MPI_*_get_attr family need clarification on the "flag" argument

[jaegerj]

Problem

Ahori provided this comment while reading the 4.0-RC document in 2020

MPI_*_get_attr family described the behavior of the 'flag' argument if no attribute is associated with the key, but not in the converse case.

Proposal

The explanation of the 'flag' argument is always "false if no attribute is associated with the key," but I think it should be "false if no attribute is associated with the key, true otherwise." :-)

Changes to the Text

add ', true otherwise' wherever applicable on the description of each MPI_*_get_attr

Impact on Implementations

Should be none

Impact on Users

Clearer MPI Standard

References and Pull Requests