The markup is very similar to bug 1583925, so this can likely use the same approach.

There's some code that appends new rows that needs to be adapted: https://searchfox.org/mozilla-central/rev/581466eef9269afb03d8a0dba2f50215f3a9026c/browser/base/content/browser.js#9187

This is the prompt that shows up when you use alert, prompt or confirm. Offhand, I don't think this really need to use a grid layout.

I also see some unused elements like loginLabel or password1Container and its child elements.

dolske mentioned that if he recalls correctly, tabprompts is just a straight tab-modal port of commonDialog.xul, but it was never used for anything else than web-content prompts.

Backed out for failing test_bug619644.html

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&group_state=expanded&selectedJob=298954159&resultStatus=testfailed%2Cbusted%2Cexception&revision=10bf0d7468e0349634b9ba7291525318e0673402

Failure log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=298954159&repo=autoland&lineNumber=6492
Also: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=298954075&repo=autoland&lineNumber=111307

Backout: https://hg.mozilla.org/integration/autoland/rev/0a7a8447b822f7591d9e867dbf521d1b1ed252db

There is also https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=298954695&repo=autoland&lineNumber=3677

https://hg.mozilla.org/mozilla-central/rev/0aa77ee04caa

This has been backed out in bug 1634075 over regressions in prompt behaviour changes for long unwrappable text, which used to produce a scrollbar and, after the patch in this bug, has the text escaping the prompt box.

It also missed updating the rule in xul.css to use the right namespace, which is probably a more trivial change. It's unclear if the overflow:hidden property in that rule is still useful, so that probably wants figuring out.

(In reply to :Gijs (he/him) from comment #10)

This has been backed out in bug 1634075 over regressions in prompt behaviour changes for long unwrappable text, which used to produce a scrollbar and, after the patch in this bug, has the text escaping the prompt box.

It also missed updating the rule in xul.css to use the right namespace, which is probably a more trivial change. It's unclear if the overflow:hidden property in that rule is still useful, so that probably wants figuring out.

Will this be fixed in time for ESR78?

There's a r+ patch which didn't land and no activity in this bug for 2 weeks.
:ntim, could you have a look please?
For more information, please visit auto_nag documentation.

No, I don’t have time, sorry.

So I rebased the patch and tested it on Linux. I can't reproduce any of the reported regression bugs.
It might be worth testing this again on Windows and OSX too?
Try builds with the changes are here:
https://treeherder.mozilla.org/#/jobs?repo=try&revision=1bcc8db902b1e758e7f88197c96b1d4cd39da556

(In case the alert checkbox still is misaligned by a pixel or two on Windows/OSX then we can easily fix that with some CSS in the right place. I'd be happy to help with that.)

Do we have QA folks who could take these builds for a run?

(In reply to Mats Palmgren (:mats) from comment #15)

So I rebased the patch and tested it on Linux. I can't reproduce any of the reported regression bugs.

Which patch? Your try rev changes text-shadow, which isn't in https://hg.mozilla.org/mozilla-central/rev/0aa77ee04caa , which was the version that got backed out. It looks like you took the last phab revision, which has changes to max-width and overflow and text-shadow (as compared with the original patch). :ntim uploaded that on June 2, a month or two after the backout, but didn't re-request review or attempt to land it, and commented in comment 14 that he didn't have time to finish it. I don't know if there were remaining issues with the patch, but they're unlikely to be the same ones that originally got it backed out.

:ntim, can you clarify what the state of the patch is?

Aside from rebasing, I did attempt to fix the regressions. The text shadow one is fixed, though I don't remember why I didn't land this or request review though.

I can give a quick look again on macOS at finding why again. (though QA would be a lot better than me at this task).

Which patch?

The latest one attached in this bug. (I assumed that was the one that landed and then got backed out.)

@ntim, Let me know if you need help from me with any of this. I'd be happy to fix any remaining issues to get this landed, but I suspect that you'll do it faster since you know your way around this code better than me.

I think it'd be better to have someone closer to QA to work on this. My experience working on this is that fixing one thing can break another. It would take me a lot of time to finish this myself.

Fwiw, I did test bug 1633708 with the try build on OSX and I don't see the issue reported there. Or rather, there is no difference in behavior with/without the patch so I don't think that should block this bug. So as far as I can tell there are no known regressions with this patch so far.

I think we should let QE take the builds in comment 15 for a spin and see if they can find anything.
Gijs, do you know who to n-i?

(In reply to Mats Palmgren (:mats) from comment #20)

Fwiw, I did test bug 1633708 with the try build on OSX and I don't see the issue reported there. Or rather, there is no difference in behavior with/without the patch so I don't think that should block this bug. So as far as I can tell there are no known regressions with this patch so far.

I think we should let QE take the builds in comment 15 for a spin and see if they can find anything.
Gijs, do you know who to n-i?

Tania, is it possible to get some impromptu QE on these try builds around the styling/display of alert, confirm and prompt dialog boxes from webpages (useful testpage at https://javascript.info/alert-prompt-confirm, see bug 1633708 as an example), along the lines of the issues previously filed to do with window sizing, wrapping input text, and general styling on macOS/Windows/Linux , to see if the try builds regress anything compared to the status quo?

Hi, I tested the try build on Windows 10, Mac OsX 10.15 and Ubuntu 18.04 and I did spot a few differences between the Try build from Comment 15 and our latest Nightly build.

For the most parts different prompts and alerts are behaving and look the same on both the Try build from Comment 15 as well as our latest nightly build 84.0a1 (2020-10-29), I have tested a few Pop-ups and Confirmation prompts as well as the prompts from https://javascript.info/alert-prompt-confirm and they are properly displayed.

With Prompts that require Medium to Long text input I noticed a few differences:

• on Mac the pop up is smaller and a scroll bar is displayed that helps the user see the entire text in our latest Nightly build as for the Try build the pop up is bigger and Fixed (no scroll bar is displayed)

• on Windows and Ubuntu in our latest Nightly build 84.0a1 (2020-10-29) the pop is displayed with a scroll bar and the entire text is contained inside the pop up window, as for our Try build the prompt is fixed and TEXT will spill out of the frame

Are there any other examples of Alerts or prompts we should check with the Try build ?

(In reply to Rares Doghi from comment #22)

Hi, I tested the try build on Windows 10, Mac OsX 10.15 and Ubuntu 18.04 and I did spot a few differences between the Try build from Comment 15 and our latest Nightly build.

Thank you!

For the most parts different prompts and alerts are behaving and look the same on both the Try build from Comment 15 as well as our latest nightly build 84.0a1 (2020-10-29), I have tested a few Pop-ups and Confirmation prompts as well as the prompts from https://javascript.info/alert-prompt-confirm and they are properly displayed.

With Prompts that require Medium to Long text input

Sorry, can you clarify what you mean by this? In general, I suspect screenshots would help, for both of the differences you flag up. Please make sure to clearly label the try push vs. latest nightly.

I noticed a few differences:

• on Mac the pop up is smaller and a scroll bar is displayed that helps the user see the entire text in our latest Nightly build as for the Try build the pop up is bigger and Fixed (no scroll bar is displayed)

• on Windows and Ubuntu in our latest Nightly build 84.0a1 (2020-10-29) the pop is displayed with a scroll bar and the entire text is contained inside the pop up window, as for our Try build the prompt is fixed and TEXT will spill out of the frame

Are there any other examples of Alerts or prompts we should check with the Try build ?

I don't think there's anything else, but I'm struggling to follow what these issues are, so I'm hoping the screenshots will help with that.

on Mac the pop up is smaller and a scroll bar is displayed that helps the user see the entire text in our latest Nightly build as for the Try build the pop up is bigger and Fixed (no scroll bar is displayed)

That's very odd since that's not the results I see on OSX nor Linux.

If I enter alert("hi".repeat(1000)) orprompt("hi".repeat(1000)) in the DevTools Console the text is scrollable in both cases. The scrollbar fades away pretty quickly though and I have to hover over the text and try to scroll the text to actually see a scrollbar, but I think that's normal on OSX and I see no difference in that behavior from Nightly. However, I do see a difference in the amount of spacing between the text and scrollbar though. Nightly appears to have some padding there that the Try build lacks (so when the scrollbar is visible it partly overlaps the text, again this is normal for content scrollbars on OSX and isn't a big problem since the scrollbar is semi-transparent and fades away completely when I stop scrolling). Anyway, it's trivial to add a bit of padding-bottom to that element to make it compatible with Nightly if that's desirable.

As for "Medium text" I'm not sure what you mean by that. Could you express that as one of the Console examples I gave above please (but with a different number/text)? Also, I think the window size determines when a scrollbar is triggered so please specify the approximate window size you're using when testing as well.

Ubuntu in our latest Nightly build 84.0a1 (2020-10-29) the pop is displayed with a scroll bar and the entire text is contained inside the pop up window, as for our Try build the prompt is fixed and TEXT will spill out of the frame

Testing the Try build again on Linux, I can't reproduce what you're seeing. I get a scrollbar (static on this platform) when the text is long enough that it is needed. The scrollbar is fully below the text because that's how static scrollbars works.

Rares, could you be more specific what test you're using when the "TEXT will spill out of the frame" so I can try to reproduce that?
Also, at which window size does this happen? Also, can you provide a screenshot of that please?

Thanks for your help!

It seems the issues occur when theres a " " space before or after the pasted words, If you copy something with a space between the words then the text will move to the next row instead of going on the same line. I'll attach a zip file with a few examples from windows.

The Resolution of the Screen is always the Maximum 1080p but I did notice a few differences when the Firefox Window was smaller or when the DevTools were open. Ive attached the screenshots from MAC, Windows and Ubuntu as well, I tried to name the screenshots more clearly but please let me know if I can help in any other way.

Thanks Rares, I see what you mean now. FTR, to reproduce those I used alert("hi ho ".repeat(1000)) in the DevTools Console, with varying numbers. And ditto using prompt(...).

I think I've fixed those problems now. Can you test these new Try builds please?
https://treeherder.mozilla.org/#/jobs?repo=try&revision=5dc55dda908aea5bbf06b4940e2d0481f77403d7

Hi Mats, I have retested the latest Try build and there is only one thing I noticed, on Windows and Ubuntu on the Try build when there is a small window open or the DevTools are enlarged over the page the text from the pop-up window with the "Prevent this page from creating additional dialogs" will spill over the line, where on the Latest Nightly Build the text from the top is the one that its cut.

As for the Mac Try build that text "Prevent this page from creating additional dialogs" that appears the second time you opent the prompt is always spilling even with a full screen page. I will attach some screenshots. Everything else looked great, I couldnt find anything else.

Thanks Rares, I think I have fixed that problem now, can you test again please?
https://treeherder.mozilla.org/jobs?repo=try&revision=1d153436ffd65bda40620f25a2494016ce8dbdf4

Hi Mats, it seems that the only issue I could find was that with a small window that warning text message is going over the grey part of the alert. Ill attach the screenshot for it, everything else looks great.

Thanks for testing. I can reproduce the issue shown on the left above in a local build on Linux.

I don't really see a simple fix for that at the moment, but it also seems like a minor issue. It might even be a better behavior than clipping the message text ("How old are you?") as seen in the right screenshot.

Also, I suspect it's an extremely rare edge case that the viewport would be smaller than the prompt box in practice. So I'm leaning towards leaving it as is.

ntim: WDYT? should we try this on Nightly for a while with the changes I made in https://hg.mozilla.org/try/rev/e92da94475ba76749ed3c69ff32b977fcf843565

Thanks Rares and Mats! I'm ok with trying it in Nightly 84. I've rebased the Phabricator revision, feel free to push on top of it.
In case this needs to be backed out again due to regressions, I'd wait for Nightly 85 for the XUL grid implementation removal.

FWIW, I've tried it again more carefully thanks to Rares' testcases and I did notice two visual changes (though not related to your changes):

• the text is no longer centered vertically for normal text (e.g. alert("Hello world"))
  I saw an align-content: center; on .tabmodalprompt-topContainer helped with that.

• long wrapping text (e.g. alert("hi ho ".repeat(1000)) is now center-aligned horizontally rather than start aligned
  I used text-align: center rather than justify-self: center on .tabmodalprompt-infoContainer. The latter preserves the old behaviour where small text is still centered, but long text isn't.

Regarding the issue Rares found, I wasn't able to reproduce it, even at the smallest window width & viewport height, so might be a very specific issue. Possibly .tabmodalprompt-infoContainer could be made a flex container (e.g. display: flex; flex-direction: column) matching the old behaviour. Might help with this issue but also with the other visual changes by adding align-items: center; justify-content: center; instead of the fixes suggested above.

Backed out changeset 5ed5e8a6bbfb (bug 1583696) for modal prompt related failures.

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&fromchange=bcabae9c2fed5d2a90657f63161319e9fb08024b&searchStr=os%2Cx%2C10.14%2Cwebrender%2Cdebug%2Cmochitests%2Cwithout%2Ce10s%2Ctest-macosx1014-64-qr%2Fdebug-mochitest&tochange=76f13b1a730d342d7851044d546a8c65074cd3f4&selectedTaskRun=MoAnalTYTES-f-CafwvbPQ.0

Backout link: https://hg.mozilla.org/integration/autoland/rev/76f13b1a730d342d7851044d546a8c65074cd3f4

Failures logs:
https://treeherder.mozilla.org/logviewer?job_id=321060099&repo=autoland&lineNumber=5622

[task 2020-11-07T23:41:51.064Z] 23:41:51     INFO - TEST-START | accessible/tests/mochitest/relations/test_ui_modalprompt.html
[task 2020-11-07T23:41:51.122Z] 23:41:51     INFO - GECKO(1595) | [1595, Main Thread] WARNING: Failed to retarget HTML data delivery to the parser thread.: file /builds/worker/checkouts/gecko/parser/html/nsHtml5StreamParser.cpp:1132
[task 2020-11-07T23:41:52.093Z] 23:41:52     INFO - GECKO(1595) | [1595, Main Thread] WARNING: NS_ENSURE_TRUE(rootFrame) failed: file /builds/worker/checkouts/gecko/dom/base/nsGlobalWindowOuter.cpp:4282
[task 2020-11-07T23:41:52.295Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glBlendBarrierKHR" by glcontext
[task 2020-11-07T23:41:52.295Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glBufferStorage" by glcontext
[task 2020-11-07T23:41:52.296Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glBufferStorageEXT" by glcontext
[task 2020-11-07T23:41:52.296Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glColorP3ui" by glcontext
[task 2020-11-07T23:41:52.296Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glColorP3uiv" by glcontext
[task 2020-11-07T23:41:52.296Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glColorP4ui" by glcontext
[task 2020-11-07T23:41:52.296Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glColorP4uiv" by glcontext
[task 2020-11-07T23:41:52.297Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glCopyImageSubData" by glcontext
[task 2020-11-07T23:41:52.297Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glCopyImageSubDataEXT" by glcontext
[task 2020-11-07T23:41:52.297Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glCopyImageSubDataOES" by glcontext
[task 2020-11-07T23:41:52.297Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageCallback" by glcontext
[task 2020-11-07T23:41:52.298Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageCallbackARB" by glcontext
[task 2020-11-07T23:41:52.298Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageCallbackKHR" by glcontext
[task 2020-11-07T23:41:52.298Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageCallbackKHR" by glcontext
[task 2020-11-07T23:41:52.298Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageControl" by glcontext
[task 2020-11-07T23:41:52.299Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageControlARB" by glcontext
[task 2020-11-07T23:41:52.299Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageControlKHR" by glcontext
[task 2020-11-07T23:41:52.299Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageControlKHR" by glcontext
[task 2020-11-07T23:41:52.300Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageInsert" by glcontext
[task 2020-11-07T23:41:52.300Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageInsertARB" by glcontext
[task 2020-11-07T23:41:52.300Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageInsertKHR" by glcontext
[task 2020-11-07T23:41:52.300Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glDebugMessageInsertKHR" by glcontext
[task 2020-11-07T23:41:52.300Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetDebugMessageLog" by glcontext
[task 2020-11-07T23:41:52.310Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetDebugMessageLogARB" by glcontext
[task 2020-11-07T23:41:52.310Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetDebugMessageLogKHR" by glcontext
[task 2020-11-07T23:41:52.310Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetDebugMessageLogKHR" by glcontext
[task 2020-11-07T23:41:52.310Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetObjectLabel" by glcontext
[task 2020-11-07T23:41:52.311Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetObjectLabelKHR" by glcontext
[task 2020-11-07T23:41:52.311Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetObjectLabelKHR" by glcontext
[task 2020-11-07T23:41:52.311Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetObjectPtrLabel" by glcontext
[task 2020-11-07T23:41:52.311Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetObjectPtrLabelKHR" by glcontext
[task 2020-11-07T23:41:52.311Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetObjectPtrLabelKHR" by glcontext
[task 2020-11-07T23:41:52.311Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glGetPointervKHR" by glcontext
[task 2020-11-07T23:41:52.311Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glInvalidateBufferData" by glcontext
[task 2020-11-07T23:41:52.312Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glInvalidateBufferSubData" by glcontext
[task 2020-11-07T23:41:52.312Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glInvalidateFramebuffer" by glcontext
[task 2020-11-07T23:41:52.312Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glInvalidateSubFramebuffer" by glcontext
[task 2020-11-07T23:41:52.312Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glInvalidateTexImage" by glcontext
[task 2020-11-07T23:41:52.312Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glInvalidateTexSubImage" by glcontext
[task 2020-11-07T23:41:52.312Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glMultiTexCoordP1ui" by glcontext
[task 2020-11-07T23:41:52.312Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glMultiTexCoordP1uiv" by glcontext
[task 2020-11-07T23:41:52.312Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glMultiTexCoordP2ui" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glMultiTexCoordP2uiv" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glMultiTexCoordP3ui" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glMultiTexCoordP3uiv" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glMultiTexCoordP4ui" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glMultiTexCoordP4uiv" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glNormalP3ui" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glNormalP3uiv" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glObjectLabel" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glObjectLabelKHR" by glcontext
[task 2020-11-07T23:41:52.313Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glObjectLabelKHR" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glObjectPtrLabel" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glObjectPtrLabelKHR" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glObjectPtrLabelKHR" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glPopDebugGroup" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glPopDebugGroupKHR" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glPopDebugGroupKHR" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glPushDebugGroup" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glPushDebugGroupKHR" by glcontext
[task 2020-11-07T23:41:52.314Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glPushDebugGroupKHR" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glSecondaryColorP3ui" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glSecondaryColorP3uiv" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glShaderStorageBlockBinding" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glTexCoordP1ui" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glTexCoordP1uiv" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glTexCoordP2ui" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glTexCoordP2uiv" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glTexCoordP3ui" by glcontext
[task 2020-11-07T23:41:52.315Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glTexCoordP3uiv" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glTexCoordP4ui" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glTexCoordP4uiv" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glVertexP2ui" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glVertexP2uiv" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glVertexP3ui" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glVertexP3uiv" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glVertexP4ui" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender_bindings::bindings] Could not find symbol "glVertexP4uiv" by glcontext
[task 2020-11-07T23:41:52.316Z] 23:41:52     INFO - GECKO(1595) | [WARN  webrender::device::gl] Missing optimized shader source for gpu_cache_update
[task 2020-11-07T23:41:52.360Z] 23:41:52     INFO - GECKO(1595) | [1595, Main Thread] WARNING: NS_ENSURE_TRUE(presShell) failed: file /builds/worker/checkouts/gecko/dom/base/nsGlobalWindowOuter.cpp:4280
[task 2020-11-07T23:41:52.577Z] 23:41:52     INFO - GECKO(1595) | [1595, Main Thread] WARNING: Failed to retarget HTML data delivery to the parser thread.: file /builds/worker/checkouts/gecko/parser/html/nsHtml5StreamParser.cpp:1132
[task 2020-11-07T23:41:53.726Z] 23:41:53     INFO - GECKO(1595) | [1595, Main Thread] WARNING: Failed to retarget HTML data delivery to the parser thread.: file /builds/worker/checkouts/gecko/parser/html/nsHtml5StreamParser.cpp:1132
[task 2020-11-07T23:47:01.435Z] 23:47:01     INFO - TEST-INFO | started process screencapture
[task 2020-11-07T23:47:01.525Z] 23:47:01     INFO - TEST-INFO | screencapture: exit 0
[task 2020-11-07T23:47:01.526Z] 23:47:01     INFO - Buffered messages logged at 23:41:52
[task 2020-11-07T23:47:01.526Z] 23:47:01     INFO - Invoke the 'show alert' test { scenario #0: expected 'show' event;  }
[task 2020-11-07T23:47:01.526Z] 23:47:01     INFO - Buffered messages logged at 23:41:53
[task 2020-11-07T23:47:01.526Z] 23:47:01     INFO - TEST-PASS | accessible/tests/mochitest/relations/test_ui_modalprompt.html | [ 'tabmodalprompt node', address: [object HTMLUnknownElement] ] is not a target of relation of 'description for' type for '[ 'div@id="infoBody-e05hnfpvuvo" node', address: [object HTMLDivElement] ]'. 
[task 2020-11-07T23:47:01.526Z] 23:47:01     INFO - TEST-PASS | accessible/tests/mochitest/relations/test_ui_modalprompt.html | [ 'div@id="infoBody-e05hnfpvuvo" node', address: [object HTMLDivElement] ] is not a target of relation of 'described by' type for '[ 'tabmodalprompt node', address: [object HTMLUnknownElement] ]'. 
[task 2020-11-07T23:47:01.526Z] 23:47:01     INFO - TEST-PASS | accessible/tests/mochitest/relations/test_ui_modalprompt.html | Test with ID = 'show alert' succeed.  Event 'show' was handled. 
[task 2020-11-07T23:47:01.526Z] 23:47:01     INFO - Invoke the 'cleanup alert' test { scenario #0: expected 'hide' event;  }
[task 2020-11-07T23:47:01.526Z] 23:47:01     INFO - Buffered messages finished
[task 2020-11-07T23:47:01.527Z] 23:47:01     INFO - TEST-UNEXPECTED-FAIL | accessible/tests/mochitest/relations/test_ui_modalprompt.html | Test timed out. 
[task 2020-11-07T23:47:01.527Z] 23:47:01     INFO - SimpleTest.ok@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:417:16
[task 2020-11-07T23:47:01.527Z] 23:47:01     INFO - reportError@chrome://mochikit/content/tests/SimpleTest/TestRunner.js:143:22
[task 2020-11-07T23:47:01.527Z] 23:47:01     INFO - TestRunner._checkForHangs@chrome://mochikit/content/tests/SimpleTest/TestRunner.js:165:18
[task 2020-11-07T23:47:01.527Z] 23:47:01     INFO - openPromptSync@resource://gre/modules/Prompter.jsm:1082:17
[task 2020-11-07T23:47:01.527Z] 23:47:01     INFO - alert@resource://gre/modules/Prompter.jsm:1314:17
[task 2020-11-07T23:47:01.527Z] 23:47:01     INFO - showAlert_invoke/<@chrome://mochitests/content/a11y/accessible/tests/mochitest/relations/test_ui_modalprompt.html:44:46
[task 2020-11-07T23:47:02.541Z] 23:47:02     INFO - GECKO(1595) | MEMORY STAT | vsize 8055MB | residentFast 460MB | heapAllocated 150MB
[task 2020-11-07T23:47:02.569Z] 23:47:02     INFO - TEST-OK | accessible/tests/mochitest/relations/test_ui_modalprompt.html | took 311490ms

https://treeherder.mozilla.org/logviewer?job_id=321060055&repo=autoland&lineNumber=44859

...
[task 2020-11-07T23:51:19.342Z] 23:51:19     INFO - Running tests (modalType=1, usePromptService=true, useBrowsingContext=true, useAsync=false)
[task 2020-11-07T23:51:19.342Z] 23:51:19     INFO - Starting test: Alert
[task 2020-11-07T23:51:19.342Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Services.prompt should have method alertBC. 
[task 2020-11-07T23:51:19.343Z] 23:51:19     INFO - Calling Services.prompt.alertBC([object CanonicalBrowsingContext],1,TestTitle,This is the alert text.)
[task 2020-11-07T23:51:19.343Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Container should have y > 0 - true == true 
[task 2020-11-07T23:51:19.343Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check tabmodalprompt is visible - {} == {} 
[task 2020-11-07T23:51:19.343Z] 23:51:19     INFO - Click to the left of the dialog over the content area
[task 2020-11-07T23:51:19.343Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check clicks on the content area don't go to the browser - {} != [object XULFrameElement] 
[task 2020-11-07T23:51:19.343Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check clicks on the content area go to the prompt dialog background - {} == {} 
[task 2020-11-07T23:51:19.344Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Dialog must not overlap with toolbox. - true == true 
[task 2020-11-07T23:51:19.344Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check browser has @tabmodalPromptShowing - true == true 
[task 2020-11-07T23:51:19.345Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | If method is async it should return a promise. 
[task 2020-11-07T23:51:19.345Z] 23:51:19     INFO - checkPromptState: Expected: This is the alert text.
[task 2020-11-07T23:51:19.345Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking expected message 
[task 2020-11-07T23:51:19.345Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking title visibility 
[task 2020-11-07T23:51:19.345Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking textbox visibility 
[task 2020-11-07T23:51:19.346Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking passbox visibility 
[task 2020-11-07T23:51:19.346Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox visibility 
[task 2020-11-07T23:51:19.346Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox label 
[task 2020-11-07T23:51:19.346Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox checked 
[task 2020-11-07T23:51:19.346Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking textbox value 
[task 2020-11-07T23:51:19.346Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking passbox value 
[task 2020-11-07T23:51:19.346Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button0 default 
[task 2020-11-07T23:51:19.350Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button1 default 
[task 2020-11-07T23:51:19.351Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button2 default 
[task 2020-11-07T23:51:19.351Z] 23:51:19     INFO - Buffered messages finished
[task 2020-11-07T23:51:19.351Z] 23:51:19     INFO - TEST-UNEXPECTED-FAIL | toolkit/components/prompts/test/test_modal_prompts.html | buttons don't focus on OS X, but infoBody does instead - got null, expected "infoBody"
[task 2020-11-07T23:51:19.351Z] 23:51:19     INFO - SimpleTest.is@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:500:14
[task 2020-11-07T23:51:19.351Z] 23:51:19     INFO - checkPromptState@chrome://mochitests/content/chrome/toolkit/components/prompts/test/prompt_common.js:294:7
[task 2020-11-07T23:51:19.351Z] 23:51:19     INFO - handlePrompt@chrome://mochitests/content/chrome/toolkit/components/prompts/test/prompt_common.js:191:19
[task 2020-11-07T23:51:19.351Z] 23:51:19     INFO - Starting test: AlertCheck (null checkbox label, so it's hidden)
[task 2020-11-07T23:51:19.351Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Services.prompt should have method alertCheckBC. 
[task 2020-11-07T23:51:19.352Z] 23:51:19     INFO - Calling Services.prompt.alertCheckBC([object CanonicalBrowsingContext],1,TestTitle,This is the alertCheck text.,,[object Object])
[task 2020-11-07T23:51:19.352Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Container should have y > 0 - true == true 
[task 2020-11-07T23:51:19.352Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check tabmodalprompt is visible - {} == {} 
[task 2020-11-07T23:51:19.352Z] 23:51:19     INFO - Click to the left of the dialog over the content area
[task 2020-11-07T23:51:19.352Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check clicks on the content area don't go to the browser - {} != [object XULFrameElement] 
[task 2020-11-07T23:51:19.352Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check clicks on the content area go to the prompt dialog background - {} == {} 
[task 2020-11-07T23:51:19.352Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Dialog must not overlap with toolbox. - true == true 
[task 2020-11-07T23:51:19.353Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check browser has @tabmodalPromptShowing - true == true 
[task 2020-11-07T23:51:19.353Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | If method is async it should return a promise. 
[task 2020-11-07T23:51:19.353Z] 23:51:19     INFO - checkPromptState: Expected: This is the alertCheck text.
[task 2020-11-07T23:51:19.353Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking expected message 
[task 2020-11-07T23:51:19.353Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking title visibility 
[task 2020-11-07T23:51:19.353Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking textbox visibility 
[task 2020-11-07T23:51:19.354Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking passbox visibility 
[task 2020-11-07T23:51:19.354Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox visibility 
[task 2020-11-07T23:51:19.354Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox label 
[task 2020-11-07T23:51:19.354Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox checked 
[task 2020-11-07T23:51:19.354Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking textbox value 
[task 2020-11-07T23:51:19.354Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking passbox value 
[task 2020-11-07T23:51:19.355Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button0 default 
[task 2020-11-07T23:51:19.355Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button1 default 
[task 2020-11-07T23:51:19.358Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button2 default 
[task 2020-11-07T23:51:19.358Z] 23:51:19     INFO - Not taking screenshot here: see the one that was previously logged
[task 2020-11-07T23:51:19.358Z] 23:51:19     INFO - TEST-UNEXPECTED-FAIL | toolkit/components/prompts/test/test_modal_prompts.html | buttons don't focus on OS X, but infoBody does instead - got null, expected "infoBody"
[task 2020-11-07T23:51:19.358Z] 23:51:19     INFO - SimpleTest.is@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:500:14
[task 2020-11-07T23:51:19.358Z] 23:51:19     INFO - checkPromptState@chrome://mochitests/content/chrome/toolkit/components/prompts/test/prompt_common.js:294:7
[task 2020-11-07T23:51:19.358Z] 23:51:19     INFO - handlePrompt@chrome://mochitests/content/chrome/toolkit/components/prompts/test/prompt_common.js:191:19
[task 2020-11-07T23:51:19.359Z] 23:51:19     INFO - Starting test: AlertCheck
[task 2020-11-07T23:51:19.359Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Services.prompt should have method alertCheckBC. 
[task 2020-11-07T23:51:19.359Z] 23:51:19     INFO - Calling Services.prompt.alertCheckBC([object CanonicalBrowsingContext],1,TestTitle,This is the alertCheck text.,Check me out!,[object Object])
[task 2020-11-07T23:51:19.359Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Container should have y > 0 - true == true 
[task 2020-11-07T23:51:19.359Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check tabmodalprompt is visible - {} == {} 
[task 2020-11-07T23:51:19.360Z] 23:51:19     INFO - Click to the left of the dialog over the content area
[task 2020-11-07T23:51:19.361Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check clicks on the content area don't go to the browser - {} != [object XULFrameElement] 
[task 2020-11-07T23:51:19.361Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check clicks on the content area go to the prompt dialog background - {} == {} 
[task 2020-11-07T23:51:19.361Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Dialog must not overlap with toolbox. - true == true 
[task 2020-11-07T23:51:19.361Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Check browser has @tabmodalPromptShowing - true == true 
[task 2020-11-07T23:51:19.361Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | If method is async it should return a promise. 
[task 2020-11-07T23:51:19.361Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checkbox was checked 
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - checkPromptState: Expected: This is the alertCheck text.
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking expected message 
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking title visibility 
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking textbox visibility 
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking passbox visibility 
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox visibility 
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox label 
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking checkbox checked 
[task 2020-11-07T23:51:19.366Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking textbox value 
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | Checking passbox value 
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button0 default 
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button1 default 
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - TEST-PASS | toolkit/components/prompts/test/test_modal_prompts.html | checking button2 default 
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - Not taking screenshot here: see the one that was previously logged
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - TEST-UNEXPECTED-FAIL | toolkit/components/prompts/test/test_modal_prompts.html | buttons don't focus on OS X, but infoBody does instead - got null, expected "infoBody"
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - SimpleTest.is@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:500:14
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - checkPromptState@chrome://mochitests/content/chrome/toolkit/components/prompts/test/prompt_common.js:294:7
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - handlePrompt@chrome://mochitests/content/chrome/toolkit/components/prompts/test/prompt_common.js:191:19
[task 2020-11-07T23:51:19.367Z] 23:51:19     INFO - Starting test: Confirm (ok)
...

The following also seems to start perma failing with the backed out changes:
https://treeherder.mozilla.org/logviewer?job_id=321063309&repo=autoland&lineNumber=17643

I suspect it might be this change that caused these failures:
https://phabricator.services.mozilla.com/D61442?vs=363896&id=363911#toc
Jamie said "I think we should probably remove this tabindex. That will probably break a test, but I'd say the test is probably wrong. I don't see any good reason for this to be focusable."

If reverting that change makes all tests pass, then we should re-land it without it. Then we can work on that bit in a follow-up bug.

OK, I see you're already working on that :-)

Doh, this patch actually got backed out for the same issue in comment 6/7.

I've dug into Matrix messages from April 23, and I found some context starting from here:

https://matrix.to/#/!jmuErVonajdNMbgdeY:mozilla.org/$kjBXXnDWnT4h_5UXIEdfRDMpr3IVpmb0pA0iEVnEgPc?via=mozilla.org&via=matrix.org&via=igalia.com

It restores the old focus behaviour (according to the matrix messages I wrote at the time), so I'm not too worried for now. Filed bug 1675992 to deal with this.

https://hg.mozilla.org/mozilla-central/rev/d366215bf9af

Thank you Mats, Tim and Rares for all your work towards resolving this!

This issue is Verified as fixed in our latest Nightly build 84.0a1 (2020-11-08) on Windows 10, Ubuntu 18.04 and Mac OsX 10.15.