Revert "MDEV-26345 SELECT MIN on Spider table returns more rows than expected"

This reverts commit b9730226.

sql/sql_select.cc

@@ -3278,12 +3278,13 @@ bool JOIN::make_aggr_tables_info()
       /*
         Check if the storage engine can intercept the query.
 
-        The query optimizer might optimize away aggregation functins or DISTINCT.
-        In such a cage, we need to notify a storage engine supporting a group by
-        handler of the existence of the original explicit or implicit grouping.
-        Thus, we set select_distinct || implicit_grouping to Query::distinct.
+        JOIN::optimize_stage2() might convert DISTINCT into GROUP BY and then
+        optimize away GROUP BY (group_list). In such a case, we need to notify
+        a storage engine supporting a group by handler of the existence of the
+        original DISTINCT. Thus, we set select_distinct || group_optimized_away
+        to Query::distinct.
       */
-      Query query= {&all_fields, select_distinct || implicit_grouping, tables_list,
+      Query query= {&all_fields, select_distinct || group_optimized_away, tables_list,
                     conds, group_list, order ? order : group_list, having};
       group_by_handler *gbh= ht->create_group_by(thd, &query);
 

storage/spider/mysql-test/spider/bugfix/r/mdev_26345.result

-for master_1
-for child2
-child2_1
-child2_2
-child2_3
-for child3
-
-MDEV-26345 SELECT MIN on Spider table returns more rows than expected
-
-connection child2_1;
-CREATE DATABASE auto_test_remote;
-USE auto_test_remote;
-CREATE TABLE tbl_a (
-`a`int,
-`b`int,
-PRIMARY KEY (`a`, `b`)
-) ENGINE=InnoDB DEFAULT CHARSET=utf8;
-insert into `tbl_a` VALUES (1,1), (1,2), (2,11);
-connection master_1;
-CREATE DATABASE auto_test_remote;
-USE auto_test_remote;
-CREATE TABLE tbl_a (
-`a`int,
-`b`int,
-PRIMARY KEY (`a`, `b`)
-) ENGINE=Spider DEFAULT CHARSET=utf8 COMMENT='table "tbl_a"' PARTITION BY LIST COLUMNS(`b`) (
-PARTITION `pt1` DEFAULT COMMENT = 'srv "s_2_1"'
-);
-connection master_1;
-SELECT MIN(b), a FROM tbl_a WHERE a=1;
-MIN(b)	a
-1	1
-connection master_1;
-DROP DATABASE IF EXISTS auto_test_remote;
-connection child2_1;
-DROP DATABASE IF EXISTS auto_test_remote;
-for master_1
-for child2
-child2_1
-child2_2
-child2_3
-for child3

storage/spider/mysql-test/spider/bugfix/t/mdev_26345.cnf

-!include include/default_mysqld.cnf
-!include ../my_1_1.cnf
-!include ../my_2_1.cnf

storage/spider/mysql-test/spider/bugfix/t/mdev_26345.test

---disable_warnings
---disable_query_log
---disable_result_log
---source ../../t/test_init.inc
---enable_result_log
---enable_query_log
---enable_warnings
-
---echo
---echo MDEV-26345 SELECT MIN on Spider table returns more rows than expected
---echo
-
---connection child2_1
-CREATE DATABASE auto_test_remote;
-USE auto_test_remote;
-
-eval CREATE TABLE tbl_a (
-    `a`int,
-    `b`int,
-    PRIMARY KEY (`a`, `b`)
-) $CHILD2_1_ENGINE $CHILD2_1_CHARSET;
-
-insert into `tbl_a` VALUES (1,1), (1,2), (2,11);
-
---connection master_1
-CREATE DATABASE auto_test_remote;
-USE auto_test_remote;
-
-eval CREATE TABLE tbl_a (
-    `a`int,
-    `b`int,
-    PRIMARY KEY (`a`, `b`)
-) $MASTER_1_ENGINE $MASTER_1_CHARSET COMMENT='table "tbl_a"' PARTITION BY LIST COLUMNS(`b`) (
-    PARTITION `pt1` DEFAULT COMMENT = 'srv "s_2_1"'
-);
-
---connection master_1
-SELECT MIN(b), a FROM tbl_a WHERE a=1;
-
---connection master_1
-DROP DATABASE IF EXISTS auto_test_remote;
---connection child2_1
-DROP DATABASE IF EXISTS auto_test_remote;
-
---disable_warnings
---disable_query_log
---disable_result_log
---source ../../t/test_deinit.inc
---enable_result_log
---enable_query_log
---enable_warnings

storage/spider/mysql-test/spider/r/direct_join.result

@@ -167,7 +167,7 @@ connection child2_1;
 SELECT argument FROM mysql.general_log WHERE argument LIKE '%select %';
 argument
 select `id`,`hr_status`,`region_code`,`region` from `auto_test_remote`.`tbl_person` where `id` = '24FC3F0A5119432BAE13DD65AABAA39C' and `region` = 510411
-select distinct count(0) `count(0)` from `auto_test_remote`.`tbl_ncd_cm_person` t0 where ((t0.`person_id` = '24FC3F0A5119432BAE13DD65AABAA39C') and (t0.`diseaseKind_id` = '52A0328740914BCE86ED10A4D2521816'))
+select count(0) `count(0)` from `auto_test_remote`.`tbl_ncd_cm_person` t0 where ((t0.`person_id` = '24FC3F0A5119432BAE13DD65AABAA39C') and (t0.`diseaseKind_id` = '52A0328740914BCE86ED10A4D2521816'))
 SELECT argument FROM mysql.general_log WHERE argument LIKE '%select %'
 SELECT * FROM tbl_person;
 id	hr_status	region_code	region