Right now, pg_service.conf returns "syntax error" if it encounters a parameter it doesn't know about.
This seems user-unfriendly, both in the error message (because it really isn't a syntax error) and in the behaviour itself (because it doesn't work when sometimes it should).
For example, if I have a service file with gssencmode=disable set, that service file cannot be used by a psql client linked against libpq from version 10. Even if the behavior would be identical (since v10 doesn't have gssencmode).
Is there a particular reason we (1) refuse unknown parameters in the file, and (2) call it a "syntax error"?
The documentation just says it's "INI format" file -- though in my experience most other INI file parsers just ignore extra parameters included..
//Magnus
