Re: [PATCH] builtin-commit: fix "git add x y && git commit y" committing x, too

Junio C Hamano [off-list ref] writes:

I noticed that the implementation left next-index crufts almost
every time it was run, and started to clean it up.  Here is
still a WIP and it does not optimize the read_tree(HEAD) part,
but you should be able to replace that part with your one-way
merge easily.  As I haven't done that ls-files --error-unmatch
equivalent, this does not pass tests that involve partial
commits with added or removed paths.

I was working on this tonight.  Will send out a proposed fix
based on this WIP shortly.  The result seems to pass all the
tests.