id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
6436	Exception on destruction of communicator mpi_comm_null	aelaguiz@…	Matthias Troyer	"Using boost trunk mpi the communicator destructor does not check for the possibility of an MPI_COMM_NULL underlying communicator, code which produces a null underlying can exception on ref counted destruction. 

For instance, this code:

void pool(bmpi::communicator &world, bmpi::communicator &local) {
        LDEBUG(PSTR(""Pool - local: ""), pantheios::integer(local.rank()), PSTR("" of ""), pantheios::integer(local.size()));
                bmpi::group localGroup = local.group();
        dump_group(localGroup);
        
        std::vector<int> inc(1, 0);
        bmpi::group tinyGroup = localGroup.include(inc.begin(), inc.end());
        dump_group(tinyGroup);

        bmpi::communicator tinyCom(local, tinyGroup);
}        

When tinyCom goes out of scope, this exception gets thrown:

""MPI_Comm_free: MPI_ERR_COMM: invalid communicator""
"	Patches	closed	To Be Determined	mpi	Boost 1.48.0	Problem	fixed