Re: 'git commit --short' without touching index?

Jeff King [off-list ref] writes:

It would be nice if the index-refreshing code only wrote to the index if
there was something worth writing. I'm not sure how hard that would be
to implement, though.

Hmm, don't we already do that with "istate->cache_changed"?

In any case, we should diagnose "commit --short" (and "--procelain") as an
error, perhaps by splitting option parsers for commit and status further.