ICSharpCode.AvalonEdit.TextEditor.OnIsModifiedChanged C# (CSharp) Method

        static void OnIsModifiedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            TextEditor editor = d as TextEditor;
            if (editor != null) {
                TextDocument document = editor.Document;
                if (document != null) {
                    UndoStack undoStack = document.UndoStack;
                    if ((bool)e.NewValue) {
                        if (undoStack.IsOriginalFile)
                            undoStack.DiscardOriginalFileMarker();
                    } else {
                        undoStack.MarkAsOriginalFile();
                    }
                }
            }
        }