Merge mysql.com:/home/ram/work/mysql-5.1-maint

into  mysql.com:/home/ram/work/b30885/b30885.5.1

mysql-test/r/heap_btree.result

@@ -321,4 +321,12 @@ DROP TABLE t1;
 CREATE TABLE t1 (a INT, UNIQUE USING BTREE(a)) ENGINE=MEMORY;
 INSERT INTO t1 VALUES(NULL),(NULL);
 DROP TABLE t1;
+create table t1(a varchar(255), b varchar(255), 
+key using btree (a,b)) engine=memory;
+insert into t1 values (1, 1), (3, 3), (2, 2), (NULL, 1), (NULL, NULL), (0, 0);
+select * from t1 where a is null;
+a	b
+NULL	NULL
+NULL	1
+drop table t1;
 End of 5.0 tests

mysql-test/t/heap_btree.test

@@ -235,5 +235,14 @@ CREATE TABLE t1 (a INT, UNIQUE USING BTREE(a)) ENGINE=MEMORY;
 INSERT INTO t1 VALUES(NULL),(NULL);
 DROP TABLE t1;
 
+#
+# Bug #30885: MEMORY returns incorrect data if BTREE index is used for NULL lookup
+#
+create table t1(a varchar(255), b varchar(255), 
+                key using btree (a,b)) engine=memory; 
+insert into t1 values (1, 1), (3, 3), (2, 2), (NULL, 1), (NULL, NULL), (0, 0);
+select * from t1 where a is null;
+drop table t1;
+
 --echo End of 5.0 tests