From e40e8052e89ada24a79c827cf38271beed756759 Mon Sep 17 00:00:00 2001 From: unknown Date: Thu, 16 Nov 2006 13:21:38 +0300 Subject: [PATCH 1/2] BUG#17047: CHAR() and IN() can return NULL without signaling NULL result The problem was that some functions (namely IN() starting with 4.1, and CHAR() starting with 5.0) were returning NULL in certain conditions, while they didn't set their maybe_null flag. Because of that there could be some problems with 'IS NULL' check, and statements that depend on the function value domain, like CREATE TABLE t1 SELECT 1 IN (2, NULL);. The fix is to set maybe_null correctly. mysql-test/r/func_in.result: Add result for bug#17047: CHAR() and IN() can return NULL without signaling NULL result. mysql-test/t/func_in.test: Add test case for bug#17047: CHAR() and IN() can return NULL without signaling NULL result. sql/item_cmpfunc.cc: Remove assignment to maybe_null, as it was already set in fix_fields() based on all arguments, not only on the first. --- mysql-test/r/func_in.result | 8 ++++++++ mysql-test/t/func_in.test | 22 +++++++++++++++++++++- sql/item_cmpfunc.cc | 1 - 3 files changed, 29 insertions(+), 2 deletions(-) diff --git a/mysql-test/r/func_in.result b/mysql-test/r/func_in.result index 3cf2afc83d1..f74c63f7260 100644 --- a/mysql-test/r/func_in.result +++ b/mysql-test/r/func_in.result @@ -202,3 +202,11 @@ select count(*) from t1 where id not in (1,2); count(*) 1 drop table t1; +DROP TABLE IF EXISTS t1; +CREATE TABLE t1 SELECT 1 IN (2, NULL); +SELECT should return NULL. +SELECT * FROM t1; +1 IN (2, NULL) +NULL +DROP TABLE t1; +End of 4.1 tests diff --git a/mysql-test/t/func_in.test b/mysql-test/t/func_in.test index 2ffe5a2d5f7..ffed2aac2a0 100644 --- a/mysql-test/t/func_in.test +++ b/mysql-test/t/func_in.test @@ -109,4 +109,24 @@ select count(*) from t1 where id not in (1); select count(*) from t1 where id not in (1,2); drop table t1; -# End of 4.1 tests + +# +# BUG#17047: CHAR() and IN() can return NULL without signaling NULL +# result +# +# The problem was in the IN() function that ignored maybe_null flags +# of all arguments except the first (the one _before_ the IN +# keyword, '1' in the test case below). +# +--disable_warnings +DROP TABLE IF EXISTS t1; +--enable_warnings + +CREATE TABLE t1 SELECT 1 IN (2, NULL); +--echo SELECT should return NULL. +SELECT * FROM t1; + +DROP TABLE t1; + + +--echo End of 4.1 tests diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc index 6b6996160a1..859b4e0ecc1 100644 --- a/sql/item_cmpfunc.cc +++ b/sql/item_cmpfunc.cc @@ -1998,7 +1998,6 @@ void Item_func_in::fix_length_and_dec() if (cmp_type == STRING_RESULT) in_item->cmp_charset= cmp_collation.collation; } - maybe_null= args[0]->maybe_null; max_length= 1; } From af22eb35e577ef17226faf662f2cffc4705bde26 Mon Sep 17 00:00:00 2001 From: unknown Date: Thu, 16 Nov 2006 14:06:51 +0300 Subject: [PATCH 2/2] Add 5.0 part of fix for bug 17047. mysql-test/r/func_str.result: Add result for bug#17047: CHAR() and IN() can return NULL without signaling NULL result. mysql-test/t/func_str.test: Add test case for bug#17047: CHAR() and IN() can return NULL without signaling NULL result. sql/item_strfunc.cc: Add Item_str_func::fix_fields() implementation, and set maybe_null to TRUE if we are in the SQL mode that requires some functions to return null even if they normally do not. sql/item_strfunc.h: Add declaration of Item_str_func::fix_fields(). Do not reset maybe_null in Item_func_char::fix_length_and_dec(). --- mysql-test/r/func_str.result | 13 +++++++++++++ mysql-test/t/func_str.test | 14 ++++++++++++++ sql/item_strfunc.cc | 14 ++++++++++++++ sql/item_strfunc.h | 6 +++--- 4 files changed, 44 insertions(+), 3 deletions(-) diff --git a/mysql-test/r/func_str.result b/mysql-test/r/func_str.result index c2c12f8d291..9588827d234 100644 --- a/mysql-test/r/func_str.result +++ b/mysql-test/r/func_str.result @@ -1148,4 +1148,17 @@ id select_type table type possible_keys key key_len ref rows Extra Warnings: Note 1003 select `test`.`t1`.`code` AS `code`,`test`.`t2`.`id` AS `id` from `test`.`t1` join `test`.`t2` where ((`test`.`t1`.`code` = _latin1'a12') and (length(`test`.`t1`.`code`) = 5)) DROP TABLE t1,t2; +SET @orig_sql_mode = @@SQL_MODE; +SET SQL_MODE=traditional; +SELECT CHAR(0xff,0x8f USING utf8); +CHAR(0xff,0x8f USING utf8) +NULL +Warnings: +Error 1300 Invalid utf8 character string: 'FF8F' +SELECT CHAR(0xff,0x8f USING utf8) IS NULL; +CHAR(0xff,0x8f USING utf8) IS NULL +1 +Warnings: +Error 1300 Invalid utf8 character string: 'FF8F' +SET SQL_MODE=@orig_sql_mode; End of 5.0 tests diff --git a/mysql-test/t/func_str.test b/mysql-test/t/func_str.test index 45415882ac7..9255669f6e3 100644 --- a/mysql-test/t/func_str.test +++ b/mysql-test/t/func_str.test @@ -780,4 +780,18 @@ SELECT * FROM t1 INNER JOIN t2 ON code=id DROP TABLE t1,t2; + +# +# BUG#17047: CHAR() and IN() can return NULL without signaling NULL +# result +# +SET @orig_sql_mode = @@SQL_MODE; +SET SQL_MODE=traditional; + +SELECT CHAR(0xff,0x8f USING utf8); +SELECT CHAR(0xff,0x8f USING utf8) IS NULL; + +SET SQL_MODE=@orig_sql_mode; + + --echo End of 5.0 tests diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc index 31c2f44fc3e..b54f8fef90c 100644 --- a/sql/item_strfunc.cc +++ b/sql/item_strfunc.cc @@ -80,6 +80,20 @@ String *Item_str_func::check_well_formed_result(String *str) } +bool Item_str_func::fix_fields(THD *thd, Item **ref) +{ + bool res= Item_func::fix_fields(thd, ref); + /* + In Item_str_func::check_well_formed_result() we may set null_value + flag on the same condition as in test() below. + */ + maybe_null= (maybe_null || + test(thd->variables.sql_mode & + (MODE_STRICT_TRANS_TABLES | MODE_STRICT_ALL_TABLES))); + return res; +} + + my_decimal *Item_str_func::val_decimal(my_decimal *decimal_value) { DBUG_ASSERT(fixed == 1); diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h index 528180b803d..fd2aaf19675 100644 --- a/sql/item_strfunc.h +++ b/sql/item_strfunc.h @@ -37,6 +37,7 @@ public: enum Item_result result_type () const { return STRING_RESULT; } void left_right_max_length(); String *check_well_formed_result(String *str); + bool fix_fields(THD *thd, Item **ref); }; class Item_func_md5 :public Item_str_func @@ -525,9 +526,8 @@ public: { collation.set(cs); } String *val_str(String *); void fix_length_and_dec() - { - maybe_null=0; - max_length=arg_count * collation.collation->mbmaxlen; + { + max_length= arg_count * collation.collation->mbmaxlen; } const char *func_name() const { return "char"; } };