Re: Missing compiled default for channel_binding param from PQconndefaults

Daniele Varrazzo <daniele(dot)varrazzo(at)gmail(dot)com> writes:
> compiled is expected to be "prefer" or "disable" as per docs.
> Please find a patch attached.

Yeah, that does look inconsistent, and I don't object to fixing
it. But it's already the case that not all connection parameters
have defaults in that struct. Isn't there a psycopg3 bug here
too, that it's not coping with a null default sanely?

I'm a bit suspicious that psycopg3 is expecting that NULL and
empty-string are equivalent for all parameters. That is a convention
we upheld for a long time, but recent parameters have gotten away
from that --- not only channel_binding, but others such as sslmode.
If that's the underlying cause here then we need to think about
whether we want to restore that expectation.

regards, tom lane