Issue #3312595 by awasson, Chase., DamienMcKenna, Anybody: strlen(): Passing...

Issue #3312595 by awasson, Chase., DamienMcKenna, Anybody: strlen(): Passing null to parameter #1 ($string) of type string is deprecated.

includes/handlers.inc

@@ -328,7 +328,7 @@ class views_handler extends views_object {
    *   Returns the safe value.
    */
   public function sanitize_value($value, $type = NULL) {
-    if (strlen($value) > 0) {
+    if (!is_null($value) && strlen($value) > 0) {
       switch ($type) {
         case 'xss':
           $value = filter_xss($value);