mi_rrnd: Conditional jump or move depends on uninitialised value upon inserting into blob with long key

CREATE TABLE t1 (b BLOB, UNIQUE(b)) ENGINE=MyISAM;

REPLACE INTO t1 VALUES (0),(3);

--error 0,1062

REPLACE INTO t1 VALUES (0),(3);

# Cleanup

DROP TABLE t1;

==16800== Conditional jump or move depends on uninitialised value(s)

==16800==    at 0x1372E5B: mi_rrnd (mi_rrnd.c:40)

==16800==    by 0x13361B9: ha_myisam::rnd_pos(unsigned char*, unsigned char*) (ha_myisam.cc:2010)

==16800==    by 0xBE9F51: handler::ha_rnd_pos(unsigned char*, unsigned char*) (handler.cc:3014)

==16800==    by 0x84AB5E: write_record(THD*, TABLE*, st_copy_info*) (sql_insert.cc:1754)

==16800==    by 0x848DD0: mysql_insert(THD*, TABLE_LIST*, List<Item>&, List<List<Item> >&, List<Item>&, List<Item>&, enum_duplicates, bool) (sql_insert.cc:1067)

==16800==    by 0x894749: mysql_execute_command(THD*) (sql_parse.cc:4791)

==16800==    by 0x8A05C7: mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool) (sql_parse.cc:8157)

==16800==    by 0x88BB69: dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool) (sql_parse.cc:1829)

==16800==    by 0x88A33D: do_command(THD*) (sql_parse.cc:1358)

==16800==    by 0xA09F42: do_handle_one_connection(CONNECT*) (sql_connect.cc:1399)

==16800==    by 0xA09CB3: handle_one_connection (sql_connect.cc:1302)

==16800==    by 0xF24948: pfs_spawn_thread (pfs.cc:1862)

==16800==    by 0x4E3F493: start_thread (pthread_create.c:333)

==16800==    by 0x6A9A93E: clone (clone.S:97)

==16800== Conditional jump or move depends on uninitialised value(s)

==16800==    at 0x1358562: _mi_read_rnd_dynamic_record (mi_dynrec.c:1746)

==16800==    by 0x1372F45: mi_rrnd (mi_rrnd.c:59)

==16800==    by 0x13361B9: ha_myisam::rnd_pos(unsigned char*, unsigned char*) (ha_myisam.cc:2010)

==16800==    by 0xBE9F51: handler::ha_rnd_pos(unsigned char*, unsigned char*) (handler.cc:3014)

==16800==    by 0x84AB5E: write_record(THD*, TABLE*, st_copy_info*) (sql_insert.cc:1754)

==16800==    by 0x848DD0: mysql_insert(THD*, TABLE_LIST*, List<Item>&, List<List<Item> >&, List<Item>&, List<Item>&, enum_duplicates, bool) (sql_insert.cc:1067)

==16800==    by 0x894749: mysql_execute_command(THD*) (sql_parse.cc:4791)

==16800==    by 0x8A05C7: mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool) (sql_parse.cc:8157)

==16800==    by 0x88BB69: dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool) (sql_parse.cc:1829)

==16800==    by 0x88A33D: do_command(THD*) (sql_parse.cc:1358)

==16800==    by 0xA09F42: do_handle_one_connection(CONNECT*) (sql_connect.cc:1399)

==16800==    by 0xA09CB3: handle_one_connection (sql_connect.cc:1302)

==16800==    by 0xF24948: pfs_spawn_thread (pfs.cc:1862)

==16800==    by 0x4E3F493: start_thread (pthread_create.c:333)

==16800==    by 0x6A9A93E: clone (clone.S:97)

==16800== Conditional jump or move depends on uninitialised value(s)

==16800==    at 0x13585C6: _mi_read_rnd_dynamic_record (mi_dynrec.c:1755)

==16800==    by 0x1372F45: mi_rrnd (mi_rrnd.c:59)

==16800==    by 0x13361B9: ha_myisam::rnd_pos(unsigned char*, unsigned char*) (ha_myisam.cc:2010)

==16800==    by 0xBE9F51: handler::ha_rnd_pos(unsigned char*, unsigned char*) (handler.cc:3014)

==16800==    by 0x84AB5E: write_record(THD*, TABLE*, st_copy_info*) (sql_insert.cc:1754)

==16800==    by 0x848DD0: mysql_insert(THD*, TABLE_LIST*, List<Item>&, List<List<Item> >&, List<Item>&, List<Item>&, enum_duplicates, bool) (sql_insert.cc:1067)

==16800==    by 0x894749: mysql_execute_command(THD*) (sql_parse.cc:4791)

==16800==    by 0x8A05C7: mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool) (sql_parse.cc:8157)

==16800==    by 0x88BB69: dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool) (sql_parse.cc:1829)

==16800==    by 0x88A33D: do_command(THD*) (sql_parse.cc:1358)

==16800==    by 0xA09F42: do_handle_one_connection(CONNECT*) (sql_connect.cc:1399)

==16800==    by 0xA09CB3: handle_one_connection (sql_connect.cc:1302)

==16800==    by 0xF24948: pfs_spawn_thread (pfs.cc:1862)

==16800==    by 0x4E3F493: start_thread (pthread_create.c:333)

==16800==    by 0x6A9A93E: clone (clone.S:97)