Improve comments

lib/experimental/class-wp-rest-navigation-controller.php

@@ -46,6 +46,7 @@ public function get_fallbacks_permissions_check( $request ) {
 
 		$post_type = get_post_type_object( $this->post_type );
 
+		// Getting fallbacks also requires creating `wp_navigation` posts.
 		if ( ! current_user_can( $post_type->cap->create_posts ) ) {
 			return new WP_Error(
 				'rest_cannot_create',
@@ -54,15 +55,16 @@ public function get_fallbacks_permissions_check( $request ) {
 			);
 		}
 
-		return $this->check_has_read_only_access( $request );
+		// Gettting fallbacks requires reading `wp_navigation` posts.
+		return $this->check_has_read_only_access( $request, $post_type );
 	}
 
 	public function get_fallbacks() {
 		// Todo - see if we can inject this dependency.
 		return WP_Navigation_Gutenberg::get_fallback_menu();
 	}
 
-	protected function check_has_read_only_access( $request ) {
+	protected function check_has_read_only_access( $request, $post_type ) {
 		if ( current_user_can( 'edit_theme_options' ) ) {
 			return true;
 		}
@@ -71,8 +73,6 @@ protected function check_has_read_only_access( $request ) {
 			return true;
 		}
 
-		$post_type = get_post_type_object( $this->post_type );
-
 		if ( 'edit' === $request['context'] && ! current_user_can( $post_type->cap->edit_posts ) ) {
 			return new WP_Error(
 				'rest_forbidden_context',