The GIF patents have expired. There's no reason to avoid using an
external GIF library anymore. I would like to throw out our internal
GIF support, because the source files have no license information in
them. They are part of the GPLv3 blocker list.
As it turns out, the source files we are using were forked from
giflib, which is commonly used to supply GIF support (Emacs uses it,
for example). However, we've missed out on further development of
that library. The library is currently distributed with an MIT
license, so our internal GIF support is probably okay, but I'd rather
let someone else maintain the code.
This patch removes the internal GIF support code and attempts to find
and use giflib for GIF support. Lightly tested, but more feedback is
XEmacs-Patches mailing list