puppetlabs/puppet — pull request #1005 by fatpat (2012-08-05 12:45:31+00:00)
Title: Allow environment to match not only purely alphanumeric but alphanumeric plus dash and underscore

Environment must be purely alphanumeric

this pull request changes this to allow dash and underscore with the following regex: /^\w[\w\-_]*$/ (instead of /^\w+$/)