/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *

 *  (C) 2003 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <stdio.h>

#include "mpitest.h"

int main(int argc, char *argv[])

{

    int errs = 0;

    int size, dims[2], periods[2], remain[2];

    int result, rank;

    MPI_Comm comm, newcomm;

    MTest_Init(&argc, &argv);

    /* First, create a 1-dim cartesian communicator */

    periods[0] = 0;

    MPI_Comm_size(MPI_COMM_WORLD, &size);

    dims[0] = size;

    MPI_Cart_create(MPI_COMM_WORLD, 1, dims, periods, 0, &comm);

    /* Now, extract a communicator with no dimensions */

    remain[0] = 0;

    MPI_Cart_sub(comm, remain, &newcomm);

    MPI_Comm_rank(comm, &rank;;

    if (rank == 0) {

        /* This should be congruent to MPI_COMM_SELF */

        MPI_Comm_compare(MPI_COMM_SELF, newcomm, &result);

        if (result != MPI_CONGRUENT) {

            errs++;

            printf("cart sub to size 0 did not give self\n");

        }

        MPI_Comm_free(&newcomm);

    } else if (newcomm != MPI_COMM_NULL) {

        errs++;

        printf("cart sub to size 0 did not give null\n");

    }

    /* Free the new communicator so that storage leak tests will

     * be happy */

    MPI_Comm_free(&comm);

    MTest_Finalize(errs);

    return MTestReturnValue(errs);

}