Removes namespace attributes from child nodes in the pasted snippet if they are already present in the root where the snippet is pasted.

Added a test "PasteCustomControlUsingMixedTypes" that failed before this fix.

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Tests/Designer/EditOperationTests.cs

@@ -4,6 +4,8 @@
 using System;
 using System.Threading;
 using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Markup;
 
 using ICSharpCode.WpfDesign.Designer.Xaml;
 using ICSharpCode.WpfDesign.XamlDom;
@@ -14,6 +16,15 @@ namespace ICSharpCode.WpfDesign.Tests.Designer
 	[TestFixture]
 	public class EditOperationTests : ModelTestHelper
 	{
+		protected override XamlLoadSettings CreateXamlLoadSettings()
+		{
+			var settings = base.CreateXamlLoadSettings();
+			
+			settings.TypeFinder.RegisterAssembly(typeof(NamespaceTests).Assembly);
+			
+			return settings;
+		}
+		
 		Mutex mutex;
 		
 		[TestFixtureSetUp]
@@ -204,5 +215,57 @@ namespace ICSharpCode.WpfDesign.Tests.Designer
 			Assert.IsNotNull(nameScope.FindName(_name + "_Copy3"));
 			Assert.IsNull(nameScope.FindName(_name + "_Copy4"));
 		}
+		
+		[Test]
+		public void PasteCustomControlUsingMixedTypes()
+		{
+			DesignItem grid = CreateGridContextWithDesignSurface("<Button/>");
+			DesignItem myButton = grid.Services.Component.RegisterComponentForDesigner(new ICSharpCode.WpfDesign.Tests.Controls.CustomButton());
+			grid.Properties["Children"].CollectionElements.Add(myButton);
+			
+			DesignItem extensionItem = grid.Services.Component.RegisterComponentForDesigner(new MyExtension());
+			extensionItem.Properties["MyProperty1"].SetValue(new Button());
+			myButton.Properties[ICSharpCode.WpfDesign.Tests.Controls.CustomButton.TagProperty].SetValue(extensionItem);
+			
+			var xamlContext = grid.Context as XamlDesignContext;
+			Assert.IsNotNull(xamlContext);
+			xamlContext.XamlEditAction.Copy(new[] {myButton});
+			
+			grid = CreateGridContextWithDesignSurface("<Button/>");
+			xamlContext = grid.Context as XamlDesignContext;
+			Assert.IsNotNull(xamlContext);
+			var selection = grid.Services.Selection;
+			selection.SetSelectedComponents(new[] {grid});
+			xamlContext.XamlEditAction.Paste();
+
+			string expectedXaml = "<Button />\n" +
+								  "<sdtcontrols:CustomButton>\n" +
+								  "  <sdtcontrols:CustomButton.Tag>\n" +
+								  "    <Controls0:MyExtension>\n" +
+								  "      <Controls0:MyExtension.MyProperty1>\n" +
+								  "        <Button />\n" +
+								  "      </Controls0:MyExtension.MyProperty1>\n" +
+								  "    </Controls0:MyExtension>\n" +
+								  "  </sdtcontrols:CustomButton.Tag>\n" +
+								  "</sdtcontrols:CustomButton>\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\"");
+		}
+	}
+	
+	public class MyExtension : MarkupExtension
+	{
+		public MyExtension()
+		{
+		}
+
+		public override object ProvideValue(IServiceProvider serviceProvider)
+		{
+			return null;
+		}
+		
+		public object MyProperty1 { get; set; }
 	}
 }

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Tests/Designer/ModelTestHelper.cs

@@ -30,7 +30,7 @@ namespace ICSharpCode.WpfDesign.Tests.Designer
 		protected XamlDesignContext CreateContext(string xaml)
 		{
 			log = new StringBuilder();
-			XamlDesignContext context = new XamlDesignContext(new XmlTextReader(new StringReader(xaml)), new XamlLoadSettings());
+			XamlDesignContext context = new XamlDesignContext(new XmlTextReader(new StringReader(xaml)), CreateXamlLoadSettings());
 			/*context.Services.Component.ComponentRegistered += delegate(object sender, DesignItemEventArgs e) {
 				log.AppendLine("Register " + ItemIdentity(e.Item));
 			};
@@ -78,19 +78,7 @@ namespace ICSharpCode.WpfDesign.Tests.Designer
 				expectedXaml.Replace("\r", "").Replace("\n", "\n  ")
 				+ "\n</Canvas>";
 			
-			StringWriter stringWriter = new StringWriter();
-			XmlTextWriter xmlWriter = new XmlTextWriter(stringWriter);
-			xmlWriter.Formatting = Formatting.Indented;
-			context.Save(xmlWriter);
-			
-			string actualXaml = stringWriter.ToString().Replace("\r", "");;
-			if (expectedXaml != actualXaml) {
-				Debug.WriteLine("expected xaml:");
-				Debug.WriteLine(expectedXaml);
-				Debug.WriteLine("actual xaml:");
-				Debug.WriteLine(actualXaml);
-			}
-			Assert.AreEqual(expectedXaml, actualXaml);
+			AssertDesignerOutput(expectedXaml, context);
 		}
 		
 		protected DesignItem CreateGridContext(string xaml)
@@ -107,16 +95,51 @@ namespace ICSharpCode.WpfDesign.Tests.Designer
 			var surface = new DesignSurface();
 			var xamlWithGrid=@"<Grid xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation"" xmlns:x=""http://schemas.microsoft.com/winfx/2006/xaml"" >
             " + xaml + "</Grid>";
-			surface.LoadDesigner(new XmlTextReader(new StringReader(xamlWithGrid)), new XamlLoadSettings());
+			surface.LoadDesigner(new XmlTextReader(new StringReader(xamlWithGrid)), CreateXamlLoadSettings());
 			Assert.IsNotNull(surface.DesignContext.RootItem);
 			return surface.DesignContext.RootItem;
 		}
 		
+		protected void AssertGridDesignerOutput(string expectedXaml, DesignContext context, params String[] additionalXmlns)
+		{
+			string gridStartTag = "<Grid xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\" xmlns:x=\"http://schemas.microsoft.com/winfx/2006/xaml\"";
+			
+			foreach(string ns in additionalXmlns) {
+				gridStartTag += " " + ns;
+			}
+
+			expectedXaml = gridStartTag + ">\n" + expectedXaml.Trim();
+			
+			expectedXaml =
+				"<?xml version=\"1.0\" encoding=\"utf-16\"?>\n" +
+				expectedXaml.Replace("\r", "").Replace("\n", "\n  ")
+				+ "\n</Grid>";
+			
+			AssertDesignerOutput(expectedXaml, context);
+		}
+		
 		static string ItemIdentity(DesignItem item)
 		{
 			return item.ComponentType.Name + " (" + item.GetHashCode() + ")";
 		}
 		
+		protected void AssertDesignerOutput(string expectedXaml, DesignContext context)
+		{
+			StringWriter stringWriter = new StringWriter();
+			XmlTextWriter xmlWriter = new XmlTextWriter(stringWriter);
+			xmlWriter.Formatting = Formatting.Indented;
+			context.Save(xmlWriter);
+			
+			string actualXaml = stringWriter.ToString().Replace("\r", "");;
+			if (expectedXaml != actualXaml) {
+				Debug.WriteLine("expected xaml:");
+				Debug.WriteLine(expectedXaml);
+				Debug.WriteLine("actual xaml:");
+				Debug.WriteLine(actualXaml);
+			}
+			Assert.AreEqual(expectedXaml, actualXaml);
+		}
+		
 		protected void AssertLog(string expectedLog)
 		{
 			expectedLog = expectedLog.Replace("\r", "");
@@ -129,5 +152,10 @@ namespace ICSharpCode.WpfDesign.Tests.Designer
 			}
 			Assert.AreEqual(expectedLog, actualLog);
 		}
+		
+		protected virtual XamlLoadSettings CreateXamlLoadSettings()
+		{
+			return new XamlLoadSettings();
+		}
 	}
 }

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.XamlDom/Project/XamlParser.cs

@@ -605,6 +605,39 @@ namespace ICSharpCode.WpfDesign.XamlDom
 				scope.OwnerDocument.GetTypeDescriptorContext(scope), valueText);
 		}
 		
+		/// <summary>
+		/// Removes namespace attributes defined in the root from the specified node and all child nodes.
+		/// </summary>
+		static void RemoveRootNamespacesFromNodeAndChildNodes(XamlObject root, XmlNode node)
+		{
+			foreach (XmlNode childNode in node.ChildNodes) {
+				RemoveRootNamespacesFromNodeAndChildNodes(root, childNode);
+			}
+
+			if (node.Attributes != null) {
+				List<XmlAttribute> removeAttributes = new List<XmlAttribute>();
+				foreach (XmlAttribute attrib in node.Attributes) {
+					if (attrib.Name.StartsWith("xmlns:")) {
+						var rootPrefix = root.OwnerDocument.GetPrefixForNamespace(attrib.Value);
+						if (rootPrefix == null) {
+							//todo: check if we can add to root, (maybe same ns exists)
+							root.OwnerDocument.XmlDocument.Attributes.Append((XmlAttribute)attrib.CloneNode(true));
+							removeAttributes.Add(attrib);
+						}
+						else if (rootPrefix == attrib.Name.Substring("xmlns:".Length)) {
+							removeAttributes.Add(attrib);
+						}
+					}
+					else if (attrib.Name == "xmlns" && attrib.Value == XamlConstants.PresentationNamespace) {
+						removeAttributes.Add(attrib);
+					}
+				}
+				foreach (var removeAttribute in removeAttributes) {
+					node.Attributes.Remove(removeAttribute);
+				}
+			}
+		}
+		
 		/// <summary>
 		/// Method use to parse a piece of Xaml.
 		/// </summary>
@@ -625,25 +658,8 @@ namespace ICSharpCode.WpfDesign.XamlDom
 				}
 				if(xmlnsAttribute!=null)
 					element.Attributes.Remove(xmlnsAttribute);
-
-				//Remove namespace Attributes defined in the Xaml Root from the Pasted Snippet!
-				List<XmlAttribute> removeAttributes = new List<XmlAttribute>();
-				foreach (XmlAttribute attrib in element.Attributes) {
-					if (attrib.Name.StartsWith("xmlns:")) {
-						var rootPrefix = root.OwnerDocument.GetPrefixForNamespace(attrib.Value);
-						if (rootPrefix == null) {
-							//todo: check if we can add to root, (maybe same ns exists)
-							root.OwnerDocument.XmlDocument.Attributes.Append((XmlAttribute)attrib.CloneNode(true));
-							removeAttributes.Add(attrib);
-						} else if (rootPrefix == attrib.Name.Substring(6)) {
-							removeAttributes.Add(attrib);
-						}
-					}
-				}
-				foreach (var removeAttribute in removeAttributes) {
-					element.Attributes.Remove(removeAttribute);
-				}
-				//end remove
+				
+				RemoveRootNamespacesFromNodeAndChildNodes(root, element);
 				
 				XamlParser parser = new XamlParser();
 				parser.settings = settings;