Re: Test instability when pg_dump orders by OID

On Fri, Aug 22, 2025 at 10:20:19PM -0700, Noah Misch wrote:
> On Mon, Aug 11, 2025 at 12:20:09AM +0500, Kirill Reshke wrote:
> > On Sun, 10 Aug 2025 at 21:37, Noah Misch <noah(at)leadboat(dot)com> wrote:
> > > Thanks. Could you make src/test/regress create regression database objects so
> > > the code addition has coverage? Using pg_signal_backend and
> > > pg_read_all_settings as the default ACL role names should avoid that suite's
> > > limitations. (The suite must run under any role name and must drop any roles
> > > it creates, so it can't assume any particular non-system role name survives
> > > the suite.)
> >
> > Here is my attempt at implementing necessary legwork. It's v3 because
> > I accidentally cleared the CC list in my previous attempt. Noah kindly
> > explained to me how additions to the regress test will cause pg_dump
> > logic to be tested as well.
> > TIL 002_pg_upgarde.pl runs a regression suite, so if we create any
> > database objects in it, it will end up being dumped and restored in
> > that test.
> > So, I checked that without changes in pg_dump_sort.c, 002_pg_upgarde
> > fails and with changes it does not.
>
> Great.
>
> > PFA. I am not horribly sure about my additions to the
> > `src/test/regress/sql/privileges.sql` file, maybe appending SQL to the
> > end of the file is not the best option and there is a better place.
>
> I like how src/test/regress/sql/collate.icu.utf8.sql puts that kind of thing
> just after cleanup, so I put it there. Pushed as b61a5c4 with a few other
> cosmetic changes. Thanks.

TestUpgradeXversion fails:
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=copperhead&dt=2025-08-23%2007%3A34%3A38

--- /home/pgbf/buildroot/upgrade.copperhead/REL_18_STABLE/origin-REL_16_STABLE.sql.fixed 2025-08-23 10:28:16.464887433 +0200
+++ /home/pgbf/buildroot/upgrade.copperhead/REL_18_STABLE/converted-REL_16_STABLE-to-REL_18_STABLE.sql.fixed 2025-08-23 10:28:16.508887289 +0200
@@ -606490,13 +606490,13 @@
--
-- Name: DEFAULT PRIVILEGES FOR TABLES; Type: DEFAULT ACL; Schema: -; Owner: pg_read_all_settings
--
-ALTER DEFAULT PRIVILEGES FOR ROLE pg_read_all_settings REVOKE SELECT,INSERT,REFERENCES,DELETE,TRIGGER,TRUNCATE,UPDATE ON TABLES FROM pg_read_all_settings;
-ALTER DEFAULT PRIVILEGES FOR ROLE pg_read_all_settings GRANT SELECT,REFERENCES,DELETE,TRIGGER,TRUNCATE,UPDATE ON TABLES TO pg_read_all_settings;
+ALTER DEFAULT PRIVILEGES FOR ROLE pg_read_all_settings REVOKE ALL ON TABLES FROM pg_read_all_settings;
+ALTER DEFAULT PRIVILEGES FOR ROLE pg_read_all_settings GRANT SELECT,REFERENCES,DELETE,TRIGGER,TRUNCATE,MAINTAIN,UPDATE ON TABLES TO pg_read_all_settings;

Crossing the boundary of the MAINTAIN privilege existing seems relevant. Will
fix. (My checklist did tell me to do a local run of TestUpgradeXversion. I
skipped it, betting this patch wouldn't break that test. I lost that bet.)