Assertion `templ->mysql_null_bit_mask' failed in row_sel_store_mysql_rec upon modifying indexed column into blob

--source include/have_innodb.inc

CREATE TABLE t1 (t TIME, KEY(t)) ENGINE=InnoDB;

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

ALTER IGNORE TABLE t1 MODIFY t TEXT NOT NULL DEFAULT '';

# Cleanup

DROP TABLE t1;

mysqld: /data/src/10.4/storage/innobase/row/row0sel.cc:3061: bool row_sel_store_mysql_rec(byte*, row_prebuilt_t*, const rec_t*, const dtuple_t*, bool, const dict_index_t*, const ulint*): Assertion `templ->mysql_null_bit_mask' failed.

190224 22:02:23 [ERROR] mysqld got signal 6 ;

#7  0x00007fdcdb409ee2 in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6

#8  0x000056259c962361 in row_sel_store_mysql_rec (mysql_rec=0x7fdc8c06bf48 "", prebuilt=0x7fdc8c072498, rec=0x7fdcd4f1007e "", vrow=0x0, rec_clust=true, index=0x7fdc8c070358, offsets=0x7fdcd472e010) at /data/src/10.4/storage/innobase/row/row0sel.cc:3061

#9  0x000056259c9684ca in row_search_mvcc (buf=0x7fdc8c06bf48 "", mode=PAGE_CUR_GE, prebuilt=0x7fdc8c072498, match_mode=1, direction=0) at /data/src/10.4/storage/innobase/row/row0sel.cc:5441

#10 0x000056259c7c5d77 in ha_innobase::index_read (this=0x7fdc8c06b418, buf=0x7fdc8c06bf48 "", key_ptr=0x7fdcd472ea60 "\001", key_len=8, find_flag=HA_READ_KEY_EXACT) at /data/src/10.4/storage/innobase/handler/ha_innodb.cc:9314

#11 0x000056259c48eeb2 in handler::index_read_map (this=0x7fdc8c06b418, buf=0x7fdc8c06bf48 "", key=0x7fdcd472ea60 "\001", keypart_map=18446744073709551615, find_flag=HA_READ_KEY_EXACT) at /data/src/10.4/sql/handler.h:3594

#12 0x000056259c480f9c in handler::ha_index_read_map (this=0x7fdc8c06b418, buf=0x7fdc8c06bf48 "", key=0x7fdcd472ea60 "\001", keypart_map=18446744073709551615, find_flag=HA_READ_KEY_EXACT) at /data/src/10.4/sql/handler.cc:3039

#13 0x000056259c48a1cd in check_duplicate_long_entry_key (table=0x7fdc8c06c0b0, h=0x7fdc8c06b418, new_rec=0x7fdc8c06cf20 "", key_no=0) at /data/src/10.4/sql/handler.cc:6516

#14 0x000056259c48a750 in check_duplicate_long_entries (table=0x7fdc8c06c0b0, h=0x7fdc8c06b418, new_rec=0x7fdc8c06cf20 "") at /data/src/10.4/sql/handler.cc:6583

#15 0x000056259c48aa27 in handler::ha_write_row (this=0x7fdc8c06b418, buf=0x7fdc8c06cf20 "") at /data/src/10.4/sql/handler.cc:6660

#16 0x000056259c224bfc in copy_data_between_tables (thd=0x7fdc8c000b00, from=0x7fdc8c1500a0, to=0x7fdc8c06c0b0, create=..., ignore=true, order_num=0, order=0x0, copied=0x7fdcd472f800, deleted=0x7fdcd472f808, keys_onoff=Alter_info::LEAVE_AS_IS, alter_ctx=0x7fdcd47300e0) at /data/src/10.4/sql/sql_table.cc:10644

#17 0x000056259c222ba1 in mysql_alter_table (thd=0x7fdc8c000b00, new_db=0x7fdc8c005290, new_name=0x7fdc8c005690, create_info=0x7fdcd4730cd0, table_list=0x7fdc8c0155c0, alter_info=0x7fdcd4730c10, order_num=0, order=0x0, ignore=true) at /data/src/10.4/sql/sql_table.cc:10073

#18 0x000056259c2b0922 in Sql_cmd_alter_table::execute (this=0x7fdc8c015e50, thd=0x7fdc8c000b00) at /data/src/10.4/sql/sql_alter.cc:499

#19 0x000056259c141aca in mysql_execute_command (thd=0x7fdc8c000b00) at /data/src/10.4/sql/sql_parse.cc:6346

#20 0x000056259c146c72 in mysql_parse (thd=0x7fdc8c000b00, rawbuf=0x7fdc8c0154a8 "ALTER IGNORE TABLE t1 MODIFY t TEXT NOT NULL DEFAULT ''", length=55, parser_state=0x7fdcd4732180, is_com_multi=false, is_next_command=false) at /data/src/10.4/sql/sql_parse.cc:8157

#21 0x000056259c132360 in dispatch_command (command=COM_QUERY, thd=0x7fdc8c000b00, packet=0x7fdc8c13a181 "ALTER IGNORE TABLE t1 MODIFY t TEXT NOT NULL DEFAULT ''", packet_length=55, is_com_multi=false, is_next_command=false) at /data/src/10.4/sql/sql_parse.cc:1829

#22 0x000056259c130b34 in do_command (thd=0x7fdc8c000b00) at /data/src/10.4/sql/sql_parse.cc:1358

#23 0x000056259c2aa837 in do_handle_one_connection (connect=0x5625a048fd10) at /data/src/10.4/sql/sql_connect.cc:1399

#24 0x000056259c2aa5a8 in handle_one_connection (arg=0x5625a048fd10) at /data/src/10.4/sql/sql_connect.cc:1302

#25 0x000056259c7a1979 in pfs_spawn_thread (arg=0x5625a04d5b80) at /data/src/10.4/storage/perfschema/pfs.cc:1862

#26 0x00007fdcdd0e0494 in start_thread (arg=0x7fdcd4733700) at pthread_create.c:333

#27 0x00007fdcdb4c693f in clone () from /lib/x86_64-linux-gnu/libc.so.6