Fix bug#11325 Wrong date comparison in views

Wrong comparing method were choosen which results in false comparison.

Make Item_bool_func2::fix_length_and_dec() to get type and field from
real_item() to make REF_ITEM pass the check. 


sql/item_cmpfunc.cc:
  Fix bug#11325 Wrong date comparison in views
mysql-test/t/view.test:
  Test case for bug#11325 Wrong date comparison in views.
mysql-test/r/view.result:
  Test case for bug#11325 Wrong date comparison in views.

mysql-test/r/view.result

@@ -1831,3 +1831,14 @@ select * from v1;
 t
 01:00
 drop view v1;
+create table t1 (f1 date);
+insert into t1 values ('2005-01-01'),('2005-02-02');
+create view v1 as select * from t1;
+select * from v1 where f1='2005.02.02';
+f1
+2005-02-02
+select * from v1 where '2005.02.02'=f1;
+f1
+2005-02-02
+drop view v1;
+drop table t1;

mysql-test/t/view.test

@@ -1673,3 +1673,14 @@ create view v1(k, K) as select 1,2;
 create view v1 as SELECT TIME_FORMAT(SEC_TO_TIME(3600),'%H:%i') as t;
 select * from v1;
 drop view v1;
+
+#
+# bug #11325 Wrong date comparison in views
+#
+create table t1 (f1 date);
+insert into t1 values ('2005-01-01'),('2005-02-02');
+create view v1 as select * from t1;
+select * from v1 where f1='2005.02.02';
+select * from v1 where '2005.02.02'=f1;
+drop view v1;
+drop table t1;

sql/item_cmpfunc.cc

@@ -238,9 +238,10 @@ void Item_bool_func2::fix_length_and_dec()
     return;
   }
     
-  if (args[0]->type() == FIELD_ITEM)
+  Item *real_item= args[0]->real_item();
+  if (real_item->type() == FIELD_ITEM)
   {
-    Field *field=((Item_field*) args[0])->field;
+    Field *field= ((Item_field*) real_item)->field;
     if (field->can_be_compared_as_longlong())
     {
       if (convert_constant_item(thd, field,&args[1]))
@@ -251,9 +252,10 @@ void Item_bool_func2::fix_length_and_dec()
       }
     }
   }
-  if (args[1]->type() == FIELD_ITEM /* && !args[1]->const_item() */)
+  real_item= args[1]->real_item();
+  if (real_item->type() == FIELD_ITEM)
   {
-    Field *field=((Item_field*) args[1])->field;
+    Field *field= ((Item_field*) real_item)->field;
     if (field->can_be_compared_as_longlong())
     {
       if (convert_constant_item(thd, field,&args[0]))