Bug 493025 - Unable to associate CTRL+ALT+BACKSPACE sequence as a shortcut; BACKSPACE detected as "Unidentified"
Summary: Unable to associate CTRL+ALT+BACKSPACE sequence as a shortcut; BACKSPACE dete...
Status: REPORTED
Alias: None
Product: plasmashell
Classification: Plasma
Component: general (show other bugs)
Version: 6.1.5
Platform: Debian unstable Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-09-12 17:43 UTC by antonio
Modified: 2024-09-20 18:48 UTC (History)
4 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
sequence detected from www.mechanical-keyboard.org/ (130.46 KB, image/png)
2024-09-19 13:20 UTC, antonio
Details

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Description antonio 2024-09-12 17:43:53 UTC
I can't bind the CTRL+ALT+BACKSPACE shortcut to Plasma "logout without confirmation", the backspace key does not seem to be detected when associated with ALT+CTRL (while other combinations, for example: CTRL+META+BACKSPACE, are correctly detected).

Thanks,
Antonio

SOFTWARE/OS VERSIONS
Operating System: Debian GNU/Linux 12
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.5.0
Qt Version: 6.6.2
Kernel Version: 6.10.9-1-liquorix-amd64 (64-bit)
Graphics Platform: Wayland
Processors: 24 × 12th Gen Intel® Core™ i9-12900T
Memory: 31.1 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 770
Manufacturer: ASUS
Comment 1 antonio 2024-09-13 11:50:32 UTC
> Same problem on Gecko:

Operating System: openSUSE Tumbleweed 20240911
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.5.0
Qt Version: 6.7.2


> OK on Fedora 40:

Operating System: Fedora Linux 40
KDE Plasma Version: 6.1.4
KDE Frameworks Version: 6.5.0
Qt Version: 6.7.2
Comment 2 Noah Davis 2024-09-19 11:32:57 UTC
I cannot reproduce this. It could be that your keyboard does not support this combination of keys. Try this website: https://www.mechanical-keyboard.org/key-rollover-test/
Comment 3 antonio 2024-09-19 13:19:39 UTC
(In reply to Noah Davis from comment #2)
> I cannot reproduce this. It could be that your keyboard does not support
> this combination of keys. Try this website:
> https://www.mechanical-keyboard.org/key-rollover-test/

The test was helpful because the "backspace" key is detected as "unidentified" (ctrl,alt,unidentified), even though it still detects the sequence of three pressed keys.

However it can't be a keyboard problem, because it was working end a month or two ago (I couldn't tell you the exact version of plasma/framework from which it stopped working).

It can't even be a distribution-specific issue since a couple of them have the problem. I think one of the plasma updates created the problem.
Comment 4 antonio 2024-09-19 13:20:31 UTC
Created attachment 173873 [details]
sequence detected from www.mechanical-keyboard.org/
Comment 5 Nate Graham 2024-09-19 18:51:02 UTC
Can you clarify where exactly you're trying to set this shortcut? Is it on System Settings' Shortcuts page?
Comment 6 antonio 2024-09-20 07:12:21 UTC
(In reply to Nate Graham from comment #5)
> Can you clarify where exactly you're trying to set this shortcut? Is it on
> System Settings' Shortcuts page?

Yes, I open "systemsettings" and select:
  - Keyboard
    - Shortcuts
      - Session Management
        - "exit without confirm"
        - button "add custom shortcut"
        - press "ALT+CTRL+BACKSPACE"

but only ALT+CTRL is shown on the screen, BACKSPACE is not ignored (as if I had not pressed it).

However, if I try other combinations, for example: CTRL+SHIFT+BACKSPACE, META+SHIFT+BACKSPACE, ALT+META+BACKSPACE, ALT+SHIFT+BACKSPACE, they are recognized correctly and accepted.

Before the problem occurred I had already set this shortcut with the indicated sequence and it worked fine; for some time I noticed that this shortcut did not work anymore, so I went back to the shortcuts page and nothing had changed, the screen always showed CTRL+ALT+BACKSPACE, even if it did not work. So I tried to reset it again, but I noticed it no longer accepted this combination.
Comment 7 Nate Graham 2024-09-20 18:00:02 UTC
I can successfully set that combination on my system FWIW.
Comment 8 antonio 2024-09-20 18:48:08 UTC
For a simple test you can also try with OpenSuse live (from: https://download.opensuse.org/download/distribution/openSUSE-current/live/openSUSE-Leap-15.6-KDE-Live-x86_64-Build13.327-Media.iso):

- start iso
- system settings
- switch to sidebar view button
- shortcuts
- ksmserver
- log out without confirmation
- add custom shortcuts button
- press: ALT+CTRL+BACKSPACE

same problem, the third key pressed, "backspace", is not detected

and there is a different version of kde/framework:

Operating System: openSUSE Leap 15.6
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.12
Kernel Version: 6.4.0-150600.23.17-default (64-bit)

maybe it could be an indirect problem generated by a library