Destroy sub-surfaces with parent layer-shell surface

Closes: https://github.com/swaywm/sway/issues/6337

include/sway/layers.h

@@ -25,6 +25,8 @@ struct sway_layer_surface {
 	bool mapped;
 	struct wlr_box extent;
 	enum zwlr_layer_shell_v1_layer layer;
+
+	struct wl_list subsurfaces;
 };
 
 struct sway_layer_popup {
@@ -44,6 +46,7 @@ struct sway_layer_popup {
 struct sway_layer_subsurface {
 	struct wlr_subsurface *wlr_subsurface;
 	struct sway_layer_surface *layer_surface;
+	struct wl_list link;
 
 	struct wl_listener map;
 	struct wl_listener unmap;

sway/desktop/layer_shell.c

@@ -352,6 +352,8 @@ static void unmap(struct sway_layer_surface *sway_layer) {
 		sway_layer->layer_surface->surface, true);
 }
 
+static void layer_subsurface_destroy(struct sway_layer_subsurface *subsurface);
+
 static void handle_destroy(struct wl_listener *listener, void *data) {
 	struct sway_layer_surface *sway_layer =
 		wl_container_of(listener, sway_layer, destroy);
@@ -360,6 +362,12 @@ static void handle_destroy(struct wl_listener *listener, void *data) {
 	if (sway_layer->layer_surface->mapped) {
 		unmap(sway_layer);
 	}
+
+	struct sway_layer_subsurface *subsurface, *subsurface_tmp;
+	wl_list_for_each_safe(subsurface, subsurface_tmp, &sway_layer->subsurfaces, link) {
+		layer_subsurface_destroy(subsurface);
+	}
+
 	wl_list_remove(&sway_layer->link);
 	wl_list_remove(&sway_layer->destroy.link);
 	wl_list_remove(&sway_layer->map.link);
@@ -428,11 +436,8 @@ static void subsurface_handle_commit(struct wl_listener *listener, void *data) {
 	subsurface_damage(subsurface, false);
 }
 
-static void subsurface_handle_destroy(struct wl_listener *listener,
-		void *data) {
-	struct sway_layer_subsurface *subsurface =
-			wl_container_of(listener, subsurface, destroy);
-
+static void layer_subsurface_destroy(struct sway_layer_subsurface *subsurface) {
+	wl_list_remove(&subsurface->link);
 	wl_list_remove(&subsurface->map.link);
 	wl_list_remove(&subsurface->unmap.link);
 	wl_list_remove(&subsurface->destroy.link);
@@ -440,6 +445,13 @@ static void subsurface_handle_destroy(struct wl_listener *listener,
 	free(subsurface);
 }
 
+static void subsurface_handle_destroy(struct wl_listener *listener,
+		void *data) {
+	struct sway_layer_subsurface *subsurface =
+			wl_container_of(listener, subsurface, destroy);
+	layer_subsurface_destroy(subsurface);
+}
+
 static struct sway_layer_subsurface *create_subsurface(
 		struct wlr_subsurface *wlr_subsurface,
 		struct sway_layer_surface *layer_surface) {
@@ -451,6 +463,7 @@ static struct sway_layer_subsurface *create_subsurface(
 
 	subsurface->wlr_subsurface = wlr_subsurface;
 	subsurface->layer_surface = layer_surface;
+	wl_list_insert(&layer_surface->subsurfaces, &subsurface->link);
 
 	subsurface->map.notify = subsurface_handle_map;
 	wl_signal_add(&wlr_subsurface->events.map, &subsurface->map);
@@ -643,6 +656,8 @@ void handle_layer_shell_surface(struct wl_listener *listener, void *data) {
 		return;
 	}
 
+	wl_list_init(&sway_layer->subsurfaces);
+
 	sway_layer->surface_commit.notify = handle_surface_commit;
 	wl_signal_add(&layer_surface->surface->events.commit,
 		&sway_layer->surface_commit);