item_func.h, item_func.cc, sql_select.cc, item.h:

  Post review changes for bug#19862.


sql/sql_select.cc:
  Post review changes for bug#19862.
sql/item_func.h:
  Post review changes for bug#19862.
sql/item_func.cc:
  Post review changes for bug#19862.
sql/item.h:
  Post review changes for bug#19862.

sql/item.h

@@ -752,7 +752,7 @@ public:
   virtual bool find_item_in_field_list_processor(byte *arg) { return 0; }
   virtual bool change_context_processor(byte *context) { return 0; }
   virtual bool reset_query_id_processor(byte *query_id) { return 0; }
-  virtual bool func_type_checker_processor(byte *arg) { return 0; }
+  virtual bool is_expensive_processor(byte *arg) { return 0; }
 
   virtual Item *equal_fields_propagator(byte * arg) { return this; }
   virtual Item *set_no_const_sub(byte *arg) { return this; }

sql/item_func.cc

@@ -399,9 +399,9 @@ Field *Item_func::tmp_table_field(TABLE *t_arg)
 }
 
 
-bool Item_func::func_type_checker_processor(byte *arg)
+bool Item_func::is_expensive_processor(byte *arg)
 {
-  return *((Functype*)arg) == functype();
+  return is_expensive();
 }
 
 

sql/item_func.h

@@ -189,7 +189,8 @@ public:
   Item *transform(Item_transformer transformer, byte *arg);
   void traverse_cond(Cond_traverser traverser,
                      void * arg, traverse_order order);
-  bool func_type_checker_processor(byte *arg);
+  bool is_expensive_processor(byte *arg);
+  virtual bool is_expensive() { return 0; }
 };
 
 
@@ -947,6 +948,7 @@ public:
   void cleanup();
   Item_result result_type () const { return udf.result_type(); }
   table_map not_null_tables() const { return 0; }
+  bool is_expensive() { return 1; }
 };
 
 
@@ -1475,6 +1477,7 @@ public:
   virtual enum Functype functype() const { return FUNC_SP; }
 
   bool fix_fields(THD *thd, Item **ref);
+  bool is_expensive() { return 1; }
 };
 
 

sql/sql_select.cc

@@ -1073,10 +1073,7 @@ JOIN::optimize()
       for (ORDER *tmp_order= order; tmp_order ; tmp_order=tmp_order->next)
       {
         Item *item= *tmp_order->item;
-        Item_func::Functype type=Item_func::FUNC_SP;
-        Item_func::Functype type1=Item_func::UDF_FUNC;
-        if (item->walk(&Item::func_type_checker_processor,(byte*)&type) ||
-            item->walk(&Item::func_type_checker_processor,(byte*)&type1))
+        if (item->walk(&Item::is_expensive_processor,(byte*)0))
         {
           /* Force tmp table without sort */
           need_tmp=1; simple_order=simple_group=0;