diff -ru4NwbB libpng-1.2.44/Makefile.am libpng-1.2.45rc01/Makefile.am
--- libpng-1.2.44/Makefile.am	2010-06-25 19:31:28.410414574 -0500
+++ libpng-1.2.45rc01/Makefile.am	2011-06-30 20:02:13.535981904 -0500
@@ -101,9 +101,10 @@
 	cp libpng-config $@
 
 libpng.sym: png.h pngconf.h
 	rm -f $@ $@.new
-	$(CPP) @LIBPNG_DEFINES@ $(CPPFLAGS) -DPNG_BUILDSYMS $(srcdir)/png.h | \
+	$(CPP) @LIBPNG_DEFINES@ $(CPPFLAGS) -DPNG_BUILDSYMS $(srcdir)/png.h $(srcdir)/$@
+	cat $(srcdir)/$@ | \
 		$(SED) -n -e \
 		's|^.*PNG_FUNCTION_EXPORT[ 	]*\([$(AN)]*\).*$$|$(SYMBOL_PREFIX)\1|p' \
 		-e 's|^.*PNG_DATA_EXPORT[ 	]*\([$(AN)]*\).*$$|$(SYMBOL_PREFIX)\1|p' \
 			>$@.new
diff -ru4NwbB libpng-1.2.44/png.h libpng-1.2.45rc01/png.h
--- libpng-1.2.44/png.h	2010-06-25 19:31:14.374271550 -0500
+++ libpng-1.2.45rc01/png.h	2011-06-30 20:01:59.125251462 -0500
@@ -1,8 +1,8 @@
 /* png.h - header file for PNG reference library
  *
  * libpng version 1.2.45rc01 - June 30, 2011
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2011 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.)
  *
  * This code is released under the libpng license (See LICENSE, below)
@@ -230,9 +230,9 @@
  *    1.2.36                  13    10236  12.so.0.36[.0]
  *    1.2.37beta01-03         13    10237  12.so.0.37[.0]
  *    1.2.37rc01              13    10237  12.so.0.37[.0]
  *    1.2.37                  13    10237  12.so.0.37[.0]
- *    1.2.45                  10    10045  12.so.0.45[.0]
+ *    1.0.45                  10    10045  12.so.0.45[.0]
  *    1.0.46                  10    10046  10.so.0.46[.0]
  *    1.2.38beta01            13    10238  12.so.0.38[.0]
  *    1.2.38rc01-03           13    10238  12.so.0.38[.0]
  *    1.0.47                  10    10047  10.so.0.47[.0]
@@ -261,8 +261,11 @@
  *    1.2.43                  13    10243  12.so.0.43[.0]
  *    1.2.44beta01-03         13    10244  12.so.0.44[.0]
  *    1.2.44rc01-03           13    10244  12.so.0.44[.0]
  *    1.2.44                  13    10244  12.so.0.44[.0]
+ *    1.2.45beta01-03         13    10245  12.so.0.45[.0]
+ *    1.0.55rc01              13    10055  10.so.0.55[.0]
+ *    1.2.45rc01              13    10245  12.so.0.45[.0]
  *
  *    Henceforth the source version will match the shared-library major
  *    and minor numbers; the shared-library major version number will be
  *    used for changes in backward compatibility, as it is intended.  The
diff -ru4NwbB libpng-1.2.44/pngconf.h libpng-1.2.45rc01/pngconf.h
--- libpng-1.2.44/pngconf.h	2010-06-25 19:31:14.383889782 -0500
+++ libpng-1.2.45rc01/pngconf.h	2011-06-30 20:01:59.134297668 -0500
@@ -1,9 +1,9 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
  * libpng version 1.2.45rc01 - June 30, 2011
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2011 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.)
  *
  * This code is released under the libpng license.
diff -ru4NwbB libpng-1.2.44/pngerror.c libpng-1.2.45rc01/pngerror.c
--- libpng-1.2.44/pngerror.c	2010-06-25 19:31:14.405023751 -0500
+++ libpng-1.2.45rc01/pngerror.c	2011-06-30 20:01:59.154710625 -0500
@@ -1,9 +1,9 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.2.41 [December 3, 2009]
- * Copyright (c) 1998-2009 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.45 [June 30, 2011]
+ * Copyright (c) 1998-2011 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.)
  *
  * This code is released under the libpng license.
@@ -86,14 +86,19 @@
 #else
 void PNGAPI
 png_err(png_structp png_ptr)
 {
+   /* Prior to 1.2.45 the error_fn received a NULL pointer, expressed
+    * erroneously as '\0', instead of the empty string "".  This was
+    * apparently an error, introduced in libpng-1.2.20, and png_default_error
+    * will crash in this case.
+    */
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_ptr, '\0');
+      (*(png_ptr->error_fn))(png_ptr, "");
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
-   png_default_error(png_ptr, '\0');
+   png_default_error(png_ptr, "");
 }
 #endif /* PNG_ERROR_TEXT_SUPPORTED */
 
 #ifdef PNG_WARNINGS_SUPPORTED
@@ -180,10 +185,15 @@
    else
    {
       buffer[iout++] = ':';
       buffer[iout++] = ' ';
-      png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
-      buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
+
+      iin = 0;
+      while (iin < PNG_MAX_ERROR_TEXT-1 && error_message[iin] != '\0')
+         buffer[iout++] = error_message[iin++];
+
+      /* iin < PNG_MAX_ERROR_TEXT, so the following is safe: */
+      buffer[iout] = '\0';
    }
 }
 
 #ifdef PNG_READ_SUPPORTED
diff -ru4NwbB libpng-1.2.44/pngmem.c libpng-1.2.45rc01/pngmem.c
--- libpng-1.2.44/pngmem.c	2010-06-25 19:31:14.423245005 -0500
+++ libpng-1.2.45rc01/pngmem.c	2011-06-30 20:01:59.172175151 -0500
@@ -441,9 +441,9 @@
  * need to allocate exactly 64K, so whatever you call here must
  * have the ability to do that.
  */
 
-png_voidp PNGAPI
+png_voidp /* PRIVATE */
 png_calloc(png_structp png_ptr, png_uint_32 size)
 {
    png_voidp ret;
 
diff -ru4NwbB libpng-1.2.44/pngrtran.c libpng-1.2.45rc01/pngrtran.c
--- libpng-1.2.44/pngrtran.c	2010-06-25 19:31:14.461091362 -0500
+++ libpng-1.2.45rc01/pngrtran.c	2011-06-30 20:01:59.208899429 -0500
@@ -1,9 +1,9 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.2.43 [February 25, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.45 [June 30, 2011]
+ * Copyright (c) 1998-2011 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.)
  *
  * This code is released under the libpng license.
@@ -675,12 +675,23 @@
 void PNGAPI
 png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
    double green)
 {
-   int red_fixed = (int)((float)red*100000.0 + 0.5);
-   int green_fixed = (int)((float)green*100000.0 + 0.5);
+   int red_fixed, green_fixed;
    if (png_ptr == NULL)
       return;
+   if (red > 21474.83647 || red < -21474.83648 ||
+       green > 21474.83647 || green < -21474.83648)
+   {
+      png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
+      red_fixed = -1;
+      green_fixed = -1;
+   }
+   else
+   {
+      red_fixed = (int)((float)red*100000.0 + 0.5);
+      green_fixed = (int)((float)green*100000.0 + 0.5);
+   }
    png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
 }
 #endif
 
@@ -1195,10 +1206,9 @@
    if (png_ptr->transformations & PNG_EXPAND)
    {
       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)
             info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
          else
             info_ptr->color_type = PNG_COLOR_TYPE_RGB;
          info_ptr->bit_depth = 8;
diff -ru4NwbB libpng-1.2.44/pngrutil.c libpng-1.2.45rc01/pngrutil.c
--- libpng-1.2.44/pngrutil.c	2010-06-25 19:31:14.474581864 -0500
+++ libpng-1.2.45rc01/pngrutil.c	2011-06-30 20:01:59.221789203 -0500
@@ -1,9 +1,9 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.2.44 [June 26, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.45 [June 30, 2011]
+ * Copyright (c) 1998-2011 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.)
  *
  * This code is released under the libpng license.
@@ -1811,8 +1811,16 @@
       png_crc_finish(png_ptr, length);
       return;
    }
 
+   /* Need unit type, width, \0, height: minimum 4 bytes */
+   else if (length < 4)
+   {
+      png_warning(png_ptr, "sCAL chunk too short");
+      png_crc_finish(png_ptr, length);
+      return;
+   }
+
    png_debug1(2, "Allocating and reading sCAL chunk data (%lu bytes)",
       length + 1);
    png_ptr->chunkdata = (png_charp)png_malloc_warn(png_ptr, length + 1);
    if (png_ptr->chunkdata == NULL)
diff -ru4NwbB libpng-1.2.44/pngwrite.c libpng-1.2.45rc01/pngwrite.c
--- libpng-1.2.44/pngwrite.c	2010-06-25 19:31:14.515866839 -0500
+++ libpng-1.2.45rc01/pngwrite.c	2011-06-30 20:01:59.262090112 -0500
@@ -1,9 +1,9 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.2.42 [January 3, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.45 [June 30, 2011]
+ * Copyright (c) 1998-2011 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.)
  *
  * This code is released under the libpng license.
@@ -294,8 +294,9 @@
          int keep = png_handle_as_unknown(png_ptr, up->name);
          if (keep != PNG_HANDLE_CHUNK_NEVER &&
             up->location && (up->location & PNG_HAVE_PLTE) &&
             !(up->location & PNG_HAVE_IDAT) &&
+            !(up->location & PNG_AFTER_IDAT) &&
             ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
             (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
          {
             png_write_chunk(png_ptr, up->name, up->data, up->size);
diff -ru4NwbB libpng-1.2.44/projects/xcode/libpng.xcodeproj/project.pbxproj libpng-1.2.45rc01/projects/xcode/libpng.xcodeproj/project.pbxproj
--- libpng-1.2.44/projects/xcode/libpng.xcodeproj/project.pbxproj	2010-06-25 19:31:15.672252821 -0500
+++ libpng-1.2.45rc01/projects/xcode/libpng.xcodeproj/project.pbxproj	2011-06-30 20:02:00.398783994 -0500
@@ -221,9 +221,9 @@
 			buildSettings = {
 				COPY_PHASE_STRIP = NO;
 				DYLIB_COMPATIBILITY_VERSION = 3;
 				DYLIB_CURRENT_VERSION = 3;
-				FRAMEWORK_VERSION = 1.2.44;
+				FRAMEWORK_VERSION = 1.2.45rc01;
 				GCC_PRECOMPILE_PREFIX_HEADER = NO;
 				GCC_PREFIX_HEADER = "";
 				INFOPLIST_FILE = Info.plist;
 				INSTALL_PATH = "@executable_path/../Frameworks";
@@ -239,9 +239,9 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				DYLIB_COMPATIBILITY_VERSION = 3;
 				DYLIB_CURRENT_VERSION = 3;
-				FRAMEWORK_VERSION = 1.2.44;
+				FRAMEWORK_VERSION = 1.2.45rc01;
 				GCC_PRECOMPILE_PREFIX_HEADER = NO;
 				GCC_PREFIX_HEADER = "";
 				INFOPLIST_FILE = Info.plist;
 				INSTALL_PATH = "@executable_path/../Frameworks";