368394 - FF hangs when handed a stylesheet that leaves no room for the text

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Gordon Schumacher]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1    or    Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.1) Gecko/20060601 Firefox/2.0.0.1 (Ubuntu-edgy)

I am afraid I am too tired to hack through the CSS at this point - I'm not very familiar with it - but I see this with one particular style in LiveJournal, when the comment depth reaches a certain level.  I have made a dummy entry in my journal to reproduce it when viewed with the proper style, and I should be able to hand-hack the HTML and post it as an attachment.

Basically what happens is that as the comments get deeper-nested, the left margin moves closer to the right margin until it presumably no longer leaves any room for text at all.

Reproducible: Always

Steps to Reproduce:
Here are the LiveJournal settings to configure this style:
Journal menu->Edit journal style
Basics tab->Style: S2
Look and feel tab->Layout: Style Contest
Look and feel tab->Themes: Magic Paper

http://stat.livejournal.com/sixhtml/themes/stylecontest/magic_paper/magic-book.css is the stylesheet which ultimately gets selected to display the page.
Actual Results:  
FF locks shut, completely unresponsive.

Expected Results:  
An error?  Reflowing the page?  How should this get handled??  Yuck, bad design.

Comment 1

[Mats Palmgren (inactive)]

I don't understand how to perform the steps to reproduce.
Could you make a static HTML page which includes the correct stylesheet
and upload it here please? (use the "Add an attachment" link) Thanks.

Comment 2

[Gordon Schumacher]

Attachment: HTML of page that crashes Firefox

Sorry about that, I fully intended to do that the next morning but got interrupted by family crisis stuff...

Here it is.

FWIW I can add one more revision on which this crashes:
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.9) Gecko/20061206 Firefox/1.5.0.9

Comment 3

[Mats Palmgren (inactive)]

I tested Firefox 1.5.0.9, 2.0.0.1 and trunk on both Windows XP and Linux.
It's slow but does not crash or hang indefinitely. The initial layout takes
about 20 sec on a high-end PC.

Comment 4

[Gordon Schumacher]

Aha, that would do it; the Linux machine I tested on was a 1GHz P3 laptop, and the Windows box was an Athlon that I believe is <2GHz.  IOW it looked like indefinite from where I sat - I know that on the Linux box I left it for more than a couple of minutes at one point.

Interestingly, Konqueror chokes somewhat - it's very slow to render - but it recovers in a reasonable amount of time on the P3 box.  IE6 appears to handle it okay.

Comment 5

[Oleg Romashin (:romaxa)]

2x2 3.60GHz, 4Gb Ram,  Attachment loading = ~135 sec.

#0  0xa6b86b2f in nsGetterAddRefs<nsIFontMetrics>::operator* (this=0xafea4438) at ../../../dist/include/xpcom/nsCOMPtr.h:1409
#1  0xa7251742 in nsThebesRenderingContext::SetFont (this=0x8521608, aFont=@0xa3f3ca50, aLangGroup=0x83212f0)
    at mozilla/gfx/src/thebes/nsThebesRenderingContext.cpp:1148
#2  0xa6bea93d in SetFontFromStyle (aRC=0x852160c, aSC=0xa3f3c99c)
    at mozilla/layout/generic/nsFrame.cpp:439
#3  0xa6c44541 in nsTextFrame::TrimTrailingWhiteSpace (this=0x8613e18, aPresContext=0x8387e70, aRC=@0x852160c, aDeltaWidth=@0xafea44e8,
    aLastCharIsJustifiable=@0xafea44e4)
    at mozilla/layout/generic/nsTextFrame.cpp:6268
#4  0xa6c13577 in nsLineLayout::TrimTrailingWhiteSpaceIn (this=0xafea46d4, psd=0x85cf3c0, aDeltaWidth=0xafea4540)
    at mozilla/layout/generic/nsLineLayout.cpp:2289
#5  0xa6c1368c in nsLineLayout::TrimTrailingWhiteSpace (this=0xafea46d4)
    at mozilla/layout/generic/nsLineLayout.cpp:2350
#6  0xa6bcc163 in nsBlockFrame::PlaceLine (this=0xa3f3c948, aState=@0xafea4a60, aLineLayout=@0xafea46d4, aLine={mCurrent = 0x8613e58},
    aKeepReflowGoing=0xafea4980)
    at mozilla/layout/generic/nsBlockFrame.cpp:3774
#7  0xa6bccd8f in nsBlockFrame::DoReflowInlineFrames (this=0xa3f3c948, aState=@0xafea4a60, aLineLayout=@0xafea46d4, aLine={mCurrent = 0x8613e58},
    aKeepReflowGoing=0xafea4980, aLineReflowStatus=0xafea478c, aAllowPullUp=1)

Comment 6

[Boris Zbarsky [:bzbarsky]]

The problem is all the nested floats.  The patch in bug 320378 seems to fix this bug for me.

Comment 7

[Worcester12345]

For comparison, it didn't crash with Build identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9b2pre) Gecko/2007111202 SeaMonkey/2.0a1pre but it did take quite a while to do the whole page.

Comment 8

[Daniel.S]

With Fx2, it took ages for the testcase to load, but since Firefox 3, the rendering is as quick as any other website.