Ticket #30722: 30722.1.diff

src/wp-content/themes/twentyfifteen/js/functions.js

@@ -13 +13 @@
         // Add dropdown toggle that display child menu items.
         $( '.main-navigation .page_item_has_children > a, .main-navigation .menu-item-has-children > a' ).after( '<button class="dropdown-toggle" aria-expanded="false">' + screenReaderText.expand + '</button>' );
 
+        // Toggle buttons and submenu items with active children menu items
+        $( '.main-navigation .current-menu-ancestor > button' ).addClass( 'toggle-on' );
+        $( '.main-navigation .current-menu-ancestor > .sub-menu' ).addClass( 'toggled-on' );
+
         $( '.dropdown-toggle' ).click( function( e ) {
                 var _this = $( this );
                 e.preventDefault();

src/wp-content/themes/twentyfifteen/style.css

@@ -682 +682 @@
 
 .main-navigation .current_page_item > a,
 .main-navigation .current-menu-item > a,
+.main-navigation .current-menu-ancestor > a,
 .main-navigation .current_page_ancestor > a {
         font-weight: 700;
 }