Commit fbb23326 authored by evgen@moonbone.local's avatar evgen@moonbone.local
Browse files

Bug#28208: Wrong result of a non-const STRING function with a const DATETIME 

function.

A wrong  condition was used to check that the
Arg_comparator::can_compare_as_dates() function calculated the value of the
string constant. When comparing a non-const STRING function with a constant
DATETIME function it leads to saving an arbitrary value as a cached value of
the DATETIME function.

Now the Arg_comparator::set_cmp_func() function initializes the const_value
variable to the impossible DATETIME value (-1) and this const_value is
cached only if it was changed by the Arg_comparator::can_compare_as_dates()
function.
parent 22dfb9f0

mysql-test/r/type_datetime.result

+6 −0
Original line number Diff line number Diff line
@@ -346,3 +346,9 @@ call test27759(); 
a	b	a_then_b	b_then_a	c_then_a

2007-04-10	2007-04-11	2007-04-10	2007-04-10	2004-04-09 00:00:00

drop procedure test27759;

create table t1 (f1 date);

insert into t1 values (curdate());

select left(f1,10) = curdate() from t1;

left(f1,10) = curdate()

1

drop table t1;

mysql-test/t/type_datetime.test

+9 −0
Original line number Diff line number Diff line
@@ -225,3 +225,12 @@ END;| 
DELIMITER ;|

call test27759();

drop procedure test27759;



#

# Bug#28208: Wrong result of a non-const STRING function with a const

#            DATETIME function.

#

create table t1 (f1 date);

insert into t1 values (curdate());

select left(f1,10) = curdate() from t1;

drop table t1;

sql/item_cmpfunc.cc

+2 −3
Original line number Diff line number Diff line
@@ -661,7 +661,7 @@ int Arg_comparator::set_cmp_func(Item_bool_func2 *owner_arg, 
                                        Item_result type)

{

  enum enum_date_cmp_type cmp_type;

  ulonglong const_value;

  ulonglong const_value= (ulonglong)-1;

  a= a1;

  b= a2;
@@ -674,8 +674,7 @@ int Arg_comparator::set_cmp_func(Item_bool_func2 *owner_arg, 
    a_cache= 0;

    b_cache= 0;



    if (cmp_type != CMP_DATE_WITH_DATE &&

        ((*b)->const_item() || (*a)->const_item()))

    if (const_value != (ulonglong)-1)

    {

      Item_cache_int *cache= new Item_cache_int();

      /* Mark the cache as non-const to prevent re-caching. */