Re: diff machinery cleanup

On Thu, Aug 10, 2006 at 02:36:49AM -0700, Junio C Hamano wrote:

In general, run_diff_X are _not_ designed to run twice.

OK, makes sense. As you probably guessed, the reason is for the
run-status in C.

If you are working in "next" branch where Johannes's merge-recur
work introduced discard_cache(), you could fake this somehow
stashing away a copy of the original index, and once you are
done with run_diff_index(), clean the slate by calling
discard_cache() once you are done, and swap the original index
in before running run_diff_files().

OK, doing a discard_cache() between the call to run_diff_index and
run_diff_files seems to clear up the problem. But if I understand
correctly, are you saying that run_diff_index has munged the index on
disk, and I really need to be poking at a temporary copy? If so, why
isn't that a problem when running (e.g.) "git-diff-index; git-ls-files"?

To solve this cleanly without doing the index munging hack, you
would (actually, I would) need to have a new path walker that
walks index, tree and working tree in parallel, which I was
working on in the git-status/git-commit rewrite I started and
discarded a few days ago.

That does sound the cleanest, and it would enable a more useful status
message, as you mentioned before. What caused you to stop working on it?
Infeasible, or simply more infeasible than you would like right now?

-Peff