Bug 426591

Summary: Plasma doesn't respect resolution for wallpaper. Splash screen is in other resolution and desktop objects are misaligned
Product: [Plasma] plasmashell Reporter: Nick Stefanov <mo78>
Component: generalAssignee: David Edmundson <kde>
Status: RESOLVED DUPLICATE    
Severity: normal CC: nate, plasma-bugs
Priority: NOR    
Version: 5.19.5   
Target Milestone: 1.0   
Platform: Other   
OS: Linux   
See Also: https://bugs.kde.org/show_bug.cgi?id=426496
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Nick Stefanov 2020-09-16 08:00:14 UTC 
SUMMARY
Plasma doesn't respect resolution for wallpaper. My resolution is lower than the native one for my monitor. I use 1280x800 but the wallpaper is 1920x1080. The result is I see wallpaper's upper left corner. Positioning is Scaled and Cropped but this doesn't work at all. I tried all positioning options to no avail.

https://i.imgur.com/4O3IdTb.png

When I enter in Customize Layout mode, the upper options pannel is misaligned. It's not in the middle but in right and I can't close it:

https://i.imgur.com/IjLYnq0.png

Despite the resolution set (1280x800), when I restart the PC, the splash screen uses my native monitor resolution (2560x1440) and then, when it comes to desktop, it switches to 1280x800 and I think this is the culprit.

I use Display Port interface and tried to HDMI - same result. I tried different DEs like Deepin, Xfce, Cinnamon and MATE on the same machine with the same profile and all of them are working fine. It's just Plasma. I tried latest NVIDIA Vulkan beta drivers to no avail. I deleted all video settings and xorg.conf, changing resolutions from Display Settings and NVIDIA panel - nothing helps.

The only way I found to scale the wallpaper is 

kquitapp5 plasmashell && kstart5 plasmashell

Then the wallpaper is looking fine:

https://i.imgur.com/ZTHXT3f.png

Edit mode too:

https://i.imgur.com/PUBzUTC.png

STEPS TO REPRODUCE
1. Set resolution lower than the monitor's native resolution.
2. 
3. 

OBSERVED RESULT
The splash screen is still in native resolution and it switches to wanted resolution later. Some objects and the wallpaper are misaligned.

EXPECTED RESULT
Splash screen have to use the resolution that user set in Display settings. Wallpaper have to be whole, not part of it. Opjects shouldn't misaligned.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma
KDE Plasma Version: 5.19.5
KDE Frameworks Version: 5.74
Qt Version: 5.15.1
Comment 1 David Edmundson 2020-09-16 08:18:31 UTC 

*** This bug has been marked as a duplicate of bug 426496 ***
Comment 2 Nick Stefanov 2020-09-16 08:34:33 UTC 
Hello,
I don't use multiple monitors setup. It's just a single monitor so I think it's not a duplicate.
Comment 3 David Edmundson 2020-09-16 08:48:34 UTC 
KScreen kicks in and adjusts things (in your case just to lower the resolution). Somewhere our internal state gets messed up.

Sounds identical.
Comment 4 Nick Stefanov 2020-09-16 09:02:15 UTC 
It doesn't adjusts things. I just use it to start NVIDIA panel or to start Display settings to change to a different resolution and turn back to my resolution which temporary fixes the problem.
Comment 5 Nick Stefanov 2020-09-16 18:26:47 UTC 
I downgraded to Qt 5.15 and now wallpaper and edit menu are ok. Splash screen is still in natibe resolution though.
Comment 6 Nick Stefanov 2020-09-16 18:26:59 UTC 
Native*
Comment 7 Nate Graham 2020-09-18 23:49:38 UTC 
Ugh another screen-based Qt regression. :/ Reminds me of Bug 426496. Maybe not the same issue, but I bet the same thing that broke in Qt broke this too.
Comment 8 Nate Graham 2020-09-18 23:50:11 UTC 
So yeah, very likely a duplicate of Bug 426496 via being the same root cause, since  you confirmed that downgrading to Qt 5.15.0 fixes it.

*** This bug has been marked as a duplicate of bug 426496 ***
Comment 9 Nick Stefanov 2020-09-19 07:32:12 UTC 
But downgrading Qt doesn't help. Splash screen different resolution problem is ancient :)
Comment 10 Nate Graham 2020-09-21 04:33:31 UTC 
But you said "I downgraded to Qt 5.15 and now wallpaper and edit menu are ok."

And if "Splash screen different resolution problem is ancient :)"< then it wouldn't be affected by the Qt bug, right?
Comment 11 Nick Stefanov 2020-09-21 07:55:38 UTC 
Nope. Downgrade doesn't help. I recal it is here for very long time and it's not related to this bug, sorry.
Comment 12 Nate Graham 2020-09-21 15:52:49 UTC 
...But you said "I downgraded to Qt 5.15 and now wallpaper and edit menu are ok.".

Was that an incorrect statement? I'm confused. :/
Comment 13 Nick Stefanov 2020-09-21 18:00:27 UTC 
With 5.15.1 the wallpaper is partially represent - upper left corner, not the whole picture. With 5.15.1 when I enter edit panel mode the upper menu is half invisible for it is moved to the upper left corner as though the resolution is native but it isn't. The system just doesn't realise that I'm on lower resolution and represents and places the wallpaper and edit menu as if the native resolution.

With 5.15.0 both of the problems are fixed. 

The splashctreen is with native resolution with both 5.15.1 and 5.15.0 and may be 10 versions backwards :)
Comment 14 Nate Graham 2020-09-21 20:03:46 UTC 
> With 5.15.0 both of the problems are fixed. 
Then it is indeed the same problem as in Bug 426496. :) Let's continue the conversation there.
Comment 15 Nick Stefanov 2020-09-21 20:34:24 UTC 
But I have a single monitor setup...
Comment 16 Nate Graham 2020-09-21 20:35:48 UTC 
It doesn't matter, the bug in question affects single-monitor setups too, not just dual monitor ones.