anchor.diff:          stop = false;
         }
   
  +      // Move nodes from left to right.
         while (aStartNode.key == bEndNode.key) {
           aStartNode.update(bEndNode, context);
   
  
positive.code:         stop = false;
        }
  
        // suffix
        while (aEndNode.key == bEndNode.key) {
          aEndNode.update(bEndNode, context);
  
  
negative.code:       aNode.update(bNode, context);
      }
  
      // Update nodes with the same type at the end.
      while (aStart <= aEnd && bStart <= bEnd) {
        final aNode = a[aEnd];
        final bNode = b[bEnd];
  