View difference between Paste ID: C3VTuqrV and nh6sRsjx

 function pm_detect_old_slugs() {
 	global $wp_query, $wp, $wpdb;
 
 	// Stop if any post or term was already found by Permalink Manager
 	if(!empty($wp_query->query['do_not_redirect']) || !empty($wp_query->query_vars['do_not_redirect']) || (!is_404())) {
 		return;
 	}
 
 	// Get all the endpoints & pattern
-	preg_match('/([^\/]+)(?:\/([\d]+))?/', $wp->request, $parts);
+	if(class_exists('Permalink_Manager_Helper_Functions')) {
 		$endpoints = Permalink_Manager_Helper_Functions::get_endpoints();
-		$post_id = $wpdb->get_var($wpdb->prepare("SELECT post_id from {$wpdb->postmeta} WHERE meta_key = '_wp_old_slug' AND meta_value LIKE '%%%s%%'", $parts[1]));
+		$pattern = "/^(.+?)(?|\/({$endpoints})(?|\/(.*)|$)|\/()([\d]+)\/?)?$/i";
 	} else {
-		// Redirect if post with old slug was found
+		$pattern = '/([^\/]+)?(?:\/([\d]+))?/';
 	}
 
-			$permalink = (!empty($parts[2])) ? sprintf('%s/%d', trim($permalink, '/'), $parts[2]) : '';
+
 	preg_match($pattern, $wp->request, $parts);
 	if(!empty($parts[1])) {
 		$slug = basename($parts[1]);
 		$post_id = $wpdb->get_var($wpdb->prepare("SELECT post_id from {$wpdb->postmeta} WHERE meta_key = '_wp_old_slug' AND meta_value LIKE '%%%s%%'", $slug));
 
 		// Parse the endpoints
 		$endpoint = (!empty($parts[2])) ? $parts[2] : '';
 		$endpoint_value = (!empty($parts[3])) ? $parts[3] : '';
 
 		// Redirect if any post with old slug was found
 		if(!empty($post_id)) {
 			$permalink = get_permalink($post_id);
 
 			if(!empty($endpoint_value) || !empty($endpoint)) {
 				if(empty($endpoint) && is_numeric($endpoint_value)) {
 					$permalink = sprintf("%s/%d", trim($permalink, "/"), $endpoint_value);
 				} else if(isset($endpoint) && !empty($endpoint_value)) {
 					$permalink = sprintf("%s/%s/%s", trim($permalink, "/"), $endpoint, $endpoint_value);
 				} else {
 					$permalink = sprintf("%s/%s", trim($permalink, "/"), $endpoint);
 				}
 			}
 
 			wp_safe_redirect($permalink, 301);
 			exit();
 		}
 	}
 }
 add_action('template_redirect', 'pm_detect_old_slugs', 0);