Fix for prepared statements

Here i added Item_*::cleanup() functions,
removed a lot of ~Item_*'s,
added code to restore order_list and group_list


sql/item.cc:
  cleanups methods implemented
  Item_ref constructors changed
sql/item.h:
  cleanups declared
  Item_ref constructors changed
  some ~Item_* deleted
sql/item_cmpfunc.cc:
  new Item_ref format
sql/item_cmpfunc.h:
  saving/restoring of the original arguments added to
  eq and equal functions
sql/item_func.cc:
  New Item_ref format
sql/item_func.h:
  destructors removed/changed to 'cleanup()'
sql/item_row.cc:
  New Item_ref format
sql/item_row.h:
  ~Item_row -> cleanup()
sql/item_strfunc.cc:
  new Item_ref format
sql/item_strfunc.h:
  destructors removed
sql/item_subselect.cc:
  Item_subselect implementation,
  new Item_ref() format
sql/item_subselect.h:
  cleanups for subselects declared
sql/item_sum.cc:
  cleanups implementations
sql/item_sum.h:
  cleanups declarations
  destructors removed
sql/mysql_priv.h:
  free_items, cleanup_items exported
sql/sql_prepare.cc:
  cleanup_items, free_items calls added
  stmt->query_id= thd->query_id restored
  cleanup procedures for group_list and order_list added
sql/sql_yacc.yy:
  New Item_ref() format

1 files changed, 10 insertions, 0 deletions

diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index 8444dc7bf66..dc3d07540da 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -69,6 +69,7 @@ public:
 		     select_subselect *result);
 
   ~Item_subselect();
+  void cleanup();
   virtual void reset() 
   {
     null_value= 1;
@@ -199,6 +200,13 @@ public:
      
   {}
 
+  void cleanup()
+  {
+    Item_exists_subselect::cleanup();
+    abort_on_null= 0;
+    transformed= 0;
+    upper_not= 0;
+  }
   subs_type substype() { return IN_SUBS; }
   void reset() 
   {
@@ -261,6 +269,7 @@ public:
     maybe_null= 0;
   }
   virtual ~subselect_engine() {}; // to satisfy compiler
+  virtual void cleanup() {}
   
   // set_thd should be called before prepare()
   void set_thd(THD *thd_arg) { thd= thd_arg; }
@@ -290,6 +299,7 @@ public:
   subselect_single_select_engine(st_select_lex *select,
 				 select_subselect *result,
 				 Item_subselect *item);
+  void cleanup();
   int prepare();
   void fix_length_and_dec(Item_cache** row);
   int exec();