Re: wishlist: "--cached|--staged" to "git commit file(s)"

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 13, 2018, 21:33 UTC
Message-ID: <xmqqva8e2bpf.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20180813162236.GO732@hopa.kiewit.dartmouth.edu>

Yaroslav Halchenko <yoh@onerussian.com> writes:

> command.  ATM there is no non-interactive (via --patch/--interactive I
> think it is possible) way to commit selected subset of staged files not
> from the worktree (as it is done with "git commit file(s)") but from the
> index.

Hmph, so

	edit A B C
	git add A B
	edit A B C
	git commit --cached B

would create a commit that is different from the original HEAD by the edit to file B you did in the first step, but not the edit to A or C, or edit to B after you did "git add"?

That sounds like a useful feature. If you do not need that "exclude the later edit since the last 'git add'", you can do "git commit B", but if you added crufts to B in the working tree since you added a good copy of B to the index, that would not do what you want to do.

Sounds like a good starter project for somebody who wants to try to get their hands dirty. I think it is just the matter of updating builtin/commit.c::prepare_index() where COMMIT_PARTIAL is handled, skipping "(2) update the index with the given paths" when "--cached" option is given, but doing everything else in that codepath.