Commit 211164ff authored by Gleb Shchepa's avatar Gleb Shchepa
Browse files

Bug #37761: IN handles NULL differently for table-subquery 

            and value-list

The server returns unexpected results if a right side of the 
NOT IN clause consists of NULL value and some constants of
the same type, for example:

  SELECT * FROM t WHERE NOT t.id IN (NULL, 1, 2) 
  
may return 3, 4, 5 etc if a table contains these values.


The Item_func_in::val_int method has been modified:
unnecessary resets of an Item_func_case::has_null field 
value has been moved outside of an argument comparison
loop. (Also unnecessary re-initialization of the null_value
field has been moved).
parent 6d05a62e

mysql-test/r/func_in.result

+6 −0
Original line number Diff line number Diff line
@@ -569,4 +569,10 @@ insert into t1 values (),(),(),(),(),(),(),(),(),(); 
select a from t1 where a not in (a,a,a) group by a;

a

drop table t1;

create table t1 (id int);

select * from t1 where NOT id in (select null union all select 1);

id

select * from t1 where NOT id in (null, 1);

id

drop table t1;

End of 5.1 tests

mysql-test/t/func_in.test

+9 −0
Original line number Diff line number Diff line
@@ -417,4 +417,13 @@ insert into t1 values (),(),(),(),(),(),(),(),(),(); 
select a from t1 where a not in (a,a,a) group by a;

drop table t1;



#

# Bug #37761: IN handles NULL differently for table-subquery and value-list

#



create table t1 (id int);

select * from t1 where NOT id in (select null union all select 1);

select * from t1 where NOT id in (null, 1);

drop table t1;



--echo End of 5.1 tests

sql/item_cmpfunc.cc

+3 −3
Original line number Diff line number Diff line
@@ -3758,6 +3758,9 @@ longlong Item_func_in::val_int() 
    return (longlong) (!null_value && tmp != negated);

  }



  if ((null_value= args[0]->null_value))

    return 0;

  have_null= 0;

  for (uint i= 1 ; i < arg_count ; i++)

  {

    Item_result cmp_type= item_cmp_type(left_result_type, args[i]->result_type());
@@ -3766,9 +3769,6 @@ longlong Item_func_in::val_int() 
    if (!(value_added_map & (1 << (uint)cmp_type)))

    {

      in_item->store_value(args[0]);

      if ((null_value=args[0]->null_value))

        return 0;

      have_null= 0;

      value_added_map|= 1 << (uint)cmp_type;

    }

    if (!in_item->cmp(args[i]) && !args[i]->null_value)