From ab9c9a3c78f93b0e2db4c795835f1279b11a87d3 Mon Sep 17 00:00:00 2001
From: "Thomas A. Reinert" <symbian60.mobi@gmail.com>
Date: Tue, 4 Jun 2019 12:55:00 +0200
Subject: [PATCH] Fixes #973

---
 inc/class-wp-bootstrap-navwalker.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/inc/class-wp-bootstrap-navwalker.php b/inc/class-wp-bootstrap-navwalker.php
index 5dd2331..7deeca2 100644
--- a/inc/class-wp-bootstrap-navwalker.php
+++ b/inc/class-wp-bootstrap-navwalker.php
@@ -183,7 +183,12 @@ if ( ! class_exists( 'Understrap_WP_Bootstrap_Navwalker' ) ) {
 			}
 
 			$atts['target'] = ! empty( $item->target ) ? $item->target : '';
-			$atts['rel']    = ! empty( $item->xfn ) ? $item->xfn : '';
+			if ( '_blank' === $item->target && empty( $item->xfn ) ) { // Thanks to LukaszJaro, see https://github.com/understrap/understrap/issues/973
+				$atts['rel'] = 'noopener noreferrer';
+			} else {
+				$atts['rel'] = $item->xfn;
+			}
+
 			// If item has_children add atts to <a>.
 			if ( isset( $args->has_children ) && $args->has_children && 0 === $depth && $args->depth !== 1 ) {
 				$atts['href']          = '#';