Bug 502583 - [Wayland] Scroll input is doubled in the same direction
Summary: [Wayland] Scroll input is doubled in the same direction
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: input (show other bugs)
Version: 6.3.4
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-04-08 22:29 UTC by madness742
Modified: 2025-04-12 00:37 UTC (History)
2 users (show)

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


Attachments
Showcase of the bug. (2.22 MB, video/webm)
2025-04-08 22:29 UTC, madness742
Details

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Description madness742 2025-04-08 22:29:00 UTC
Created attachment 180104 [details]
Showcase of the bug.

SUMMARY
I initially reported this on virt-viewer GitLab, but I'm unable to reproduce it on Gnome. (https://gitlab.com/virt-viewer/virt-viewer/-/issues/161)

When scrolling in the virt-viewer, every second scroll input in the same direction is doubled.

STEPS TO REPRODUCE
1. Create a Linux VM in virt-manager.
2. Open a web browser.
3. Scroll in the same direction.

OBSERVED RESULT
Every other scroll in the same direction, is doubled.

EXPECTED RESULT
It should only send one scroll input.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 41
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0 
Qt Version: 6.8.2

ADDITIONAL INFORMATION
This bug also affects connections to the VM using different clients, such as Remmina. Oddly enough, Moonlight doesn't appear to be affected.

Workaround for this bug:
- Launch virt-manager/virt-viewer with GDK_BACKEND=x11.
- Use 'Redirect USB Device' for the mouse in virt-viewer, but this makes the cursor invisible.
Comment 1 Zamundaaa 2025-04-09 13:23:11 UTC
Do you have a non-default scroll speed configured in system settings?
Comment 2 madness742 2025-04-09 16:39:22 UTC
(In reply to Zamundaaa from comment #1)
> Do you have a non-default scroll speed configured in system settings?

I'm using the default scroll speed settings, this bug also happens on a clean install of Fedora 41.

I've also tried several input devices in case it was the hardware to blame:
- Ploopy Adept (QMK, wired)
- Kesington Slimblade Pro (USB, wired and dongle)
- Pulsar Xlite V2 (Dongle)
- Logitech MX Master 3s (Bluetooth and dongle)
Comment 3 madness742 2025-04-12 00:37:29 UTC
I've changed the status back to "REPORTED", please let me know if you need more information.