Fix null reference when creating new EF data model file.

Do not add an EntityTypeMapping element if it already exists.
Fix intermittent error were the EF data model view content
does not have a workbench window when the file is renamed
on save.

src/AddIns/DisplayBindings/Data/ICSharpCode.Data.EDMDesigner.Core/IO/MSLIO.cs

@@ -25,10 +25,6 @@ namespace ICSharpCode.Data.EDMDesigner.Core.IO
 {
     public class MSLIO : IO
     {
-        #region Methods
-
-        #region Read
-
         public static XDocument GenerateTypeMapping(XDocument mslDocument)
         {
             XElement mappingElement = mslDocument.Element(XName.Get("Mapping", mslNamespace.NamespaceName));
@@ -41,8 +37,10 @@ namespace ICSharpCode.Data.EDMDesigner.Core.IO
             if (entityContainerMappingElement == null || entityContainerMappingElement.IsEmpty)
                 return null;
 
-            foreach (XElement entitySetMapping in entityContainerMappingElement.Elements(mslNamespace + "EntitySetMapping"))
-            {
+            foreach (XElement entitySetMapping in entityContainerMappingElement.Elements(mslNamespace + "EntitySetMapping")) {
+            	if (entitySetMapping.HasEntityTypeMappingChildElement())
+            		continue;
+            	
                 string name = entitySetMapping.Attribute("Name").Value;
                 string storeEntitySet = entitySetMapping.Attribute("StoreEntitySet").Value;
                 string typeName = entitySetMapping.Attribute("TypeName").Value;
@@ -61,7 +59,7 @@ namespace ICSharpCode.Data.EDMDesigner.Core.IO
 
             return mslDocument;
         }
-
+        
         public static CSDLContainer IntegrateMSLInCSDLContainer(CSDLContainer csdlContainer, SSDLContainer ssdlContainer, XElement edmxRuntime)
         {
             XElement mappingsElement = edmxRuntime.Element(XName.Get("Mappings", edmxNamespace.NamespaceName));
@@ -263,10 +261,6 @@ namespace ICSharpCode.Data.EDMDesigner.Core.IO
             }
         }
 
-        #endregion
-
-        #region Write
-
         public static XElement Write(EDM edm)
         {
             CSDLContainer csdlContainer = edm.CSDLContainer;
@@ -533,10 +527,6 @@ namespace ICSharpCode.Data.EDMDesigner.Core.IO
                     new XAttribute("ColumnName", result.Value));
             }
         }
-
-        #endregion 
-
-        #endregion
     }
 
     #region Extension methods
@@ -560,6 +550,11 @@ namespace ICSharpCode.Data.EDMDesigner.Core.IO
 
             return element;
         }
+        
+		public static bool HasEntityTypeMappingChildElement(this XElement entitySetMapping)
+		{
+			return entitySetMapping.Elements().Any(e => e.Name.LocalName == "EntityTypeMapping");
+		}
     }
 
     #endregion

src/Main/Base/Project/Src/Services/File/FileService.cs

@@ -149,7 +149,8 @@ namespace ICSharpCode.SharpDevelop
 			if (openedFileDict.ContainsKey(newName)) {
 				OpenedFile oldFile = openedFileDict[newName];
 				if (oldFile.CurrentView != null) {
-					oldFile.CurrentView.WorkbenchWindow.CloseWindow(true);
+					if (oldFile.CurrentView.WorkbenchWindow != null)
+						oldFile.CurrentView.WorkbenchWindow.CloseWindow(true);
 				} else {
 					throw new ArgumentException("there already is a file with the newName");
 				}