Bug 425185

Summary:	Display Configuration allows to replicate screen for turned off screen
Product:	[Applications] systemsettings	Reporter:	Piotr Mierzwinski <piotr.mierzwinski>
Component:	kcm_kscreen	Assignee:	kscreen-bugs-null <kscreen-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	nate, piotr.mierzwinski, plasma-bugs-null
Priority:	NOR
Version First Reported In:	5.19.4
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Display Settings with only one screen

Description Piotr Mierzwinski 2020-08-10 10:54:41 UTC

SUMMARY
I have multi monitors configuration (monitor+projector and both connected via HDMI), but do to not correct support in Linux distribution or DE itself (turned off screen connected via HDMI is treated as normally working and considered by Plasma to display content) I turned it off by xrandr (command: xrandr --output HDMI2 --off). Despite this screen is not enabled (in kscreen) Display Configuration allows to replicate primary screen with this turned off. 
Note that 'Display Settings' doesn't show turned off screen, but allows to select it to replication.
Check details in screenshot. 

STEPS TO REPRODUCE
Prerequisite: need to have multi (at least 2) monitors configuration
1. Replication of screen turned off
1. Turn off one screen by xrandr 
2. Open Display Configuration and check option: 'Replica of:' 
3. 

OBSERVED RESULT
Is possible to select turned off screen

EXPECTED RESULT
Should not be possible to select turned off screen to replication

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: YES
(available in About System)
KDE Plasma Version: 5.19.4
KDE Frameworks Version: 5.73
Qt Version: 5.15

ADDITIONAL INFORMATION

Comment 1 Piotr Mierzwinski 2020-08-10 10:58:50 UTC

Created attachment 130750 [details]
Display Settings with only one screen

Comment 2 Nate Graham 2022-11-10 22:11:42 UTC

When you turned it off using xrandr, KScreen probably didn't reload in real-time to show this. Did you leave the page and come back to it? If not, this is probably the same issue as Bug 420827.

Comment 3 Piotr Mierzwinski 2022-11-15 23:33:37 UTC

(In reply to Nate Graham from comment #2)
> When you turned it off using xrandr, KScreen probably didn't reload in
> real-time to show this. Did you leave the page and come back to it? If not,
> this is probably the same issue as Bug 420827.

Seems the issue is the same as described in mentioned bug.

Off topic.
Would be nice if would be possible edit saved/added posts, because after a typo or different mistake will be found in original message there is need to add another message, which for sure decreases readability bug report, IMHO.

*** This bug has been marked as a duplicate of bug 420827 ***