ADD_ONION doesn't validate its target

The target ADD_ONION accepts is documented as matching HiddenServicePort but evidently doesn't validate that it's given a valid address...

>>> GETINFO version
250-version=0.2.7.6-dev (git-b34c5c6b8ac0d13d)
250 OK

>>> ADD_ONION NEW:BEST Port=4567,not_an_address:4567
250-ServiceID=4e5bpsy6e46onv3k
250-PrivateKey=RSA1024:[crypto blob]
250 OK

Honestly I'm a tad mystified since this is breaking Stem's integ tests, but only started manifesting after I reformatted my system yesterday. I'd expect our Jenkins tests to be failing so this might be something local, but if so I'm stumped.