Bug 514107

Summary:	Qt-based context menus open in the wrong place immediately after toggling fullscreen, before moving pointer at all
Product:	[Plasma] kwin	Reporter:	Philipp Maierhöfer <maiphi.public>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	CONFIRMED ---
Severity:	minor	CC:	kdedev, nate
Priority:	NOR
Version First Reported In:	6.5.4
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Philipp Maierhöfer 2026-01-03 12:06:23 UTC

SUMMARY
In the plasma-wayland session, when toggling an application to fullscreen or back and then opening the context menu without moving the mouse, the context menu opens in the wrong place.

Not all applications are affected, and it's not strictly related to Qt:
* affected: probably all KDE applications (tested some), libreoffice, firefox, haruna, inkscape,
* not affected: vlc-qt, smplayer.

STEPS TO REPRODUCE
1. Open an application that has a fullscreen mode and toggle to fullscreen.
2. Do not move the mouse.
3. Right-click and see where the context menu opens.

OBSERVED RESULT
The context menu opens, but not in the place where the mouse pointer is. When the window is at (x,y) and the mouse pointer is at (x+dx, y+dy), the context menu opens at (dx,dy).

EXPECTED RESULT
The context menu should open at the position of the mouse pointer.

SOFTWARE/OS VERSIONS
Linux: Tumbleweed 20260101, kernel 6.18.2-1
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1

ADDITIONAL INFORMATION
* It also happens when turning fullscreen off.
* Only happens in the wayland session.
* Apparently the pointer coordinates are not updated correctly. But the mouse pointer itself is always correctly positioned, e.g. it does not jump to the "wrong" location.

Comment 1 TraceyC 2026-01-05 20:11:28 UTC

I'm not able to reproduce this in Plasma built from git-master or Plasma 6.5.4 on Solus.

Note about Haruna - the context menu opens near but not at the same place relative to the mouse cursor if the cursor is near the edge of the window. Firefox's context menu doesn't behave the same way. The menus pop up in the same place before during and after fullscreen mode.

Tested with: Firefox, LibreOffice Writer, Haruna

I'll leave this open so others can try to reproduce

Comment 2 Nate Graham 2026-01-06 22:52:04 UTC

Can reproduce! How strange.

Comment 3 Vlad Zahorodnii 2026-01-08 14:15:10 UTC

Qt probably has an outdated pointer position. kwin may need to send a wl_pointer warp event to Qt when the window is moved and resized.