Re: pg_logical_slot_peek_changes crashes postgres when called from inside pl/pgsql

On 2017-10-06 21:24:34 -0700, Ben Chobot wrote:
>
> > On Oct 6, 2017, at 4:21 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >
> > I wrote:
> >> I thought of a better way, as attached.
> >
> > Pushed. Ben, could you confirm that the committed patch fixes your
> > original use-case? The 9.5 version of the patch is at
> >
> > https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=13d2ed921035f2d88adf87d796373e920bdd56ee
>
> Not quickly, to be honest. But the test case is not hard. If you can do this without crashing, I'm convinced you've fixed the problem as I've seen it:
>
>
> SELECT * FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding');
>
> CREATE TABLE public.foo(i int);
>
> insert into public.foo(i) values(1);
>
> CREATE OR REPLACE FUNCTION logical_replication_slot_lsn_delta(slot text) RETURNS pg_lsn AS
> $$
> BEGIN
> return location from pg_logical_slot_peek_changes(slot,null,1) limit 1;
> END
> $$ language plpgsql;
>
> select logical_replication_slot_lsn_delta('regression_slot');

Yep, that one's definitely fixed now.

Greetings,

Andres Freund