jian he <jian(dot)universality(at)gmail(dot)com> writes:
> select cast(NULL::text as unknown);
> ERROR: failed to find conversion function from unknown to text
Is there a good reason why that shouldn't be an error?
I certainly don't like the cast pathway you suggest adding
to make it not be one --- that seems likely to cause lots of
not-very-desirable behaviors.
regards, tom lane