Re: Missing warning on revokes with grant options

Sorry for the multiple consecutive emails. I just came across this
comment that explains the current behavior in restrict_and_check_grant

/*
* Restrict the operation to what we can actually grant or revoke, and
* issue a warning if appropriate.  (For REVOKE this isn't quite what the
* spec says to do: the spec seems to want a warning only if no privilege
* bits actually change in the ACL. In practice that behavior seems much
* too noisy, as well as inconsistent with the GRANT case.)
*/

However, I still think the current behavior is a bit strange since
holding a grant option is not directly required to issue a revoke.
Perhaps for revoke the logic should be:
  - for each specified privilege:
      - if the set of acl items on the specified object that includes
        this privilege is non empty
      - and none of those acl items have the current role as the
        grantor
      - then issue a warning.

Thanks,
Joe Koshakow