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

into mysql.com:/home/mysql_src/mysql-4.1-clean

mysql-test/r/func_gconcat.result

@@ -457,3 +457,8 @@ group_concat(distinct b order by b)
 Warnings:
 Warning	1260	2 line(s) were cut by GROUP_CONCAT()
 drop table t1;
+CREATE TABLE t1 (id int);
+SELECT GROUP_CONCAT(id) AS gc FROM t1 HAVING gc IS NULL;
+gc
+NULL
+DROP TABLE t1;