Valgrind warnings (Conditional jump or move depends on uninitialised value) in my_strtoll10

CREATE TABLE t1 (d DATE NOT NULL) ENGINE=MyISAM;

INSERT INTO t1 VALUES ('2008-03-24'),('2004-04-21');

SELECT * FROM t1 WHERE COALESCE( d, '2009-12-11' ) IS NULL;

==5889== Thread 4:

==5889== Conditional jump or move depends on uninitialised value(s)

==5889==    at 0xC29B25: my_strtoll10 (my_strtoll10.c:112)

==5889==    by 0xC04995: my_strtoll10_8bit (ctype-simple.c:1386)

==5889==    by 0x5B20C8: Item_func_numhybrid::val_int() (item_func.cc:916)

==5889==    by 0x59888E: Item::update_null_value() (item.h:955)

==5889==    by 0x5C523A: Item_func_numhybrid::is_null() (item_func.h:398)

==5889==    by 0x5D81C6: Item_func_isnull::val_int() (item_cmpfunc.cc:4624)

==5889==    by 0x5AF3E9: eval_const_cond(Item*) (item_func.cc:63)

==5889==    by 0x72DFF6: remove_eq_conds(THD*, Item*, Item::cond_result*) (sql_select.cc:13568)

==5889==    by 0x72D080: optimize_cond(JOIN*, Item*, List<TABLE_LIST>*, bool, Item::cond_result*, COND_EQUAL**) (sql_select.cc:13145)

==5889==    by 0x70D6F9: JOIN::optimize() (sql_select.cc:1019)

==5889==    by 0x714BAA: mysql_select(THD*, Item***, 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:2993)

==5889==    by 0x70B4CE: handle_select(THD*, st_lex*, select_result*, unsigned long) (sql_select.cc:288)

==5889==    by 0x696932: execute_sqlcom_select(THD*, TABLE_LIST*) (sql_parse.cc:5172)

==5889==    by 0x68D6F1: mysql_execute_command(THD*) (sql_parse.cc:2305)

==5889==    by 0x6993AC: mysql_parse(THD*, char*, unsigned int, char const**) (sql_parse.cc:6173)

==5889==    by 0x68AE95: dispatch_command(enum_server_command, THD*, char*, unsigned int) (sql_parse.cc:1243)

revision-id: igor@askmonty.org-20130817050147-k5dvrilf0u0vz8cr

revno: 3677

branch-nick: 5.3