Horton

Re: Latest patches break one of our unit-test, related to RLS

Laurenz Albe <laurenz.albe@cybertec.at>

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From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Tom Lane <tgl@sss.pgh.pa.us>, Dominique Devienne <ddevienne@gmail.com>
Cc: pgsql-general@postgresql.org
Date: 2025-09-12T23:34:08Z
Lists: pgsql-general

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On Fri, 2025-09-12 at 10:07 -0400, Tom Lane wrote:
> Dominique Devienne <ddevienne@gmail.com> writes:
> > > This DOES look like a bug, no? I've done regexes for a long time,
> > > and these two forms should be equivalent IMHO. --DD
> 
> Yeah, I agree it's busted.  You can use EXPLAIN VERBOSE to see the
> translated-to-POSIX pattern, and it's wrong:
> 
> regression=# explain verbose with t(v) as (values ('foo:bar'), ('foo/bar'), ('foo0bar'))                                         
> select v from t where v similar to 'foo[\d\w]_%';
>                           QUERY PLAN                          
> --------------------------------------------------------------
>  Values Scan on "*VALUES*"  (cost=0.00..0.05 rows=1 width=32)
>    Output: "*VALUES*".column1
>    Filter: ("*VALUES*".column1 ~ '^(?:foo[\d\w]_%)$'::text)
> (3 rows)
> 
> The _ and % are not getting converted to their POSIX equivalents
> ("." and ".*").

Indeed, and I have to take the blame for introducing a bug in a minor
release :^(

The attached patch should fix the problem.

Yours,
Laurenz Albe

Commits

  1. Amend recent fix for SIMILAR TO regex conversion.

  2. Fix conversion of SIMILAR TO regexes for character classes