pg_upgrade if 'postgres' database is dropped

pg_upgrade doesn't work if the 'postgres' database has been dropped in 
the old cluster:

~/pgsql.master$ bin/pg_upgrade -b ~/pgsql.91stable/bin -B bin/ -d 
~/pgsql.91stable/data -D data-upgraded/
Performing Consistency Checks
-----------------------------
Checking current, bin, and data directories                 ok
Checking cluster versions                                   ok
Checking database user is a superuser                       ok
Checking for prepared transactions                          ok
Checking for reg* system OID user data types                ok
Checking for contrib/isn with bigint-passing mismatch       ok
Creating catalog dump                                       ok
Checking for prepared transactions                          ok

New cluster database "postgres" does not exist in the old cluster
Failure, exiting


That's a bit unfortunate. We have some other tools that don't work 
without the 'postgres' database, like 'reindexdb -all', but it would 
still be nice if pg_upgrade did.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com