Bug 512553

Summary: Mouse clicks go to wrong window for X11 apps
Product: [Plasma] kwin Reporter: Tim Hutt <tdhutt>
Component: coreAssignee: KWin default assignee <kwin-bugs-null>
Status: REPORTED ---    
Severity: normal    
Priority: NOR    
Version First Reported In: 6.4.5   
Target Milestone: ---   
Platform: Kubuntu   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Tim Hutt 2025-11-24 11:30:14 UTC
Since upgrading from Kubuntu 25.04 to 25.10 I have a very weird issue. When I have multiple ETX windows open (ETX is a proprietary remote desktop solution that supports seamless mode), if they overlap then mouse clicks can go to the *bottom* window. Sometimes it seems to send a mouse click to the bottom window and then the top window immediately afterwards (from just clicking once). It's very weird.

ETX uses X11, and this happens in both the X11 and Wayland sessions. It *didn't* happen on Kubuntu 25.04 (not sure exactly which Plasma version that uses).

Is there any way I can debug this? It's very annoying!
Comment 1 Vlad Zahorodnii 2025-12-10 14:41:10 UTC
> Is there any way I can debug this?

`xwininfo -tree -root` might be worth running
Comment 2 Tim Hutt 2025-12-17 10:51:29 UTC
I get this:

```
     0x2006e5 (has no name): ()  3840x1528+0+28  +0+28
        1 child:
        0x2006e6 (has no name): ()  3840x1528+0+0  +0+28
           1 child:
           0x3000403 "iceni-coreip": ("code" "Code")  3840x1528+0+0  +0+28
     0x2006e9 (has no name): ()  3840x1528+0+28  +0+28
        1 child:
        0x2006ea (has no name): ()  3840x1528+0+0  +0+28
           1 child:
           0x30005af "Design Browser 1 - SimVision": ("watchList0" "WatchList")  3840x1528+0+0  +0+28
              1 child:
              0x30005b3 (has no name): ()  3840x1528+0+0  +0+28
                 6 children:
                 0x3000922 (has no name): ()  3840x1528+0+0  +0+28
                 0x3000642 (has no name): ()  3840x28+0+1500  +0+1528
                    1 child:
```

The two windows are `iceni-coreip` and `Design Browser 1` (which is using Motif or Tk or something that has a ton of native child X windows but I don't think that's relevant).

They're both fullscreen, `iceni-coreip` is visually on top (which is correct) but clicks go to `Design Browser 1`.

I can't see anything wrong here tbh. Unfortunately it doesn't seem to include the Z height (or whatever Wayland/X uses) in this output. What can I try next?