noop: listen to display destroy and destroy the backend

backend/noop/backend.c

@@ -39,6 +39,8 @@ static void backend_destroy(struct wlr_backend *wlr_backend) {
 
 	wlr_signal_emit_safe(&wlr_backend->events.destroy, backend);
 
+	wl_list_remove(&backend->display_destroy.link);
+
 	free(backend);
 }
 
@@ -47,6 +49,12 @@ static const struct wlr_backend_impl backend_impl = {
 	.destroy = backend_destroy,
 };
 
+static void handle_display_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_noop_backend *noop =
+		wl_container_of(listener, noop, display_destroy);
+	backend_destroy(&noop->backend);
+}
+
 struct wlr_backend *wlr_noop_backend_create(struct wl_display *display) {
 	wlr_log(WLR_INFO, "Creating noop backend");
 
@@ -60,6 +68,9 @@ struct wlr_backend *wlr_noop_backend_create(struct wl_display *display) {
 	backend->display = display;
 	wl_list_init(&backend->outputs);
 
+	backend->display_destroy.notify = handle_display_destroy;
+	wl_display_add_destroy_listener(display, &backend->display_destroy);
+
 	return &backend->backend;
 }
 

include/backend/noop.h

@@ -10,6 +10,8 @@ struct wlr_noop_backend {
 	struct wl_list outputs;
 	size_t last_output_num;
 	bool started;
+
+	struct wl_listener display_destroy;
 };
 
 struct wlr_noop_output {