3 files changed, 31 insertions, 0 deletions
diff --git a/mysql-test/r/myisam.result b/mysql-test/r/myisam.result
index 7aaf3c8f85a..cd1bc5c34e8 100644
--- a/mysql-test/r/myisam.result
+++ b/mysql-test/r/myisam.result
@@ -748,6 +748,19 @@ select count(id1) from t1 where id2 = 10;
 count(id1)
 5
 drop table t1;
+CREATE TABLE t1(a TINYINT, KEY(a)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES(1);
+SELECT MAX(a) FROM t1 IGNORE INDEX(a);
+MAX(a)
+1
+ALTER TABLE t1 DISABLE KEYS;
+SELECT MAX(a) FROM t1;
+MAX(a)
+1
+SELECT MAX(a) FROM t1 IGNORE INDEX(a);
+MAX(a)
+1
+DROP TABLE t1;
 CREATE TABLE t1(a CHAR(9), b VARCHAR(7)) ENGINE=MyISAM;
 INSERT INTO t1(a) VALUES('xxxxxxxxx'),('xxxxxxxxx');
 UPDATE t1 AS ta1,t1 AS ta2 SET ta1.b='aaaaaa',ta2.b='bbbbbb';
diff --git a/mysql-test/t/myisam.test b/mysql-test/t/myisam.test
index 5f948973141..ca49db40ae4 100644
--- a/mysql-test/t/myisam.test
+++ b/mysql-test/t/myisam.test
@@ -706,6 +706,18 @@ select count(id1) from t1 where id2 = 10;
 drop table t1;
 
 #
+# BUG##20357 - Got error 124 from storage engine using MIN and MAX functions
+#              in queries
+#
+CREATE TABLE t1(a TINYINT, KEY(a)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES(1);
+SELECT MAX(a) FROM t1 IGNORE INDEX(a);
+ALTER TABLE t1 DISABLE KEYS;
+SELECT MAX(a) FROM t1;
+SELECT MAX(a) FROM t1 IGNORE INDEX(a);
+DROP TABLE t1;
+
+#
 # BUG#18036 - update of table joined to self reports table as crashed
 #
 CREATE TABLE t1(a CHAR(9), b VARCHAR(7)) ENGINE=MyISAM;
diff --git a/sql/opt_sum.cc b/sql/opt_sum.cc
index 97e271121d3..b53fbfd3f80 100644
--- a/sql/opt_sum.cc
+++ b/sql/opt_sum.cc
@@ -676,6 +676,12 @@ static bool find_key_for_maxmin(bool max_fl, TABLE_REF *ref,
   {
     KEY_PART_INFO *part,*part_end;
     key_part_map key_part_to_use= 0;
+    /*
+      Perform a check if index is not disabled by ALTER TABLE
+      or IGNORE INDEX.
+    */
+    if (!table->keys_in_use_for_query.is_set(idx))
+      continue;
     uint jdx= 0;
     *prefix_len= 0;
     for (part= keyinfo->key_part, part_end= part+keyinfo->key_parts ;