Assert (almost all) signals have no attached listeners on destroy

render/allocator/allocator.c

@@ -28,6 +28,7 @@ void wlr_allocator_init(struct wlr_allocator *alloc,
 		.impl = impl,
 		.buffer_caps = buffer_caps,
 	};
+
 	wl_signal_init(&alloc->events.destroy);
 }
 
@@ -173,6 +174,9 @@ void wlr_allocator_destroy(struct wlr_allocator *alloc) {
 		return;
 	}
 	wl_signal_emit_mutable(&alloc->events.destroy, NULL);
+
+	assert(wl_list_empty(&alloc->events.destroy.listener_list));
+
 	alloc->impl->destroy(alloc);
 }
 

render/drm_syncobj.c

@@ -241,7 +241,8 @@ bool wlr_drm_syncobj_timeline_waiter_init(struct wlr_drm_syncobj_timeline_waiter
 }
 
 void wlr_drm_syncobj_timeline_waiter_finish(struct wlr_drm_syncobj_timeline_waiter *waiter) {
-	wl_list_remove(&waiter->events.ready.listener_list);
+	assert(wl_list_empty(&waiter->events.ready.listener_list));
+
 	wl_event_source_remove(waiter->event_source);
 	close(waiter->ev_fd);
 }

render/wlr_renderer.c

@@ -51,6 +51,9 @@ void wlr_renderer_destroy(struct wlr_renderer *r) {
 
 	wl_signal_emit_mutable(&r->events.destroy, r);
 
+	assert(wl_list_empty(&r->events.destroy.listener_list));
+	assert(wl_list_empty(&r->events.lost.listener_list));
+
 	if (r->impl && r->impl->destroy) {
 		r->impl->destroy(r);
 	} else {