Updated the bundled libpng to v1.2.33.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6592 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

29 files changed, 2042 insertions, 600 deletions

diff --git a/CHANGES b/CHANGES
index 4621abeec..b24d6b6cf 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,5 +1,6 @@
 CHANGES IN FLTK 1.3.0
 
+	- Updated the bundled libpng to v1.2.33.
 	- Fixed callback would not be called when shortcut was used with
           radio and toggle buttons in default FL_RELEASE mode.
 	- Fixed a problem with TrackMouseEvent() (Windows only) that would
diff --git a/png/ANNOUNCE b/png/ANNOUNCE
index afa31b928..af8e0c960 100644
--- a/png/ANNOUNCE
+++ b/png/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.2.25 - February 18, 2008
+Libpng 1.2.33 - October 31, 2008
 
 This is a public release of libpng, intended for use in production codes.
 
@@ -8,59 +8,47 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   libpng-1.2.25.tar.gz
-   libpng-1.2.25.tar.lzma
+   libpng-1.2.33.tar.gz
+   libpng-1.2.33.tar.lzma
      (Get the lzma codec from <http://tukaani.org/lzma>).
-   libpng-1.2.25.tar.bz2
+   libpng-1.2.33.tar.bz2
 
 Source files with LF line endings (for Unix/Linux) without the
 "configure" script
 
-   libpng-1.2.25-no-config.tar.gz
-   libpng-1.2.25-no-config.tar.lzma
-   libpng-1.2.25-no-config.tar.bz2
+   libpng-1.2.33-no-config.tar.gz
+   libpng-1.2.33-no-config.tar.lzma
+   libpng-1.2.33-no-config.tar.bz2
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lpng1225.zip
-   lpng1225.7z
-   lpng1225.tar.bz2
+   lpng1233.zip
+   lpng1233.7z
+   lpng1233.tar.bz2
 
 Project files
 
-   libpng-1.2.25-project-netware.zip
-   libpng-1.2.25-project-wince.zip
+   libpng-1.2.33-project-netware.zip
+   libpng-1.2.33-project-wince.zip
 
 Other information:
 
-   libpng-1.2.25-README.txt
-   libpng-1.2.25-KNOWNBUGS.txt
-   libpng-1.2.25-LICENSE.txt
-   libpng-1.2.25-Y2K-compliance.txt
-   libpng-1.2.25-1.2.24-diff.txt
-
-Changes since the last public release (1.2.24):
-
-version 1.2.25 [February 18, 2008]
-
-  Fixed bug with unknown chunk handling, introduced in version 1.2.17
-  Prevent gamma from being applied twice.
-  Fixed some continue-after-malloc-failure errors in pngset.c (David Hill)
-  Check for info_ptr == NULL in png_read_info() and png_process_data().
-  Check for possible use of NULL user_png_ver[] in png_create_read_struct().
-  Fix overflow of "msg" in png_decompres_chunk().
-  Added libpng-1.2.25.tar.lzma to distribution.  Get the lzma codec
-    from <http://tukaani.org/lzma>.
-  Added lpng1225.7z to distribution.  Get the 7-zip decoder from
-    from <http://www.7-zip.org>.
-  Fixed some broken links in the README file.
-  Refactored png_read_push_finish_row() slightly, trying to satisfy Coverity.
-  Fixed potential NULL dereference of png_ptr in png_destroy_write_struct();
-  clarified potential NULL dereference of png_ptr in png_destroy_read_struct();
-  fixed potential NULL dereference of info_ptr in png_handle_bKGD();
-  fixed potential NULL dereference of user_png_ver[] in
-    png_create_write_struct_2(). (Coverity)
+   libpng-1.2.33-README.txt
+   libpng-1.2.33-KNOWNBUGS.txt
+   libpng-1.2.33-LICENSE.txt
+   libpng-1.2.33-Y2K-compliance.txt
+   libpng-1.2.33-[previous version]-diff.txt
+
+Changes since the last public release (1.2.32):
+
+version 1.2.33 [October 31, 2008]
+
+  Revised makefile.darwin to fix shared library numbering.
+  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
+    in example.c (debian bug report)
+  Changed remaining "key" to "png_ptr->chunkdata" in png_handle_tEXt()
+    to avoid memory leak after memory failure while reading tEXt chunk.`
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit 
diff --git a/png/CHANGES b/png/CHANGES
index 7cee1a460..795107e77 100644
--- a/png/CHANGES
+++ b/png/CHANGES
@@ -2048,7 +2048,7 @@ version 1.2.25beta03 [January 22, 2008]
   Change "if (swidth == NULL)" to "if (sheight == NULL)" in png_handle_sCAL
     (bug introduced in libpng-1.2.4/1.0.13).
   Return from png_destroy_read_struct() if png_ptr_ptr is NULL.
-  Fix overflow of "msg" in png_decompres_chunk().
+  Fix overflow of "msg" in png_decompress_chunk().
 
 version 1.2.25beta04 [January 26, 2008]
   Work around Coverity bug report by slightly refactoring
@@ -2076,6 +2076,191 @@ version 1.2.25rc02 [February 10, 2008]
 version 1.2.25 and 1.0.31 [February 18, 2008]
   No changes.
 
+version 1.2.26beta01 [February 21, 2008]
+  Added missing "(" in pngmem.c.  Bug introduced in libpng-1.2.2/1.0.13
+
+version 1.2.26beta02 [March 12, 2008]
+  Refined error message returned from deflateInit2 in pngwutil.c
+  Check IHDR length in png_push_read_chunk() before saving it.
+
+version 1.2.26beta03 [March 16, 2008]
+  Revised contrib/gregbook to handle premature end-of-file and file
+    read errors correctly.
+
+version 1.2.26beta04 [March 18, 2008]
+  Free png_ptr->big_row_buf and png_ptr->prev_row before allocating
+    new copies in png_read_start_row().  Bug introduced in libpng-1.2.22.
+
+version 1.2.26beta05 [March 19, 2008]
+  Removed extra png_free() added in libpng-1.2.26beta04.
+
+version 1.2.26beta06 [March 19, 2008]
+  Avoid reallocating big_row_buf and prev_row when the size does not increase.
+
+version 1.2.26rc01 [March 26, 2008]
+  Ifdef out some code that is unused when interlacing is not supported.
+
+versions 1.0.32 and 1.2.26 [April 2, 2008]
+  No changes.
+
+version 1.2.27beta01 [April 12, 2008]
+  Fixed bug (introduced in libpng-1.0.5h) with handling zero-length
+    unknown chunks.
+  Added more information about png_set_keep_unknown_chunks() to the
+    documentation.
+  Reject tRNS chunk with out-of-range samples instead of masking off
+    the invalid high bits as done in since libpng-1.2.19beta5.
+
+version 1.2.27beta02 [April 13, 2008]
+  Revised documentation about unknown chunk and user chunk handling.
+  Keep tRNS chunk with out-of-range samples and issue a png_warning().
+
+version 1.2.27beta03 [April 14, 2008]
+  Added check for NULL ptr in TURBOC version of png_free_default().
+  Removed several unnecessary checks for NULL before calling png_free().
+  Revised png_set_tRNS() so that calling it twice removes and invalidates
+    the previous call.
+  Revised pngtest to check for out-of-range tRNS samples.
+
+version 1.2.27beta04 [April 18, 2008]
+  Added AC_LIBTOOL_WIN32_DLL to configure.ac
+  Rebuilt Makefile.in, aclocal.m4, and configure with autoconf-2.62
+
+version 1.2.27beta05 [April 19, 2008]
+  Added MAINTAINERCLEANFILES variable to Makefile.am
+
+version 1.2.27beta06 [April 21, 2008]
+  Avoid changing color_type from GRAY to RGB by
+    png_set_expand_gray_1_2_4_to_8().
+
+version 1.2.27rc01 [April 23, 2008]
+  Fix broken URL for rfc2083 in png.5 and libpng-*.txt
+
+version 1.0.33 and 1.2.27 [April 30, 2008]
+  No changes.
+
+version 1.0.34 and 1.2.28 [April 30, 2008]
+  Rebuilt Makefile.in, aclocal.m4, and configure with autoconf-2.61
+    due to backward incompatibilities.
+  Removed a stray object file from contrib/gregbook
+
+version 1.2.29beta01 [May 1, 2008]
+  Removed some stray *.diff and *.orig files
+
+version 1.2.29beta02 [May 1, 2008]
+  Reverted Makefile.in, aclocal.m4, and configure to the libpng-1.2.26
+    versions.
+
+version 1.2.29beta03 [May 2, 2008]
+  Added --force to autogen libtoolize options and --force-missing to
+    automake options.
+  Changed $(ECHO) to echo in Makefile.am and Makefile.in
+  Updated all configure files to autoconf-2.62
+  #ifdef out pnggcrd.c code if using MSC_VER
+
+version 1.2.29rc01 [May 4, 2008]
+  No changes.
+
+version 1.0.35 and 1.2.29 [May 8, 2008]
+  No changes.
+
+version 1.0.37 [May 9, 2008]
+  Updated Makefile.in and configure (omitted version 1.0.36).
+
+version 1.2.30beta01 [May 29, 2008]
+  Updated libpng.pc-configure.in and libpng-config.in per debian bug reports.
+
+version 1.2.30beta02 [June 25, 2008]
+  Restored png_flush(png_ptr) at the end of png_write_end(), that was
+    removed from libpng-1.0.9beta03.
+
+version 1.2.30beta03 [July 6, 2008]
+  Merged some cosmetic whitespace changes from libpng-1.4.0beta19.
+  Inline call of png_get_uint_32() in png_get_uint_31(), as in 1.4.0beta19.
+  Added demo of decoding vpAg and sTER chunks to pngtest.c, from 1.4.0beta19.
+  Changed PNGMAJ from 0 to 12 in makefile.darwin, which does not like 0.
+  Added new private function png_read_chunk_header() from 1.4.0beta19.
+  Merge reading of chunk length and chunk type into a single 8-byte read.
+  Merge writing of chunk length and chunk type into a single 8-byte write.
+
+version 1.2.30beta04 [July 10, 2008]
+  Merged more cosmetic whitespace changes from libpng-1.4.0beta19.
+
+version 1.0.38rc01, 1.2.30rc01 [October 31, 2008]
+  No changes.
+
+version 1.0.38rc02, 1.2.30rc02 [July 21, 2008]
+  Moved local array "chunkdata" from pngrutil.c to the png_struct, so
+    it will be freed by png_read_destroy() in case of a read error (Kurt
+    Christensen).
+
+version 1.0.38rc03, 1.2.30rc03 [July 21, 2008]
+  Changed "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.
+
+version 1.0.38rc04, 1.2.30rc04 [July 22, 2008]
+  Changed "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
+    png_decompress_chunk().
+
+version 1.0.38rc05, 1.2.30rc05 [July 25, 2008]
+  Changed all remaining "chunkdata" to "png_ptr->chunkdata" in
+    png_decompress_chunk() and remove chunkdata from parameter list.
+  Put a call to png_check_chunk_name() in png_read_chunk_header().
+  Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
+  Removed two calls to png_check_chunk_name() occuring later in the process.
+
+version 1.0.38rc06, 1.2.30rc06 [July 29, 2008]
+  Added a call to png_check_chunk_name() in pngpread.c
+  Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte.
+
+version 1.0.38r07, 1.2.30r07 [August 2, 2008]
+  Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta)
+  Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings.
+  Added code in pngset.c to quiet compiler warnings.
+  Updated contrib/visupng/cexcept.h to version 2.0.1
+  Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c
+
+version 1.0.38r08, 1.2.30r08 [August 2, 2008]
+  Enclose "volatile" declarations in #ifdef PNG_SETJMP_SUPPORTED (Cosmin).
+
+version 1.0.38, 1.2.30 [August 14, 2008]
+  No changes.
+
+version 1.2.31rc01 [August 19, 2008]
+  Removed extra crc check at the end of png_handle_cHRM().  Bug introduced
+    in libpng-1.2.30beta03 (Heiko Nitzsche).
+
+version 1.2.31rc02 [August 19, 2008]
+  Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call.
+
+version 1.2.31rc03 [August 19, 2008]
+  Added PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED block, off by default, around
+    new png_flush().
+
+version 1.0.39, 1.2.31 [August 21, 2008]
+  No changes.
+
+version 1.2.32beta01 [September 6, 2008]
+  Shortened tIME_string to 29 bytes in pngtest.c (bug introduced in
+    libpng-1.2.22).
+  Fixed off-by-one error introduced in png_push_read_zTXt() function in
+    libpng-1.2.30beta04/pngpread.c (Harald van Dijk)
+  These bugs have been given the vulnerability id CVE-2008-3964.
+
+version 1.0.40, 1.2.32 [September 18, 2008]
+  No changes.
+
+version 1.2.33beta01 [October 6, 2008]
+  Revised makefile.darwin to fix shared library numbering.
+  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
+    in example.c (debian bug report)
+
+version 1.2.33rc01 [October 15, 2008]
+  No changes.
+
+version 1.0.41rc01, version 1.2.33rc02 [October 31, 2008]
+  Changed remaining "key" to "png_ptr->chunkdata" in png_handle_tEXt()
+    to avoid memory leak after memory failure while reading tEXt chunk.`
+
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
diff --git a/png/INSTALL b/png/INSTALL
index 3ab8f42f7..1ce5bdf20 100644
--- a/png/INSTALL
+++ b/png/INSTALL
@@ -1,5 +1,5 @@
 
-Installing libpng version 1.2.25 - February 18, 2008
+Installing libpng version 1.2.33 - October 31, 2008
 
 On Unix/Linux and similar systems, you can simply type
 
@@ -44,7 +44,7 @@ to have access to the zlib.h and zconf.h include files that
 correspond to the version of zlib that's installed.
 
 You can rename the directories that you downloaded (they
-might be called "libpng-1.2.25" or "lpng109" and "zlib-1.2.1"
+might be called "libpng-1.2.33" or "lpng109" and "zlib-1.2.1"
 or "zlib121") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
@@ -101,9 +101,9 @@ include
  CMakeLists.txt    =>  "cmake" script
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.elf      =>  Linux/ELF makefile symbol versioning,
-                       gcc, creates libpng12.so.0.1.2.25)
+                       gcc, creates libpng12.so.0.1.2.33)
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng12.so.0.1.2.25)
+                       (gcc, creates libpng12.so.0.1.2.33)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -125,14 +125,14 @@ include
  makefile.openbsd  =>  OpenBSD makefile
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng12.so.0.1.2.25)
+                       creates libpng12.so.0.1.2.33)
  makefile.sunos    =>  Sun makefile
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng12.so.0.1.2.25)
+                       creates libpng12.so.0.1.2.33)
  makefile.solaris-x86 =>  Solaris/intelMMX 2.X makefile (gcc,
-                       creates libpng12.so.0.1.2.25)
+                       creates libpng12.so.0.1.2.33)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng12.so.0.1.2.25)
+                       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
diff --git a/png/KNOWNBUG b/png/KNOWNBUG
index a2f8458ea..ac8764f41 100644
--- a/png/KNOWNBUG
+++ b/png/KNOWNBUG
@@ -1,5 +1,5 @@
 
-Known bugs in libpng version 1.2.25
+Known bugs in libpng version 1.2.33
 
 1. February 23, 2006: The custom makefiles don't build libpng with -lz.
 
diff --git a/png/LICENSE b/png/LICENSE
index 7f5c259be..ac395e8cc 100644
--- a/png/LICENSE
+++ b/png/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 1.2.25, February 18, 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
-February 18, 2008
+October 31, 2008
diff --git a/png/README b/png/README
index eb072aa52..df370be85 100644
--- a/png/README
+++ b/png/README
@@ -1,12 +1,15 @@
-README for libpng version 1.2.25 - February 18, 2008 (shared library 12.0)
+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 lpng*.zip if you want DOS-style
-line endings.
+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
@@ -55,7 +58,7 @@ to set different actions based on whether the CRC error occurred in a
 critical or an ancillary chunk.
 
 The changes made to the library, and bugs fixed are based on discussions
-on the PNG-implement mailing list
+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.
 
@@ -111,14 +114,14 @@ to subscribe) or to glennrp at users.sourceforge.net
 
 You can't reach Guy, the original libpng author, at the addresses
 given in previous versions of this document.  He and Andreas will read mail
-addressed to the png-implement list, however.
+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-implement list.  I'll
+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,
@@ -191,11 +194,11 @@ Files in this distribution:
        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.0.1.2.25)
+                            gcc, creates libpng12.so.0.1.2.33)
        makefile.linux   =>  Linux/ELF makefile
-                            (gcc, creates libpng12.so.0.1.2.25)
+                            (gcc, creates libpng12.so.0.1.2.33)
        makefile.gcmmx   =>  Linux/ELF makefile
-                            (gcc, creates libpng12.so.0.1.2.25,
+                            (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
@@ -217,12 +220,12 @@ Files in this distribution:
        makefile.openbsd =>  OpenBSD makefile
        makefile.sgi     =>  Silicon Graphics IRIX (cc, creates static lib)
        makefile.sggcc   =>  Silicon Graphics
-                            (gcc, creates libpng12.so.0.1.2.25)
+                            (gcc, creates libpng12.so.0.1.2.33)
        makefile.sunos   =>  Sun makefile
        makefile.solaris =>  Solaris 2.X makefile
-                            (gcc, creates libpng12.so.0.1.2.25)
+                            (gcc, creates libpng12.so.0.1.2.33)
        makefile.so9     =>  Solaris 9 makefile
-                            (gcc, creates libpng12.so.0.1.2.25)
+                            (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
diff --git a/png/Y2KINFO b/png/Y2KINFO
index 075599c0d..cd8615cc8 100644
--- a/png/Y2KINFO
+++ b/png/Y2KINFO
@@ -1,13 +1,13 @@
    Y2K compliance in libpng:
    =========================
 
-      February 18, 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 1.2.25 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
diff --git a/png/libpng.3 b/png/libpng.3
index ae397476e..fb71b859c 100644
--- a/png/libpng.3
+++ b/png/libpng.3
@@ -1,404 +1,815 @@
-.TH LIBPNG 3 "February 18, 2008"
+.TH LIBPNG 3 "October 31, 2008"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.2.25
+libpng \- Portable Network Graphics (PNG) Reference Library 1.2.33
 .SH SYNOPSIS
-\fB
-#include <png.h>\fP
+\fI\fB
+
+\fB#include <png.h>\fP
+
+\fI\fB
 
 \fBpng_uint_32 png_access_version_number \fI(void\fP\fB);\fP
 
+\fI\fB
+
 \fBint png_check_sig (png_bytep \fP\fIsig\fP\fB, int \fInum\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_chunk_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_chunk_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_convert_from_struct_tm (png_timep \fP\fIptime\fP\fB, struct tm FAR * \fIttime\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_convert_from_time_t (png_timep \fP\fIptime\fP\fB, time_t \fIttime\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_charp png_convert_to_rfc1123 (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fIptime\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_infop png_create_info_struct (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_structp png_create_read_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_structp png_create_read_struct_2(png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_structp png_create_write_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_structp png_create_write_struct_2(png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBint png_debug(int \fP\fIlevel\fP\fB, png_const_charp \fImessage\fP\fB);\fP
 
+\fI\fB
+
 \fBint png_debug1(int \fP\fIlevel\fP\fB, png_const_charp \fP\fImessage\fP\fB, \fIp1\fP\fB);\fP
 
+\fI\fB
+
 \fBint png_debug2(int \fP\fIlevel\fP\fB, png_const_charp \fP\fImessage\fP\fB, \fP\fIp1\fP\fB, \fIp2\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_destroy_info_struct (png_structp \fP\fIpng_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_destroy_read_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fP\fIinfo_ptr_ptr\fP\fB, png_infopp \fIend_info_ptr_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_destroy_write_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_free (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_free_chunk_list (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_free_default(png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_free_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fInum\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_bit_depth (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fI*background\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_channels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*white_x\fP\fB, double \fP\fI*white_y\fP\fB, double \fP\fI*red_x\fP\fB, double \fP\fI*red_y\fP\fB, double \fP\fI*green_x\fP\fB, double \fP\fI*green_y\fP\fB, double \fP\fI*blue_x\fP\fB, double \fI*blue_y\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*white_x\fP\fB, png_uint_32 \fP\fI*white_y\fP\fB, png_uint_32 \fP\fI*red_x\fP\fB, png_uint_32 \fP\fI*red_y\fP\fB, png_uint_32 \fP\fI*green_x\fP\fB, png_uint_32 \fP\fI*green_y\fP\fB, png_uint_32 \fP\fI*blue_x\fP\fB, png_uint_32 \fI*blue_y\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_color_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_compression_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_copyright (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_get_error_ptr (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_filter_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fI*file_gamma\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fI*int_file_gamma\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_header_ver (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_header_version (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fI*hist\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charpp \fP\fIname\fP\fB, int \fP\fI*compression_type\fP\fB, png_charpp \fP\fIprofile\fP\fB, png_uint_32 \fI*proflen\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*width\fP\fB, png_uint_32 \fP\fI*height\fP\fB, int \fP\fI*bit_depth\fP\fB, int \fP\fI*color_type\fP\fB, int \fP\fI*interlace_type\fP\fB, int \fP\fI*compression_type\fP\fB, int \fI*filter_type\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_image_height (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_image_width (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
-\fB#if !defined(PNG_1_0_X) png_int_32 png_get_int_32 (png_bytep buf); \fI#endif
+\fI\fB
+
+\fB#if \fI!defined(PNG_1_0_X)
+
+\fBpng_int_32 png_get_int_32 (png_bytep \fIbuf\fP\fB);\fP
+
+\fI\fB#endif
+
+\fI\fB
 
 \fBpng_byte png_get_interlace_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_get_io_ptr (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_byte png_get_libpng_ver (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_get_mem_ptr(png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*offset_x\fP\fB, png_uint_32 \fP\fI*offset_y\fP\fB, int \fI*unit_type\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fI*purpose\fP\fB, png_int_32 \fP\fI*X0\fP\fB, png_int_32 \fP\fI*X1\fP\fB, int \fP\fI*type\fP\fB, int \fP\fI*nparams\fP\fB, png_charp \fP\fI*units\fP\fB, png_charpp \fI*params\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP
 
+\fI\fB
+
 \fBfloat png_get_pixel_aspect_ratio (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_get_progressive_ptr (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fI*palette\fP\fB, int \fI*num_palette\fP\fB);\fP
 
-\fBpng_byte png_get_rgb_to_gray_status (png_structp png_ptr) png_uint_32 png_get_rowbytes (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fI\fB
+
+\fBpng_byte png_get_rgb_to_gray_status (png_structp \fIpng_ptr)
+
+\fBpng_uint_32 png_get_rowbytes (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
 
 \fBpng_bytepp png_get_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fI*sig_bit\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_bytep png_get_signature (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fI*splt_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fI*intent\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fI*text_ptr\fP\fB, int \fI*num_text\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fI*mod_time\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fI*trans\fP\fB, int \fP\fI*num_trans\fP\fB, png_color_16p \fI*trans_values\fP\fB);\fP
 
-\fB#if !defined(PNG_1_0_X) png_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP
+\fI\fB
+
+\fB#if \fI!defined(PNG_1_0_X)
+
+\fBpng_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP
+
+\fI\fB
 
 \fBpng_uint_32 png_get_uint_31 (png_bytep \fIbuf\fP\fB);\fP
 
-\fBpng_uint_32 png_get_uint_32 (png_bytep buf); \fI#endif
+\fI\fB
+
+\fBpng_uint_32 png_get_uint_32 (png_bytep \fIbuf\fP\fB);\fP
+
+\fI\fB#endif
+
+\fI\fB
 
 \fBpng_uint_32 png_get_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkpp \fIunknowns\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_get_user_chunk_ptr (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_user_height_max( png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_get_user_transform_ptr (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_user_width_max (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_valid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIflag\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_int_32 png_get_x_offset_microns (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_int_32 png_get_x_offset_pixels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_x_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_int_32 png_get_y_offset_microns (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_int_32 png_get_y_offset_pixels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_y_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_get_compression_buffer_size (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBint png_handle_as_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_init_io (png_structp \fP\fIpng_ptr\fP\fB, FILE \fI*fp\fP\fB);\fP
 
+\fI\fB
+
 \fBDEPRECATED: void png_info_init (png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBDEPRECATED: void png_info_init_2 (png_infopp \fP\fIptr_ptr\fP\fB, png_size_t \fIpng_info_struct_size\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_malloc (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_malloc_default(png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
 
+\fI\fB
+
 \fBvoidp png_memcpy (png_voidp \fP\fIs1\fP\fB, png_voidp \fP\fIs2\fP\fB, png_size_t \fIsize\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_memcpy_check (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIs1\fP\fB, png_voidp \fP\fIs2\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
 
+\fI\fB
+
 \fBvoidp png_memset (png_voidp \fP\fIs1\fP\fB, int \fP\fIvalue\fP\fB, png_size_t \fIsize\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_voidp png_memset_check (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIs1\fP\fB, int \fP\fIvalue\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
 
+\fI\fB
+
 \fBDEPRECATED: void png_permit_empty_plte (png_structp \fP\fIpng_ptr\fP\fB, int \fIempty_plte_permitted\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_size\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_progressive_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIold_row\fP\fB, png_bytep \fInew_row\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_read_destroy (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_infop \fIend_info_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_read_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP
 
+\fI\fB
+
 \fBDEPRECATED: void png_read_init (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBDEPRECATED: void png_read_init_2 (png_structpp \fP\fIptr_ptr\fP\fB, png_const_charp \fP\fIuser_png_ver\fP\fB, png_size_t \fP\fIpng_struct_size\fP\fB, png_size_t \fIpng_info_size\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_read_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_read_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_read_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fIdisplay_row\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_read_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_bytepp \fP\fIdisplay_row\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_read_update_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
-\fB#if !defined(PNG_1_0_X) png_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP
+\fI\fB
+
+\fB#if \fI!defined(PNG_1_0_X)
+
+\fBpng_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP
+
+\fI\fB
 
 \fBvoid png_save_uint_16 (png_bytep \fP\fIbuf\fP\fB, unsigned int \fIi\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_save_uint_32 (png_bytep \fP\fIbuf\fP\fB, png_uint_32 \fIi\fP\fB);\fP
 
-\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int flags); \fI#endif
+\fI\fB
+
+\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
+
+\fI\fB#endif
+
+\fI\fB
 
 \fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_bgr (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \fIblue_y\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_crc_action (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcrit_action\fP\fB, int \fIancil_action\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_dither (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fP\fInum_palette\fP\fB, int \fP\fImaximum_colors\fP\fB, png_uint_16p \fP\fIhistogram\fP\fB, int \fIfull_dither\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_error_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarning_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_expand (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_expand_gray_1_2_4_to_8(png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_filler (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_filter (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImethod\fP\fB, int \fIfilters\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_filter_heuristics (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_doublep \fP\fIfilter_weights\fP\fB, png_doublep \fIfilter_costs\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_flush (png_structp \fP\fIpng_ptr\fP\fB, int \fInrows\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_gamma (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIscreen_gamma\fP\fB, double \fIdefault_file_gamma\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIfile_gamma\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_gray_1_2_4_to_8(png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_gray_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fIhist\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_charp \fP\fIprofile\fP\fB, png_uint_32 \fIproflen\fP\fB);\fP
 
+\fI\fB
+
 \fBint png_set_interlace_handling (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_invalid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fImask\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_invert_alpha (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_invert_mono (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIinterlace_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fIfilter_type\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_keep_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIkeep\fP\fB, png_bytep \fP\fIchunk_list\fP\fB, int \fInum_chunks\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_mem_fn(png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIoffset_x\fP\fB, png_uint_32 \fP\fIoffset_y\fP\fB, int \fIunit_type\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_packing (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_packswap (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_palette_to_rgb(png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIres_x\fP\fB, png_uint_32 \fP\fIres_y\fP\fB, int \fIunit_type\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_progressive_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIprogressive_ptr\fP\fB, png_progressive_info_ptr \fP\fIinfo_fn\fP\fB, png_progressive_row_ptr \fP\fIrow_fn\fP\fB, png_progressive_end_ptr \fIend_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fIread_data_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_read_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_read_status_ptr \fIread_row_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_read_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIread_user_transform_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_rgb_to_gray (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIerror_action\fP\fB, double \fP\fIred\fP\fB, double \fIgreen\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_rgb_to_gray_fixed (png_structp \fP\fIpng_ptr\fP\fB, int error_action png_fixed_point \fP\fIred\fP\fB, png_fixed_point \fIgreen\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytepp \fIrow_pointers\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fIsig_bit\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_sig_bytes (png_structp \fP\fIpng_ptr\fP\fB, int \fInum_bytes\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fP\fIsplt_ptr\fP\fB, int \fInum_spalettes\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIintent\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_sRGB_gAMA_and_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIintent\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_strip_16 (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_strip_alpha (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_swap (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_swap_alpha (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fItext_ptr\fP\fB, int \fInum_text\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fItrans\fP\fB, int \fP\fInum_trans\fP\fB, png_color_16p \fItrans_values\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_tRNS_to_alpha(png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBpng_uint_32 png_set_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkp \fP\fIunknowns\fP\fB, int \fP\fInum\fP\fB, int \fIlocation\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_unknown_chunk_location(png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIchunk\fP\fB, int \fIlocation\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_read_user_chunk_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_chunk_ptr\fP\fB, png_user_chunk_ptr \fIread_user_chunk_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_user_limits (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIuser_width_max\fP\fB, png_uint_32 \fIuser_height_max\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_user_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_transform_ptr\fP\fB, int \fP\fIuser_transform_depth\fP\fB, int \fIuser_transform_channels\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_write_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fP\fIwrite_data_fn\fP\fB, png_flush_ptr \fIoutput_flush_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_write_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_write_status_ptr \fIwrite_row_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_write_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIwrite_user_transform_fn\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_set_compression_buffer_size(png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
 
+\fI\fB
+
 \fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, png_size_t \fP\fIstart\fP\fB, png_size_t \fInum_to_check\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_start_read_image (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_chunk_end (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_chunk_start (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_destroy (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_flush (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP
 
+\fI\fB
+
 \fBDEPRECATED: void png_write_init (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBDEPRECATED: void png_write_init_2 (png_structpp \fP\fIptr_ptr\fP\fB, png_const_charp \fP\fIuser_png_ver\fP\fB, png_size_t \fP\fIpng_struct_size\fP\fB, png_size_t \fIpng_info_size\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_info_before_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_write_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP
 
+\fI\fB
+
 \fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP
 
+\fI\fB
+
 \fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP
 
+\fI\fB
+
 .SH DESCRIPTION
 The
 .I libpng
@@ -410,14 +821,18 @@ Following is a copy of the libpng.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.2.25 - February 18, 2008
+ libpng version 1.2.33 - October 31, 2008
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2008 Glenn Randers-Pehrson
  For conditions of distribution and use, see copyright
  notice in png.h.
 
- based on:
+ Based on:
+
+ libpng versions 0.97, January 1998, through 1.2.33 - October 31, 2008
+ Updated and distributed by Glenn Randers-Pehrson
+ Copyright (c) 1998-2008 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6  version 0.96 May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -457,12 +872,14 @@ a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
 The W3C and ISO documents have identical technical content.
 
 The PNG-1.2 specification is available at
-<http://www.libpng.org/pub/png/documents/>
+<http://www.libpng.org/pub/png/documents/>.  It is technically equivalent
+to the PNG specification (second edition) but has some additional material.
 
 The PNG-1.0 specification is available
 as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a
-W3C Recommendation <http://www.w3.org/TR/REC.png.html>. Some
-additional chunks are described in the special-purpose public chunks
+W3C Recommendation <http://www.w3.org/TR/REC.png.html>.
+
+Some additional chunks are described in the special-purpose public chunks
 documents at <http://www.libpng.org/pub/png/documents/>.
 
 Other information
@@ -670,15 +1087,19 @@ input stream. You must supply the function
          png_unknown_chunkp chunk);
     {
        /* The unknown chunk structure contains your
-          chunk data: */
+          chunk data, along with similar data for any other
+          unknown chunks: */
+
            png_byte name[5];
            png_byte *data;
            png_size_t size;
+
        /* Note that libpng has already taken care of
           the CRC handling */
 
-       /* put your code here.  Return one of the
-          following: */
+       /* put your code here.  Search for your chunk in the
+          unknown chunk structure, process it, and return one
+          of the following: */
 
        return (-n); /* chunk had an error */
        return (0); /* did not recognize */
@@ -698,6 +1119,11 @@ you can retrieve with
 
     png_get_user_chunk_ptr(png_ptr);
 
+If you call the png_set_read_user_chunk_fn() function, then all unknown
+chunks will be saved when read, in case your callback function will need
+one or more of them.  This behavior can be changed with the
+png_set_keep_unknown_chunks() function, described below.
+
 At this point, you can set up a callback function that will be
 called after each row has been read, which you can use to control
 a progress meter or the like.  It's demonstrated in pngtest.c.
@@ -742,13 +1168,14 @@ If you need to retrieve the limits that are being applied, use
 Now you get to set the way the library processes unknown chunks in the
 input PNG stream. Both known and unknown chunks will be read.  Normal
 behavior is that known chunks will be parsed into information in
-various info_ptr members; unknown chunks will be discarded. To change
-this, you can call:
+various info_ptr members while unknown chunks will be discarded. This
+behavior can be wasteful if your application will never use some known
+chunk types. To change this, you can call:
 
     png_set_keep_unknown_chunks(png_ptr, keep,
         chunk_list, num_chunks);
-    keep       - 0: do not handle as unknown
-                 1: do not keep
+    keep       - 0: default unknown chunk handling
+                 1: ignore; do not keep
                  2: keep only if safe-to-copy
                  3: keep even if unsafe-to-copy
                You can use these definitions:
@@ -771,6 +1198,37 @@ instances of png_set_keep_unknown_chunks(), the final instance will
 take precedence.  The IHDR and IEND chunks should not be named in
 chunk_list; if they are, libpng will process them normally anyway.
 
+Here is an example of the usage of png_set_keep_unknown_chunks(),
+where the private "vpAg" chunk will later be processed by a user chunk
+callback function:
+
+    png_byte vpAg[5]={118, 112,  65, 103, (png_byte) '\0'};
+
+    #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+      png_byte unused_chunks[]=
+      {
+        104,  73,  83,  84, (png_byte) '\0',   /* hIST */
+        105,  84,  88, 116, (png_byte) '\0',   /* iTXt */
+        112,  67,  65,  76, (png_byte) '\0',   /* pCAL */
+        115,  67,  65,  76, (png_byte) '\0',   /* sCAL */
+        115,  80,  76,  84, (png_byte) '\0',   /* sPLT */
+        116,  73,  77,  69, (png_byte) '\0',   /* tIME */
+      };
+    #endif
+
+    ...
+
+    #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+      /* ignore all unknown chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0);
+      /* except for vpAg: */
+      png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1);
+      /* also ignore unused known chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks,
+         (int)sizeof(unused_chunks)/5);
+    #endif
+
+
 .SS The high-level read interface
 
 At this point there are two ways to proceed; through the high-level
@@ -1214,6 +1672,7 @@ added.  It expands the sample depth without changing tRNS to alpha.
 At the same time, png_set_gray_1_2_4_to_8() was deprecated, and it
 will be removed from a future version.
 
+
 PNG can have files with 16 bits per channel.  If you only can handle
 8 bits per channel, this will strip the pixels down to 8 bit.
 
@@ -2153,6 +2612,11 @@ Some of the more important parts of the png_info are:
                      can also be
                      PNG_INTRAPIXEL_DIFFERENCING)
 
+If you call png_set_IHDR(), the call must appear before any of the
+other png_set_*() functions, which might require access to some of
+the IHDR settings.  The remaining png_set_*() functions can be called
+in any order.
+
     png_set_PLTE(png_ptr, info_ptr, palette,
        num_palette);
     palette        - the palette for the file
@@ -2801,6 +3265,9 @@ Your malloc_fn() must return NULL in case of failure.  The png_malloc()
 function will normally call png_error() if it receives a NULL from the
 system memory allocator or from your replacement malloc_fn().
 
+Your free_fn() will never be called with a NULL ptr, since libpng's
+png_free() checks for NULL before calling free_fn().
+
 Input/Output in libpng is done through png_read() and png_write(),
 which currently just call fread() and fwrite().  The FILE * is stored in
 png_struct and is initialized via png_init_io().  If you wish to change
@@ -3206,13 +3673,13 @@ application:
 
 .SH IX. Y2K Compliance in libpng
 
-February 18, 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 1.2.25 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 that
@@ -3428,6 +3895,42 @@ the first widely used release:
  1.2.24              13    10224  12.so.0.24[.0]
  1.2.25beta01-06     13    10225  12.so.0.25[.0]
  1.2.25rc01-02       13    10225  12.so.0.25[.0]
+ 1.0.31              10    10031  10.so.0.31[.0]
+ 1.2.25              13    10225  12.so.0.25[.0]
+ 1.2.26beta01-06     13    10226  12.so.0.26[.0]
+ 1.2.26rc01          13    10226  12.so.0.26[.0]
+ 1.2.26              13    10226  12.so.0.26[.0]
+ 1.0.32              10    10032  10.so.0.32[.0]
+ 1.2.27beta01-06     13    10227  12.so.0.27[.0]
+ 1.2.27rc01          13    10227  12.so.0.27[.0]
+ 1.0.33              10    10033  10.so.0.33[.0]
+ 1.2.27              13    10227  12.so.0.27[.0]
+ 1.0.34              10    10034  10.so.0.34[.0]
+ 1.2.28              13    10228  12.so.0.28[.0]
+ 1.2.29beta01-03     13    10229  12.so.0.29[.0]
+ 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 minor
 and patch numbers; the shared-library major version number will be
@@ -3463,7 +3966,7 @@ ftp://ftp.info-zip.org/pub/infozip/zlib
 .I libpng
 or at
 .br
-ftp://ds.internic.net/rfc/rfc2083.txt
+ftp://ftp.rfc-editor.org:/in-notes/rfc2083.txt
 .br
 or (as a W3C Recommendation) at
 .br
@@ -3483,7 +3986,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.2.25 - February 18, 2008:
+Libpng version 1.2.33 - October 31, 2008:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -3504,7 +4007,7 @@ included in the libpng distribution, the latter shall prevail.)
 If you modify libpng you may insert additional notices immediately following
 this sentence.
 
-libpng versions 1.2.6, August 15, 2004, through 1.2.25, February 18, 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
@@ -3603,7 +4106,7 @@ certification mark of the Open Source Initiative.
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-February 18, 2008
+October 31, 2008
 
 .\" end of man page
 
diff --git a/png/libpng.txt b/png/libpng.txt
index 5b8dc53b9..ef51fc88d 100644
--- a/png/libpng.txt
+++ b/png/libpng.txt
@@ -1,13 +1,17 @@
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.2.24 - December 14, 2007
+ libpng version 1.2.33 - October 31, 2008
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2007 Glenn Randers-Pehrson
+ Copyright (c) 1998-2008 Glenn Randers-Pehrson
  For conditions of distribution and use, see copyright
  notice in png.h.
 
- based on:
+ Based on:
+
+ libpng versions 0.97, January 1998, through 1.2.33 - October 31, 2008
+ Updated and distributed by Glenn Randers-Pehrson
+ Copyright (c) 1998-2008 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6  version 0.96 May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -47,12 +51,14 @@ a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
 The W3C and ISO documents have identical technical content.
 
 The PNG-1.2 specification is available at
-<http://www.libpng.org/pub/png/documents/>
+<http://www.libpng.org/pub/png/documents/>.  It is technically equivalent
+to the PNG specification (second edition) but has some additional material.
 
 The PNG-1.0 specification is available
 as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a
-W3C Recommendation <http://www.w3.org/TR/REC.png.html>. Some
-additional chunks are described in the special-purpose public chunks
+W3C Recommendation <http://www.w3.org/TR/REC.png.html>.
+
+Some additional chunks are described in the special-purpose public chunks
 documents at <http://www.libpng.org/pub/png/documents/>.
 
 Other information
@@ -260,15 +266,19 @@ input stream. You must supply the function
          png_unknown_chunkp chunk);
     {
        /* The unknown chunk structure contains your
-          chunk data: */
+          chunk data, along with similar data for any other
+          unknown chunks: */
+
            png_byte name[5];
            png_byte *data;
            png_size_t size;
+
        /* Note that libpng has already taken care of
           the CRC handling */
 
-       /* put your code here.  Return one of the
-          following: */
+       /* put your code here.  Search for your chunk in the
+          unknown chunk structure, process it, and return one
+          of the following: */
 
        return (-n); /* chunk had an error */
        return (0); /* did not recognize */
@@ -288,6 +298,11 @@ you can retrieve with
 
     png_get_user_chunk_ptr(png_ptr);
 
+If you call the png_set_read_user_chunk_fn() function, then all unknown
+chunks will be saved when read, in case your callback function will need
+one or more of them.  This behavior can be changed with the
+png_set_keep_unknown_chunks() function, described below.
+
 At this point, you can set up a callback function that will be
 called after each row has been read, which you can use to control
 a progress meter or the like.  It's demonstrated in pngtest.c.
@@ -332,13 +347,14 @@ Unknown-chunk handling
 Now you get to set the way the library processes unknown chunks in the
 input PNG stream. Both known and unknown chunks will be read.  Normal
 behavior is that known chunks will be parsed into information in
-various info_ptr members; unknown chunks will be discarded. To change
-this, you can call:
+various info_ptr members while unknown chunks will be discarded. This
+behavior can be wasteful if your application will never use some known
+chunk types. To change this, you can call:
 
     png_set_keep_unknown_chunks(png_ptr, keep,
         chunk_list, num_chunks);
-    keep       - 0: do not handle as unknown
-                 1: do not keep
+    keep       - 0: default unknown chunk handling
+                 1: ignore; do not keep
                  2: keep only if safe-to-copy
                  3: keep even if unsafe-to-copy
                You can use these definitions:
@@ -361,6 +377,37 @@ instances of png_set_keep_unknown_chunks(), the final instance will
 take precedence.  The IHDR and IEND chunks should not be named in
 chunk_list; if they are, libpng will process them normally anyway.
 
+Here is an example of the usage of png_set_keep_unknown_chunks(),
+where the private "vpAg" chunk will later be processed by a user chunk
+callback function:
+
+    png_byte vpAg[5]={118, 112,  65, 103, (png_byte) '\0'};
+
+    #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+      png_byte unused_chunks[]=
+      {
+        104,  73,  83,  84, (png_byte) '\0',   /* hIST */
+        105,  84,  88, 116, (png_byte) '\0',   /* iTXt */
+        112,  67,  65,  76, (png_byte) '\0',   /* pCAL */
+        115,  67,  65,  76, (png_byte) '\0',   /* sCAL */
+        115,  80,  76,  84, (png_byte) '\0',   /* sPLT */
+        116,  73,  77,  69, (png_byte) '\0',   /* tIME */
+      };
+    #endif
+
+    ...
+
+    #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+      /* ignore all unknown chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0);
+      /* except for vpAg: */
+      png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1);
+      /* also ignore unused known chunks: */
+      png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks,
+         (int)sizeof(unused_chunks)/5);
+    #endif
+
+
 The high-level read interface
 
 At this point there are two ways to proceed; through the high-level
@@ -804,6 +851,7 @@ added.  It expands the sample depth without changing tRNS to alpha.
 At the same time, png_set_gray_1_2_4_to_8() was deprecated, and it
 will be removed from a future version.
 
+
 PNG can have files with 16 bits per channel.  If you only can handle
 8 bits per channel, this will strip the pixels down to 8 bit.
 
@@ -1743,6 +1791,11 @@ Some of the more important parts of the png_info are:
                      can also be
                      PNG_INTRAPIXEL_DIFFERENCING)
 
+If you call png_set_IHDR(), the call must appear before any of the
+other png_set_*() functions, which might require access to some of
+the IHDR settings.  The remaining png_set_*() functions can be called
+in any order.
+
     png_set_PLTE(png_ptr, info_ptr, palette,
        num_palette);
     palette        - the palette for the file
@@ -2391,6 +2444,9 @@ Your malloc_fn() must return NULL in case of failure.  The png_malloc()
 function will normally call png_error() if it receives a NULL from the
 system memory allocator or from your replacement malloc_fn().
 
+Your free_fn() will never be called with a NULL ptr, since libpng's
+png_free() checks for NULL before calling free_fn().
+
 Input/Output in libpng is done through png_read() and png_write(),
 which currently just call fread() and fwrite().  The FILE * is stored in
 png_struct and is initialized via png_init_io().  If you wish to change
@@ -2796,13 +2852,13 @@ application:
 
 IX. Y2K Compliance in libpng
 
-December 14, 2007
+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 1.2.24 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 that
diff --git a/png/libpngpf.3 b/png/libpngpf.3
index a5b09b6e4..51eabca74 100644
--- a/png/libpngpf.3
+++ b/png/libpngpf.3
@@ -1,266 +1,782 @@
-.TH LIBPNGPF 3 "February 18, 2008"
+.TH LIBPNGPF 3 "October 31, 2008"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.2.25
+libpng \- Portable Network Graphics (PNG) Reference Library 1.2.33
 (private functions)
 .SH SYNOPSIS
 \fB#include <png.h>\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_build_gamma_table (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_build_grayscale_palette (int \fP\fIbit_depth\fP\fB, png_colorp \fIpalette\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_calculate_crc (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIptr\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_check_chunk_name (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBpng_size_t png_check_keyword (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charpp \fInew_key\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fImask\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_correct_palette (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBint png_crc_error (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBint png_crc_finish (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIskip\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_crc_read (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuf\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBpng_voidp png_create_struct (int \fItype\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBpng_voidp png_create_struct_2 (int \fP\fItype\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_voidp \fImem_ptr\fP\fB);\fP
 
-\fBpng_charp png_decompress_chunk (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcomp_type\fP\fB, png_charp \fP\fIchunkdata\fP\fB, png_size_t \fP\fIchunklength\fP\fB, png_size_t \fP\fIprefix_length\fP\fB, png_size_t \fI*data_length\fP\fB);\fP
+\fI\fB
+
+\fI\fB
+
+\fBvoid png_decompress_chunk (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcomp_type\fP\fB, png_charp \fP\fIchunkdata\fP\fB, png_size_t \fP\fIchunklength\fP\fB, png_size_t \fP\fIprefix_length\fP\fB, png_size_t \fI*data_length\fP\fB);\fP
+
+\fI\fB
+
+\fI\fB
 
 \fBvoid png_destroy_struct (png_voidp \fIstruct_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_destroy_struct_2 (png_voidp \fP\fIstruct_ptr\fP\fB, png_free_ptr \fP\fIfree_fn\fP\fB, png_voidp \fImem_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_background (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_16p \fP\fItrans_values\fP\fB, png_color_16p \fP\fIbackground\fP\fB, png_color_16p \fP\fIbackground_1\fP\fB, png_bytep \fP\fIgamma_table\fP\fB, png_bytep \fP\fIgamma_from_1\fP\fB, png_bytep \fP\fIgamma_to_1\fP\fB, png_uint_16pp \fP\fIgamma_16\fP\fB, png_uint_16pp \fP\fIgamma_16_from_1\fP\fB, png_uint_16pp \fP\fIgamma_16_to_1\fP\fB, int \fIgamma_shift\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_bgr (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_chop (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_dither (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIpalette_lookup\fP\fB, png_bytep \fIdither_lookup\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_expand (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_16p \fItrans_value\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_expand_palette (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_colorp \fP\fIpalette\fP\fB, png_bytep \fP\fItrans\fP\fB, int \fInum_trans\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_gamma (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIgamma_table\fP\fB, png_uint_16pp \fP\fIgamma_16_table\fP\fB, int \fIgamma_shift\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_gray_to_rgb (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_invert (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_pack (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fIbit_depth\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_packswap (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_read_filler (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, png_uint_32 \fIflags\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_read_interlace (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fP\fIpass\fP\fB, png_uint_32 \fItransformations\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_read_invert_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_read_swap_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_read_transformations (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBint png_do_rgb_to_gray (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_shift (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_8p \fIbit_depth\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_strip_filler (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fIflags\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_swap (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_unpack (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_unshift (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_8p \fIsig_bits\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_write_interlace (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fIpass\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_write_invert_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_write_swap_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_do_write_transformations (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid *png_far_to_near (png_structp png_ptr,png_voidp \fP\fIptr\fP\fB, int \fIcheck\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_flush (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_IEND (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_iTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_handle_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_info_destroy (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_init_mmx_flags (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_init_read_transformations (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_process_IDAT_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_length\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_process_some_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_check_crc (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_crc_finish (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_crc_skip (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_fill_buffer (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_handle_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_handle_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_handle_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_have_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_have_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_have_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_process_row (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_read_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_read_IDAT (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_read_sig (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_read_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_read_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_restore_buffer (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_length\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_push_save_buffer (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
+\fBpng_uint_32 png_read_chunk_header (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_read_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_read_filter_row (png_structp \fP\fIpng_ptr\fP\fB, png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIprev_row\fP\fB, int \fIfilter\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_read_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_read_push_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_read_start_row (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_read_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_reset_crc (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBint png_set_text_2 (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fItext_ptr\fP\fB, int \fInum_text\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_cHRM (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \fIblue_y\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_filtered_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIfiltered_row\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_find_filter (png_structp \fP\fIpng_ptr\fP\fB, png_row_infop \fIrow_info\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_gAMA (png_structp \fP\fIpng_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIint_file_gamma\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_uint_16p \fP\fIhist\fP\fB, int \fInum_hist\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_charp \fP\fIprofile\fP\fB, int \fIproflen\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_IDAT (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_IEND (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fP\fIfilter_type\fP\fB, int \fIinterlace_type\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_iTXt (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcompression\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fIlang\fP\fB, png_charp \fP\fItranslated_key\fP\fB, png_charp \fItext\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIx_offset\fP\fB, png_uint_32 \fP\fIy_offset\fP\fB, int \fIunit_type\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIx_pixels_per_unit\fP\fB, png_uint_32 \fP\fIy_pixels_per_unit\fP\fB, int \fIunit_type\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, png_uint_32 \fInum_pal\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fP\fIsbit\fP\fB, int \fIcolor_type\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_sCAL_s (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, png_charp \fP\fIwidth\fP\fB, png_charp \fIheight\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_sig (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_sRGB (png_structp \fP\fIpng_ptr\fP\fB, int \fIintent\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_spalette_p \fIpalette\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_start_row (png_structp \fIpng_ptr\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fItext\fP\fB, png_size_t \fItext_len\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fItrans\fP\fB, png_color_16p \fP\fIvalues\fP\fB, int \fP\fInumber\fP\fB, int \fIcolor_type\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_write_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fItext\fP\fB, png_size_t \fP\fItext_len\fP\fB, int \fIcompression\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP
 
+\fI\fB
+
+\fI\fB
+
 \fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP
 
 \fI\fB
 
+\fI\fB
+
 .SH DESCRIPTION
 The functions listed above are used privately by libpng
 and are not recommended for use by applications.  They are
diff --git a/png/png.5 b/png/png.5
index 6b5aa3a03..e5a903683 100644
--- a/png/png.5
+++ b/png/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "February 18, 2008"
+.TH PNG 5 "October 31, 2008"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
@@ -35,7 +35,7 @@ PNG 1.0 specification, October 1996:
 RFC 2083
 .IP
 .br
-ftp://ds.internic.net/rfc/rfc2083.txt
+ftp://ftp.rfc-editor.org:/in-notes/rfc2083.txt
 .br
 or (as a W3C Recommendation) at
 .br
diff --git a/png/png.c b/png/png.c
index e07acff8a..2e9adf909 100644
--- a/png/png.c
+++ b/png/png.c
@@ -1,7 +1,7 @@
 
 /* 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) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -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_25 Your_png_h_is_not_version_1_2_25;
+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.  */
@@ -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
 
@@ -490,6 +490,7 @@ if (mask & PNG_FREE_SPLT)
     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
@@ -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 1.2.25 - February 18, 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");
diff --git a/png/png.h b/png/png.h
index 6e538552c..7faa0213f 100644
--- a/png/png.h
+++ b/png/png.h
@@ -1,7 +1,6 @@
-
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.2.25 - February 18, 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.)
@@ -9,7 +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 1.2.25 - February 18, 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:
@@ -177,6 +176,42 @@
  *    1.2.24                  13    10224  12.so.0.24[.0]
  *    1.2.25beta01-06         13    10225  12.so.0.25[.0]
  *    1.2.25rc01-02           13    10225  12.so.0.25[.0]
+ *    1.0.31                  10    10031  10.so.0.31[.0]
+ *    1.2.25                  13    10225  12.so.0.25[.0]
+ *    1.2.26beta01-06         13    10226  12.so.0.26[.0]
+ *    1.2.26rc01              13    10226  12.so.0.26[.0]
+ *    1.2.26                  13    10226  12.so.0.26[.0]
+ *    1.0.32                  10    10032  10.so.0.32[.0]
+ *    1.2.27beta01-06         13    10227  12.so.0.27[.0]
+ *    1.2.27rc01              13    10227  12.so.0.27[.0]
+ *    1.0.33                  10    10033  10.so.0.33[.0]
+ *    1.2.27                  13    10227  12.so.0.27[.0]
+ *    1.0.34                  10    10034  10.so.0.34[.0]
+ *    1.2.28                  13    10228  12.so.0.28[.0]
+ *    1.2.29beta01-03         13    10229  12.so.0.29[.0]
+ *    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
@@ -186,7 +221,7 @@
  *    to the source version x.y.z (leading zeros in y and z).  Beta versions
  *    were given the previous public release number plus a letter, until
  *    version 1.0.6j; from then on they were given the upcoming public
- *    release number plus "betaNN" or "rcN".
+ *    release number plus "betaNN" or "rcNN".
  *
  *    Binary incompatibility exists only when applications make direct access
  *    to the info_ptr or png_ptr members through png.h, and the compiled
@@ -206,7 +241,7 @@
  * If you modify libpng you may insert additional notices immediately following
  * this sentence.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.2.25, February 18, 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:
@@ -318,13 +353,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    February 18, 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 1.2.25 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
@@ -380,9 +415,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.2.25"
+#define PNG_LIBPNG_VER_STRING "1.2.33"
 #define PNG_HEADER_VERSION_STRING \
-   " libpng version 1.2.25 - February 18, 2008\n"
+   " libpng version 1.2.33 - October 31, 2008\n"
 
 #define PNG_LIBPNG_VER_SONUM   0
 #define PNG_LIBPNG_VER_DLLNUM  13
@@ -390,7 +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 25
+#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: */
 
@@ -418,7 +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 10225 /* 1.2.25 */
+#define PNG_LIBPNG_VER 10233 /* 1.2.33 */
 
 #ifndef PNG_VERSION_INFO_ONLY
 /* include the compression library's header */
@@ -1189,7 +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 */
@@ -1426,13 +1461,20 @@ struct png_struct_def
    /* storage for unknown chunk that the library doesn't recognize. */
    png_unknown_chunk unknown_chunk;
 #endif
+
+/* 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_25;
+typedef png_structp version_1_2_33;
 
 typedef png_struct FAR * FAR * png_structpp;
 
@@ -2627,6 +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
@@ -3008,8 +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
 
@@ -3538,6 +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/png/pngconf.h b/png/pngconf.h
index b8e6844c1..05995f308 100644
--- a/png/pngconf.h
+++ b/png/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.2.25 - February 18, 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)
diff --git a/png/pngerror.c b/png/pngerror.c
index f2ee80087..f4223b3c4 100644
--- a/png/pngerror.c
+++ b/png/pngerror.c
@@ -1,7 +1,7 @@
 
 /* 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) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -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));
@@ -44,16 +44,17 @@ 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) == ' ')
+              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';
+              msg[i - 1] = '\0';
               error_message=msg;
            }
            else
@@ -111,7 +112,7 @@ png_warning(png_structp png_ptr, png_const_charp warning_message)
        if (*warning_message == '#')
        {
            for (offset=1; offset<15; offset++)
-              if (*(warning_message+offset) == ' ')
+              if (warning_message[offset] == ' ')
                   break;
        }
      }
@@ -216,19 +217,20 @@ 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++)
      {
-         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))
      {
        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);
@@ -276,13 +278,13 @@ png_default_warning(png_structp png_ptr, png_const_charp warning_message)
      char warning_number[16];
      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))
      {
-       warning_number[offset-1]='\0';
+       warning_number[offset + 1] = '\0';
        fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
           warning_message+offset);
      }
diff --git a/png/pngget.c b/png/pngget.c
index 0dd8f2588..ca7f92e9c 100644
--- a/png/pngget.c
+++ b/png/pngget.c
@@ -1,7 +1,7 @@
 
 /* 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) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -10,7 +10,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
 png_uint_32 PNGAPI
diff --git a/png/pngmem.c b/png/pngmem.c
index 58241c628..aeed12f76 100644
--- a/png/pngmem.c
+++ b/png/pngmem.c
@@ -1,7 +1,7 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * 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) 1998-2008 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 */
@@ -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) return;
+   if (png_ptr == NULL || ptr == NULL) return;
 
    if (png_ptr->offset_table != NULL)
    {
@@ -456,7 +456,7 @@ png_malloc_default(png_structp png_ptr, png_uint_32 size)
    if (size > (png_uint_32)65536L)
    {
 #ifndef PNG_USER_MEM_SUPPORTED
-      if(png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
          png_error(png_ptr, "Cannot Allocate > 64K");
       else
 #endif
@@ -587,7 +587,8 @@ 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) {
+   if (png_ptr != NULL)
+   {
    png_ptr->mem_ptr = mem_ptr;
    png_ptr->malloc_fn = malloc_fn;
    png_ptr->free_fn = free_fn;
diff --git a/png/pngpread.c b/png/pngpread.c
index a02cdfcb2..b143673fc 100644
--- a/png/pngpread.c
+++ b/png/pngpread.c
@@ -1,7 +1,7 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.2.25 [February 18, 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 */
@@ -213,6 +212,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
       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;
    }
 
@@ -222,6 +222,8 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
    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)
       {
          png_push_save_buffer(png_ptr);
@@ -1018,23 +1020,21 @@ 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->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[pass] - 1 -
-                png_pass_start[pass]) /
-                png_pass_inc[pass];
+            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;
@@ -1043,12 +1043,9 @@ png_read_push_finish_row(png_structp png_ptr)
                 break;
 
              png_ptr->num_rows = (png_ptr->height +
-                png_pass_yinc[pass] - 1 -
-                png_pass_ystart[pass]) /
-                png_pass_yinc[pass];
-           }
-         else
-           break;
+            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);
    }
@@ -1266,8 +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);
@@ -1281,8 +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,
@@ -1467,7 +1464,6 @@ 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);
 
    if (!(png_ptr->chunk_name[0] & 0x20))
    {
@@ -1498,11 +1494,18 @@ 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.data = (png_bytep)png_malloc(png_ptr, length);
       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,
+       (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)
       {
diff --git a/png/pngread.c b/png/pngread.c
index bd8bcd98a..0f3017981 100644
--- a/png/pngread.c
+++ b/png/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
@@ -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_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
@@ -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");
          }
@@ -920,9 +907,6 @@ 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;
    png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
@@ -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;
 
@@ -1159,6 +1135,8 @@ 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);
@@ -1167,6 +1145,7 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
 #endif
    *png_ptr_ptr = NULL;
 }
+}
 
 /* free all memory used by the read (old method) */
 void /* PRIVATE */
@@ -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);
diff --git a/png/pngrio.c b/png/pngrio.c
index bbbb4352c..cd1f7bfb9 100644
--- a/png/pngrio.c
+++ b/png/pngrio.c
@@ -1,7 +1,7 @@
 
 /* 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) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -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
diff --git a/png/pngrtran.c b/png/pngrtran.c
index c020b51b3..bf69ff971 100644
--- a/png/pngrtran.c
+++ b/png/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * 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)
@@ -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. */
@@ -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:
@@ -548,9 +548,7 @@ png_set_expand(png_structp png_ptr)
    png_debug(1, "in png_set_expand\n");
    if(png_ptr == NULL) return;
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-#ifdef PNG_WARN_UNINITIALIZED_ROW
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-#endif
 }
 
 /* GRR 19990627:  the following three functions currently are identical
@@ -577,9 +575,7 @@ png_set_palette_to_rgb(png_structp png_ptr)
    png_debug(1, "in png_set_palette_to_rgb\n");
    if(png_ptr == NULL) return;
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-#ifdef PNG_WARN_UNINITIALIZED_ROW
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-#endif
 }
 
 #if !defined(PNG_1_0_X)
@@ -590,9 +586,7 @@ 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;
    png_ptr->transformations |= PNG_EXPAND;
-#ifdef PNG_WARN_UNINITIALIZED_ROW
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-#endif
 }
 #endif
 
@@ -615,9 +609,7 @@ png_set_tRNS_to_alpha(png_structp png_ptr)
 {
    png_debug(1, "in png_set_tRNS_to_alpha\n");
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-#ifdef PNG_WARN_UNINITIALIZED_ROW
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-#endif
 }
 #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
 
@@ -627,9 +619,7 @@ png_set_gray_to_rgb(png_structp png_ptr)
 {
    png_debug(1, "in png_set_gray_to_rgb\n");
    png_ptr->transformations |= PNG_GRAY_TO_RGB;
-#ifdef PNG_WARN_UNINITIALIZED_ROW
    png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
-#endif
 }
 #endif
 
@@ -669,7 +659,8 @@ 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
@@ -693,7 +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
@@ -967,7 +959,7 @@ png_init_read_transformations(png_structp png_ptr)
 	    /* Prevent the transformations being done again, and make sure
 	     * that the now spurious alpha channel is stripped - the code
 	     * has just reduced background composition and gamma correction
-	     * to a simply alpha channel strip.
+	     * to a simple alpha channel strip.
 	     */
 	    png_ptr->transformations &= ~PNG_BACKGROUND;
 	    png_ptr->transformations &= ~PNG_GAMMA;
@@ -1138,7 +1130,8 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
    {
       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       {
-         if (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND_tRNS))
+         if (png_ptr->num_trans &&
+              (png_ptr->transformations & PNG_EXPAND_tRNS))
             info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
          else
             info_ptr->color_type = PNG_COLOR_TYPE_RGB;
@@ -1151,8 +1144,10 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
          {
             if (png_ptr->transformations & PNG_EXPAND_tRNS)
               info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+#if 0 /* Removed from libpng-1.2.27 */
             else
               info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
+#endif
          }
          if (info_ptr->bit_depth < 8)
             info_ptr->bit_depth = 8;
@@ -1280,7 +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
@@ -2217,8 +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
  *
diff --git a/png/pngrutil.c b/png/pngrutil.c
index 990e69802..233a64804 100644
--- a/png/pngrutil.c
+++ b/png/pngrutil.c
@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.2.25 [February 18, 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);
@@ -92,6 +99,35 @@ 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)
@@ -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_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;
          }
@@ -242,12 +280,14 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
                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);
@@ -308,10 +350,11 @@ png_decompress_chunk(png_structp png_ptr, int comp_type,
             text = (png_charp)png_malloc_warn(png_ptr, text_size+1);
             if (text == NULL)
               {
-                png_free(png_ptr, chunkdata);
+                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;
+      *(png_ptr->chunkdata + prefix_size) = 0x00;
       *newlength=prefix_size;
    }
-
-   return chunkdata;
 }
 #endif
 
@@ -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;
@@ -866,7 +890,6 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #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
 
@@ -949,7 +970,8 @@ 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);
@@ -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;
    }
@@ -1060,21 +1084,22 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
                                  wrote nonzero) */
    }
 
-   prefix_length = profile - chunkdata;
-   chunkdata = png_decompress_chunk(png_ptr, compression_type, chunkdata,
+   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);
+   pC = (png_bytep)(png_ptr->chunkdata + prefix_length);
    profile_size = ((*(pC  ))<<24) |
                   ((*(pC+1))<<16) |
                   ((*(pC+2))<< 8) |
@@ -1085,14 +1110,16 @@ png_handle_iCCP(png_structp png_ptr, png_infop info_ptr, png_uint_32 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 */
@@ -1241,15 +1272,9 @@ void /* PRIVATE */
 png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
    png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
-   int bit_mask;
 
    png_debug(1, "in png_handle_tRNS\n");
 
-   /* For non-indexed color, mask off any bits in the tRNS value that
-    * exceed the bit depth.  Some creators were writing extra bits there.
-    * This is not needed for indexed color. */
-   bit_mask = (1 << png_ptr->bit_depth) - 1;
-
    if (!(png_ptr->mode & PNG_HAVE_IHDR))
       png_error(png_ptr, "Missing IHDR before tRNS");
    else if (png_ptr->mode & PNG_HAVE_IDAT)
@@ -1278,7 +1303,7 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
       png_crc_read(png_ptr, buf, 2);
       png_ptr->num_trans = 1;
-      png_ptr->trans_values.gray = png_get_uint_16(buf) & bit_mask;
+      png_ptr->trans_values.gray = png_get_uint_16(buf);
    }
    else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
    {
@@ -1292,9 +1317,9 @@ png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       }
       png_crc_read(png_ptr, buf, (png_size_t)length);
       png_ptr->num_trans = 1;
-      png_ptr->trans_values.red = png_get_uint_16(buf) & bit_mask;
-      png_ptr->trans_values.green = png_get_uint_16(buf + 2) & bit_mask;
-      png_ptr->trans_values.blue = png_get_uint_16(buf + 4) & bit_mask;
+      png_ptr->trans_values.red = png_get_uint_16(buf);
+      png_ptr->trans_values.green = png_get_uint_16(buf + 2);
+      png_ptr->trans_values.blue = png_get_uint_16(buf + 4);
    }
    else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
    {
@@ -1571,7 +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;
@@ -1598,35 +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;
    }
 
@@ -1646,7 +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)
@@ -1658,11 +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;
      }
@@ -1680,16 +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
@@ -1699,7 +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;
@@ -1729,24 +1760,25 @@ 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_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);
@@ -1767,18 +1799,19 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #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");
 #if defined(PNG_FIXED_POINT_SUPPORTED) && \
     !defined(PNG_FLOATING_POINT_SUPPORTED)
        png_free(png_ptr, swidth);
 #endif
-      png_free(png_ptr, buffer);
+      png_free(png_ptr, png_ptr->chunkdata);
+      png_ptr->chunkdata = NULL;
        return;
    }
 
@@ -1801,14 +1834,15 @@ png_handle_sCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 #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);
@@ -1818,14 +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);
@@ -1905,21 +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++)
@@ -1933,7 +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;
@@ -1948,7 +1987,8 @@ png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
    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.");
@@ -1961,7 +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;
@@ -1985,30 +2024,33 @@ png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 #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.");
      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
@@ -2021,9 +2063,9 @@ 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_decompress_chunk(png_ptr, comp_type,
                                     (png_size_t)length, prefix_len, &data_len);
 
    text_ptr = (png_textp)png_malloc_warn(png_ptr,
@@ -2031,23 +2073,25 @@ png_handle_zTXt(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 zTXt chunk.");
-     png_free(png_ptr, chunkdata);
+     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);
 
    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.");
 }
@@ -2059,7 +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;
@@ -2085,23 +2128,25 @@ png_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    }
 #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 */
 
@@ -2109,10 +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
@@ -2125,51 +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,
+       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_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);
 
    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.");
 }
@@ -2196,8 +2246,6 @@ 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)
@@ -2227,9 +2275,14 @@ png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
                   (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.data = (png_bytep)png_malloc(png_ptr, length);
        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_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)
        {
@@ -2851,6 +2904,7 @@ void /* PRIVATE */
 png_read_finish_row(png_structp png_ptr)
 {
 #ifdef PNG_USE_LOCAL_ARRAYS
+#ifdef PNG_READ_INTERLACING_SUPPORTED
    /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* start of interlace block */
@@ -2864,6 +2918,7 @@ png_read_finish_row(png_structp png_ptr)
 
    /* offset to next interlace block in the y direction */
    PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
 #endif
 
    png_debug(1, "in png_read_finish_row\n");
@@ -2871,6 +2926,7 @@ png_read_finish_row(png_structp png_ptr)
    if (png_ptr->row_number < png_ptr->num_rows)
       return;
 
+#ifdef PNG_READ_INTERLACING_SUPPORTED
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
@@ -2905,6 +2961,7 @@ png_read_finish_row(png_structp png_ptr)
       if (png_ptr->pass < 7)
          return;
    }
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
 
    if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
    {
@@ -2979,6 +3036,7 @@ void /* PRIVATE */
 png_read_start_row(png_structp png_ptr)
 {
 #ifdef PNG_USE_LOCAL_ARRAYS
+#ifdef PNG_READ_INTERLACING_SUPPORTED
    /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* start of interlace block */
@@ -2993,13 +3051,15 @@ png_read_start_row(png_structp png_ptr)
    /* offset to next interlace block in the y direction */
    PNG_CONST int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
 #endif
+#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;
    png_init_read_transformations(png_ptr);
+#ifdef PNG_READ_INTERLACING_SUPPORTED
    if (png_ptr->interlaced)
    {
       if (!(png_ptr->transformations & PNG_INTERLACE))
@@ -3013,13 +3073,11 @@ 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 */
    {
       png_ptr->num_rows = png_ptr->height;
       png_ptr->iwidth = png_ptr->width;
@@ -3138,8 +3196,14 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
    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)
+   {
+     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;
+   }
 
 #ifdef PNG_MAX_MALLOC_64K
    if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L)
@@ -3147,8 +3211,14 @@ defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
 #endif
    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)
+   {
+     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;
+   }
 
    png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
 
diff --git a/png/pngset.c b/png/pngset.c
index 9301dd327..da87a0f91 100644
--- a/png/pngset.c
+++ b/png/pngset.c
@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * 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)
@@ -15,7 +15,6 @@
 
 #define PNG_INTERNAL
 #include "png.h"
-
 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
 #if defined(PNG_bKGD_SUPPORTED)
@@ -396,7 +395,8 @@ 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)
      {
@@ -412,7 +412,8 @@ 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)
      {
@@ -434,7 +435,8 @@ png_set_pCAL(png_structp png_ptr, png_infop info_ptr,
    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)
         {
@@ -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;
@@ -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);
@@ -835,11 +841,13 @@ 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,
@@ -921,30 +929,45 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
         * we do it for backward compatibility with the way the png_handle_tRNS
         * 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);
-       if (num_trans <= PNG_MAX_PALETTE_LENGTH)
+       if (num_trans > 0 && num_trans <= PNG_MAX_PALETTE_LENGTH)
          png_memcpy(info_ptr->trans, trans, (png_size_t)num_trans);
-#ifdef PNG_FREE_ME_SUPPORTED
-       info_ptr->free_me |= PNG_FREE_TRNS;
-#else
-       png_ptr->flags |= PNG_FLAG_FREE_TRNS;
-#endif
    }
 
    if (trans_values != NULL)
    {
+      int sample_max = (1 << info_ptr->bit_depth);
+      if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY &&
+          (int)trans_values->gray > sample_max) ||
+          (info_ptr->color_type == PNG_COLOR_TYPE_RGB &&
+          ((int)trans_values->red > sample_max ||
+          (int)trans_values->green > sample_max ||
+          (int)trans_values->blue > sample_max)))
+        png_warning(png_ptr,
+           "tRNS chunk has out-of-range samples for bit_depth");
       png_memcpy(&(info_ptr->trans_values), trans_values,
          png_sizeof(png_color_16));
       if (num_trans == 0)
         num_trans = 1;
    }
+
    info_ptr->num_trans = (png_uint_16)num_trans;
+   if (num_trans != 0)
+   {
    info_ptr->valid |= PNG_INFO_tRNS;
+#ifdef PNG_FREE_ME_SUPPORTED
+      info_ptr->free_me |= PNG_FREE_TRNS;
+#else
+      png_ptr->flags |= PNG_FLAG_FREE_TRNS;
+#endif
+   }
 }
 #endif
 
@@ -952,6 +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;
@@ -960,7 +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.");
@@ -988,7 +1019,7 @@ 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,
@@ -1024,8 +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,
@@ -1047,20 +1078,24 @@ png_set_unknown_chunks(png_structp png_ptr,
                    (png_charp)from->name, 
                    png_sizeof(from->name));
         to->name[png_sizeof(to->name)-1] = '\0';
+       to->size = from->size;
+       /* note our location in the read or write sequence */
+       to->location = (png_byte)(png_ptr->mode & 0xff);
 
-        to->data = (png_bytep)png_malloc_warn(png_ptr, from->size);
+       if (from->size == 0)
+          to->data=NULL;
+       else
+       {
+          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;
         }
         else
-        {
            png_memcpy(to->data, from->data, from->size);
-           to->size = from->size;
-
-           /* note our location in the read or write sequence */
-           to->location = (png_byte)(png_ptr->mode & 0xff);
         }
     }
 
@@ -1137,7 +1172,8 @@ png_set_keep_unknown_chunks(png_structp png_ptr, int keep, png_bytep
       return;
     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)));
+       (png_uint_32)
+       (5*(num_chunks + old_num_chunks)));
     if(png_ptr->chunk_list != NULL)
     {
        png_memcpy(new_list, png_ptr->chunk_list,
@@ -1189,11 +1225,11 @@ png_set_rows(png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers)
 
 #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;
-    if(png_ptr->zbuf)
        png_free(png_ptr, png_ptr->zbuf);
     png_ptr->zbuf_size = (png_size_t)size;
     png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, size);
@@ -1219,6 +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 */
@@ -1230,6 +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 */
 
diff --git a/png/pngtrans.c b/png/pngtrans.c
index 4527b24d4..85f6a71f3 100644
--- a/png/pngtrans.c
+++ b/png/pngtrans.c
@@ -1,7 +1,7 @@
 
 /* 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) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -10,8 +10,8 @@
 
 #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
@@ -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/png/pngwio.c b/png/pngwio.c
index ad1f61ae8..d4386a7f8 100644
--- a/png/pngwio.c
+++ b/png/pngwio.c
@@ -1,7 +1,7 @@
 
 /* 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) 1998-2008 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
diff --git a/png/pngwrite.c b/png/pngwrite.c
index 8b01025f5..3a5d6bde3 100644
--- a/png/pngwrite.c
+++ b/png/pngwrite.c
@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.2.25 [February 18, 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)
@@ -112,6 +112,8 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
          {
+            if (up->size == 0)
+               png_warning(png_ptr, "Writing zero-length unknown chunk");
             png_write_chunk(png_ptr, up->name, up->data, up->size);
          }
        }
@@ -391,6 +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)
@@ -437,6 +451,9 @@ 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 */
+#ifdef PNG_SETJMP_SUPPORTED
+    volatile
+#endif
    png_structp png_ptr;
 #ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
@@ -1074,7 +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);
diff --git a/png/pngwtran.c b/png/pngwtran.c
index ac5281a8c..0372fe656 100644
--- a/png/pngwtran.c
+++ b/png/pngwtran.c
@@ -3,7 +3,7 @@
  *
  * Last changed in libpng 1.2.9 April 14, 2006
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2008 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2006 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.)
  */
diff --git a/png/pngwutil.c b/png/pngwutil.c
index 2499844df..aad54b792 100644
--- a/png/pngwutil.c
+++ b/png/pngwutil.c
@@ -1,7 +1,7 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * Last changed in libpng 1.2.20 Septhember 3, 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) 1998-2008 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
@@ -64,7 +82,7 @@ png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
 {
    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);
+   png_byte buf[8];
+
+   png_debug2(0, "Writing %s chunk, length = %lu\n", chunk_name,
+      (unsigned long)length);
    if(png_ptr == NULL) return;
 
-   /* write the length */
+   /* write the length and the chunk name */
    png_save_uint_32(buf, length);
-   png_write_data(png_ptr, buf, (png_size_t)4);
-
-   /* write the chunk name */
-   png_write_data(png_ptr, chunk_name, (png_size_t)4);
+   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);
@@ -103,8 +123,11 @@ png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
    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);
    }
 }
 
@@ -116,29 +139,12 @@ png_write_chunk_end(png_structp png_ptr)
 
    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_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);
@@ -291,7 +298,7 @@ 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));
                   png_free(png_ptr, old_ptr);
@@ -304,7 +311,8 @@ png_text_compress(png_structp png_ptr,
 
             /* 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++;
@@ -350,7 +358,7 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
    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_size_t)png_ptr->zbuf_size);
       png_free(png_ptr, comp->output_ptr[i]);
       comp->output_ptr[i]=NULL;
    }
@@ -360,7 +368,7 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
    /* 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);
@@ -380,6 +388,8 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
 #ifdef PNG_USE_LOCAL_ARRAYS
    PNG_IHDR;
 #endif
+   int ret;
+
    png_byte buf[13]; /* buffer to store the IHDR info */
 
    png_debug(1, "in png_write_IHDR\n");
@@ -494,7 +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;
@@ -523,10 +533,19 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
       png_ptr->zlib_window_bits = 15;
    if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
       png_ptr->zlib_method = 8;
-   if (deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
+   ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
       png_ptr->zlib_method, png_ptr->zlib_window_bits,
-      png_ptr->zlib_mem_level, png_ptr->zlib_strategy) != Z_OK)
+         png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
+   if (ret != Z_OK)
+   {
+      if (ret == Z_VERSION_ERROR) png_error(png_ptr,
+          "zlib failed to initialize compressor -- version error");
+      if (ret == Z_STREAM_ERROR) png_error(png_ptr,
+           "zlib failed to initialize compressor -- stream error");
+      if (ret == Z_MEM_ERROR) png_error(png_ptr,
+           "zlib failed to initialize compressor -- mem error");
        png_error(png_ptr, "zlib failed to initialize compressor");
+   }
    png_ptr->zstream.next_out = png_ptr->zbuf;
    png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
    /* libpng is not interested in zstream.data_type */
@@ -578,7 +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++)
    {
@@ -650,7 +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;
 }
 
@@ -662,7 +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;
 }
@@ -683,7 +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
@@ -698,7 +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
@@ -718,7 +738,7 @@ png_write_sRGB(png_structp png_ptr, int srgb_intent)
          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
 
@@ -779,14 +799,15 @@ png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
      }
 
    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);
+   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, name_len + 2);
+   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);
@@ -823,10 +844,11 @@ 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_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, name_len + 1);
-   png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, 1);
+   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
@@ -870,7 +892,7 @@ png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
            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);
+      png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
    }
 #endif
 
@@ -931,7 +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
 
@@ -995,7 +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
@@ -1016,7 +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;
    }
@@ -1047,7 +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
@@ -1072,7 +1095,8 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
          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)
    {
@@ -1084,7 +1108,7 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
          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)
    {
@@ -1098,7 +1122,7 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
               "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);
+      png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
    }
    else
    {
@@ -1131,7 +1155,7 @@ 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)
    {
@@ -1144,7 +1168,7 @@ png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
               "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);
+      png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
    }
    else
    {
@@ -1155,7 +1179,7 @@ png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
          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
@@ -1180,7 +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]);
@@ -1346,16 +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);
@@ -1387,6 +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;
    }
 
@@ -1404,10 +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;
@@ -1472,7 +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
@@ -1486,7 +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 || \
@@ -1496,16 +1526,17 @@ 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);
    png_free(png_ptr, new_key);
-   if (new_lang)
      png_free(png_ptr, new_lang);
 }
 #endif
@@ -1529,7 +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)
@@ -1557,21 +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;
@@ -1630,7 +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
@@ -1660,7 +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
@@ -1686,7 +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
 
@@ -1718,7 +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
 
@@ -1751,15 +1784,16 @@ png_write_start_row(png_structp png_ptr)
       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;
    }
 
@@ -1767,31 +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 */