Commit 707e676c authored by Ramil Kalimullin's avatar Ramil Kalimullin
Browse files

Fix for bug#37526: asymertic operator <=> in trigger 

Problem: <=> operator may return wrong results 
comparing NULL and a DATE/DATETIME/TIME value.

Fix: properly check NULLs.
parent 0994c961

mysql-test/r/type_datetime.result

+23 −0
Original line number Diff line number Diff line
@@ -560,4 +560,27 @@ select * from t2 
where id in (select id from t2 as x1 where (t2.cur_date is null));

id	cur_date

drop table t1,t2;

SELECT 

CAST('NULL' AS DATE) <=> CAST('2008-01-01' AS DATE) n1, 

CAST('2008-01-01' AS DATE) <=> CAST('NULL' AS DATE) n2,

CAST('NULL' AS DATE) <=> CAST('NULL' AS DATE) n3,

CAST('NULL' AS DATE) <> CAST('2008-01-01' AS DATE) n4, 

CAST('2008-01-01' AS DATE) <> CAST('NULL' AS DATE) n5,

CAST('NULL' AS DATE) <> CAST('NULL' AS DATE) n6,

CAST('NULL' AS DATE) < CAST('2008-01-01' AS DATE) n7, 

CAST('2008-01-01' AS DATE) < CAST('NULL' AS DATE) n8,

CAST('NULL' AS DATE) < CAST('NULL' AS DATE) n9;

n1	n2	n3	n4	n5	n6	n7	n8	n9

0	0	1	NULL	NULL	NULL	NULL	NULL	NULL

Warnings:

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

Warning	1292	Truncated incorrect datetime value: 'NULL'

End of 5.0 tests

mysql-test/t/type_datetime.test

+16 −0
Original line number Diff line number Diff line
@@ -388,4 +388,20 @@ where id in (select id from t2 as x1 where (t2.cur_date is null)); 


drop table t1,t2;





#

# Bug #37526: asymertic operator <=> in trigger

#

SELECT 

  CAST('NULL' AS DATE) <=> CAST('2008-01-01' AS DATE) n1, 

  CAST('2008-01-01' AS DATE) <=> CAST('NULL' AS DATE) n2,

  CAST('NULL' AS DATE) <=> CAST('NULL' AS DATE) n3,

  CAST('NULL' AS DATE) <> CAST('2008-01-01' AS DATE) n4, 

  CAST('2008-01-01' AS DATE) <> CAST('NULL' AS DATE) n5,

  CAST('NULL' AS DATE) <> CAST('NULL' AS DATE) n6,

  CAST('NULL' AS DATE) < CAST('2008-01-01' AS DATE) n7, 

  CAST('2008-01-01' AS DATE) < CAST('NULL' AS DATE) n8,

  CAST('NULL' AS DATE) < CAST('NULL' AS DATE) n9;





--echo End of 5.0 tests

sql/item_cmpfunc.cc

+13 −7
Original line number Diff line number Diff line
@@ -966,19 +966,24 @@ get_datetime_value(THD *thd, Item ***item_arg, Item **cache_arg, 
       1    if items are equal or both are null

       0    otherwise

    If is_nulls_eq is FALSE:

      -1   a < b or one of items is null

      -1   a < b or at least one item is null

       0   a == b

       1   a > b

    See the table:

    is_nulls_eq | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |

    a_is_null   | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 |

    b_is_null   | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 0 |

    result      | 1 | 0 | 0 |0/1|-1 |-1 |-1 |-1/0/1|

*/



int Arg_comparator::compare_datetime()

{

  bool is_null= FALSE;

  bool a_is_null, b_is_null;

  ulonglong a_value, b_value;



  /* Get DATE/DATETIME/TIME value of the 'a' item. */

  a_value= (*get_value_func)(thd, &a, &a_cache, *b, &is_null);

  if (!is_nulls_eq && is_null)

  a_value= (*get_value_func)(thd, &a, &a_cache, *b, &a_is_null);

  if (!is_nulls_eq && a_is_null)

  {

    if (owner)

      owner->null_value= 1;
@@ -986,14 +991,15 @@ int Arg_comparator::compare_datetime() 
  }



  /* Get DATE/DATETIME/TIME value of the 'b' item. */

  b_value= (*get_value_func)(thd, &b, &b_cache, *a, &is_null);

  if (is_null)

  b_value= (*get_value_func)(thd, &b, &b_cache, *a, &b_is_null);

  if (a_is_null || b_is_null)

  {

    if (owner)

      owner->null_value= is_nulls_eq ? 0 : 1;

    return is_nulls_eq ? 1 : -1;

    return is_nulls_eq ? (a_is_null == b_is_null) : -1;

  }



  /* Here we have two not-NULL values. */

  if (owner)

    owner->null_value= 0;