Apply upstream changes:

3ca1d7b07cf7b7c7433e8dabbcbc566c64c6e07f Don't make exceeding magic
offsets an error; just fail this magic entry test. Consider truncated
files...

20c59ad54afc7427ea680f84c8ee5a576ba54b08: Downgrade DER comparison
and offset lookup failures to be handled as match failures.

Upstream bug: http://bugs.gw.com/view.php?id=540