MDEV-15424: Unreasonable SQL Error (1356) on select from view

While printing a view containing a window function we were printing it as an
Item_field object instead of an Item_window_func object. This is incorrect and this
leads to us throwing an error ER_VIEW_INVALID.
Fixed by adjusting the Item_ref:print function.
Also made UDF function aware if there arguments have window function.

mysql-test/r/udf.result

@@ -465,3 +465,17 @@ a	b
 Hello	HL
 DROP FUNCTION METAPHON;
 DROP TABLE t1;
+#
+# MDEV-15424: Unreasonal SQL Error (1356) on select from view
+#
+CREATE FUNCTION myfunc_int RETURNS INTEGER SONAME "UDF_EXAMPLE_LIB";
+create table t1(a int , b int);
+insert into t1 values(100, 54), (200, 199);
+create view v1 as select myfunc_int(max(a) over (order by b) , b) from t1;
+select * from v1;
+myfunc_int(max(a) over (order by b) , b)
+154
+399
+drop view v1;
+drop function myfunc_int;
+drop table t1;

mysql-test/r/win.result

@@ -3470,3 +3470,21 @@ SELECT DISTINCT MIN(b1) OVER () FROM t1;
 MIN(b1) OVER ()
 1
 drop table t1;
+#
+# MDEV-15424: Unreasonal SQL Error (1356) on select from view
+#
+create table t1 (id int, n1 int);
+insert into t1 values (1,1), (2,1), (3,2), (4,4);
+create view v1 as SELECT ifnull(max(n1) over (partition by n1),'aaa') FROM t1;
+explain select * from v1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	
+2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	4	Using temporary
+select * from v1;
+ifnull(max(n1) over (partition by n1),'aaa')
+1
+1
+2
+4
+drop table t1;
+drop view v1;

mysql-test/t/udf.test

@@ -528,3 +528,16 @@ DROP FUNCTION METAPHON;
 #INSERT INTO t1 (a) VALUES ('Hello');
 #SELECT * FROM t1;
 DROP TABLE t1;
+
+--echo #
+--echo # MDEV-15424: Unreasonal SQL Error (1356) on select from view
+--echo #
+--replace_result $UDF_EXAMPLE_SO UDF_EXAMPLE_LIB
+eval CREATE FUNCTION myfunc_int RETURNS INTEGER SONAME "$UDF_EXAMPLE_SO";
+create table t1(a int , b int);
+insert into t1 values(100, 54), (200, 199);
+create view v1 as select myfunc_int(max(a) over (order by b) , b) from t1;
+select * from v1;
+drop view v1;
+drop function myfunc_int;
+drop table t1;

mysql-test/t/win.test

@@ -2227,3 +2227,16 @@ EXPLAIN
 SELECT DISTINCT MIN(b1) OVER () FROM t1;
 SELECT DISTINCT MIN(b1) OVER () FROM t1;
 drop table t1;
+
+--echo #
+--echo # MDEV-15424: Unreasonal SQL Error (1356) on select from view
+--echo #
+
+create table t1 (id int, n1 int);
+insert into t1 values (1,1), (2,1), (3,2), (4,4);
+
+create view v1 as SELECT ifnull(max(n1) over (partition by n1),'aaa') FROM t1;
+explain select * from v1;
+select * from v1;
+drop table t1;
+drop view v1;

sql/item.cc

@@ -7815,7 +7815,9 @@ void Item_ref::print(String *str, enum_query_type query_type)
 {
   if (ref)
   {
-    if ((*ref)->type() != Item::CACHE_ITEM && ref_type() != VIEW_REF &&
+    if ((*ref)->type() != Item::CACHE_ITEM &&
+        (*ref)->type() != Item::WINDOW_FUNC_ITEM &&
+        ref_type() != VIEW_REF &&
         !table_name && name && alias_name_used)
     {
       THD *thd= current_thd;

sql/item_func.cc

@@ -3484,6 +3484,8 @@ udf_handler::fix_fields(THD *thd, Item_func_or_sum *func,
       if (item->maybe_null)
 	func->maybe_null=1;
       func->with_sum_func= func->with_sum_func || item->with_sum_func;
+      func->with_window_func= func->with_window_func ||
+                              item->with_window_func;
       func->with_field= func->with_field || item->with_field;
       func->with_param= func->with_param || item->with_param;
       func->with_subselect|= item->with_subselect;