MDEV-7482 VIEW containing INTERVAL(...)

Item_func::print() prints itself as name + "(" + arguments + ")".
Normally that works, but Item_func_interval internally implements its
arguments as one single Item_row. Item_row prints itself as
"(" + values + ")". As a result, "INTERVAL(1,2)" was being printed
as "INTERVAL((1,2))". Fixed with a custom Item_func_interval::print().

mysql-test/r/func_set.result

@@ -5,7 +5,7 @@ explain extended select INTERVAL(55,10,20,30,40,50,60,70,80,90,100),interval(3,1
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
-Note	1003	select interval((55,10,20,30,40,50,60,70,80,90,100)) AS `INTERVAL(55,10,20,30,40,50,60,70,80,90,100)`,interval((3,1,(1 + 1),(((1 + 1) + 1) + 1))) AS `interval(3,1,1+1,1+1+1+1)`,field('IBM','NCA','ICL','SUN','IBM','DIGITAL') AS `field("IBM","NCA","ICL","SUN","IBM","DIGITAL")`,field('A','B','C') AS `field("A","B","C")`,elt(2,'ONE','TWO','THREE') AS `elt(2,"ONE","TWO","THREE")`,interval((0,1,2,3,4)) AS `interval(0,1,2,3,4)`,(elt(1,1,2,3) | 0) AS `elt(1,1,2,3)|0`,(elt(1,1.1,1.2,1.3) + 0) AS `elt(1,1.1,1.2,1.3)+0`
+Note	1003	select interval(55,10,20,30,40,50,60,70,80,90,100) AS `INTERVAL(55,10,20,30,40,50,60,70,80,90,100)`,interval(3,1,(1 + 1),(((1 + 1) + 1) + 1)) AS `interval(3,1,1+1,1+1+1+1)`,field('IBM','NCA','ICL','SUN','IBM','DIGITAL') AS `field("IBM","NCA","ICL","SUN","IBM","DIGITAL")`,field('A','B','C') AS `field("A","B","C")`,elt(2,'ONE','TWO','THREE') AS `elt(2,"ONE","TWO","THREE")`,interval(0,1,2,3,4) AS `interval(0,1,2,3,4)`,(elt(1,1,2,3) | 0) AS `elt(1,1,2,3)|0`,(elt(1,1.1,1.2,1.3) + 0) AS `elt(1,1.1,1.2,1.3)+0`
 SELECT INTERVAL(13, 7, 14, 21, 28, 35, 42, 49, 56);
 INTERVAL(13, 7, 14, 21, 28, 35, 42, 49, 56)
 1

mysql-test/r/view_alias.result

@@ -109,3 +109,11 @@ DROP VIEW v1;
 CREATE VIEW v1 AS select `test`.`t1`.`a` AS `a` from `test`.`t1` where exists(select '  a   ' AS `alias` from `test`.`t1` group by '  a   ');
 DROP VIEW v1;
 DROP TABLE t1, t2;
+create view v1 as select interval(55,10) as my_col;
+show create view v1;
+View	Create View	character_set_client	collation_connection
+v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS select interval(55,10) AS `my_col`	latin1	latin1_swedish_ci
+select * from v1;
+my_col
+1
+drop view v1;

mysql-test/t/view_alias.test

@@ -90,3 +90,12 @@ eval CREATE VIEW v1 AS $query;
 DROP VIEW v1;
 
 DROP TABLE t1, t2;
+
+#
+# MDEV-7482 VIEW containing INTERVAL(...)
+#
+create view v1 as select interval(55,10) as my_col;
+show create view v1;
+select * from v1;
+drop view v1;
+

sql/item_cmpfunc.h

@@ -734,6 +734,11 @@ class Item_func_interval :public Item_int_func
   void fix_length_and_dec();
   const char *func_name() const { return "interval"; }
   uint decimal_precision() const { return 2; }
+  void print(String *str, enum_query_type query_type)
+  {
+    str->append(func_name());
+    print_args(str, 0, query_type);
+  }
 };