fix unit tests

Author: jogibear9988

WpfDesign.Designer/Tests/Designer/EditOperationTests.cs

@@ -265,8 +265,8 @@ public void PasteCustomControlUsingMixedTypes()
 								  "</sdtcontrols:CustomButton>\n";
 
 			AssertGridDesignerOutput(expectedXaml, grid.Context,
-									"xmlns:sdtcontrols=\"http://sharpdevelop.net/WpfDesign/Tests/Controls\"",
-									"xmlns:Controls0=\"clr-namespace:ICSharpCode.WpfDesign.Tests.Designer;assembly=ICSharpCode.WpfDesign.Tests\"");
+									"xmlns:Controls0=\"clr-namespace:ICSharpCode.WpfDesign.Tests.Designer;assembly=ICSharpCode.WpfDesign.Tests\"",
+									"xmlns:sdtcontrols=\"http://sharpdevelop.net/WpfDesign/Tests/Controls\"");
 		}
 
 		[Test]
@@ -294,8 +294,8 @@ public void PasteCustomControlUsingStaticResource()
 								  "<sdtcontrols:CustomButton Tag=\"{StaticResource res1}\" />\n";
 
 			AssertGridDesignerOutput(expectedXaml, grid.Context,
-			                         "xmlns:Controls0=\"clr-namespace:ICSharpCode.WpfDesign.Tests.Designer;assembly=ICSharpCode.WpfDesign.Tests\"",
-			                         "xmlns:sdtcontrols=\"http://sharpdevelop.net/WpfDesign/Tests/Controls\"");
+			                        "xmlns:Controls0=\"clr-namespace:ICSharpCode.WpfDesign.Tests.Designer;assembly=ICSharpCode.WpfDesign.Tests\"",
+									"xmlns:sdtcontrols=\"http://sharpdevelop.net/WpfDesign/Tests/Controls\"");
 
 			var xamlContext = grid.Context as XamlDesignContext;
 			Assert.IsNotNull(xamlContext);

WpfDesign.XamlDom/Project/XamlObject.cs

@@ -139,6 +139,8 @@ internal XmlAttribute XmlAttribute {
 
 		string GetPrefixOfNamespace(string ns, XmlElement target)
 		{
+			if (target.NamespaceURI == ns)
+				return null;
 			var prefix = target.GetPrefixOfNamespace(ns);
 			if (!string.IsNullOrEmpty(prefix))
 				return prefix;