view.result:

  Fixed the results of a test for group_concat.
  After the fix foor bug #11639 the results became
  correct.
olap.result, olap.test:
  Added a test case for bug #11639.
sql_select.cc:
  Fixed bug #11639: a wrong result set when using a view
  instead of the underlying table in a rollup query 
  executed through filesort.
  The old code did not take into account that we always
  use an Item_ref object when referring to a view column.
item.h:
  Fixed bug #11639.
  Now if two Item_ref items ref1 and ref2 refer to the same field
  then ref1->eq(ref2) returns 1.


sql/item.h:
  Fixed bug #11639.
  Now if two Item_ref items ref1 and ref2 refer to the same field
  then ref1->eq(ref2) returns 1.
sql/sql_select.cc:
  Fixed bug #11639: a wrong result set when using a view
  instead of the underlying table in a rollup query 
  executed through filesort.
  The old code did not take into account that we always
  use an Item_ref object when referring to a view column.
mysql-test/t/olap.test:
  Added a test case for bug #11639.
mysql-test/r/olap.result:
  Added a test case for bug #11639.
mysql-test/r/view.result:
  Fixed the results of a test for group_concat.
  After the fix foor bug #11639 the results became
  correct.

mysql-test/r/olap.result

@@ -555,3 +555,25 @@ IFNULL(a, 'TEST')	COALESCE(b, 'TEST')
 4	TEST
 TEST	TEST
 DROP TABLE t1,t2;
+CREATE TABLE t1(id int, type char(1));
+INSERT INTO t1 VALUES
+(1,"A"),(2,"C"),(3,"A"),(4,"A"),(5,"B"),
+(6,"B"),(7,"A"),(8,"C"),(9,"A"),(10,"C");
+CREATE VIEW v1 AS SELECT * FROM t1;
+SELECT type FROM t1 GROUP BY type WITH ROLLUP;
+type
+A
+B
+C
+NULL
+SELECT type FROM v1 GROUP BY type WITH ROLLUP;
+type
+A
+B
+C
+NULL
+EXPLAIN SELECT type FROM v1 GROUP BY type WITH ROLLUP;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	10	Using filesort
+DROP VIEW v1;
+DROP TABLE t1;

mysql-test/r/view.result

@@ -1561,7 +1561,7 @@ one	1025,2025,3025
 two	1050,1050
 select col1,group_concat(col2,col3) from v1 group by col1;
 col1	group_concat(col2,col3)
-two	1025,2025,3025
+one	1025,2025,3025
 two	1050,1050
 drop view v1;
 drop table t1;

mysql-test/t/olap.test

@@ -250,3 +250,19 @@ SELECT IFNULL(a, 'TEST'), COALESCE(b, 'TEST') FROM t2
 
 DROP TABLE t1,t2;
 
+#
+# Tests for bug #11639: ROLLUP over view executed through filesort
+#
+
+CREATE TABLE t1(id int, type char(1));
+INSERT INTO t1 VALUES
+  (1,"A"),(2,"C"),(3,"A"),(4,"A"),(5,"B"),
+  (6,"B"),(7,"A"),(8,"C"),(9,"A"),(10,"C");
+CREATE VIEW v1 AS SELECT * FROM t1;
+
+SELECT type FROM t1 GROUP BY type WITH ROLLUP;
+SELECT type FROM v1 GROUP BY type WITH ROLLUP;
+EXPLAIN SELECT type FROM v1 GROUP BY type WITH ROLLUP;
+
+DROP VIEW v1;
+DROP TABLE t1;

sql/item.h

@@ -1340,7 +1340,10 @@ class Item_ref :public Item_ident
   Item_ref(THD *thd, Item_ref *item) :Item_ident(thd, item), result_field(item->result_field), ref(item->ref) {}
   enum Type type() const		{ return REF_ITEM; }
   bool eq(const Item *item, bool binary_cmp) const
-  { return ref && (*ref)->eq(item, binary_cmp); }
+  { 
+    Item *it= ((Item *) item)->real_item();
+    return ref && (*ref)->eq(it, binary_cmp);
+  }
   double val_real();
   longlong val_int();
   my_decimal *val_decimal(my_decimal *);

sql/sql_select.cc

@@ -12150,7 +12150,7 @@ count_field_types(TMP_TABLE_PARAM *param, List<Item> &fields,
   param->quick_group=1;
   while ((field=li++))
   {
-    Item::Type type=field->type();
+    Item::Type type=field->real_item()->type();
     if (type == Item::FIELD_ITEM)
       param->field_count++;
     else if (type == Item::SUM_FUNC_ITEM)
@@ -12164,7 +12164,7 @@ count_field_types(TMP_TABLE_PARAM *param, List<Item> &fields,
 
 	for (uint i=0 ; i < sum_item->arg_count ; i++)
 	{
-	  if (sum_item->args[0]->type() == Item::FIELD_ITEM)
+	  if (sum_item->args[0]->real_item()->type() == Item::FIELD_ITEM)
 	    param->field_count++;
 	  else
 	    param->func_count++;
@@ -12411,9 +12411,10 @@ setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param,
   param->copy_funcs.empty();
   for (i= 0; (pos= li++); i++)
   {
-    if (pos->type() == Item::FIELD_ITEM)
+    if (pos->real_item()->type() == Item::FIELD_ITEM)
     {
       Item_field *item;
+      pos= pos->real_item();
       if (!(item= new Item_field(thd, ((Item_field*) pos))))
 	goto err;
       pos= item;