bundle2._processpart: forcing lower-case compare is no longer necessary Encoding whether or not a part is mandatory in the capitalization of the parttype is unintuitive and error-prone. This sequence of patches separates these concerns in the API to reduce programmer error and pave the way for a potential change in how this information is transmitted over the wire. Since the parttype and mandatory bit are separated in bundle2.unbundlepart (see previous patch), there is no longer a need to remove the mandatory bit before working with the parttype.