Re: v16 regression - wrong query results with LEFT JOINs + join removal

I wrote:
> Yeah, I've just traced the problem to remove_rel_from_query() deciding
> that it can drop the qual of interest :-(.  I'd done this:
> -       if (RINFO_IS_PUSHED_DOWN(rinfo, joinrelids))
> +       if (bms_is_member(ojrelid, rinfo->required_relids))
> as part of an unfinished effort at getting rid of RestrictInfos'
> is_pushed_down flags, and this example shows that the replacement
> condition is faulty.

> What I'm inclined to do about it is just revert this particular
> change.  But I'd better run around and see where else I did that,
> because the idea is evidently not ready for prime time.

Looks like that was the only such change in 2489d76c4 or
follow-ons, so done, with a test case based on your example.

            regards, tom lane