1574057 - preventDefault doesn't work for Alt key

Status: RESOLVED DUPLICATE of bug 1292053

(Core :: DOM: Events, defect, P2)

Description

[Xidorn Quan [:xidorn] UTC+11]

Attachment: testcase

Steps to reproduce:

1. open the testcase on Windows
2. press alt key

Actual result:
the menu bar shows up

Expect result:
the menu bar should not show up

The testcase basically just invoke preventDefault on every keyup event. This works fine on Chrome (if you press alt without preventDefault, you can see that the three dot menu on the top right gets activated on Chrome).

This is important for web apps which want to utilize alt key as a switch of certain functionality.

Comment 1

[Hsin-Yi Tsai (she/her) [:hsinyi]]

Is this a recent regression?

Comment 2

[Xidorn Quan [:xidorn] UTC+11]

I believe this is a regression from e10s. I tested a version of Firefox 48 where e10s is enabled by default but it is still possible to open non-e10s window, this issue exists on e10s window but not on non-e10s one.

Comment 3

[Pierre Ossman]

This is very annoying in noVNC which gives you remote access to a different machine. A fix would be appreciated.