MDEV-15293 CAST(AS TIME) returns bad results for LAST_VALUE(),NAME_CONST(),SP variable

1 files changed, 24 insertions, 0 deletions

diff --git a/sql/item_windowfunc.h b/sql/item_windowfunc.h
index 9fe95ed6cee..717958d479c 100644
--- a/sql/item_windowfunc.h
+++ b/sql/item_windowfunc.h
@@ -303,6 +303,7 @@ class Item_sum_hybrid_simple : public Item_sum,
   my_decimal *val_decimal(my_decimal *);
   void reset_field();
   String *val_str(String *);
+  bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate);
   const Type_handler *type_handler() const
   { return Type_handler_hybrid_field_type::type_handler(); }
   void update_field();
@@ -938,6 +939,29 @@ public:
     return res;
   }
 
+  bool get_date(MYSQL_TIME *ltime, ulonglong fuzzydate)
+  {
+    bool res;
+    if (force_return_blank)
+    {
+      null_value= true;
+      res= true;
+    }
+    else if (read_value_from_result_field)
+    {
+      if ((null_value= result_field->is_null()))
+        res= true;
+      else
+        res= result_field->get_date(ltime, fuzzydate);
+    }
+    else
+    {
+      res= window_func()->get_date(ltime, fuzzydate);
+      null_value= window_func()->null_value;
+    }
+    return res;
+  }
+
   void split_sum_func(THD *thd, Ref_ptr_array ref_pointer_array,
                               List<Item> &fields, uint flags);