286962 - once-playing gif does not play again when reloaded over css

Status: RESOLVED INVALID

(Firefox :: General, defect)

Description

[Lars Schöning]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050225 Firefox/1.0.1
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050225 Firefox/1.0.1

When using a css background-image and having a hover on a once-playing gif, this
does not reset causing the gif not to play the next time again.

Reproducible: Always

Steps to Reproduce:
1. Making a css with a default and hover on a once (in contrast to infinite)
running gif.

e.g.:

a { backgound-image:url(foo.jpg); }
a:hover { background-image:url(once-playing.gif) }
Actual Results:  
The gif plays only on the first mouse over, the next hovers only show the last
frame of the gif and don't play again.


Expected Results:  
The gif should have played once on each mouseover (hover) effect.

Comment 1

[Gabriel Sjoberg]

I would argue that this is actually appropriate behavior.  After all, the .gif
is only supposed to play once per load, and it's only loaded once.

As a fix, I suggest you put a mouseover that reloads the element on mouseout.

Barring other debate (which would be mostly aesthetic, I'm sure), this bug
should be marked INVALID.

Comment 2

[Hermann Schwab]

(In reply to comment #1)
> I would argue that this is actually appropriate behavior.  After all, the .gif
> is only supposed to play once per load, and it's only loaded once.
> 
> As a fix, I suggest you put a mouseover that reloads the element on mouseout.

Don't think that will be working, see testcases loading a 3 times rotating gif:
Bug 304150 GIF animation starts before page has fully loaded

Attachment 203977 [details] loads gif from bugzilla server, always rotating on reload 
Attachment 203983 [details] loads gif from original server, sometimes rotating on reload

difference: HTTPheaders returned from loading the gif
the bugzilla server acknowledges HTTP/1.x 200 OK
the original server acknowledges HTTP/1.x 304 Not Modified

Comment 3

[Samuel Sidler (old account; do not CC)]

This is really just a different form of bug 129986, I think. Or, possibly, it's because of how image.animation_mode is set. Either way, this bug is invalid (or a dupe). I'm going to go with invalid.