Fix issues preventing layer from getting allocated

Now all of the steps to get rootston a reference to the layer surface
are correctly wired up.

examples/layer-shell.c

@@ -21,7 +21,7 @@ struct wlr_egl_surface *egl_surface;
 struct wl_callback *frame_callback;
 
 static uint32_t output = 0;
-static uint32_t layer = -1;
+static uint32_t layer = ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND;
 static uint32_t anchor = 0;
 static uint32_t width = 256, height = 256;
 
@@ -98,7 +98,7 @@ int main(int argc, char **argv) {
 	char *namespace = "wlroots";
 	bool found;
 	int c;
-	while ((c = getopt(argc, argv, "w:h:o:"))) {
+	while ((c = getopt(argc, argv, "w:h:o:")) != -1) {
 		switch (c) {
 		case 'o':
 			output = atoi(optarg);
@@ -185,9 +185,6 @@ int main(int argc, char **argv) {
 		return 1;
 	}
 
-	wlr_egl_init(&egl, EGL_PLATFORM_WAYLAND_EXT, display, NULL,
-		WL_SHM_FORMAT_ARGB8888);
-
 	wl_surface = wl_compositor_create_surface(compositor);
 
 	struct zwlr_layer_surface_v1 *layer_surface =
@@ -195,8 +192,12 @@ int main(int argc, char **argv) {
 				wl_surface, wl_output, layer, namespace);
 	zwlr_layer_surface_v1_set_anchor(layer_surface, anchor);
 	// TODO: margin, interactivity, exclusive zone
-
 	wl_surface_commit(wl_surface);
+	wl_display_dispatch(display);
+	wl_display_roundtrip(display);
+
+	wlr_egl_init(&egl, EGL_PLATFORM_WAYLAND_EXT, display, NULL,
+		WL_SHM_FORMAT_ARGB8888);
 
 	egl_window = wl_egl_window_create(wl_surface, width, height);
 	egl_surface = wlr_egl_create_surface(&egl, egl_window);

rootston/desktop.c

@@ -719,6 +719,10 @@ struct roots_desktop *desktop_create(struct roots_server *server,
 	wl_signal_add(&desktop->layer_shell->events.new_surface,
 		&desktop->layer_shell_surface);
 	desktop->layer_shell_surface.notify = handle_layer_shell_surface;
+	for (size_t i = 0;
+			i < sizeof(desktop->layers) / sizeof(desktop->layers[0]); ++i) {
+		wl_list_init(&desktop->layers[i]);
+	}
 
 #ifdef WLR_HAS_XWAYLAND
 	const char *cursor_theme = NULL;

types/wlr_layer_shell.c

@@ -14,20 +14,20 @@ static void resource_handle_destroy(struct wl_client *client,
 	wl_resource_destroy(resource);
 }
 
-static struct zwlr_layer_shell_v1_interface layer_shell_impl;
+static const struct zwlr_layer_shell_v1_interface layer_shell_implementation;
-static struct zwlr_layer_surface_v1_interface layer_surface_impl;
+static const struct zwlr_layer_surface_v1_interface layer_surface_implementation;
 
 static struct wlr_layer_client *layer_client_from_resource(
 		struct wl_resource *resource) {
 	assert(wl_resource_instance_of(resource, &zwlr_layer_shell_v1_interface,
-		&layer_shell_impl));
+		&layer_shell_implementation));
 	return wl_resource_get_user_data(resource);
 }
 
 static struct wlr_layer_surface *layer_surface_from_resource(
 		struct wl_resource *resource) {
 	assert(wl_resource_instance_of(resource, &zwlr_layer_surface_v1_interface,
-		&layer_surface_impl));
+		&layer_surface_implementation));
 	return wl_resource_get_user_data(resource);
 }
 
@@ -291,11 +291,22 @@ static void layer_shell_handle_get_layer_surface(struct wl_client *wl_client,
 		wl_client_post_no_memory(wl_client);
 		return;
 	}
+	if (layer > ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY) {
+		wl_resource_post_error(surface->resource,
+				ZWLR_LAYER_SHELL_V1_ERROR_INVALID_LAYER,
+				"Invalid layer %d", layer);
+		free(surface);
+		return;
+	}
+
+	wl_list_init(&surface->configure_list);
 
 	wl_signal_init(&surface->events.destroy);
 	wl_signal_add(&surface->surface->events.destroy,
 		&surface->surface_destroy_listener);
 	surface->surface_destroy_listener.notify = handle_wlr_surface_destroyed;
+	wl_signal_init(&surface->events.map);
+	wl_signal_init(&surface->events.unmap);
 
 	wlr_surface_set_role_committed(surface->surface,
 		handle_wlr_surface_committed, surface);
@@ -307,7 +318,7 @@ static void layer_shell_handle_get_layer_surface(struct wl_client *wl_client,
 	wl_list_insert(&client->surfaces, &surface->link);
 }
 
-static struct zwlr_layer_shell_v1_interface layer_shell_impl = {
+static const struct zwlr_layer_shell_v1_interface layer_shell_implementation = {
 	.get_layer_surface = layer_shell_handle_get_layer_surface,
 };
 
@@ -347,8 +358,8 @@ static void layer_shell_bind(struct wl_client *wl_client, void *data,
 	client->client = wl_client;
 	client->shell = layer_shell;
 
-	wl_resource_set_implementation(client->resource, &layer_shell_impl, client,
+	wl_resource_set_implementation(client->resource,
-		wlr_layer_client_destroy);
+			&layer_shell_implementation, client, wlr_layer_client_destroy);
 	wl_list_insert(&layer_shell->clients, &client->link);
 }