Updates the PNG library to 1.2.37, enables some functionality for O3D

third_party/libpng/pngrio.c

Index: third_party/libpng/pngrio.c
===================================================================
--- third_party/libpng/pngrio.c	(revision 18910)
+++ third_party/libpng/pngrio.c	(working copy)
@@ -1,7 +1,7 @@
 
 /* pngrio.c - functions for data input
  *
- * Last changed in libpng 1.2.36 [May 7, 2009]
+ * Last changed in libpng 1.2.37 [June 4, 2009]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -20,10 +20,11 @@
 #if defined(PNG_READ_SUPPORTED)
 
 /* Read the data from whatever input you are using.  The default routine
-   reads from a file pointer.  Note that this routine sometimes gets called
-   with very small lengths, so you should implement some kind of simple
-   buffering if you are using unbuffered reads.  This should never be asked
-   to read more then 64K on a 16 bit machine. */
+ * reads from a file pointer.  Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered reads.  This should never be asked
+ * to read more then 64K on a 16 bit machine.
+ */
 void /* PRIVATE */
 png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
@@ -36,16 +37,18 @@
 
 #if !defined(PNG_NO_STDIO)
 /* This is the function that does the actual reading of data.  If you are
-   not reading from a standard C stream, you should create a replacement
-   read_data function and use it at run time with png_set_read_fn(), rather
-   than changing the library. */
+ * not reading from a standard C stream, you should create a replacement
+ * read_data function and use it at run time with png_set_read_fn(), rather
+ * than changing the library.
+ */
 #ifndef USE_FAR_KEYWORD
 void PNGAPI
 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
    png_size_t check;
 
-   if (png_ptr == NULL) return;
+   if (png_ptr == NULL)
+      return;
    /* fread() returns 0 on error, so it is OK to store this in a png_size_t
     * instead of an int, which is what fread() actually returns.
     */
@@ -61,7 +64,7 @@
       png_error(png_ptr, "Read Error");
 }
 #else
-/* this is the model-independent version. Since the standard I/O library
+/* This is the model-independent version. Since the standard I/O library
    can't handle far buffers in the medium and small models, we have to copy
    the data.
 */
@@ -76,7 +79,8 @@
    png_byte *n_data;
    png_FILE_p io_ptr;
 
-   if (png_ptr == NULL) return;
+   if (png_ptr == NULL)
+      return;
    /* Check if data really is near. If so, use usual code. */
    n_data = (png_byte *)CVT_PTR_NOCHECK(data);
    io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
@@ -121,25 +125,27 @@
 #endif
 
 /* This function allows the application to supply a new input function
-   for libpng if standard C streams aren't being used.
-
-   This function takes as its arguments:
-   png_ptr      - pointer to a png input data structure
-   io_ptr       - pointer to user supplied structure containing info about
-                  the input functions.  May be NULL.
-   read_data_fn - pointer to a new input function that takes as its
-                  arguments a pointer to a png_struct, a pointer to
-                  a location where input data can be stored, and a 32-bit
-                  unsigned int that is the number of bytes to be read.
-                  To exit and output any fatal error messages the new write
-                  function should call png_error(png_ptr, "Error msg").
-                  May be NULL, in which case libpng's default function will
-                  be used. */
+ * for libpng if standard C streams aren't being used.
+ *
+ * This function takes as its arguments:
+ * png_ptr      - pointer to a png input data structure
+ * io_ptr       - pointer to user supplied structure containing info about
+ *                the input functions.  May be NULL.
+ * read_data_fn - pointer to a new input function that takes as its
+ *                arguments a pointer to a png_struct, a pointer to
+ *                a location where input data can be stored, and a 32-bit
+ *                unsigned int that is the number of bytes to be read.
+ *                To exit and output any fatal error messages the new write
+ *                function should call png_error(png_ptr, "Error msg").
+ *                May be NULL, in which case libpng's default function will
+ *                be used.
+ */
 void PNGAPI
 png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
    png_rw_ptr read_data_fn)
 {
-   if (png_ptr == NULL) return;
+   if (png_ptr == NULL)
+      return;
    png_ptr->io_ptr = io_ptr;
 
 #if !defined(PNG_NO_STDIO)