Bug #48291 : crash with row() operator,select into @var, and

  subquery returning multiple rows

Error handling was missing when handling subqueires in WHERE 
and when assigning a SELECT result to a @variable.
This caused crash(es). 

Fixed by adding error handling code to both the WHERE 
condition evaluation and to assignment to an @variable.

1 files changed, 4 insertions, 2 deletions

diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 7d26759cb16..06f2229a050 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -2068,9 +2068,11 @@ bool select_dumpvar::send_data(List<Item> &items)
     else
     {
       Item_func_set_user_var *suv= new Item_func_set_user_var(mv->s, item);
-      suv->fix_fields(thd, 0);
+      if (suv->fix_fields(thd, 0))
+        DBUG_RETURN (1);
       suv->save_item_result(item);
-      suv->update();
+      if (suv->update())
+        DBUG_RETURN (1);
     }
   }
   DBUG_RETURN(0);