spider outputs wrong results when SELECTing columns not in GROUP BY

modified   storage/spider/mysql-test/spider/bugfix/t/mdev_34659.test

@@ -5,6 +5,7 @@

 --enable_query_log

 SET spider_same_server_link= on;

+SET spider_disable_group_by_handler= 1;

 SET sql_mode='';

 evalp CREATE SERVER srv FOREIGN DATA WRAPPER mysql

 OPTIONS (SOCKET "$MASTER_1_MYSOCK", DATABASE 'test',user 'root');

@@ -18,6 +19,7 @@ SELECT * FROM t2 ORDER BY CAST(c AS INET6);

 --enable_view_protocol

 SELECT * FROM t2 GROUP BY CAST(c AS char(60));

 SELECT * FROM t2 GROUP BY CAST(c AS INET6);

+SELECT * FROM t1 GROUP BY CAST(c AS INET6);

 # Cleanup

 DROP TABLE t1,t2;

 drop server srv;

 SELECT * FROM t2 GROUP BY CAST(c AS INET6);

 c

+123

+Warnings:

+Warning	1292	Incorrect inet6 value: '123'

+SELECT * FROM t1 GROUP BY CAST(c AS INET6);

+c

 456

+Warnings:

+Warning	1292	Incorrect inet6 value: '456'

+Warning	1292	Incorrect inet6 value: '123'

commit 9ba56c072c016cf226a796ca64f227f253be70c9

Author: Kentoku Shiba <kentokushiba@gmail.com>

Date:   Mon Apr 27 08:46:30 2020 +0900

    Add a parameter spider_strict_group_by for supporting ONLY_FULL_GROUP_BY

select min(`c`) from `test`.`t1` group by cast(`c`as inet6)

CREATE TABLE t2 (c INT) ENGINE=Spider COMMENT='WRAPPER "mysql",SRV "srv",TABLE "t1", strict_group_by "0"';