[MPICH] empty group returned by MPI_Group_excl

[Toon Knapen]

Hi all,

I noticed that there is a test in test/mpi/group/grouptest.c of 
mpich2-1.0.5p4 that verifies that a group of which all ranks are 
excluded (using MPI_Group_excl) is equal to MPI_GROUP_EMPTY.

Is this really required by the standard? AFAICT the standard does not 
require that an empty group is equal to MPI_GROUP_EMPTY (both groups of 
course will be MPI_IDENT).

Thanks in advance,

Toon Knapen