BUG #15482: Foreign keys to a partition (NOT A PARTITIONED) break the server

The following bug has been logged on the website:

Bug reference: 15482
Logged by: Gianluca Alberici
Email address: alberici(at)abinetworks(dot)biz
PostgreSQL version: 11.0
Operating system: Debian Stretch
Description:

That happens also for non circular refernces (ie other tables referring to a
partition)
If i have a partitioned table...

abi2=> \d+ _tmp_test_loop_ref_part
Table "phoebe._tmp_test_loop_ref_part"
Column | Type | Collation | Nullable | Default | Storage | Stats target
| Description
--------+----------+-----------+----------+---------+---------+--------------+-------------
id | integer | | not null | | plain |
|
refid | integer | | | | plain |
|
pi | smallint | | | 0 | plain |
|
Partition key: RANGE (pi)
Partitions: _tmp_test_loop_ref FOR VALUES FROM ('0') TO ('1')

and a partition on this table

abi2=> \d _tmp_test_loop_ref
Table "phoebe._tmp_test_loop_ref"
Column | Type | Collation | Nullable | Default
--------+----------+-----------+----------+---------
id | integer | | not null |
refid | integer | | |
pi | smallint | | | 0
Partition of: _tmp_test_loop_ref_part FOR VALUES FROM ('0') TO ('1')
Indexes:
"_tmp_test_loop_ref_pkey" PRIMARY KEY, btree (id)
Foreign-key constraints:
"fk_loop_ref" FOREIGN KEY (refid) REFERENCES _tmp_test_loop_ref(id) ON
UPDATE CASCADE ON DELETE RESTRICT
Referenced by:
TABLE "_tmp_test_loop_ref" CONSTRAINT "fk_loop_ref" FOREIGN KEY (refid)
REFERENCES _tmp_test_loop_ref(id) ON UPDATE CASCADE ON DELETE RESTRICT

is it normal that server break (segmentation fault, recovery mode and
restart !) if i

abi2=> begin;
BEGIN
abi2=> delete from _tmp_test_loop_ref where id=1;
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>

Heres the LOG:

2018-11-01 17:34:28.266 CET [10401] LOG: server process (PID 18213) was
terminated by signal 11: Segmentation fault
2018-11-01 17:34:28.266 CET [10401] DETAIL: Failed process was running:
delete from _tmp_test_loop_ref where id=1;
2018-11-01 17:34:28.266 CET [10401] LOG: terminating any other active
server processes
2018-11-01 17:34:28.266 CET [17927] WARNING: terminating connection because
of crash of another server process
2018-11-01 17:34:28.266 CET [17927] DETAIL: The postmaster has commanded
this server process to roll back the current transaction and exit, because
another server process exited abnormally and possibly corrupted shared
memory.
2018-11-01 17:34:28.266 CET [17927] HINT: In a moment you should be able to
reconnect to the database and repeat your command.
2018-11-01 17:34:28.267 CET [18241] phoebe(at)abi2 FATAL: the database system
is in recovery mode
2018-11-01 17:34:28.270 CET [10401] LOG: all server processes terminated;
reinitializing
2018-11-01 17:34:28.318 CET [18242] LOG: database system was interrupted;
last known up at 2018-11-01 17:27:13 CET
2018-11-01 17:34:28.491 CET [18242] LOG: database system was not properly
shut down; automatic recovery in progress
2018-11-01 17:34:28.507 CET [18242] LOG: redo starts at 1/E89B34B0
2018-11-01 17:34:28.507 CET [18242] LOG: invalid record length at
1/E89B3590: wanted 24, got 0
2018-11-01 17:34:28.507 CET [18242] LOG: redo done at 1/E89B3558
2018-11-01 17:34:28.595 CET [10401] LOG: database system is ready to accept
connections