diff -r be944660c56a -r 3d72ae0968f4 wp/wp-includes/sitemaps/class-wp-sitemaps-provider.php
--- a/wp/wp-includes/sitemaps/class-wp-sitemaps-provider.php	Wed Sep 21 18:19:35 2022 +0200
+++ b/wp/wp-includes/sitemaps/class-wp-sitemaps-provider.php	Tue Sep 27 16:37:53 2022 +0200
@@ -42,7 +42,7 @@
 	 *
 	 * @param int    $page_num       Page of results.
 	 * @param string $object_subtype Optional. Object subtype name. Default empty.
-	 * @return array Array of URLs for a sitemap.
+	 * @return array[] Array of URL information for a sitemap.
 	 */
 	abstract public function get_url_list( $page_num, $object_subtype = '' );
 
@@ -160,7 +160,7 @@
 		);
 
 		if ( ! $wp_rewrite->using_permalinks() ) {
-			$basename = '/?' . http_build_query( $params, null, '&' );
+			$basename = '/?' . http_build_query( $params, '', '&' );
 		}
 
 		return home_url( $basename );