Re: Crash issue in PG18.5 regression

Hi,

On 2026-08-11 16:04:15 -0400, Tom Lane wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
> > It also seems like we really ought to have an actually reachable, currently
> > crashing, to_date() call in the tests? It seems concerning that
> > seq_search_localized(), casefold_str_cmp() are completely uncovered today, and
> > quite obviously we can't be relied upon to get this right.
>
> All that code is reached when I run the core regression tests under
> LANG=C.utf8 or LANG=en_US.utf8, except for the "As last resort"
> stanza at the bottom of seq_search_localized()'s loop. I suppose the
> coverage.postgresql.org animal is either not Linux or doesn't test
> any UTF8 encoding, but that's not the fault of our test cases, and
> it doesn't reflect what I think actually happens in the buildfarm.

I tested locally on a database that triggered the problem, the skip condition
query was true, which lead me to hastily misread what the query is trying to
do. Turns out the reason it doesn't run here - and likely the reason that it
doesn't run for coverage.pg.o - is that the test afaict *never* matches for a
meson build :(

no_enc2[3902736][1]=# SELECT version();
┌────────────────────────────────────────────────────────────────────┐
│ version │
├────────────────────────────────────────────────────────────────────┤
│ PostgreSQL 20devel on x86_64-linux, compiled by gcc-16.1.0, 64-bit │
└────────────────────────────────────────────────────────────────────┘
(1 row)

That will obviously never match "linux-gnu".

I guess I should start a separate thread about that.

Greetings,

Andres Freund