desktop background wrong resolution on multi monitor setup

[Espen Skagerak]

With a multi monitor setup, all desktop backgrounds will be down scaled to match the built in display on a laptop (possibly the default display on any setup), resulting in blurred wallpapers on high resolution external monitors.

deactivating the built in display will show background in full resolution on an external monitor, and eventually enabling the built in display again, will show both backgrounds at full resolution again. however, after a reboot/login, the external display background is downscaled again.

attached files show what a high resolution external display looks like if the built in display has a very low resolution.

to re-create:
must have dual monitor setup.
set screen resolution on default display (laptop) to very low
set resolution to external display to a very high resolution
apply a desktop background
save
login/logout

[Espen Skagerak (c-espen)]

Also worth noting is that the login screen on ubuntu is not affected by this bug.

[Amr Ibrahim (amribrahim1987)]

Thanks for helping making Ubuntu better!

In the future, please use "ubuntu-bug package-name" to file Ubuntu bugs.
https://help.ubuntu.com/community/ReportingBugs#How_to_report_bugs