Proposed change to dpkg behaviour

[Ian Jackson <ian@chiark.chu.cam.ac.uk>]

I propose to add yet another control file field:
  Replaces: <dependency-specification>
(syntax the same as Conflicts, including the optional version spec).

The effects will be:

* Suppose you have A installed, and want to install B, which conflicts
with A.  If B declares `Replaces: A' then you don't need to deselect A
first (by using dpkg --remove and having it fail, or using dselect).
This may make dselect's job easier too - it will always deselect A in
favour of B, and perhaps copy A's `wanted' state to B.

* Suppose that you have A installed, and install B, which *doesn't*
conflict with A.  B is allowed to overwrite A's files.  This implies a
GENERAL GHANGE IN DPKG BEHAVIOUR - namely, that it will usually REFUSE
TO OVERWRITE FILES FROM ANOTHER PACKAGE.

Comments ?

Ian.