The X11 selection source was being preserved after unsetting its
ownership. This is no leak as it would be eventually replaced by
another source, or destroyed on finalize. But it's pointless to
keep it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1206
Most visible with xwayland-on-demand, at the time of setting things up
for X11 selections, we don't forward the current state. This makes the
first started X11 app oblivious to eg. the current clipboard.
Syncing selections up at the time of initializing the X11 selection
stuff ensures that doesn't happen.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1186
This shouldn't happen frequently, but is just a sign that the source is
being replaced by something else. Just keep the warning for other possible
error situations.
Also, plug the potential GError leak.
Closes: https://gitlab.gnome.org/GNOME/mutter/issues/598
This code takes care of both setting up X11 selection sources whenever
X11 clients claim selection ownership, and claiming selection ownership
on a mutter X11 window whenever other selection sources claim ownership.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/320