Ticket #39564: 39564.2.patch

src/wp-includes/class-walker-page.php

@@ -53 +53 @@
          *                       Default empty array.
          */
         public function start_lvl( &$output, $depth = 0, $args = array() ) {
-                if ( 'preserve' === $args['item_spacing'] ) {
+                if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
                         $t = "\t";
                         $n = "\n";
                 } else {
@@ -78 +78 @@
          *                       Default empty array.
          */
         public function end_lvl( &$output, $depth = 0, $args = array() ) {
-                if ( 'preserve' === $args['item_spacing'] ) {
+                if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
                         $t = "\t";
                         $n = "\n";
                 } else {
@@ -103 +103 @@
          * @param int     $current_page Optional. Page ID. Default 0.
          */
         public function start_el( &$output, $page, $depth = 0, $args = array(), $current_page = 0 ) {
-                if ( 'preserve' === $args['item_spacing'] ) {
+                if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
                         $t = "\t";
                         $n = "\n";
                 } else {
@@ -196 +196 @@
          * @param array   $args   Optional. Array of arguments. Default empty array.
          */
         public function end_el( &$output, $page, $depth = 0, $args = array() ) {
-                if ( 'preserve' === $args['item_spacing'] ) {
+                if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
                         $t = "\t";
                         $n = "\n";
                 } else {