What I do for a full merge it to check out a clean
copy of the HEAD (with -kk) and then do
cvs update -joacs-4-6 -kk
in the top directory, then do a
cvs -n update > log
to get modified or conflicting files, resolve the conflicts
in bulk with
emacs `egrep ^C log | awk '{print $2}'`
then look over a cvs diff to try to make sure the changes make sense, then commit the lot. Oh, and probably tag the
HEAD as something like jcd-premerge. It makes sense to tag the 4.6 branch as well before the update -j, although last time I neglected to do so.
If its just a few files or a package I would not jump through
so many hoops and probably just do it with an existing checkout, taking care not to pull in any other changes
accidentally.