Implement correct scoping rules for variables.

sdk/lib/collection/list.dart

 // Copyright (c) 2013, 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.collection;
 
 /**
  * Abstract implementation of a list.
  *
  * All operations are defined in terms of `length`, `operator[]`,
@@ skipping 297 matching lines @@
   void _rangeCheck(int start, int end) {
     if (start < 0 || start > this.length) {
       throw new RangeError.range(start, 0, this.length);
     }
     if (end < start || end > this.length) {
       throw new RangeError.range(end, start, this.length);
     }
   }
 
   List<E> sublist(int start, [int end]) {
-    if (end == null) end = length;
+    if (end == null) end = this.length;
     _rangeCheck(start, end);
     int length = end - start;
     List<E> result = new List<E>()..length = length;
     for (int i = 0; i < length; i++) {
       result[i] = this[start + i];
     }
     return result;
   }
 
   Iterable<E> getRange(int start, int end) {
@@ skipping 157 matching lines @@
       result.writeAll(this, ', ');
       result.write(']');
      } finally {
        assert(identical(_toStringList.last, this));
        _toStringList.removeLast();
      }
 
     return result.toString();
   }
 }