do not use Item_ref for view fields if it is UPDATE of INSERT (BUG#5263)

mysql-test/r/view.result:
  INSERT into VIEW with ON DUPLICATE
mysql-test/t/view.test:
  INSERT into VIEW with ON DUPLICATE
sql/sql_insert.cc:
  do not use Item_ref for view fields if it is UPDATE of INSERT

mysql-test/r/view.result

@@ -1261,3 +1261,12 @@ create table t1 (a int);
 create view v1 as select a from t1 procedure analyse();
 ERROR HY000: View's SELECT contains a 'PROCEDURE' clause
 drop table t1;
+create table t1 (s1 int, primary key (s1));
+create view v1 as select * from t1;
+insert into v1 values (1) on duplicate key update s1 = 7;
+insert into v1 values (1) on duplicate key update s1 = 7;
+select * from t1;
+s1
+7
+drop view v1;
+drop table t1;

mysql-test/t/view.test

@@ -1219,3 +1219,14 @@ create table t1 (a int);
 -- error 1349
 create view v1 as select a from t1 procedure analyse();
 drop table t1;
+
+#
+# INSERT into VIEW with ON DUPLICATE
+#
+create table t1 (s1 int, primary key (s1));
+create view v1 as select * from t1;
+insert into v1 values (1) on duplicate key update s1 = 7;
+insert into v1 values (1) on duplicate key update s1 = 7;
+select * from t1;
+drop view v1;
+drop table t1;

sql/sql_insert.cc

@@ -582,6 +582,7 @@ int mysql_prepare_insert(THD *thd, TABLE_LIST *table_list, TABLE *table,
   bool insert_into_view= (table_list->view != 0);
   /* TODO: use this condition for 'WITH CHECK OPTION' */
   Item *unused_conds= 0;
+  int res;
   DBUG_ENTER("mysql_prepare_insert");
 
   if (mysql_prepare_insert_check_table(thd, table_list, fields, &unused_conds))
@@ -591,7 +592,10 @@ int mysql_prepare_insert(THD *thd, TABLE_LIST *table_list, TABLE *table,
                           !insert_into_view) ||
       setup_fields(thd, 0, table_list, *values, 0, 0, 0) ||
       (duplic == DUP_UPDATE &&
-       (setup_fields(thd, 0, table_list, update_fields, 0, 0, 0) ||
+       ((thd->lex->select_lex.no_wrap_view_item= 1,
+         (res= setup_fields(thd, 0, table_list, update_fields, 0, 0, 0)),
+         thd->lex->select_lex.no_wrap_view_item= 0,
+         res) ||
         setup_fields(thd, 0, table_list, update_values, 0, 0, 0))))
     DBUG_RETURN(-1);