--- vultures/vultures_gfl.c.libpng 2008-07-16 08:59:01.000000000 -0500
+++ vultures/vultures_gfl.c 2012-01-29 00:08:20.845880660 -0600
@@ -22,12 +22,17 @@
#define PNG_BYTES_TO_CHECK 4
+struct readbuff {char *buff; unsigned int len;};
static void vultures_png_read_callback(png_structp png_ptr, png_bytep area, png_size_t size)
{
- void *mem = png_ptr->io_ptr;
- memcpy(area, mem, size);
- png_ptr->io_ptr = (mem + size);
+ unsigned int readlen;
+ struct readbuff *readfrom = (struct readbuff *)png_get_io_ptr(png_ptr);
+ readlen = (readfrom->len > size) ? size : readfrom->len;
+ memcpy(area, readfrom->buff, readlen);
+ size = readlen;
+ readfrom->len -= readlen;
+ readfrom->buff += readlen;
}
/*--------------------------------------------------------------------------
@@ -45,6 +50,7 @@
int bit_depth, color_type, row;
png_bytep * row_pointers = NULL;
SDL_Surface *img, *convert;
+ struct readbuff readfrom;
/* vultures_load_surface converts everything to screen format for faster blitting
* so we can't continue if we don't have a screen yet */
@@ -55,6 +61,9 @@
if (!srcbuf)
return NULL;
+ if (buflen < PNG_BYTES_TO_CHECK)
+ return NULL;
+
img = NULL;
/* memory region must contain a png file */
@@ -72,10 +81,13 @@
goto out;
/* Set up error handling */
- if (setjmp(png_ptr->jmpbuf))
+ if (setjmp(png_jmpbuf(png_ptr)))
goto out;
- png_set_read_fn(png_ptr, (char *)srcbuf, vultures_png_read_callback);
+ readfrom.buff = (char *)srcbuf;
+ readfrom.len = buflen;
+
+ png_set_read_fn(png_ptr, &readfrom, vultures_png_read_callback);
/* Read PNG header info */
png_read_info(png_ptr, info_ptr);
@@ -93,8 +105,9 @@
png_set_gray_to_rgb(png_ptr);
/* add an opaque alpha channel to anything that doesn't have one yet */
- png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
- info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+ if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_RGB ||
+ png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_GRAY)
+ png_set_add_alpha(png_ptr, 0xff, PNG_FILLER_AFTER);
/* get the component mask for the surface */
if ( SDL_BYTEORDER == SDL_LIL_ENDIAN )