BUG #16928: pg_restore --clean/-c occurs ERROR for partitioned range table

The following bug has been logged on the website:

Bug reference: 16928
Logged by: hua
Email address: hulehua(at)zoho(dot)com
PostgreSQL version: 13.1
Operating system: CentOS 7 x86_64
Description:

Hello, below is my steps for reproducing it:

1. setup data environment

./bin/psql -p 5444 -d postgres -U postgres
psql (13.1)
Type "help" for help.

postgres=# \d
Did not find any relations.
postgres=# create table table_range(id serial, user_id int4, create_time
timestamp(0) unique) partition by range(create_time);
CREATE TABLE
postgres=# create table table_range_1 partition of table_range for values
from ('2020-01-01') to ('2020-12-31');
CREATE TABLE
postgres=# \d+
List of relations
Schema | Name | Type | Owner | Persistence |
Size | Description
--------+--------------------+-------------------+----------+-------------+------------+-------------
public | table_range | partitioned table | postgres | permanent |
0 bytes |
public | table_range_1 | table | postgres | permanent |
0 bytes |
public | table_range_id_seq | sequence | postgres | permanent |
8192 bytes |
(3 rows)

postgres=# \q

2. use pg_dump to dump the postgres database to file postgres.dmp

./bin/pg_dump -p 5444 -d postgres -U postgres -Fc -f postgres.dmp

3. use pg_restore to restore the dump file directly to the original
database, with -c parameter

./bin/pg_restore -p 5444 -d postgres -U postgres -c -e postgres.dmp
pg_restore: while PROCESSING TOC:
pg_restore: from TOC entry 2997; 2606 16413 CONSTRAINT table_range_1
table_range_1_create_time_key postgres
pg_restore: error: could not execute query: ERROR: cannot drop inherited
constraint "table_range_1_create_time_key" of relation "table_range_1"
Command was: ALTER TABLE ONLY public.table_range_1 DROP CONSTRAINT
table_range_1_create_time_key;

PS, I'm not familiar with database, especially for range table topic; and
not sure whether it's a bug or not. Sorry for your time if this scenario is
normal. And I made a temporary fix which looks work well.

src/bin/pg_dump/pg_dump.c

++ 16976 if (!tbinfo->ispartition)
++ 16977 {
16978 appendPQExpBuffer(delq, "ALTER %sTABLE ONLY %s ",
foreign,
16979
fmtQualifiedDumpable(tbinfo));
16980 appendPQExpBuffer(delq, "DROP CONSTRAINT %s;\n",
16981
fmtId(coninfo->dobj.name));
++ 16982 }

Thank you and sorry for disturbing,
Hua