SUBSCRIPTION command hangs up, segfault occurs in the server process and to cancel the execution.

Hi.
While verifying the logical replication of PostgreSQL 10-devel, I found the
following problem.

* When you run the SUBSCRIPTION command against a table in the same
PostgreSQL server, hang up.
* Canceling the hung SUBSCRIPTION command with CTRL + C causes a server
process occurs Segfault, and the PostgreSQL server to restart.

--------
[Steps to Reproduce]

$ createdb db1 -U postgres
$ createdb db2 -U postgres
$ psql -U postgres db1 -c "CREATE TABLE test (id int primary key, data
text)"
$ psql -U postgres db2 -c "CREATE TABLE test (id int primary key, data
text)"
$ psql -U postgres db1 -c "CREATE PUBLICATION pub_db1_test FOR TABLE test"
$ psql -U postgres db2 -c "CREATE SUBSCRIPTION sub_db2_test CONNECTION
'dbname=db1 port=5432 user=postgres' PUBLICATION pub_db1_test"

The SUBSCRIPTION command does not end, it hangs up.
At this time, the following logs are output in the server log.

2017-02-21 06:58:05.082 JST [22060] LOG: logical decoding found initial
starting point at 0/1C06660
2017-02-21 06:58:05.082 JST [22060] DETAIL: 1 transaction needs to finish.

Suspending psql (running SUBSCRIPTION) with CTRL + C causes a Segfault in
the server process.
At this time, the following message is output to the server log.

2017-02-21 07:01:00.246 JST [22059] ERROR: canceling statement due to user
request
2017-02-21 07:01:00.246 JST [22059] STATEMENT: CREATE SUBSCRIPTION
sub_db2_test CONNECTION 'dbname=db1 port=5432 user=postgres' PUBLICATION
pub_db1_test
2017-02-21 07:01:01.006 JST [21445] LOG: server process (PID 22060) was
terminated by signal 11: Segmentation fault
2017-02-21 07:01:01.007 JST [21445] LOG: terminating any other active
server processes

--------
[Environment]

postgres=# SELECT version();
version

------------------------------------------------------------------------------------------------------------
PostgreSQL 10devel on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.2
20140120 (Red Hat 4.8.2-16), 64-bit
(1 row)

postgres=# SHOW wal_level;
wal_level
-----------
logical
(1 row)

postgres=# SHOW max_wal_senders;;
max_wal_senders
-----------------
10
(1 row)

postgres=# SHOW max_replication_slots;
max_replication_slots
-----------------------
10
(1 row)

postgres=# TABLE pg_hba_file_rules ;
line_number | type | database | user_name | address |
netmask | auth_method | options | error
-------------+-------+---------------+------------+-----------+-----------------------------------------+-------------+---------+-------
2 | local | {all} | {all} | |
| trust | |
4 | host | {all} | {all} | 127.0.0.1 |
255.255.255.255 | trust | |
6 | host | {all} | {all} | ::1 |
ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff | trust | |
9 | local | {replication} | {postgres} | |
| trust | |
(4 rows)

Regards.