IndexSet hinting bug

range_start.js

var hintSize = SC.IndexSet.HINT_SIZE,
    start, set;

set = SC.IndexSet.create();

set.add(1);
set.add(hintSize + 1);

// Before adding 2,
// the internal data structure looks like:
// {
//   0  : -  1,   // Hole until 1
//   1  :    2,   // End of range is 2
//   2  : -257,   // Hole until 257
//   256:    2,   // Hint points at index 2, which is ok.
//   257:  258,   // End of range is 258
//   258:    0    // End of index set
// }
equals(set.rangeStartForIndex(hintSize),
       set.rangeStartForIndex(hintSize - 1));

set.add(2);

// Assuming SC.IndexSet.HINT_SIZE is 256,
// the internal data structure looks like:
// {
//   0  : -  1,   // Hole until 1
//   1  :    3,   // End of range is 3
//   3  : -257,   // Hole until 257
//   256:    2,   // Hint points at index 2, which is invalid.
//   257:  258,   // End of range is 258
//   258:    0    // End of index set
// }

equals(set.rangeStartForIndex(hintSize),
       set.rangeStartForIndex(hintSize - 1));