return MPI_ERR_TYPE;
if(comm==MPI_COMM_NULL)
return MPI_ERR_COMM;
- return type->pack(inbuf, incount, outbuf,outcount,position, comm);
+ return type->pack(inbuf == MPI_BOTTOM ? nullptr : inbuf, incount, outbuf, outcount, position, comm);
}
int PMPI_Pack_size(int incount, MPI_Datatype datatype, MPI_Comm comm, int* size) {