Merge 10.1 into 10.2

mysql-test/suite/innodb/r/innodb-index.result

@@ -1567,6 +1567,7 @@ create table t1(f1 int not null, f2 int not null,
 primary key (f1), unique key(f1, f2))engine=innodb;
 insert into t1 values(1,3), (2,2);
 alter table t1 drop primary key, lock=none;
+alter table t1 drop index f1, lock=none;
 ERROR 0A000: LOCK=NONE is not supported. Reason: Dropping a primary key is not allowed without also adding a new primary key. Try LOCK=SHARED
 drop table t1;
 #