party/libpng/pngerror.c
+++ b/third_party/libpng/pngerror.c
@@ -1,9 +1,9 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.2.22 [October 13, 2007]
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2007 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2008 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.)
  *
@@ -15,8 +15,8 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
 static void /* PRIVATE */
 png_default_error PNGARG((png_structp png_ptr,
   png_const_charp error_message));
@@ -44,28 +44,29 @@ png_error(png_structp png_ptr, png_const_charp error_message)
      {
        if (*error_message == '#')
        {
+         /* Strip "#nnnn " from beginning of error message. */
            int offset;
-           for (offset=1; offset<15; offset++)
-              if (*(error_message+offset) == ' ')
+           for (offset = 1; offset<15; offset++)
+              if (error_message[offset] == ' ')
                   break;
            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
            {
               int i;
-              for (i=0; i<offset-1; i++)
-                 msg[i]=error_message[i+1];
-              msg[i]='\0';
-              error_message=msg;
+              for (i = 0; i < offset - 1; i++)
+                 msg[i] = error_message[i + 1];
+              msg[i - 1] = '\0';
+              error_message = msg;
            }
            else
-              error_message+=offset;
+              error_message += offset;
        }
        else
        {
            if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
            {
-              msg[0]='0';
-              msg[1]='\0';
-              error_message=msg;
+              msg[0] = '0';
+              msg[1] = '\0';
+              error_message = msg;
            }
        }
      }
@@ -110,16 +111,16 @@ png_warning(png_structp png_ptr, png_const_charp warning_message)
      {
        if (*warning_message == '#')
        {
-           for (offset=1; offset<15; offset++)
-              if (*(warning_message+offset) == ' ')
+           for (offset = 1; offset < 15; offset++)
+              if (warning_message[offset] == ' ')
                   break;
        }
      }
      if (png_ptr != NULL && png_ptr->warning_fn != NULL)
-        (*(png_ptr->warning_fn))(png_ptr, warning_message+offset);
+        (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
    }
    else
-      png_default_warning(png_ptr, warning_message+offset);
+      png_default_warning(png_ptr, warning_message + offset);
 }
 #endif /* PNG_NO_WARNINGS */
 
@@ -167,8 +168,8 @@ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
    {
       buffer[iout++] = ':';
       buffer[iout++] = ' ';
-      png_memcpy(buffer+iout, error_message, PNG_MAX_ERROR_TEXT);
-      buffer[iout+PNG_MAX_ERROR_TEXT-1] = '\0';
+      png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
+      buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
    }
 }
 
@@ -216,22 +217,23 @@ png_default_error(png_structp png_ptr, png_const_charp error_message)
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
    if (*error_message == '#')
    {
+     /* Strip "#nnnn " from beginning of warning message. */
      int offset;
      char error_number[16];
-     for (offset=0; offset<15; offset++)
+     for (offset = 0; offset<15; offset++)
      {
-         error_number[offset] = *(error_message+offset+1);
-         if (*(error_message+offset) == ' ')
+         error_number[offset] = error_message[offset + 1];
+         if (error_message[offset] == ' ')
              break;
      }
-     if((offset > 1) && (offset < 15))
+     if ((offset > 1) && (offset < 15))
      {
-       error_number[offset-1]='\0';
+       error_number[offset - 1] = '\0';
        fprintf(stderr, "libpng error no. %s: %s\n", error_number,
-          error_message+offset);
+          error_message + offset + 1);
      }
      else
-       fprintf(stderr, "libpng error: %s, offset=%d\n", error_message,offset);
+       fprintf(stderr, "libpng error: %s, offset=%d\n", error_message, offset);
    }
    else
 #endif
@@ -274,17 +276,17 @@ png_default_warning(png_structp png_ptr, png_const_charp warning_message)
    {
      int offset;
      char warning_number[16];
-     for (offset=0; offset<15; offset++)
+     for (offset = 0; offset < 15; offset++)
      {
-        warning_number[offset]=*(warning_message+offset+1);
-        if (*(warning_message+offset) == ' ')
+        warning_number[offset] = warning_message[offset + 1];
+        if (warning_message[offset] == ' ')
             break;
      }
-     if((offset > 1) && (offset < 15))
+     if ((offset > 1) && (offset < 15))
      {
-       warning_number[offset-1]='\0';
+       warning_number[offset + 1] = '\0';
        fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
-          warning_message+offset);
+          warning_message + offset);
      }
      else
        fprintf(stderr, "libpng warning: %s\n", warning_message);
@@ -333,7 +335,7 @@ png_get_error_ptr(png_structp png_ptr)
 void PNGAPI
 png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
 {
-   if(png_ptr != NULL)
+   if (png_ptr != NULL)
    {
      png_ptr->flags &=
        ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
diff --git a/third_party/libpng/pngget.c b/third_party/libpng/pngget.c
index a0e90bb..4e897c6 100644
--- a/third_party/libpng/pngget.c
+++ b/third_party/libpng/pngget.c
@@ -1,16 +1,15 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.2.15 January 5, 2007
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2007 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2008 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.)
  */
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
 png_uint_32 PNGAPI
@@ -122,7 +121,7 @@ png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
    if (info_ptr->valid & PNG_INFO_pHYs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_pixels_per_meter");
-      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
+      if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
           return (0);
       else return (info_ptr->x_pixels_per_unit);
    }
@@ -140,7 +139,7 @@ png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
    if (info_ptr->valid & PNG_INFO_pHYs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_pixels_per_meter");
-      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
+      if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
           return (0);
       else return (info_ptr->y_pixels_per_unit);
    }
@@ -158,7 +157,7 @@ png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
    if (info_ptr->valid & PNG_INFO_pHYs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_pixels_per_meter");
-      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER ||
+      if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER ||
          info_ptr->x_pixels_per_unit != info_ptr->y_pixels_per_unit)
           return (0);
       else return (info_ptr->x_pixels_per_unit);
@@ -199,7 +198,7 @@ png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr)
    if (info_ptr->valid & PNG_INFO_oFFs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
-      if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
+      if (info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
           return (0);
       else return (info_ptr->x_offset);
    }
@@ -217,7 +216,7 @@ png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr)
    if (info_ptr->valid & PNG_INFO_oFFs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
-      if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
+      if (info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
           return (0);
       else return (info_ptr->y_offset);
    }
@@ -235,7 +234,7 @@ png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr)
    if (info_ptr->valid & PNG_INFO_oFFs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
-      if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
+      if (info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
           return (0);
       else return (info_ptr->x_offset);
    }
@@ -253,7 +252,7 @@ png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr)
    if (info_ptr->valid & PNG_INFO_oFFs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
-      if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
+      if (info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
           return (0);
       else return (info_ptr->y_offset);
    }
@@ -323,7 +322,7 @@ png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
       {
          *unit_type = (int)info_ptr->phys_unit_type;
          retval |= PNG_INFO_pHYs;
-         if(*unit_type == 1)
+         if (*unit_type == 1)
          {
             if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
             if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
@@ -784,10 +783,10 @@ png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
              *trans_values = &(info_ptr->trans_values);
              retval |= PNG_INFO_tRNS;
           }
-          if(trans != NULL)
+          if (trans != NULL)
              *trans = NULL;
       }
-      if(num_trans != NULL)
+      if (num_trans != NULL)
       {
          *num_trans = info_ptr->num_trans;
          retval |= PNG_INFO_tRNS;
diff --git a/third_party/libpng/pngmem.c b/third_party/libpng/pngmem.c
index 13cc60c..e28476f 100644
--- a/third_party/libpng/pngmem.c
+++ b/third_party/libpng/pngmem.c
@@ -1,7 +1,7 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * Last changed in libpng 1.2.27 [April 29, 2008]
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -16,7 +16,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
 /* Borland DOS special memory handler */
@@ -48,7 +47,7 @@ png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
      return (png_get_copyright(NULL));
 
 #ifdef PNG_USER_MEM_SUPPORTED
-   if(malloc_fn != NULL)
+   if (malloc_fn != NULL)
    {
       png_struct dummy_struct;
       png_structp png_ptr = &dummy_struct;
@@ -80,7 +79,7 @@ png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
    if (struct_ptr != NULL)
    {
 #ifdef PNG_USER_MEM_SUPPORTED
-      if(free_fn != NULL)
+      if (free_fn != NULL)
       {
          png_struct dummy_struct;
          png_structp png_ptr = &dummy_struct;
@@ -122,7 +121,7 @@ png_malloc(png_structp png_ptr, png_uint_32 size)
       return (NULL);
 
 #ifdef PNG_USER_MEM_SUPPORTED
-   if(png_ptr->malloc_fn != NULL)
+   if (png_ptr->malloc_fn != NULL)
        ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
    else
        ret = (png_malloc_default(png_ptr, size));
@@ -171,7 +170,7 @@ png_malloc_default(png_structp png_ptr, png_uint_32 size)
                ret = NULL;
             }
 
-            if(png_ptr->zlib_window_bits > 14)
+            if (png_ptr->zlib_window_bits > 14)
                num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
             else
                num_blocks = 1;
@@ -210,7 +209,7 @@ png_malloc_default(png_structp png_ptr, png_uint_32 size)
 
             png_ptr->offset_table = table;
             png_ptr->offset_table_ptr = farmalloc(num_blocks *
-               png_sizeof (png_bytep));
+               png_sizeof(png_bytep));
 
             if (png_ptr->offset_table_ptr == NULL)
             {
@@ -273,6 +272,7 @@ png_malloc_default(png_structp png_ptr, png_uint_32 size)
 /* free a pointer allocated by png_malloc().  In the default
    configuration, png_ptr is not used, but is passed in case it
    is needed.  If ptr is NULL, return without taking any action. */
+
 void PNGAPI
 png_free(png_structp png_ptr, png_voidp ptr)
 {
@@ -293,7 +293,7 @@ png_free_default(png_structp png_ptr, png_voidp ptr)
 {
 #endif /* PNG_USER_MEM_SUPPORTED */
 
-   if(png_ptr == NULL || ptr == NULL) return;
+   if (png_ptr == NULL || ptr == NULL) return;
 
    if (png_ptr->offset_table != NULL)
    {
@@ -353,7 +353,7 @@ png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
       return (NULL);
 
 #ifdef PNG_USER_MEM_SUPPORTED
-   if(malloc_fn != NULL)
+   if (malloc_fn != NULL)
    {
       png_struct dummy_struct;
       png_structp png_ptr = &dummy_struct;
@@ -369,7 +369,7 @@ png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
    struct_ptr = (png_voidp)farmalloc(size);
 #else
 # if defined(_MSC_VER) && defined(MAXSEG_64K)
-   struct_ptr = (png_voidp)halloc(size,1);
+   struct_ptr = (png_voidp)halloc(size, 1);
 # else
    struct_ptr = (png_voidp)malloc(size);
 # endif
@@ -398,7 +398,7 @@ png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
    if (struct_ptr != NULL)
    {
 #ifdef PNG_USER_MEM_SUPPORTED
-      if(free_fn != NULL)
+      if (free_fn != NULL)
       {
          png_struct dummy_struct;
          png_structp png_ptr = &dummy_struct;
@@ -434,7 +434,7 @@ png_malloc(png_structp png_ptr, png_uint_32 size)
    if (png_ptr == NULL || size == 0)
       return (NULL);
 
-   if(png_ptr->malloc_fn != NULL)
+   if (png_ptr->malloc_fn != NULL)
        ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
    else
        ret = (png_malloc_default(png_ptr, size));
@@ -542,9 +542,9 @@ png_malloc_warn(png_structp png_ptr, png_uint_32 size)
 {
    png_voidp ptr;
    png_uint_32 save_flags;
-   if(png_ptr == NULL) return (NULL);
+   if (png_ptr == NULL) return (NULL);
 
-   save_flags=png_ptr->flags;
+   save_flags = png_ptr->flags;
    png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
    ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
    png_ptr->flags=save_flags;
@@ -560,7 +560,7 @@ png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
 
    size = (png_size_t)length;
    if ((png_uint_32)size != length)
-      png_error(png_ptr,"Overflow in png_memcpy_check.");
+      png_error(png_ptr, "Overflow in png_memcpy_check.");
 
    return(png_memcpy (s1, s2, size));
 }
@@ -573,7 +573,7 @@ png_memset_check (png_structp png_ptr, png_voidp s1, int value,
 
    size = (png_size_t)length;
    if ((png_uint_32)size != length)
-      png_error(png_ptr,"Overflow in png_memset_check.");
+      png_error(png_ptr, "Overflow in png_memset_check.");
 
    return (png_memset (s1, value, size));
 
@@ -587,10 +587,11 @@ void PNGAPI
 png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
   malloc_fn, png_free_ptr free_fn)
 {
-   if(png_ptr != NULL) {
-   png_ptr->mem_ptr = mem_ptr;
-   png_ptr->malloc_fn = malloc_fn;
-   png_ptr->free_fn = free_fn;
+   if (png_ptr != NULL)
+   {
+      png_ptr->mem_ptr = mem_ptr;
+      png_ptr->malloc_fn = malloc_fn;
+      png_ptr->free_fn = free_fn;
    }
 }
 
@@ -601,7 +602,7 @@ png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
 png_voidp PNGAPI
 png_get_mem_ptr(png_structp png_ptr)
 {
-   if(png_ptr == NULL) return (NULL);
+   if (png_ptr == NULL) return (NULL);
    return ((png_voidp)png_ptr->mem_ptr);
 }
 #endif /* PNG_USER_MEM_SUPPORTED */
diff --git a/third_party/libpng/pngpread.c b/third_party/libpng/pngpread.c
index aa7151c..b06fbad 100644
--- a/third_party/libpng/pngpread.c
+++ b/third_party/libpng/pngpread.c
@@ -1,7 +1,7 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.2.27 [April 29, 2008]
+ * Last changed in libpng 1.2.32 [September 18, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -10,7 +10,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 
 /* push model modes */
@@ -28,7 +27,7 @@ void PNGAPI
 png_process_data(png_structp png_ptr, png_infop info_ptr,
    png_bytep buffer, png_size_t buffer_size)
 {
-   if(png_ptr == NULL || info_ptr == NULL) return;
+   if (png_ptr == NULL || info_ptr == NULL) return;
    png_push_restore_buffer(png_ptr, buffer, buffer_size);
 
    while (png_ptr->buffer_size)
@@ -43,7 +42,7 @@ png_process_data(png_structp png_ptr, png_infop info_ptr,
 void /* PRIVATE */
 png_process_some_data(png_structp png_ptr, png_infop info_ptr)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    switch (png_ptr->process_mode)
    {
       case PNG_READ_SIG_MODE:
@@ -114,7 +113,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
 
    png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
       num_to_check);
-   png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes+num_to_check);
+   png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes + num_to_check);
 
    if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
    {
@@ -210,22 +209,23 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
       }
 
       png_push_fill_buffer(png_ptr, chunk_length, 4);
-      png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
+      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
       png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+      png_check_chunk_name(png_ptr, png_ptr->chunk_name);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
    }
 
    if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
-     if(png_ptr->mode & PNG_AFTER_IDAT)
+     if (png_ptr->mode & PNG_AFTER_IDAT)
         png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 
    if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
    {
+      if (png_ptr->push_length != 13)
+         png_error(png_ptr, "Invalid IHDR length");
       if (png_ptr->push_length + 4 > png_ptr->buffer_size)
       {
-         if (png_ptr->push_length != 13)
-            png_error(png_ptr, "Invalid IHDR length");
          png_push_save_buffer(png_ptr);
          return;
       }
@@ -565,7 +565,7 @@ png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
 {
    png_bytep ptr;
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    ptr = buffer;
    if (png_ptr->save_buffer_size)
    {
@@ -606,7 +606,7 @@ png_push_save_buffer(png_structp png_ptr)
    {
       if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
       {
-         png_size_t i,istop;
+         png_size_t i, istop;
          png_bytep sp;
          png_bytep dp;
 
@@ -675,7 +675,7 @@ png_push_read_IDAT(png_structp png_ptr)
       }
 
       png_push_fill_buffer(png_ptr, chunk_length, 4);
-      png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
+      png_ptr->push_length = png_get_uint_31(png_ptr, chunk_length);
       png_reset_crc(png_ptr);
       png_crc_read(png_ptr, png_ptr->chunk_name, 4);
       png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
@@ -698,7 +698,7 @@ png_push_read_IDAT(png_structp png_ptr)
       {
          save_size = (png_size_t)png_ptr->idat_size;
          /* check for overflow */
-         if((png_uint_32)save_size != png_ptr->idat_size)
+         if ((png_uint_32)save_size != png_ptr->idat_size)
             png_error(png_ptr, "save_size overflowed in pngpread");
       }
       else
@@ -720,7 +720,7 @@ png_push_read_IDAT(png_structp png_ptr)
       {
          save_size = (png_size_t)png_ptr->idat_size;
          /* check for overflow */
-         if((png_uint_32)save_size != png_ptr->idat_size)
+         if ((png_uint_32)save_size != png_ptr->idat_size)
             png_error(png_ptr, "save_size overflowed in pngpread");
       }
       else
@@ -760,7 +760,7 @@ png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
 
    png_ptr->zstream.next_in = buffer;
    png_ptr->zstream.avail_in = (uInt)buffer_length;
-   for(;;)
+   for (;;)
    {
       ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
       if (ret != Z_OK)
@@ -1020,37 +1020,32 @@ png_read_push_finish_row(png_structp png_ptr)
          png_ptr->rowbytes + 1);
       do
       {
-         int pass;
-         pass = png_ptr->pass;
-         pass++;
-         if ((pass == 1 && png_ptr->width < 5) ||
-             (pass == 3 && png_ptr->width < 3) ||
-             (pass == 5 && png_ptr->width < 2))
-           pass++;
-
-         if (pass > 7)
-            pass--;
-         png_ptr->pass = (png_byte) pass;
-         if (pass < 7)
-           {
-             png_ptr->iwidth = (png_ptr->width +
-                png_pass_inc[pass] - 1 -
-                png_pass_start[pass]) /
-                png_pass_inc[pass];
-
-             png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
-                png_ptr->iwidth) + 1;
-
-             if (png_ptr->transformations & PNG_INTERLACE)
-                break;
-
-             png_ptr->num_rows = (png_ptr->height +
-                png_pass_yinc[pass] - 1 -
-                png_pass_ystart[pass]) /
-                png_pass_yinc[pass];
-           }
-         else
-           break;
+         png_ptr->pass++;
+         if ((png_ptr->pass == 1 && png_ptr->width < 5) ||
+             (png_ptr->pass == 3 && png_ptr->width < 3) ||
+             (png_ptr->pass == 5 && png_ptr->width < 2))
+           png_ptr->pass++;
+
+         if (png_ptr->pass > 7)
+            png_ptr->pass--;
+         if (png_ptr->pass >= 7)
+            break;
+
+         png_ptr->iwidth = (png_ptr->width +
+            png_pass_inc[png_ptr->pass] - 1 -
+            png_pass_start[png_ptr->pass]) /
+            png_pass_inc[png_ptr->pass];
+
+         png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
+            png_ptr->iwidth) + 1;
+
+         if (png_ptr->transformations & PNG_INTERLACE)
+            break;
+
+         png_ptr->num_rows = (png_ptr->height +
+            png_pass_yinc[png_ptr->pass] - 1 -
+            png_pass_ystart[png_ptr->pass]) /
+            png_pass_yinc[png_ptr->pass];
 
       } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
    }
@@ -1079,7 +1074,7 @@ png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-         (png_uint_32)(length+1));
+      (png_uint_32)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
@@ -1177,7 +1172,7 @@ png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-       (png_uint_32)(length+1));
+      (png_uint_32)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
@@ -1268,8 +1263,8 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
             if (text == NULL)
             {
                text = (png_charp)png_malloc(png_ptr,
-                  (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
-                     + key_size + 1));
+                     (png_uint_32)(png_ptr->zbuf_size
+                     - png_ptr->zstream.avail_out + key_size + 1));
                png_memcpy(text + key_size, png_ptr->zbuf,
                   png_ptr->zbuf_size - png_ptr->zstream.avail_out);
                png_memcpy(text, key, key_size);
@@ -1283,8 +1278,8 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
 
                tmp = text;
                text = (png_charp)png_malloc(png_ptr, text_size +
-                  (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
-                   + 1));
+                  (png_uint_32)(png_ptr->zbuf_size 
+                  - png_ptr->zstream.avail_out + 1));
                png_memcpy(text, tmp, text_size);
                png_free(png_ptr, tmp);
                png_memcpy(text + text_size, png_ptr->zbuf,
@@ -1367,7 +1362,7 @@ png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
 #endif
 
    png_ptr->current_text = (png_charp)png_malloc(png_ptr,
-         (png_uint_32)(length+1));
+      (png_uint_32)(length + 1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
    png_ptr->current_text_size = (png_size_t)length;
@@ -1468,22 +1463,21 @@ void /* PRIVATE */
 png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
    length)
 {
-   png_uint_32 skip=0;
-   png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+   png_uint_32 skip = 0;
 
    if (!(png_ptr->chunk_name[0] & 0x20))
    {
 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
-     if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
-          PNG_HANDLE_CHUNK_ALWAYS
+      if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+         PNG_HANDLE_CHUNK_ALWAYS
 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
-          && png_ptr->read_user_chunk_fn == NULL
+         && png_ptr->read_user_chunk_fn == NULL
 #endif
-        )
+         )
 #endif
-        png_chunk_error(png_ptr, "unknown critical chunk");
+         png_chunk_error(png_ptr, "unknown critical chunk");
 
-     info_ptr = info_ptr; /* to quiet some compiler warnings */
+      info_ptr = info_ptr; /* to quiet some compiler warnings */
    }
 
 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
@@ -1500,18 +1494,20 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
       png_memcpy((png_charp)png_ptr->unknown_chunk.name,
                  (png_charp)png_ptr->chunk_name, 
                  png_sizeof(png_ptr->unknown_chunk.name));
-      png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]='\0';
+      png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name) - 1]
+        = '\0';
 
       png_ptr->unknown_chunk.size = (png_size_t)length;
       if (length == 0)
          png_ptr->unknown_chunk.data = NULL;
       else
       {
-         png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
+         png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr,
+       (png_uint_32)length);
          png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
       }
 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
-      if(png_ptr->read_user_chunk_fn != NULL)
+      if (png_ptr->read_user_chunk_fn != NULL)
       {
          /* callback to user unknown chunk handler */
          int ret;
@@ -1522,7 +1518,7 @@ png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
          if (ret == 0)
          {
             if (!(png_ptr->chunk_name[0] & 0x20))
-               if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+               if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
                     PNG_HANDLE_CHUNK_ALWAYS)
                   png_chunk_error(png_ptr, "unknown critical chunk");
             png_set_unknown_chunks(png_ptr, info_ptr,
@@ -1571,7 +1567,7 @@ png_progressive_combine_row (png_structp png_ptr,
    PNG_CONST int FARDATA png_pass_dsp_mask[7] =
       {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
 #endif
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (new_row != NULL)    /* new_row must == png_ptr->row_buf here. */
       png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
 }
@@ -1581,7 +1577,7 @@ png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
    png_progressive_end_ptr end_fn)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->info_fn = info_fn;
    png_ptr->row_fn = row_fn;
    png_ptr->end_fn = end_fn;
@@ -1592,7 +1588,7 @@ png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
 png_voidp PNGAPI
 png_get_progressive_ptr(png_structp png_ptr)
 {
-   if(png_ptr == NULL) return (NULL);
+   if (png_ptr == NULL) return (NULL);
    return png_ptr->io_ptr;
 }
 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
diff --git a/third_party/libpng/pngread.c b/third_party/libpng/pngread.c
index bd8bcd9..d7e424d 100644
--- a/third_party/libpng/pngread.c
+++ b/third_party/libpng/pngread.c
@@ -1,7 +1,7 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.2.25 [February 18, 2008]
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -13,7 +13,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED)
 
 /* Create a PNG structure for reading, and allocate any memory needed. */
@@ -35,6 +34,9 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 {
 #endif /* PNG_USER_MEM_SUPPORTED */
 
+#ifdef PNG_SETJMP_SUPPORTED
+   volatile
+#endif
    png_structp png_ptr;
 
 #ifdef PNG_SETJMP_SUPPORTED
@@ -69,7 +71,7 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #endif
    {
       png_free(png_ptr, png_ptr->zbuf);
-      png_ptr->zbuf=NULL;
+      png_ptr->zbuf = NULL;
 #ifdef PNG_USER_MEM_SUPPORTED
       png_destroy_struct_2((png_voidp)png_ptr,
          (png_free_ptr)free_fn, (png_voidp)mem_ptr);
@@ -79,7 +81,7 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
       return (NULL);
    }
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
 #endif
 #endif
 
@@ -89,12 +91,12 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
-   if(user_png_ver)
+   if (user_png_ver)
    {
-     i=0;
+     i = 0;
      do
      {
-       if(user_png_ver[i] != png_libpng_ver[i])
+       if (user_png_ver[i] != png_libpng_ver[i])
           png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
      } while (png_libpng_ver[i++]);
    }
@@ -128,7 +130,7 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
         png_warning(png_ptr, msg);
 #endif
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-        png_ptr->flags=0;
+        png_ptr->flags = 0;
 #endif
         png_error(png_ptr,
            "Incompatible libpng version in application and library");
@@ -164,7 +166,7 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
       PNG_ABORT();
-   png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
 #else
    if (setjmp(png_ptr->jmpbuf))
       PNG_ABORT();
@@ -190,13 +192,13 @@ png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
    png_size_t png_struct_size, png_size_t png_info_size)
 {
    /* We only come here via pre-1.0.12-compiled applications */
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
-   if(png_sizeof(png_struct) > png_struct_size ||
+   if (png_sizeof(png_struct) > png_struct_size ||
       png_sizeof(png_info) > png_info_size)
    {
       char msg[80];
-      png_ptr->warning_fn=NULL;
+      png_ptr->warning_fn = NULL;
       if (user_png_ver)
       {
         png_snprintf(msg, 80,
@@ -210,20 +212,20 @@ png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
       png_warning(png_ptr, msg);
    }
 #endif
-   if(png_sizeof(png_struct) > png_struct_size)
+   if (png_sizeof(png_struct) > png_struct_size)
      {
-       png_ptr->error_fn=NULL;
+       png_ptr->error_fn = NULL;
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-       png_ptr->flags=0;
+       png_ptr->flags = 0;
 #endif
        png_error(png_ptr,
        "The png struct allocated by the application for reading is too small.");
      }
-   if(png_sizeof(png_info) > png_info_size)
+   if (png_sizeof(png_info) > png_info_size)
      {
-       png_ptr->error_fn=NULL;
+       png_ptr->error_fn = NULL;
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
-       png_ptr->flags=0;
+       png_ptr->flags = 0;
 #endif
        png_error(png_ptr,
          "The info struct allocated by application for reading is too small.");
@@ -240,20 +242,20 @@ png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
    jmp_buf tmp_jmp;  /* to save current jump buffer */
 #endif
 
-   int i=0;
+   int i = 0;
 
    png_structp png_ptr=*ptr_ptr;
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 
    do
    {
-     if(user_png_ver[i] != png_libpng_ver[i])
+     if (user_png_ver[i] != png_libpng_ver[i])
      {
 #ifdef PNG_LEGACY_SUPPORTED
        png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
 #else
-       png_ptr->warning_fn=NULL;
+       png_ptr->warning_fn = NULL;
        png_warning(png_ptr,
         "Application uses deprecated png_read_init() and should be recompiled.");
        break;
@@ -265,22 +267,22 @@ png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* save jump buffer and error functions */
-   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 #endif
 
-   if(png_sizeof(png_struct) > png_struct_size)
-     {
-       png_destroy_struct(png_ptr);
-       *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
-       png_ptr = *ptr_ptr;
-     }
+   if (png_sizeof(png_struct) > png_struct_size)
+   {
+      png_destroy_struct(png_ptr);
+      *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
+      png_ptr = *ptr_ptr;
+   }
 
    /* reset all variables to 0 */
-   png_memset(png_ptr, 0, png_sizeof (png_struct));
+   png_memset(png_ptr, 0, png_sizeof(png_struct));
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* restore jump buffer */
-   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 
    /* added at libpng-1.2.6 */
@@ -324,7 +326,7 @@ png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 void PNGAPI
 png_read_info(png_structp png_ptr, png_infop info_ptr)
 {
-   if(png_ptr == NULL || info_ptr == NULL) return;
+   if (png_ptr == NULL || info_ptr == NULL) return;
    png_debug(1, "in png_read_info\n");
    /* If we haven't checked all of the PNG signature bytes, do so now. */
    if (png_ptr->sig_bytes < 8)
@@ -347,7 +349,7 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
          png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
    }
 
-   for(;;)
+   for (;;)
    {
 #ifdef PNG_USE_LOCAL_ARRAYS
       PNG_CONST PNG_IHDR;
@@ -406,38 +408,29 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
       PNG_CONST PNG_zTXt;
 #endif
 #endif /* PNG_USE_LOCAL_ARRAYS */
-      png_byte chunk_length[4];
-      png_uint_32 length;
-
-      png_read_data(png_ptr, chunk_length, 4);
-      length = png_get_uint_31(png_ptr,chunk_length);
-
-      png_reset_crc(png_ptr);
-      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-
-      png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
-         length);
+      png_uint_32 length = png_read_chunk_header(png_ptr);
+      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
 
       /* This should be a binary subdivision search or a hash for
        * matching the chunk name rather than a linear search.
        */
-      if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
-        if(png_ptr->mode & PNG_AFTER_IDAT)
+      if (!png_memcmp(chunk_name, png_IDAT, 4))
+        if (png_ptr->mode & PNG_AFTER_IDAT)
           png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
 
-      if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
+      if (!png_memcmp(chunk_name, png_IHDR, 4))
          png_handle_IHDR(png_ptr, info_ptr, length);
-      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+      else if (!png_memcmp(chunk_name, png_IEND, 4))
          png_handle_IEND(png_ptr, info_ptr, length);
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+      else if (png_handle_as_unknown(png_ptr, chunk_name))
       {
-         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+         if (!png_memcmp(chunk_name, png_IDAT, 4))
             png_ptr->mode |= PNG_HAVE_IDAT;
          png_handle_unknown(png_ptr, info_ptr, length);
-         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+         if (!png_memcmp(chunk_name, png_PLTE, 4))
             png_ptr->mode |= PNG_HAVE_PLTE;
-         else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+         else if (!png_memcmp(chunk_name, png_IDAT, 4))
          {
             if (!(png_ptr->mode & PNG_HAVE_IHDR))
                png_error(png_ptr, "Missing IHDR before IDAT");
@@ -448,9 +441,9 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
          }
       }
 #endif
-      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+      else if (!png_memcmp(chunk_name, png_PLTE, 4))
          png_handle_PLTE(png_ptr, info_ptr, length);
-      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      else if (!png_memcmp(chunk_name, png_IDAT, 4))
       {
          if (!(png_ptr->mode & PNG_HAVE_IHDR))
             png_error(png_ptr, "Missing IHDR before IDAT");
@@ -463,71 +456,71 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
          break;
       }
 #if defined(PNG_READ_bKGD_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
+      else if (!png_memcmp(chunk_name, png_bKGD, 4))
          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
+      else if (!png_memcmp(chunk_name, png_cHRM, 4))
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
+      else if (!png_memcmp(chunk_name, png_gAMA, 4))
          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
+      else if (!png_memcmp(chunk_name, png_hIST, 4))
          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
+      else if (!png_memcmp(chunk_name, png_oFFs, 4))
          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
+      else if (!png_memcmp(chunk_name, png_pCAL, 4))
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+      else if (!png_memcmp(chunk_name, png_sCAL, 4))
          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
+      else if (!png_memcmp(chunk_name, png_pHYs, 4))
          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
+      else if (!png_memcmp(chunk_name, png_sBIT, 4))
          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
+      else if (!png_memcmp(chunk_name, png_sRGB, 4))
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+      else if (!png_memcmp(chunk_name, png_iCCP, 4))
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+      else if (!png_memcmp(chunk_name, png_sPLT, 4))
          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
+      else if (!png_memcmp(chunk_name, png_tEXt, 4))
          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
+      else if (!png_memcmp(chunk_name, png_tIME, 4))
          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
+      else if (!png_memcmp(chunk_name, png_tRNS, 4))
          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+      else if (!png_memcmp(chunk_name, png_zTXt, 4))
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+      else if (!png_memcmp(chunk_name, png_iTXt, 4))
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
       else
@@ -541,7 +534,7 @@ void PNGAPI
 png_read_update_info(png_structp png_ptr, png_infop info_ptr)
 {
    png_debug(1, "in png_read_update_info\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
    else
@@ -560,7 +553,7 @@ void PNGAPI
 png_start_read_image(png_structp png_ptr)
 {
    png_debug(1, "in png_start_read_image\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
       png_read_start_row(png_ptr);
 }
@@ -573,11 +566,11 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 #ifdef PNG_USE_LOCAL_ARRAYS
    PNG_CONST PNG_IDAT;
    PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55,
-     0xff};
+      0xff};
    PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
 #endif
    int ret;
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
       png_ptr->row_number, png_ptr->pass);
    if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
@@ -703,15 +696,9 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
       {
          while (!png_ptr->idat_size)
          {
-            png_byte chunk_length[4];
-
             png_crc_finish(png_ptr, 0);
 
-            png_read_data(png_ptr, chunk_length, 4);
-            png_ptr->idat_size = png_get_uint_31(png_ptr,chunk_length);
-
-            png_reset_crc(png_ptr);
-            png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+            png_ptr->idat_size = png_read_chunk_header(png_ptr);
             if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
                png_error(png_ptr, "Not enough image data");
          }
@@ -747,7 +734,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
    png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
        png_ptr->row_info.width);
 
-   if(png_ptr->row_buf[0])
+   if (png_ptr->row_buf[0])
    png_read_filter_row(png_ptr, &(png_ptr->row_info),
       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
       (int)(png_ptr->row_buf[0]));
@@ -756,7 +743,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
       png_ptr->rowbytes + 1);
 
 #if defined(PNG_MNG_FEATURES_SUPPORTED)
-   if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */
@@ -836,7 +823,7 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
    png_bytepp dp;
 
    png_debug(1, "in png_read_rows\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    rp = row;
    dp = display_row;
    if (rp != NULL && dp != NULL)
@@ -847,14 +834,14 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
 
          png_read_row(png_ptr, rptr, dptr);
       }
-   else if(rp != NULL)
+   else if (rp != NULL)
       for (i = 0; i < num_rows; i++)
       {
          png_bytep rptr = *rp;
          png_read_row(png_ptr, rptr, png_bytep_NULL);
          rp++;
       }
-   else if(dp != NULL)
+   else if (dp != NULL)
       for (i = 0; i < num_rows; i++)
       {
          png_bytep dptr = *dp;
@@ -880,12 +867,12 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
 void PNGAPI
 png_read_image(png_structp png_ptr, png_bytepp image)
 {
-   png_uint_32 i,image_height;
+   png_uint_32 i, image_height;
    int pass, j;
    png_bytepp rp;
 
    png_debug(1, "in png_read_image\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
    pass = png_set_interlace_handling(png_ptr);
@@ -920,11 +907,8 @@ png_read_image(png_structp png_ptr, png_bytepp image)
 void PNGAPI
 png_read_end(png_structp png_ptr, png_infop info_ptr)
 {
-   png_byte chunk_length[4];
-   png_uint_32 length;
-
    png_debug(1, "in png_read_end\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
 
    do
@@ -986,33 +970,27 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
       PNG_CONST PNG_zTXt;
 #endif
 #endif /* PNG_USE_LOCAL_ARRAYS */
+      png_uint_32 length = png_read_chunk_header(png_ptr);
+      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
 
-      png_read_data(png_ptr, chunk_length, 4);
-      length = png_get_uint_31(png_ptr,chunk_length);
-
-      png_reset_crc(png_ptr);
-      png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-
-      png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
-
-      if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
+      if (!png_memcmp(chunk_name, png_IHDR, 4))
          png_handle_IHDR(png_ptr, info_ptr, length);
-      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+      else if (!png_memcmp(chunk_name, png_IEND, 4))
          png_handle_IEND(png_ptr, info_ptr, length);
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
-      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+      else if (png_handle_as_unknown(png_ptr, chunk_name))
       {
-         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+         if (!png_memcmp(chunk_name, png_IDAT, 4))
          {
             if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
                png_error(png_ptr, "Too many IDAT's found");
          }
          png_handle_unknown(png_ptr, info_ptr, length);
-         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+         if (!png_memcmp(chunk_name, png_PLTE, 4))
             png_ptr->mode |= PNG_HAVE_PLTE;
       }
 #endif
-      else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      else if (!png_memcmp(chunk_name, png_IDAT, 4))
       {
          /* Zero length IDATs are legal after the last IDAT has been
           * read, but not after other chunks have been read.
@@ -1021,74 +999,74 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
             png_error(png_ptr, "Too many IDAT's found");
          png_crc_finish(png_ptr, length);
       }
-      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+      else if (!png_memcmp(chunk_name, png_PLTE, 4))
          png_handle_PLTE(png_ptr, info_ptr, length);
 #if defined(PNG_READ_bKGD_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
+      else if (!png_memcmp(chunk_name, png_bKGD, 4))
          png_handle_bKGD(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_cHRM_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
+      else if (!png_memcmp(chunk_name, png_cHRM, 4))
          png_handle_cHRM(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_gAMA_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
+      else if (!png_memcmp(chunk_name, png_gAMA, 4))
          png_handle_gAMA(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
+      else if (!png_memcmp(chunk_name, png_hIST, 4))
          png_handle_hIST(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_oFFs_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
+      else if (!png_memcmp(chunk_name, png_oFFs, 4))
          png_handle_oFFs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pCAL_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
+      else if (!png_memcmp(chunk_name, png_pCAL, 4))
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sCAL_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+      else if (!png_memcmp(chunk_name, png_sCAL, 4))
          png_handle_sCAL(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_pHYs_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
+      else if (!png_memcmp(chunk_name, png_pHYs, 4))
          png_handle_pHYs(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sBIT_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
+      else if (!png_memcmp(chunk_name, png_sBIT, 4))
          png_handle_sBIT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sRGB_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
+      else if (!png_memcmp(chunk_name, png_sRGB, 4))
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iCCP_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+      else if (!png_memcmp(chunk_name, png_iCCP, 4))
          png_handle_iCCP(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_sPLT_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+      else if (!png_memcmp(chunk_name, png_sPLT, 4))
          png_handle_sPLT(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tEXt_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
+      else if (!png_memcmp(chunk_name, png_tEXt, 4))
          png_handle_tEXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tIME_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
+      else if (!png_memcmp(chunk_name, png_tIME, 4))
          png_handle_tIME(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
+      else if (!png_memcmp(chunk_name, png_tRNS, 4))
          png_handle_tRNS(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_zTXt_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+      else if (!png_memcmp(chunk_name, png_zTXt, 4))
          png_handle_zTXt(png_ptr, info_ptr, length);
 #endif
 #if defined(PNG_READ_iTXt_SUPPORTED)
-      else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+      else if (!png_memcmp(chunk_name, png_iTXt, 4))
          png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
       else
@@ -1111,9 +1089,7 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
 
    png_debug(1, "in png_destroy_read_struct\n");
    if (png_ptr_ptr != NULL)
-   {
       png_ptr = *png_ptr_ptr;
-   }
    if (png_ptr == NULL)
       return;
 
@@ -1159,13 +1135,16 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
       *end_info_ptr_ptr = NULL;
    }
 
+   if (png_ptr != NULL)
+   {
 #ifdef PNG_USER_MEM_SUPPORTED
-   png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
-       (png_voidp)mem_ptr);
+      png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
+          (png_voidp)mem_ptr);
 #else
-   png_destroy_struct((png_voidp)png_ptr);
+      png_destroy_struct((png_voidp)png_ptr);
 #endif
-   *png_ptr_ptr = NULL;
+      *png_ptr_ptr = NULL;
+   }
 }
 
 /* free all memory used by the read (old method) */
@@ -1192,6 +1171,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    png_free(png_ptr, png_ptr->zbuf);
    png_free(png_ptr, png_ptr->big_row_buf);
    png_free(png_ptr, png_ptr->prev_row);
+   png_free(png_ptr, png_ptr->chunkdata);
 #if defined(PNG_READ_DITHER_SUPPORTED)
    png_free(png_ptr, png_ptr->palette_lookup);
    png_free(png_ptr, png_ptr->dither_index);
@@ -1288,7 +1268,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
     * being used again.
     */
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 #endif
 
    error_fn = png_ptr->error_fn;
@@ -1298,7 +1278,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    free_fn = png_ptr->free_fn;
 #endif
 
-   png_memset(png_ptr, 0, png_sizeof (png_struct));
+   png_memset(png_ptr, 0, png_sizeof(png_struct));
 
    png_ptr->error_fn = error_fn;
    png_ptr->warning_fn = warning_fn;
@@ -1308,7 +1288,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 
 }
@@ -1316,7 +1296,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
 void PNGAPI
 png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->read_row_fn = read_row_fn;
 }
 
@@ -1330,7 +1310,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 {
    int row;
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
    /* invert the alpha channel from opacity to transparency
     */
@@ -1343,7 +1323,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
     */
    png_read_info(png_ptr, info_ptr);
    if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
-      png_error(png_ptr,"Image is too high to process with png_read_png()");
+      png_error(png_ptr, "Image is too high to process with png_read_png()");
 
    /* -------------- image transformations start here ------------------- */
 
@@ -1450,7 +1430,7 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 #ifdef PNG_FREE_ME_SUPPORTED
    png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
 #endif
-   if(info_ptr->row_pointers == NULL)
+   if (info_ptr->row_pointers == NULL)
    {
       info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
          info_ptr->height * png_sizeof(png_bytep));
diff --git a/third_party/libpng/pngrio.c b/third_party/libpng/pngrio.c
index 7d2522f..ff93cc6 100644
--- a/third_party/libpng/pngrio.c
+++ b/third_party/libpng/pngrio.c
@@ -1,9 +1,9 @@
 
 /* pngrio.c - functions for data input
  *
- * Last changed in libpng 1.2.13 November 13, 2006
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2006 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -17,7 +17,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED)
 
 /* Read the data from whatever input you are using.  The default routine
@@ -28,7 +27,7 @@
 void /* PRIVATE */
 png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
-   png_debug1(4,"reading %d bytes\n", (int)length);
+   png_debug1(4, "reading %d bytes\n", (int)length);
    if (png_ptr->read_data_fn != NULL)
       (*(png_ptr->read_data_fn))(png_ptr, data, length);
    else
@@ -46,7 +45,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
    png_size_t check;
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    /* fread() returns 0 on error, so it is OK to store this in a png_size_t
     * instead of an int, which is what fread() actually returns.
     */
@@ -77,7 +76,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
    png_byte *n_data;
    png_FILE_p io_ptr;
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    /* Check if data really is near. If so, use usual code. */
    n_data = (png_byte *)CVT_PTR_NOCHECK(data);
    io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
@@ -106,7 +105,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
          err = fread(buf, (png_size_t)1, read, io_ptr);
 #endif
          png_memcpy(data, buf, read); /* copy far buffer to near buffer */
-         if(err != read)
+         if (err != read)
             break;
          else
             check += err;
@@ -138,7 +137,7 @@ void PNGAPI
 png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
    png_rw_ptr read_data_fn)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->io_ptr = io_ptr;
 
 #if !defined(PNG_NO_STDIO)
diff --git a/third_party/libpng/pngrtran.c b/third_party/libpng/pngrtran.c
index 873b22c..fff66ec 100644
--- a/third_party/libpng/pngrtran.c
+++ b/third_party/libpng/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.2.27 [April 29, 2008]
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -15,7 +15,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED)
 
 /* Set the action on getting a CRC error for an ancillary or critical chunk. */
@@ -24,7 +23,7 @@ png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
 {
    png_debug(1, "in png_set_crc_action\n");
    /* Tell libpng how we react to CRC errors in critical chunks */
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    switch (crit_action)
    {
       case PNG_CRC_NO_CHANGE:                        /* leave setting as is */
@@ -39,7 +38,8 @@ png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
                            PNG_FLAG_CRC_CRITICAL_IGNORE;
          break;
       case PNG_CRC_WARN_DISCARD:    /* not a valid action for critical data */
-         png_warning(png_ptr, "Can't discard critical data on CRC error.");
+         png_warning(png_ptr,
+            "Can't discard critical data on CRC error.");
       case PNG_CRC_ERROR_QUIT:                                /* error/quit */
       case PNG_CRC_DEFAULT:
       default:
@@ -81,7 +81,7 @@ png_set_background(png_structp png_ptr,
    int need_expand, double background_gamma)
 {
    png_debug(1, "in png_set_background\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
    {
       png_warning(png_ptr, "Application must supply a known background gamma");
@@ -103,7 +103,7 @@ void PNGAPI
 png_set_strip_16(png_structp png_ptr)
 {
    png_debug(1, "in png_set_strip_16\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_16_TO_8;
 }
 #endif
@@ -113,7 +113,7 @@ void PNGAPI
 png_set_strip_alpha(png_structp png_ptr)
 {
    png_debug(1, "in png_set_strip_alpha\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;
 }
 #endif
@@ -143,7 +143,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
    int full_dither)
 {
    png_debug(1, "in png_set_dither\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_DITHER;
 
    if (!full_dither)
@@ -151,7 +151,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
       int i;
 
       png_ptr->dither_index = (png_bytep)png_malloc(png_ptr,
-         (png_uint_32)(num_palette * png_sizeof (png_byte)));
+         (png_uint_32)(num_palette * png_sizeof(png_byte)));
       for (i = 0; i < num_palette; i++)
          png_ptr->dither_index[i] = (png_byte)i;
    }
@@ -167,7 +167,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
 
          /* initialize an array to sort colors */
          png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
-            (png_uint_32)(num_palette * png_sizeof (png_byte)));
+            (png_uint_32)(num_palette * png_sizeof(png_byte)));
 
          /* initialize the dither_sort array */
          for (i = 0; i < num_palette; i++)
@@ -274,7 +274,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
             }
          }
          png_free(png_ptr, png_ptr->dither_sort);
-         png_ptr->dither_sort=NULL;
+         png_ptr->dither_sort = NULL;
       }
       else
       {
@@ -292,13 +292,13 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
          png_dsortp t;
          png_dsortpp hash;
 
-         t=NULL;
+         t = NULL;
 
          /* initialize palette index arrays */
          png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
-            (png_uint_32)(num_palette * png_sizeof (png_byte)));
+            (png_uint_32)(num_palette * png_sizeof(png_byte)));
          png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
-            (png_uint_32)(num_palette * png_sizeof (png_byte)));
+            (png_uint_32)(num_palette * png_sizeof(png_byte)));
 
          /* initialize the sort array */
          for (i = 0; i < num_palette; i++)
@@ -308,10 +308,10 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
          }
 
          hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *
-            png_sizeof (png_dsortp)));
+            png_sizeof(png_dsortp)));
          for (i = 0; i < 769; i++)
             hash[i] = NULL;
-/*         png_memset(hash, 0, 769 * png_sizeof (png_dsortp)); */
+/*         png_memset(hash, 0, 769 * png_sizeof(png_dsortp)); */
 
          num_new_palette = num_palette;
 
@@ -436,8 +436,8 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
          png_free(png_ptr, hash);
          png_free(png_ptr, png_ptr->palette_to_index);
          png_free(png_ptr, png_ptr->index_to_palette);
-         png_ptr->palette_to_index=NULL;
-         png_ptr->index_to_palette=NULL;
+         png_ptr->palette_to_index = NULL;
+         png_ptr->index_to_palette = NULL;
       }
       num_palette = maximum_colors;
    }
@@ -459,10 +459,10 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
       png_size_t num_entries = ((png_size_t)1 << total_bits);
 
       png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr,
-         (png_uint_32)(num_entries * png_sizeof (png_byte)));
+         (png_uint_32)(num_entries * png_sizeof(png_byte)));
 
       png_memset(png_ptr->palette_lookup, 0, num_entries *
-         png_sizeof (png_byte));
+         png_sizeof(png_byte));
 
       distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
          png_sizeof(png_byte)));
@@ -527,7 +527,7 @@ void PNGAPI
 png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
 {
    png_debug(1, "in png_set_gamma\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
        (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
        (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
@@ -546,7 +546,7 @@ void PNGAPI
 png_set_expand(png_structp png_ptr)
 {
    png_debug(1, "in png_set_expand\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
 }
@@ -573,7 +573,7 @@ void PNGAPI
 png_set_palette_to_rgb(png_structp png_ptr)
 {
    png_debug(1, "in png_set_palette_to_rgb\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
 }
@@ -584,7 +584,7 @@ void PNGAPI
 png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
 {
    png_debug(1, "in png_set_expand_gray_1_2_4_to_8\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_EXPAND;
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
 }
@@ -597,7 +597,7 @@ void PNGAPI
 png_set_gray_1_2_4_to_8(png_structp png_ptr)
 {
    png_debug(1, "in png_set_gray_1_2_4_to_8\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
 }
 #endif
@@ -635,7 +635,7 @@ png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
 {
       int red_fixed = (int)((float)red*100000.0 + 0.5);
       int green_fixed = (int)((float)green*100000.0 + 0.5);
-      if(png_ptr == NULL) return;
+      if (png_ptr == NULL) return;
       png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
 }
 #endif
@@ -645,7 +645,7 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
    png_fixed_point red, png_fixed_point green)
 {
    png_debug(1, "in png_set_rgb_to_gray\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    switch(error_action)
    {
       case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
@@ -659,18 +659,19 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
       png_ptr->transformations |= PNG_EXPAND;
 #else
    {
-      png_warning(png_ptr, "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
+      png_warning(png_ptr,
+        "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
       png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
    }
 #endif
    {
       png_uint_16 red_int, green_int;
-      if(red < 0 || green < 0)
+      if (red < 0 || green < 0)
       {
          red_int   =  6968; /* .212671 * 32768 + .5 */
          green_int = 23434; /* .715160 * 32768 + .5 */
       }
-      else if(red + green < 100000L)
+      else if (red + green < 100000L)
       {
         red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
         green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
@@ -683,7 +684,8 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
       }
       png_ptr->rgb_to_gray_red_coeff   = red_int;
       png_ptr->rgb_to_gray_green_coeff = green_int;
-      png_ptr->rgb_to_gray_blue_coeff  = (png_uint_16)(32768-red_int-green_int);
+      png_ptr->rgb_to_gray_blue_coeff  = 
+         (png_uint_16)(32768 - red_int - green_int);
    }
 }
 #endif
@@ -696,13 +698,13 @@ png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
    read_user_transform_fn)
 {
    png_debug(1, "in png_set_read_user_transform_fn\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
    png_ptr->transformations |= PNG_USER_TRANSFORM;
    png_ptr->read_user_transform_fn = read_user_transform_fn;
 #endif
 #ifdef PNG_LEGACY_SUPPORTED
-   if(read_user_transform_fn)
+   if (read_user_transform_fn)
       png_warning(png_ptr,
         "This version of libpng does not support user transforms");
 #endif
@@ -717,7 +719,7 @@ png_init_read_transformations(png_structp png_ptr)
 {
    png_debug(1, "in png_init_read_transformations\n");
 #if defined(PNG_USELESS_TESTS_SUPPORTED)
-   if(png_ptr != NULL)
+   if (png_ptr != NULL)
 #endif
   {
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \
@@ -818,7 +820,7 @@ png_init_read_transformations(png_structp png_ptr)
            {
            /* invert the alpha channel (in tRNS) unless the pixels are
               going to be expanded, in which case leave it for later */
-              int i,istop;
+              int i, istop;
               istop=(int)png_ptr->num_trans;
               for (i=0; i<istop; i++)
                  png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
@@ -839,7 +841,7 @@ png_init_read_transformations(png_structp png_ptr)
        && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)
          < PNG_GAMMA_THRESHOLD))
    {
-    int i,k;
+    int i, k;
     k=0;
     for (i=0; i<png_ptr->num_trans; i++)
     {
@@ -1110,7 +1112,7 @@ png_init_read_transformations(png_structp png_ptr)
  }
 #if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \
  && !defined(PNG_READ_BACKGROUND_SUPPORTED)
-   if(png_ptr)
+   if (png_ptr)
       return;
 #endif
 }
@@ -1239,11 +1241,11 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
 
 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
 defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
-   if(png_ptr->transformations & PNG_USER_TRANSFORM)
+   if (png_ptr->transformations & PNG_USER_TRANSFORM)
      {
-       if(info_ptr->bit_depth < png_ptr->user_transform_depth)
+       if (info_ptr->bit_depth < png_ptr->user_transform_depth)
          info_ptr->bit_depth = png_ptr->user_transform_depth;
-       if(info_ptr->channels < png_ptr->user_transform_channels)
+       if (info_ptr->channels < png_ptr->user_transform_channels)
          info_ptr->channels = png_ptr->user_transform_channels;
      }
 #endif
@@ -1251,10 +1253,10 @@ defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
    info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
       info_ptr->bit_depth);
 
-   info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth,info_ptr->width);
+   info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
 
 #if !defined(PNG_READ_EXPAND_SUPPORTED)
-   if(png_ptr)
+   if (png_ptr)
       return;
 #endif
 }
@@ -1273,7 +1275,7 @@ png_do_read_transformations(png_structp png_ptr)
       char msg[50];
 
       png_snprintf2(msg, 50,
-         "NULL row buffer for row %ld, pass %d", png_ptr->row_number,
+         "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number,
          png_ptr->pass);
       png_error(png_ptr, msg);
 #else
@@ -1324,13 +1326,13 @@ png_do_read_transformations(png_structp png_ptr)
    {
       int rgb_error =
          png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);
-      if(rgb_error)
+      if (rgb_error)
       {
          png_ptr->rgb_to_gray_status=1;
-         if((png_ptr->transformations & PNG_RGB_TO_GRAY) == 
+         if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == 
              PNG_RGB_TO_GRAY_WARN)
             png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
-         if((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+         if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
              PNG_RGB_TO_GRAY_ERR)
             png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
       }
@@ -1414,7 +1416,7 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
    {
       png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
          png_ptr->palette_lookup, png_ptr->dither_index);
-      if(png_ptr->row_info.rowbytes == (png_uint_32)0)
+      if (png_ptr->row_info.rowbytes == (png_uint_32)0)
          png_error(png_ptr, "png_do_dither returned rowbytes=0");
    }
 #endif
@@ -1476,7 +1478,7 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
    if (png_ptr->transformations & PNG_USER_TRANSFORM)
     {
-      if(png_ptr->read_user_transform_fn != NULL)
+      if (png_ptr->read_user_transform_fn != NULL)
         (*(png_ptr->read_user_transform_fn)) /* user read transform function */
           (png_ptr,                    /* png_ptr */
            &(png_ptr->row_info),       /* row_info:     */
@@ -1488,9 +1490,9 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
              /*  png_byte pixel_depth;       bits per pixel (depth*channels) */
            png_ptr->row_buf + 1);      /* start of pixel data for row */
 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
-      if(png_ptr->user_transform_depth)
+      if (png_ptr->user_transform_depth)
          png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
-      if(png_ptr->user_transform_channels)
+      if (png_ptr->user_transform_channels)
          png_ptr->row_info.channels = png_ptr->user_transform_channels;
 #endif
       png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
@@ -1967,7 +1969,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
 #endif
        row_info->color_type == PNG_COLOR_TYPE_GRAY)
    {
-      if(row_info->bit_depth == 8)
+      if (row_info->bit_depth == 8)
       {
          /* This changes the data from G to GX */
          if (flags & PNG_FLAG_FILLER_AFTER)
@@ -1999,7 +2001,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             row_info->rowbytes = row_width * 2;
          }
       }
-      else if(row_info->bit_depth == 16)
+      else if (row_info->bit_depth == 16)
       {
          /* This changes the data from GG to GGXX */
          if (flags & PNG_FLAG_FILLER_AFTER)
@@ -2039,7 +2041,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
    } /* COLOR_TYPE == GRAY */
    else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
    {
-      if(row_info->bit_depth == 8)
+      if (row_info->bit_depth == 8)
       {
          /* This changes the data from RGB to RGBX */
          if (flags & PNG_FLAG_FILLER_AFTER)
@@ -2075,7 +2077,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             row_info->rowbytes = row_width * 4;
          }
       }
-      else if(row_info->bit_depth == 16)
+      else if (row_info->bit_depth == 16)
       {
          /* This changes the data from RRGGBB to RRGGBBXX */
          if (flags & PNG_FLAG_FILLER_AFTER)
@@ -2202,7 +2204,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
       row_info->color_type |= PNG_COLOR_MASK_COLOR;
       row_info->pixel_depth = (png_byte)(row_info->channels *
          row_info->bit_depth);
-      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
    }
 }
 #endif
@@ -2210,8 +2212,10 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
 /* reduce RGB files to grayscale, with or without alpha
  * using the equation given in Poynton's ColorFAQ at
- * <http://www.inforamp.net/~poynton/>
- * Copyright (c) 1998-01-04 Charles Poynton poynton at inforamp.net
+ * <http://www.inforamp.net/~poynton/>  (THIS LINK IS DEAD June 2008)
+ * New link:
+ * <http://www.poynton.com/notes/colour_and_gamma/>
+ * Charles Poynton poynton at poynton.com
  *
  *     Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
  *
@@ -2262,14 +2266,14 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   png_byte red   = png_ptr->gamma_to_1[*(sp++)];
                   png_byte green = png_ptr->gamma_to_1[*(sp++)];
                   png_byte blue  = png_ptr->gamma_to_1[*(sp++)];
-                  if(red != green || red != blue)
+                  if (red != green || red != blue)
                   {
                      rgb_error |= 1;
                      *(dp++) = png_ptr->gamma_from_1[
-                       (rc*red+gc*green+bc*blue)>>15];
+                       (rc*red + gc*green + bc*blue)>>15];
                   }
                   else
-                     *(dp++) = *(sp-1);
+                     *(dp++) = *(sp - 1);
                }
             }
             else
@@ -2282,13 +2286,13 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   png_byte red   = *(sp++);
                   png_byte green = *(sp++);
                   png_byte blue  = *(sp++);
-                  if(red != green || red != blue)
+                  if (red != green || red != blue)
                   {
                      rgb_error |= 1;
-                     *(dp++) = (png_byte)((rc*red+gc*green+bc*blue)>>15);
+                     *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
                   }
                   else
-                     *(dp++) = *(sp-1);
+                     *(dp++) = *(sp - 1);
                }
             }
          }
@@ -2309,7 +2313,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
                   blue  = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
 
-                  if(red == green && red == blue)
+                  if (red == green && red == blue)
                      w = red;
                   else
                   {
@@ -2343,7 +2347,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
                   blue  = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
 
-                  if(red != green || red != blue)
+                  if (red != green || red != blue)
                      rgb_error |= 1;
                   gray16  = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
                   *(dp++) = (png_byte)((gray16>>8) & 0xff);
@@ -2366,7 +2370,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   png_byte red   = png_ptr->gamma_to_1[*(sp++)];
                   png_byte green = png_ptr->gamma_to_1[*(sp++)];
                   png_byte blue  = png_ptr->gamma_to_1[*(sp++)];
-                  if(red != green || red != blue)
+                  if (red != green || red != blue)
                      rgb_error |= 1;
                   *(dp++) =  png_ptr->gamma_from_1
                              [(rc*red + gc*green + bc*blue)>>15];
@@ -2383,7 +2387,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   png_byte red   = *(sp++);
                   png_byte green = *(sp++);
                   png_byte blue  = *(sp++);
-                  if(red != green || red != blue)
+                  if (red != green || red != blue)
                      rgb_error |= 1;
                   *(dp++) =  (png_byte)((rc*red + gc*green + bc*blue)>>15);
                   *(dp++) = *(sp++);  /* alpha */
@@ -2406,7 +2410,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
                   blue  = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
 
-                  if(red == green && red == blue)
+                  if (red == green && red == blue)
                      w = red;
                   else
                   {
@@ -2440,7 +2444,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   red   = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
                   green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
                   blue  = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
-                  if(red != green || red != blue)
+                  if (red != green || red != blue)
                      rgb_error |= 1;
                   gray16  = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
                   *(dp++) = (png_byte)((gray16>>8) & 0xff);
@@ -2455,7 +2459,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
       row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
       row_info->pixel_depth = (png_byte)(row_info->channels *
          row_info->bit_depth);
-      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
    }
    return rgb_error;
 }
@@ -3373,7 +3377,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
          row_info->channels--;
          row_info->pixel_depth = (png_byte)(row_info->channels *
             row_info->bit_depth);
-         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
       }
    }
 }
@@ -3832,7 +3836,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
                dp = row + (row_info->rowbytes << 1) - 1;
                for (i = 0; i < row_width; i++)
                {
-                  if (*(sp-1) == gray_high && *(sp) == gray_low) 
+                  if (*(sp - 1) == gray_high && *(sp) == gray_low) 
                   {
                      *dp-- = 0;
                      *dp-- = 0;
@@ -3911,7 +3915,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
          row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
          row_info->channels = 4;
          row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
-         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
       }
    }
 }
@@ -3964,7 +3968,7 @@ png_do_dither(png_row_infop row_info, png_bytep row,
          row_info->color_type = PNG_COLOR_TYPE_PALETTE;
          row_info->channels = 1;
          row_info->pixel_depth = row_info->bit_depth;
-         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
       }
       else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
          palette_lookup != NULL && row_info->bit_depth == 8)
@@ -3993,7 +3997,7 @@ png_do_dither(png_row_infop row_info, png_bytep row,
          row_info->color_type = PNG_COLOR_TYPE_PALETTE;
          row_info->channels = 1;
          row_info->pixel_depth = row_info->bit_depth;
-         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+         row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
       }
       else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
          dither_lookup && row_info->bit_depth == 8)
@@ -4062,7 +4066,7 @@ png_build_gamma_table(png_structp png_ptr)
         png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
            (png_uint_32)256);
 
-        if(png_ptr->screen_gamma > 0.000001)
+        if (png_ptr->screen_gamma > 0.000001)
            g = 1.0 / png_ptr->screen_gamma;
         else
            g = png_ptr->gamma;   /* probably doing rgb_to_gray */
@@ -4122,7 +4126,7 @@ png_build_gamma_table(png_structp png_ptr)
         g = 1.0;
 
      png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
-        (png_uint_32)(num * png_sizeof (png_uint_16p)));
+        (png_uint_32)(num * png_sizeof(png_uint_16p)));
 
      if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
      {
@@ -4132,7 +4136,7 @@ png_build_gamma_table(png_structp png_ptr)
         for (i = 0; i < num; i++)
         {
            png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
-              (png_uint_32)(256 * png_sizeof (png_uint_16)));
+              (png_uint_32)(256 * png_sizeof(png_uint_16)));
         }
 
         g = 1.0 / g;
@@ -4162,7 +4166,7 @@ png_build_gamma_table(png_structp png_ptr)
         for (i = 0; i < num; i++)
         {
            png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
-              (png_uint_32)(256 * png_sizeof (png_uint_16)));
+              (png_uint_32)(256 * png_sizeof(png_uint_16)));
 
            ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);
            for (j = 0; j < 256; j++)
@@ -4182,12 +4186,12 @@ png_build_gamma_table(png_structp png_ptr)
         g = 1.0 / (png_ptr->gamma);
 
         png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
-           (png_uint_32)(num * png_sizeof (png_uint_16p )));
+           (png_uint_32)(num * png_sizeof(png_uint_16p )));
 
         for (i = 0; i < num; i++)
         {
            png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,
-              (png_uint_32)(256 * png_sizeof (png_uint_16)));
+              (png_uint_32)(256 * png_sizeof(png_uint_16)));
 
            ig = (((png_uint_32)i *
               (png_uint_32)png_gamma_shift[shift]) >> 4);
@@ -4199,18 +4203,18 @@ png_build_gamma_table(png_structp png_ptr)
            }
         }
 
-        if(png_ptr->screen_gamma > 0.000001)
+        if (png_ptr->screen_gamma > 0.000001)
            g = 1.0 / png_ptr->screen_gamma;
         else
            g = png_ptr->gamma;   /* probably doing rgb_to_gray */
 
         png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
-           (png_uint_32)(num * png_sizeof (png_uint_16p)));
+           (png_uint_32)(num * png_sizeof(png_uint_16p)));
 
         for (i = 0; i < num; i++)
         {
            png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,
-              (png_uint_32)(256 * png_sizeof (png_uint_16)));
+              (png_uint_32)(256 * png_sizeof(png_uint_16)));
 
            ig = (((png_uint_32)i *
               (png_uint_32)png_gamma_shift[shift]) >> 4);
@@ -4275,11 +4279,11 @@ png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
 
          for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
          {
-            png_uint_32 s0   = (*(rp  ) << 8) | *(rp+1);
-            png_uint_32 s1   = (*(rp+2) << 8) | *(rp+3);
-            png_uint_32 s2   = (*(rp+4) << 8) | *(rp+5);
-            png_uint_32 red  = (png_uint_32)((s0+s1+65536L) & 0xffffL);
-            png_uint_32 blue = (png_uint_32)((s2+s1+65536L) & 0xffffL);
+            png_uint_32 s0   = (*(rp    ) << 8) | *(rp + 1);
+            png_uint_32 s1   = (*(rp + 2) << 8) | *(rp + 3);
+            png_uint_32 s2   = (*(rp + 4) << 8) | *(rp + 5);
+            png_uint_32 red  = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL);
+            png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL);
             *(rp  ) = (png_byte)((red >> 8) & 0xff);
             *(rp+1) = (png_byte)(red & 0xff);
             *(rp+4) = (png_byte)((blue >> 8) & 0xff);
diff --git a/third_party/libpng/pngrutil.c b/third_party/libpng/pngrutil.c
index 531cb05..07e294e 100644
--- a/third_party/libpng/pngrutil.c
+++ b/third_party/libpng/pngrutil.c
@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.2.27 [April 29, 2008]
+ * Last changed in libpng 1.2.33 [October 31, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -13,7 +13,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED)
 
 #if defined(_WIN32_WCE) && (_WIN32_WCE<0x500)
@@ -30,7 +29,7 @@ __inline double png_strtod(png_structp png_ptr, PNG_CONST char *nptr, char **end
    wchar_t *str, *end;
 
    len = MultiByteToWideChar(CP_ACP, 0, nptr, -1, NULL, 0);
-   str = (wchar_t *)png_malloc(png_ptr, len * sizeof(wchar_t));
+   str = (wchar_t *)png_malloc(png_ptr, len * png_sizeof(wchar_t));
    if ( NULL != str )
    {
       MultiByteToWideChar(CP_ACP, 0, nptr, -1, str, len);
@@ -49,7 +48,15 @@ __inline double png_strtod(png_structp png_ptr, PNG_CONST char *nptr, char **end
 png_uint_32 PNGAPI
 png_get_uint_31(png_structp png_ptr, png_bytep buf)
 {
+#ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
    png_uint_32 i = png_get_uint_32(buf);
+#else
+   /* Avoid an extra function call by inlining the result. */
+   png_uint_32 i = ((png_uint_32)(*buf) << 24) +
+      ((png_uint_32)(*(buf + 1)) << 16) +
+      ((png_uint_32)(*(buf + 2)) << 8) +
+      (png_uint_32)(*(buf + 3));
+#endif
    if (i > PNG_UINT_31_MAX)
      png_error(png_ptr, "PNG unsigned integer out of range.");
    return (i);
@@ -92,11 +99,40 @@ png_get_uint_16(png_bytep buf)
 }
 #endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */
 
+/* Read the chunk header (length + type name).
+ * Put the type name into png_ptr->chunk_name, and return the length.
+ */
+png_uint_32 /* PRIVATE */
+png_read_chunk_header(png_structp png_ptr)
+{
+   png_byte buf[8];
+   png_uint_32 length;
+
+   /* read the length and the chunk name */
+   png_read_data(png_ptr, buf, 8);
+   length = png_get_uint_31(png_ptr, buf);
+
+   /* put the chunk name into png_ptr->chunk_name */
+   png_memcpy(png_ptr->chunk_name, buf + 4, 4);
+
+   png_debug2(0, "Reading %s chunk, length = %lu\n",
+      png_ptr->chunk_name, length);
+
+   /* reset the crc and run it over the chunk name */
+   png_reset_crc(png_ptr);
+   png_calculate_crc(png_ptr, png_ptr->chunk_name, 4);
+
+   /* check to see if chunk name is valid */
+   png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+
+   return length;
+}
+
 /* Read data, and (optionally) run it through the CRC. */
 void /* PRIVATE */
 png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_read_data(png_ptr, buf, length);
    png_calculate_crc(png_ptr, buf, length);
 }
@@ -180,9 +216,9 @@ png_crc_error(png_structp png_ptr)
  * holding the original prefix part and an uncompressed version of the
  * trailing part (the malloc area passed in is freed).
  */
-png_charp /* PRIVATE */
+void /* PRIVATE */
 png_decompress_chunk(png_structp png_ptr, int comp_type,
-                              png_charp chunkdata, png_size_t chunklength,
+                              png_size_t chunklength,
                               png_size_t prefix_size, png_size_t *newlength)
 {
    static PNG_CONST char msg[] = "Error decoding compressed text";
@@ -192,7 +228,7 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
    if (comp_type == PNG_COMPRESSION_TYPE_BASE)
    {
       int ret = Z_OK;
-      png_ptr->zstream.next_in = (png_bytep)(chunkdata + prefix_size);
+      png_ptr->zstream.next_in = (png_bytep)(png_ptr->chunkdata + prefix_size);
       png_ptr->zstream.avail_in = (uInt)(chunklength - prefix_size);
       png_ptr->zstream.next_out = png_ptr->zbuf;
       png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
@@ -218,18 +254,20 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
                text = (png_charp)png_malloc_warn(png_ptr, text_size);
                if (text ==  NULL)
                  {
-                    png_free(png_ptr,chunkdata);
-                    png_error(png_ptr,"Not enough memory to decompress chunk");
+                    png_free(png_ptr, png_ptr->chunkdata);
+                    png_ptr->chunkdata = NULL;
+                    png_error(png_ptr, "Not enough memory to decompress chunk");
                  }
-               png_memcpy(text, chunkdata, prefix_size);
+               png_memcpy(text, png_ptr->chunkdata, prefix_size);
             }
 
             text[text_size - 1] = 0x00;
 
             /* Copy what we can of the error message into the text chunk */
-            text_size = (png_size_t)(chunklength - (text - chunkdata) - 1);
-            text_size = png_sizeof(msg) > text_size ? text_size :
-               png_sizeof(msg);
+            text_size = (png_size_t)(chunklength -
+              (text - png_ptr->chunkdata) - 1);
+            if (text_size > png_sizeof(msg))
+               text_size = png_sizeof(msg);
             png_memcpy(text + prefix_size, msg, text_size);
             break;
          }
@@ -241,13 +279,15 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
                    png_ptr->zbuf_size - png_ptr->zstream.avail_out;
                text = (png_charp)png_malloc_warn(png_ptr, text_size + 1);
                if (text ==  NULL)
-                 {
-                    png_free(png_ptr,chunkdata);
-                    png_error(png_ptr,"Not enough memory to decompress chunk.");
-                 }
+               {
+                  png_free(png_ptr, png_ptr->chunkdata);
+                  png_ptr->chunkdata = NULL;
+                  png_error(png_ptr,
+                    "Not enough memory to decompress chunk.");
+               }
                png_memcpy(text + prefix_size, png_ptr->zbuf,
                     text_size - prefix_size);
-               png_memcpy(text, chunkdata, prefix_size);
+               png_memcpy(text, png_ptr->chunkdata, prefix_size);
                *(text + text_size) = 0x00;
             }
             else
@@ -261,8 +301,10 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
                if (text == NULL)
                {
                   png_free(png_ptr, tmp);
-                  png_free(png_ptr, chunkdata);
-                  png_error(png_ptr,"Not enough memory to decompress chunk..");
+                  png_free(png_ptr, png_ptr->chunkdata);
+                  png_ptr->chunkdata = NULL;
+                  png_error(png_ptr,
+                    "Not enough memory to decompress chunk..");
                }
                png_memcpy(text, tmp, text_size);
                png_free(png_ptr, tmp);
@@ -302,16 +344,17 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
          png_warning(png_ptr,
             "Incomplete compressed datastream in chunk other than IDAT");
 #endif
-         text_size=prefix_size;
+         text_size = prefix_size;
          if (text ==  NULL)
          {
             text = (png_charp)png_malloc_warn(png_ptr, text_size+1);
             if (text == NULL)
               {
-                png_free(png_ptr, chunkdata);
-                png_error(png_ptr,"Not enough memory for text.");
+                png_free(png_ptr, png_ptr->chunkdata);
+                png_ptr->chunkdata = NULL;
+                png_error(png_ptr, "Not enough memory for text.");
               }
-            png_memcpy(text, chunkdata, prefix_size);
+            png_memcpy(text, png_ptr->chunkdata, prefix_size);
          }
          *(text + text_size) = 0x00;
       }
@@ -319,8 +362,8 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
       inflateReset(&png_ptr->zstream);
       png_ptr->zstream.avail_in = 0;
 
-      png_free(png_ptr, chunkdata);
-      chunkdata = text;
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = text;
       *newlength=text_size;
    }
    else /* if (comp_type != PNG_COMPRESSION_TYPE_BASE) */
@@ -328,18 +371,15 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
       char umsg[50];
 
-      png_snprintf(umsg, 50,
-         "Unknown zTXt compression type %d", comp_type);
+      png_snprintf(umsg, 50, "Unknown zTXt compression type %d", comp_type);
       png_warning(png_ptr, umsg);
 #else
       png_warning(png_ptr, "Unknown zTXt compression type");
 #endif
 
-      *(chunkdata + prefix_size) = 0x00;
-      *newlength=prefix_size;
+      *(png_ptr->chunkdata + prefix_size) = 0x00;
+      *newlength = prefix_size;
    }
-
-   return chunkdata;
 }
 #endif
 
@@ -406,10 +446,10 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    /* set up other useful info */
    png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth *
    png_ptr->channels);
-   png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->width);
-   png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth);
-   png_debug1(3,"channels = %d\n", png_ptr->channels);
-   png_debug1(3,"rowbytes = %lu\n", png_ptr->rowbytes);
+   png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
+   png_debug1(3, "bit_depth = %d\n", png_ptr->bit_depth);
+   png_debug1(3, "channels = %d\n", png_ptr->channels);
+   png_debug1(3, "rowbytes = %lu\n", png_ptr->rowbytes);
    png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
       color_type, interlace_type, compression_type, filter_type);
 }
@@ -571,7 +611,7 @@ png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
    png_crc_finish(png_ptr, length);
 
-   info_ptr =info_ptr; /* quiet compiler warnings about unused info_ptr */
+   info_ptr = info_ptr; /* quiet compiler warnings about unused info_ptr */
 }
 
 #if defined(PNG_READ_gAMA_SUPPORTED)
@@ -725,7 +765,7 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 void /* PRIVATE */
 png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   png_byte buf[4];
+   png_byte buf[32];
 #ifdef PNG_FLOATING_POINT_SUPPORTED
    float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
 #endif
@@ -766,62 +806,46 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       return;
    }
 
-   png_crc_read(png_ptr, buf, 4);
-   uint_x = png_get_uint_32(buf);
-
-   png_crc_read(png_ptr, buf, 4);
-   uint_y = png_get_uint_32(buf);
+   png_crc_read(png_ptr, buf, 32);
+   if (png_crc_finish(png_ptr, 0))
+      return;
 
+   uint_x = png_get_uint_32(buf);
+   uint_y = png_get_uint_32(buf + 4);
    if (uint_x > 80000L || uint_y > 80000L ||
       uint_x + uint_y > 100000L)
    {
       png_warning(png_ptr, "Invalid cHRM white point");
-      png_crc_finish(png_ptr, 24);
       return;
    }
    int_x_white = (png_fixed_point)uint_x;
    int_y_white = (png_fixed_point)uint_y;
 
-   png_crc_read(png_ptr, buf, 4);
-   uint_x = png_get_uint_32(buf);
-
-   png_crc_read(png_ptr, buf, 4);
-   uint_y = png_get_uint_32(buf);
-
+   uint_x = png_get_uint_32(buf + 8);
+   uint_y = png_get_uint_32(buf + 12);
    if (uint_x + uint_y > 100000L)
    {
       png_warning(png_ptr, "Invalid cHRM red point");
-      png_crc_finish(png_ptr, 16);
       return;
    }
    int_x_red = (png_fixed_point)uint_x;
    int_y_red = (png_fixed_point)uint_y;
 
-   png_crc_read(png_ptr, buf, 4);
-   uint_x = png_get_uint_32(buf);
-
-   png_crc_read(png_ptr, buf, 4);
-   uint_y = png_get_uint_32(buf);
-
+   uint_x = png_get_uint_32(buf + 16);
+   uint_y = png_get_uint_32(buf + 20);
    if (uint_x + uint_y > 100000L)
    {
       png_warning(png_ptr, "Invalid cHRM green point");
-      png_crc_finish(png_ptr, 8);
       return;
    }
    int_x_green = (png_fixed_point)uint_x;
    int_y_green = (png_fixed_point)uint_y;
 
-   png_crc_read(png_ptr, buf, 4);
-   uint_x = png_get_uint_32(buf);
-
-   png_crc_read(png_ptr, buf, 4);
-   uint_y = png_get_uint_32(buf);
-
+   uint_x = png_get_uint_32(buf + 24);
+   uint_y = png_get_uint_32(buf + 28);
    if (uint_x + uint_y > 100000L)
    {
       png_warning(png_ptr, "Invalid cHRM blue point");
-      png_crc_finish(png_ptr, 0);
       return;
    }
    int_x_blue = (png_fixed_point)uint_x;
@@ -854,19 +878,18 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
               "Ignoring incorrect cHRM value when sRGB is also present");
 #ifndef PNG_NO_CONSOLE_IO
 #ifdef PNG_FLOATING_POINT_SUPPORTED
-            fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n",
+            fprintf(stderr, "wx=%f, wy=%f, rx=%f, ry=%f\n",
                white_x, white_y, red_x, red_y);
-            fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n",
+            fprintf(stderr, "gx=%f, gy=%f, bx=%f, by=%f\n",
                green_x, green_y, blue_x, blue_y);
 #else
-            fprintf(stderr,"wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
+            fprintf(stderr, "wx=%ld, wy=%ld, rx=%ld, ry=%ld\n",
                int_x_white, int_y_white, int_x_red, int_y_red);
-            fprintf(stderr,"gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
+            fprintf(stderr, "gx=%ld, gy=%ld, bx=%ld, by=%ld\n",
                int_x_green, int_y_green, int_x_blue, int_y_blue);
 #endif
 #endif /* PNG_NO_CONSOLE_IO */
          }
-         png_crc_finish(png_ptr, 0);
          return;
       }
 #endif /* PNG_READ_sRGB_SUPPORTED */
@@ -880,8 +903,6 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       int_x_white, int_y_white, int_x_red, int_y_red, int_x_green,
       int_y_green, int_x_blue, int_y_blue);
 #endif
-   if (png_crc_finish(png_ptr, 0))
-      return;
 }
 #endif
 
@@ -949,10 +970,11 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
            "Ignoring incorrect gAMA value when sRGB is also present");
 #ifndef PNG_NO_CONSOLE_IO
 #  ifdef PNG_FIXED_POINT_SUPPORTED
-         fprintf(stderr,"incorrect gamma=(%d/100000)\n",(int)png_ptr->int_gamma);
+         fprintf(stderr, "incorrect gamma=(%d/100000)\n",
+            (int)png_ptr->int_gamma);
 #  else
 #    ifdef PNG_FLOATING_POINT_SUPPORTED
-         fprintf(stderr,"incorrect gamma=%f\n",png_ptr->gamma);
+         fprintf(stderr, "incorrect gamma=%f\n", png_ptr->gamma);
 #    endif
 #  endif
 #endif
@@ -987,7 +1009,6 @@ void /* PRIVATE */
 png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 /* Note: this does not properly handle chunks that are > 64K under DOS */
 {
-   png_charp chunkdata;
    png_byte compression_type;
    png_bytep pC;
    png_charp profile;
@@ -1025,28 +1046,31 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 #endif
 
-   chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
    slength = (png_size_t)length;
-   png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
 
    if (png_crc_finish(png_ptr, skip))
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
-   chunkdata[slength] = 0x00;
+   png_ptr->chunkdata[slength] = 0x00;
 
-   for (profile = chunkdata; *profile; profile++)
+   for (profile = png_ptr->chunkdata; *profile; profile++)
       /* empty loop to find end of name */ ;
 
    ++profile;
 
    /* there should be at least one zero (the compression type byte)
       following the separator, and we should be on it  */
-   if ( profile >= chunkdata + slength - 1)
+   if ( profile >= png_ptr->chunkdata + slength - 1)
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       png_warning(png_ptr, "Malformed iCCP chunk");
       return;
    }
@@ -1056,43 +1080,46 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (compression_type)
    {
       png_warning(png_ptr, "Ignoring nonzero compression type in iCCP chunk");
-      compression_type=0x00;  /* Reset it to zero (libpng-1.0.6 through 1.0.8
+      compression_type = 0x00;  /* Reset it to zero (libpng-1.0.6 through 1.0.8
                                  wrote nonzero) */
    }
 
-   prefix_length = profile - chunkdata;
-   chunkdata = png_decompress_chunk(png_ptr, compression_type, chunkdata,
-                                    slength, prefix_length, &data_length);
+   prefix_length = profile - png_ptr->chunkdata;
+   png_decompress_chunk(png_ptr, compression_type,
+     slength, prefix_length, &data_length);
 
    profile_length = data_length - prefix_length;
 
    if ( prefix_length > data_length || profile_length < 4)
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       png_warning(png_ptr, "Profile size field missing from iCCP chunk");
       return;
    }
 
    /* Check the profile_size recorded in the first 32 bits of the ICC profile */
-   pC = (png_bytep)(chunkdata+prefix_length);
-   profile_size = ((*(pC  ))<<24) |
-                  ((*(pC+1))<<16) |
-                  ((*(pC+2))<< 8) |
-                  ((*(pC+3))    );
+   pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
+   profile_size = ((*(pC    ))<<24) |
+                  ((*(pC + 1))<<16) |
+                  ((*(pC + 2))<< 8) |
+                  ((*(pC + 3))    );
 
-   if(profile_size < profile_length)
+   if (profile_size < profile_length)
       profile_length = profile_size;
 
-   if(profile_size > profile_length)
+   if (profile_size > profile_length)
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       png_warning(png_ptr, "Ignoring truncated iCCP profile.");
       return;
    }
 
-   png_set_iCCP(png_ptr, info_ptr, chunkdata, compression_type,
-                chunkdata + prefix_length, profile_length);
-   png_free(png_ptr, chunkdata);
+   png_set_iCCP(png_ptr, info_ptr, png_ptr->chunkdata,
+     compression_type, png_ptr->chunkdata + prefix_length, profile_length);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
 }
 #endif /* PNG_READ_iCCP_SUPPORTED */
 
@@ -1101,7 +1128,6 @@ void /* PRIVATE */
 png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 /* Note: this does not properly handle chunks that are > 64K under DOS */
 {
-   png_bytep chunkdata;
    png_bytep entry_start;
    png_sPLT_t new_palette;
 #ifdef PNG_NO_POINTER_INDEXING
@@ -1131,45 +1157,49 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 #endif
 
-   chunkdata = (png_bytep)png_malloc(png_ptr, length + 1);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc(png_ptr, length + 1);
    slength = (png_size_t)length;
-   png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
 
    if (png_crc_finish(png_ptr, skip))
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
-   chunkdata[slength] = 0x00;
+   png_ptr->chunkdata[slength] = 0x00;
 
-   for (entry_start = chunkdata; *entry_start; entry_start++)
+   for (entry_start = (png_bytep)png_ptr->chunkdata; *entry_start; entry_start++)
       /* empty loop to find end of name */ ;
    ++entry_start;
 
    /* a sample depth should follow the separator, and we should be on it  */
-   if (entry_start > chunkdata + slength - 2)
+   if (entry_start > (png_bytep)png_ptr->chunkdata + slength - 2)
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       png_warning(png_ptr, "malformed sPLT chunk");
       return;
    }
 
    new_palette.depth = *entry_start++;
    entry_size = (new_palette.depth == 8 ? 6 : 10);
-   data_length = (slength - (entry_start - chunkdata));
+   data_length = (slength - (entry_start - (png_bytep)png_ptr->chunkdata));
 
    /* integrity-check the data length */
    if (data_length % entry_size)
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       png_warning(png_ptr, "sPLT chunk has bad length");
       return;
    }
 
    new_palette.nentries = (png_int_32) ( data_length / entry_size);
-   if ((png_uint_32) new_palette.nentries > (png_uint_32) (PNG_SIZE_MAX /
-       png_sizeof(png_sPLT_entry)))
+   if ((png_uint_32) new_palette.nentries >
+       (png_uint_32) (PNG_SIZE_MAX / png_sizeof(png_sPLT_entry)))
    {
        png_warning(png_ptr, "sPLT chunk too long");
        return;
@@ -1227,11 +1257,12 @@ png_handle_sPLT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #endif
 
    /* discard all chunk data except the name and stash that */
-   new_palette.name = (png_charp)chunkdata;
+   new_palette.name = png_ptr->chunkdata;
 
    png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
 
-   png_free(png_ptr, chunkdata);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
    png_free(png_ptr, new_palette.entries);
 }
 #endif /* PNG_READ_sPLT_SUPPORTED */
@@ -1389,7 +1420,7 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       png_ptr->background.index = buf[0];
       if (info_ptr && info_ptr->num_palette)
       {
-          if(buf[0] > info_ptr->num_palette)
+          if (buf[0] > info_ptr->num_palette)
           {
              png_warning(png_ptr, "Incorrect bKGD chunk index value");
              return;
@@ -1565,7 +1596,6 @@ png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 void /* PRIVATE */
 png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   png_charp purpose;
    png_int_32 X0, X1;
    png_byte type, nparams;
    png_charp buf, units, endptr;
@@ -1592,35 +1622,38 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
    png_debug1(2, "Allocating and reading pCAL chunk data (%lu bytes)\n",
       length + 1);
-   purpose = (png_charp)png_malloc_warn(png_ptr, length + 1);
-   if (purpose == NULL)
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
      {
        png_warning(png_ptr, "No memory for pCAL purpose.");
        return;
      }
    slength = (png_size_t)length;
-   png_crc_read(png_ptr, (png_bytep)purpose, slength);
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
 
    if (png_crc_finish(png_ptr, 0))
    {
-      png_free(png_ptr, purpose);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
-   purpose[slength] = 0x00; /* null terminate the last string */
+   png_ptr->chunkdata[slength] = 0x00; /* null terminate the last string */
 
    png_debug(3, "Finding end of pCAL purpose string\n");
-   for (buf = purpose; *buf; buf++)
+   for (buf = png_ptr->chunkdata; *buf; buf++)
       /* empty loop */ ;
 
-   endptr = purpose + slength;
+   endptr = png_ptr->chunkdata + slength;
 
    /* We need to have at least 12 bytes after the purpose string
       in order to get the parameter information. */
    if (endptr <= buf + 12)
    {
       png_warning(png_ptr, "Invalid pCAL data");
-      png_free(png_ptr, purpose);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
@@ -1640,7 +1673,8 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
        (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
    {
       png_warning(png_ptr, "Invalid pCAL parameters for equation type");
-      png_free(png_ptr, purpose);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
    else if (type >= PNG_EQUATION_LAST)
@@ -1652,11 +1686,12 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       /* Empty loop to move past the units string. */ ;
 
    png_debug(3, "Allocating pCAL parameters array\n");
-   params = (png_charpp)png_malloc_warn(png_ptr, (png_uint_32)(nparams
-      *png_sizeof(png_charp))) ;
+   params = (png_charpp)png_malloc_warn(png_ptr,
+      (png_uint_32)(nparams * png_sizeof(png_charp))) ;
    if (params == NULL)
      {
-       png_free(png_ptr, purpose);
+       png_free(png_ptr, png_ptr->chunkdata);
+       png_ptr->chunkdata = NULL;
        png_warning(png_ptr, "No memory for pCAL params.");
        return;
      }
@@ -1674,16 +1709,18 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       if (buf > endptr)
       {
          png_warning(png_ptr, "Invalid pCAL data");
-         png_free(png_ptr, purpose);
+         png_free(png_ptr, png_ptr->chunkdata);
+         png_ptr->chunkdata = NULL;
          png_free(png_ptr, params);
          return;
       }
    }
 
-   png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams,
+   png_set_pCAL(png_ptr, info_ptr, png_ptr->chunkdata, X0, X1, type, nparams,
       units, params);
 
-   png_free(png_ptr, purpose);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
    png_free(png_ptr, params);
 }
 #endif
@@ -1693,7 +1730,7 @@ png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 void /* PRIVATE */
 png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   png_charp buffer, ep;
+   png_charp ep;
 #ifdef PNG_FLOATING_POINT_SUPPORTED
    double width, height;
    png_charp vp;
@@ -1723,86 +1760,89 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
    png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)\n",
       length + 1);
-   buffer = (png_charp)png_malloc_warn(png_ptr, length + 1);
-   if (buffer == NULL)
-     {
-       png_warning(png_ptr, "Out of memory while processing sCAL chunk");
-       return;
-     }
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
+   {
+      png_warning(png_ptr, "Out of memory while processing sCAL chunk");
+      return;
+   }
    slength = (png_size_t)length;
-   png_crc_read(png_ptr, (png_bytep)buffer, slength);
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
 
    if (png_crc_finish(png_ptr, 0))
    {
-      png_free(png_ptr, buffer);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
-   buffer[slength] = 0x00; /* null terminate the last string */
+   png_ptr->chunkdata[slength] = 0x00; /* null terminate the last string */
 
-   ep = buffer + 1;        /* skip unit byte */
+   ep = png_ptr->chunkdata + 1;        /* skip unit byte */
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
    width = png_strtod(png_ptr, ep, &vp);
    if (*vp)
    {
-       png_warning(png_ptr, "malformed width string in sCAL chunk");
-       return;
+      png_warning(png_ptr, "malformed width string in sCAL chunk");
+      return;
    }
 #else
 #ifdef PNG_FIXED_POINT_SUPPORTED
    swidth = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
    if (swidth == NULL)
-     {
-       png_warning(png_ptr, "Out of memory while processing sCAL chunk width");
-       return;
-     }
+   {
+      png_warning(png_ptr, "Out of memory while processing sCAL chunk width");
+      return;
+   }
    png_memcpy(swidth, ep, (png_size_t)png_strlen(ep));
 #endif
 #endif
 
-   for (ep = buffer; *ep; ep++)
+   for (ep = png_ptr->chunkdata; *ep; ep++)
       /* empty loop */ ;
    ep++;
 
-   if (buffer + slength < ep)
+   if (png_ptr->chunkdata + slength < ep)
    {
-       png_warning(png_ptr, "Truncated sCAL chunk");
+      png_warning(png_ptr, "Truncated sCAL chunk");
 #if defined(PNG_FIXED_POINT_SUPPORTED) && \
     !defined(PNG_FLOATING_POINT_SUPPORTED)
-       png_free(png_ptr, swidth);
+      png_free(png_ptr, swidth);
 #endif
-      png_free(png_ptr, buffer);
-       return;
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
+      return;
    }
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
    height = png_strtod(png_ptr, ep, &vp);
    if (*vp)
    {
-       png_warning(png_ptr, "malformed height string in sCAL chunk");
-       return;
+      png_warning(png_ptr, "malformed height string in sCAL chunk");
+      return;
    }
 #else
 #ifdef PNG_FIXED_POINT_SUPPORTED
    sheight = (png_charp)png_malloc_warn(png_ptr, png_strlen(ep) + 1);
    if (sheight == NULL)
-     {
-       png_warning(png_ptr, "Out of memory while processing sCAL chunk height");
-       return;
-     }
+   {
+      png_warning(png_ptr, "Out of memory while processing sCAL chunk height");
+      return;
+   }
    png_memcpy(sheight, ep, (png_size_t)png_strlen(ep));
 #endif
 #endif
 
-   if (buffer + slength < ep
+   if (png_ptr->chunkdata + slength < ep
 #ifdef PNG_FLOATING_POINT_SUPPORTED
       || width <= 0. || height <= 0.
 #endif
       )
    {
       png_warning(png_ptr, "Invalid sCAL data");
-      png_free(png_ptr, buffer);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
 #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
       png_free(png_ptr, swidth);
       png_free(png_ptr, sheight);
@@ -1812,14 +1852,15 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
 
 #ifdef PNG_FLOATING_POINT_SUPPORTED
-   png_set_sCAL(png_ptr, info_ptr, buffer[0], width, height);
+   png_set_sCAL(png_ptr, info_ptr, png_ptr->chunkdata[0], width, height);
 #else
 #ifdef PNG_FIXED_POINT_SUPPORTED
-   png_set_sCAL_s(png_ptr, info_ptr, buffer[0], swidth, sheight);
+   png_set_sCAL_s(png_ptr, info_ptr, png_ptr->chunkdata[0], swidth, sheight);
 #endif
 #endif
 
-   png_free(png_ptr, buffer);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
 #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
    png_free(png_ptr, swidth);
    png_free(png_ptr, sheight);
@@ -1899,21 +1940,24 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 #endif
 
-   key = (png_charp)png_malloc_warn(png_ptr, length + 1);
-   if (key == NULL)
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
    {
      png_warning(png_ptr, "No memory to process text chunk.");
      return;
    }
    slength = (png_size_t)length;
-   png_crc_read(png_ptr, (png_bytep)key, slength);
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
 
    if (png_crc_finish(png_ptr, skip))
    {
-      png_free(png_ptr, key);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
+   key = png_ptr->chunkdata;
    key[slength] = 0x00;
 
    for (text = key; *text; text++)
@@ -1927,7 +1971,8 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (text_ptr == NULL)
    {
      png_warning(png_ptr, "Not enough memory to process text chunk.");
-     png_free(png_ptr, key);
+     png_free(png_ptr, png_ptr->chunkdata);
+     png_ptr->chunkdata = NULL;
      return;
    }
    text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
@@ -1940,9 +1985,10 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    text_ptr->text = text;
    text_ptr->text_length = png_strlen(text);
 
-   ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
 
-   png_free(png_ptr, key);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
    png_free(png_ptr, text_ptr);
    if (ret)
      png_warning(png_ptr, "Insufficient memory to process text chunk.");
@@ -1955,7 +2001,6 @@ void /* PRIVATE */
 png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_textp text_ptr;
-   png_charp chunkdata;
    png_charp text;
    int comp_type;
    int ret;
@@ -1973,36 +2018,39 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       there is no hard and fast rule to tell us where to stop. */
    if (length > (png_uint_32)65535L)
    {
-     png_warning(png_ptr,"zTXt chunk too large to fit in memory");
+     png_warning(png_ptr, "zTXt chunk too large to fit in memory");
      png_crc_finish(png_ptr, length);
      return;
    }
 #endif
 
-   chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
-   if (chunkdata == NULL)
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
    {
-     png_warning(png_ptr,"Out of memory processing zTXt chunk.");
+     png_warning(png_ptr, "Out of memory processing zTXt chunk.");
      return;
    }
    slength = (png_size_t)length;
-   png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
    if (png_crc_finish(png_ptr, 0))
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
-   chunkdata[slength] = 0x00;
+   png_ptr->chunkdata[slength] = 0x00;
 
-   for (text = chunkdata; *text; text++)
+   for (text = png_ptr->chunkdata; *text; text++)
       /* empty loop */ ;
 
    /* zTXt must have some text after the chunkdataword */
-   if (text >= chunkdata + slength - 2)
+   if (text >= png_ptr->chunkdata + slength - 2)
    {
       png_warning(png_ptr, "Truncated zTXt chunk");
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
    else
@@ -2015,33 +2063,35 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
        }
        text++;        /* skip the compression_method byte */
    }
-   prefix_len = text - chunkdata;
+   prefix_len = text - png_ptr->chunkdata;
 
-   chunkdata = (png_charp)png_decompress_chunk(png_ptr, comp_type, chunkdata,
-                                    (png_size_t)length, prefix_len, &data_len);
+   png_decompress_chunk(png_ptr, comp_type,
+     (png_size_t)length, prefix_len, &data_len);
 
    text_ptr = (png_textp)png_malloc_warn(png_ptr,
-     (png_uint_32)png_sizeof(png_text));
+      (png_uint_32)png_sizeof(png_text));
    if (text_ptr == NULL)
    {
-     png_warning(png_ptr,"Not enough memory to process zTXt chunk.");
-     png_free(png_ptr, chunkdata);
+     png_warning(png_ptr, "Not enough memory to process zTXt chunk.");
+     png_free(png_ptr, png_ptr->chunkdata);
+     png_ptr->chunkdata = NULL;
      return;
    }
    text_ptr->compression = comp_type;
-   text_ptr->key = chunkdata;
+   text_ptr->key = png_ptr->chunkdata;
 #ifdef PNG_iTXt_SUPPORTED
    text_ptr->lang = NULL;
    text_ptr->lang_key = NULL;
    text_ptr->itxt_length = 0;
 #endif
-   text_ptr->text = chunkdata + prefix_len;
+   text_ptr->text = png_ptr->chunkdata + prefix_len;
    text_ptr->text_length = data_len;
 
-   ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
 
    png_free(png_ptr, text_ptr);
-   png_free(png_ptr, chunkdata);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
    if (ret)
      png_error(png_ptr, "Insufficient memory to store zTXt chunk.");
 }
@@ -2053,7 +2103,6 @@ void /* PRIVATE */
 png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_textp text_ptr;
-   png_charp chunkdata;
    png_charp key, lang, text, lang_key;
    int comp_flag;
    int comp_type = 0;
@@ -2073,29 +2122,31 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       there is no hard and fast rule to tell us where to stop. */
    if (length > (png_uint_32)65535L)
    {
-     png_warning(png_ptr,"iTXt chunk too large to fit in memory");
+     png_warning(png_ptr, "iTXt chunk too large to fit in memory");
      png_crc_finish(png_ptr, length);
      return;
    }
 #endif
 
-   chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
-   if (chunkdata == NULL)
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
+   if (png_ptr->chunkdata == NULL)
    {
      png_warning(png_ptr, "No memory to process iTXt chunk.");
      return;
    }
    slength = (png_size_t)length;
-   png_crc_read(png_ptr, (png_bytep)chunkdata, slength);
+   png_crc_read(png_ptr, (png_bytep)png_ptr->chunkdata, slength);
    if (png_crc_finish(png_ptr, 0))
    {
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
-   chunkdata[slength] = 0x00;
+   png_ptr->chunkdata[slength] = 0x00;
 
-   for (lang = chunkdata; *lang; lang++)
+   for (lang = png_ptr->chunkdata; *lang; lang++)
       /* empty loop */ ;
    lang++;        /* skip NUL separator */
 
@@ -2103,10 +2154,11 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       translated keyword (possibly empty), and possibly some text after the
       keyword */
 
-   if (lang >= chunkdata + slength - 3)
+   if (lang >= png_ptr->chunkdata + slength - 3)
    {
       png_warning(png_ptr, "Truncated iTXt chunk");
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
    else
@@ -2119,51 +2171,55 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       /* empty loop */ ;
    lang_key++;        /* skip NUL separator */
 
-   if (lang_key >= chunkdata + slength)
+   if (lang_key >= png_ptr->chunkdata + slength)
    {
       png_warning(png_ptr, "Truncated iTXt chunk");
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
    for (text = lang_key; *text; text++)
       /* empty loop */ ;
    text++;        /* skip NUL separator */
-   if (text >= chunkdata + slength)
+   if (text >= png_ptr->chunkdata + slength)
    {
       png_warning(png_ptr, "Malformed iTXt chunk");
-      png_free(png_ptr, chunkdata);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
       return;
    }
 
-   prefix_len = text - chunkdata;
+   prefix_len = text - png_ptr->chunkdata;
 
-   key=chunkdata;
+   key=png_ptr->chunkdata;
    if (comp_flag)
-       chunkdata = png_decompress_chunk(png_ptr, comp_type, chunkdata,
-          (size_t)length, prefix_len, &data_len);
+       png_decompress_chunk(png_ptr, comp_type,
+         (size_t)length, prefix_len, &data_len);
    else
-       data_len=png_strlen(chunkdata + prefix_len);
+       data_len = png_strlen(png_ptr->chunkdata + prefix_len);
    text_ptr = (png_textp)png_malloc_warn(png_ptr,
       (png_uint_32)png_sizeof(png_text));
    if (text_ptr == NULL)
    {
-     png_warning(png_ptr,"Not enough memory to process iTXt chunk.");
-     png_free(png_ptr, chunkdata);
+     png_warning(png_ptr, "Not enough memory to process iTXt chunk.");
+     png_free(png_ptr, png_ptr->chunkdata);
+     png_ptr->chunkdata = NULL;
      return;
    }
    text_ptr->compression = (int)comp_flag + 1;
-   text_ptr->lang_key = chunkdata+(lang_key-key);
-   text_ptr->lang = chunkdata+(lang-key);
+   text_ptr->lang_key = png_ptr->chunkdata + (lang_key - key);
+   text_ptr->lang = png_ptr->chunkdata + (lang - key);
    text_ptr->itxt_length = data_len;
    text_ptr->text_length = 0;
-   text_ptr->key = chunkdata;
-   text_ptr->text = chunkdata + prefix_len;
+   text_ptr->key = png_ptr->chunkdata;
+   text_ptr->text = png_ptr->chunkdata + prefix_len;
 
-   ret=png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
 
    png_free(png_ptr, text_ptr);
-   png_free(png_ptr, chunkdata);
+   png_free(png_ptr, png_ptr->chunkdata);
+   png_ptr->chunkdata = NULL;
    if (ret)
      png_error(png_ptr, "Insufficient memory to store iTXt chunk.");
 }
@@ -2190,12 +2246,10 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
          png_ptr->mode |= PNG_AFTER_IDAT;
    }
 
-   png_check_chunk_name(png_ptr, png_ptr->chunk_name);
-
    if (!(png_ptr->chunk_name[0] & 0x20))
    {
 #if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
-      if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+      if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
            PNG_HANDLE_CHUNK_ALWAYS
 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
            && png_ptr->read_user_chunk_fn == NULL
@@ -2230,7 +2284,7 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
          png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
        }
 #if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
-       if(png_ptr->read_user_chunk_fn != NULL)
+       if (png_ptr->read_user_chunk_fn != NULL)
        {
           /* callback to user unknown chunk handler */
           int ret;
@@ -2241,7 +2295,7 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
           if (ret == 0)
           {
              if (!(png_ptr->chunk_name[0] & 0x20))
-                if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+                if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
                      PNG_HANDLE_CHUNK_ALWAYS)
                    png_chunk_error(png_ptr, "unknown critical chunk");
              png_set_unknown_chunks(png_ptr, info_ptr,
@@ -2298,7 +2352,7 @@ png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
 void /* PRIVATE */
 png_combine_row(png_structp png_ptr, png_bytep row, int mask)
 {
-   png_debug(1,"in png_combine_row\n");
+   png_debug(1, "in png_combine_row\n");
    if (mask == 0xff)
    {
       png_memcpy(row, png_ptr->row_buf + 1,
@@ -2514,7 +2568,7 @@ png_do_read_interlace(png_structp png_ptr)
    PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
 #endif
 
-   png_debug(1,"in png_do_read_interlace\n");
+   png_debug(1, "in png_do_read_interlace\n");
    if (row != NULL && row_info != NULL)
    {
       png_uint_32 final_width;
@@ -2715,7 +2769,7 @@ png_do_read_interlace(png_structp png_ptr)
          }
       }
       row_info->width = final_width;
-      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,final_width);
+      row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
    }
 #if !defined(PNG_READ_PACKSWAP_SUPPORTED)
    transformations = transformations; /* silence compiler warning */
@@ -2728,7 +2782,7 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
    png_bytep prev_row, int filter)
 {
    png_debug(1, "in png_read_filter_row\n");
-   png_debug2(2,"row = %lu, filter = %d\n", png_ptr->row_number, filter);
+   png_debug2(2, "row = %lu, filter = %d\n", png_ptr->row_number, filter);
    switch (filter)
    {
       case PNG_FILTER_VALUE_NONE:
@@ -2832,7 +2886,7 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
                   p = c;
              */
 
-            p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
+            p = (pa <= pb && pa <= pc) ? a : (pb <= pc) ? b : c;
 
             *rp = (png_byte)(((int)(*rp) + p) & 0xff);
             rp++;
@@ -2841,7 +2895,7 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
       }
       default:
          png_warning(png_ptr, "Ignoring bad adaptive filter type");
-         *row=0;
+         *row = 0;
          break;
    }
 }
@@ -2919,7 +2973,7 @@ png_read_finish_row(png_structp png_ptr)
 
       png_ptr->zstream.next_out = (Byte *)&extra;
       png_ptr->zstream.avail_out = (uInt)1;
-      for(;;)
+      for (;;)
       {
          if (!(png_ptr->zstream.avail_in))
          {
@@ -3000,7 +3054,7 @@ png_read_start_row(png_structp png_ptr)
 #endif
 
    int max_pixel_depth;
-   png_uint_32 row_bytes;
+   png_size_t row_bytes;
 
    png_debug(1, "in png_read_start_row\n");
    png_ptr->zstream.avail_in = 0;
@@ -3019,11 +3073,8 @@ png_read_start_row(png_structp png_ptr)
          png_pass_start[png_ptr->pass]) /
          png_pass_inc[png_ptr->pass];
 
-         row_bytes = PNG_ROWBYTES(png_ptr->pixel_depth,png_ptr->iwidth) + 1;
-
-         png_ptr->irowbytes = (png_size_t)row_bytes;
-         if((png_uint_32)png_ptr->irowbytes != row_bytes)
-            png_error(png_ptr, "Rowbytes overflow in png_read_start_row");
+         png_ptr->irowbytes =
+            PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1;
    }
    else
 #endif /* PNG_READ_INTERLACING_SUPPORTED */
@@ -3125,11 +3176,11 @@ png_read_start_row(png_structp png_ptr)
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
 defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
-   if(png_ptr->transformations & PNG_USER_TRANSFORM)
+   if (png_ptr->transformations & PNG_USER_TRANSFORM)
      {
-       int user_pixel_depth=png_ptr->user_transform_depth*
+       int user_pixel_depth = png_ptr->user_transform_depth*
          png_ptr->user_transform_channels;
-       if(user_pixel_depth > max_pixel_depth)
+       if (user_pixel_depth > max_pixel_depth)
          max_pixel_depth=user_pixel_depth;
      }
 #endif
@@ -3139,16 +3190,16 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
    row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
    /* calculate the maximum bytes needed, adding a byte and a pixel
       for safety's sake */
-   row_bytes = PNG_ROWBYTES(max_pixel_depth,row_bytes) +
+   row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
       1 + ((max_pixel_depth + 7) >> 3);
 #ifdef PNG_MAX_MALLOC_64K
    if (row_bytes > (png_uint_32)65536L)
       png_error(png_ptr, "This image requires a row greater than 64KB");
 #endif
 
-   if(row_bytes + 64 > png_ptr->old_big_row_buf_size)
+   if (row_bytes + 64 > png_ptr->old_big_row_buf_size)
    {
-     png_free(png_ptr,png_ptr->big_row_buf);
+     png_free(png_ptr, png_ptr->big_row_buf);
      png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes+64);
      png_ptr->row_buf = png_ptr->big_row_buf+32;
      png_ptr->old_big_row_buf_size = row_bytes+64;
@@ -3161,9 +3212,9 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
    if ((png_uint_32)png_ptr->rowbytes > (png_uint_32)(PNG_SIZE_MAX - 1))
       png_error(png_ptr, "Row has too many bytes to allocate in memory.");
 
-   if(png_ptr->rowbytes+1 > png_ptr->old_prev_row_size)
+   if (png_ptr->rowbytes+1 > png_ptr->old_prev_row_size)
    {
-     png_free(png_ptr,png_ptr->prev_row);
+     png_free(png_ptr, png_ptr->prev_row);
      png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)(
         png_ptr->rowbytes + 1));
      png_ptr->old_prev_row_size = png_ptr->rowbytes+1;
diff --git a/third_party/libpng/pngset.c b/third_party/libpng/pngset.c
index 8b25ca5..4893671 100644
--- a/third_party/libpng/pngset.c
+++ b/third_party/libpng/pngset.c
@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.2.27 [April 29, 2008]
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -15,7 +15,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
 #if defined(PNG_bKGD_SUPPORTED)
@@ -168,13 +167,13 @@ png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma)
       gamma=21474.83;
    }
    else
-      gamma=file_gamma;
+      gamma = file_gamma;
    info_ptr->gamma = (float)gamma;
 #ifdef PNG_FIXED_POINT_SUPPORTED
    info_ptr->int_gamma = (int)(gamma*100000.+.5);
 #endif
    info_ptr->valid |= PNG_INFO_gAMA;
-   if(gamma == 0.0)
+   if (gamma == 0.0)
       png_warning(png_ptr, "Setting gamma=0");
 }
 #endif
@@ -198,10 +197,10 @@ png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
      if (int_gamma < 0)
      {
        png_warning(png_ptr, "Setting negative gamma to zero");
-       gamma=0;
+       gamma = 0;
      }
      else
-       gamma=int_gamma;
+       gamma = int_gamma;
    }
 #ifdef PNG_FLOATING_POINT_SUPPORTED
    info_ptr->gamma = (float)(gamma/100000.);
@@ -210,7 +209,7 @@ png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
    info_ptr->int_gamma = gamma;
 #endif
    info_ptr->valid |= PNG_INFO_gAMA;
-   if(gamma == 0)
+   if (gamma == 0)
       png_warning(png_ptr, "Setting gamma=0");
 }
 #endif
@@ -238,7 +237,7 @@ png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p hist)
    /* Changed from info->num_palette to PNG_MAX_PALETTE_LENGTH in version
       1.2.1 */
    png_ptr->hist = (png_uint_16p)png_malloc_warn(png_ptr,
-      (png_uint_32)(PNG_MAX_PALETTE_LENGTH * png_sizeof (png_uint_16)));
+      (png_uint_32)(PNG_MAX_PALETTE_LENGTH * png_sizeof(png_uint_16)));
    if (png_ptr->hist == NULL)
      {
        png_warning(png_ptr, "Insufficient memory for hIST chunk data.");
@@ -319,21 +318,21 @@ png_set_IHDR(png_structp png_ptr, png_infop info_ptr,
     * 4. The filter_method is 64 and
     * 5. The color_type is RGB or RGBA
     */
-   if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&png_ptr->mng_features_permitted)
-      png_warning(png_ptr,"MNG features are not allowed in a PNG datastream");
-   if(filter_type != PNG_FILTER_TYPE_BASE)
+   if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&png_ptr->mng_features_permitted)
+      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
+   if (filter_type != PNG_FILTER_TYPE_BASE)
    {
-     if(!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+     if (!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
         (filter_type == PNG_INTRAPIXEL_DIFFERENCING) &&
         ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
         (color_type == PNG_COLOR_TYPE_RGB ||
          color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
         png_error(png_ptr, "Unknown filter method in IHDR");
-     if(png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)
+     if (png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)
         png_warning(png_ptr, "Invalid filter method in IHDR");
    }
 #else
-   if(filter_type != PNG_FILTER_TYPE_BASE)
+   if (filter_type != PNG_FILTER_TYPE_BASE)
       png_error(png_ptr, "Unknown filter method in IHDR");
 #endif
 
@@ -363,7 +362,7 @@ png_set_IHDR(png_structp png_ptr, png_infop info_ptr,
                  - 8)       /* extra max_pixel_depth pad */
       info_ptr->rowbytes = (png_size_t)0;
    else
-      info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth,width);
+      info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, width);
 }
 
 #if defined(PNG_oFFs_SUPPORTED)
@@ -396,13 +395,14 @@ png_set_pCAL(png_structp png_ptr, png_infop info_ptr,
       return;
 
    length = png_strlen(purpose) + 1;
-   png_debug1(3, "allocating purpose for info (%lu bytes)\n", length);
+   png_debug1(3, "allocating purpose for info (%lu bytes)\n",
+     (unsigned long)length);
    info_ptr->pcal_purpose = (png_charp)png_malloc_warn(png_ptr, length);
    if (info_ptr->pcal_purpose == NULL)
-     {
+   {
        png_warning(png_ptr, "Insufficient memory for pCAL purpose.");
-       return;
-     }
+      return;
+   }
    png_memcpy(info_ptr->pcal_purpose, purpose, (png_size_t)length);
 
    png_debug(3, "storing X0, X1, type, and nparams in info\n");
@@ -412,35 +412,37 @@ png_set_pCAL(png_structp png_ptr, png_infop info_ptr,
    info_ptr->pcal_nparams = (png_byte)nparams;
 
    length = png_strlen(units) + 1;
-   png_debug1(3, "allocating units for info (%lu bytes)\n", length);
+   png_debug1(3, "allocating units for info (%lu bytes)\n",
+     (unsigned long)length);
    info_ptr->pcal_units = (png_charp)png_malloc_warn(png_ptr, length);
    if (info_ptr->pcal_units == NULL)
-     {
+   {
        png_warning(png_ptr, "Insufficient memory for pCAL units.");
-       return;
-     }
+      return;
+   }
    png_memcpy(info_ptr->pcal_units, units, (png_size_t)length);
 
    info_ptr->pcal_params = (png_charpp)png_malloc_warn(png_ptr,
       (png_uint_32)((nparams + 1) * png_sizeof(png_charp)));
    if (info_ptr->pcal_params == NULL)
-     {
+   {
        png_warning(png_ptr, "Insufficient memory for pCAL params.");
-       return;
-     }
+      return;
+   }
 
    info_ptr->pcal_params[nparams] = NULL;
 
    for (i = 0; i < nparams; i++)
    {
       length = png_strlen(params[i]) + 1;
-      png_debug2(3, "allocating parameter %d for info (%lu bytes)\n", i, length);
+      png_debug2(3, "allocating parameter %d for info (%lu bytes)\n", i,
+        (unsigned long)length);
       info_ptr->pcal_params[i] = (png_charp)png_malloc_warn(png_ptr, length);
       if (info_ptr->pcal_params[i] == NULL)
-        {
+      {
           png_warning(png_ptr, "Insufficient memory for pCAL parameter.");
           return;
-        }
+      }
       png_memcpy(info_ptr->pcal_params[i], params[i], (png_size_t)length);
    }
 
@@ -482,7 +484,8 @@ png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
    info_ptr->scal_unit = (png_byte)unit;
 
    length = png_strlen(swidth) + 1;
-   png_debug1(3, "allocating unit for info (%d bytes)\n", length);
+   png_debug1(3, "allocating unit for info (%u bytes)\n",
+      (unsigned int)length);
    info_ptr->scal_s_width = (png_charp)png_malloc_warn(png_ptr, length);
    if (info_ptr->scal_s_width == NULL)
    {
@@ -493,11 +496,13 @@ png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
    png_memcpy(info_ptr->scal_s_width, swidth, (png_size_t)length);
 
    length = png_strlen(sheight) + 1;
-   png_debug1(3, "allocating unit for info (%d bytes)\n", length);
+   png_debug1(3, "allocating unit for info (%u bytes)\n",
+      (unsigned int)length);
    info_ptr->scal_s_height = (png_charp)png_malloc_warn(png_ptr, length);
    if (info_ptr->scal_s_height == NULL)
    {
       png_free (png_ptr, info_ptr->scal_s_width);
+      info_ptr->scal_s_width = NULL;
       png_warning(png_ptr,
        "Memory allocation failed while processing sCAL.");
       return;
@@ -564,7 +569,7 @@ png_set_PLTE(png_structp png_ptr, png_infop info_ptr,
       PNG_MAX_PALETTE_LENGTH * png_sizeof(png_color));
    png_memset(png_ptr->palette, 0, PNG_MAX_PALETTE_LENGTH *
       png_sizeof(png_color));
-   png_memcpy(png_ptr->palette, palette, num_palette * png_sizeof (png_color));
+   png_memcpy(png_ptr->palette, palette, num_palette * png_sizeof(png_color));
    info_ptr->palette = png_ptr->palette;
    info_ptr->num_palette = png_ptr->num_palette = (png_uint_16)num_palette;
 
@@ -586,7 +591,7 @@ png_set_sBIT(png_structp png_ptr, png_infop info_ptr,
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   png_memcpy(&(info_ptr->sig_bit), sig_bit, png_sizeof (png_color_8));
+   png_memcpy(&(info_ptr->sig_bit), sig_bit, png_sizeof(png_color_8));
    info_ptr->valid |= PNG_INFO_sBIT;
 }
 #endif
@@ -700,7 +705,8 @@ png_set_iCCP(png_structp png_ptr, png_infop info_ptr,
    if (new_iccp_profile == NULL)
    {
       png_free (png_ptr, new_iccp_name);
-      png_warning(png_ptr, "Insufficient memory to process iCCP profile.");
+      png_warning(png_ptr,
+      "Insufficient memory to process iCCP profile.");
       return;
    }
    png_memcpy(new_iccp_profile, profile, (png_size_t)proflen);
@@ -726,7 +732,7 @@ png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
    int num_text)
 {
    int ret;
-   ret=png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
+   ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
    if (ret)
      png_error(png_ptr, "Insufficient memory to store text");
 }
@@ -757,7 +763,7 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
          info_ptr->max_text = info_ptr->num_text + num_text + 8;
          old_text = info_ptr->text;
          info_ptr->text = (png_textp)png_malloc_warn(png_ptr,
-            (png_uint_32)(info_ptr->max_text * png_sizeof (png_text)));
+            (png_uint_32)(info_ptr->max_text * png_sizeof(png_text)));
          if (info_ptr->text == NULL)
            {
              png_free(png_ptr, old_text);
@@ -772,7 +778,7 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
          info_ptr->max_text = num_text + 8;
          info_ptr->num_text = 0;
          info_ptr->text = (png_textp)png_malloc_warn(png_ptr,
-            (png_uint_32)(info_ptr->max_text * png_sizeof (png_text)));
+            (png_uint_32)(info_ptr->max_text * png_sizeof(png_text)));
          if (info_ptr->text == NULL)
            return(1);
 #ifdef PNG_FREE_ME_SUPPORTED
@@ -784,8 +790,8 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
    }
    for (i = 0; i < num_text; i++)
    {
-      png_size_t text_length,key_len;
-      png_size_t lang_len,lang_key_len;
+      png_size_t text_length, key_len;
+      png_size_t lang_len, lang_key_len;
       png_textp textp = &(info_ptr->text[info_ptr->num_text]);
 
       if (text_ptr[i].key == NULL)
@@ -793,7 +799,7 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
 
       key_len = png_strlen(text_ptr[i].key);
 
-      if(text_ptr[i].compression <= 0)
+      if (text_ptr[i].compression <= 0)
       {
         lang_len = 0;
         lang_key_len = 0;
@@ -822,7 +828,7 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
       {
          text_length = 0;
 #ifdef PNG_iTXt_SUPPORTED
-         if(text_ptr[i].compression > 0)
+         if (text_ptr[i].compression > 0)
             textp->compression = PNG_ITXT_COMPRESSION_NONE;
          else
 #endif
@@ -835,26 +841,28 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
       }
 
       textp->key = (png_charp)png_malloc_warn(png_ptr,
-         (png_uint_32)(key_len + text_length + lang_len + lang_key_len + 4));
+         (png_uint_32)
+         (key_len + text_length + lang_len + lang_key_len + 4));
       if (textp->key == NULL)
         return(1);
       png_debug2(2, "Allocated %lu bytes at %x in png_set_text\n",
-         (png_uint_32)(key_len + lang_len + lang_key_len + text_length + 4),
+         (png_uint_32)
+         (key_len + lang_len + lang_key_len + text_length + 4),
          (int)textp->key);
 
       png_memcpy(textp->key, text_ptr[i].key,
          (png_size_t)(key_len));
-      *(textp->key+key_len) = '\0';
+      *(textp->key + key_len) = '\0';
 #ifdef PNG_iTXt_SUPPORTED
       if (text_ptr[i].compression > 0)
       {
-         textp->lang=textp->key + key_len + 1;
+         textp->lang = textp->key + key_len + 1;
          png_memcpy(textp->lang, text_ptr[i].lang, lang_len);
-         *(textp->lang+lang_len) = '\0';
-         textp->lang_key=textp->lang + lang_len + 1;
+         *(textp->lang + lang_len) = '\0';
+         textp->lang_key = textp->lang + lang_len + 1;
          png_memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
-         *(textp->lang_key+lang_key_len) = '\0';
-         textp->text=textp->lang_key + lang_key_len + 1;
+         *(textp->lang_key + lang_key_len) = '\0';
+         textp->text = textp->lang_key + lang_key_len + 1;
       }
       else
 #endif
@@ -863,15 +871,15 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
          textp->lang=NULL;
          textp->lang_key=NULL;
 #endif
-         textp->text=textp->key + key_len + 1;
+         textp->text = textp->key + key_len + 1;
       }
-      if(text_length)
+      if (text_length)
          png_memcpy(textp->text, text_ptr[i].text,
             (png_size_t)(text_length));
-      *(textp->text+text_length) = '\0';
+      *(textp->text + text_length) = '\0';
 
 #ifdef PNG_iTXt_SUPPORTED
-      if(textp->compression > 0)
+      if (textp->compression > 0)
       {
          textp->text_length = 0;
          textp->itxt_length = text_length;
@@ -900,7 +908,7 @@ png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_timep mod_time)
        (png_ptr->mode & PNG_WROTE_tIME))
       return;
 
-   png_memcpy(&(info_ptr->mod_time), mod_time, png_sizeof (png_time));
+   png_memcpy(&(info_ptr->mod_time), mod_time, png_sizeof(png_time));
    info_ptr->valid |= PNG_INFO_tIME;
 }
 #endif
@@ -914,8 +922,6 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
-
    if (trans != NULL)
    {
        /*
@@ -924,6 +930,10 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
         * function used to do the allocation.
         */
 
+#ifdef PNG_FREE_ME_SUPPORTED
+       png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+#endif
+
        /* Changed from num_trans to PNG_MAX_PALETTE_LENGTH in version 1.2.1 */
        png_ptr->trans = info_ptr->trans = (png_bytep)png_malloc(png_ptr,
            (png_uint_32)PNG_MAX_PALETTE_LENGTH);
@@ -965,6 +975,13 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
 void PNGAPI
 png_set_sPLT(png_structp png_ptr,
              png_infop info_ptr, png_sPLT_tp entries, int nentries)
+/*
+ *  entries        - array of png_sPLT_t structures
+ *                   to be added to the list of palettes
+ *                   in the info structure.
+ *  nentries       - number of palette structures to be
+ *                   added.
+ */
 {
     png_sPLT_tp np;
     int i;
@@ -973,7 +990,8 @@ png_set_sPLT(png_structp png_ptr,
        return;
 
     np = (png_sPLT_tp)png_malloc_warn(png_ptr,
-        (info_ptr->splt_palettes_num + nentries) * png_sizeof(png_sPLT_t));
+        (info_ptr->splt_palettes_num + nentries) *
+        (png_uint_32)png_sizeof(png_sPLT_t));
     if (np == NULL)
     {
       png_warning(png_ptr, "No memory for sPLT palettes.");
@@ -1001,12 +1019,12 @@ png_set_sPLT(png_structp png_ptr,
         }
         png_memcpy(to->name, from->name, length);
         to->entries = (png_sPLT_entryp)png_malloc_warn(png_ptr,
-            from->nentries * png_sizeof(png_sPLT_entry));
+            (png_uint_32)(from->nentries * png_sizeof(png_sPLT_entry)));
         if (to->entries == NULL)
         {
            png_warning(png_ptr,
              "Out of memory while processing sPLT chunk");
-           png_free(png_ptr,to->name);
+           png_free(png_ptr, to->name);
            to->name = NULL;
            continue;
         }
@@ -1037,8 +1055,8 @@ png_set_unknown_chunks(png_structp png_ptr,
         return;
 
     np = (png_unknown_chunkp)png_malloc_warn(png_ptr,
-        (info_ptr->unknown_chunks_num + num_unknowns) *
-        png_sizeof(png_unknown_chunk));
+        (png_uint_32)((info_ptr->unknown_chunks_num + num_unknowns) *
+        png_sizeof(png_unknown_chunk)));
     if (np == NULL)
     {
        png_warning(png_ptr,
@@ -1068,12 +1086,13 @@ png_set_unknown_chunks(png_structp png_ptr,
           to->data=NULL;
        else
        {
-          to->data = (png_bytep)png_malloc_warn(png_ptr, from->size);
+          to->data = (png_bytep)png_malloc_warn(png_ptr,
+            (png_uint_32)from->size);
           if (to->data == NULL)
           {
              png_warning(png_ptr,
               "Out of memory while processing unknown chunk.");
-             to->size=0;
+             to->size = 0;
           }
           else
              png_memcpy(to->data, from->data, from->size);
@@ -1090,7 +1109,7 @@ void PNGAPI
 png_set_unknown_chunk_location(png_structp png_ptr, png_infop info_ptr,
    int chunk, int location)
 {
-   if(png_ptr != NULL && info_ptr != NULL && chunk >= 0 && chunk <
+   if (png_ptr != NULL && info_ptr != NULL && chunk >= 0 && chunk <
          (int)info_ptr->unknown_chunks_num)
       info_ptr->unknown_chunks[chunk].location = (png_byte)location;
 }
@@ -1138,12 +1157,12 @@ png_set_keep_unknown_chunks(png_structp png_ptr, int keep, png_bytep
        return;
     if (num_chunks == 0)
     {
-      if(keep == PNG_HANDLE_CHUNK_ALWAYS || keep == PNG_HANDLE_CHUNK_IF_SAFE)
+      if (keep == PNG_HANDLE_CHUNK_ALWAYS || keep == PNG_HANDLE_CHUNK_IF_SAFE)
         png_ptr->flags |= PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
       else
         png_ptr->flags &= ~PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
 
-      if(keep == PNG_HANDLE_CHUNK_ALWAYS)
+      if (keep == PNG_HANDLE_CHUNK_ALWAYS)
         png_ptr->flags |= PNG_FLAG_KEEP_UNSAFE_CHUNKS;
       else
         png_ptr->flags &= ~PNG_FLAG_KEEP_UNSAFE_CHUNKS;
@@ -1151,22 +1170,23 @@ png_set_keep_unknown_chunks(png_structp png_ptr, int keep, png_bytep
     }
     if (chunk_list == NULL)
       return;
-    old_num_chunks=png_ptr->num_chunk_list;
+    old_num_chunks = png_ptr->num_chunk_list;
     new_list=(png_bytep)png_malloc(png_ptr,
-       (png_uint_32)(5*(num_chunks+old_num_chunks)));
-    if(png_ptr->chunk_list != NULL)
+       (png_uint_32)
+       (5*(num_chunks + old_num_chunks)));
+    if (png_ptr->chunk_list != NULL)
     {
        png_memcpy(new_list, png_ptr->chunk_list,
           (png_size_t)(5*old_num_chunks));
        png_free(png_ptr, png_ptr->chunk_list);
        png_ptr->chunk_list=NULL;
     }
-    png_memcpy(new_list+5*old_num_chunks, chunk_list,
+    png_memcpy(new_list + 5*old_num_chunks, chunk_list,
        (png_size_t)(5*num_chunks));
-    for (p=new_list+5*old_num_chunks+4, i=0; i<num_chunks; i++, p+=5)
+    for (p = new_list + 5*old_num_chunks + 4, i = 0; i<num_chunks; i++, p += 5)
        *p=(png_byte)keep;
-    png_ptr->num_chunk_list=old_num_chunks+num_chunks;
-    png_ptr->chunk_list=new_list;
+    png_ptr->num_chunk_list = old_num_chunks + num_chunks;
+    png_ptr->chunk_list = new_list;
 #ifdef PNG_FREE_ME_SUPPORTED
     png_ptr->free_me |= PNG_FREE_LIST;
 #endif
@@ -1195,17 +1215,18 @@ png_set_rows(png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers)
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   if(info_ptr->row_pointers && (info_ptr->row_pointers != row_pointers))
+   if (info_ptr->row_pointers && (info_ptr->row_pointers != row_pointers))
       png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
    info_ptr->row_pointers = row_pointers;
-   if(row_pointers)
+   if (row_pointers)
       info_ptr->valid |= PNG_INFO_IDAT;
 }
 #endif
 
 #ifdef PNG_WRITE_SUPPORTED
 void PNGAPI
-png_set_compression_buffer_size(png_structp png_ptr, png_uint_32 size)
+png_set_compression_buffer_size(png_structp png_ptr,
+    png_uint_32 size)
 {
     if (png_ptr == NULL)
        return;
@@ -1234,6 +1255,7 @@ png_set_asm_flags (png_structp png_ptr, png_uint_32 asm_flags)
 /* Obsolete as of libpng-1.2.20 and will be removed from libpng-1.4.0 */
     if (png_ptr != NULL)
     png_ptr->asm_flags = 0;
+    asm_flags = asm_flags; /* Quiet the compiler */
 }
 
 /* this function was added to libpng 1.2.0 */
@@ -1245,6 +1267,9 @@ png_set_mmx_thresholds (png_structp png_ptr,
 /* Obsolete as of libpng-1.2.20 and will be removed from libpng-1.4.0 */
     if (png_ptr == NULL)
        return;
+    /* Quiet the compiler */
+    mmx_bitdepth_threshold = mmx_bitdepth_threshold;
+    mmx_rowbytes_threshold = mmx_rowbytes_threshold;
 }
 #endif /* ?PNG_ASSEMBLER_CODE_SUPPORTED */
 
@@ -1258,7 +1283,7 @@ png_set_user_limits (png_structp png_ptr, png_uint_32 user_width_max,
      * rejected by png_set_IHDR().  To accept any PNG datastream
      * regardless of dimensions, set both limits to 0x7ffffffL.
      */
-    if(png_ptr == NULL) return;
+    if (png_ptr == NULL) return;
     png_ptr->user_width_max = user_width_max;
     png_ptr->user_height_max = user_height_max;
 }
diff --git a/third_party/libpng/pngtrans.c b/third_party/libpng/pngtrans.c
index 1640095..368d4ec 100644
--- a/third_party/libpng/pngtrans.c
+++ b/third_party/libpng/pngtrans.c
@@ -1,24 +1,24 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.2.17 May 15, 2007
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2007 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2008 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.)
  */
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
 /* turn on BGR-to-RGB mapping */
 void PNGAPI
 png_set_bgr(png_structp png_ptr)
 {
    png_debug(1, "in png_set_bgr\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_BGR;
 }
 #endif
@@ -29,7 +29,7 @@ void PNGAPI
 png_set_swap(png_structp png_ptr)
 {
    png_debug(1, "in png_set_swap\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (png_ptr->bit_depth == 16)
       png_ptr->transformations |= PNG_SWAP_BYTES;
 }
@@ -41,7 +41,7 @@ void PNGAPI
 png_set_packing(png_structp png_ptr)
 {
    png_debug(1, "in png_set_packing\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (png_ptr->bit_depth < 8)
    {
       png_ptr->transformations |= PNG_PACK;
@@ -56,7 +56,7 @@ void PNGAPI
 png_set_packswap(png_structp png_ptr)
 {
    png_debug(1, "in png_set_packswap\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (png_ptr->bit_depth < 8)
       png_ptr->transformations |= PNG_PACKSWAP;
 }
@@ -67,7 +67,7 @@ void PNGAPI
 png_set_shift(png_structp png_ptr, png_color_8p true_bits)
 {
    png_debug(1, "in png_set_shift\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_SHIFT;
    png_ptr->shift = *true_bits;
 }
@@ -99,7 +99,7 @@ void PNGAPI
 png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 {
    png_debug(1, "in png_set_filler\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_FILLER;
    png_ptr->filler = (png_byte)filler;
    if (filler_loc == PNG_FILLER_AFTER)
@@ -132,7 +132,7 @@ void PNGAPI
 png_set_add_alpha(png_structp png_ptr, png_uint_32 filler, int filler_loc)
 {
    png_debug(1, "in png_set_add_alpha\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_set_filler(png_ptr, filler, filler_loc);
    png_ptr->transformations |= PNG_ADD_ALPHA;
 }
@@ -146,7 +146,7 @@ void PNGAPI
 png_set_swap_alpha(png_structp png_ptr)
 {
    png_debug(1, "in png_set_swap_alpha\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_SWAP_ALPHA;
 }
 #endif
@@ -157,7 +157,7 @@ void PNGAPI
 png_set_invert_alpha(png_structp png_ptr)
 {
    png_debug(1, "in png_set_invert_alpha\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_INVERT_ALPHA;
 }
 #endif
@@ -167,7 +167,7 @@ void PNGAPI
 png_set_invert_mono(png_structp png_ptr)
 {
    png_debug(1, "in png_set_invert_mono\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->transformations |= PNG_INVERT_MONO;
 }
 
@@ -631,13 +631,13 @@ png_set_user_transform_info(png_structp png_ptr, png_voidp
    user_transform_ptr, int user_transform_depth, int user_transform_channels)
 {
    png_debug(1, "in png_set_user_transform_info\n");
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
    png_ptr->user_transform_ptr = user_transform_ptr;
    png_ptr->user_transform_depth = (png_byte)user_transform_depth;
    png_ptr->user_transform_channels = (png_byte)user_transform_channels;
 #else
-   if(user_transform_ptr || user_transform_depth || user_transform_channels)
+   if (user_transform_ptr || user_transform_depth || user_transform_channels)
       png_warning(png_ptr,
         "This version of libpng does not support user transform info");
 #endif
@@ -652,8 +652,8 @@ png_set_user_transform_info(png_structp png_ptr, png_voidp
 png_voidp PNGAPI
 png_get_user_transform_ptr(png_structp png_ptr)
 {
-#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
    if (png_ptr == NULL) return (NULL);
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
    return ((png_voidp)png_ptr->user_transform_ptr);
 #else
    return (NULL);
diff --git a/third_party/libpng/pngwio.c b/third_party/libpng/pngwio.c
index 371a4fa..1afbe93 100644
--- a/third_party/libpng/pngwio.c
+++ b/third_party/libpng/pngwio.c
@@ -1,9 +1,9 @@
 
 /* pngwio.c - functions for data output
  *
- * Last changed in libpng 1.2.13 November 13, 2006
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2006 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2008 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.)
  *
@@ -45,7 +45,7 @@ png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
    png_uint_32 check;
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 #if defined(_WIN32_WCE)
    if ( !WriteFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
       check = 0;
@@ -71,7 +71,7 @@ png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
    png_byte *near_data;  /* Needs to be "png_byte *" instead of "png_bytep" */
    png_FILE_p io_ptr;
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    /* Check if data really is near. If so, use usual code. */
    near_data = (png_byte *)CVT_PTR_NOCHECK(data);
    io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
@@ -134,7 +134,7 @@ png_default_flush(png_structp png_ptr)
 #if !defined(_WIN32_WCE)
    png_FILE_p io_ptr;
 #endif
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 #if !defined(_WIN32_WCE)
    io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
    if (io_ptr != NULL)
@@ -170,7 +170,7 @@ void PNGAPI
 png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_ptr->io_ptr = io_ptr;
 
 #if !defined(PNG_NO_STDIO)
@@ -206,27 +206,27 @@ png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
 
 #if defined(USE_FAR_KEYWORD)
 #if defined(_MSC_VER)
-void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
+void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
 {
    void *near_ptr;
    void FAR *far_ptr;
    FP_OFF(near_ptr) = FP_OFF(ptr);
    far_ptr = (void FAR *)near_ptr;
-   if(check != 0)
-      if(FP_SEG(ptr) != FP_SEG(far_ptr))
-         png_error(png_ptr,"segment lost in conversion");
+   if (check != 0)
+      if (FP_SEG(ptr) != FP_SEG(far_ptr))
+         png_error(png_ptr, "segment lost in conversion");
    return(near_ptr);
 }
 #  else
-void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
+void *png_far_to_near(png_structp png_ptr, png_voidp ptr, int check)
 {
    void *near_ptr;
    void FAR *far_ptr;
    near_ptr = (void FAR *)ptr;
    far_ptr = (void FAR *)near_ptr;
-   if(check != 0)
-      if(far_ptr != ptr)
-         png_error(png_ptr,"segment lost in conversion");
+   if (check != 0)
+      if (far_ptr != ptr)
+         png_error(png_ptr, "segment lost in conversion");
    return(near_ptr);
 }
 #   endif
diff --git a/third_party/libpng/pngwrite.c b/third_party/libpng/pngwrite.c
index 7d02ad7..26ea2db 100644
--- a/third_party/libpng/pngwrite.c
+++ b/third_party/libpng/pngwrite.c
@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.2.27 [April 29, 2008]
+ * Last changed in libpng 1.2.31 [August 19, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -32,9 +32,9 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
    {
    png_write_sig(png_ptr); /* write PNG signature */
 #if defined(PNG_MNG_FEATURES_SUPPORTED)
-   if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
+   if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
    {
-      png_warning(png_ptr,"MNG features are not allowed in a PNG datastream");
+      png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
       png_ptr->mng_features_permitted=0;
    }
 #endif
@@ -393,6 +393,18 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
 
    /* write end of PNG file */
    png_write_IEND(png_ptr);
+   /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
+    * and restored again in libpng-1.2.30, may cause some applications that
+    * do not set png_ptr->output_flush_fn to crash.  If your application
+    * experiences a problem, please try building libpng with
+    * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
+    * png-mng-implement at lists.sf.net .  This kludge will be removed
+    * from libpng-1.4.0.
+    */
+#if defined(PNG_WRITE_FLUSH_SUPPORTED) && \
+    defined(PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED)
+   png_flush(png_ptr);
+#endif
 }
 
 #if defined(PNG_WRITE_tIME_SUPPORTED)
@@ -439,7 +451,10 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
    png_malloc_ptr malloc_fn, png_free_ptr free_fn)
 {
 #endif /* PNG_USER_MEM_SUPPORTED */
-   png_structp png_ptr;
+#ifdef PNG_SETJMP_SUPPORTED
+    volatile
+#endif
+    png_structp png_ptr;
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
    jmp_buf jmpbuf;
@@ -470,12 +485,12 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #endif
    {
       png_free(png_ptr, png_ptr->zbuf);
-      png_ptr->zbuf=NULL;
+       png_ptr->zbuf=NULL;
       png_destroy_struct(png_ptr);
       return (NULL);
    }
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
 #endif
 #endif
 
@@ -484,12 +499,12 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #endif /* PNG_USER_MEM_SUPPORTED */
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
-   if(user_png_ver)
+   if (user_png_ver)
    {
      i=0;
      do
      {
-       if(user_png_ver[i] != png_libpng_ver[i])
+       if (user_png_ver[i] != png_libpng_ver[i])
           png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
      } while (png_libpng_ver[i++]);
    }
@@ -547,7 +562,7 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
       PNG_ABORT();
-   png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, jmpbuf, png_sizeof(jmp_buf));
 #else
    if (setjmp(png_ptr->jmpbuf))
       PNG_ABORT();
@@ -572,9 +587,9 @@ png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
    png_size_t png_struct_size, png_size_t png_info_size)
 {
    /* We only come here via pre-1.0.12-compiled applications */
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
-   if(png_sizeof(png_struct) > png_struct_size ||
+   if (png_sizeof(png_struct) > png_struct_size ||
       png_sizeof(png_info) > png_info_size)
    {
       char msg[80];
@@ -592,7 +607,7 @@ png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
       png_warning(png_ptr, msg);
    }
 #endif
-   if(png_sizeof(png_struct) > png_struct_size)
+   if (png_sizeof(png_struct) > png_struct_size)
      {
        png_ptr->error_fn=NULL;
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
@@ -601,7 +616,7 @@ png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
        png_error(png_ptr,
        "The png struct allocated by the application for writing is too small.");
      }
-   if(png_sizeof(png_info) > png_info_size)
+   if (png_sizeof(png_info) > png_info_size)
      {
        png_ptr->error_fn=NULL;
 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
@@ -638,7 +653,7 @@ png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 #else
        png_ptr->warning_fn=NULL;
        png_warning(png_ptr,
-     "Application uses deprecated png_write_init() and should be recompiled.");
+ "Application uses deprecated png_write_init() and should be recompiled.");
        break;
 #endif
      }
@@ -648,7 +663,7 @@ png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* save jump buffer and error functions */
-   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 #endif
 
    if (png_sizeof(png_struct) > png_struct_size)
@@ -659,7 +674,7 @@ png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
      }
 
    /* reset all variables to 0 */
-   png_memset(png_ptr, 0, png_sizeof (png_struct));
+   png_memset(png_ptr, 0, png_sizeof(png_struct));
 
    /* added at libpng-1.2.6 */
 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
@@ -669,7 +684,7 @@ png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* restore jump buffer */
-   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 
    png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
@@ -903,7 +918,7 @@ png_write_row(png_structp png_ptr, png_bytep row)
     * 4. The filter_method is 64 and
     * 5. The color_type is RGB or RGBA
     */
-   if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
       (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
    {
       /* Intrapixel differencing */
@@ -1027,7 +1042,7 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
         {
            png_free(png_ptr, png_ptr->chunk_list);
            png_ptr->chunk_list=NULL;
-           png_ptr->num_chunk_list=0;
+           png_ptr->num_chunk_list = 0;
         }
 #endif
       }
@@ -1076,7 +1091,7 @@ png_write_destroy(png_structp png_ptr)
    /* free our memory.  png_free checks NULL for us. */
    png_free(png_ptr, png_ptr->zbuf);
    png_free(png_ptr, png_ptr->row_buf);
-#ifndef PNG_NO_WRITE_FILTERING
+#ifndef PNG_NO_WRITE_FILTER
    png_free(png_ptr, png_ptr->prev_row);
    png_free(png_ptr, png_ptr->sub_row);
    png_free(png_ptr, png_ptr->up_row);
@@ -1098,7 +1113,7 @@ png_write_destroy(png_structp png_ptr)
 
 #ifdef PNG_SETJMP_SUPPORTED
    /* reset structure */
-   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
+   png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf));
 #endif
 
    error_fn = png_ptr->error_fn;
@@ -1108,7 +1123,7 @@ png_write_destroy(png_structp png_ptr)
    free_fn = png_ptr->free_fn;
 #endif
 
-   png_memset(png_ptr, 0, png_sizeof (png_struct));
+   png_memset(png_ptr, 0, png_sizeof(png_struct));
 
    png_ptr->error_fn = error_fn;
    png_ptr->warning_fn = warning_fn;
@@ -1118,7 +1133,7 @@ png_write_destroy(png_structp png_ptr)
 #endif
 
 #ifdef PNG_SETJMP_SUPPORTED
-   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
+   png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf));
 #endif
 }
 
@@ -1130,7 +1145,7 @@ png_set_filter(png_structp png_ptr, int method, int filters)
    if (png_ptr == NULL)
       return;
 #if defined(PNG_MNG_FEATURES_SUPPORTED)
-   if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
+   if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
       (method == PNG_INTRAPIXEL_DIFFERENCING))
          method = PNG_FILTER_TYPE_BASE;
 #endif
diff --git a/third_party/libpng/pngwtran.c b/third_party/libpng/pngwtran.c
index 0372fe6..e9374dc 100644
--- a/third_party/libpng/pngwtran.c
+++ b/third_party/libpng/pngwtran.c
@@ -25,7 +25,7 @@ png_do_write_transformations(png_structp png_ptr)
 
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
    if (png_ptr->transformations & PNG_USER_TRANSFORM)
-      if(png_ptr->write_user_transform_fn != NULL)
+      if (png_ptr->write_user_transform_fn != NULL)
         (*(png_ptr->write_user_transform_fn)) /* user write transform function */
           (png_ptr,                    /* png_ptr */
            &(png_ptr->row_info),       /* row_info:     */
@@ -558,8 +558,8 @@ png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
             png_uint_32 s0   = (*(rp  ) << 8) | *(rp+1);
             png_uint_32 s1   = (*(rp+2) << 8) | *(rp+3);
             png_uint_32 s2   = (*(rp+4) << 8) | *(rp+5);
-            png_uint_32 red  = (png_uint_32)((s0-s1) & 0xffffL);
-            png_uint_32 blue = (png_uint_32)((s2-s1) & 0xffffL);
+            png_uint_32 red  = (png_uint_32)((s0 - s1) & 0xffffL);
+            png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
             *(rp  ) = (png_byte)((red >> 8) & 0xff);
             *(rp+1) = (png_byte)(red & 0xff);
             *(rp+4) = (png_byte)((blue >> 8) & 0xff);
diff --git a/third_party/libpng/pngwutil.c b/third_party/libpng/pngwutil.c
index 0774080..3e060a6 100644
--- a/third_party/libpng/pngwutil.c
+++ b/third_party/libpng/pngwutil.c
@@ -1,7 +1,7 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * Last changed in libpng 1.2.27 [April 29, 2008]
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -49,6 +49,24 @@ png_save_uint_16(png_bytep buf, unsigned int i)
    buf[1] = (png_byte)(i & 0xff);
 }
 
+/* Simple function to write the signature.  If we have already written
+ * the magic bytes of the signature, or more likely, the PNG stream is
+ * being embedded into another stream and doesn't need its own signature,
+ * we should call png_set_sig_bytes() to tell libpng how many of the
+ * bytes have already been written.
+ */
+void /* PRIVATE */
+png_write_sig(png_structp png_ptr)
+{
+   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+
+   /* write the rest of the 8 byte signature */
+   png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
+      (png_size_t)(8 - png_ptr->sig_bytes));
+   if (png_ptr->sig_bytes < 3)
+      png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
+}
+
 /* Write a PNG chunk all at once.  The type is an array of ASCII characters
  * representing the chunk name.  The array must be at least 4 bytes in
  * length, and does not need to be null terminated.  To be safe, pass the
@@ -62,9 +80,9 @@ void PNGAPI
 png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
    png_bytep data, png_size_t length)
 {
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
-   png_write_chunk_data(png_ptr, data, length);
+   png_write_chunk_data(png_ptr, data, (png_size_t)length);
    png_write_chunk_end(png_ptr);
 }
 
@@ -76,16 +94,18 @@ void PNGAPI
 png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
    png_uint_32 length)
 {
-   png_byte buf[4];
-   png_debug2(0, "Writing %s chunk (%lu bytes)\n", chunk_name, length);
-   if(png_ptr == NULL) return;
+   png_byte buf[8];
 
-   /* write the length */
-   png_save_uint_32(buf, length);
-   png_write_data(png_ptr, buf, (png_size_t)4);
+   png_debug2(0, "Writing %s chunk, length = %lu\n", chunk_name,
+      (unsigned long)length);
+   if (png_ptr == NULL) return;
 
-   /* write the chunk name */
-   png_write_data(png_ptr, chunk_name, (png_size_t)4);
+   /* write the length and the chunk name */
+   png_save_uint_32(buf, length);
+   png_memcpy(buf + 4, chunk_name, 4);
+   png_write_data(png_ptr, buf, (png_size_t)8);
+   /* put the chunk name into png_ptr->chunk_name */
+   png_memcpy(png_ptr->chunk_name, chunk_name, 4);
    /* reset the crc and run it over the chunk name */
    png_reset_crc(png_ptr);
    png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
@@ -100,11 +120,14 @@ void PNGAPI
 png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
    /* write the data, and run the CRC over it */
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
    if (data != NULL && length > 0)
    {
-      png_calculate_crc(png_ptr, data, length);
       png_write_data(png_ptr, data, length);
+      /* update the CRC after writing the data,
+       * in case that the user I/O routine alters it.
+       */
+      png_calculate_crc(png_ptr, data, length);
    }
 }
 
@@ -114,31 +137,14 @@ png_write_chunk_end(png_structp png_ptr)
 {
    png_byte buf[4];
 
-   if(png_ptr == NULL) return;
+   if (png_ptr == NULL) return;
 
-   /* write the crc */
+   /* write the crc in a single operation */
    png_save_uint_32(buf, png_ptr->crc);
 
    png_write_data(png_ptr, buf, (png_size_t)4);
 }
 
-/* Simple function to write the signature.  If we have already written
- * the magic bytes of the signature, or more likely, the PNG stream is
- * being embedded into another stream and doesn't need its own signature,
- * we should call png_set_sig_bytes() to tell libpng how many of the
- * bytes have already been written.
- */
-void /* PRIVATE */
-png_write_sig(png_structp png_ptr)
-{
-   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
-   /* write the rest of the 8 byte signature */
-   png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
-      (png_size_t)8 - png_ptr->sig_bytes);
-   if(png_ptr->sig_bytes < 3)
-      png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
-}
-
 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
 /*
  * This pair of functions encapsulates the operation of (a) compressing a
@@ -239,20 +245,21 @@ png_text_compress(png_structp png_ptr,
 
                old_ptr = comp->output_ptr;
                comp->output_ptr = (png_charpp)png_malloc(png_ptr,
-                  (png_uint_32)(comp->max_output_ptr *
-                  png_sizeof (png_charpp)));
+                  (png_uint_32)
+                  (comp->max_output_ptr * png_sizeof(png_charpp)));
                png_memcpy(comp->output_ptr, old_ptr, old_max
-                  * png_sizeof (png_charp));
+                  * png_sizeof(png_charp));
                png_free(png_ptr, old_ptr);
             }
             else
                comp->output_ptr = (png_charpp)png_malloc(png_ptr,
-                  (png_uint_32)(comp->max_output_ptr *
-                  png_sizeof (png_charp)));
+                  (png_uint_32)
+                  (comp->max_output_ptr * png_sizeof(png_charp)));
          }
 
          /* save the data */
-         comp->output_ptr[comp->num_output_ptr] = (png_charp)png_malloc(png_ptr,
+         comp->output_ptr[comp->num_output_ptr] =
+            (png_charp)png_malloc(png_ptr,
             (png_uint_32)png_ptr->zbuf_size);
          png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
             png_ptr->zbuf_size);
@@ -291,20 +298,21 @@ png_text_compress(png_structp png_ptr,
                   /* This could be optimized to realloc() */
                   comp->output_ptr = (png_charpp)png_malloc(png_ptr,
                      (png_uint_32)(comp->max_output_ptr *
-                     png_sizeof (png_charpp)));
+                     png_sizeof(png_charp)));
                   png_memcpy(comp->output_ptr, old_ptr,
-                     old_max * png_sizeof (png_charp));
+                     old_max * png_sizeof(png_charp));
                   png_free(png_ptr, old_ptr);
                }
                else
                   comp->output_ptr = (png_charpp)png_malloc(png_ptr,
                      (png_uint_32)(comp->max_output_ptr *
-                     png_sizeof (png_charp)));
+                     png_sizeof(png_charp)));
             }
 
             /* save off the data */
             comp->output_ptr[comp->num_output_ptr] =
-               (png_charp)png_malloc(png_ptr, (png_uint_32)png_ptr->zbuf_size);
+               (png_charp)png_malloc(png_ptr,
+               (png_uint_32)png_ptr->zbuf_size);
             png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
                png_ptr->zbuf_size);
             comp->num_output_ptr++;
@@ -349,18 +357,18 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
    /* write saved output buffers, if any */
    for (i = 0; i < comp->num_output_ptr; i++)
    {
-      png_write_chunk_data(png_ptr,(png_bytep)comp->output_ptr[i],
-         png_ptr->zbuf_size);
+      png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],
+         (png_size_t)png_ptr->zbuf_size);
       png_free(png_ptr, comp->output_ptr[i]);
-      comp->output_ptr[i]=NULL;
+       comp->output_ptr[i]=NULL;
    }
    if (comp->max_output_ptr != 0)
       png_free(png_ptr, comp->output_ptr);
-      comp->output_ptr=NULL;
+       comp->output_ptr=NULL;
    /* write anything left in zbuf */
    if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
       png_write_chunk_data(png_ptr, png_ptr->zbuf,
-         png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+         (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
 
    /* reset zlib for another zTXt/iTXt or image data */
    deflateReset(&png_ptr->zstream);
@@ -396,7 +404,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
             case 4:
             case 8:
             case 16: png_ptr->channels = 1; break;
-            default: png_error(png_ptr,"Invalid bit depth for grayscale image");
+            default: png_error(png_ptr, "Invalid bit depth for grayscale image");
          }
          break;
       case PNG_COLOR_TYPE_RGB:
@@ -496,7 +504,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
    buf[12] = (png_byte)interlace_type;
 
    /* write the chunk */
-   png_write_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
+   png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
 
    /* initialize zlib with PNG info */
    png_ptr->zstream.zalloc = png_zalloc;
@@ -589,7 +597,8 @@ png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
    png_ptr->num_palette = (png_uint_16)num_pal;
    png_debug1(3, "num_palette = %d\n", png_ptr->num_palette);
 
-   png_write_chunk_start(png_ptr, png_PLTE, num_pal * 3);
+   png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,
+     (png_uint_32)(num_pal * 3));
 #ifndef PNG_NO_POINTER_INDEXING
    for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
    {
@@ -661,7 +670,7 @@ png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
             "Invalid zlib compression method or flags in IDAT");
    }
 
-   png_write_chunk(png_ptr, png_IDAT, data, length);
+   png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
    png_ptr->mode |= PNG_HAVE_IDAT;
 }
 
@@ -673,7 +682,7 @@ png_write_IEND(png_structp png_ptr)
    PNG_IEND;
 #endif
    png_debug(1, "in png_write_IEND\n");
-   png_write_chunk(png_ptr, png_IEND, png_bytep_NULL,
+   png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
      (png_size_t)0);
    png_ptr->mode |= PNG_HAVE_IEND;
 }
@@ -694,7 +703,7 @@ png_write_gAMA(png_structp png_ptr, double file_gamma)
    /* file_gamma is saved in 1/100,000ths */
    igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
    png_save_uint_32(buf, igamma);
-   png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
+   png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
 }
 #endif
 #ifdef PNG_FIXED_POINT_SUPPORTED
@@ -709,7 +718,7 @@ png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
    png_debug(1, "in png_write_gAMA\n");
    /* file_gamma is saved in 1/100,000ths */
    png_save_uint_32(buf, (png_uint_32)file_gamma);
-   png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
+   png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
 }
 #endif
 #endif
@@ -725,11 +734,11 @@ png_write_sRGB(png_structp png_ptr, int srgb_intent)
    png_byte buf[1];
 
    png_debug(1, "in png_write_sRGB\n");
-   if(srgb_intent >= PNG_sRGB_INTENT_LAST)
+   if (srgb_intent >= PNG_sRGB_INTENT_LAST)
          png_warning(png_ptr,
             "Invalid sRGB rendering intent specified");
    buf[0]=(png_byte)srgb_intent;
-   png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
+   png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
 }
 #endif
 
@@ -770,34 +779,35 @@ png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
 
    if (profile_len > 3)
       embedded_profile_len =
-          ((*( (png_bytep)profile  ))<<24) |
-          ((*( (png_bytep)profile+1))<<16) |
-          ((*( (png_bytep)profile+2))<< 8) |
-          ((*( (png_bytep)profile+3))    );
+          ((*( (png_bytep)profile    ))<<24) |
+          ((*( (png_bytep)profile + 1))<<16) |
+          ((*( (png_bytep)profile + 2))<< 8) |
+          ((*( (png_bytep)profile + 3))    );
 
    if (profile_len < embedded_profile_len)
-     {
-        png_warning(png_ptr,
-          "Embedded profile length too large in iCCP chunk");
-        return;
-     }
+   {
+      png_warning(png_ptr,
+        "Embedded profile length too large in iCCP chunk");
+      return;
+   }
 
    if (profile_len > embedded_profile_len)
-     {
-        png_warning(png_ptr,
-          "Truncating profile to actual length in iCCP chunk");
-        profile_len = embedded_profile_len;
-     }
+   {
+      png_warning(png_ptr,
+        "Truncating profile to actual length in iCCP chunk");
+      profile_len = embedded_profile_len;
+   }
 
    if (profile_len)
-       profile_len = png_text_compress(png_ptr, profile, (png_size_t)profile_len,
-          PNG_COMPRESSION_TYPE_BASE, &comp);
+      profile_len = png_text_compress(png_ptr, profile,
+        (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
 
    /* make sure we include the NULL after the name and the compression type */
-   png_write_chunk_start(png_ptr, png_iCCP,
-          (png_uint_32)name_len+profile_len+2);
-   new_name[name_len+1]=0x00;
-   png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 2);
+   png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
+          (png_uint_32)(name_len + profile_len + 2));
+   new_name[name_len + 1] = 0x00;
+   png_write_chunk_data(png_ptr, (png_bytep)new_name,
+     (png_size_t)(name_len + 2));
 
    if (profile_len)
       png_write_compressed_data_out(png_ptr, &comp);
@@ -834,54 +844,55 @@ png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
    }
 
    /* make sure we include the NULL after the name */
-   png_write_chunk_start(png_ptr, png_sPLT,
-          (png_uint_32)(name_len + 2 + palette_size));
-   png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 1);
-   png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, 1);
+   png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
+     (png_uint_32)(name_len + 2 + palette_size));
+   png_write_chunk_data(png_ptr, (png_bytep)new_name,
+     (png_size_t)(name_len + 1));
+   png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, (png_size_t)1);
 
    /* loop through each palette entry, writing appropriately */
 #ifndef PNG_NO_POINTER_INDEXING
-   for (ep = spalette->entries; ep<spalette->entries+spalette->nentries; ep++)
-   {
-       if (spalette->depth == 8)
-       {
-           entrybuf[0] = (png_byte)ep->red;
-           entrybuf[1] = (png_byte)ep->green;
-           entrybuf[2] = (png_byte)ep->blue;
-           entrybuf[3] = (png_byte)ep->alpha;
-           png_save_uint_16(entrybuf + 4, ep->frequency);
-       }
-       else
-       {
-           png_save_uint_16(entrybuf + 0, ep->red);
-           png_save_uint_16(entrybuf + 2, ep->green);
-           png_save_uint_16(entrybuf + 4, ep->blue);
-           png_save_uint_16(entrybuf + 6, ep->alpha);
-           png_save_uint_16(entrybuf + 8, ep->frequency);
-       }
-       png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
+   for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
+   {
+      if (spalette->depth == 8)
+      {
+          entrybuf[0] = (png_byte)ep->red;
+          entrybuf[1] = (png_byte)ep->green;
+          entrybuf[2] = (png_byte)ep->blue;
+          entrybuf[3] = (png_byte)ep->alpha;
+          png_save_uint_16(entrybuf + 4, ep->frequency);
+      }
+      else
+      {
+          png_save_uint_16(entrybuf + 0, ep->red);
+          png_save_uint_16(entrybuf + 2, ep->green);
+          png_save_uint_16(entrybuf + 4, ep->blue);
+          png_save_uint_16(entrybuf + 6, ep->alpha);
+          png_save_uint_16(entrybuf + 8, ep->frequency);
+      }
+      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
    }
 #else
    ep=spalette->entries;
    for (i=0; i>spalette->nentries; i++)
    {
-       if (spalette->depth == 8)
-       {
-           entrybuf[0] = (png_byte)ep[i].red;
-           entrybuf[1] = (png_byte)ep[i].green;
-           entrybuf[2] = (png_byte)ep[i].blue;
-           entrybuf[3] = (png_byte)ep[i].alpha;
-           png_save_uint_16(entrybuf + 4, ep[i].frequency);
-       }
-       else
-       {
-           png_save_uint_16(entrybuf + 0, ep[i].red);
-           png_save_uint_16(entrybuf + 2, ep[i].green);
-           png_save_uint_16(entrybuf + 4, ep[i].blue);
-           png_save_uint_16(entrybuf + 6, ep[i].alpha);
-           png_save_uint_16(entrybuf + 8, ep[i].frequency);
-       }
-       png_write_chunk_data(png_ptr, entrybuf, entry_size);
+      if (spalette->depth == 8)
+      {
+          entrybuf[0] = (png_byte)ep[i].red;
+          entrybuf[1] = (png_byte)ep[i].green;
+          entrybuf[2] = (png_byte)ep[i].blue;
+          entrybuf[3] = (png_byte)ep[i].alpha;
+          png_save_uint_16(entrybuf + 4, ep[i].frequency);
+      }
+      else
+      {
+          png_save_uint_16(entrybuf + 0, ep[i].red);
+          png_save_uint_16(entrybuf + 2, ep[i].green);
+          png_save_uint_16(entrybuf + 4, ep[i].blue);
+          png_save_uint_16(entrybuf + 6, ep[i].alpha);
+          png_save_uint_16(entrybuf + 8, ep[i].frequency);
+      }
+      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
    }
 #endif
 
@@ -942,7 +953,7 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
       buf[size++] = sbit->alpha;
    }
 
-   png_write_chunk(png_ptr, png_sBIT, buf, size);
+   png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
 }
 #endif
 
@@ -967,7 +978,7 @@ png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
    {
       png_warning(png_ptr, "Invalid cHRM white point specified");
 #if !defined(PNG_NO_CONSOLE_IO)
-      fprintf(stderr,"white_x=%f, white_y=%f\n",white_x, white_y);
+      fprintf(stderr, "white_x=%f, white_y=%f\n", white_x, white_y);
 #endif
       return;
    }
@@ -1006,7 +1017,7 @@ png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
    itemp = (png_uint_32)(blue_y * 100000.0 + 0.5);
    png_save_uint_32(buf + 28, itemp);
 
-   png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32);
+   png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
 }
 #endif
 #ifdef PNG_FIXED_POINT_SUPPORTED
@@ -1027,7 +1038,8 @@ png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
    {
       png_warning(png_ptr, "Invalid fixed cHRM white point specified");
 #if !defined(PNG_NO_CONSOLE_IO)
-      fprintf(stderr,"white_x=%ld, white_y=%ld\n",white_x, white_y);
+      fprintf(stderr, "white_x=%ld, white_y=%ld\n", (unsigned long)white_x,
+        (unsigned long)white_y);
 #endif
       return;
    }
@@ -1058,7 +1070,7 @@ png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
    png_save_uint_32(buf + 24, (png_uint_32)blue_x);
    png_save_uint_32(buf + 28, (png_uint_32)blue_y);
 
-   png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32);
+   png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
 }
 #endif
 #endif
@@ -1079,23 +1091,24 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
    {
       if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
       {
-         png_warning(png_ptr,"Invalid number of transparent colors specified");
+         png_warning(png_ptr, "Invalid number of transparent colors specified");
          return;
       }
       /* write the chunk out as it is */
-      png_write_chunk(png_ptr, png_tRNS, trans, (png_size_t)num_trans);
+      png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans,
+        (png_size_t)num_trans);
    }
    else if (color_type == PNG_COLOR_TYPE_GRAY)
    {
       /* one 16 bit value */
-      if(tran->gray >= (1 << png_ptr->bit_depth))
+      if (tran->gray >= (1 << png_ptr->bit_depth))
       {
          png_warning(png_ptr,
            "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
          return;
       }
       png_save_uint_16(buf, tran->gray);
-      png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
+      png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
    }
    else if (color_type == PNG_COLOR_TYPE_RGB)
    {
@@ -1103,13 +1116,13 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
       png_save_uint_16(buf, tran->red);
       png_save_uint_16(buf + 2, tran->green);
       png_save_uint_16(buf + 4, tran->blue);
-      if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
-         {
-            png_warning(png_ptr,
-              "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
-            return;
-         }
-      png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
+      if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+      {
+         png_warning(png_ptr,
+           "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
+         return;
+      }
+      png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
    }
    else
    {
@@ -1142,31 +1155,31 @@ png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
          return;
       }
       buf[0] = back->index;
-      png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
+      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
    }
    else if (color_type & PNG_COLOR_MASK_COLOR)
    {
       png_save_uint_16(buf, back->red);
       png_save_uint_16(buf + 2, back->green);
       png_save_uint_16(buf + 4, back->blue);
-      if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
-         {
-            png_warning(png_ptr,
-              "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
-            return;
-         }
-      png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
+      if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+      {
+         png_warning(png_ptr,
+           "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+         return;
+      }
+      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
    }
    else
    {
-      if(back->gray >= (1 << png_ptr->bit_depth))
+      if (back->gray >= (1 << png_ptr->bit_depth))
       {
          png_warning(png_ptr,
            "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
          return;
       }
       png_save_uint_16(buf, back->gray);
-      png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
+      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
    }
 }
 #endif
@@ -1191,7 +1204,8 @@ png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
       return;
    }
 
-   png_write_chunk_start(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
+   png_write_chunk_start(png_ptr, (png_bytep)png_hIST,
+     (png_uint_32)(num_hist * 2));
    for (i = 0; i < num_hist; i++)
    {
       png_save_uint_16(buf, hist[i]);
@@ -1311,13 +1325,13 @@ png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
       }
    }
    *dp = '\0';
-   if(kwarn)
+   if (kwarn)
       png_warning(png_ptr, "extra interior spaces removed from keyword");
 
    if (key_len == 0)
    {
       png_free(png_ptr, *new_key);
-      *new_key=NULL;
+       *new_key=NULL;
       png_warning(png_ptr, "Zero length keyword");
    }
 
@@ -1357,16 +1371,18 @@ png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
       text_len = png_strlen(text);
 
    /* make sure we include the 0 after the key */
-   png_write_chunk_start(png_ptr, png_tEXt, (png_uint_32)key_len+text_len+1);
+   png_write_chunk_start(png_ptr, (png_bytep)png_tEXt,
+      (png_uint_32)(key_len + text_len + 1));
    /*
     * We leave it to the application to meet PNG-1.0 requirements on the
     * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
     * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
     * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
     */
-   png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
+   png_write_chunk_data(png_ptr, (png_bytep)new_key,
+     (png_size_t)(key_len + 1));
    if (text_len)
-      png_write_chunk_data(png_ptr, (png_bytep)text, text_len);
+      png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len);
 
    png_write_chunk_end(png_ptr);
    png_free(png_ptr, new_key);
@@ -1398,6 +1414,7 @@ png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
    if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
    {
       png_warning(png_ptr, "Empty keyword in zTXt chunk");
+      png_free(png_ptr, new_key);
       return;
    }
 
@@ -1415,10 +1432,11 @@ png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
        &comp);
 
    /* write start of chunk */
-   png_write_chunk_start(png_ptr, png_zTXt, (png_uint_32)
-      (key_len+text_len+2));
+   png_write_chunk_start(png_ptr, (png_bytep)png_zTXt,
+     (png_uint_32)(key_len+text_len + 2));
    /* write key */
-   png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
+   png_write_chunk_data(png_ptr, (png_bytep)new_key,
+     (png_size_t)(key_len + 1));
    png_free(png_ptr, new_key);
 
    buf[0] = (png_byte)compression;
@@ -1483,7 +1501,7 @@ png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
    /* make sure we include the compression flag, the compression byte,
     * and the NULs after the key, lang, and lang_key parts */
 
-   png_write_chunk_start(png_ptr, png_iTXt,
+   png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
           (png_uint_32)(
         5 /* comp byte, comp flag, terminators for key, lang and lang_key */
         + key_len
@@ -1497,7 +1515,8 @@ png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
     * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
     * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
     */
-   png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
+   png_write_chunk_data(png_ptr, (png_bytep)new_key,
+     (png_size_t)(key_len + 1));
 
    /* set the compression flag */
    if (compression == PNG_ITXT_COMPRESSION_NONE || \
@@ -1507,11 +1526,13 @@ png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
        cbuf[0] = 1;
    /* set the compression method */
    cbuf[1] = 0;
-   png_write_chunk_data(png_ptr, cbuf, 2);
+   png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
 
    cbuf[0] = 0;
-   png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf), lang_len + 1);
-   png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf), lang_key_len + 1);
+   png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf),
+     (png_size_t)(lang_len + 1));
+   png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf),
+     (png_size_t)(lang_key_len + 1));
    png_write_compressed_data_out(png_ptr, &comp);
 
    png_write_chunk_end(png_ptr);
@@ -1539,7 +1560,7 @@ png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
    png_save_int_32(buf + 4, y_offset);
    buf[8] = (png_byte)unit_type;
 
-   png_write_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
+   png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
 }
 #endif
 #if defined(PNG_WRITE_pCAL_SUPPORTED)
@@ -1567,21 +1588,23 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
    png_debug1(3, "pCAL units length = %d\n", (int)units_len);
    total_len = purpose_len + units_len + 10;
 
-   params_len = (png_uint_32p)png_malloc(png_ptr, (png_uint_32)(nparams
-      *png_sizeof(png_uint_32)));
+   params_len = (png_uint_32p)png_malloc(png_ptr,
+      (png_uint_32)(nparams * png_sizeof(png_uint_32)));
 
    /* Find the length of each parameter, making sure we don't count the
       null terminator for the last parameter. */
    for (i = 0; i < nparams; i++)
    {
       params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
-      png_debug2(3, "pCAL parameter %d length = %lu\n", i, params_len[i]);
+      png_debug2(3, "pCAL parameter %d length = %lu\n", i,
+        (unsigned long) params_len[i]);
       total_len += (png_size_t)params_len[i];
    }
 
    png_debug1(3, "pCAL total length = %d\n", (int)total_len);
-   png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len);
-   png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len);
+   png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
+   png_write_chunk_data(png_ptr, (png_bytep)new_purpose,
+     (png_size_t)purpose_len);
    png_save_int_32(buf, X0);
    png_save_int_32(buf + 4, X1);
    buf[8] = (png_byte)type;
@@ -1640,7 +1663,7 @@ png_write_sCAL(png_structp png_ptr, int unit, double width, double height)
 #endif
 
    png_debug1(3, "sCAL total length = %u\n", (unsigned int)total_len);
-   png_write_chunk(png_ptr, png_sCAL, (png_bytep)buf, total_len);
+   png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len);
 }
 #else
 #ifdef PNG_FIXED_POINT_SUPPORTED
@@ -1670,7 +1693,7 @@ png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
    png_memcpy(buf + wlen + 2, height, hlen);  /* do NOT append the '\0' here */
 
    png_debug1(3, "sCAL total length = %u\n", (unsigned int)total_len);
-   png_write_chunk(png_ptr, png_sCAL, buf, total_len);
+   png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len);
 }
 #endif
 #endif
@@ -1696,7 +1719,7 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
    png_save_uint_32(buf + 4, y_pixels_per_unit);
    buf[8] = (png_byte)unit_type;
 
-   png_write_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
+   png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
 }
 #endif
 
@@ -1728,7 +1751,7 @@ png_write_tIME(png_structp png_ptr, png_timep mod_time)
    buf[5] = mod_time->minute;
    buf[6] = mod_time->second;
 
-   png_write_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
+   png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
 }
 #endif
 
@@ -1758,18 +1781,19 @@ png_write_start_row(png_structp png_ptr)
 
    png_debug(1, "in png_write_start_row\n");
    buf_size = (png_size_t)(PNG_ROWBYTES(
-      png_ptr->usr_channels*png_ptr->usr_bit_depth,png_ptr->width)+1);
+      png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
 
    /* set up row buffer */
-   png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
+   png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
+     (png_uint_32)buf_size);
    png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
 
-#ifndef PNG_NO_WRITE_FILTERING
+#ifndef PNG_NO_WRITE_FILTER
    /* set up filtering buffer, if using this filter */
    if (png_ptr->do_filter & PNG_FILTER_SUB)
    {
       png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
-         (png_ptr->rowbytes + 1));
+         (png_uint_32)(png_ptr->rowbytes + 1));
       png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
    }
 
@@ -1777,31 +1801,32 @@ png_write_start_row(png_structp png_ptr)
    if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
    {
      /* set up previous row buffer */
-      png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
+      png_ptr->prev_row = (png_bytep)png_malloc(png_ptr,
+        (png_uint_32)buf_size);
       png_memset(png_ptr->prev_row, 0, buf_size);
 
       if (png_ptr->do_filter & PNG_FILTER_UP)
       {
          png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
-            (png_ptr->rowbytes + 1));
+           (png_uint_32)(png_ptr->rowbytes + 1));
          png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
       }
 
       if (png_ptr->do_filter & PNG_FILTER_AVG)
       {
          png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
-            (png_ptr->rowbytes + 1));
+           (png_uint_32)(png_ptr->rowbytes + 1));
          png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
       }
 
       if (png_ptr->do_filter & PNG_FILTER_PAETH)
       {
          png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
-            (png_ptr->rowbytes + 1));
+           (png_uint_32)(png_ptr->rowbytes + 1));
          png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
       }
-#endif /* PNG_NO_WRITE_FILTERING */
    }
+#endif /* PNG_NO_WRITE_FILTER */
 
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
    /* if interlaced, we need to set up width and height of pass */
@@ -1899,7 +1924,7 @@ png_write_finish_row(png_structp png_ptr)
          if (png_ptr->prev_row != NULL)
             png_memset(png_ptr->prev_row, 0,
                (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
-               png_ptr->usr_bit_depth,png_ptr->width))+1);
+               png_ptr->usr_bit_depth, png_ptr->width)) + 1);
          return;
       }
    }