[gxml] GomCollection: Fixed get_item() with unit tests

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit faf265f4ca3aa65ba12b63601398c79b01f56329
Author: Daniel Espinosa <esodan gmail com>
Date:   Sun Nov 6 11:49:13 2016 -0600

    GomCollection: Fixed get_item() with unit tests

 gxml/GomCollections.vala       |    4 +++-
 test/GomSerializationTest.vala |   12 +++++++++---
 2 files changed, 12 insertions(+), 4 deletions(-)
---
diff --git a/gxml/GomCollections.vala b/gxml/GomCollections.vala
index ce73487..256e927 100644
--- a/gxml/GomCollections.vala
+++ b/gxml/GomCollections.vala
@@ -52,7 +52,9 @@ public interface GXml.GomCollection : Object
    * {@link nodes_index}.
    */
   public virtual DomElement? get_item (int index) throws GLib.Error {
-    var e = element.child_nodes.get (index);
+    unowned List<int> i = nodes_index.nth (index);
+    if (i == null) return null;
+    var e = element.child_nodes.get (i.data);
     if (e != null)
       if (!(e is GomElement))
         throw new DomError.INVALID_NODE_TYPE_ERROR
diff --git a/test/GomSerializationTest.vala b/test/GomSerializationTest.vala
index 238a1d7..94892ae 100644
--- a/test/GomSerializationTest.vala
+++ b/test/GomSerializationTest.vala
@@ -154,7 +154,6 @@ class GomSerializationTest : GXmlTest  {
       assert ("<BookStand Classification=\"Science\"/>" in s);
       assert (bs.registers == null);
       var br = new BookRegister ();
-      br.year = 2016;
       bs.registers = new GomArrayList.initialize (bs,br.local_name);
       s = bs.to_string ();
       assert (s != null);
@@ -162,19 +161,26 @@ class GomSerializationTest : GXmlTest  {
       assert ("<BookStand Classification=\"Science\"/>" in s);
       try { bs.registers.add (br); } catch {}
       br = new BookRegister.document (bs.owner_document);
+      br.year = 2016;
       bs.registers.add (br);
       s = bs.to_string ();
       assert (s != null);
       GLib.message ("DOC:"+s);
-      assert ("<BookStand Classification=\"Science\"><BookRegister Year=\"0\"/></BookStand>" in s);
+      assert ("<BookStand Classification=\"Science\"><BookRegister Year=\"2016\"/></BookStand>" in s);
       var br2 = new BookRegister.document (bs.owner_document);
       bs.registers.add (br2);
+      br2.year = 2010;
+      bs.append_child (bs.owner_document.create_element ("Test"));
       var br3 = new BookRegister.document (bs.owner_document);
       bs.registers.add (br3);
+      br3.year = 2000;
       s = bs.to_string ();
       assert (s != null);
       GLib.message ("DOC:"+s);
-      assert ("<BookStand Classification=\"Science\"><BookRegister Year=\"0\"/><BookRegister 
Year=\"0\"/><BookRegister Year=\"0\"/></BookStand>" in s);
+      assert ("<BookStand Classification=\"Science\"><BookRegister Year=\"2016\"/><BookRegister 
Year=\"2010\"/><Test/><BookRegister Year=\"2000\"/></BookStand>" in s);
+      assert ((bs.registers.get_item (0) as BookRegister).year == 2016);
+      assert ((bs.registers.get_item (1) as BookRegister).year == 2010);
+      assert ((bs.registers.get_item (2) as BookRegister).year == 2000);
     });
     Test.add_func ("/gxml/gom-serialization/read/properties", () => {
       var b = new Book ();