Re: Crash issue in PG18.5 regression

On Tue, 2026-08-18 at 14:36 -0400, Andres Freund wrote:
> FWIW, I think this is actually a bug, it just turns out that we don't
> know of
> any callers that hit it.

Committed.

Also committed the change to support collate_is_c always, for
consistency with ctype_is_c.

>
> > +/*
> > + * pg_strtitle()
> > + *
> > + * Convert src to titlecase, and return the result length (not
> > including
> > + * terminating NUL).
>
> Might not hurt to actually say what titlecase and folded strings are.

Attached follow-up patch that includes explanatory comments, and adds a
couple tiny SQL tests to cover the new examples.

>
> Sometimes that's unavoidable, because you need a server configured in
> a
> specific way, the tests take a good while and should therefore run
> concurrently, or such. But that shouldn't be the case her. Can't you
> stuff
> this into regress.c or such?

Attached new test patch that just adds it to regress.c and calls it
from misc_functions.sql.

> Other than that complaint, I'd probably backpatch this. Seems
> unlikely to be
> flappy or such?

Agreed. It would have caught 27e2afb492.

Thank you for looking at it.

Regards,
Jeff Davis