diff --git a/mysql-test/r/select.result b/mysql-test/r/select.result
index 3aae29a922e..335637b787f 100644
--- a/mysql-test/r/select.result
+++ b/mysql-test/r/select.result
@@ -3427,3 +3427,22 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	A	range	PRIMARY	PRIMARY	12	NULL	3	Using where
 1	SIMPLE	B	ref	PRIMARY	PRIMARY	8	const,test.A.e	10	
 drop table t1, t2;
+CREATE TABLE t1 (a int PRIMARY KEY, b int, INDEX(b));
+INSERT INTO t1 VALUES (1, 3), (9,4), (7,5), (4,5), (6,2),
+(3,1), (5,1), (8,9), (2,2), (0,9);
+CREATE TABLE t2 (c int, d int, f int, INDEX(c,f));
+INSERT INTO t2 VALUES
+(1,0,0), (1,0,1), (2,0,0), (2,0,1), (3,0,0), (4,0,1),
+(5,0,0), (5,0,1), (6,0,0), (0,0,1), (7,0,0), (7,0,1),
+(0,0,0), (0,0,1), (8,0,0), (8,0,1), (9,0,0), (9,0,1);
+EXPLAIN
+SELECT a, c, d, f FROM t1,t2 WHERE a=c AND b BETWEEN 4 AND 6;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	PRIMARY,b	b	5	NULL	3	Using where
+1	SIMPLE	t2	ref	c	c	5	test.t1.a	2	Using where
+EXPLAIN
+SELECT a, c, d, f FROM t1,t2 WHERE a=c AND b BETWEEN 4 AND 6 AND a > 0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	PRIMARY,b	b	5	NULL	3	Using where
+1	SIMPLE	t2	ref	c	c	5	test.t1.a	2	Using where
+DROP TABLE t1, t2;
diff --git a/mysql-test/t/select.test b/mysql-test/t/select.test
index 033350d138a..4b6ae921b9b 100644
--- a/mysql-test/t/select.test
+++ b/mysql-test/t/select.test
@@ -2899,3 +2899,24 @@ select 'In next EXPLAIN, B.rows must be exactly 10:' Z;
 explain select * from t2 A, t2 B where A.a=5 and A.b=5 and A.C<5
           and B.a=5 and B.b=A.e and (B.b =1 or B.b = 3 or B.b=5);
 drop table t1, t2;
+
+#
+#Bug #18940: selection of optimal execution plan caused by equality
+#            propagation (the bug was fixed by the patch for bug #17379)
+
+CREATE TABLE t1 (a int PRIMARY KEY, b int, INDEX(b));
+INSERT INTO t1 VALUES (1, 3), (9,4), (7,5), (4,5), (6,2),
+                      (3,1), (5,1), (8,9), (2,2), (0,9);
+
+CREATE TABLE t2 (c int, d int, f int, INDEX(c,f));
+INSERT INTO t2 VALUES
+ (1,0,0), (1,0,1), (2,0,0), (2,0,1), (3,0,0), (4,0,1),
+ (5,0,0), (5,0,1), (6,0,0), (0,0,1), (7,0,0), (7,0,1),
+ (0,0,0), (0,0,1), (8,0,0), (8,0,1), (9,0,0), (9,0,1);
+
+EXPLAIN
+SELECT a, c, d, f FROM t1,t2 WHERE a=c AND b BETWEEN 4 AND 6;
+EXPLAIN
+SELECT a, c, d, f FROM t1,t2 WHERE a=c AND b BETWEEN 4 AND 6 AND a > 0;
+
+DROP TABLE t1, t2;