DateTimeComponents.toString() incorrect during leap second

TimeScale utc = TimeScalesFactory.getUTC();
AbsoluteDate d = new AbsoluteDate("2017-01-01", utc).shiftedBy(-0.5);
DateTimeComponents dtc = d.getComponents(utc)
// the assert below fails, values are
// 2016-12-31T23:59:60.568 and 2017-01-01T00:00:00.000
Assert.assertEquals(d.toString(), dtc.toString());

// this passes, indicating the issue is in DateTimeComponents
Assert.assertEquals(d.toString(), dtc.getDate().toString() + "T" + dtc.getTime());