prelit_control is used for both prelight and pressed states, so the early
return in update_prelit_control() misses the case where prelit_control
already matches the control we are updating, but its state is PRESSED
rather than PRELIGHT. Fix the condition to not have pressed controls
linger around erroneously.
https://bugzilla.gnome.org/show_bug.cgi?id=731058
a7f083897f
