Fixed SD2-1207 - Closing a file with the code completion window still open disposes the text editor before the completion window causing a null reference exception. The AbstractCodeCompletion window now checks that TextAreaControl's scroll bars are not null when it closes.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@2060 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Libraries/ICSharpCode.TextEditor/Project/Src/Gui/CompletionWindow/AbstractCompletionWindow.cs

@@ -170,8 +170,12 @@ namespace ICSharpCode.TextEditor.Gui.CompletionWindow
 			// take out the inserted methods
 			parentForm.LocationChanged -= new EventHandler(ParentFormLocationChanged);
 			
+			if (control.ActiveTextAreaControl.VScrollBar != null) {
 				control.ActiveTextAreaControl.VScrollBar.ValueChanged -= new EventHandler(ParentFormLocationChanged);
+			}
+			if (control.ActiveTextAreaControl.HScrollBar != null) {
 				control.ActiveTextAreaControl.HScrollBar.ValueChanged -= new EventHandler(ParentFormLocationChanged);
+			}
 			
 			control.ActiveTextAreaControl.TextArea.LostFocus          -= new EventHandler(this.TextEditorLostFocus);
 			control.ActiveTextAreaControl.Caret.PositionChanged       -= new EventHandler(CaretOffsetChanged);