Re: [PATCH] Add a check_hook for output_plugin_libraries

On Thu, Sep 24, 2026 at 7:46 PM Hayato Kuroda (Fujitsu)
<kuroda(dot)hayato(at)fujitsu(dot)com> wrote:
> ```
> + /*
> + * XXX SplitGUCList won't respect guc_malloc requirements, but this is
> + * consistent with other check_hook implementations...
> + */
> ```
>
> Let me clarify: it's because the SplitGUCList()->lappend() can raise OOM error,
> right?

Right.

> Is the same check in StartupDecodingContext() still needed? I.e. we can check the returned value
> by Assert() here.

Ah, thanks. I think we should avoid relying on assertions in
security-critical code, but I've simplified the dead code path to an
elog(ERROR).

> +# check.c assumes the list syntax of output_plugin_libraries is validated by the
> +# server, so take a moment to confirm that now. (This is difficult to test via
> +# regression suite, because our SET grammar won't accept the bad syntax.)
> ```
>
> Per my experiment, an SQL function set_config() is usable. So can't we put in guc.sql?
> PSA my idea.

Thank you! I completely forgot about set_config(); that should make
backpatching much simpler. I applied your patch with is_local set to
true instead of false, so a regression failure won't change state for
later tests in the file.

v2 attached.

Thanks,
--Jacob