MDEV-16957: Server crashes in Field_iterator_natural_join::next upon 2nd execution of SP

The problem was that join_columns creation was not finished due to error of notfound column in USING, but next execution tried to use join_columns lists.

Solution is cleanup the lists on error. It can eat memory in statement MEM_ROOT but it is an error and error will be fixed or statement/procedure removed/altered.

1 files changed, 10 insertions, 0 deletions

diff --git a/sql/table.h b/sql/table.h
index 1d4a1d9a2d2..4725eb96432 100644
--- a/sql/table.h
+++ b/sql/table.h
@@ -2184,6 +2184,16 @@ struct TABLE_LIST
   } 
   void set_lock_type(THD* thd, enum thr_lock_type lock);
 
+  void remove_join_columns()
+  {
+    if (join_columns)
+    {
+      join_columns->empty();
+      join_columns= NULL;
+      is_join_columns_complete= FALSE;
+    }
+  }
+
 private:
   bool prep_check_option(THD *thd, uint8 check_opt_type);
   bool prep_where(THD *thd, Item **conds, bool no_where_clause);