Merge branch '10.1' into 10.2

Revert commit db0917f68f, because the fix for MDEV-12696
is coming from 5.5 and 10.1 in this merge.

1 files changed, 7 insertions, 0 deletions

diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index 83bd9ed0bdf..72ea63612f0 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -724,6 +724,13 @@ public:
     in_strategy= (SUBS_STRATEGY_CHOSEN | strategy);
     DBUG_VOID_RETURN;
   }
+
+  bool walk(Item_processor processor, bool walk_subquery, void *arg)
+  {
+    return left_expr->walk(processor, walk_subquery, arg) ||
+           Item_subselect::walk(processor, walk_subquery, arg);
+  }
+
   bool exists2in_processor(void *opt_arg __attribute__((unused)))
   {
     return 0;