Ticket #39102: 39102.0.diff

src/wp-includes/js/customize-preview-nav-menus.js

@@ -419 +419 @@
                                 return;
                         }
 
-                        navMenuItemParts = $( this ).attr( 'class' ).match( /(?:^|\s)menu-item-(\d+)(?:\s|$)/ );
+                        navMenuItemParts = $( this ).attr( 'class' ).match( /(?:^|\s)menu-item-(-?\d+)(?:\s|$)/ );
                         if ( navMenuItemParts ) {
                                 e.preventDefault();
                                 e.stopPropagation(); // Make sure a sub-nav menu item will get focused instead of parent items.