diff --git a/library/smarty/libs/sysplugins/smarty_internal_parsetree_dq.php b/library/smarty/libs/sysplugins/smarty_internal_parsetree_dq.php
new file mode 100644
--- /dev/null
+++ b/library/smarty/libs/sysplugins/smarty_internal_parsetree_dq.php
@@ -0,0 +1,82 @@
+<?php
+
+/**
+ * Double quoted string inside a tag.
+ *
+ * @package    Smarty
+ * @subpackage Compiler
+ * @ignore
+ */
+
+/**
+ * Double quoted string inside a tag.
+ *
+ * @package    Smarty
+ * @subpackage Compiler
+ * @ignore
+ */
+class Smarty_Internal_ParseTree_Dq extends Smarty_Internal_ParseTree {
+    /**
+     * Create parse tree buffer for double quoted string subtrees
+     *
+     * @param object $parser parser object
+     * @param Smarty_Internal_ParseTree $subtree parse tree buffer
+     */
+    public function __construct($parser, Smarty_Internal_ParseTree $subtree) {
+        $this->parser = $parser;
+        $this->subtrees[] = $subtree;
+        if ($subtree instanceof Smarty_Internal_ParseTree_Tag) {
+            $this->parser->block_nesting_level = count($this->parser->compiler->_tag_stack);
+        }
+    }
+
+    /**
+     * Append buffer to subtree
+     *
+     * @param Smarty_Internal_ParseTree $subtree parse tree buffer
+     */
+    public function append_subtree(Smarty_Internal_ParseTree $subtree) {
+        $last_subtree = count($this->subtrees) - 1;
+        if ($last_subtree >= 0 && $this->subtrees[$last_subtree] instanceof Smarty_Internal_ParseTree_Tag && $this->subtrees[$last_subtree]->saved_block_nesting < $this->parser->block_nesting_level) {
+            if ($subtree instanceof Smarty_Internal_ParseTree_Code) {
+                $this->subtrees[$last_subtree]->data = $this->parser->compiler->appendCode($this->subtrees[$last_subtree]->data, '<?php echo ' . $subtree->data . ';?>');
+            } elseif ($subtree instanceof Smarty_Internal_ParseTree_DqContent) {
+                $this->subtrees[$last_subtree]->data = $this->parser->compiler->appendCode($this->subtrees[$last_subtree]->data, '<?php echo "' . $subtree->data . '";?>');
+            } else {
+                $this->subtrees[$last_subtree]->data = $this->parser->compiler->appendCode($this->subtrees[$last_subtree]->data, $subtree->data);
+            }
+        } else {
+            $this->subtrees[] = $subtree;
+        }
+        if ($subtree instanceof Smarty_Internal_ParseTree_Tag) {
+            $this->parser->block_nesting_level = count($this->parser->compiler->_tag_stack);
+        }
+    }
+
+    /**
+     * Merge subtree buffer content together
+     *
+     * @return string compiled template code
+     */
+    public function to_smarty_php() {
+        $code = '';
+        foreach ($this->subtrees as $subtree) {
+            if ($code !== "") {
+                $code .= ".";
+            }
+            if ($subtree instanceof Smarty_Internal_ParseTree_Tag) {
+                $more_php = $subtree->assign_to_var();
+            } else {
+                $more_php = $subtree->to_smarty_php();
+            }
+
+            $code .= $more_php;
+
+            if (!$subtree instanceof Smarty_Internal_ParseTree_DqContent) {
+                $this->parser->compiler->has_variable_string = true;
+            }
+        }
+
+        return $code;
+    }
+}