Merge with 4.1 to get new thd->mem_root handling

BitKeeper/etc/ignore:
  auto-union
client/mysqldump.c:
  Auto merged
client/mysqltest.c:
  Auto merged
innobase/include/row0mysql.h:
  Auto merged
libmysql/libmysql.c:
  Auto merged
mysql-test/r/ctype_ucs.result:
  Auto merged
mysql-test/r/fulltext.result:
  Auto merged
mysql-test/r/func_in.result:
  Auto merged
mysql-test/r/ps.result:
  Auto merged
mysql-test/r/ps_2myisam.result:
  Auto merged
mysql-test/r/ps_3innodb.result:
  Auto merged
mysql-test/r/ps_4heap.result:
  Auto merged
mysql-test/r/ps_5merge.result:
  Auto merged
mysql-test/r/ps_6bdb.result:
  Auto merged
mysql-test/r/type_float.result:
  Auto merged
mysql-test/r/user_var.result:
  Auto merged
mysql-test/t/innodb.test:
  Auto merged
mysql-test/t/user_var.test:
  Auto merged
mysql-test/t/variables.test:
  Auto merged
sql/ha_berkeley.cc:
  Auto merged
sql/ha_innodb.cc:
  Auto merged
sql/ha_innodb.h:
  Auto merged
sql/ha_ndbcluster.h:
  Auto merged
sql/item.cc:
  Auto merged
sql/item_cmpfunc.cc:
  Auto merged
sql/item_func.cc:
  Auto merged
sql/item_sum.cc:
  Auto merged
sql/item_timefunc.cc:
  Auto merged
sql/log_event.cc:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/mysqld.cc:
  Auto merged
sql/repl_failsafe.cc:
  Auto merged
sql/set_var.cc:
  Auto merged
sql/sql_acl.cc:
  Auto merged
sql/sql_db.cc:
  Auto merged
sql/sql_error.cc:
  Auto merged
sql/sql_help.cc:
  Auto merged
sql/sql_insert.cc:
  Auto merged
sql/sql_prepare.cc:
  Auto merged
sql/sql_select.h:
  Auto merged
sql/sql_yacc.yy:
  Auto merged

1 files changed, 14 insertions, 21 deletions

diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index bafca8acf0f..f426f14a25f 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -190,15 +190,16 @@ bool Item_subselect::fix_fields(THD *thd_param, TABLE_LIST *tables, Item **ref)
 bool Item_subselect::exec()
 {
   int res;
-  MEM_ROOT *old_root= my_pthread_getspecific_ptr(MEM_ROOT*, THR_MALLOC);
-  if (&thd->mem_root != old_root)
-  {
-    my_pthread_setspecific_ptr(THR_MALLOC, &thd->mem_root);
-    res= engine->exec();
-    my_pthread_setspecific_ptr(THR_MALLOC, old_root);
-  }
-  else
-    res= engine->exec();
+  MEM_ROOT *old_root= thd->mem_root;
+
+  /*
+    As this is execution, all objects should be allocated through the main
+    mem root
+  */
+  thd->mem_root= &thd->main_mem_root;
+  res= engine->exec();
+  thd->mem_root= old_root;
+
   if (engine_changed)
   {
     engine_changed= 0;
@@ -661,15 +662,10 @@ Item_in_subselect::single_value_transformer(JOIN *join,
   }
 
   SELECT_LEX *select_lex= join->select_lex;
-  Item_arena *arena= thd->current_arena, backup;
-
+  Item_arena *arena, backup;
+  arena= thd->change_arena_if_needed(&backup);
   thd->where= "scalar IN/ALL/ANY subquery";
 
-  if (arena->is_conventional())
-    arena= 0;                                   // For easier test
-  else
-    thd->set_n_backup_item_arena(arena, &backup);
-
   /*
     Check that the right part of the subselect contains no more than one
     column. E.g. in SELECT 1 IN (SELECT * ..) the right part is (SELECT * ...)
@@ -928,11 +924,8 @@ Item_in_subselect::row_value_transformer(JOIN *join)
   }
   thd->where= "row IN/ALL/ANY subquery";
 
-  Item_arena *arena= thd->current_arena, backup;
-  if (arena->is_conventional())
-    arena= 0;
-  else
-    thd->set_n_backup_item_arena(arena, &backup);
+  Item_arena *arena, backup;
+  arena= thd->change_arena_if_needed(&backup);
 
   if (select_lex->item_list.elements != left_expr->cols())
   {