yesodweb/Shelly.hs — pull request #79 by InFreefall (2014-10-11 16:20:12+00:00)
Title: Fixed error where certain values of $PATH would raise an exception

It might have just been something weird about my Windows machine's PATH, but absPath was raising an exception because it was passed an empty filepath. Filtering for nonempty filepaths fixes the issue.