Re: [PATCH] initdb: Treat empty -U argument as unset username

Hi hackers,

Based on the suggestion that we should explicitly reject empty usernames
instead of silently falling back, I’ve updated the patch accordingly.

### Changes in v2:

- `initdb` now errors out immediately if the `-U` or `--username` argument
is an empty string.
- The error message is:

superuser name must not be empty

- A regression test is added to `src/bin/initdb/t/001_initdb.pl` to verify
that the case `initdb -U ''` fails as expected.

This approach avoids any ambiguity about whether an empty username is
valid, and fails early with a clear message. It also brings consistency
with existing checks, such as the one disallowing superuser names starting
with `pg_`.

Let me know if this looks acceptable or if further refinement is needed.

Patch attached.

Best regards,
Jianghua Yang

Daniel Gustafsson <daniel(at)yesql(dot)se> 于2025年7月2日周三 00:16写道：

> > On 2 Jul 2025, at 06:31, Robert Treat <rob(at)xzilla(dot)net> wrote:
>
> > FWIW, I tend to agree with David; I feel like if a user passes in -U,
> > there was probably a reason, and a good error message would be more
> > useful in clarifying things rather than blindly pushing forward with
> > potentially the wrong thing.
>
> Agreed, and it's not even clear that the previous code was intentionally
> trying
> to allow an empty -U. An improved error message would be a good patch
> though.
>
> --
> Daniel Gustafsson
>
>