Merge bk-internal.mysql.com:/home/bk/mysql-4.1

into  mysql.com:/opt/local/work/mysql-4.1-11458

7 files changed, 21 insertions, 34 deletions

diff --git a/sql/item.cc b/sql/item.cc
index 3bdaf856f2a..19b88c115b9 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -889,6 +889,7 @@ void Item_param::set_null()
   max_length= 0;
   decimals= 0;
   state= NULL_VALUE;
+  item_type= Item::NULL_ITEM;
   DBUG_VOID_RETURN;
 }
 
@@ -1339,34 +1340,6 @@ bool Item_param::convert_str_value(THD *thd)
   return rc;
 }
 
-bool Item_param::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
-{
-  DBUG_ASSERT(fixed == 0);
-  SELECT_LEX *cursel= (SELECT_LEX *) thd->lex->current_select;
-
-  /*
-    Parameters in a subselect should mark the subselect as not constant
-    during prepare
-  */
-  if (state == NO_VALUE)
-  {
-    /*
-      SELECT_LEX_UNIT::item set only for subqueries, so test of it presence
-      can be barrier to stop before derived table SELECT or very outer SELECT
-    */
-    for(;
-        cursel->master_unit()->item;
-        cursel= cursel->outer_select())
-    {
-      Item_subselect *subselect_item= cursel->master_unit()->item;
-      subselect_item->used_tables_cache|= OUTER_REF_TABLE_BIT;
-      subselect_item->const_item_cache= 0;
-    }
-  }
-  fixed= 1;
-  return 0;
-}
-
 
 bool Item_param::basic_const_item() const
 {
diff --git a/sql/item.h b/sql/item.h
index 8de2adeb730..a8b0bfe9512 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -564,7 +564,6 @@ public:
   bool get_time(TIME *tm);
   bool get_date(TIME *tm, uint fuzzydate);
   int  save_in_field(Field *field, bool no_conversions);
-  bool fix_fields(THD *, struct st_table_list *, Item **);
 
   void set_null();
   void set_int(longlong i, uint32 max_length_arg);
diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index 20ba838e61c..dec32398a80 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -119,7 +119,6 @@ public:
   friend class Item_in_optimizer;
   friend bool Item_field::fix_fields(THD *, TABLE_LIST *, Item **);
   friend bool Item_ref::fix_fields(THD *, TABLE_LIST *, Item **);
-  friend bool Item_param::fix_fields(THD *, TABLE_LIST *, Item **);
 };
 
 /* single value subselect */
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 5c97269b5ce..722b76796b2 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -251,6 +251,8 @@ extern CHARSET_INFO *national_charset_info, *table_alias_charset;
 #define UNCACHEABLE_SIDEEFFECT	4
 // forcing to save JOIN for explain
 #define UNCACHEABLE_EXPLAIN     8
+/* Don't evaluate subqueries in prepare even if they're not correlated */
+#define UNCACHEABLE_PREPARE    16
 
 #ifdef EXTRA_DEBUG
 /*
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index 927982e444f..07b5c9d8edf 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -257,6 +257,7 @@ public:
       UNCACHEABLE_RAND
       UNCACHEABLE_SIDEEFFECT
       UNCACHEABLE_EXPLAIN
+      UNCACHEABLE_PREPARE
   */
   uint8 uncacheable;
   enum sub_select_type linkage;
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index d7fd3239df5..dc55a842263 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -4123,6 +4123,14 @@ mysql_new_select(LEX *lex, bool move_down)
   select_lex->select_number= ++lex->thd->select_number;
   select_lex->init_query();
   select_lex->init_select();
+  /*
+    Don't evaluate this subquery during statement prepare even if
+    it's a constant one. The flag is switched off in the end of
+    mysql_stmt_prepare.
+  */
+  if (lex->thd->current_arena->is_stmt_prepare())
+    select_lex->uncacheable|= UNCACHEABLE_PREPARE;
+
   if (move_down)
   {
     lex->subqueries= TRUE;
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index 9e2612c5661..f7e2bd0467e 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -1657,13 +1657,18 @@ int mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
   {
     stmt->setup_set_params();
     SELECT_LEX *sl= stmt->lex->all_selects_list;
-    /*
-      Save WHERE clause pointers, because they may be changed during query
-      optimisation.
-    */
     for (; sl; sl= sl->next_select_in_list())
     {
+      /*
+        Save WHERE clause pointers, because they may be changed
+        during query optimisation.
+      */
       sl->prep_where= sl->where;
+      /*
+        Switch off a temporary flag that prevents evaluation of
+        subqueries in statement prepare.
+      */
+      sl->uncacheable&= ~UNCACHEABLE_PREPARE;
     }
     stmt->state= Item_arena::PREPARED;
   }