Confirmed on 5.6.15-56-log Percona XtraDB Cluster

mysql> show global variables like '%version%';
+-------------------------+----------------------------------------------------------------------------+
| Variable_name           | Value                                                                      |
+-------------------------+----------------------------------------------------------------------------+
| innodb_version          | 5.6.15-rel63.0                                                             |
| protocol_version        | 10                                                                         |
| slave_type_conversions  |                                                                            |
| version                 | 5.6.15-56-log                                                              |
| version_comment         | Percona XtraDB Cluster (GPL), Release 25.5, Revision 759, wsrep_25.5.r4061 |
| version_compile_machine | x86_64                                                                     |
| version_compile_os      | Linux                                                                      |
+-------------------------+----------------------------------------------------------------------------+

mysql> use test
Database changed

mysql> CREATE TABLE update_test (a INT AUTO_INCREMENT PRIMARY KEY, b INT, c INT, INDEX (b,c));
Query OK, 0 rows affected (0.16 sec)

mysql> INSERT INTO update_test (b, c) VALUES (1, 1), (1, 2), (1,3), (2, 2), (2,3), (2,4), (2, 5), (5, 5), (6,6), (7,7);
Query OK, 10 rows affected (0.01 sec)
Records: 10  Duplicates: 0  Warnings: 0

mysql> SELECT * FROM update_test WHERE b = 1 ORDER BY c LIMIT 2;
+---+------+------+
| a | b    | c    |
+---+------+------+
| 2 |    1 |    1 |
| 4 |    1 |    2 |
+---+------+------+
2 rows in set (0.03 sec)

mysql> SHOW SESSION STATUS LIKE 'Sort%';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| Sort_merge_passes | 0     |
| Sort_range        | 0     |
| Sort_rows         | 0     |
| Sort_scan         | 0     |
+-------------------+-------+
4 rows in set (0.00 sec)

mysql> explain SELECT * FROM update_test WHERE b = 1 ORDER BY c LIMIT 2;
+----+-------------+-------------+------+---------------+------+---------+-------+------+--------------------------+
| id | select_type | table       | type | possible_keys | key  | key_len | ref   | rows | Extra                    |
+----+-------------+-------------+------+---------------+------+---------+-------+------+--------------------------+
|  1 | SIMPLE      | update_test | ref  | b             | b    | 5       | const |    3 | Using where; Using index |
+----+-------------+-------------+------+---------------+------+---------+-------+------+--------------------------+
1 row in set (0.00 sec)

mysql> UPDATE update_test SET a = a + 13 WHERE b = 1 ORDER BY c LIMIT 2;
Query OK, 2 rows affected (0.69 sec)
Rows matched: 2  Changed: 2  Warnings: 0

mysql> SHOW SESSION STATUS LIKE 'Sort%';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| Sort_merge_passes | 0     |
| Sort_range        | 1     |
| Sort_rows         | 2     |
| Sort_scan         | 0     |
+-------------------+-------+
4 rows in set (0.00 sec)

mysql> EXPLAIN UPDATE update_test SET a = a + 13 WHERE b = 1 ORDER BY c LIMIT 2;
+----+-------------+-------------+-------+---------------+------+---------+-------+------+-----------------------------+
| id | select_type | table       | type  | possible_keys | key  | key_len | ref   | rows | Extra                       |
+----+-------------+-------------+-------+---------------+------+---------+-------+------+-----------------------------+
|  1 | SIMPLE      | update_test | range | b             | b    | 5       | const |    3 | Using where; Using filesort |
+----+-------------+-------------+-------+---------------+------+---------+-------+------+-----------------------------+
1 row in set (0.00 sec)