Bug 464850 - "Change Background" in System Settings' Login Screen(SDDM) not work properly and truncate /etc/sddm.conf
Summary: "Change Background" in System Settings' Login Screen(SDDM) not work properly ...
Status: REPORTED
Alias: None
Product: systemsettings
Classification: Applications
Component: kcm_sddm (show other bugs)
Version: 5.26.5
Platform: Fedora RPMs Linux
: NOR major
Target Milestone: ---
Assignee: David Edmundson
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2023-01-26 12:02 UTC by jackyzy823
Modified: 2023-08-05 06:14 UTC (History)
6 users (show)

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


Attachments
Image for Step 4 (347.49 KB, image/png)
2023-01-26 12:02 UTC, jackyzy823
Details

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Description jackyzy823 2023-01-26 12:02:39 UTC
Created attachment 155663 [details]
Image for Step 4

SUMMARY

"Change Background" in System Settings' Login Screen(SDDM) not work properly and truncate /etc/sddm.conf

STEPS TO REPRODUCE
1. Open System Settings
2. Navigate to Login Screen(SDDM)
3. Click on "Change Background" Button over SDDM themes
4. The "Change Background" do not fully show up (only two buttons are shown )  See attachment : in the right-buttom part, these two buttons display above other buttons.
5. At the meanwhile the cpu usage become higher
6. Then Press key `Esc` , After about 1s (not very immediately) , The "Change Background" UI appears
7. Then do the normal change background operation.
8. The `/etc/sddm.conf` become empty  After click `Apply` Button  and a file `/etc/sddm.conf.d/kde_settings.conf` is generated
9. Then Reboot , the sddm became a weird Virtual Keyboard UI (probably caused by the empty /etc/sddm.conf file) .

My fix
1. I have to reinstall `sddm` package to restore `/etc/sddm.conf`
2. change background via editing `/usr/share/sddm/themes/<theme name>/theme.conf.user`


OBSERVED RESULT
1. Change Background UI not work properly
2. /etc/sddm.conf is truncated. (That's a severe bug) 
3. After reboot ,sddm became a weird Virtual Keyboard UI (after some search, i found it may be maliit)

EXPECTED RESULT
1. The "Change background" UI appears normally.
1. The background of SDDM change successfully after a reboot.

SOFTWARE/OS VERSIONS

Linux/KDE Plasma: Fedora 37
(available in About System)
KDE Plasma Version: 5.26.5
KDE Frameworks Version: 5.102.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
Comment 1 Nate Graham 2023-01-27 20:24:22 UTC
The visual glitch should be fixed in 5.27, at least.
Comment 2 prinon 2023-08-05 06:14:42 UTC
(In reply to Nate Graham from comment #1)
> The visual glitch should be fixed in 5.27, at least.

Unfortunately the bug is not fixed in 5.27.7 (nor even the visual one).