Re-introduce check to prevent unintentional "all active" return for not yet selected results list elements

Author: Brian Feister

src/select.js

@@ -304,6 +304,9 @@
     };
 
     ctrl.isActive = function(itemScope) {
+      if ( typeof itemScope[ctrl.itemProperty] === 'undefined') {
+        return false;
+      }
       return ctrl.open && ctrl.items.indexOf(itemScope[ctrl.itemProperty]) === ctrl.activeIndex;
     };