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

Richard Guo <guofenglinux@gmail.com> writes:
> On Wed, Aug 30, 2023 at 7:42 PM Richard Guo <guofenglinux@gmail.com> wrote:
>> When we expand Var 'c1' from func(c1), we figure out that it comes from
>> subquery 's'.  When we recurse into subquery 's', we just build an
>> additional level of ParseState atop the current ParseState, which seems
>> not correct.  Shouldn't we climb up by the nesting depth first before we
>> build the additional level of ParseState?  Something like
>> ...

> Here is the patch.

Yeah, I think your diagnosis is correct.  The existing regression tests
reach this code path, but not with netlevelsup different from zero.
I noted from the code coverage report that the same is true of the
nearby RTE_CTE code path: that does have a loop to crawl up the pstate
stack, but it isn't getting iterated.  The attached improved patch
extends the test case so it also covers that.