Summary:
The screenlock fails on X11 if it can't grab the keyboard.
We can't nicely solve the generic case. We can solve the common case of
a kwin effect being active.
It's not critical, arguably not even desirable to have these effects
persist after the screen is locked through an external trigger. We can
just close the effect early.
Key grabs have to be relased early before the close animation completes
so that the locker doesn't have a race based on animation times.
It's not ideal, but no worse than the current state for not much work.
BUG: 234153
Test Plan:
locked screen on a timer
opened various effects
Reviewers: #kwin, zzag
Reviewed By: #kwin, zzag
Subscribers: ngraham, zzag, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D20890
3604aaf74c