reddit/reddit — pull request #929 by grevian (2013-12-12 23:04:44+00:00)
Title: Add _ to list of valid hostname characters

This is in response to https://github.com/reddit/reddit/issues/289

There are more complete URL validation regexes out there, and this is still technically pretty relaxed, all things considered, but it was a 1 character change so I thought I'd give it a try