BUG #17718: Unexpected REVOKE ALL permissions in the backup script

The following bug has been logged on the website:

Bug reference: 17718
Logged by: Kirill Kravtsov
Email address: kravtsov(dot)k(at)gmail(dot)com
PostgreSQL version: 14.5
Operating system: Centos 7
Description:

Hello,
I’m facing an unexpected behaviour in pg_dump when used after issuing a
REASSIGN OWNED statement in the database. For the problem to appear, one
need to create an extension that creates database objects as a specific user
and then issue REASSIGN OWNED from that user to another. There are two
distinct problems that I observe when running pg_dump against that
database:
1) The extension-generated objects now emit REVOKE ALL ... FROM "user" where
user is the role that originally created the extension. This creates a
dependency that shouldn't exist since all the permissions are supposed to be
reassigned to a new user.
2) If the user is dropped, the statement now mentions the role OID instead
of role name.

Having those dependencies in the backup script breaks some of the automation
by generating statements that cause a non-zero exit code when restoring the
DB. I don't want to ignore the exit code in this scenario, and I don't have
an ability to exclude those objects from the backup, so I would appreciate
if someone could look into this.

How to reproduce:
# setup
psql << EOF
CREATE ROLE testuser;
CREATE ROLE testsuper SUPERUSER;
CREATE DATABASE db1 OWNER testuser TEMPLATE template0;
EOF

# creating an extension that creates system objects in the DB
psql -d db1 -c "SET ROLE testsuper; CREATE EXTENSION pg_buffercache"

# reassign owned from super to regular
psql -d db1 -c "REASSIGN OWNED BY testsuper TO testuser"

# observe references to the super still exist
pg_dump -d db1 | grep 'REVOKE ALL'

# display the OID of the super role
psql -c "SELECT oid FROM pg_roles where rolname = 'testsuper'"

# drop super role
psql -c "DROP ROLE testsuper"

# observe oid reference in the script
pg_dump -d db1 | grep 'REVOKE ALL'

# cleanup
psql << EOF
DROP DATABASE IF EXISTS db1;
DROP ROLE IF EXISTS testuser;
DROP ROLE IF EXISTS testsuper;
EOF

Sample output:
$ # setup
$ psql << EOF
> CREATE ROLE testuser;
> CREATE ROLE testsuper SUPERUSER;
> CREATE DATABASE db1 OWNER testuser TEMPLATE template0;
> EOF
CREATE ROLE
CREATE ROLE
CREATE DATABASE
$ # creating an extension that creates system objects in the DB
$ psql -d db1 -c "SET ROLE testsuper; CREATE EXTENSION pg_buffercache"
CREATE EXTENSION
$ # reassign owned from super to regular
$ psql -d db1 -c "REASSIGN OWNED BY testsuper TO testuser"
REASSIGN OWNED
$ # observe references to the super still exist
$ pg_dump -d db1 | grep 'REVOKE ALL'
REVOKE ALL ON FUNCTION public.pg_buffercache_pages() FROM testsuper;
REVOKE ALL ON FUNCTION public.pg_buffercache_pages() FROM pg_monitor;
REVOKE ALL ON TABLE public.pg_buffercache FROM testsuper;
$ # display the OID of the super role
$ psql -c "SELECT oid FROM pg_roles where rolname = 'testsuper'"
oid
--------
258313
(1 row)

$
$ # drop super role
$ psql -c "DROP ROLE testsuper"
DROP ROLE
$
$ # observe oid reference in the script
$ pg_dump -d db1 | grep 'REVOKE ALL'
REVOKE ALL ON FUNCTION public.pg_buffercache_pages() FROM "258313";
REVOKE ALL ON FUNCTION public.pg_buffercache_pages() FROM pg_monitor;
REVOKE ALL ON TABLE public.pg_buffercache FROM "258313";
$
$ # cleanup
$ psql << EOF
> DROP DATABASE IF EXISTS db1;
> DROP ROLE IF EXISTS testuser;
> DROP ROLE IF EXISTS testsuper;
> EOF
DROP DATABASE
DROP ROLE
NOTICE: role "testsuper" does not exist, skipping
DROP ROLE