--- a/wp/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php	Wed Sep 21 18:19:35 2022 +0200
+++ b/wp/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php	Tue Sep 27 16:37:53 2022 +0200
@@ -49,10 +49,10 @@
 	 */
 	public function __construct( $parent_post_type ) {
 		$this->parent_post_type  = $parent_post_type;
-		$this->namespace         = 'wp/v2';
 		$this->rest_base         = 'revisions';
 		$post_type_object        = get_post_type_object( $parent_post_type );
 		$this->parent_base       = ! empty( $post_type_object->rest_base ) ? $post_type_object->rest_base : $post_type_object->name;
+		$this->namespace         = ! empty( $post_type_object->rest_namespace ) ? $post_type_object->rest_namespace : 'wp/v2';
 		$this->parent_controller = $post_type_object->get_rest_controller();
 
 		if ( ! $this->parent_controller ) {
@@ -535,12 +535,15 @@
 	 * Prepares the revision for the REST response.
 	 *
 	 * @since 4.7.0
+	 * @since 5.9.0 Renamed `$post` to `$item` to match parent class for PHP 8 named parameter support.
 	 *
-	 * @param WP_Post         $post    Post revision object.
+	 * @param WP_Post         $item    Post revision object.
 	 * @param WP_REST_Request $request Request object.
 	 * @return WP_REST_Response Response object.
 	 */
-	public function prepare_item_for_response( $post, $request ) {
+	public function prepare_item_for_response( $item, $request ) {
+		// Restores the more descriptive, specific name for use within this method.
+		$post            = $item;
 		$GLOBALS['post'] = $post;
 
 		setup_postdata( $post );