trema/trema — pull request #304 by infrastation (2013-06-04 16:23:09+00:00)
Title: fix segfault on portless OFPT_FEATURES_REPLY

Only the bugfix is here, the unit tests were left intact. There is an existing test named ```test_handle_features_reply_without_phy_port```, but I was not sure how and if it should be updated.