removed incorrect error message about aggregate functions

improved mechanisn of detection posibility to be NULL for single row queries
switched off substitution optimisation for single row subqueries in PS due to problem in resolving substituted expressions
(changes to make subselects test working with PS protocol)


mysql-test/r/subselect.result:
  removed incorrect error message about aggregate functions
  improved mechanisn of detection posibility to be NULL for single row queries
mysql-test/t/subselect.test:
  removed incorrect error message about aggregate functions
sql/item_subselect.cc:
  removed incorrect error message about aggregate functions
  switched off substitution optimisation for single row subqueries in PS due to problem in resolving substituted expressions
  improved mechanisn of detection posibility to be NULL for single row queries
sql/item_subselect.h:
  new method to help in NULL ability detection

1 files changed, 4 insertions, 0 deletions

diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index f570d89f28f..764c41f33b4 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -291,6 +291,7 @@ public:
   static table_map calc_const_tables(TABLE_LIST *);
   virtual void print(String *str)= 0;
   virtual int change_item(Item_subselect *si, select_subselect *result)= 0;
+  virtual bool no_tables()= 0;
 };
 
 
@@ -315,6 +316,7 @@ public:
   table_map upper_select_const_tables();
   void print (String *str);
   int change_item(Item_subselect *si, select_subselect *result);
+  bool no_tables();
 };
 
 
@@ -335,6 +337,7 @@ public:
   table_map upper_select_const_tables();
   void print (String *str);
   int change_item(Item_subselect *si, select_subselect *result);
+  bool no_tables();
 };
 
 
@@ -364,6 +367,7 @@ public:
   table_map upper_select_const_tables() { return 0; }
   void print (String *str);
   int change_item(Item_subselect *si, select_subselect *result);
+  bool no_tables();
 };