Comment 9 for bug 615157

I think there is a problem with your patch.
It removes "authreg.pgsql.sql.checkpassword" configuration option support (setting the query for ctx->sql_check_password).
It always uses _ar_pgsql_get_password() method.

This breaks the use case, when one defines the hashing function in query and uses DB to hash the provided password for comparison. (like "SELECT login FROM user WHERE login = '%s' AND password = MD5(%s) AND domain = '%s'")
There are people using this option (though it is undocumented in sm.xml) and we cannot remove its support.