[gxml] BackedNode.vala: actually implement clone_node, add a TODO

[Richard Hans Schwarting <rschwart src gnome org>]

commit aa64ffdfb028c9d01810d3b68ced8692d84bd145
Author: Richard Schwarting <aquarichy gmail com>
Date:   Wed Aug 21 15:22:35 2013 -0400

    BackedNode.vala: actually implement clone_node, add a TODO

 gxml/BackedNode.vala |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gxml/BackedNode.vala b/gxml/BackedNode.vala
index 2019dfd..eb75926 100644
--- a/gxml/BackedNode.vala
+++ b/gxml/BackedNode.vala
@@ -291,7 +291,8 @@ namespace GXml {
                 * { inheritDoc}
                 */
                public override Node? clone_node (bool deep) {
-                       return this; // STUB
+                       return this.owner_document.copy_node (this, deep);
+                       // TODO: add a better test, as we weren't realising this was just a stub; test for 
memory usage too
                }
 
                public override string to_string (bool format = false, int level = 0) {