On Open MPI 1.5.1, when I call MPI_Testsome with incount=0 and the two
output arrays NULL, I get an argument error (MPI_ERR_ARG). Is this the
intended behavior? If incount=0, no requests can complete, so the output
arrays can never be written to. I do not see anything in the MPI 2.2
standard that says either way whether this is allowed.
-- Jeremiah Willcock