To be honest, I’m not entirely sure where the race condition originates
from, but when making sure that there are no pending events
(which is what sync_with_i3 accomplishes) before warping the pointer, we
have less flaky testsuite runs.
closes#1189
When focusing/moving to outputs, the method of getting the correct
output for a given container fails if the container in question is
floating and only partially mapped on an output screen. This patch
introduces a fail-safe retrieval of the output for any container.
