Bug 649475

Summary: corrupted text when scrolling
Product: [Fedora] Fedora Reporter: Tom Horsley <horsley1953>
Component: firefoxAssignee: Gecko Maintainer <gecko-bugs-nobody>
Status: CLOSED RAWHIDE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: low    
Version: 14CC: gecko-bugs-nobody, stransky
Target Milestone: ---Keywords: Triaged
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2011-12-09 10:27:07 UTC Type: ---
Regression: --- Mount Type: ---
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Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
screenshot of shredded firefox window none

Description Tom Horsley 2010-11-03 19:40:17 UTC 
Description of problem:

Firefox in my newly installed fedora 14 x86_64 system with a RV610 radeon card,
text in an area of the screen that is partially overlapped by another window
is completely shredded when I scroll the firefox main window. (I'll attach
a screen shot). On the same hardware running fedora 13 I've never had this
happen. I submit this as a firefox bug rather than a radeon driver bug
because of the other thing that happens: When I move the cursor out of the
firefox window and it loses focus, the shredded text gets redrawn correctly.
That makes me believe firefox is trying to be way too clever processing
redraw events.

Version-Release number of selected component (if applicable):
firefox-3.6.12-1.fc14.x86_64
xorg-x11-drv-ati-6.13.1-0.3.20100705git37b348059.fc14.x86_64


How reproducible:

Seems to happen pretty consistently.

Steps to Reproduce:
1.see above
2.
3.
  
Actual results:
shredded text

Expected results:
correctly redrawn text as it scrolls out from under another window

Additional info:
The ati card is:
01:00.0 VGA compatible controller: ATI Technologies Inc RV610 video device [Radeon HD 2400 PRO]
Comment 1 Tom Horsley 2010-11-03 19:42:11 UTC 
Created attachment 457562 [details]
screenshot of shredded firefox window
Comment 2 Tom Horsley 2010-11-04 13:10:11 UTC 
More evidence that this if firefox, not radeon driver: If I look at the
same page in konqueror and overlap the windows the same way, text that
scrolls out from under the xterm is drawn perfectly by konqueror, only
firefox seems to want to shred it.

I also tried this with a brand new user so no leftover ~/.mozilla nonsense
could have been inherited from the old /home directory I restored, but the
text shredding was the same.

I briefly rebooted into fedora 13 and confirmed that I do not see the
same shredding when I setup the same window overlap and scrolling.
Comment 3 Martin Stransky 2010-11-04 14:17:23 UTC 
It's known issue already fixed in upcoming Firefox 4.
Comment 4 Tom Horsley 2010-11-07 03:33:53 UTC 
Just curious, is there a bugzilla or patch or something somewhere that
points to this known issue fix? All I can find when searching is more reports
of similar bugs like this one:

https://bugzilla.mozilla.org/show_bug.cgi?id=576795
Comment 5 Martin Stransky 2010-11-08 07:44:21 UTC 
You need to search for gfx/layer bugs, the layer code was heavily updated in ff4 because of a new layer acceleration model and I guess the fix of this but is a side effect of it.
Comment 6 Tom Horsley 2010-11-29 13:28:33 UTC 
This definitely appears to be another instance of cairo changes screwing
with firefox (just like bug 628331). If I run the firefox packaged
by mozilla from firefox-3.6.12.tar.bz2 which (rumor has it) has its own cairo
lib, the shredded text problem does not appear.
Comment 7 Tom Horsley 2011-01-04 12:17:34 UTC 
FYI: The xulrunner-1.9.2.13-5.fc14.x86_64 just added to updates-testing for
bug 628331 does not fix this corrupted text issue.
Comment 8 Martin Stransky 2011-12-09 10:27:07 UTC 
Should be fixed on Fedora 15 and newer.