which picks up all loose objects that are still live and creates
a new pack.
This implements --unpacked=<existing pack> option to tell the
revision walking machinery to pretend as if objects in such a
pack are unpacked for the purpose of object listing. With this,
we could say:
instead, to mean "all live loose objects but pretend as if
objects that are in this pack are also unpacked". The newly
created pack would be perfect for updating $active_pack by
replacing it.
Since pack-objects now knows how to do the rev-list's work
itself internally, you can also write the above example by: