It's possible that a non-default keyboard grab exists when we are trying
to change focus. For example, say there is an XDG popup when we click on
a different window. This popup's keyboard grab will swallow any
keyboard_notify_enter(), meaning the newly-clicked window won't receive
keyboard input.
So, we cancel any existing grabs in roots_seat_set_focus(). Before this
fix, a window would have been set as active but not receive keyboard
entry.
Fixes#233.
Signed-off-by: Genki Sky <sky@genki.is>
28d718c0dd