Bug#693092: apt-utils: mishandles -o flags with empty values (-o foo="")

["Aaron M. Ucko" <ucko@debian.org>]

Package: apt-utils
Version: 0.9.7.6
Severity: normal

Running (via live-build)

apt-ftparchive ... -o APT::FTPArchive::Release::Version="" -o APT::FTPArchive::Release::Codename="testing" ... release dists/testing

results in the error

E: Invalid operation APT::FTPArchive::Release::Codename=testing

It looks like apt-ftparchive is ignoring the = symbol and proceeding to
take -o as the Version value and APT::FTPArchive::Release::Codename=testing
as the operation.

This usage is of course dubious, and I will report a bug on live-build for
issuing it; all the same, apt-ftparchive should either accept the empty
Version value or yield a clearer error message.

Could you please take a look?

Thanks!

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (500, 'testing'), (500, 'stable'), (300, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.2.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages apt-utils depends on:
ii  libapt-inst1.5  0.9.7.6
ii  libapt-pkg4.12  0.9.7.6
ii  libc6           2.13-35
ii  libdb5.1        5.1.29-5
ii  libgcc1         1:4.7.1-7
ii  libstdc++6      4.7.1-7

apt-utils recommends no packages.

Versions of packages apt-utils suggests:
ii  xz-utils  5.1.1alpha+20120614-1

-- no debconf information