Bug#632596: apt-key: could use tempfiles for dummy gpg keyrings

[dirson@debian.org]

Package: apt
Version: 0.8.10.3+squeeze1
Severity: wishlist

gpg seems to require a secring, but since we only ever pass an empty one, there is
no point of keeping an empty secring in /etc/apt/, it seems.  Especially because users
cannot read it, and that seems to prevent apt-keyring from properly operating (or
at least that causes scary messages).

This secring could be created as a tempfile instead on each run.  This would have
the additional benefit of not tempting anyone to add any key into it :)