bugfix: Item_func_dyncol_add::print()

mysql-test/r/dyncol.result

@@ -1878,6 +1878,14 @@ COLUMN_JSON(COLUMN_CREATE('a',1 AS DECIMAL,'b',1 AS DECIMAL))
 #
 # Start of 10.2 tests
 #
+create view v1 as select column_get(column_add(column_create(1 , 'blue' as char), 2, 'ttt'), 1 as char);
+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 column_get(column_add(column_create(1,'blue' AS char charset utf8 ),2,'ttt'),1 as char charset utf8) AS `Name_exp_1`	utf8	utf8_general_ci
+select * from v1;
+Name_exp_1
+blue
+drop view v1;
 #
 # MDEV-10134 Add full support for DEFAULT
 #

mysql-test/t/dyncol.test

@@ -928,6 +928,14 @@ SELECT COLUMN_JSON(COLUMN_CREATE('a',1 AS DECIMAL,'b',1 AS DECIMAL));
 --echo # Start of 10.2 tests
 --echo #
 
+#
+# Item_func_dyncol_add::print
+#
+create view v1 as select column_get(column_add(column_create(1 , 'blue' as char), 2, 'ttt'), 1 as char);
+show create view v1;
+select * from v1;
+drop view v1;
+
 --echo #
 --echo # MDEV-10134 Add full support for DEFAULT
 --echo #

sql/item_strfunc.cc

@@ -4743,7 +4743,7 @@ void Item_func_dyncol_add::print(String *str,
                                  enum_query_type query_type)
 {
   DBUG_ASSERT((arg_count & 0x1) == 1); // odd number of arguments
-  str->append(STRING_WITH_LEN("column_create("));
+  str->append(STRING_WITH_LEN("column_add("));
   args[arg_count - 1]->print(str, query_type);
   str->append(',');
   print_arguments(str, query_type);