User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4b) Gecko/20030507 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4b) Gecko/20030507 It seems that a display library bug gets triggered when there is just enough data in the message list window to cause the vertical scrollbar to appear/disappear. Mozilla gets caught in some kind of repaint loop, trying to resize itself. I've seen this in both Windows 2k and XP. I also saw the same behavior in the Calendar add-on. Reproducible: Always Steps to Reproduce: 1.Fill up the message list window 2.Resize the browser to the point where the message window vertical scrollbar either appears or disappears 3. Actual Results: Message list and message preview windows fluttered endlessly until you resized the browser.

If I click on the "View" link near the bottom of this page: http://www.xulplanet.com/tutorials/xultu/trees.html I get a flickering as the two panes get resized back and forth. I think it is a related bug. If I shrink the window that pops up to an even smaller size, mozilla pegs the CPU at 100%. This bug may be a dupe of bug #131733 or bug #143646 or bug #212249 or bug #213554, or is at least related to them...

have an uptick of reports on this showing up in feedback on some mozilla adminstrative aliases.. From: Mike Perry <mperryrep@charter.net> Date: Fri, 29 Aug 2003 10:17:21 -0700 Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 can you tell how to fix the up and down jittering of the e mail? i like the system but can't read e mail unless i put it on full screen. thanks ------------------------------------------------------- carmen-hermida@mindspring.com 8/27/2003 10:17 AM Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4) Gecko/20030624 Why does my lower e-mail window jump and flutter to the point of dizzyiness? At first I thought it was a purposeful big lizard dance but no, it is the whole window and not just the logo. Totally annoying. Carmen

if we can figure out how to make this go away might be a good one for 1.5 final..

look at bug 201460 comment 6 for a fix from neil.parkwaycc.co.uk Bug 201460 [Fix] Horizontal splitter vibrating by 1 char height (estimated) There is a lot of info about similar bugs, some reproducible at certain computers. This bug was spammed by one commenter, but the rest is readable. Bug 216708 Horizontal splitter vibrating by 1 line height reproducible for me at one website with two very different computers, Celeron 333, 96 MB, Windows98, 8 MB SiS6326 grafics card, 800x600 Athlon 1500, 512MB, Windows98SE, 32 MB nForce integrated grafics.

I'm wondering if this might actually be hitting a bug in a Windows low-level display library. Reason: I haven't updated my T-bird in about three months but I haven't seen a reoccurence of this problem in at least a month. I used to be able replicate it easily just by resizing the message summary window to the pivot point where the vertical scrollbar would appear/disappear. Now I can't. What has happened over the past couple of months though are several XP updates. Not saying that's the problem, just suggesting a possibility.

confirming. I can easily reproduce this on http://www.xulplanet.com/tutorials/xultu/examples/findfile/findfile-trees.xul, but with the classic skin. there's a whole bunch of dups on this, but luckily neil has a patch floating around.

confirm

another way to reproduce this: 1) classic skin, new profile 2) launch mail, don't resize the window 3) create 8 or so draft messages 4) select the draft folder 5) delete a message at a time, twice (to get to 6) it should start flickering. I don't think this is a problem for the modern skin.

yes, this is classic only. now on to test neil's patch.

another related bug: http://bugzilla.mozilla.org/show_bug.cgi?id=128809 I think that bug was designed to help address problems like this.

neil's patch doesn't fix it for me. but talking to bryner, he had some ideas. if we disable nsITheme support for native scrollbars this goes away. that explains why we see this in classic and not modern. note, the http://www.xulplanet.com/tutorials/xultu/trees.html problem is also reproducable in firebird (on win32)

as a data point, for the mail problem (which is with a vertical scrollbar), it doesn't happen if I disable native theme support for NS_THEME_SCROLLBAR_THUMB_VERTICAL. (the xulplanet case is a horizonal scrollbar.)

this is a dupe of bug 201379. not going to mark it, because this has a patch, but the other bug is where all the other dupes, votes, and ccs have gone. This bug is also in the wrong component.

it's a dup, and that patch doesn't work for me. see http://bugzilla.mozilla.org/show_bug.cgi?id=201379#c36 for bryner's description of what he thinks is going on. *** This bug has been marked as a duplicate of 201379 ***

verified.