375462 - hang at www.bethelmaine.com/events (heavily nested float/clear)

Status: RESOLVED FIXED

(Core :: Layout, defect, P3)

Description

[Julia Reuter]

User-Agent:       Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322)
Build Identifier: Firefox 2.0.0.3

www.bethelmaine.com/events worked in the older versions of Firefox.  Now when I click on it, the URL crashes the Web site.

Reproducible: Always

Steps to Reproduce:
1. Go to www.bethelmaine.com
2. Under Visitor Center or under Business and Community, click on Events
3. 
Actual Results:  
Partial calendar may come up, but then crash.  I may get a white screen or might get the "hourglass" telling me to wait.  I can wait forever, and it will not complete loading the events calendar.

Expected Results:  
See the events calendar for the current month, be able to scroll up and down in it, and then be able to click on other months.

Comment 1

[Mats Palmgren (inactive)]

Firefox 2.0.0.3 Linux hangs w. 100% CPU.  Firefox trunk Linux too.

Looking briefly in a debugger it appears to be an infinite reflow recursion
which would eventually crash with a stack overflow.

Comment 2

[Hermann Schwab]

I checked using Seamonkey and Firefox Branch on Win98 with JS disabled and got a hang, but no crash.


Before hanging the error console was showing 2 warnings, the last one about
line 1152:    -khtml-opacity: 0.2;

http://www.bethelmaine.com/portal_css/ploneStyles0909.css

/* For ghosted elements */
.visualGhosted {
    opacity: 0.2;
    -moz-opacity: 0.2;
    -khtml-opacity: 0.2;
}

Comment 3

[Daniel Holbert [:dholbert]]

I checked using Firefox 1.5 and on Firefox Trunk, running under Linux, and I got hangs with high CPU usage, but the page eventually loaded in both cases. It took on the order of 5 min to load. (although I'm not exactly sure how long it was)

Comment 4

[Boris Zbarsky [:bzbarsky]]

I profiled this... we're spending all our time in reflow.

It looks like on trunk the performance regressed between 2004-11-25-07 and 2004-11-26-08.  

Bonsai query:  http://bonsai.mozilla.org/cvsquery.cgi?treeid=default&module=MozillaTinderboxAll&branch=HEAD&branchtype=match&dir=&file=&filetype=match&who=&whotype=match&sortby=Date&hours=2&date=explicit&mindate=2004-11-25+07&maxdate=2004-11-26+08&cvsroot=%2Fcvsroot

Fallout from bug 209694, probably?  If so, likely the same thing as bug 273293 and the things it blocks.

Comment 5

[Julia Reuter]

My programmer has fixed the problem.  Thanks for trying.
Julia

Comment 6

[Martijn Wargers (dead)]

You mean the site was changed to workaround this bug in Firefox, right?
Do you have the site/an example somewhere that still shows the bug that you could attach to the bug?

Comment 7

[Julia Reuter]

My programmer writes, "Here is a link to the old, bugy events page:

http://www.bethelmaine.com/events/index_events_bugy

   What I did was remove all of the floating elements and spaced
things out using tables instead."

Comment 8

[Mats Palmgren (inactive)]

I did crash on the original Events page (comment 1), but the URL in
comment 7 does not crash for me.  It's a bit slow to render (~15 secs)
in Firefox 2.0.0.3 and 2.0.0.4, but a trunk build is better ~3 secs.

Comment 9

[Mats Palmgren (inactive)]

Attachment: Testcase #1 (can probably be reduced further)

I now get a hang on the URL in comment 7 (100% CPU for a couple of minutes
before I killed it) using Firefox trunk, 2.0.0.4 and 1.5.0.12 on Linux.

The problem in the markup is <div style="clear: both;" /> which doesn't
close the element.  This creates a deep frame tree for the URL but we
shouldn't have this bad performance.  The testcase only has 24 of those
elements but it's still slow (it takes about 10 seconds on a fast PC).

Comment 10

[Eli Friedman]

Fixed by the patch to Bug 320378.

Comment 11

[Mats Palmgren (inactive)]

Bug 320378 was backed out.  Reopening so we don't lose track of this bug.

Comment 12

[Worcester12345]

I just tried that Bethel Maine test site, and while it wasn't necessarily speedy, I don't think it took 20 seconds either.


This is with:
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.7pre) Gecko/20070808 BonEcho/2.0.0.7pre ID:2007080804


and also with:
Build identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a8pre) Gecko/200708070303 SeaMonkey/2.0a1pre

Comment 13

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Fixed by checkin for bug 320378.

Comment 14

[Mats Palmgren (inactive)]

Crash test:
https://hg.mozilla.org/integration/mozilla-inbound/rev/1d75e6a4bb78

Comment 15

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/1d75e6a4bb78