646438 - Firefox 4 needs over one minute to display a webpage with MathJax content in conjunction with -moz-column-count and hangs

Status: RESOLVED DUPLICATE of bug 646437

(Firefox :: General, defect)

Description

[René Schwarz]

User-Agent:       Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0
Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0

Firefox 4 needs over one minute to render that page with MathJax (<http://www.mathjax.org/>) content in conjunction with -moz-column-count CSS:

<http://tools.rene-schwarz.com/demos/ff4-hangs-mathjax-columns/>

During rendering Firefox 4 hangs and is not usable for over one minute. In Opera 11.01 page rendering tooks 2 or 3 seconds (depending on connection speed) and Opera is normally usable for this period.

I suppose that this is a problem with the permanent re-ordering of page elements due to -moz-column-count. So it is not surprising that the page rendering in Opera is fast -- Opera doesn't support the CSS column-count property yet. But Chrome, supporting the CSS column-count property, doesn't hang during page parsing and is really fast.

BTW: Chrome 10 is crashing on my system trying to parse that page.

Reproducible: Always

Actual Results:  
Firefox 4 hangs over one minute, permanently reordering column elements

Expected Results:  
Firefox 4 is usable the time during page request and rendering, rendering should take no longer than a few seconds.

Comment 1

[René Schwarz]

Sorry for double posting -- the Bugzilla webserver was not reachable (error 500) and so I submitted the bug report twice.