bug #385 update to smarty-3.1.28-dev (from Github)

include/smarty/libs/sysplugins/smarty_undefined_variable.php

@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * class for undefined variable object
+ * This class defines an object for undefined variable handling
+ *
+ * @package    Smarty
+ * @subpackage Template
+ */
+class Smarty_Undefined_Variable
+{
+    /**
+     * Returns FALSE for 'nocache' and NULL otherwise.
+     *
+     * @param  string $name
+     *
+     * @return bool
+     */
+    public function __get($name)
+    {
+        if ($name == 'nocache') {
+            return false;
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Always returns an empty string.
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return "";
+    }
+}