diff --git a/library/smarty/libs/sysplugins/smarty_internal_parsetree.php b/library/smarty/libs/sysplugins/smarty_internal_parsetree.php
new file mode 100644
--- /dev/null
+++ b/library/smarty/libs/sysplugins/smarty_internal_parsetree.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * Smarty Internal Plugin Templateparser Parsetrees
+ * These are classes to build parsetrees in the template parser
+ *
+ * @package    Smarty
+ * @subpackage Compiler
+ * @author     Thue Kristensen
+ * @author     Uwe Tews
+ */
+
+/**
+ * @package    Smarty
+ * @subpackage Compiler
+ * @ignore
+ */
+abstract class Smarty_Internal_ParseTree {
+
+    /**
+     * Parser object
+     *
+     * @var object
+     */
+    public $parser;
+
+    /**
+     * Buffer content
+     *
+     * @var mixed
+     */
+    public $data;
+
+    /**
+     * Subtree array
+     *
+     * @var array
+     */
+    public $subtrees = array();
+
+    /**
+     * Return buffer
+     *
+     * @return string buffer content
+     */
+    abstract public function to_smarty_php();
+}
+
+