Hi Jørgen,
Thanks for the patch. Code changes looks good. I have some minor
suggestions. I also suggest to include in the test case some scenarios
where arguments are actually NULL. See in-line for comments.
On 01/31/2011 02:39 PM, Jorgen Loland wrote:
> #At file:///export/home/jl208045/mysql/mysql-trunk-59405/ based on
> revid:sandeep.doddaballapur@stripped
>
> 3578 Jorgen Loland 2011-01-31
> BUG#59405: FIND_IN_SET won't work normaly after upgrade
> from 5.1 to 5.5
>
> In this bug, args[0] in an Item_func_find_in_set stored an
> Item_func_weekday that was constant. In
> Item_func_find_in_set::fix_length_and_dec(), args[0]->val_str()
> was called. Later, when Item_func_find_in_set::val_int() was
> called, args[0]->null_value was checked. However, the
> Item_func_weekday in args[0] had now been replaced with an
> Item_cache. No val_*() calls had been made to this Item_cache,
> thus null_value was incorrectly 'true', resulting in missing
> rows in the result set.
>
> The implemented fix is to remember args[0]->null_value as it
> was right after calling it's val_str() in fix_length_and_dec().
> Note: this only applies if args[0] is constant.
>
> An alternative fix would be to call args[0]->val_int() inside
> Item_func_find_in_set::val_int(), but that would have to be
> done for every record this const value is checked against.
> @ mysql-test/r/func_set.result
> Add test for BUG#59405
> @ mysql-test/t/func_set.test
> Add test for BUG#59405
> @ sql/item_func.cc
> Add variable Item_func_find_in_set::args_0_null_value
> @ sql/item_func.h
> Add variable Item_func_find_in_set::args_0_null_value
>
> modified:
> mysql-test/r/func_set.result
> mysql-test/t/func_set.test
> sql/item_func.cc
> sql/item_func.h
> === modified file 'mysql-test/r/func_set.result'
> --- a/mysql-test/r/func_set.result 2009-06-16 14:36:15 +0000
> +++ b/mysql-test/r/func_set.result 2011-01-31 13:39:14 +0000
> @@ -159,3 +159,15 @@ SELECT CONVERT( a USING latin1 ) FROM t2
> CONVERT( a USING latin1 )
>
> DROP TABLE t1, t2;
> +#
> +# BUG#59405: FIND_IN_SET won't work normaly after upgrade from 5.1 to 5.5
> +#
> +CREATE TABLE t1(days set('1','2','3','4','5','6','7'));
> +INSERT INTO t1 VALUES('1,2,3,4,5,6,7'), ('1,2,3,4,5,6,7');
> +
> +SELECT * FROM t1 WHERE FIND_IN_SET(DAYOFWEEK(CURRENT_DATE()),days);
> +days
> +1,2,3,4,5,6,7
> +1,2,3,4,5,6,7
> +
> +DROP TABLE t1;
>
> === modified file 'mysql-test/t/func_set.test'
> --- a/mysql-test/t/func_set.test 2009-06-16 14:36:15 +0000
> +++ b/mysql-test/t/func_set.test 2011-01-31 13:39:14 +0000
> @@ -97,3 +97,16 @@ SELECT CONVERT( a USING latin1 ) FROM t1
> SELECT CONVERT( a USING latin1 ) FROM t2;
>
> DROP TABLE t1, t2;
> +
> +--echo #
> +--echo # BUG#59405: FIND_IN_SET won't work normaly after upgrade from 5.1 to 5.5
> +--echo #
> +
> +CREATE TABLE t1(days set('1','2','3','4','5','6','7'));
> +INSERT INTO t1 VALUES('1,2,3,4,5,6,7'), ('1,2,3,4,5,6,7');
I suggest also including a row where value is NULL. E.g.,
INSERT INTO t1 VALUES('1,2,3,4,5,6,7'), NULL, ('1,2,3,4,5,6,7');
> +
> +--echo
> +SELECT * FROM t1 WHERE FIND_IN_SET(DAYOFWEEK(CURRENT_DATE()),days);
To test some aspects of NULL values in arguments, I suggest adding a few
queries like the following:
SELECT * FROM t1 WHERE FIND_IN_SET(DAYOFWEEK(CURRENT_DATE()),days) IS
UNKNOWN;
SELECT * FROM t1 WHERE FIND_IN_SET(DAYOFWEEK(CURRENT_DATE()),NULL) IS
UNKNOWN;
SELECT * FROM t1 WHERE FIND_IN_SET(NULL,days) IS UNKNOWN;
SELECT * FROM t1 WHERE FIND_IN_SET(NULL,NULL) IS UNKNOWN;
It could not find any existing tests for FIND_IN_SET with NULL arguments.
> +
> +--echo
> +DROP TABLE t1;
>
> === modified file 'sql/item_func.cc'
> --- a/sql/item_func.cc 2011-01-14 15:36:19 +0000
> +++ b/sql/item_func.cc 2011-01-31 13:39:14 +0000
> @@ -3019,6 +3019,12 @@ void Item_func_find_in_set::fix_length_a
> if (field->real_type() == MYSQL_TYPE_SET)
> {
> String *find=args[0]->val_str(&value);
> + /*
> + Because it is constant, args[0] may be replaced by an Item_cache.
> + Store null_value here to avoid args[0]->val_int() before checking
> + the null_value in Item_func_find_in_set::val_int().
> + */
> + args_0_null_value= args[0]->null_value;
> if (find)
> {
> enum_value= find_type(((Field_enum*) field)->typelib,find->ptr(),
> @@ -3039,8 +3045,12 @@ longlong Item_func_find_in_set::val_int(
> DBUG_ASSERT(fixed == 1);
> if (enum_value)
> {
> + // enum_value is set iff args[0]->const_item() in fix_length_and_dec().
> + DBUG_ASSERT(args[0]->const_item());
> +
> ulonglong tmp=(ulonglong) args[1]->val_int();
> - if (!(null_value=args[1]->null_value || args[0]->null_value))
> + null_value= args[1]->null_value;
The above assignments are not equivalent. Previously, null_value was
true if either of the arguments where null. Now, it seems it is only
affected by argument 1. However, I have not been able to produce a test
case where this seems to matter. But to be sure, I suggest adding the
follow before calling args[1]->val_int():
if (null_value= args_0_null_value) return 0;
(There is no need to evaluate argument 1 if argument 0 is NULL.)
> + if (!null_value&& !args_0_null_value)
> {
> if (tmp& enum_bit)
> return enum_value;
>
> === modified file 'sql/item_func.h'
> --- a/sql/item_func.h 2011-01-28 13:49:59 +0000
> +++ b/sql/item_func.h 2011-01-31 13:39:14 +0000
> @@ -1025,9 +1025,11 @@ class Item_func_find_in_set :public Item
> String value,value2;
> uint enum_value;
> ulonglong enum_bit;
> + bool args_0_null_value; /* Cache args[0]->null_value iff args[0] is const */
It seems to me that "arg0_" is a more common prefix in the code than
"args_0_", but I will not insist on anything.
> DTCollation cmp_collation;
> public:
> - Item_func_find_in_set(Item *a,Item *b) :Item_int_func(a,b),enum_value(0) {}
> + Item_func_find_in_set(Item *a,Item *b)
> + : Item_int_func(a,b), enum_value(0), args_0_null_value(false) {}
> longlong val_int();
> const char *func_name() const { return "find_in_set"; }
> void fix_length_and_dec();
>
>
>
>
>
--
Øystein
