bug#6258: create-animated-image hangs

[Juri Linkov <juri@jurta.org>]

When the delay between images in an animated GIF file is 0,
then calls for `run-with-timer' without delay hangs up.
Replacing it with `run-with-idle-timer' doesn't help.
An example of the animated GIF that hangs up is
http://en.wikipedia.org/wiki/File:Animated_glider_emblem.gif

This patch makes a short delay (0.1 sec) in this case.
Visually its speed looks the same as the speed of changing
images in Firefox when an animated GIF has no delay.

=== modified file 'lisp/image.el'
--- lisp/image.el	2010-04-02 23:28:46 +0000
+++ lisp/image.el	2010-05-24 16:01:45 +0000
@@ -684,10 +684,13 @@ (defun image-animated-p (image)
     (let* ((metadata (image-metadata image))
 	   (images (plist-get metadata 'count))
 	   (extdata (plist-get metadata 'extension-data))
-	   (anim (plist-get extdata #xF9)))
-      (and (integerp images) (> images 1)
-	   (stringp anim) (>= (length anim) 4)
-	   (cons images (+ (aref anim 1) (* (aref anim 2) 256))))))))
+	   (anim (plist-get extdata #xF9))
+	   (tmo (and (integerp images) (> images 1)
+		     (stringp anim) (>= (length anim) 4)
+		     (+ (aref anim 1) (* (aref anim 2) 256)))))
+      (when tmo
+	(if (eq tmo 0) (setq tmo 10))
+	(cons images tmo))))))
 
 \f
 (provide 'image)

-- 
Juri Linkov
http://www.jurta.org/emacs/