Re: XEmacs and 1x1 gif images

On Sat, 31 Dec 2011 12:14:39 +0100 Robert Pluim <rpluim(a)gmail.com&gt; wrote: It looks like the gif image is good... except it is missing the terminator byte (0x3b). It is such a HUGE gif, they are probably trying to save space ;) All the readers I tried handled this gracefully, except XEmacs. Even Emacs handled it. I looked quickly at XEmacs 21.4 and DGifSlurp basically does this: do { GetRecordType switch (type) process } while (RecordType != TERMINATE_RECORD_TYPE); Since there is no terminate byte, GetRecordType tries to read the next byte and fails. I have some gif knowledge, but I am no expert so take this with a lump of salt (unless you are on a salt reduced diet). But it looks like this is done to get around not keeping track of the gif version. So instead of doing what I would consider normal: read header if gif89a read extension header read image block header read image blocks read terminator XEmacs does this: read header Slurp (as shown above) It seems that the loop is only to handle the fact that the extension header may or may not exist. One solution is to check for EOF before calling GetRecordType, since it looks like the lack of a terminator is not considered fatal in practice. Cheers, Sean _______________________________________________ XEmacs-Beta mailing list XEmacs-Beta(a)xemacs.org http://lists.xemacs.org/mailman/listinfo/xemacs-beta