orte/rml: ORTE_RML_SEND_COMPLETE handles messages with both NULL iov …

[ggouaillardet]

…and cbfunc.buffer

[ggouaillardet]

@rhc54
a rml_send_t created in mca_oob_tcp_recv_handler has both NULL iov and cbfunc.buffer and that caused a crash when ORTE_RML_SEND_COMPLETE is invoked.

i am not sure whether this is the right fix, or it fixes a case that should never happen.
fwiw, i was only able to run into this when invoking mpirun on a x86_64 host, and run the ibm/dynamic/spawn program on a sparcv9 host (!)

[rhc54]

It shouldn't happen, but that is a very unusual use-case, so maybe it somehow gets invoked in a strange way. Regardless, there is no harm in this protection.

[ggouaillardet]

I think the root cause is mca_oob_{usock,tcp}_send_handler do not correctly handle zero size messages.
I think we should test
if (NULL != msg->msg->iov)
instead of
if (NULL != msg->msg->data)
I will test that from tomorrow