User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.66 Safari/537.36 Steps to reproduce: I made any element 100% width x 100% height with top:0, left:0 and fixed positioning. Example file attached as test.html Actual results: element is not properly rendered in Firefox 25 Beta. It seems to be shown under browser top bar (covered by browser top bar). However touch events are handled properly (as if element would be properly rendered) so I need to click about 1cm below rendered button to fire expected event Expected results: element should be displayed in right place (below top bar) like in Firefox <= 24.

Kats, is this is a core issue? If so, can you move it.

The attached test file appears to be using HTML appcache and isn't a full test case. Would you please update the test case with the actual HTML that is causing the problem?

what do you want me to upload? I could add button, but it's not the point - the point is that on my Galaxy S3 even this pink rectangle is not properly rendered in Firefox Beta

test file is available online at: http://bt.staszic.waw.pl/test.html

(In reply to Damian from comment #3) > what do you want me to upload? I could add button, but it's not the point - > the point is that on my Galaxy S3 even this pink rectangle is not properly > rendered in Firefox Beta Sorry I gave wrong file

I can reproduce the behaviour on Fx25 but it's not there on Fx26. Presumably it was fixed by the same thing that fixed bug 903473 and bug 890910. Aaron, it's probably worth trying to track down what fixed this and getting it uplifted to beta as well. Using the regressionwindow-wanted since we don't have a fixwindow-wanted keyword :)

Speculative window as the test-case posted here (http://bt.staszic.waw.pl/test.html) on Nightly (m-c) widely demonstrates differing behaviour on the 2013-09-05 build (screen flickers black on pinch-zoom) from the 2013-09-04 (missing bottom of the window) build http://hg.mozilla.org/mozilla-central/pushloghtml?startdate=2013-09-04&enddate=2013-09-05 Kats, I see bug 910322 in that range which is target milestoned as Firefox 26.

I found the difference you describe to be between the 09-05 build (missing bottom of window) and 09-06 (screen renders black). https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=77ed46bf4c1a&tochange=ab5f29823236 I'll build locally and bisect. I suspect bug 904533.

Yeah, so it was definitely bug 904533 that changed the "missing bottom of window" behaviour to the "screen renders black" behaviour. I suspect one of the (many) followups to that bug fixed the "screen renders black" behaviour. So at this point the options are: 1) leave everything as-is and make this bug wontfix for 25. 2) uplift bug 904533 + dependencies to 25 (and possibly 26, if they landed only on 27). I'm leaning towards (1) because (2) is a high-risk option given how fragile that code is and how far into the beta cycle we currently are.

I'm going to mark this fixed since it is fixed in 26 and 27, and add the dependency on 904533 that fixed it. There are other bugs that were fixed by 904533 and it may get uplifted after all.

As per https://bugzilla.mozilla.org/show_bug.cgi?id=904533#c60 we are going to leave this unfixed in 25 because it's too late/too risky.