96803 - Transparent GIFs sometimes turn black (bad ATI drivers)

Status: RESOLVED DUPLICATE of bug 104992

(Core :: Layout, defect)

Description

[mgueury]

Try the testcase and scroll in the page.
At the begin, all is well rendered, but sometimes when you scroll,
the background is shown black.

To reproduce, try to scroll such that you hide and show and hide
the icons at the top of the page. Sometimes, it comes back all 
blacks, sometimes you have small black dots.

Comment 1

[mgueury]

Attachment: Testcase with a part of page of Oracle Portal

Comment 2

[mgueury]

Seen in Mozilla 0.93

Comment 3

[mgueury]

I have simplifed the testcase to something like this.

<TABLE background="tranparent.gif">
  Some text
</TABLE>

If you scroll up and down, more or less fast, you can see the problem with a
single transparent gif.

Comment 4

[mgueury]

Attachment: Very simplified testcase

Comment 5

[mgueury]

You can also see the bug by refreshing a lot of time the page. In my case, it
happens 1 times on 20.

Comment 6

[karnaze (gone)]

Reassigning to dcone.

Comment 7

[Chris Petersen]

I can't download the attached test cases. Reporter, please attach them as
seperate items ( text/html and image/gif).

Comment 8

[mgueury]

Attachment: Testcase part 1/2

Comment 9

[mgueury]

Attachment: Testcase part 2/2

Comment 10

[mgueury]

Testcase uploaded in 2 parts.
It still happens with Mozilla 0.94

Comment 11

[Adin Aronson]

The problem of GIF images getting messed up when scrolling them off and on
screen has been happening to me too. Check out MozillaZine
(http://www.mozillazine.org/build_comments/) the top images (the MozillaZine at
the top left and blimp at the top right) get screwed up.

Comment 12

[mgueury]

The problem is still present in Mozilla 1.0 rc1... (NT)

Comment 13

[Basil Fritts]

I'm seeing a similar problem with PNGs that have transparency set. See bug
146202. Could they be related?

Comment 14

[Adin Aronson]

I just downloaded Netscape 7.0 Preview Release 1 and it shows the gifs
perfectly. Do they use a different rendering engine?

Comment 15

[Stephan Golux]

Still completely messed up in RC3 (2002052306) - no change seen.  Again, for
some reason, the problem goes away completely if JAVA (1.4) is up and running,
even if the window in question has no JAVA applets in it.

Comment 16

[Ian Neal]

Related to bug 101907 , bug 104992 or bug 111176 ?

Comment 17

[mgueury]

The problem still happens in Mozilla 1.0.

I have read the other bugs. And it looks like duplicates of this one.
Interesting is that they all explains that it is a problem with
graphics accelaration in Windows - one for ATI, one for S3 Savage

I use a S3 Savage on Windows 2000.

So, I did the following test: 
- Windows + Mozilla 1.0                                  -> Bad
- Linux   + Mozilla 1.0                                  -> OK 
- Windows + Mozilla 1.0 + disabled hardware acceleration -> OK !
  (I decreased the acceleration just of 1 step)

Comment 18

[Stephan Golux]

Taking the idea posited in #17, I reduced my ATI graphics acceleration.  One
step was not enough, I had to take it down two, and then the problem seemed to
go away.  However, I do not think the problem is only in acceleration.  There
seem to be other factors.  In my case, if JAVA (1.4) is running, things are fine
even with full acceleration.  And both Opera and IE work fine at full
acceleration.  I do remember a similar problem with Netscape 4.7 (which had, I
believe, a completely different graphics engine) but which cropped up
intermittently -- this problem with Mozilla is completely repeatable.

Comment 19

[Andrew Wilson]

Using an ATI All in wonder Pro I get the same effect as well.  The effect is
worse on the graphics on the Mozilla toolbar. Back/forward etc have black
backgrounds for me.  Dropping video card to 24bit solved the problem.  Sounds
more like a problem with ATI's buggy drivers.  However the problem isnt as bad
in Netscape.  Usually only on animated gifs and it's toolbar has always been fine.

Comment 20

[Daniel Herring]

My system:
Windows 98, ATI XPert 98, Mozilla 1.1 build #20020826

After reading comment #19, I too dropped colors from "32-bit" to "24-bit".
Problem fixed, with "full acceleration".

Could this hint be added to the "Release Notes/Known Bugs/Navigator" section?

Comment 21

[djk]

FYI, I am running at 24bit with an ATI Rage Pro card on w98, and had problems
until I knocked the acceleration down 2 notches.

Comment 22

[Christopher Hoess (gone)]

*** This bug has been marked as a duplicate of 104992 ***