> var noActionsPriv = { resource:

{ db: "", collection: "" }

, actions: [] };

> db.runCommand(

{ grantPrivilegesToRole: "roleName", privileges: [ noActionsPriv ] }

);
> db.runCommand(

{ revokePrivilegesFromRole: "roleName", privileges: [ noActionsPriv ] }

);

This is a bug for the sake of consistency with other privilege-related commands. For example, the createRole() command will fail if you pass in a privilege with an empty 'actions' array. These commands require at least one specified action in order to succeed.