Re: BUG #18077: PostgreSQL server subprocess crashed by a SELECT statement with WITH clause

On Tue, Sep 5, 2023 at 10:04 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Richard Guo <guofenglinux(at)gmail(dot)com> writes:
> > BTW, do you think get_name_for_var_field() has similar problem for
> > RTE_SUBQUERY case? The RTE_CTE code path in that function crawls up the
> > namespace stack before recursing into the CTE while the RTE_SUBQUERY
> > code patch does not, which looks like an oversight.
>
> Hmm, seems suspicious ...
>
> > I tried to find a
> > test case to show it's indeed a problem but with no luck.
>
> Note that any test case here would be of the form "dump a view
> or rule definition", not "EXPLAIN". What did you try?

Ah, thanks. I got one of the form "dump a view" leveraging your test
case from the v2 patch (with a minor tweak).

create view composite_v as
with cte(c) as materialized (select row(1, 2)),
cte2(c) as (select * from cte)
select 1 from cte2 as t
where (select * from (select c as c1) s
where (select (c1).f1 > 0)) is not null;

select pg_get_viewdef('composite_v', true);
ERROR: bogus varno: 1

So it is indeed a problem!

Here is v3 patch which is v2 + fix for this issue.

Thanks
Richard