Steps to reproduce

See madelson/DistributedLock#174. Essentially, use the DistributedLock.Postgres package and then upgrade to Npgsql 8.

The issue

We are issuing a command like this:

SET LOCAL statement_timeout = 0;
SET LOCAL lock_timeout = 0;

SELECT pg_catalog.pg_advisory_lock(@key) AS result

Retrieving the result with ExecuteScalarAsync(). Previously this would return DBNull.Value when pg_advisory_lock returned null, but as of 8.0 it seems to return DBNull.Value instead.

My brief scan of the breaking change documentation didn't turn up anything about this, so I decided to report. Apologies if I missed it!

Further technical details

Npgsql version: 8.0.0