check_obj_resize() in sub/osd.c calls mp_client_broadcast_event(), which
calls notify_property_events(). This is pretty unexpected, because
check_obj_resize() may be called from the VO thread. While that's sort
of awful, it seems to be OK locking-wise. But it breaks an assumption in
notify_property_events() that the core doesn't need to be woken up,
which could possibly lead to a missed/delayed property update (although
rather unlikely).
Fix this by explicitly waking up the core when it's called from the OSD
code.
4a65c22c50