Re: pg_dump assertion failure with "-n pg_catalog"

On Tue, 2023-09-05 at 11:45 +0200, Peter Eisentraut wrote:
> This new code replaces an (unexpected) null value with an empty
> string.
> Is that correct?  Empty locale strings have specific behaviors under
> the
> libc and icu providers.  It seems to me it would be better to error
> out
> or don't print a CREATE COLLATION command at all rather than
> substituting a value that is not a correct substitute.

It already issues a warning, which seemed more consistent with other
unexpected situations in pg_dump.

> Alternatively, a more correct way to produce a null value would be to
> not issue the assignment at all (omit the " lc_collation = " etc.).
> Then we can leave it up to the backend to accept the command or not,
> but
> at least the dump closely reflects the original catalog state.

The backend does not accept a collation specified with lc_ctype and not
lc_collate (or vice versa), so it would be an un-restorable dump. That
doesn't seem great.

Regards,
    Jeff Davis