Display settings mess up when screens rearranged in xfce-display-settings

[Patrick Dunford]

I have a Dell 1280x1024 19" screen and Sony 1366x768 32" screen. Due to the ports they are connected to on the video card they appear by default in xfce-display-settings in the reverse to their physical layout.

On previous versions of Xubuntu there has not been any problem with rearranging the display order. On artful I can only get things to work properly if I leave the display order to the default.

If I try to rearrange the display order on artful all sorts of weird things happen. The 19" screen only uses two thirds of its vertical height to display the picture, the rest is drawn as white. The taskbar disappears completely. The mouse has to be on the opposite screen to the one where you are working in order to be able to click on anything.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: xorg 1:7.7+19ubuntu1
ProcVersionSignature: Ubuntu 4.10.0-26.30-generic 4.10.17
Uname: Linux 4.10.0-26-generic x86_64
ApportVersion: 2.20.5-0ubuntu5
Architecture: amd64
CurrentDesktop: XFCE
Date: Sun Jul 16 16:27:49 2017
InstallationDate: Installed on 2017-07-16 (0 days ago)
InstallationMedia: Xubuntu 17.10 "Artful Aardvark" - Alpha amd64 (20170704)
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)

[Patrick Dunford (kahukowhai)]

Done some more playing and swapped the screens ports around on the card to make it detect in the same order as I want them on the screen. It basically doesn't cope with screens that have different resolutions vertically. Attached picture of the supported positioning of the two screens.

[Patrick Dunford (kahukowhai)]

And here is the configuration that doesn't work. If I apply this the Dell screen will have a part of it that is duplicated from the Sony screen, the taskbar and even the mouse position will be offset from this duplicate part (will try to get a screenshot of it)

[Patrick Dunford (kahukowhai)]

A bit more testing shows completely random results each time the second configuration is applied. For example this picture shows the problems now occurring on the Sony screen rather than the Dell screen.

The biggest effect seen on the Sony screen in this instance included mouse position offset where the mouse is registering in a different place from where the pointer is.

As soon as I was able to restore the original configuration everything works fine.

Attachment showing the messed up display. The computer had just been restarted and there were no programs running, so the stuff displayed in the top section of the screen was not from any running applications.

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 17.10 (artful) reached end-of-life on July 19, 2018.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed.