osd: fix possible misses of osd-dimensions property updates

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.

player/client.c

@@ -779,6 +779,17 @@ void mp_client_broadcast_event(struct MPContext *mpctx, int event, void *data)
     pthread_mutex_unlock(&clients->lock);
 }
 
+// Like mp_client_broadcast_event(), but can be called from any thread.
+// Avoid using this.
+void mp_client_broadcast_event_external(struct mp_client_api *api, int event,
+                                        void *data)
+{
+    struct MPContext *mpctx = api->mpctx;
+
+    mp_client_broadcast_event(mpctx, event, data);
+    mp_wakeup_core(mpctx);
+}
+
 // If client_name == NULL, then broadcast and free the event.
 int mp_client_send_event(struct MPContext *mpctx, const char *client_name,
                          uint64_t reply_userdata, int event, void *data)

player/client.h

@@ -39,6 +39,9 @@ struct mpv_global *mp_client_get_global(struct mpv_handle *ctx);
 struct MPContext *mp_client_get_core(struct mpv_handle *ctx);
 struct MPContext *mp_client_api_get_core(struct mp_client_api *api);
 
+void mp_client_broadcast_event_external(struct mp_client_api *api, int event,
+                                        void *data);
+
 // m_option.c
 void *node_get_alloc(struct mpv_node *node);
 

sub/osd.c

@@ -242,7 +242,7 @@ static void check_obj_resize(struct osd_state *osd, struct mp_osd_res res,
 {
     if (!osd_res_equals(res, obj->vo_res)) {
         obj->vo_res = res;
-        mp_client_broadcast_event(mp_client_api_get_core(osd->global->client_api),
+        mp_client_broadcast_event_external(osd->global->client_api,
                                            MP_EVENT_WIN_RESIZE, NULL);
     }
 }