Don't create an unnecessary copy of the whole text buffer when showing a tooltip on the ChangeMargin

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

@@ -200,7 +200,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 					differ.editor.Visibility = Visibility.Collapsed;
 					differ.copyButton.Visibility = Visibility.Collapsed;
 				} else {
-					var baseDocument = new TextDocument(changeWatcher.BaseDocument.Text);
+					var baseDocument = new TextDocument(DocumentUtilitites.GetTextSource(changeWatcher.BaseDocument));
 					if (differ.editor.SyntaxHighlighting != null) {
 						var mainHighlighter = new DocumentHighlighter(baseDocument, differ.editor.SyntaxHighlighting.MainRuleSet);
 						var popupHighlighter = differ.editor.TextArea.GetService(typeof(IHighlighter)) as DocumentHighlighter;

src/Main/Base/Project/Src/Util/ExtensionMethods.cs

@@ -311,13 +311,13 @@ namespace ICSharpCode.SharpDevelop
 		public static Point TransformToDevice(this Point point, Visual visual)
 		{
 			Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformToDevice;
-			return new Point(point.X * matrix.M11, point.Y * matrix.M22);
+			return matrix.Transform(point);
 		}
 		
 		public static Point TransformFromDevice(this Point point, Visual visual)
 		{
 			Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformFromDevice;
-			return new Point(point.X * matrix.M11, point.Y * matrix.M22);
+			return matrix.Transform(point);
 		}
 		#endregion