1728344 - (Windows 10) Abusing confirmation close dialog (Alt+F4) hangs the browser

Status: NEW

(Firefox :: Tabbed Browser, defect)

Description

[Adrian Florinescu [:aflorinescu]]

[Description:]

While tinkering with bug 1720254, I accidentaly realized that abusing the alt+F4 will shortly enter the browser into an unresponsive state.

#####[Environment:]
Windows 10
Ubuntu 20.04.3 - doesn't reproduce
Mac 11.0.4 - doesn't reproduce (@ cmd+Q)

[Steps:]

1. New profile, about:preferences#general, enable session restore and warn on close.
2. Ctrl+T open several new tabs.
3. Forget your fingers on Alt+F4.

[Actual Result:]

The browser hangs, needs to be terminated from task manager.

[Expected Result:]

The browser doesn't hang :)

[Regression Range:]

2021-08-31T18:21:49.381000: DEBUG : Found commit message:
Bug 1685313 - fix tests to pass with either the new or old window modal dialogs, r=jaws

Differential Revision: https://phabricator.services.mozilla.com/D104703

Comment 1

[Marco Castelluccio [:marco]]

Gijs, could you take a look?

Comment 2

[:Gijs (he/him)]

I don't think this is S2; I think the STR here are an edgecase. It's basically the Windows version of bug 1705365, which has a patch up that hasn't had review requested, because there are some UX implications. I don't think there is another fix that doesn't have those implications, so I guess I'll follow up there.