Fix dropdown opener having empty string for href value.

Fixes: #345

Author: pattonwebz

CHANGELOG.md

@@ -1,4 +1,6 @@
 #CHANGELOG
+## [4.0.2]
+- Fix dropdown opener having empty string for href value.
 
 ## [4.0.1]
 - Fix untranslated string in fallback (this was lost in transition between v3 and v4, fixed again).

class-wp-bootstrap-navwalker.php

@@ -11,7 +11,7 @@
  * Plugin URI:  https://github.com/wp-bootstrap/wp-bootstrap-navwalker
  * Description: A custom WordPress nav walker class to implement the Bootstrap 4 navigation style in a custom theme using the WordPress built in menu manager.
  * Author: Edward McIntyre - @twittem, WP Bootstrap, William Patton - @pattonwebz
- * Version: 4.0.1
+ * Version: 4.0.2-dev
  * Author URI: https://github.com/wp-bootstrap
  * GitHub Plugin URI: https://github.com/wp-bootstrap/wp-bootstrap-navwalker
  * GitHub Branch: master
@@ -189,7 +189,7 @@ public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0
 				$atts['class']         = 'dropdown-toggle nav-link';
 				$atts['id']            = 'menu-item-dropdown-' . $item->ID;
 			} else {
-				$atts['href'] = ! empty( $item->url ) ? $item->url : '';
+				$atts['href'] = ! empty( $item->url ) ? $item->url : '#';
 				// Items in dropdowns use .dropdown-item instead of .nav-link.
 				if ( $depth > 0 ) {
 					$atts['class'] = 'dropdown-item';