smarty 3.1.39 upgrade

include/smarty/libs/sysplugins/smarty_undefined_variable.php

@@ -7,22 +7,18 @@
  * @package    Smarty
  * @subpackage Template
  */
-class Smarty_Undefined_Variable
+class Smarty_Undefined_Variable extends Smarty_Variable
 {
     /**
-     * Returns FALSE for 'nocache' and NULL otherwise.
+     * Returns null for not existing properties
      *
-     * @param  string $name
+     * @param string $name
      *
-     * @return bool
+     * @return null
      */
     public function __get($name)
     {
-        if ($name == 'nocache') {
-            return false;
-        } else {
-            return null;
-        }
+        return null;
     }
 
     /**
@@ -32,6 +28,6 @@ class Smarty_Undefined_Variable
      */
     public function __toString()
     {
-        return "";
+        return '';
     }
 }