Re: [RFC PATCH] rev-list: clarify --abbrev and --abbrev-commit usage

Emily Shaffer [off-list ref] writes:

It looks like `git log --abbrev=5` also doesn't work the way one might
expect, which makes sense to me, as they use the same internals for
option parsing (parse_revisions()).

I suspect that was primarily because --abbrev-commit was only to
abbreviate the commit object names on the log header, and --abbrev
was to abbreviate the object names seen in the --raw output.  These
days, even --raw output seems to abbreviate by default, so --abbrev
alone lost its usefulness quite a bit.