The following bug has been logged on the website:
Bug reference: 13649
Logged by: aaron chan
Email address: 450019844(at)qq(dot)com
PostgreSQL version: 9.5alpha2
Operating system: CentOS release 6.4 (Final)
Description:
step1:revoke "postgres" database user's superuser privilege.
step2:excute query "select relacl from pg_class where relname='pg_authid';"
the query result is "{postgres=arwdDxt/postgres}"
here it says "postgres" database user still has the update privilege ,but in
fact it can't.