Fixed forum-15733: Completion-list off-by-one exception in Boo interpreter

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/2.1@2454 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/BackendBindings/Boo/Boo.InterpreterAddIn/Project/CodeCompletionData.boo

@@ -115,6 +115,7 @@ internal class GlobalsCompletionDataProvider(ICSharpCode.SharpDevelop.DefaultEdi
 	
 	def constructor(interpreter as InterpreterContext):
 		_interpreter = interpreter
+		super.preSelection = ""
 		
 	override def GenerateCompletionData(fileName as string, textArea as TextArea, charTyped as System.Char) as (ICompletionData):
 		globals = _interpreter.GetGlobals()

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

@@ -7,6 +7,7 @@
 
 using System;
 using System.Drawing;
+using System.Diagnostics;
 using System.Windows.Forms;
 using ICSharpCode.TextEditor.Document;
 
@@ -280,6 +281,7 @@ namespace ICSharpCode.TextEditor.Gui.CompletionWindow
 					if (endOffset - startOffset > 0) {
 						control.Document.Remove(startOffset, endOffset - startOffset);
 					}
+					Debug.Assert(startOffset <= document.TextLength);
 					result = dataProvider.InsertAction(data, control.ActiveTextAreaControl.TextArea, startOffset, ch);
 				} finally {
 					control.EndUpdate();