According to the MPI Standard, "only arguments sendbuf, sendcount,
sendtype, root, and comm are significant" on non-root processes in
MPI_Gather. However, in routine "ompi_coll_tuned_gather_intra_binomial"
the value of "rdtype" ("recvtype" of MPI_Gather) is used. This leads to
crash if an uninitialized value is used.
The problem exists in version 1.4.1.