Fix vnc configuration on wayland

[zzambers]

There are test failures in wayland jobs on our infra. After further investigation, I have found, that windows of some programs (eclipse, jmc) do not show up in vnc, but directly on desktop. Seems like these are using SWT, which in turn uses GTK and defaults to wayland.

This should fix that problem and make all windows use x11 display of vnc (on wayland desktop).

[judovana]

This should fix that problem and make all windows use x11 display of vnc (on wayland desktop).

... instead of wayland? Maybe limit this to swt apps only?

[zzambers]

This should fix that problem and make all windows use x11 display of vnc (on wayland desktop).

... instead of wayland? Maybe limit this to swt apps only?

I have realized that vnc is not be used, when display is set. However all windows interesting to us still have to use x11, because import can only capture x11 ones (wayland gui is invisible to it). So this workaround is required always when wayland is used, not only for vnc (I need to fix that).

Anyway, maybe it makes sense to do this for swt apps only, I'll think about it.

[judovana]

It seems that you have thought about it ;)

[zzambers]

Sorry I made another branch with different change, but forgot to commit it, and force-pushed it. So there were no new commits and it auto closed PR. Reopened :)

[zzambers]

It seems that you have thought about it ;)

Yes, it is probably good idea do it this way :)

[judovana]

Thanx. Jsut to clarify - now all tests are running via X, through vnc even if there is jsut wayland compositor. And it is not a regrerssion, becasue the vnc was always X only. Right?

[zzambers]

Thanx. Jsut to clarify - now all tests are running via X, through vnc even if there is jsut wayland compositor. And it is not a regrerssion, becasue the vnc was always X only. Right?

True, actually, I have found out, that import does not work on Xwayland, with confusing error message:

import -window root root.png
import: missing an image filename `root.png' @ error/import.c/ImportImageCommand/1276.

However as Xwayland is basically x11 server in "rootless" mode (i.e. without root window), it is not that surprising not being able to make screensot of root window:

tester      3015  0.0  0.6 196244 51888 ?        S    13:39   0:00 /usr/bin/Xwayland :0 -rootless -noreset -accessx -core -auth /run/user/1000/.mutter-Xwaylandauth.U9FZD3 -listenfd 4 -listenfd 5 -displayfd 6 -initfd 7

So I guess on wayland we need to stay on vnc (at least for now).

[judovana]

Thanx a lot for digging. Ok to merge after gh finishes.