Proposal: improve shutdown during online backup

I'm referring to the discussion in this thread:
http://archives.postgresql.org/pgsql-hackers/2007-11/msg00946.php

As expressed in the thread, I think that there should not be
a backup_label file in the data directory after a clean shutdown,
because
a) it's probably an oversight anyway (someone forgot to
call pg_stop_backup) and
b) it will force an unnecessary recovery at server restart,
which will sometimes fail (if the WAL file is no longer there).

This is my proposal:

1) On "pg_ctl stop|restart -m smart", check if online backup is
in progress and do not shutdown in this case (treat the online
backup like an open connection).
2) On "pg_ctl stop|restart -m fast", remove backup_label after
the server has been brought down successfully.

If that's acceptable, I'd be willing to work on it.

Yours,
Laurenz Albe