hardcoded -C argument to ${INSTALL}

[Garrett Wollman]

<<On Tue, 6 May 2003 20:09:49 -0400, Garance A Drosihn <drosih at rpi.edu> said:

> I think this "remove stale pieces" issue is one that we have
> to find a decent solution to, because it keeps popping up
> every few months (in slightly different contexts), and it's
> going to drive us all nuts.

...which is odd because releases have come with mtree files for quite
a few years now, and they contain all the information necessary to
compute the set difference between two arbitrary releases.  It
wouldn't take too much programming to add a flag to mtree(8) which
implements the `read the spec file and output a list of files which
ought to be present' function, and then all you need is sort(1) and
comm(1) to determine which files went away for any pair of releases
since the mtree files started being distributed (which includes all
the ones that matter).  Of course, you could just use `mtree' to
delete the old files for you, but you have to be very careful when
doing that not to delete the user's files, too.

-GAWollman