Fails to identify some ZIP files

[DavidBuchanan314]

For example, this one:

In fact, the only filetype identified is PNG.

Not detecting the PDF is understandable, since it's out-of-spec - the header appears too far into the file - although Firefox can still render it.

[ESultanik]

As of version v0.3.0, PolyFile uses the libmagic file definition database (also used for the file command). Unfortunately, this database is rather strict, and only classifies this file as a PNG. You can confirm this by running file -k polyglot.png. We are in the process of relaxing these definitions such that more formats would be detected in this file. We expect this to be included in the next release (v0.3.5).