Assertion `grantee->counter > 0' failed in merge_role_privileges upon concurrent CREATE ROLE and FLUSH PRIVILEGES

--connect (con1,localhost,root,,test)

CREATE ROLE a;

FLUSH TABLES;

--connection default

--send

  CREATE ROLE b WITH ADMIN a;

--connection con1

FLUSH PRIVILEGES;

# Cleanup

--disconnect con1

--connection default

--reap

DROP ROLE a, b;

mysqld: /data/src/10.0/sql/sql_acl.cc:5364: int merge_role_privileges(ACL_ROLE*, ACL_ROLE*, void*): Assertion `grantee->counter > 0' failed.

181213 17:31:16 [ERROR] mysqld got signal 6 ;

#7  0x00007f631ba80ee2 in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6

#8  0x00000000005d17e4 in merge_role_privileges (role=0x7f63158cc4f0, grantee=0x7f63158cc3e0, context=0x7f631d8ea7a0) at /data/src/10.0/sql/sql_acl.cc:5364

#9  0x00000000005d0187 in traverse_role_graph_impl (user=0x7f63158cc4f0, context=0x7f631d8ea7a0, offset=88, on_node=0x0, on_edge=0x5d178b <merge_role_privileges(ACL_ROLE*, ACL_ROLE*, void*)>) at /data/src/10.0/sql/sql_acl.cc:4773

#10 0x00000000005d03de in traverse_role_graph_up (role=0x7f63158cc4f0, context=0x7f631d8ea7a0, on_node=0x0, on_edge=0x5d178b <merge_role_privileges(ACL_ROLE*, ACL_ROLE*, void*)>) at /data/src/10.0/sql/sql_acl.cc:4838

#11 0x00000000005d503a in propagate_role_grants_action (role_ptr=0x7f63158cc4f0, ptr=0x0) at /data/src/10.0/sql/sql_acl.cc:6568

#12 0x0000000000e065ee in my_hash_iterate (hash=0x17e7200 <acl_roles>, action=0x5d4f87 <propagate_role_grants_action(void*, void*)>, argument=0x0) at /data/src/10.0/mysys/hash.c:770

#13 0x00000000005d5846 in grant_reload (thd=0x7f6315aa8070) at /data/src/10.0/sql/sql_acl.cc:6651

#14 0x000000000079a188 in reload_acl_and_cache (thd=0x7f6315aa8070, options=1, tables=0x0, write_to_binlog=0x7f631d8ec27c) at /data/src/10.0/sql/sql_reload.cc:84

#15 0x0000000000652d7b in mysql_execute_command (thd=0x7f6315aa8070) at /data/src/10.0/sql/sql_parse.cc:4309

#16 0x00000000006589d0 in mysql_parse (thd=0x7f6315aa8070, rawbuf=0x7f6313c22088 "FLUSH PRIVILEGES", length=16, parser_state=0x7f631d8ec640) at /data/src/10.0/sql/sql_parse.cc:6637

#17 0x000000000064b2f0 in dispatch_command (command=COM_QUERY, thd=0x7f6315aa8070, packet=0x7f6316fea071 "FLUSH PRIVILEGES", packet_length=16) at /data/src/10.0/sql/sql_parse.cc:1300

#18 0x000000000064a5f0 in do_command (thd=0x7f6315aa8070) at /data/src/10.0/sql/sql_parse.cc:1003

#19 0x000000000076bf08 in do_handle_one_connection (thd_arg=0x7f6315aa8070) at /data/src/10.0/sql/sql_connect.cc:1377

#20 0x000000000076bc7a in handle_one_connection (arg=0x7f6315aa8070) at /data/src/10.0/sql/sql_connect.cc:1292

#21 0x0000000000acdb54 in pfs_spawn_thread (arg=0x7f63159a2870) at /data/src/10.0/storage/perfschema/pfs.cc:1861

#22 0x00007f631d569494 in start_thread (arg=0x7f631d8ed700) at pthread_create.c:333

#23 0x00007f631bb3d93f in clone () from /lib/x86_64-linux-gnu/libc.so.6