1969373 - Wheel-scrolling is missing the first event

Status: UNCONFIRMED

(Core :: Widget: Gtk, defect)

Description

[tgn-ff]

Steps to reproduce:

I'm on KDE/X11.

1. Open a long page, where the scrollbar is visible, like about:support.
2. Click outside of the window.
3. Hover over the window with the pointer and scroll using the wheel, OR click on the window first then try to use the wheel to scroll.

Actual results:

The first scrolling event is missed, regardless of whether the window is focused first or not.

Expected results:

This was introduced in Bug 1967375. Setting MOZ_USE_XINPUT2=0 works around the issue.

https://hg-edge.mozilla.org/integration/autoland/pushloghtml?fromchange=55eed5cc7885d0fe358984626e29a09c332e9742&tochange=15ff5b9a03927d49370827c12a698866a8e141cf

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

:saschanaz, since you are the author of the regressor, bug 1967375, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Kagami Rosylight [:saschanaz] (they/them)]

Can you provide more details:

• KDE version?
• distribution and its version?
• gtk3 version?

Comment 3

[tgn-ff]

KDE Plasma: 6.3.5
KDE Frameworks: 6.14.0
Qt: 6.9.0
GTK3: 3.24.49
distribution: Arch Linux

Comment 4

[Kagami Rosylight [:saschanaz] (they/them)]

Hmm, I can reproduce it, and very interestingly Chrome has the same issue.

KDE Plasma: 6.2.5
KDE Frameworks: 6.9.0
Qt: 6.8.1
GTK3: 3.24.43-4
distribution: Steam OS

So I guess this is still a KDE issue?

Comment 5

[Kagami Rosylight [:saschanaz] (they/them)]

Actually with MOZ_USE_XINPUT2=1 and gtk 3.24.41, Ubuntu 24.04.2 LTS with Gnome 46.0 shows the same issue. Also on Chrome. Is this just the behavior of xinput2? 🤔

Comment 6

[Martin Stránský [:stransky] (ni? me)]

Looks like so.