Merge with 4.1

BitKeeper/etc/logging_ok:
  auto-union
client/mysqltest.c:
  Auto merged
configure.in:
  Auto merged
include/my_global.h:
  Auto merged
mysql-test/r/bdb.result:
  Auto merged
mysql-test/r/connect.result:
  Auto merged
mysql-test/r/multi_update.result:
  Auto merged
mysql-test/r/show_check.result:
  Auto merged
mysql-test/r/system_mysql_db.result:
  Auto merged
mysql-test/t/multi_update.test:
  Auto merged
sql/ha_berkeley.cc:
  Auto merged
sql/ha_berkeley.h:
  Auto merged
sql/ha_heap.h:
  Auto merged
sql/ha_innodb.h:
  Auto merged
sql/handler.h:
  Auto merged
sql/item_cmpfunc.cc:
  Auto merged
sql/log.cc:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/mysqld.cc:
  Auto merged
sql/set_var.cc:
  Auto merged
sql/sql_acl.cc:
  Auto merged
sql/sql_class.cc:
  Auto merged
sql/sql_db.cc:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_show.cc:
  Auto merged
sql/sql_table.cc:
  Auto merged
sql/sql_update.cc:
  Auto merged
sql/sql_yacc.yy:
  Auto merged
sql/opt_range.cc:
  Merge with 4.1
  true -> TRUE and false -> FALSE

sql/sql_class.cc

@@ -549,21 +549,23 @@ bool THD::convert_string(String *s, CHARSET_INFO *from_cs, CHARSET_INFO *to_cs)
   return FALSE;
 }
 
+
 /*
   Update some cache variables when character set changes
 */
 
 void THD::update_charset()
 {
-  charset_is_system_charset= my_charset_same(charset(),system_charset_info);
-  charset_is_collation_connection= my_charset_same(charset(),
-						   variables.
-						   collation_connection);
+  uint32 not_used;
+  charset_is_system_charset= !String::needs_conversion(0,charset(),
+                                                       system_charset_info,
+                                                       &not_used);
+  charset_is_collation_connection= 
+    !String::needs_conversion(0,charset(),variables.collation_connection,
+                              &not_used);
 }
 
 
-
-
 /* routings to adding tables to list of changed in transaction tables */
 
 inline static void list_include(CHANGED_TABLE_LIST** prev,