compositor: Hold on to surface.frame requests until we assign an output

We can't just throw away the callback, so hold on to the requests until
we have an output for the surface.

compositor/compositor.c

@@ -278,6 +278,7 @@ wlsc_surface_create(struct wlsc_compositor *compositor,
 
 	pixman_region32_init(&surface->damage);
 	pixman_region32_init(&surface->opaque);
+	wl_list_init(&surface->frame_callback_list);
 
 	surface->buffer_destroy_listener.func = surface_handle_buffer_destroy;
 
@@ -1065,11 +1066,12 @@ WL_EXPORT void
 wlsc_surface_assign_output(struct wlsc_surface *es)
 {
 	struct wlsc_compositor *ec = es->compositor;
-	struct wlsc_output *output;
+	struct wlsc_output *output, *new_output;
 	pixman_region32_t region;
 	uint32_t max, area;
 	pixman_box32_t *e;
 
+	new_output = NULL;
 	max = 0;
 	wl_list_for_each(output, &ec->output_list, link) {
 		pixman_region32_init_rect(&region,
@@ -1080,10 +1082,17 @@ wlsc_surface_assign_output(struct wlsc_surface *es)
 		area = (e->x2 - e->x1) * (e->y2 - e->y1);
 
 		if (area >= max) {
-			es->output = output;
+			new_output = output;
 			max = area;
 		}
 	}
+
+	es->output = new_output;
+	if (!wl_list_empty(&es->frame_callback_list)) {
+		wl_list_insert_list(new_output->frame_callback_list.prev,
+				    &es->frame_callback_list);
+		wl_list_init(&es->frame_callback_list);
+	}
 }
 
 static void
@@ -1161,8 +1170,7 @@ surface_frame(struct wl_client *client,
 		wl_list_insert(es->output->frame_callback_list.prev,
 			       &cb->link);
 	} else {
-		wl_list_init(&cb->link);
-		wl_resource_destroy(&cb->resource, 0);
+		wl_list_insert(es->frame_callback_list.prev, &cb->link);
 	}
 }
 

compositor/compositor.h

@@ -270,6 +270,7 @@ struct wlsc_surface {
 	struct wlsc_output *output;
 	enum wlsc_surface_map_type map_type;
 	struct wlsc_output *fullscreen_output;
+	struct wl_list frame_callback_list;
 
 	EGLImageKHR image;