Re: XEmacs and 1x1 gif images

On Sun, 1 Jan 2012 13:25:55 +0100 Robert Pluim <rpluim(a)gmail.com&gt; wrote: > In 21.5, we use an external giflib, so we'd have to move the guts of > Slurp into our codebase, with the modification you suggest. I'm not > sure how desirable that is. Ok, here is another idea. I tested with with XEmacs 21.5.31. We change gif_read_from_memory to handle this specific case:

static int gif_read_from_memory (GifFileType *gif, GifByteType *buf, int size) {  gif_memory_storage *mem = (gif_memory_storage *) gif->UserData;  if (size > (mem->len - mem->index)) {    /* Hack to handle a gif file that is missing the terminator byte. */    if (size == 1 && mem->len > 1 && mem->bytes[mem->len - 1] != 0x3b) {      *buf = 0x3b;      mem->len = 0;      return 1;    } else      return -1;  }  memcpy (buf, mem->bytes + mem->index, size);  mem->index = mem->index + size;  return size; } Since it is short, I added the entire routine. I just added the if block. Since the UserData is setup once in gif_instantiate and only used in gif_read_from_memory, it is safe to mess with the len. I did a quick check to see that it handled the case where the terminator was missing, but still caught some other random truncations as errors.