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(parent: 43af714) | patch

Defend against bogus parameterization of join input paths.

Defend against bogus parameterization of join input paths.

An outer join cannot be formed using an input path that is parameterized
by a value that is supposed to be nulled by the outer join. This is
obviously nonsensical, and it could lead to a bad plan being selected;
although currently it seems that we'll hit various sanity-check
assertions first.

I think that such cases were formerly prevented by the delay_upper_joins
mechanism, but now that that's gone we need an explicit check.

(Perhaps we should avoid generating baserel paths that could
lead to this situation in the first place; but it seems like
having a defense at the join level would be a good idea anyway.)

Richard Guo and Tom Lane, per report from Jaime Casanova

Discussion: https://postgr.es/m/CAJKUy5g2uZRrUDZJ8p-=giwcSHVUn0c9nmdxPSY0jF0Ov8VoEA@mail.gmail.com

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