backend/x11: flush after destroying window
Otherwise the destroy message is kept buffered and never reaches
the X11 server. Thanks X11.
@@ -52,6 +52,7 @@ static void output_destroy(struct wlr_output *wlr_output) {
wl_event_source_remove(output->frame_timer);
eglDestroySurface(x11->egl.display, output->surf);
xcb_destroy_window(x11->xcb_conn, output->win);
+ xcb_flush(x11->xcb_conn);
free(output);
}
