MDEV-33742 Do not create group by handler when all tables are constant

sql/sql_select.cc

@@ -3367,7 +3367,7 @@ bool JOIN::make_aggr_tables_info()
     distinct in the engine, so we do this for all queries, not only
     GROUP BY queries.
   */
-  if (tables_list && top_join_tab_count && !procedure)
+  if (tables_list && top_join_tab_count && !only_const_tables() && !procedure)
   {
     /*
       At the moment we only support push down for queries where

storage/spider/mysql-test/spider/bugfix/r/mdev_19866.result

@@ -72,7 +72,6 @@ SELECT argument FROM mysql.general_log WHERE argument LIKE '%select %';
 argument
 select `pkey`,`val` from `auto_test_remote`.`tbl_a`
 select `pkey`,`val` from `auto_test_remote`.`tbl_a` where `pkey` = 1
-select 1 from (select 1) t0
 select `pkey`,`val` from `auto_test_remote`.`tbl_a`
 select `pkey`,`val` from `auto_test_remote`.`tbl_a`
 SELECT argument FROM mysql.general_log WHERE argument LIKE '%select %'
@@ -86,7 +85,6 @@ argument
 select `pkey`,`val` from `auto_test_remote2`.`tbl_a`
 select `pkey`,`val` from `auto_test_remote2`.`tbl_a`
 select `pkey`,`val` from `auto_test_remote2`.`tbl_a` where `pkey` = 2
-select 1 from (select 1) t0
 select `pkey`,`val` from `auto_test_remote2`.`tbl_a`
 SELECT argument FROM mysql.general_log WHERE argument LIKE '%select %'
 SELECT pkey, val FROM tbl_a ORDER BY pkey;

storage/spider/mysql-test/spider/bugfix/r/mdev_33679.result

@@ -18,8 +18,6 @@ INSERT INTO t2_spider VALUES(1,1);
 SELECT t2_spider.a,t1_spider.c FRoM t2_spider LEFT join t1_spider ON (t2_spider.c = t1_spider.c) WHERE t2_spider.a = 1;
 a	c
 1	1
-Warnings:
-Warning	1815	Internal error: Spider group by handler: Encountered multiple equalities, likely an optimizer bug
 drop table t1, t2, t1_spider, t2_spider;
 drop server srv;
 for master_1

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

@@ -86,10 +86,8 @@ SELECT argument FROM mysql.general_log WHERE argument LIKE '%select %';
 argument
 select `value` from `auto_test_remote2`.`tbl_a` where `value` = 5
 select `value2` from `auto_test_remote2`.`tbl_b` where `value2` = 5
-select sum('5') `sum(a.value)`,count('5') `count(b.value2)` from (select 1) t0 join (select 1) t1
 select `value` from `auto_test_remote2`.`tbl_a` where `value` = 5
 select `value2` from `auto_test_remote2`.`tbl_b` where `value2` = 5
-select sum('5') `sum(a.value)`,count('5') `count(b.value2)` from (select 1) t0 join (select 1) t1
 SELECT argument FROM mysql.general_log WHERE argument LIKE '%select %'
 SELECT value FROM tbl_a ORDER BY value;
 value