Commit 7f9411c1 authored by evgen@moonbone.local's avatar evgen@moonbone.local
Browse files

Bug#23656: Wrong conversion result of a DATETIME to integer using CAST function. 

The generic string to int conversion was used by the Item_func_signed and
the Item_func_unsigned classes to convert DATE/DATETIME values to the
SIGNED/UNSIGNED type. But this conversion produces wrong results for such
values.

Now if the item which result has to be converted can return its result as
longlong then the item->val_int() method is used to allow the item to carry
out the conversion itself and return the correct result.
This condition is checked in the Item_func_signed::val_int() and the
Item_func_unsigned::val_int() functions.
parent 395d8751

mysql-test/r/cast.result

+6 −0
Original line number Diff line number Diff line
@@ -281,4 +281,10 @@ DROP TABLE t1; 
select isnull(date(NULL)), isnull(cast(NULL as DATE));

isnull(date(NULL))	isnull(cast(NULL as DATE))

1	1

SELECT CAST(cast('01-01-01' as date) AS UNSIGNED);

CAST(cast('01-01-01' as date) AS UNSIGNED)

20010101

SELECT CAST(cast('01-01-01' as date) AS SIGNED);

CAST(cast('01-01-01' as date) AS SIGNED)

20010101

End of 4.1 tests

mysql-test/t/cast.test

+6 −0
Original line number Diff line number Diff line
@@ -173,4 +173,10 @@ DROP TABLE t1; 


select isnull(date(NULL)), isnull(cast(NULL as DATE));



#

# Bug#23656: Wrong result of CAST from DATE to int

#

SELECT CAST(cast('01-01-01' as date) AS UNSIGNED);

SELECT CAST(cast('01-01-01' as date) AS SIGNED);



--echo End of 4.1 tests

sql/item_func.cc

+4 −2
Original line number Diff line number Diff line
@@ -477,7 +477,8 @@ longlong Item_func_signed::val_int() 
  longlong value;

  int error;



  if (args[0]->cast_to_int_type() != STRING_RESULT)

  if (args[0]->cast_to_int_type() != STRING_RESULT ||

      args[0]->result_as_longlong())

  {

    value= args[0]->val_int();

    null_value= args[0]->null_value;
@@ -529,7 +530,8 @@ longlong Item_func_unsigned::val_int() 
    return (longlong)  (dvalue + (dvalue > 0 ? 0.5 : -0.5));

  }



  if (args[0]->cast_to_int_type() != STRING_RESULT)

  if (args[0]->cast_to_int_type() != STRING_RESULT ||

      args[0]->result_as_longlong())

  {

    value= args[0]->val_int();

    null_value= args[0]->null_value;