From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 17 Sep 2013 22:14:39 GMT
Subject: Re: [BUG?] git checkout $commit -- somedir doesn't drop files
Message-ID: <xmqqd2o7w0xc.fsf@gitster.dls.corp.google.com>
In-Reply-To: <20130917220345.GA22914@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> On Tue, Sep 17, 2013 at 03:00:41PM -0700, Junio C Hamano wrote:
>
>> > 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?
>
> Yes, that is what I meant.

Yeah, then I agree that "git checkout HEAD^ -- subdir" should be a
one-way "go HEAD^" merge limited only to the paths that match
subdir/.

If implemented in a straight-forward way, I suspect that we may end
up not removing subdir/b in Uwe's sample transcript. I am not sure
if that is a good thing or not, though.  If the index originally
tracked and then "going to" tree does not, I think removing it would
match "ignore local modifications" rule, as subdir/a that is tracked
in the index and also in "going to" tree does get overwritten to
match the state recorded in the tree.