Bug in pg_hba.conf or pg_basebackup concerning replication connections

All,

If I have the following line in pg_hba.conf:

host replication replication all md5

pg_basebackup -x -v -P -h master1 -U replication -D $PGDATA
pg_basebackup: could not connect to server: FATAL: no pg_hba.conf entry for replication connection from host "216.121.61.233", user "replication"

But, if I change it to "all" users, replication succeeds:

host replication all all md5

... even if the user "postgres" (the only other user in this test) is declared "with noreplication".

I can't figure out what's going wrong here; either HBA is broken and won't accept a replication line unless user is "all", or pgbasebackup is doing something to test a connection as "postgres", even though no such connection attempt shows up in the logs.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com
San Francisco