Refactor List.setRange function.

sdk/lib/utf/utf8.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.utf;
 
 const int _UTF8_ONE_BYTE_MAX = 0x7f;
 const int _UTF8_TWO_BYTE_MAX = 0x7ff;
 const int _UTF8_THREE_BYTE_MAX = 0xffff;
 
@@ skipping 72 matching lines @@
       encodedLength += 3;
     } else if (value <= UNICODE_VALID_RANGE_MAX) {
       encodedLength += 4;
     }
   }
 
   List<int> encoded = new List<int>(encodedLength);
   int insertAt = 0;
   for (int value in source) {
     if (value < 0 || value > UNICODE_VALID_RANGE_MAX) {
-      encoded.setRange(insertAt, 3, [0xef, 0xbf, 0xbd]);
+      encoded.setRange(insertAt, insertAt + 3, [0xef, 0xbf, 0xbd]);
       insertAt += 3;
     } else if (value <= _UTF8_ONE_BYTE_MAX) {
       encoded[insertAt] = value;
       insertAt++;
     } else if (value <= _UTF8_TWO_BYTE_MAX) {
       encoded[insertAt] = _UTF8_FIRST_BYTE_OF_TWO_BASE | (
           _UTF8_FIRST_BYTE_OF_TWO_MASK &
           _addToEncoding(insertAt, 1, value, encoded));
       insertAt += 2;
     } else if (value <= _UTF8_THREE_BYTE_MAX) {
@@ skipping 162 matching lines @@
       return true;
     } else if (replacementCodepoint != null) {
       _current = replacementCodepoint;
       return true;
     } else {
       throw new ArgumentError(
           "Invalid UTF8 at ${utf8EncodedBytesIterator.position - j}");
     }
   }
 }