User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0 Build ID: 20180205100240 Steps to reproduce: Turned on High Contrast Black Opened a webpage that takes a long time to load Opened another tab Left it open for a few hours Switched back to the original tab I thought this was part of #1419152 but it isn't. Reproduced OSes: Windows x86 (latest release), Linux Debian x64 (trunk) Actual results: screen turned almost solid white for several seconds. I'm pretty sure there's a spinner in the center. Please note this has happened on enough websites to rule out js code on the website causing it Expected results: screen should be black until re-render finished

Is this another regression from bug 1379587? A duplicate of one of those other bugs (see "See Also")?

(In reply to Dão Gottwald [::dao] from comment #1) > Is this another regression from bug 1379587? I don't think so, it sounds to me like it's the tab switch spinner that would need to be adapted to high contrast/dark themes. Mike, does this seem right?

(In reply to Florian Quèze [:florian] from comment #2) > I don't think so, it sounds to me like it's the tab switch spinner that > would need to be adapted to high contrast/dark themes. Mike, does this seem > right? Yes, this sounds right. I suspect the colour that Joshua was seeing was this one: https://searchfox.org/mozilla-central/rev/78dbe34925f04975f16cb9a5d4938be714d41897/browser/base/content/tabbrowser.css#96

Comment on attachment 8972828 [details] Bug 1440865 - Stop overriding tabbrowser-tabpanels' background for [pendingpaint]. https://reviewboard.mozilla.org/r/241396/#review247318 This is a great idea, and we should totally do this - except that the spinner seems to have the background colour hard-coded behind it, so things look a bit odd, for example, in private browsing windows: https://imgur.com/a/FRVJiee I wonder if we should swap out the spinner with an APNG with a transparent background or something.

(In reply to Mike Conley (:mconley) (:⚙️) (Totally backlogged on reviews and needinfos) from comment #7) > Comment on attachment 8972828 [details] > Bug 1440865 - Stop adjusting tabbrowser-tabpanels' background for > [pendingpaint] and use -moz-default-background-color for high contrast > themes. > > https://reviewboard.mozilla.org/r/241396/#review247318 > > This is a great idea, and we should totally do this - except that the > spinner seems to have the background colour hard-coded behind it, so things > look a bit odd, for example, in private browsing windows: > > https://imgur.com/a/FRVJiee > > I wonder if we should swap out the spinner with an APNG with a transparent > background or something. Stephen, could you provide us with such an image? The file in question is pendingpaint.png.

This should work on different colored backgrounds.

Comment on attachment 8972828 [details] Bug 1440865 - Stop overriding tabbrowser-tabpanels' background for [pendingpaint]. https://reviewboard.mozilla.org/r/241396/#review250086 Yeah, this looks great! Thanks!

Pushed by dgottwald@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/4e1b874e708b Stop overriding tabbrowser-tabpanels' background for [pendingpaint]. r=mconley

Comment on attachment 8972828 [details] Bug 1440865 - Stop overriding tabbrowser-tabpanels' background for [pendingpaint]. Approval Request Comment [Feature/Bug causing the regression]: not a recent regression [User impact if declined]: jarring experience when switching tabs and using a dark high contrast theme [Is this code covered by automated tests?]: no [Has the fix been verified in Nightly?]: not yet [Needs manual test from QE? If yes, steps to reproduce]: see comment 0 [List of other uplifts needed for the feature/fix]: / [Is the change risky?]: no [Why is the change risky/not risky?]: simple CSS fix [String changes made/needed]: /

Comment on attachment 8972828 [details] Bug 1440865 - Stop overriding tabbrowser-tabpanels' background for [pendingpaint]. Simple fix for users with dark high contrast themes. Approved for 61.0b6.

I've reproduced the comment 0 issue on 61.0a1 20180421220102 and verified it as fixed on Windows8.1 x64 and Windows 10x64 for: 61.0b5 2018-05-14 62.0a1 2018-05-16 Linux related, I'm not sure how this issue applies, since as default the high contrast background is white. (Ubuntu 16.04 & Debian 9.3). I wonder if I should use a custom black theme to test this fix? Joshua, do you use a custom black theme on Debian?

That would be correct more or less correct. I use a stock dark theme on Debian. joshua@novaϟ env [snip] LANG=en_US.UTF-8 MOZ_ALLOW_GTK_DARK_THEME=true QT_LINUX_ACCESSIBILITY_ALWAYS_ON=1 GTK_THEME=Adwaita:dark _=/usr/bin/env joshua@novaϟ

Joshua, would you be willing to help verifying this issue and thus confirming that this issue is fixed for high contrast Debian?

Hey; I just installed the latest nightly to test it but it will be some time before I can be certain it's fixed. I never got a reliable reproduction so making sure it is dead is hard.

And I think I clicked the wrong button.

I'll mark this issue as verified based on comment 17, since only on Debian we still have to fully confirm this issue as fixed and I reckon if the case be we could open a new issue to track linux.

I have now actually confirmed the fix on Firefox Nightly. (I managed to get a tab to hang due to a spotty DNS server making confirmation obvious.)

I reckon no action is required now for this issue. Thanks a lot Joshua for involvement and help.