304150 - GIF animation starts before page has fully loaded.

Status: RESOLVED WONTFIX

(Core :: Graphics: ImageLib, defect)

Description

[Dwight Brown]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.10) Gecko/20050716 Firefox/1.0.6
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.10) Gecko/20050716 Firefox/1.0.6

If a website uses an animated GIF the animation will begin before the page has
fully loaded.  I assume the animation simply starts immediately after the image
file has loaded.

This may be related to bug <a
href="https://bugzilla.mozilla.org/show_bug.cgi?id=286962">#286962</a> as well
because animations that are non-looping will not restart when the page is refreshed.

IE and Opera do not have this behavior.

Reproducible: Always

Steps to Reproduce:
1. Load a page that utilizes animated GIFs
2. You will see the animations start before page loading is done

Actual Results:  
Animation starts before page loading is done.

Expected Results:  
Animations should start/restart once page loading is Done and not before.

Comment 1

[Aaron Slunt]

WFM Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b4) Gecko/20050810
Firefox/1.0+ ID:2005081004

Reporter, please try to reproduce this bug with a recent nightly build.

ftp://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk

Comment 2

[Hermann Schwab]

confirming:
Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.8b4) Gecko/20050810 Firefox/1.0+
Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.8b4) Gecko/20050808 SeaMonkey/1.0a

The logo is turning three times and the stops, while the page is still loading.
AThlon XP1600+, DSL

Comment 3

[Hermann Schwab]

the logo, top left:
http://weigandomega.improvementroad.com/testcase/residential/logo-spinning.gif

Comment 4

[Boris Zbarsky [:bzbarsky]]

I believe this is by-design and desired behavior -- you don't want to have to wait on that really slow ad in the bottom of the page to load before the page becomes usable...

Comment 5

[Hermann Schwab]

(In reply to comment #4)
> I believe this is by-design and desired behavior -- you don't want to have to
> wait on that really slow ad in the bottom of the page to load before the page
> becomes usable...

Right so, but not what I see:
The banner consist of different slow loading parts, the rotating gif finishes loading early, starts rotating, rotates three and a half times before stopping, and the rest ist still loading. I'm here on ISDN 8 kbyte/sec.
All loaded, I start a reload, see the loading progress growing, while the page is still unchanged. Then near the end of loading, mostly the content area of the page is redrawn, sometimes the banner area also, but never the gif starts rotating.

http://weigandomega.improvementroad.com/testcase/residential/logo-spinning.gif
If I load the logo in a new tab, it doesn't spin at all.

I'll attach a testcase in a moment. If it loads the image from my local disc, the image rotates. If it loads the image from the server, the image doesn't rotate. Image put as data: in the URLbar rotates.

I don't know if animation of a gif is specified by time or by loopcount or both, in each case the animation here stops after a few turns, on my slow Celeron 333 I saw maybe 3 like told in comment 2.

Comment 6

[Hermann Schwab]

Attachment: logo-spinning.gif

Comment 7

[Hermann Schwab]

Attachment: minimal testcase

Attachment 293974 [details] [diff] spins if reloaded.
This attachment loaded locally loads the spinning logo from remote, did work when loaded from the local disk and gif was remote or local.

Comment 8

[Hermann Schwab]

Attachment: same testcase using image from original server

Comment 9

[Hermann Schwab]

Attachment: HTTPheaders for testcases, commented

I used extension HTTPheaders to get the headers.
1st pair is HTML from bugzilla server, image from bugzilla server.
2nd pair is HTML from bugzilla server, image from original server.

When bugzilla server acknowledges HTTP/1.x 200 OK for the image, the image is rotating.
If original server acknowledges HTTP/1.x 304 Not Modified for the image, no rotation is seen.
Using the original server the image sometimes rotates on reload, the bugzilla image always rotates on reload.

Comment 10

[Hermann Schwab]

Attachment: HTTP headers commented

1st pair is minimized testcase, loding HTML and image from bugzilla server, both give HTTP/1.x 200 OK and the image rotes.
2nd pair is HTML from bugzilla and image from the original server, sometimes  the image acknowledges HTTP/1.x 304 Not Modified and the the image doesn't rotate.

Steps to repeat: simply reload
1st testcase the image always rotates, 2nd testcase only sometimes.

Comment 11

[Boris Zbarsky [:bzbarsky]]

Comment 5 and later are not this bug, but the bug on animation being done in the shared part of the image in imagelib...

Comment 12

[Chris Lord [:cwiiis]]

I'm marking this as WONTFIX with regards to the comment #4. Comments #5 and onwards appear to be talking about a different bug. If this is the case, it should be filed as a new bug.

Please re-open this bug if you think I've made a mistake, and my apologies if so.