Bug#823625: Interpret "apt-get install foo bar-" to prevent install of any arch-variants of "bar"

["Daniel Richard G." <skunk@iSKUNK.ORG>]

Package: apt
Version: 1.2.11
Severity: wishlist

This RFE was split off from bug #673193 by the maintainer's request.

When one specifies a command like

    # apt-get install foo bar-

the intent is usually to install package "foo" while preventing package
"bar" from being pulled in as a dependency (assuming that "bar" is not
already installed, and is not a hard dependency of "foo").

With multi-arch support, however, this can currently lead to the
unexpected behavior where "bar"---equivalent to e.g. "bar:amd64" on an
amd64 system---is correctly declined for installation, but "bar:i386"
gets pulled in instead.

The original intent of the command is likely to have been "don't pull in
package 'bar' at all." This can be better expressed by specifying
"bar:*-", though this may have the undesired effect of additionally
removing pre-installed variants of "bar".

This request, then, is for "bar-" to prevent installation not just of
the native-arch variant of "bar", but all arch variants, to better align
with the usual intent behind that syntax.