Fix #51: caret movement when inserting new line with DefaultIndentationStrategy and there are spaces to the right of the caret

Author: dgrunwald

ICSharpCode.AvalonEdit/Indentation/DefaultIndentationStrategy.cs

@@ -41,7 +41,9 @@ public virtual void IndentLine(TextDocument document, DocumentLine line)
 				string indentation = document.GetText(indentationSegment);
 				// copy indentation to line
 				indentationSegment = TextUtilities.GetWhitespaceAfter(document, line.Offset);
-				document.Replace(indentationSegment, indentation);
+				document.Replace(indentationSegment.Offset, indentation.Length, indentation,
+				                 OffsetChangeMappingType.RemoveAndInsert);
+				// OffsetChangeMappingType.RemoveAndInsert guarantees the caret moves behind the new indentation.
 			}
 		}