Server crashes in TABLE::evaluate_update_default_function upon UPDATE on temporary table

CREATE TEMPORARY TABLE t1 (a DATETIME ON UPDATE CURRENT_TIMESTAMP);

ALTER TABLE t1 ADD b INT;

INSERT INTO t1 (b) VALUES (1),(2);

--error ER_BAD_FIELD_ERROR

ALTER TABLE t1 CHANGE COLUMN x xx INT;

UPDATE t1 SET b = 3;

#3  <signal handler called>

#4  0x00005645cfe7caa7 in TABLE::evaluate_update_default_function (this=0x7f1da81a8920) at /data/src/server-src/sql/table.cc:8463

#5  0x00005645cfcac688 in fill_record (thd=0x7f1da8000d50, table_arg=0x7f1da81a8920, fields=..., values=..., ignore_errors=false, update=true) at /data/src/server-src/sql/sql_base.cc:8509

#6  0x00005645cfcacbbe in fill_record_n_invoke_before_triggers (thd=0x7f1da8000d50, table=0x7f1da81a8920, fields=..., values=..., ignore_errors=false, event=TRG_EVENT_UPDATE) at /data/src/server-src/sql/sql_base.cc:8647

#7  0x00005645cfe52d32 in mysql_update (thd=0x7f1da8000d50, table_list=0x7f1da80134d0, fields=..., values=..., conds=0x0, order_num=0, order=0x0, limit=18446744073709551615, ignore=false, found_return=0x7f1db8ca9820, updated_return=0x7f1db8ca98e0) at /data/src/server-src/sql/sql_update.cc:990

#8  0x00005645cfd437dc in mysql_execute_command (thd=0x7f1da8000d50) at /data/src/server-src/sql/sql_parse.cc:4370

#9  0x00005645cfd50781 in mysql_parse (thd=0x7f1da8000d50, rawbuf=0x7f1da80133f8 "UPDATE t1 SET b = 3", length=19, parser_state=0x7f1db8caa140, is_com_multi=false, is_next_command=false) at /data/src/server-src/sql/sql_parse.cc:7901

#10 0x00005645cfd3b953 in dispatch_command (command=COM_QUERY, thd=0x7f1da8000d50, packet=0x7f1da8008751 "UPDATE t1 SET b = 3", packet_length=19, is_com_multi=false, is_next_command=false) at /data/src/server-src/sql/sql_parse.cc:1841

#11 0x00005645cfd39fdf in do_command (thd=0x7f1da8000d50) at /data/src/server-src/sql/sql_parse.cc:1359

#12 0x00005645cfec2c25 in do_handle_one_connection (connect=0x5645d2a6ddb0) at /data/src/server-src/sql/sql_connect.cc:1412

#13 0x00005645cfec2974 in handle_one_connection (arg=0x5645d2a6ddb0) at /data/src/server-src/sql/sql_connect.cc:1316

#14 0x00005645d08ca484 in pfs_spawn_thread (arg=0x5645d29b1130) at /data/src/server-src/storage/perfschema/pfs.cc:1869

#15 0x00007f1dc01686db in start_thread (arg=0x7f1db8cab700) at pthread_create.c:463

#16 0x00007f1dbebf688f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95