Re: [PATCH] update-index: add --swap to swap index and worktree content

[Jeff King <peff@peff.net>]

On Wed, Aug 17, 2011 at 10:13:08AM -0400, Martin von Zweigbergk wrote:

> >> Two reasons. I already mentioned the ability to quickly checkout index
> >> for a quick test (though there could be more problems down that road).
> >
> > That's a good thought. However, in practice, I find I also need other
> > files from the index to do a successful test. So I end up just
> > committing what I think is right, and then afterwards do:
> 
> Maybe a stupid question, but "update-index --swap" would swap all
> files, right? So what "other files from the index" would there be?

Hmm. I hadn't really considered swapping everything. I suppose that
would work, though I do worry about getting into a confused state when
you have swapped one or more files individually, and then want to swap
the rest out for testing.

That is, there is no flag to say "this file was swapped", so there is no
way to say "swap all of the index files out, except those I have already
swapped". But if you were disciplined to only do:

  git update-index --swap
  $EDITOR foo.c
  make test
  git update-index --swap

and never:

  git update-index --swap foo.c
  $EDITOR foo.c
  git update-index --swap ;# oops, we put the WT foo.c back
  make test
  git update-index --swap

then it would work.

-Peff