jamescasbon/PyVCF — pull request #115 by martijnvermaat (2013-08-07 14:51:47+00:00)
Title: Differentiate between no filtering and PASS

Fixes #114

In #114, @AndrewUzilov proposes to track this in a separate field, but I actually think we should do it in a more direct way by explicitely storing `None` if there was no filtering.

Keeping it open for discussion, if there are no objections I'll merge it in a few days.