[gxml] Fixed NS for document_element with no-prefix

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit f5a6366aa88697e21d06f25abe17d33878dec19e
Author: Daniel Espinosa <esodan gmail com>
Date:   Mon Jan 23 14:36:05 2017 -0600

    Fixed NS for document_element with no-prefix

 gxml/XParser.vala         |   17 +++++++++++++----
 test/GomDocumentTest.vala |    7 +++----
 2 files changed, 16 insertions(+), 8 deletions(-)
---
diff --git a/gxml/XParser.vala b/gxml/XParser.vala
index 7656c1c..cdddf5a 100644
--- a/gxml/XParser.vala
+++ b/gxml/XParser.vala
@@ -597,11 +597,20 @@ public class GXml.XParser : Object, GXml.Parser {
 #endif
       if ((node as DomElement).namespace_uri != null) {
 #if DEBUG
-            GLib.message ("Writting namespace definition for node");
+          GLib.message ("Writting namespace definition for node");
 #endif
-          tw.start_element_ns ((node as DomElement).prefix,
-                               (node as DomElement).local_name,
-                               (node as DomElement).namespace_uri);
+          string lpns = (node.parent_node).lookup_prefix ((node as DomElement).namespace_uri);
+          if (lpns == (node as DomElement).prefix
+              && (node as DomElement).prefix != null) {
+            tw.start_element (node.node_name);
+#if DEBUG
+            message ("Setting null NS URI for element: "+(node as DomElement).local_name);
+#endif
+          }
+          else
+            tw.start_element_ns ((node as DomElement).prefix,
+                                 (node as DomElement).local_name,
+                                 (node as DomElement).namespace_uri);
       } else
         tw.start_element ((node as DomElement).local_name);
 #if DEBUG
diff --git a/test/GomDocumentTest.vala b/test/GomDocumentTest.vala
index 2a2ac8d..64b429a 100644
--- a/test/GomDocumentTest.vala
+++ b/test/GomDocumentTest.vala
@@ -167,9 +167,8 @@ class GomDocumentTest : GXmlTest {
                                assert ("<shortdesc xml:lang=\"en\">GObject XML and Serialization 
API</shortdesc>"
                                                                in s);
                                assert ("<homepage rdf:resource=\"https://wiki.gnome.org/GXml\"/>" in s);
-                               assert ("<foaf:Person" in s);
-                               assert ("<foaf:name " in s);
-                               assert ("Daniel Espinosa</foaf:name>"in s);
+                               assert ("<foaf:Person>" in s);
+                               assert ("<foaf:name>Daniel Espinosa</foaf:name>" in s);
                        } catch (GLib.Error e) {
                                GLib.message ("Error: "+e.message);
                                assert_not_reached ();
@@ -184,7 +183,7 @@ class GomDocumentTest : GXmlTest {
                                assert (r.namespace_uri == "http://live.gnome.org/GXml";);
                                var parser = new XParser (doc);
                                string s = parser.write_string ();
-                               GLib.message (@"DOC: "+s);
+                               Test.message (@"DOC: "+s);
                                assert ("<root xmlns=\"http://live.gnome.org/GXml\"/>" in s);
                                doc.document_element.set_attribute_ns ("http://www.w3.org/2000/xmlns/";,
                                                                                                              
                                                                          "xmlns",