Assertion `!expl_lock || expl_lock->trx == arg->impl_trx' failed in lock_rec_other_trx_holds_expl_callback upon concurrent UPDATE with unique blobs

--source include/have_innodb.inc

CREATE TABLE t1 (a INT, b TEXT UNIQUE) ENGINE=InnoDB;

INSERT INTO t1 () VALUES (),();

UPDATE IGNORE t1 SET b = '';

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

--let $conid= `SELECT CONNECTION_ID()`

--delimiter $

--send

LOOP

  UPDATE t1 SET a = 1;

END LOOP $

--delimiter ;

--connection default

UPDATE t1 SET b = NULL;

--error ER_DUP_ENTRY

INSERT INTO t1 VALUES (1,''),(1,'');

# Cleanup

--eval KILL $conid

DROP TABLE t1;

mysqld: /data/src/10.4/storage/innobase/lock/lock0lock.cc:5437: my_bool lock_rec_other_trx_holds_expl_callback(rw_trx_hash_element_t*, lock_rec_other_trx_holds_expl_arg*): Assertion `!expl_lock || expl_lock->trx == arg->impl_trx' failed.

200722 21:36:43 [ERROR] mysqld got signal 6 ;

#7  0x00007f8334780f12 in __GI___assert_fail (assertion=0x55e90b20bc30 "!expl_lock || expl_lock->trx == arg->impl_trx", file=0x55e90b209718 "/data/src/10.4/storage/innobase/lock/lock0lock.cc", line=5437, function=0x55e90b2102c0 <lock_rec_other_trx_holds_expl_callback(rw_trx_hash_element_t*, lock_rec_other_trx_holds_expl_arg*)::__PRETTY_FUNCTION__> "my_bool lock_rec_other_trx_holds_expl_callback(rw_trx_hash_element_t*, lock_rec_other_trx_holds_expl_arg*)") at assert.c:101

#8  0x000055e90a930752 in lock_rec_other_trx_holds_expl_callback (element=0x7f82dc06c170, arg=0x7f832db27350) at /data/src/10.4/storage/innobase/lock/lock0lock.cc:5437

#9  0x000055e90a9378b0 in rw_trx_hash_t::debug_iterator (element=0x7f82dc06c170, arg=0x7f832db27300) at /data/src/10.4/storage/innobase/include/trx0sys.h:535

#10 0x000055e90aed4f13 in l_find (head=0x55e90e743700, cs=0x0, hashnr=0, key=0x7f832db27300 "t\005\223\n\351U", keylen=0, cursor=0x7f832db272a0, pins=0x55e90e73b610, callback=0x55e90a937827 <rw_trx_hash_t::debug_iterator(rw_trx_hash_element_t*, rw_trx_hash_t::debug_iterator_arg*)>) at /data/src/10.4/mysys/lf_hash.c:127

#11 0x000055e90aed5c0b in lf_hash_iterate (hash=0x55e90babbfc0 <trx_sys+2496>, pins=0x55e90e73b610, action=0x55e90a937827 <rw_trx_hash_t::debug_iterator(rw_trx_hash_element_t*, rw_trx_hash_t::debug_iterator_arg*)>, argument=0x7f832db27300) at /data/src/10.4/mysys/lf_hash.c:519

#12 0x000055e90a937c9b in rw_trx_hash_t::iterate (this=0x55e90babbfc0 <trx_sys+2496>, caller_trx=0x7f832e5c2140, action=0x55e90a937827 <rw_trx_hash_t::debug_iterator(rw_trx_hash_element_t*, rw_trx_hash_t::debug_iterator_arg*)>, argument=0x7f832db27300) at /data/src/10.4/storage/innobase/include/trx0sys.h:753

#13 0x000055e90a9309c6 in lock_rec_other_trx_holds_expl (caller_trx=0x7f832e5c2140, trx=0x7f832e5c3268, rec=0x7f832e2f4096 "", block=0x7f832ddee620) at /data/src/10.4/storage/innobase/lock/lock0lock.cc:5483

#14 0x000055e90a930e3e in lock_rec_convert_impl_to_expl (caller_trx=0x7f832e5c2140, block=0x7f832ddee620, rec=0x7f832e2f4096 "", index=0x7f82dc148c40, offsets=0x7f832db277e0) at /data/src/10.4/storage/innobase/lock/lock0lock.cc:5549

#15 0x000055e90a931e85 in lock_sec_rec_read_check_and_lock (flags=0, block=0x7f832ddee620, rec=0x7f832e2f4096 "", index=0x7f82dc148c40, offsets=0x7f832db277e0, mode=LOCK_X, gap_mode=0, thr=0x7f82dc14b338) at /data/src/10.4/storage/innobase/lock/lock0lock.cc:5759

#16 0x000055e90aa653fb in sel_set_rec_lock (pcur=0x7f82dc14aac8, rec=0x7f832e2f4096 "", index=0x7f82dc148c40, offsets=0x7f832db277e0, mode=3, type=0, thr=0x7f82dc14b338, mtr=0x7f832db28040) at /data/src/10.4/storage/innobase/row/row0sel.cc:1279

#17 0x000055e90aa6fc35 in row_search_mvcc (buf=0x7f82dc147870 "\370\001", mode=PAGE_CUR_GE, prebuilt=0x7f82dc14a8f0, match_mode=1, direction=0) at /data/src/10.4/storage/innobase/row/row0sel.cc:5046

#18 0x000055e90a87eec8 in ha_innobase::index_read (this=0x7f82dc00ae38, buf=0x7f82dc147870 "\370\001", key_ptr=0x7f832db2873f "", key_len=9, find_flag=HA_READ_KEY_EXACT) at /data/src/10.4/storage/innobase/handler/ha_innodb.cc:9273

#19 0x000055e90a643a6c in handler::index_read_map (this=0x7f82dc00ae38, buf=0x7f82dc147870 "\370\001", key=0x7f832db2873f "", keypart_map=18446744073709551615, find_flag=HA_READ_KEY_EXACT) at /data/src/10.4/sql/handler.h:3627

#20 0x000055e90a633cba in handler::ha_index_read_map (this=0x7f82dc00ae38, buf=0x7f82dc147870 "\370\001", key=0x7f832db2873f "", keypart_map=18446744073709551615, find_flag=HA_READ_KEY_EXACT) at /data/src/10.4/sql/handler.cc:2919

#21 0x000055e90a63e549 in check_duplicate_long_entry_key (table=0x7f82dc149630, h=0x7f82dc00ae38, new_rec=0x7f82dc147870 "\370\001", key_no=0) at /data/src/10.4/sql/handler.cc:6588

#22 0x000055e90a63ec0e in check_duplicate_long_entries (table=0x7f82dc149630, h=0x7f82dc00ae38, new_rec=0x7f82dc147870 "\370\001") at /data/src/10.4/sql/handler.cc:6658

#23 0x000055e90a63ef58 in handler::ha_write_row (this=0x7f82dc00ae38, buf=0x7f82dc147870 "\370\001") at /data/src/10.4/sql/handler.cc:6739

#24 0x000055e90a28cca1 in write_record (thd=0x7f82dc000af0, table=0x7f82dc149630, info=0x7f832db28a90) at /data/src/10.4/sql/sql_insert.cc:2060

#25 0x000055e90a289bf1 in mysql_insert (thd=0x7f82dc000af0, table_list=0x7f82dc013290, fields=..., values_list=..., update_fields=..., update_values=..., duplic=DUP_ERROR, ignore=false) at /data/src/10.4/sql/sql_insert.cc:1078

#26 0x000055e90a2d6f51 in mysql_execute_command (thd=0x7f82dc000af0) at /data/src/10.4/sql/sql_parse.cc:4518

#27 0x000055e90a2e289b in mysql_parse (thd=0x7f82dc000af0, rawbuf=0x7f82dc013198 "INSERT INTO t1 VALUES (1,''),(1,'')", length=35, parser_state=0x7f832db29570, is_com_multi=false, is_next_command=false) at /data/src/10.4/sql/sql_parse.cc:7895

#28 0x000055e90a2cedd0 in dispatch_command (command=COM_QUERY, thd=0x7f82dc000af0, packet=0x7f82dc156cd1 "INSERT INTO t1 VALUES (1,''),(1,'')", packet_length=35, is_com_multi=false, is_next_command=false) at /data/src/10.4/sql/sql_parse.cc:1834

#29 0x000055e90a2cd572 in do_command (thd=0x7f82dc000af0) at /data/src/10.4/sql/sql_parse.cc:1352

#30 0x000055e90a45662e in do_handle_one_connection (connect=0x55e90e83b580) at /data/src/10.4/sql/sql_connect.cc:1412

#31 0x000055e90a45637d in handle_one_connection (arg=0x55e90e83b580) at /data/src/10.4/sql/sql_connect.cc:1316

#32 0x000055e90ae569bb in pfs_spawn_thread (arg=0x55e90e7b9530) at /data/src/10.4/storage/perfschema/pfs.cc:1869

#33 0x00007f83367094a4 in start_thread (arg=0x7f832db2a700) at pthread_create.c:456

#34 0x00007f833483dd0f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97