1. New profile, start firefox 2. Go to http://www.color.org/version4html.xalter Whilst the page is rendering, large gaps appear in the page and grow and the page is being loaded. Once the page is loaded, resizing the browser window causes the same effect. Changing font size reflows the page and it looks normal. Works: 20070723_1726_firefox-3.0a7pre.en-US.win32.zip Broken: 20070723_1743_firefox-3.0a7pre.en-US.win32.zip http://bonsai.mozilla.org/cvsquery.cgi?module=PhoenixTinderbox&date=explicit&mindate=1185236760&maxdate=1185237779 Due to bug 320378 I think.

I can reproduce with Linux trunk build. Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a7pre) Gecko/2007072422 Minefield/3.0a7pre

Bleh, I should have seen this coming... I'm pretty sure that the dirty bits are getting cleared prematurely. (I haven't figured out what the border-bottom has to do with anything, though... maybe it's suppressing some margin-collapsing code from triggering?) dbaron, any suggestions?

sample : http://allabout.co.jp/ scroll-down to the top/start of contents, mouse-over around there, then wait a while. blank space increases. if you see sites like this, Builds are useless. so this bug should be fixed ASAP, preferably before M7.

This fixes the testcase in this bug; I need to study the implications a bit more, though.

We are probably going to need this for a7. Any sense of ETA?

I recommend backing out the original fix so we can deal with this properly in M8.

"Fixed" by backout of bug 320378.

Wrong M7, beltzner ;)