1807252 - Crash in [@ mozilla::Maybe<T>::emplace<T> | nsGlobalWindowOuter::FullscreenWillChange]

Status: VERIFIED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Kevin Locke]

With Firefox Nightly build 20221223043251 on Debian testing with Sway 1.7 and full-screen-api.ignore-widgets = true, Firefox crashes when the Firefox window is fullscreened and a video is playing in fullscreen mode. Steps to reproduce:

1. Launch Firefox in a fresh profile.
2. Set full-screen-api.ignore-widgets=true in about:config
3. Visit a page with HTML5 video (e.g. https://youtu.be/7ppAQDgRimo)
4. Fullscreen the video and begin playback. (e.g. by pressing the fullscreen video button in the YouTube player)
5. Fullscreen the Firefox window from the window manager. (e.g. press Win+F in Sway)

Pushlog https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=2ace02ead00196c032cc960d1a68a8ce6fd215f3&tochange=903719ec824e3c1a40ba463b5fa06f15005b33b7 suggests that this was regressed by Bug 1801391.

Crash report: https://crash-stats.mozilla.org/report/index/670eddd5-9822-415f-8b35-74a560221223

MOZ_CRASH Reason: MOZ_RELEASE_ASSERT(!isSome())

Top 10 frames of crashing thread:

0  libxul.so  mozilla::Maybe<FullscreenReason>::emplace<FullscreenReason>  mfbt/Maybe.h:844
0  libxul.so  nsGlobalWindowOuter::FullscreenWillChange  dom/base/nsGlobalWindowOuter.cpp:4544
1  libxul.so  mozilla::AppWindow::FullscreenWillChange  xpfe/appshell/AppWindow.cpp:2942
2  libxul.so  mozilla::AppWindow::WidgetListenerDelegate::FullscreenWillChange  xpfe/appshell/AppWindow.cpp:3433
3  libxul.so  nsWindow::OnWindowStateEvent  widget/gtk/nsWindow.cpp:5234
3  libxul.so  window_state_event_cb  widget/gtk/nsWindow.cpp:8231
4  libgtk-3.so.0  _gtk_marshal_BOOLEAN__BOXED  debian/build/deb/gtk/gtkmarshalers.c:84
5  libgobject-2.0.so.0  g_closure_invoke  gobject/gclosure.c:832
6  libgobject-2.0.so.0  signal_emit_unlocked_R  gobject/gsignal.c:3796
7  libgobject-2.0.so.0  g_signal_emit_valist  gobject/gsignal.c:3559

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

:edgar, since you are the author of the regressor, bug 1801391, could you take a look? Also, could you set the severity field?

For more information, please visit auto_nag documentation.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The bug has a crash signature, thus the bug will be considered confirmed.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The bug has a crash signature, thus the bug will be considered confirmed.

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1801391

Comment 5

[Edgar Chen [:edgar]]

To hit the assertion, it requires user to switch full-screen-api.ignore-widgets to true manually in about:config.

Comment 6

[Edgar Chen [:edgar]]

Attachment: Bug 1807252 - Convert full-screen-api.ignore-widgets to static pref; r?smaug

Comment 7

[Edgar Chen [:edgar]]

Attachment: Bug 1807252 - Fix the assertion error when widget fullscreen is prevented; r?smaug

Depends on D165907

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a43025228f8c
Convert full-screen-api.ignore-widgets to static pref; r=smaug
https://hg.mozilla.org/integration/autoland/rev/f58e5f3c02c7
Fix the assertion error when widget fullscreen is prevented; r=smaug

Comment 9

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/a43025228f8c
https://hg.mozilla.org/mozilla-central/rev/f58e5f3c02c7

Comment 10

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

I could not reproduce the crash on a 2022-12-23 Nightly build on Ubuntu 22.
Would you be so kind as to verify the fix on beta/latest Nightly ?

Comment 11

[Kevin Locke]

I can verify that the issue is fixed for me: I'm unable to reproduce the issue on beta 110.0b9 or the latest Nightly (build 20230206213623), while I am still able to reproduce the issue with the old build 20221223212957 (to confirm that the fix was not due to a change on my test system).