Further tighten nullingrel marking rules in build_joinrel_tlist().
The code I added in
fee7b77b9 could misbehave if commute_above_r
contains multiple relids. While adding too many relids here is
probably harmless (pre-
fee7b77b9, we did it all the time), it's
not very expensive to be accurate: we just have to intersect
commute_above_r with the join's relids.
Discussion: https://postgr.es/m/17781-
c0405c8b3cd5e072@postgresql.org