[Mpi3-ft] MPI_Comm_validate() protection

[Josh Hursey]

In 17.7.1 the proposal states:
  "All collective communication operations initiated before the call
to MPI_COMM_VALIDATE must also complete before it is called, and no
collective calls may be initiated until it has completed."

Considering the case where FailHandlers are used in the 'ALL'
operating mode. In this mode, a user may want to call validate in all
of the FailHanlders to synchronize them. But if the FailHandler was
triggered out of a collective operation over a communicator that does
-not- include the failed process then the user cannot write a correct
program (since they cannot cancel, and may not be able to complete the
collective operation).

My suggestion is that we remove this sentence. Do folks have a problem
with this?

Thanks,
Josh

-- 
Joshua Hursey
Postdoctoral Research Associate
Oak Ridge National Laboratory
http://users.nccs.gov/~jjhursey