ksmserver-switchuser-greeter only reacts on the second click to "Switch".
xorg-session.log contains "lock called" followed by "could not establish screen lock" when it does not work, but only "lock called" when it does work.
This points to the greeter not ungrabbing mouse/keyboard properly before starting the screenlocker.
Git commit 1eb9ae7e33e2b0cb14ab10bc81710fa4b8f19ef5 by Fabian Vogt.
Committed on 25/02/2018 at 20:23.
Pushed by fvogt into branch 'Plasma/5.12'.
Fix the userswitcher when using the mouse for switching
Clicking on a button makes Qt grab the pointer, which means the screen can't be
locked. As we wait for the screen to be locked before switching, this never
Previously the userswitcher only worked on every second try, now it works
always on the first click.
Reviewers: #plasma, broulik
Reviewed By: #plasma, broulik
Subscribers: ngraham, plasma-devel
Differential Revision: https://phabricator.kde.org/D10802
M +2 -0 ksmserver/switchuserdialog.cpp