LP:780386 - Incorrect result of NULL <op> ALL (<empty set>)

The following query:

SELECT a1.f3 AS r FROM t2 AS a1 , t1 WHERE a1.f3 < ALL ( SELECT f3 FROM t3 WHERE f3 = 1 ) ;

returns 1 row for which a1.f3 = NULL with join_cache_level = 0 and 2 rows with join_cache_level = 3 . maria-5.1 returns 2 rows. Notice that the subquery returns an empty result.

Note that the server reports that NULL < ALL ( SELECT f3 FROM t3 WHERE 0 ) is TRUE

test case:

DROP TABLE IF EXISTS t1;
CREATE TABLE t1 ( f11 int) ;
INSERT IGNORE INTO t1 VALUES (0),(0);

CREATE TABLE t2 ( f3 int, f10 int, KEY (f10,f3)) ;
INSERT IGNORE INTO t2 VALUES (0,0),(98,0),(6,0),(5,0),(0,0),(3,0),(1,0),(1,0),(147,0),(3,0),(3,0),(NULL,NULL),(2,0),(1,0),(8,0),(8,0),(8,0),(0,0),(1,0),(8,0),(5,0);

DROP TABLE IF EXISTS t3;
CREATE TABLE t3 ( f3 int) ;
INSERT INTO t3 VALUES (0),(0);

--let $query = SELECT a1.f3 AS r FROM t2 AS a1 , t1 WHERE a1.f3 < ALL ( SELECT f3 FROM t3 WHERE f3 = 1 ) ;

SET SESSION join_cache_level = 0;
--eval CREATE TABLE r1 AS $query ;
SET SESSION join_cache_level = 3;
--eval CREATE TABLE r2 AS $query ;

SELECT COUNT FROM r1 WHERE r IS NULL;
SELECT COUNT FROM r2 WHERE r IS NULL;