Re: [PATCH 5/7] diff_tree(): Skip skip_uninteresting() when all remaining paths interesting

[Junio C Hamano <gitster@pobox.com>]

This and the previous patch seem to make sense to me, independent of the
rest.

As to mixing pathspecs with --objects, I would say it is unfair to Linus
to call it a bug that that particular use case has not been supported.  I'd
say it _is_ a bug that we didn't error out when --objects was given with
pathspec at the command line level, though, as that is a combination we
knowingly ignored to support.

It simply hasn't been deemed as a sane operation to produce a pack using
an output from rev-list with pathspec and --objects, as it will leave some
trees and blobs that the pack knows about in the result, without actually
having them in it.  In the context of "narrow clone", these wounds to
trees are deliberate, and the existence of these wounds alone is not the
reason why I called it insane to produce such a pack.

To make use of such a pack, however, you need to somehow cauterize these
deliberate wounds in trees so that fsck, a later run of pack-objects,
fetch-pack and friends will not choke on them.  We didn't plan to have
such an infrastructure so far, and that is what made such a pack with
thousands of cuts "insane".  As soon as "narrow clone" addresses that
issue, mixture of pathspecs with --objects stops being an insane use
case.