189503 - window motion causes X server freeze

Status: RESOLVED EXPIRED

(Core :: XUL, defect)

Description

[rjh]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20021130
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20021130

Popup windows, such as download manager, sometimes trigger X windows into a
tight internal loop when these are moved across the boundary of a Mozilla
window.  When this happens, the cursor tracking continues with the crossed arrow
cursor.  Mouse buttons and keyboard input is ignored.  Separate examination
indicates that X windows is now in a tight loop consuming all CPU cycles.

This is probably multiple bugs in multiple applications.  This only affects
Mozilla popup windows.  No other windows (Mozilla or other applications) appear
to be affected.  The window freeze is always close to the point where the popup
has crossed a Mozilla window boundary.

Killing Mozilla and Windowmaker does not cause an X recovery.

X Version: 4.2.0
Windowmaker Version: 0.80.1

Reproducible: Sometimes

Steps to Reproduce:
1.Initiate a reasonably long download with download manager popup
2.Download window begins inside the Mozilla window
3.Move download window back and forth across the boundary of the Mozilla window

Actual Results:  
Window motion freezes.  Cursor tracking continues.  Mouse button and keyboard
input is ignored.  X Server is approx. 100% CPU.

Expected Results:  
Normal window motion

I'm also informing the XFree86 developers.  Since this behavior is only
triggered by Mozilla, I suspect that it is a combination of an erroneous Mozilla
message that is then incorrectly handled by the X server and/or WindowMaker. 
Since I did not find this already reported, I suspect that WindowMaker is also
involved in some way, and the bug may be in WindowMaker.  A bug like this would
have been reported by now if it affected all of the different window managers.

Comment 1

[rjh]

Further testing reveals that this is also hardware dependent and performance. 
The bug appears on a production system.  I just configured the same software on
a different machine for further testing.  The bug is not apparent.  The key
differences between the machines is that the bug is present on an Athlon T-bird
with ATI R128 SM card.  The bug will not trigger on an Intel P4 2400 with NVidia
Riva TNT2 M64.  So far I've given it about five minutes of popup window motion.

This may be performance related.  Mozilla 1.1 can sometimes induce the bug, now
that I know what to do, but it takes several minutes of popup window wiggling. 
Mozilla 1.3a and 1.2.1 can both be induced to freeze within about 15 seconds of
window wiggling.  The test is to create a small popup window and then whip it
fully back and forth across a Mozilla main window edge as fast as I can.

Comment 2

[Sven Krohlas]

Reporter, is this still a problem with current Mozilla builds?

Comment 3

[Gervase Markham [:gerv]]

This is an automated message, with ID "auto-resolve01".

This bug has had no comments for a long time. Statistically, we have found that
bug reports that have not been confirmed by a second user after three months are
highly unlikely to be the source of a fix to the code.

While your input is very important to us, our resources are limited and so we
are asking for your help in focussing our efforts. If you can still reproduce
this problem in the latest version of the product (see below for how to obtain a
copy) or, for feature requests, if it's not present in the latest version and
you still believe we should implement it, please visit the URL of this bug
(given at the top of this mail) and add a comment to that effect, giving more
reproduction information if you have it.

If it is not a problem any longer, you need take no action. If this bug is not
changed in any way in the next two weeks, it will be automatically resolved.
Thank you for your help in this matter.

The latest beta releases can be obtained from:
Firefox:     http://www.mozilla.org/projects/firefox/
Thunderbird: http://www.mozilla.org/products/thunderbird/releases/1.5beta1.html
Seamonkey:   http://www.mozilla.org/projects/seamonkey/

Comment 4

[Gervase Markham [:gerv]]

This bug has been automatically resolved after a period of inactivity (see above
comment). If anyone thinks this is incorrect, they should feel free to reopen it.