Update to libpng 1.2.52 (rollup change only)

third_party/libpng/png.c

Index: third_party/libpng/png.c
diff --git a/third_party/libpng/png.c b/third_party/libpng/png.c
index babad71d14e7c66fcd43955720d8551be9b2473c..2ebb6f752b166b3f84373dd5d4a467ca10cbe99b 100644
--- a/third_party/libpng/png.c
+++ b/third_party/libpng/png.c
@@ -1,8 +1,8 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.2.43 [February 25, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.51 [February 6, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -17,7 +17,7 @@
 #include "png.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_2_45 Your_png_h_is_not_version_1_2_45;
+typedef version_1_2_52 Your_png_h_is_not_version_1_2_52;
 
 /* Version information for C files.  This had better match the version
  * string defined in png.h.
@@ -718,20 +718,20 @@ png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
 png_charp PNGAPI
 png_get_copyright(png_structp png_ptr)
 {
-   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
 #ifdef PNG_STRING_COPYRIGHT
       return PNG_STRING_COPYRIGHT
 #else
 #ifdef __STDC__
    return ((png_charp) PNG_STRING_NEWLINE \
-     "libpng version 1.2.45 - July 7, 2011" PNG_STRING_NEWLINE \
-     "Copyright (c) 1998-2010 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
+     "libpng version 1.2.52 - November 20, 2014" PNG_STRING_NEWLINE \
+     "Copyright (c) 1998-2014 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE);
 #else
-      return ((png_charp) "libpng version 1.2.45 - July 7, 2011\
-      Copyright (c) 1998-2010 Glenn Randers-Pehrson\
+      return ((png_charp) "libpng version 1.2.52 - November 20, 2014\
+      Copyright (c) 1998-2014 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
 #endif
@@ -750,7 +750,7 @@ png_charp PNGAPI
 png_get_libpng_ver(png_structp png_ptr)
 {
    /* Version of *.c files used when building libpng */
-   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
    return ((png_charp) PNG_LIBPNG_VER_STRING);
 }
 
@@ -758,7 +758,7 @@ png_charp PNGAPI
 png_get_header_ver(png_structp png_ptr)
 {
    /* Version of *.h files used when building libpng */
-   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+   PNG_UNUSED(png_ptr)  /* Silence compiler warning about unused png_ptr */
    return ((png_charp) PNG_LIBPNG_VER_STRING);
 }
 
@@ -766,7 +766,7 @@ png_charp PNGAPI
 png_get_header_version(png_structp png_ptr)
 {
    /* Returns longer string containing both version and date */
-   png_ptr = png_ptr;  /* Silence compiler warning about unused png_ptr */
+   PNG_UNUSED(png_ptr) /* Silence compiler warning about unused png_ptr */
 #ifdef __STDC__
    return ((png_charp) PNG_HEADER_VERSION_STRING
 #ifndef PNG_READ_SUPPORTED
@@ -1009,14 +1009,6 @@ png_check_IHDR(png_structp png_ptr,
       error = 1;
    }
 
-   if ( width > (PNG_UINT_32_MAX
-                 >> 3)      /* 8-byte RGBA pixels */
-                 - 64       /* bigrowbuf hack */
-                 - 1        /* filter byte */
-                 - 7*8      /* rounding of width to multiple of 8 pixels */
-                 - 8)       /* extra max_pixel_depth pad */
-      png_warning(png_ptr, "Width is too large for libpng to process pixels");
-
    /* Check other values */
    if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
        bit_depth != 8 && bit_depth != 16)