Merge may.pils.ru:/home/svoj/devel/mysql/BUG20357/mysql-4.1

into  may.pils.ru:/home/svoj/devel/mysql/BUG20357/mysql-5.0

mysql-test/r/myisam.result

@@ -747,6 +747,19 @@ 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';

mysql-test/t/myisam.test

@@ -697,6 +697,18 @@ select count(*)   from t1 where id2 = 10;
 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
 #

sql/opt_sum.cc

@@ -701,6 +701,12 @@ 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 ;