I wrote:
> Richard Guo <guofenglinux@gmail.com> writes:
>> Agreed. Do you think it would be helpful to add some assertions to
>> verify the plan type?
> I thought about that but didn't experiment with it. I wonder whether
> it'd just make the code more fragile. Still, it might be useful to
> verify that things are happening as we expect.
After sleeping on it, I elected to add the Asserts as suggested,
except in v12 where they'd have had to look different. That's
not strictly a matter of laziness: v12's next release will be its
last, and I've been burned often enough to become very hesitant
about pushing even slightly-questionable code into an EOL release.
Pushed with that change.
regards, tom lane