Bug 507446 - Reordering QDockWidgets causes the window to become uninteractible via cursor
Summary: Reordering QDockWidgets causes the window to become uninteractible via cursor
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: general (other bugs)
Version First Reported In: 6.4.3
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-07-24 14:39 UTC by Roke Julian Lockhart Beedell
Modified: 2025-08-14 17:08 UTC (History)
3 users (show)

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


Attachments
A Screencast That Depicts This (492.04 KB, video/webm)
2025-07-24 14:39 UTC, Roke Julian Lockhart Beedell
Details
Reproduction Logs In Dolphin On Desktop (1.21 MB, text/plain)
2025-07-28 16:23 UTC, Roke Julian Lockhart Beedell
Details
A Screencast That Demonstrates That The Breeze QStyle Is At Fault (3.69 MB, application/x-lzma)
2025-07-29 11:01 UTC, Roke Julian Lockhart Beedell
Details
Reproduction In A New `neon-user-20250727-0745.iso` VM (225.45 KB, video/webm)
2025-07-29 19:54 UTC, Roke Julian Lockhart Beedell
Details

Note You need to log in before you can comment on or make changes to this bug.
Description Roke Julian Lockhart Beedell 2025-07-24 14:39:36 UTC
Created attachment 183491 [details]
A Screencast That Depicts This

SUMMARY

When I reorder and/or merge QDockWidgets in Konsole and Dolphin, the window immediately becomes uninteractible with via my cursor thereafter, until the window has been reinitialised. This has been so since a few months ago, at least.

STEPS TO REPRODUCE

1. Invoke Dolphin or Konsole.

1. Move a QDockWidget from one side of the window to another, place it atop another, or hide another with it, so that they tab.

OBSERVED RESULT

I become thereafter unable to interact with the window via my cursor, but can via my keyboard.

EXPECTED RESULT

I should remain able to interact with the window.

SOFTWARE/OS VERSIONS

> ~~~
> Operating System: Fedora Linux 42
> KDE Plasma Version: 6.4.3
> KDE Frameworks Version: 6.16.0
> Qt Version: 6.9.1
> Kernel Version: 6.15.7-200.fc42.x86_64 (64-bit)
> Graphics Platform: Wayland
> Graphics Processor 1: AMD Radeon RX 5700
> Graphics Processor 2: AMD Radeon Graphics
> ~~~

ADDITIONAL INFORMATION

Might be vaguely related to https://bugzilla.redhat.com/show_bug.cgi?id=2366483#c5. Ascertained whilst authoring https://invent.kde.org/frameworks/kirigami/-/issues/81#note_1267782.
Comment 1 Roke Julian Lockhart Beedell 2025-07-24 14:40:14 UTC
> 1. Invoke Dolphin or Konsole.
> 
> 1. Move a QDockWidget from one side of the window to another, place it atop another, or hide another with it, so that they tab.

Should be 1, then 2. I'm so used to CommonMark, I occasionally forget. Apologies.
Comment 2 Roke Julian Lockhart Beedell 2025-07-24 14:43:57 UTC
(In reply to Roke Julian Lockhart Beedell from comment #0)

I've since ascertained that I remain able to move the QDockWidgets, so am merely unable to interact with all *else*.
Comment 3 Roke Julian Lockhart Beedell 2025-07-24 14:44:22 UTC
Additionally, I've reproduced on different hardware (albeit the same OS):

> ~~~
> Operating System: Fedora Linux 42
> KDE Plasma Version: 6.4.3
> KDE Frameworks Version: 6.16.0
> Qt Version: 6.9.1
> Kernel Version: 6.15.6-200.fc42.x86_64 (64-bit)
> Graphics Platform: Wayland
> Processors: 16 × AMD Ryzen 7 7840HS w/ Radeon 780M Graphics
> Memory: 32 GiB of RAM (30.6 GiB usable)
> Graphics Processor: AMD Radeon 780M Graphics
> Manufacturer: Framework
> Product Name: Laptop 16 (AMD Ryzen 7040 Series)
> System Version: A7
> ~~~

For comparison, the original report was on:

> ~~~
> Processors: 12 × AMD Ryzen 5 7600X 6-Core Processor
> Memory: 32 GiB of RAM (30.4 GiB usable)
> Manufacturer: ASRock
> Product Name: X670E Taichi
> ~~~

Maybe mark this as spam or whatever if it's uselessly tangential.
Comment 4 TraceyC 2025-07-25 02:38:35 UTC
In the screen recording - in Dolphin, dragged the Information panel from the left panel to the right panel, then back to the left panel
The window elements then stopped responding to clicks

Moving to kwin, which is responsible for windows
Comment 5 David Redondo 2025-07-28 07:07:07 UTC
Does this happen 100% of the time when you try it? I tried a bunch of time sand couldn't trigger it. If you could send me the output  of running WAYLAND_DEBUG=1 dolphin when this happens that could be helpful. It's probably very noisy so try to keep it to just reproducing the issue, thanks!
Comment 6 Roke Julian Lockhart Beedell 2025-07-28 16:23:17 UTC
Created attachment 183605 [details]
Reproduction Logs In Dolphin On Desktop

(In reply to David Redondo from comment #5)

Reproduced it about 5 times on my desktop. Logs are in the attached file. Note that this desktop installation is also afflicted with https://bugs.kde.org/show_bug.cgi?id=496876#c0, so if the logs on my laptop would have less false positives, I can provide that instead.
Comment 7 Roke Julian Lockhart Beedell 2025-07-28 16:24:07 UTC
(In reply to David Redondo from comment #5)

> Does this happen 100% of the time when you try it?

Yes, it reproduces 100% of the time, on both laptop and desktop.
Comment 8 David Redondo 2025-07-29 06:56:34 UTC
Thank you.
From that it seems that KWin correctly sends button events still at the end, whcih means the issue is client side -  either in Qt or Dolphin.
Comment 9 Roke Julian Lockhart Beedell 2025-07-29 11:01:55 UTC
Created attachment 183629 [details]
A Screencast That Demonstrates That The Breeze QStyle Is At Fault

(In reply to David Redondo from comment #8)

It can't be in Dolphin, since it affects Konsole too. Additionally, I realised today that it's probably not in KDE Frameworks, since it affects `qt6-designer-6.9.1-1.fc42.x86_64`. I considered whether KWin might be the cause at first, but you've ruled that out. That appears to leave solely the Breeze QStyle and Qt itself.

I never expected it to be the cause, but the QStyle does appear to be: when I switch to Fusion via `kcm_style`, I am able to move them as much as I want. The moment I switch back to Breeze, the previously interactible application becomes unresponsive.

https://youtu.be/wHrAXUVpUEA demonstrates, although I've also attached a compressed, H265 MPEG-4.
Comment 10 David Redondo 2025-07-29 13:18:53 UTC
Thank you that's good investigation.
Comment 11 TraceyC 2025-07-29 17:07:39 UTC
Notes from the video:
1. Dolphin, Terminal, Qt Widgets Designer, Application Style kcm open
  Dolphin panes - Folders and Places on left, Information on right
  Breeze app style is in use
2. Window elements in Dolphin and Qt Designer are highlighted under the mouse as it moves around as expected
3. Switched to Fusion app style
4. In QtWD moved the Widget Box from left to right, back to left, menus worked normally
5. In Dolphin, moved Folders from left to right, menus work normally. Moved Folders to the left
6. Same behavior in Konsole

Changed App Style to Breeze 

In Konsole
1. Menus work normally
2.  Moved Quick Commands from left to right, menus do not respond to mouse hover / click
3.  Moved Quick Commands back to the left menus still ignore the mouseappli
This can be replicated In Dolphin and Qt Widget Designer
Comment 12 TraceyC 2025-07-29 17:46:33 UTC
Following the above steps, I cannot replicate the same exact behavior with Plasma 6.4.3, Solus and Fedora 42

I do see, however, a slightly different behavior problem with different parts of the window not interacting correctly when switching the Global Theme or just the Application Style

1. Dolphin,Application Style kcm open
  Dolphin panes - Folders and Places on left, Information on right
  Breeze Dark global theme, Breeze app style is in use
2. Once I move the Information panel in Dolphin to the left, I can't move it to the right again.  I can still interact with the other window elements, unlike in the recording.
Restarting plasmashell and rebooting does not change this
3. Change Application Style to Fusion - no change, even after reboot
4. Change Global Theme to Layan - no change, even after reboot

Using the same steps  in git-master, I can't reproduce the original bug or the other one above
Step 2 - info pane can be moved multiple times, menus work properly
3.  Works OK
4. Works OK

Then
5. Change Application Style to Breeze - works OK

So it's possible that the underlying problem is fixed in git-master

Roke, do you have a system / VM with Neon Testing or another distro that runs on git-master that you can try to reproduce this on?
Comment 13 Roke Julian Lockhart Beedell 2025-07-29 19:54:57 UTC
Created attachment 183643 [details]
Reproduction In A New `neon-user-20250727-0745.iso` VM

(In reply to TraceyC from comment #12)

> Roke, do you have a system / VM with Neon Testing or another distro that runs on
> git-master that you can try to reproduce this on?

With a completely new Neon *Stable* libvirt VM, it reproduces (Unstable didn't work, per https://bugs.kde.org/show_bug.cgi?id=507644#c0). Its environment is:

> ~~~YAML
> Operating System: KDE neon User Edition
> KDE Plasma Version: 6.4.3
> KDE Frameworks Version: 6.16.0
> Qt Version: 6.9.1
> Kernel Version: 6.14.0-24-generic (64-bit)
> Graphics Platform: Wayland
> Processors: 6 × AMD Ryzen 5 7600X 6-Core Processor
> Memory: 15.8 GiB of RAM (15.4 GiB usable)
> Graphics Processor: llvmpipe
> Manufacturer: QEMU
> Product Name: Standard PC (Q35 + ICH9, 2009)
> System Version: pc-q35-9.2
> ~~~
Comment 14 TraceyC 2025-07-29 20:19:56 UTC
(In reply to Roke Julian Lockhart Beedell from comment #13)
> With a completely new Neon *Stable* libvirt VM, it reproduces 

Thanks. I was hoping for a test with a system that has git-master. I'll have to rebuild my Neon Testing VM, that broke itself.
Comment 15 David Redondo 2025-07-30 08:48:00 UTC
I downgraded my breeze to 6.4 and can't reproduce, I also couldnt spot any relevant commits in breeze between 6.4 and master.

Very curious
Comment 16 Bug Janitor Service 2025-08-14 03:46:24 UTC
🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

Thank you for helping us make KDE software even better for everyone!
Comment 17 Roke Julian Lockhart Beedell 2025-08-14 09:42:26 UTC
(In reply to Bug Janitor Service from comment #16)

I think this was for an already-answered question (https://bugs.kde.org/show_bug.cgi?id=507446#c12), so I'm changing it back to REPORTED. However, I believe it should be CONFIRMED by now.
Comment 18 TraceyC 2025-08-14 16:50:11 UTC
(In reply to Roke Julian Lockhart Beedell from comment #17)
> I think this was for an already-answered question
> (https://bugs.kde.org/show_bug.cgi?id=507446#c12), so I'm changing it back
> to REPORTED. However, I believe it should be CONFIRMED by now.

In that comment, I had asked for a test from Neon Testing, so the question had not yet been answered.
CONFIRMED would not be appropriate yet, until someone  else can reproduce this. See https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging#Reproduce_the_bug

I've now got a working Neon Testing VM. My results were the same as my attempt on Fedora, where I couldn't reproduce this bug specifically. On git-master, the results are also the same.
https://bugs.kde.org/show_bug.cgi?id=507446#c12

I'll leave this as REPORTED since we're not waiting on information.
Comment 19 Roke Julian Lockhart Beedell 2025-08-14 17:08:04 UTC
(In reply to TraceyC from comment #18)

Jan Grulich, a RedHat employee, reproduced it at https://bugzilla.redhat.com/show_bug.cgi?id=2366483#c5.
Comment 20 Roke Julian Lockhart Beedell 2025-08-14 17:08:35 UTC
(In reply to Roke Julian Lockhart Beedell from comment #19)

Sorry, wrong report. That's why I'd become confused. Apologies.