Ticket #37344: 37344-2.patch

src/wp-includes/class-walker-nav-menu.php

@@ -116 +116 @@
          * @param int      $id     Current item ID.
          */
         public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
+                $args = (array) $args; // cast to array prevents object-by-reference side effects
                 if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {
                         $t = '';
                         $n = '';
@@ -137 +138 @@
                  * @param WP_Post  $item  Menu item data object.
                  * @param int      $depth Depth of menu item. Used for padding.
                  */
-                $args = apply_filters( 'nav_menu_item_args', $args, $item, $depth );
+                $args = apply_filters( 'nav_menu_item_args', (object) $args, $item, $depth );
 
                 /**
                  * Filters the CSS classes applied to a menu item's list item element.