fix setItems keeping references to original arrays.

lib/widget.js

@@ -4221,10 +4221,11 @@ List.prototype.removeItem = function(child) {
 };
 
 List.prototype.setItems = function(items) {
-  var i = 0
+  var items = items.slice()
     , original = this.items.slice()
     , selected = this.selected
-    , sel = this.ritems[this.selected];
+    , sel = this.ritems[this.selected]
+    , i = 0;
 
   this.select(0);