Bug 448961

Summary: Window jumps to differnet location when dragging it by the menu bar
Product: [Plasma] kwin Reporter: Philipp Maierhöfer <maiphi.public>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED WORKSFORME    
Severity: normal CC: nate
Priority: NOR    
Version First Reported In: 5.23.90   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Philipp Maierhöfer 2022-01-22 16:43:09 UTC 
SUMMARY
For some non-KDE applications that can be dragged from the menu bar (or other window content), the window can suddenly jump to a different location when dragged.

I observed this behaviour with VLC, SMPlayer and Libre Office on KDE Neon user and testing 20220118 and openSUSE Krypron from today (and a similar issue on Tumbleweed, see below).

STEPS TO REPRODUCE
1. Play a video with VLC or SMPlayer (it is important to play a video, the bug may not occur otherwise).
2. Left-click and hold the menu bar (in case of SMPlayer the video region can be used as well).
3. Drag the window.

OBSERVED RESULT
The window suddenly jumps to a different location so that its top left corner is now under the pointer. It may also happen that the leftmost menu opens either together with the jump, or without.

In openSUSE Tumbleweed (Plasma 5.23.5) the issue is a bit different: instead of the jumping window we have a jumping mouse pointer. The pointer suddenly jumps to the top left corner of the window, whereas the window itself stays where it is.

EXPECTED RESULT
The window should smoothly follow the mouse pointer when dragging. Neither the window nor the pointer should jump to a different location.

REPRODUCIBILITY
In principle the problem is always reproducible, but not always with the same applications on the same distribution, so please try all of the three mentioned above if you don't see the problem immediately. E.g. Libre Office 6 seems not to be affected on Neon in contrast to Libre Office 7 on the openSUSE systems.

SOFTWARE/OS VERSIONS
Linux: KDE Neon user or testing 20220118, openSUSE Krypron or Tumbleweed from 22.01.2022,
KDE Plasma Version: 5.23.90 (5.23.5 in Tumbleweed)
KDE Frameworks Version: 5.91.0 (5.90.0 in Tumbleweed)
Qt Version: 5.15.2

ADDITIONAL INFORMATION
The Problem with the jumping mouse pointer first occured mid-2021 if I remember correctly. The jumping window case only happens in the current testing version of KDE.

Note that the problem doesn't show up if the window is dragged by the title bar.
Comment 1 Nate Graham 2022-01-23 19:28:08 UTC 
X11 or Wayland?
Comment 2 Philipp Maierhöfer 2022-01-23 20:00:37 UTC 
X11.

After a few more tests: the Wayland session seems not to be affected. I tested with Tumbleweed/Krypton+Wayland and the problem didn't occur. But on Neon I wasn't able to start the Wayland session at all.
Comment 3 Vlad Zahorodnii 2022-01-24 10:17:25 UTC 
> The jumping window case only happens in the current testing version of KDE.
this should be fixed

> The Problem with the jumping mouse pointer first occured mid-2021 if I remember correctly
just to clarify, this bug can't be reproduced on wayland, right? only x11?
Comment 4 Vlad Zahorodnii 2022-01-24 10:17:59 UTC 
updating the bug report status to waitingforinfo
Comment 5 Philipp Maierhöfer 2022-01-24 10:22:04 UTC 
Yes, on wayland the problem can't be reproduced. Only on X11. At least according to my tests.
Comment 6 Vlad Zahorodnii 2022-01-24 10:24:03 UTC 
Okay, that looks like a different issue, maybe the pointer is warped? Can you file a different bug report to make it easier to track issues. This one (Window jumps to differnet location when dragging it by the menu bar) should be already fixed.
Comment 7 Philipp Maierhöfer 2022-01-24 10:45:16 UTC 
Thanks, that was quick!

The jumping mouse pointer only occurs on 5.23.5, but is fixed in 5.23.90 (to me it looked like the jumping pointer bug may have evolved into the jumping window bug, hence the historic information). Does it make sense to file a bug that has already been fixed in a newer version (if the old version is not LTS)?

But if you say "just do it", I'll do it. :)
Comment 8 Vlad Zahorodnii 2022-01-24 11:18:10 UTC 
Okay, if the issue comes back in 5.24, please file a bug report.
Comment 9 Philipp Maierhöfer 2022-02-02 13:26:29 UTC 
Has this really been fixed? In neon-testing-20220201-1820 and neon-unstable-20220130-0332 the jumping window bug is still there.
Comment 10 Vlad Zahorodnii 2022-02-02 13:40:15 UTC 
(In reply to Philipp Maierhöfer from comment #9)
> Has this really been fixed? In neon-testing-20220201-1820 and
> neon-unstable-20220130-0332 the jumping window bug is still there.

It depends if neon ships kwin with the fix, it can still ship a bit older kwin.
Comment 11 Philipp Maierhöfer 2022-02-19 22:11:12 UTC 
This is still not fixed in 5.24.1.
Comment 12 Vlad Zahorodnii 2024-06-12 10:08:39 UTC 
I cannot reproduce the issue on X11 in plasma 6