MDEV-24779: main.subselect fails in buildbot with --ps-protocol

Follow-up fix to commit 26f5033(MDEV-23449)
The GROUP BY clause inside IN/ALL/ANY subquery is removed
when there is no aggregate function or HAVING clause in the subquery.

When the GROUP BY clause is removed, a subquery can also be removed
if it part of the GROUP BY clause. This is done inside the function
remove_redundant_subquery_clauses. Here we walk over the GROUP BY list
and remove a subselect from its unit via the callback function
eliminate_subselect_processor.

The issue here was that when the query was being re-executed it was trying
to reinitialize the select that was removed as stated above.
This is not required, so the fix would be to remove select_lex
both from tree lex structure and the global list of nodes so that
we don't do the reinitialization again.

1 files changed, 1 insertions, 1 deletions

diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index 802bfca64b7..1ef74d19172 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -368,7 +368,7 @@ bool Item_subselect::mark_as_eliminated_processor(void *arg)
 bool Item_subselect::eliminate_subselect_processor(void *arg)
 {
   unit->item= NULL;
-  unit->exclude_from_tree();
+  unit->exclude();
   eliminated= TRUE;
   return FALSE;
 }