Merge sunlight.local:/local_work/tmp_merge-5.0-opt-mysql

into  sunlight.local:/local_work/tmp_merge-5.1-opt-mysql


client/mysql.cc:
  Auto merged
mysql-test/r/date_formats.result:
  Auto merged
mysql-test/r/func_gconcat.result:
  Auto merged
mysql-test/r/func_group.result:
  Auto merged
mysql-test/r/func_str.result:
  Auto merged
mysql-test/r/group_min_max.result:
  Auto merged
BitKeeper/deleted/.del-make_win_src_distribution.sh~f80d8fca44e4e5f1:
  Auto merged
BitKeeper/deleted/.del-mysqld.dsp~ffdbf2d234e23e56:
  Auto merged
BitKeeper/deleted/.del-mysqld_ia64.dsp~7f8cf84d81ee04e2:
  Auto merged
BitKeeper/deleted/.del-mysqldump.dsp~a8bd23547d3fc27e:
  Auto merged
BitKeeper/deleted/.del-mysqldump_ia64.dsp~a2aabe898be35b31:
  Auto merged
mysql-test/r/innodb.result:
  Auto merged
mysql-test/r/innodb_mysql.result:
  Auto merged
mysql-test/r/ps_7ndb.result:
  Auto merged
mysql-test/r/type_ranges.result:
  Auto merged
mysql-test/r/udf.result:
  Auto merged
mysql-test/r/union.result:
  Auto merged
mysql-test/r/view.result:
  Auto merged
mysql-test/t/date_formats.test:
  Auto merged
mysql-test/t/func_gconcat.test:
  Auto merged
mysql-test/t/func_group.test:
  Auto merged
mysql-test/t/group_min_max.test:
  Auto merged
mysql-test/t/innodb.test:
  Auto merged
mysql-test/t/innodb_mysql.test:
  Auto merged
mysql-test/t/mysql.test:
  Auto merged
mysql-test/t/select.test:
  Auto merged
mysql-test/t/sp.test:
  Auto merged
mysql-test/t/view.test:
  Auto merged
sql/field.cc:
  Auto merged
sql/item_cmpfunc.cc:
  Auto merged
sql/item_cmpfunc.h:
  Auto merged
sql/item_func.cc:
  Auto merged
sql/item_func.h:
  Auto merged
sql/item_strfunc.cc:
  Auto merged
sql/item_subselect.cc:
  Auto merged
sql/item_subselect.h:
  Auto merged
sql/opt_range.h:
  Auto merged
sql/sql_base.cc:
  Auto merged
sql/sql_class.cc:
  Auto merged
sql/sql_insert.cc:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_show.cc:
  Auto merged
sql/sql_yacc.yy:
  Auto merged
sql/time.cc:
  Auto merged
storage/ndb/test/ndbapi/Makefile.am:
  Auto merged
strings/decimal.c:
  Auto merged
mysql-test/r/analyse.result:
  Manual merge
mysql-test/r/bigint.result:
  Manual merge
mysql-test/r/create.result:
  Manual merge
mysql-test/r/information_schema.result:
  Manual merge
mysql-test/r/ps_2myisam.result:
  Manual merge
mysql-test/r/ps_3innodb.result:
  Manual merge
mysql-test/r/ps_4heap.result:
  Manual merge
mysql-test/r/ps_5merge.result:
  Manual merge
mysql-test/r/ps_6bdb.result:
  Manual merge
mysql-test/r/rpl_insert_id.result:
  Manual merge
mysql-test/r/select.result:
  Manual merge
mysql-test/r/sp.result:
  Manual merge
mysql-test/r/subselect.result:
  Manual merge
mysql-test/t/information_schema.test:
  Manual merge
mysql-test/t/rpl_insert_id.test:
  Manual merge
sql/field.h:
  Manual merge
sql/item.cc:
  Manual merge
sql/item.h:
  Manual merge
sql/item_strfunc.h:
  Manual merge
sql/item_sum.cc:
  Manual merge
sql/mysql_priv.h:
  Manual merge
sql/share/errmsg.txt:
  Manual merge
sql/sql_class.h:
  Manual merge
sql/sql_select.cc:
  Manual merge

1 files changed, 10 insertions, 2 deletions

diff --git a/sql/item.h b/sql/item.h
index be25d51bea1..0e62d2aa9f0 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -737,9 +737,16 @@ public:
     Any new item which can be NULL must implement this call.
   */
   virtual bool is_null() { return 0; }
+
   /*
-    it is "top level" item of WHERE clause and we do not need correct NULL
-    handling
+    Inform the item that there will be no distinction between its result
+    being FALSE or NULL.
+
+    NOTE
+      This function will be called for eg. Items that are top-level AND-parts
+      of the WHERE clause. Items implementing this function (currently
+      Item_cond_and and subquery-related item) enable special optimizations
+      when they are "top level".
   */
   virtual void top_level_item() {}
   /*
@@ -784,6 +791,7 @@ public:
   virtual bool collect_item_field_processor(byte * arg) { return 0; }
   virtual bool find_item_in_field_list_processor(byte *arg) { return 0; }
   virtual bool change_context_processor(byte *context) { return 0; }
+  virtual bool is_expensive_processor(byte *arg) { return 0; }
   virtual bool register_field_in_read_map(byte *arg) { return 0; }
   /*
     Check if a partition function is allowed