MWL#89: Cost-based choice between Materialization and IN->EXISTS transformation

Merge 5.3-mwl89 into 5.3 main.

There is one remaining test failure in this merge:
innodb_mysql_lock2. All other tests have been checked to
deliver the same results/explains as 5.3-mwl89, including
the few remaining wrong results.

1 files changed, 2 insertions, 0 deletions

diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index cd408ac723f..ef3713977df 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -2656,6 +2656,7 @@ void Query_arena::free_items()
   for (; free_list; free_list= next)
   {
     next= free_list->next;
+    DBUG_ASSERT(free_list != next);
     free_list->delete_self();
   }
   /* Postcondition: free_list is 0 */
@@ -3092,6 +3093,7 @@ void TMP_TABLE_PARAM::init()
   table_charset= 0;
   precomputed_group_by= 0;
   bit_fields_as_long= 0;
+  materialized_subquery= 0;
   skip_create_table= 0;
   DBUG_VOID_RETURN;
 }