1606821 - Firefox' menu opens if alt key is used in OS' keyboard shortcut

Status: UNCONFIRMED

(Core :: Widget: Gtk, defect, P3)

Description

[msrd0]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:72.0) Gecko/20100101 Firefox/72.0

Steps to reproduce:

I'm using Firefox Developer Edition (72.0b11) with MOZ_ENABLE_WAYLAND=1 (I don't get the issue with XWayland) on a sway window manager. I have setup certain shortcuts to operate on workspaces, including Ctrl+Alt+Left.

Actual results:

When Firefox is the currently focused window, and I press the mentioned shortcut, the menu appears and stays, even if Firefox stays the focused window during the shortcut (so should get both KeyPressed and KeyReleased events).

Expected results:

The menu, if it shows at all, should disappear as soon as I release the Alt key. It shouldn't matter if Firefox stays, looses or gains focus during the action triggered by the shortcut. I see that Firefox uses the Alt key as a trigger to show/hide the menu, but that trigger should not happen if the Alt key is part of some keyboard shortcut.

Comment 1

[Timea Cernea [:tbabos][inactive]]

Tried to reproduce on Windows 10 and Ubuntu 18.06 on the latest Nightly and DevEdition using the same shortcut but didn't manage to. The menu bar won't appear at all in my case.

msrd0, do you also experience this with the latest Firefox Nightly?
Moving this over to a component in the meantime.

Comment 2

[msrd0]

First of all, I accidentialy put Ctrl+Alt+Left whereas my shortcut is Super+Alt+Left, sorry about that. I did some more testing and yes, the behaviour is identical to firefox-nightly 73.0a1.20200106-1 installed from the AUR. One thing I noticed though: I only get the behaviour if I enter Super+Alt+Left (and the menu only triggers after the shortcut finished). With Alt+Super+Left (so the same shortcut, just pressing and holding the alt key while pressing super key) nothing with the menu happens. I am releasing the keys at what I feel is the same time, my computer probably disagrees. If I try to press the keys at the exact same time, I get the menu triggered about every other attempt, so I assume I just can't hit them at the exact same time.

I hope this helps. Let me know if I can provide any other information.

Comment 3

[Kenny Levinsen :kennylevinsen]

Firefox doesn't know it's part of a keyboard shortcut somewhere else. ctrl and alt are both sent to firefox normally, while sway swallows the "left" key events that triggered the binding. In other words, firefox just sees you click alt, which toggles this behavior.

If you don't want alt to toggle the menu bar, set ui.key.menuAccessKeyFocuses to false in about:config. Alternatively, change the key with ui.key.menuAccessKey.