Re: [BUG?] git checkout $commit -- somedir doesn't drop files

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

Jeff King <peff@peff.net> writes:

> On Tue, Sep 17, 2013 at 01:40:17PM -0700, Junio C Hamano wrote:
>
>> Taking the state of a subdirectory as a whole as "content", the
>> change we are discussing will make it more like "rm -fr dir && tar
>> xf some-content dir" to replace the directory wholesale, which I
>> personally think is a good thing in the longer term.
>
> Yeah, that makes sense. What about untracked files?

Obviously we cannot literally do "rm -fr dir && tar x", but I agree
that if tree-ish has a path that is not tracked in the current
index, the path should be overwritten and made identical to what is
in the tree-ish.

> Right now we overwrite them if the tree-ish has an entry at the same
> path; that is a bit more dangerous than the rest of git, but does match
> the "ignore local modifications" rule. I assume if we handled deletions,
> though, that we would simply leave them be.
>
> So given that, is it fair to say that a one-way "go here" merge, limited
> by pathspec, is the closest equivalent?

Sorry, but it is unclear to me what you mean by one-way "go here"
merge.  Do you mean oneway_merge() in unpack-trees.c?