item_cmpfunc.cc, func_in.result, func_in.test:

  Reverted fix for bug#18360


mysql-test/t/func_in.test:
  Reverted fix for bug#18360
mysql-test/r/func_in.result:
  Reverted fix for bug#18360
sql/item_cmpfunc.cc:
  Reverted fix for bug#18360

mysql-test/r/func_in.result

@@ -202,24 +202,3 @@ select count(*) from t1 where id not in (1,2);
 count(*)
 1
 drop table t1;
-create table t1 (f1 char(1), f2 int);
-insert into t1 values (1,0),('a',1),('z',2);
-select f1 from t1 where f1 in (1,'z');
-f1
-1
-z
-select f2 from t1 where f2 in (1,'z');
-f2
-0
-1
-select f1 from t1 where 'z' in (1,f1);
-f1
-z
-select * from t1 where 'z' in (f2,f1);
-f1	f2
-z	2
-select * from t1 where 1 in (f2,f1);
-f1	f2
-1	0
-a	1
-drop table t1;

mysql-test/t/func_in.test

@@ -109,16 +109,4 @@ select count(*) from t1 where id not in (1);
 select count(*) from t1 where id not in (1,2);
 drop table t1;
 
-#
-# Bug#18360 Incorrect type coercion in IN() results in false comparison
-#
-create table t1 (f1 char(1), f2 int);
-insert into t1 values (1,0),('a',1),('z',2);
-select f1 from t1 where f1 in (1,'z');
-select f2 from t1 where f2 in (1,'z');
-select f1 from t1 where 'z' in (1,f1);
-select * from t1 where 'z' in (f2,f1);
-select * from t1 where 1 in (f2,f1);
-drop table t1;
-
 # End of 4.1 tests

sql/item_cmpfunc.cc

@@ -78,9 +78,6 @@ static void agg_result_type(Item_result *type, Item **items, uint nitems)
 
   NOTES
     Aggregation rules:
-    If all items are constants the type will be aggregated from all items.
-    If there are some non-constant items then only types of non-constant
-    items will be used for aggregation.
     If there are DATE/TIME fields/functions in the list and no string
     fields/functions in the list then:
       The INT_RESULT type will be used for aggregation instead of original
@@ -167,34 +164,25 @@ static void agg_cmp_type(THD *thd, Item_result *type, Item **items, uint nitems)
       }
     }
   }
-  /* Reset to 0 on first occurence of non-const item. 1 otherwise */
-  bool is_const= items[0]->const_item();
   /*
     If the first item is a date/time function then its result should be
     compared as int
   */
   if (field)
-  {
-    /* Suppose we are comparing dates and some non-constant items are present. */
+    /* Suppose we are comparing dates */
     type[0]= INT_RESULT;
-    is_const= 0;
-  }
   else
     type[0]= items[0]->result_type();
 
   for (i= 0; i < nitems ; i++)
   {
-    if (!items[i]->const_item())
-    {
-      Item_result result= field && items[i]->result_as_longlong() ?
-                            INT_RESULT : items[i]->result_type();
-      type[0]= is_const ? result : item_cmp_type(type[0], result);
-      is_const= 0;
-    }
-    else if (is_const)
-      type[0]= item_cmp_type(type[0], items[i]->result_type());
-    else if (field)
-      convert_constant_item(thd, field, &items[i]);
+    Item_result result= items[i]->result_type();
+    if (field &&
+         ((!items[i]->const_item() && items[i]->result_as_longlong()) ||
+         (items[i]->const_item() && convert_constant_item(thd, field,
+                                                          &items[i]))))
+      result= INT_RESULT;
+    type[0]= item_cmp_type(type[0], result);
   }
 
   if (res == Item::FUNC_ITEM && field)