The following bug has been logged on the website:
Bug reference: 15019
Logged by: Álvaro Herrera
Email address: alvherre@alvh.no-ip.org
PostgreSQL version: 10.1
Operating system: doesn't matter
Description:
After some discussion with Stephen Amell in pgsql-es-ayuda [1], we arrived
at the conclusion that what it currently does for grantors of default ACL is
not good. I'm not sure what would be a good behavior, however.
[1]
https://www.postgresql.org/message-id/e8923666-3b5f-1024-76a5-cf377f5493dc@inbox.lv