Assertion `field_length < 5' failed in Field_year::val_str or data corruption upon SELECT with UNION and aggregate functions

CREATE TABLE t1 (f YEAR);

INSERT IGNORE INTO t1 VALUES (1971),(1972);

SELECT MAX( NULLIF( f, '1900' ) ) AS f FROM t1 UNION SELECT MAX( NULLIF( f, '1900' ) ) AS f FROM t1;

# Cleanup

DROP TABLE t1;

mysqld: /data/src/10.1/sql/field.cc:6276: virtual String* Field_year::val_str(String*, String*): Assertion `field_length < 5' failed.

181031 17:43:14 [ERROR] mysqld got signal 6 ;

#7  0x00007f11a7d5fee2 in __assert_fail () from /lib/x86_64-linux-gnu/libc.so.6

#8  0x0000558470fe80ff in Field_year::val_str (this=0x7f1190173328, val_buffer=0x7f11a2039420, val_ptr=0x7f11a2039420) at /data/src/10.2-bug/sql/field.cc:6325

#9  0x0000558470ccba07 in Field::val_str (this=0x7f1190173328, str=0x7f11a2039420) at /data/src/10.2-bug/sql/field.h:865

#10 0x0000558470cc9e59 in Protocol_text::store (this=0x7f11900010b8, field=0x7f1190173328) at /data/src/10.2-bug/sql/protocol.cc:1245

#11 0x000055847102e621 in Item_field::send (this=0x7f1190015a40, protocol=0x7f11900010b8, buffer=0x7f11a20397c0) at /data/src/10.2-bug/sql/item.cc:7149

#12 0x0000558470cc8f34 in Protocol::send_result_set_row (this=0x7f11900010b8, row_items=0x7f1190004d70) at /data/src/10.2-bug/sql/protocol.cc:979

#13 0x0000558470d4ab36 in select_send::send_data (this=0x7f1190014550, items=...) at /data/src/10.2-bug/sql/sql_class.cc:2703

#14 0x0000558470e04c4c in end_send (join=0x7f119015f960, join_tab=0x7f1190160ca8, end_of_records=false) at /data/src/10.2-bug/sql/sql_select.cc:19902

#15 0x0000558470e02728 in evaluate_join_record (join=0x7f119015f960, join_tab=0x7f11901608f8, error=0) at /data/src/10.2-bug/sql/sql_select.cc:18954

#16 0x0000558470e02032 in sub_select (join=0x7f119015f960, join_tab=0x7f11901608f8, end_of_records=false) at /data/src/10.2-bug/sql/sql_select.cc:18734

#17 0x0000558470e015cb in do_select (join=0x7f119015f960, procedure=0x0) at /data/src/10.2-bug/sql/sql_select.cc:18278

#18 0x0000558470ddbbbb in JOIN::exec_inner (this=0x7f119015f960) at /data/src/10.2-bug/sql/sql_select.cc:3601

#19 0x0000558470ddb068 in JOIN::exec (this=0x7f119015f960) at /data/src/10.2-bug/sql/sql_select.cc:3396

#20 0x0000558470ddc233 in mysql_select (thd=0x7f1190000b00, tables=0x7f1190004730, wild_num=0, fields=..., conds=0x0, og_num=0, order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=268435456, result=0x7f1190014550, unit=0x7f11900046e0, select_lex=0x7f1190013518) at /data/src/10.2-bug/sql/sql_select.cc:3796

#21 0x0000558470e7bcd3 in st_select_lex_unit::exec (this=0x7f11900046e0) at /data/src/10.2-bug/sql/sql_union.cc:1161

#22 0x0000558470e77ed6 in mysql_union (thd=0x7f1190000b00, lex=0x7f1190004618, result=0x7f1190014550, unit=0x7f11900046e0, setup_tables_done_option=0) at /data/src/10.2-bug/sql/sql_union.cc:41

#23 0x0000558470dd0453 in handle_select (thd=0x7f1190000b00, lex=0x7f1190004618, result=0x7f1190014550, setup_tables_done_option=0) at /data/src/10.2-bug/sql/sql_select.cc:354

#24 0x0000558470d9bc87 in execute_sqlcom_select (thd=0x7f1190000b00, all_tables=0x7f1190012b00) at /data/src/10.2-bug/sql/sql_parse.cc:6477

#26 0x0000558470d9faec in mysql_parse (thd=0x7f1190000b00, rawbuf=0x7f1190012488 "SELECT MAX( NULLIF( f, '1900' ) ) AS f FROM t1 UNION SELECT MAX( NULLIF( f, '1900' ) ) AS f FROM t1", length=99, parser_state=0x7f11a203b200, is_com_multi=false, is_next_command=false) at /data/src/10.2-bug/sql/sql_parse.cc:8009

#27 0x0000558470d8d56a in dispatch_command (command=COM_QUERY, thd=0x7f1190000b00, packet=0x7f119008ca41 "", packet_length=99, is_com_multi=false, is_next_command=false) at /data/src/10.2-bug/sql/sql_parse.cc:1824

#28 0x0000558470d8becd in do_command (thd=0x7f1190000b00) at /data/src/10.2-bug/sql/sql_parse.cc:1378

#29 0x0000558470edd6a6 in do_handle_one_connection (connect=0x5584733123e0) at /data/src/10.2-bug/sql/sql_connect.cc:1335

#30 0x0000558470edd433 in handle_one_connection (arg=0x5584733123e0) at /data/src/10.2-bug/sql/sql_connect.cc:1241

#31 0x00005584712ffa50 in pfs_spawn_thread (arg=0x5584732f4fe0) at /data/src/10.2-bug/storage/perfschema/pfs.cc:1862

#32 0x00007f11a9a36494 in start_thread (arg=0x7f11a203c700) at pthread_create.c:333

#33 0x00007f11a7e1c93f in clone () from /lib/x86_64-linux-gnu/libc.so.6

SELECT MAX( NULLIF( f, '1900' ) ) AS f FROM t1 UNION SELECT MAX( NULLIF( f, '1900' ) ) AS f FROM t1;

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