presentation-time: don't send presented on discard

types/wlr_presentation_time.c

@@ -289,9 +289,11 @@ static void feedback_handle_output_present(struct wl_listener *listener,
 		return;
 	}
 
+	if (output_event->presented) {
 		struct wlr_presentation_event event = {0};
 		wlr_presentation_event_from_output(&event, output_event);
 		wlr_presentation_feedback_send_presented(feedback, &event);
+	}
 	wlr_presentation_feedback_destroy(feedback);
 }