[HACKERS] pg_dump does not handle indirectly-granted permissions properly

AFAICT, pg_dump has no notion that it needs to be careful about the order
in which permissions are granted.  I did

regression=# create user joe;
CREATE ROLE
regression=# create user bob;
CREATE ROLE
regression=# create user alice;
CREATE ROLE
regression=# \c - joe
You are now connected to database "regression" as user "joe".
regression=> create table joestable(f1 int);
CREATE TABLE
regression=> grant select on joestable to alice with grant option;
GRANT
regression=> \c - alice
You are now connected to database "regression" as user "alice".
regression=> grant select on joestable to bob;
GRANT

and then pg_dump'd that.  The ACL entry for joestable looks like this:

--
-- TOC entry 5642 (class 0 OID 0)
-- Dependencies: 606
-- Name: joestable; Type: ACL; Schema: public; Owner: joe
--

SET SESSION AUTHORIZATION alice;
GRANT SELECT ON TABLE joestable TO bob;
RESET SESSION AUTHORIZATION;
GRANT SELECT ON TABLE joestable TO alice WITH GRANT OPTION;

Unsurprisingly, that fails to restore:

db2=# SET SESSION AUTHORIZATION alice;
SET
db2=> GRANT SELECT ON TABLE joestable TO bob;
ERROR:  permission denied for relation joestable


I am not certain whether this is a newly introduced bug or not.
However, I tried it in 9.2-9.6, and all of them produce the
GRANTs in the right order:

GRANT SELECT ON TABLE joestable TO alice WITH GRANT OPTION;
SET SESSION AUTHORIZATION alice;
GRANT SELECT ON TABLE joestable TO bob;
RESET SESSION AUTHORIZATION;

That might be just chance, but my current bet is that Stephen
broke it sometime in the v10 cycle --- especially since we
haven't heard any complaints like this from the field.
        regards, tom lane