Re: BUG #18405: flaw in dump of inherited/dropped constraints

> thanks to Alvaro's work to treat NOT NULL the same way we've long
> treated more general CHECK constraints.  So there's no need to do
> anything in v17, and I think changing the behavior in released
> branches would draw more complaints than plaudits.  (Also, if pg_dump
> did try harder to duplicate this situation, the result would likely be
> that the dump would fail to load into v17+.)

I'd call that an acceptable resolution. My main concern is dump/restore not being able to dump & restore an existing
database,and this v17 change fixes this case. (For background, this odd inheritance wasn't a deliberate design, it was
a(supposedly temporary) workaround for a client bug.) 

>> ... So it looks like prior to 16, plain dumps had this
>> problem, but custom format dumps did not.
>
> Given the way pg_dump works, that's pretty hard to believe: you
> should get bitwise the same result from pg_dump to text versus
> pg_dump -Fc | pg_restore.  Can you provide a self-contained test
> showing a case where it doesn't?

I will re-run tests when I get a bit of time--it is possible I confused versions or schemas somewhere along the line of
switchingback and forth.