TABLE::prune_range_rowid_filters: Conditional jump or move depends on uninitialised value

CREATE TABLE t1 (pk INT, i INT, PRIMARY KEY (pk), KEY (pk,i)) ENGINE=MyISAM;

INSERT INTO t1 VALUES (1,10),(2,20);

SELECT * FROM t1 WHERE pk < 5;

# Cleanup

DROP TABLE t1;

==9761== Thread 6:

==9761== Conditional jump or move depends on uninitialised value(s)

==9761==    at 0xAC3669: TABLE::prune_range_rowid_filters() (rowid_filter.cc:252)

==9761==    by 0xAC3ABD: TABLE::init_cost_info_for_usable_range_rowid_filters(THD*) (rowid_filter.cc:403)

==9761==    by 0x8DCDC8: make_join_statistics(JOIN*, List<TABLE_LIST>&, st_dynamic_array*) (sql_select.cc:5286)

==9761==    by 0x8D1724: JOIN::optimize_inner() (sql_select.cc:2109)

==9761==    by 0x8CF441: JOIN::optimize() (sql_select.cc:1513)

==9761==    by 0x8DA129: mysql_select(THD*, TABLE_LIST*, unsigned int, List<Item>&, Item*, unsigned int, st_order*, st_order*, Item*, st_order*, unsigned long long, select_result*, st_select_lex_unit*, st_select_lex*) (sql_select.cc:4489)

==9761==    by 0x8CADAF: handle_select(THD*, LEX*, select_result*, unsigned long) (sql_select.cc:428)

==9761==    by 0x893882: execute_sqlcom_select(THD*, TABLE_LIST*) (sql_parse.cc:6588)

==9761==    by 0x888A27: mysql_execute_command(THD*) (sql_parse.cc:3825)

==9761==    by 0x8977D1: mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool) (sql_parse.cc:8141)

==9761==    by 0x882DBF: dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool) (sql_parse.cc:1820)

==9761==    by 0x88162F: do_command(THD*) (sql_parse.cc:1358)

==9761==    by 0x9FCA3E: do_handle_one_connection(CONNECT*) (sql_connect.cc:1399)

==9761==    by 0x9FC7AF: handle_one_connection (sql_connect.cc:1302)

==9761==    by 0xF13C2C: pfs_spawn_thread (pfs.cc:1862)

==9761==    by 0x4E3F493: start_thread (pthread_create.c:333)