Yes, I had already realized, sorry about the question.
It seems however, that for some MPI implementations (LAM in
particular) a NULL pointer is assumed to be like a pointer to
MPI_REQUEST_NULL, and my program ran fine with them. I have corrected
my program and all works fine with Open MPI. Thanks
I think you are mixing up two different things here: a NULL pointer is
invalid, and thus Open MPI has to raise an error. If a request is
MPI_REQUEST_NULL, that's perfectly legal according to the standard.
However MPI_REQUEST_NULL is not a NULL pointer, its a well defined value.
Francisco Jesús
