From a882a65ab1e3210bc590565284a7c7da9f57dbc1 Mon Sep 17 00:00:00 2001
From: Atsushi Eno <atsushieno@veritas-vos-liberabit.com>
Date: Thu, 7 Jun 2012 12:57:31 +0900
Subject: [PATCH] Use non-prefixed namespace output for element when
 applicable. Fixed bug #5519.

---
 mcs/class/System.Xml.Linq/System.Xml.Linq/XElement.cs          | 10 ++++++----
 mcs/class/System.Xml.Linq/Test/System.Xml.Linq/XElementTest.cs |  8 ++++++++
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/mcs/class/System.Xml.Linq/System.Xml.Linq/XElement.cs b/mcs/class/System.Xml.Linq/System.Xml.Linq/XElement.cs
index eb379a1d503..3586a086a88 100644
--- a/mcs/class/System.Xml.Linq/System.Xml.Linq/XElement.cs
+++ b/mcs/class/System.Xml.Linq/System.Xml.Linq/XElement.cs
@@ -667,13 +667,15 @@ namespace System.Xml.Linq
 			return prefix;
 		}
 		
-		static string CreateDummyNamespace (ref int createdNS, IEnumerable<XAttribute> atts)
+		static string CreateDummyNamespace (ref int createdNS, IEnumerable<XAttribute> atts, bool isAttr)
 		{
+			if (!isAttr && atts.All (a => a.Name.LocalName != "xmlns" || a.Name.NamespaceName == XNamespace.Xmlns.NamespaceName))
+				return String.Empty;
 			string p = null;
 			do {
 				p = "p" + (++createdNS);
 				// check conflict
-				if (atts.All (a => a.Name.LocalName != p))
+				if (atts.All (a => a.Name.LocalName != p || a.Name.NamespaceName == XNamespace.Xmlns.NamespaceName))
 					break;
 			} while (true);
 			return p;
@@ -686,7 +688,7 @@ namespace System.Xml.Linq
 			string prefix = LookupPrefix (name.NamespaceName, w);
 			int createdNS = 0;
 			if (prefix == null)
-				prefix = CreateDummyNamespace (ref createdNS, Attributes ());
+				prefix = CreateDummyNamespace (ref createdNS, Attributes (), false);
 
 			w.WriteStartElement (prefix, name.LocalName, name.Namespace.NamespaceName);
 
@@ -699,7 +701,7 @@ namespace System.Xml.Linq
 				} else {
 					string apfix = LookupPrefix (a.Name.NamespaceName, w);
 					if (apfix == null)
-						apfix = CreateDummyNamespace (ref createdNS, Attributes ());
+						apfix = CreateDummyNamespace (ref createdNS, Attributes (), true);
 					w.WriteAttributeString (apfix, a.Name.LocalName, a.Name.Namespace.NamespaceName, a.Value);
 				}
 			}
diff --git a/mcs/class/System.Xml.Linq/Test/System.Xml.Linq/XElementTest.cs b/mcs/class/System.Xml.Linq/Test/System.Xml.Linq/XElementTest.cs
index 3a89e1299e3..3a21ee24718 100644
--- a/mcs/class/System.Xml.Linq/Test/System.Xml.Linq/XElementTest.cs
+++ b/mcs/class/System.Xml.Linq/Test/System.Xml.Linq/XElementTest.cs
@@ -1722,5 +1722,13 @@ namespace MonoTests.System.Xml.Linq
 			string expected = @"<xsi:eventData xsi1:type='xsi:CallSubscriptionEvent' xmlns:xsi1='http://www.w3.org/2001/XMLSchema-instance' xmlns:xsi='http://relevo.se/xsi' />".Replace ('\'', '"');
 			Assert.AreEqual (expected, e.Nodes ().First ().ToString (), "#1");
 		}
+		
+		[Test] // bug #5519
+		public void DoUseEmptyNamespacePrefixWhenApplicable ()
+		{
+			XNamespace ns = "http://jabber.org/protocol/geoloc";
+			XElement newElement = new XElement(ns + "geoloc");
+			Assert.AreEqual ("<geoloc xmlns=\"http://jabber.org/protocol/geoloc\" />", newElement.ToString (), "#1");
+		}
 	}
 }
-- 
2.11.4.GIT