142052 - Animated gif over expanded gif in span sets cpu to 100%

Status: RESOLVED WORKSFORME

(Core :: Graphics: ImageLib, defect)

Description

[ejohnson0547]

I have a html page which has an 1x1 pixel gif inside a span, expanded to fill
the whole page.  Then there is also an animated gif on the page.  When these two
are together, it causes the cpu to max out at 100%, and causes the mouse to move
very slowly.  This actually came from a spam email originally, but I cut out all
the irrelevant stuff.  IE displays it just fine without any spiking of the cpu.
 I know this may be bad html coding, but the last thing I want is for spam to be
able to render Mozilla helpless.
I will attach the html page and the two gif images.

I am using build 2002050304.

Comment 1

[ejohnson0547]

Attachment: test html page

Comment 2

[ejohnson0547]

Attachment: 1x1 gif

Comment 3

[ejohnson0547]

Attachment: animated gif

Comment 4

[Jason Tatem]

I have also seen this same problem in RC1, RC2, and RC3.  One interesting
side-note...if another window is the active window, with the Mozilla window
still visible elsewhere on the screen, Mozilla will render the animated gifs
properly and *not* spike the CPU.  Mozilla only spikes the CPU when it becomes
the active window.  Doesn't affect functionality much, but it does get
annoying...the pages that trigger it most often for me are those generated by
the Big Brother network monitoring system, which uses an expanded image for the
background, and small animated gifs to indicate varying degrees of system status.

Comment 5

[Jason Tatem]

Noted today (under RC3) that switching to a window displaying a page with a
small gif expanded as the background, even without other images (animated or
not), causes a CPU usage spike.  Switching to such a window takes around 1.5
seconds, whereas switching to windows displaying other pages is near
instantaneous.  The page in question doesn't have a lot of fancy HTML or
anything...I'll upload a page and test image shortly.

Comment 6

[Jason Tatem]

Attachment: Test page using expanded background image and no other images

Comment 7

[Jason Tatem]

Attachment: Background image for test page

Comment 8

[Jason Tatem]

Problem still present in 1.0 release.  Also noted that issue seems heavily tied
to the size of the window...the larger the window, the longer the CPU spike. 
Running with maximized windows on a 1280x1024 display really shows the problem well.

Comment 9

[R.K.Aa.]

Reporter: Are you still seeing this bug in recent builds?

Comment 10

[ejohnson0547]

Yes I am still seeing this bug using latest build number 2002120308.
WinNT 4, PIII 650 MHz, 256MB ram, no other applications running.

Comment 11

[Andrew Schultz]

worksforme with linux trunk 20030713 (Mozilla did not use measurable CPU)

ejohnson0547: can you still reproduce this problem?  if not, please mark WORKSFORME.