Commit ba18c0bf authored by gshchepa/uchum@host.loc's avatar gshchepa/uchum@host.loc
Browse files

Fixed bug #36488: regexp returns false matches, concatenating 

                  with previous rows.

The WHERE clause containing expression:
  CONCAT(empty_field1, empty_field2, ..., 'literal constant', ...)
    REGEXP 'regular expression'
may return wrong matches.

Optimization of the CONCAT function has been fixed.
parent 5eaa7794

mysql-test/r/func_concat.result

+7 −0
Original line number Diff line number Diff line
@@ -82,3 +82,10 @@ a 
1234562

x

drop table t1;

CREATE TABLE t1 (c1 varchar(100), c2 varchar(100));

INSERT INTO t1 VALUES ('',''), ('','First'), ('Random','Random');

SELECT * FROM t1 WHERE CONCAT(c1,' ',c2) REGEXP 'First.*';

c1	c2

	First

DROP TABLE t1;

# End of 5.0 tests

mysql-test/t/func_concat.test

+10 −0
Original line number Diff line number Diff line
@@ -68,3 +68,13 @@ create table t1(f1 varchar(6)) charset=utf8; 
insert into t1 values ("123456");

select concat(f1, 2) a from t1 union select 'x' a from t1;

drop table t1;



#

# Bug #36488: regexp returns false matches, concatenating with previous rows

#

CREATE TABLE t1 (c1 varchar(100), c2 varchar(100));

INSERT INTO t1 VALUES ('',''), ('','First'), ('Random','Random');

SELECT * FROM t1 WHERE CONCAT(c1,' ',c2) REGEXP 'First.*';

DROP TABLE t1;



--echo # End of 5.0 tests

sql/item_strfunc.cc

+6 −0
Original line number Diff line number Diff line
@@ -294,6 +294,12 @@ String *Item_func_concat::val_str(String *str) 
    {

      if (!(res=args[i]->val_str(str)))

	goto null;

      /*

       CONCAT accumulates its result in the result of its the first

       non-empty argument. Because of this we need is_const to be 

       evaluated only for it.

      */

      is_const= args[i]->const_item() || !args[i]->used_tables();

    }

    else

    {