Mark Dilger <hornschnorter(at)gmail(dot)com> writes:
> I have winnowed down the test a bit further. The attached
> smaller patch still triggers the same assertion as the prior
> patch did.
FWIW, I can reproduce the assertion failure with your first test,
but not with this simplified one.
I also confirm that it only happens in HEAD, not v12. I've not
actually bisected, but a look at the git history for predicate.c
sure makes it look like db2687d1f ("Optimize PredicateLockTuple")
must be to blame.
regards, tom lane