RE: Have pg_basebackup write "dbname" in "primary_conninfo"?

Dear Robert,

> Seems weird to me. You don't use dbname=replication to ask for a
> replication connection, so why would we ever end up with that
> anywhere? And especially in only one of two such closely related
> cases?

Just FYI - here is an extreme case. And note that I have applied proposed patch.

When `pg_basebackup -D data_N2 -R` is used:
```
primary_conninfo = 'user=hayato ... dbname=hayato ...
```

But when `pg_basebackup -d "" -D data_N2 -R` is used:
```
primary_conninfo = 'user=hayato ... dbname=replication
```

Best Regards,
Hayato Kuroda
FUJITSU LIMITED
https://www.fujitsu.com/