_parent_item_ids[]   = (int) $menu_item->menu_item_parent;
			$active_parent_object_ids[] = (int) $menu_item->post_parent;
			$active_object              = $menu_item->object;

			// If the menu item corresponds to the currently queried post type archive.
		} elseif (
			'post_type_archive' === $menu_item->type
			&& is_post_type_archive( array( $menu_item->object ) )
		) {
			$classes[]                   = 'current-menu-item';
			$menu_items[ $key ]->current = true;
			$_anc_id                     = (int) $menu_item->db_id;

			while (
				( $_anc_id = (int) get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) )
				&& ! in_array( $_anc_id, $active_ancestor_item_ids, true )
			) {
				$active_ancestor_item_ids[] = $_anc_id;
			}

			$active_parent_item_ids[] = (int) $menu_item->menu_item_parent;

			// If the menu item corresponds to the currently requested URL.
		} elseif ( 'custom' === $menu_item->object && isset( $_SERVER['HTTP_HOST'] ) ) {
			$_root_relative_current = untrailingslashit( $_SERVER['REQUEST_URI'] );

			// If it's the customize page then it will strip the query var off the URL before entering the comparison block.
			if ( is_customize_preview() ) {
				$_root_relative_current = strtok( untrailingslashit( $_SERVER['REQUEST_URI'] ), '?' );
			}

			$current_url        = set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_root_relative_current );
			$raw_item_url       = strpos( $menu_item->url, '#' ) ? substr( $menu_item->url, 0, strpos( $menu_item->url, '#' ) ) : $menu_item->url;
			$item_url           = set_url_scheme( untrailingslashit( $raw_item_url ) );
			$_indexless_current = untrailingslashit( preg_replace( '/' . preg_quote( $wp_rewrite->index, '/' ) . '$/', '', $current_url ) );

			$matches = array(
				$current_url,
				urldecode( $current_url ),
				$_indexless_current,
				urldecode( $_indexless_current ),
				$_root_relative_current,
				urldecode( $_root_relative_current ),
			);

			if ( $raw_item_url && in_array( $item_url, $matches, true ) ) {
				$classes[]                   = 'current-menu-item';
				$menu_items[ $key ]->current = true;
				$_anc_id                     = (int) $menu_item->db_id;

				while (
					( $_anc_id = (int) get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) )
					&& ! in_array( $_anc_id, $active_ancestor_item_ids, true )
				) {
					$active_ancestor_item_ids[] = $_anc_id;
				}

				if ( in_array( home_url(), array( untrailingslashit( $current_url ), untrailingslashit( $_indexless_current ) ), true ) ) {
					// Back compat for home link to match wp_page_menu().
					$classes[] = 'current_page_item';
				}
				$active_parent_item_ids[]   = (int) $menu_item->menu_item_parent;
				$active_parent_object_ids[] = (int) $menu_item->post_parent;
				$active_object              = $menu_item->object;

				// Give front page item the 'current-menu-item' class when extra query arguments are involved.
			} elseif ( $item_url == $front_page_url && is_front_page() ) {
				$classes[] = 'current-menu-item';
			}

			if ( untrailingslashit( $item_url ) == home_url() ) {
				$classes[] = 'menu-item-home';
			}
		}

		// Back-compat with wp_page_menu(): add "current_page_parent" to static home page link for any non-page query.
		if ( ! empty( $home_page_id ) && 'post_type' === $menu_item->type
			&& empty( $wp_query->is_page ) && $home_page_id == $menu_item->object_id
		) {
			$classes[] = 'current_page_parent';
		}

		$menu_items[ $key ]->classes = array_unique( $classes );
	}
	$active_ancestor_item_ids = array_filter( array_unique( $active_ancestor_item_ids ) );
	$active_parent_item_ids   = array_filter( array_unique( $active_parent_item_ids ) );
	$active_parent_object_ids = array_filter( array_unique( $active_parent_object_ids ) );

	// Set parent's class.
	foreach ( (array) $menu_items as $key => $parent_item ) {
		$classes                                   = (array) $parent_item->classes;
		$menu_items[ $key ]->current_item_ancestor = false;
		$menu_items[ $key ]->current_item_parent   = false;

		if (
			isset( $parent_item->type )
			&& (
				// Ancestral post object.
				(
					'post_type' === $parent_item->type
					&& ! empty( $queried_object->post_type )
					&& is_post_type_hierarchical( $queried_object->post_type )
					&& in_array( (int) $parent_item->object_id, $queried_object->ancestors, true )
					&& $parent_item->object != $queried_object->ID
				) ||

				// Ancestral term.
				(
					'taxonomy' === $parent_item->type
					&& isset( $possible_taxonomy_ancestors[ $parent_item->object ] )
					&& in_array( (int) $parent_item->object_id, $possible_taxonomy_ancestors[ $parent_item->object ], true )
					&& (
						! isset( $queried_object->term_id ) ||
						$parent_item->object_id != $queried_object->term_id
					)
				)
			)
		) {
			if ( ! empty( $queried_object->taxonomy ) ) {
				$classes[] = 'current-' . $queried_object->taxonomy . '-ancestor';
			} else {
				$classes[] = 'current-' . $queried_object->post_type . '-ancestor';
			}
		}

		if ( in_array( (int) $parent_item->db_id, $active_ancestor_item_ids, true ) ) {
			$classes[] = 'current-menu-ancestor';

			$menu_items[ $key ]->current_item_ancestor = true;
		}
		if ( in_array( (int) $parent_item->db_id, $active_parent_item_ids, true ) ) {
			$classes[] = 'current-menu-parent';

			$menu_items[ $key ]->current_item_parent = true;
		}
		if ( in_array( (int) $parent_item->object_id, $active_parent_object_ids, true ) ) {
			$classes[] = 'current-' . $active_object . '-parent';
		}

		if ( 'post_type' === $parent_item->type && 'page' === $parent_item->object ) {
			// Back compat classes for pages to match wp_page_menu().
			if ( in_array( 'current-menu-parent', $classes, true ) ) {
				$classes[] = 'current_page_parent';
			}
			if ( in_array( 'current-menu-ancestor', $classes, true ) ) {
				$classes[] = 'current_page_ancestor';
			}
		}

		$menu_items[ $key ]->classes = array_unique( $classes );
	}
}

/**
 * Retrieves the HTML list content for nav menu items.
 *
 * @uses Walker_Nav_Menu to create HTML list content.
 * @since 3.0.0
 *
 * @param array    $items The menu items, sorted by each menu item's menu order.
 * @param int      $depth Depth of the item in reference to parents.
 * @param stdClass $r     An object containing wp_nav_menu() arguments.
 * @return string The HTML list content for the menu items.
 */
function walk_nav_menu_tree( $items, $depth, $r ) {
	$walker = ( empty( $r->walker ) ) ? new Walker_Nav_Menu : $r->walker;

	return $walker->walk( $items, $depth, $r );
}

/**
 * Prevents a menu item ID from being used more than once.
 *
 * @since 3.0.1
 * @access private
 *
 * @param string $id
 * @param object $item
 * @return string
 */
function _nav_menu_item_id_use_once( $id, $item ) {
	static $_used_ids = array();

	if ( in_array( $item->ID, $_used_ids, true ) ) {
		return '';
	}

	$_used_ids[] = $item->ID;

	return $id;
}