Re: [PATCH 4/6] checkout-index: handle "--no-index" option

[Jeff King <peff@peff.net>]

On Sun, Jan 31, 2016 at 06:25:22PM -0800, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > I also reformatted the comment that violated our style
> > guidelines, but I am not sure if it is all that helpful. It
> > seems we also cancel "--index" with "--temp" or
> > "--stage=all", but I do not know why. I left the content
> > as-is, but if somebody knows enough to elaborate, it might
> > be worth doing.
> 
> Isn't the --index about updating the cached stat information, to
> allow us to then say "the working tree file hasn't been modified
> since we wrote it out"?  After writing a file out to somewhere that
> is not its natural location (i.e. using prefix, stage or temp would
> all write the contents of F to somewhere that is not F), the next
> "diff-files" would not compare the index entry with the contents
> held in that relocated location, but with its natural location.

Yeah, that makes sense to me. I should have said "...but I do not know
why, and I did not really look into it" in my original.

That probably makes it OK to silently ignore (as opposed to complaining
that "--prefix" is used with "--index"). It is not so much "these
options are incompatible" as the fact that there is no entry to update
in the case of a prefix or tempfile. So "--index" is still in effect, it
just has no work to do. :)

-Peff