backend/wayland: reset active pointer on destroy

backend/wayland/pointer.c

@@ -404,6 +404,9 @@ static void destroy_pointer(struct wlr_wl_pointer *pointer) {
 	if (pointer->output->cursor.pointer == pointer) {
 		pointer->output->cursor.pointer = NULL;
 	}
+	if (pointer->seat->active_pointer == pointer) {
+		pointer->seat->active_pointer = NULL;
+	}
 
 	wlr_pointer_finish(&pointer->wlr_pointer);
 	wl_list_remove(&pointer->output_destroy.link);