Bug#438486: [debfile] Don't throw an exception on extra .deb members

[Romain Francoise]

Package: python-debian
Version: 0.1.4

The DebFile class constructor checks that the given .deb file
contains the following archive members:

 DATA_PART = 'data.tar.gz'
 CTRL_PART = 'control.tar.gz'
 INFO_PART = 'debian-binary'

and throws an exception if there are extra members.  This causes
failures on 36 packages currently in the archive (on my amd64
mirror):

 - 34 packages contain an extra member named '_gpgbuilder', which is
   a file generated by dpkg-sig.

 - 2 packages use bz2 compression for the data tarball, hence they
   have data.tar.bz2 but not data.tar.gz.  I think that this is a
   policy violation, but that's beyond the scope of this bug report.

deb(5) says the following about extra members:

| Current implementations should ignore any additional
| members after data.tar.gz.

So if DebFile could just ignore those extra members instead of
throwing an exception, that'd be nice.

Thanks,

-- 
  ,''`.
 : :' :        Romain Francoise <rfrancoise at debian.org>
 `. `'         http://people.debian.org/~rfrancoise/
   `-