Bug 7559 - AltGr+<key> slightly broken in Firefox on Windows
Summary: AltGr+<key> slightly broken in Firefox on Windows
Alias: None
Product: ThinLinc
Classification: Unclassified
Component: Web Access (show other bugs)
Version: trunk
Hardware: PC Unknown
: P2 Normal
Target Milestone: 4.14.0
Assignee: Linn
Keywords: prosaic, samuel_tester
Depends on: 7792
Blocks: keyboard
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Reported: 2020-09-28 11:03 CEST by Pierre Ossman
Modified: 2021-11-22 14:38 CET (History)
2 users (show)

See Also:
Acceptance Criteria:


Description Pierre Ossman cendio 2020-09-28 11:03:42 CEST
Right now using AltGr plus another key isn't working exactly as it should when using Firefox on Windows. The AltGr key is released when the second key is pressed, even though AltGr is still active.

I.e. when doing this sequence:

1. Press AltGr
2. Press o
3. Release o
4. Release AltGr

The server instead sees:

1. Press AltGr
2. Press o
3. Release AltGr
4. Release o

This rarely breaks anything, but could cause problems in some corner cases so we should fix it.

Upstream report:

Comment 1 Samuel Mannehed cendio 2021-04-05 21:59:34 CEST
This is fixed in upstream noVNC.
Comment 4 Samuel Mannehed cendio 2021-11-17 13:32:15 CET
Should be fixed by the vendordrop in 7792, needs to be tested.
Comment 6 Linn cendio 2021-11-18 16:40:44 CET
Tested with Webaccess in Firefox 94 on Windows 10 and server build 2350 on RHEL 8. 

The server now sees the correct sequence when pressing e.g. AltGr + o:

1. Press AltGr
2. Press o
3. Release o
4. Release AltGr

Also works correctly for when replacing AltGr with Ctrl and/or Alt key.
Comment 7 Samuel Mannehed cendio 2021-11-22 14:38:30 CET
I could reproduce the issue using Firefox 91 on Windows 10 against a 4.13.0 server on Fedora 34. The problem didn't appear exactly as described in comment #0, but similar enough. I could see in the output from 'xev' running in the session that I got:

 KeyPress AltGr
 KeyRelease AltGr
 KeyPress o
 KeyRelease o

While I actually pressed the keys like this:

 KeyPress AltGr
 KeyPress o
 KeyRelease o
 KeyRelease AltGr

I can verify that the problem is now fixed with a nightly server (build 2355). I get the expected sequence of key events shown by 'xev' in the session.

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