apt: incorrect handling of Filename field with spaces

[Daniel Hartwig]

Separated from bug #1086997.

The original report involves a repository where some path names contain spaces. These end up in the Packages file like:
> Filename: foo/bar baz/file.deb

APT considers the entire line after “Filename: ” to be a single filename value, and issues a HTTP request for the same (note: with a malformed request line, see the other bug).

Packages is a debian control file, subject to debian-policy:
- no filename /value/ may contain a space [Section 5.1]; and
- a Filename field contains multiple values, separated by a space [Appendix D];
so APT has incorrectly read this line as a single filename—“foo/bar baz/file.deb”—when it is actually two: “foo/bar” and “baz/file.deb”.

In this particular case, the repository in question is not technically supported due to the filenames containing spaces (currently prohibited in control files). However, APT should still read this field correctly. Apparently no one is using the multiple-values-in-Filename support, so an alternative is to adjust debian-policy.

Package: apt
Version: 0.9.7.6