@@ -10482,6 +10478,29 @@ window_func:

         |

           sum_expr

           {

+            ((Item_sum *) $1)->mark_as_window_func_sum_expr();

+          }

+        |

+          function_call_generic

+          {

+            /*

+            We want to allow UDF aggregate (UDAF) functions as Window functions.

+            function_call_generic handles UDAF, so we leverage

+            that and then filter out anything that isn't a UDAF.

+            */

+        Item* item = (Item*)$1;

+            if (item == NULL)

+        {

+              my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION", "");

+              MYSQL_YYABORT;

+        }

+            if ((item->type() != Item::SUM_FUNC_ITEM)

+        || (((Item_sum *)item)->sum_func() != Item_sum::UDF_SUM_FUNC))

+        {

+              my_error(ER_SP_DOES_NOT_EXIST, MYF(0), "FUNCTION", ((Item_func_sp*)item)->func_name());

+              MYSQL_YYABORT;

+        }

+

             ((Item_sum *) $1)->mark_as_window_func_sum_expr();

           }

         ;