Bug 450539

Summary:	[struts - kwin] - windows resize faulty for some multiple screen layouts
Product:	[Plasma] kwin	Reporter:	Riccardo Robecchi <sephiroth_pk>
Component:	multi-screen	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED UNMAINTAINED
Severity:	normal	CC:	xaver.hugl
Priority:	NOR
Version First Reported In:	6.3.2
Target Milestone:	---
Platform:	Neon
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Riccardo Robecchi 2022-02-18 21:21:05 UTC

SUMMARY
Plasma 5.24 introduced bug 431136, which made me notice that Latte appears to resize the screen area when multiple screens are connected. This makes window become squashed when I attach another screen (e.g. I connect my laptop to the docking station) or when I wake it up from suspension, up to the point where there's only the titlebar visible. I pinned this down to Latte as disabling it makes the issue disappear.

This may be linked to bug 442524 as the behaviour is similar, just in a different context.

STEPS TO REPRODUCE
1. Suspend the computer when there are more than one screen
2. Wake the computer
OR
1. Connect a new screen

OBSERVED RESULT
The open windows are squashed to a very small size.

EXPECTED RESULT
The open windows do not change their size.

SOFTWARE/OS VERSIONS
Linux: KDE neon
KDE Plasma Version: 5.24.1
KDE Frameworks Version: 5.90.0
Qt Version: 5.15.3

ADDITIONAL INFORMATION

Comment 1 Michail Vourlakos 2022-02-18 21:29:16 UTC

kwin bug nothing related to Latte... KWin promises to respect the struts from AlwaysVisible panels. You will have the same issue with plasma panels also... that makes it a kwin issue.

Comment 2 Riccardo Robecchi 2022-02-18 21:38:06 UTC

> Plasma 5.24 introduced bug 431136
I pasted the wrong bug number. The correct one is bug 449924.

(In reply to Michail Vourlakos from comment #1)
> kwin bug nothing related to Latte... KWin promises to respect the struts
> from AlwaysVisible panels. You will have the same issue with plasma panels
> also... that makes it a kwin issue.

I don't doubt that the problem originally stems from KWin and that's why I have opened a bug report against that, but the thing is that, as I wrote, the problem is not there with Plasma panels. I know this because I have tested it multiple times. It simply does not happen if I quit Latte and I have panels on all screens, just like I have Latte docks on all screens.

Comment 3 Michail Vourlakos 2022-02-19 06:38:15 UTC

(In reply to Riccardo Robecchi from comment #2)
> > Plasma 5.24 introduced bug 431136
> I pasted the wrong bug number. The correct one is bug 449924.
> 

this bug points to wayland, your issue is with x11 or wayland?

Comment 4 Riccardo Robecchi 2022-02-19 11:28:21 UTC

(In reply to Michail Vourlakos from comment #3)
> (In reply to Riccardo Robecchi from comment #2)
> > > Plasma 5.24 introduced bug 431136
> > I pasted the wrong bug number. The correct one is bug 449924.
> > 
> 
> this bug points to wayland, your issue is with x11 or wayland?

It actually appears to involve both X11 and Wayland. I originally opened it against X11 and someone else pointed out that it is present in Wayland as well.
I only use X11, so this bug is with X11. I don't know if this also applies to Wayland and I have no way of verifying it (the Wayland session doesn't work on my machine).

Comment 5 Michail Vourlakos 2022-02-20 15:35:46 UTC

Some comments in order for everyone to understand what is going on and why this should be fixed in kwin.

In all tested cases latte is sending correct struts to KWin, no idea why kwin decides to fail for some latte cases even though it looks like as if it succeeds with plasma panels. In the past I had tried to disable Always Visible behavior for some latte panels in some specific scenarios. This is no more the case, as long as kwin promises to handle this correctly at all cases Latte respects that....

For anyone to point fixes or way to handle this etc. etc... feel free to do so...