GhostZoneWidth not working with values > 1 (HiParSimulator, unstructured topology, DistributedPTScotchUnstructured)

[klreuther]

When I set a GhostZoneWidth > 1 (tested with a value of 5) strange things start to happen:

For an object lying in the ghost zone, the nanostep sequence is set back several times, connected with bogus data in the neighborhood (oldGrid).

Nanostep order for one object observed in the debugger:
0, 1, 2, 0(!), 1, 2, 3, 4, 5, 6, 7, 5(!), 6, 7, 8, 9, 10, 11.
(number of nanosteps is 12).

At the second "set-back" (i.e., the second execution of nanostep 5) there is definitely bogus (appears uninitialized) data in the neighborhood. I did not check whether this is also the case in the first set-back.

GhostZoneWidth of 1 works fine, though.