1 files changed, 51 insertions, 0 deletions
diff --git a/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test
index 14b62bfd2f7..37f660d6682 100644
--- a/mysql-test/t/subselect4.test
+++ b/mysql-test/t/subselect4.test
@@ -1778,6 +1778,57 @@ drop table t1, t2;
 set optimizer_switch=@subselect4_tmp;
 
 --echo #
+--echo # MDEV-3928  Assertion `example' failed in Item_cache::is_expensive_processor with a 2-level IN subquery 
+--echo #
+
+CREATE TABLE t1 (a1 INT, b1 TIME) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (4,'21:22:34'),(6,'10:50:38');
+
+CREATE TABLE t2 (a2 INT, b2 TIME) ENGINE=MyISAM;
+INSERT INTO t2 VALUES (8, '06:17:39');
+
+CREATE TABLE t3 (a3 INT, b3 TIME) ENGINE=MyISAM;
+INSERT INTO t3 VALUES (1,'00:00:01'),(7,'00:00:02');
+
+EXPLAIN
+SELECT * FROM t1 WHERE a1 IN ( 
+  SELECT a2 FROM t2 WHERE a2 IN ( 
+    SELECT a3 FROM t3 WHERE b2 = b1 AND b2 <= b1 ORDER BY b3 
+  )
+);
+
+SELECT * FROM t1 WHERE a1 IN ( 
+  SELECT a2 FROM t2 WHERE a2 IN ( 
+    SELECT a3 FROM t3 WHERE b2 = b1 AND b2 <= b1 ORDER BY b3 
+  )
+);
+drop table t1, t2, t3;
+
+--echo #
+--echo # MDEV-4056:Server crashes in Item_func_trig_cond::val_int
+--echo # with FROM and NOT IN subqueries, LEFT JOIN, derived_merge+in_to_exists
+--echo #
+
+set @optimizer_switch_MDEV4056 = @@optimizer_switch;
+SET optimizer_switch = 'derived_merge=on,in_to_exists=on';
+
+CREATE TABLE t1 (a VARCHAR(1)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('x'),('d');
+
+CREATE TABLE t2 (pk INT PRIMARY KEY, b INT, c VARCHAR(1))  ENGINE=MyISAM;
+INSERT INTO t2 VALUES (1,2,'v'),(2,150,'v');
+
+SELECT * FROM t1 LEFT JOIN (  
+  SELECT * FROM t2 WHERE ( pk, pk ) NOT IN ( 
+    SELECT MIN(b), SUM(pk) FROM t1
+  ) 
+) AS alias1 ON (a = c) 
+WHERE b IS NULL OR a < 'u';
+
+drop table t1,t2;
+set @@optimizer_switch = @optimizer_switch_MDEV4056;
+
+--echo #
 --echo # MDEV-3899  Valgrind warnings (blocks are definitely lost) in filesort on IN subquery with SUM and DISTINCT
 --echo #