User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.83 Safari/537.1 Steps to reproduce: Sample page: http://dev.sencha.com/deploy/ext-4.1.0-gpl/examples/portal/portal.html Make the browser small enough so there's a vertical scrollbar. Scroll the page down to the bottom, then back to the top. The bug exists in 15.x, 16.x beta, but is fixed in the 18.x nightly. Is there any chance of a fix being back-ported to make the 16 final? Actual results: Certain elements did not paint correctly. Please see attached screen captures. Expected results: The elements should be painted the same as when initially started.

I can reproduce with HWA on/off in firefox15 --- regressed by Bug 716439 I cannot reproduce with HWA on in firefox16--- fixed in case of HWA on by Bug 757347 But I can reproduce with HWA off in Firefox16. I can not reproduce with HWA on/off anymore in firefox17 and later--- fixed in case of HWA off by Bug 741682 Regression window with HWA on/off(m-c) Good: http://hg.mozilla.org/mozilla-central/rev/2db9df42823d Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120504030509 Broken: http://hg.mozilla.org/mozilla-central/rev/e1a40027dc7e Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120504014349 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=2db9df42823d&tochange=e1a40027dc7e Regression window with HWA on/off(m-i) Good: http://hg.mozilla.org/integration/mozilla-inbound/rev/c608de1b6a53 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120502221102 Broken: http://hg.mozilla.org/integration/mozilla-inbound/rev/77bf50b33a05 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/15.0 Firefox/15.0a1 ID:20120502223302 Pushlog: http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=c608de1b6a53&tochange=77bf50b33a05 Regressed by: Bug 716439 Progression window with HWA on(m-c) Broken: http://hg.mozilla.org/mozilla-central/rev/5c07a681371d Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/16.0 Firefox/16.0 ID:20120626030539 Fixed: http://hg.mozilla.org/mozilla-central/rev/74e503bfa575 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/16.0 Firefox/16.0 ID:20120626015518 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=5c07a681371d&tochange=74e503bfa575 Progression window with HWA on(m-i) Broken: http://hg.mozilla.org/integration/mozilla-inbound/rev/1d8cb944f7a9 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/16.0 Firefox/16.0 ID:20120625193218 Fixed: http://hg.mozilla.org/integration/mozilla-inbound/rev/9a1934aec83c Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/16.0 Firefox/16.0 ID:20120625194619 Pushlog: http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=1d8cb944f7a9&tochange=9a1934aec83c Fixed by: Bug 757347 Progression window with HWA off(m-c) Broken: http://hg.mozilla.org/mozilla-central/rev/82b6c5885345 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120722190243 Fixed: http://hg.mozilla.org/mozilla-central/rev/d78729026fb9 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120723063342 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=82b6c5885345&tochange=d78729026fb9 Progression window with HWA off(m-c) Broken: http://hg.mozilla.org/integration/mozilla-inbound/rev/9302468f64fa Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120722192842 Fixed: http://hg.mozilla.org/integration/mozilla-inbound/rev/a5ee3b2e133a Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120722200242 Pushlog: http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=9302468f64fa&tochange=a5ee3b2e133a Fixed by: Bug 741682

Although this is a recent regression, I doubt we'll be able to take those fixes as is. Including Nick/Matt to see if there may be a low risk fix here. Otherwise, we'll have to untrack, since backing out the regressing bug would likely be risky.

I think backing out 716439 would be difficult and risky at this stage. Pushing 757347 also seems risky since it is a large-ish and complex patch (I've already fixed at least one bug in it). It seems possible that 786817 might fix this, and we plan to push that to at least Aurora and Beta. I have no idea about 741682. I am on sick leave right now, but can check if 786817 fixes this when I return to work (hopefully tomorrow, but maybe Monday).

Hey Nick, I see that bug 786817 has landed on Aurora/Beta - can you confirm now if those landings fix this bug?

Hi, they are landing right now. I will check once I get the builds back.

It works! Tested on Beta and Aurora (latest builds from ftp), and the site works fine on both.