fix leaked OpenedFile after creation of ViewContent fails, causes exceptions some later actions, see:

http://community.sharpdevelop.net/forums/t/15625.aspx

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/AvalonEditViewContent.cs

@@ -275,7 +275,8 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		{
 			if (trackedFeature != null)
 				trackedFeature.EndTracking();
-			this.PrimaryFile.IsDirtyChanged -= PrimaryFile_IsDirtyChanged;
+			if (PrimaryFile != null)
+				this.PrimaryFile.IsDirtyChanged -= PrimaryFile_IsDirtyChanged;
 			base.Dispose();
 			BookmarksDetach();
 			codeEditor.Dispose();

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/DefaultChangeWatcher.cs

@@ -197,8 +197,10 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			if (!disposed) {
 				if (watcher != null)
 					watcher.Dispose();
-				this.textDocument.LineTrackers.Remove(this);
-				this.textDocument.UndoStack.PropertyChanged -= UndoStackPropertyChanged;
+				if (this.textDocument != null) {
+					this.textDocument.LineTrackers.Remove(this);
+					this.textDocument.UndoStack.PropertyChanged -= UndoStackPropertyChanged;
+				}
 				disposed = true;
 			}
 		}

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

@@ -161,7 +161,8 @@ namespace ICSharpCode.SharpDevelop
 		/// <summary>Called by OpenedFile.UnregisterView to update the dictionary.</summary>
 		internal static void OpenedFileClosed(OpenedFile file)
 		{
-			if (openedFileDict[file.FileName] != file)
+			OpenedFile existing;
+			if (openedFileDict.TryGetValue(file.FileName, out existing) && existing != file)
 				throw new ArgumentException("file must be registered");
 			
 			openedFileDict.Remove(file.FileName);
@@ -217,12 +218,15 @@ namespace ICSharpCode.SharpDevelop
 			public void Invoke(string fileName)
 			{
 				OpenedFile file = FileService.GetOrCreateOpenedFile(FileName.Create(fileName));
-				IViewContent newContent = binding.CreateContentForFile(file);
-				if (newContent != null) {
-					DisplayBindingService.AttachSubWindows(newContent, false);
-					WorkbenchSingleton.Workbench.ShowView(newContent, switchToOpenedView);
+				try {
+					IViewContent newContent = binding.CreateContentForFile(file);
+					if (newContent != null) {
+						DisplayBindingService.AttachSubWindows(newContent, false);
+						WorkbenchSingleton.Workbench.ShowView(newContent, switchToOpenedView);
+					}
+				} finally {
+					file.CloseIfAllViewsClosed();
 				}
-				file.CloseIfAllViewsClosed();
 			}
 		}
 		

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

@@ -123,19 +123,24 @@ namespace ICSharpCode.SharpDevelop
 			if (view == null)
 				throw new ArgumentNullException("view");
 			
-			if (currentView != view) {
-				if (currentView == null) {
-					SwitchedToView(view);
-				} else {
-					try {
-						inLoadOperation = true;
-						using (Stream sourceStream = OpenRead()) {
-							view.Load(this, sourceStream);
+			try {
+				if (currentView != view) {
+					if (currentView == null) {
+						SwitchedToView(view);
+					} else {
+						try {
+							inLoadOperation = true;
+							using (Stream sourceStream = OpenRead()) {
+								view.Load(this, sourceStream);
+							}
+						} finally {
+							inLoadOperation = false;
 						}
-					} finally {
-						inLoadOperation = false;
 					}
 				}
+			} catch (Exception) {
+				view.Dispose();
+				throw;
 			}
 		}
 		
@@ -276,8 +281,6 @@ namespace ICSharpCode.SharpDevelop
 					currentView = newView;
 					return;
 				}
-			}
-			if (currentView != null) {
 				SaveCurrentView();
 			}
 			try {