Re: [PATCH 4/5] revision.c: refactor ref selection handler after --exclude

On Thu, Jan 26, 2017 at 04:28:17PM +0700, Duy Nguyen wrote:

On Thu, Jan 26, 2017 at 3:57 AM, Jeff King [off-list ref] wrote:

quoted

I don't think it means either. It means to include remotes in the
selected revisions, but excluding the entries mentioned by --exclude.

IOW:

  --exclude=foo --remotes
        include all remotes except refs/remotes/foo

  --exclude=foo --unrelated --remotes
        same

  --exclude=foo --decorate-reflog --remotes
        decorate reflogs of all remotes except "foo". Do _not_ use them
        as traversal tips.

  --decorate-reflog --exclude=foo --remotes
        same

IOW, the ref-selector options build up until a group option is given,
which acts on the built-up options (over that group) and then resets the
built-up options. Doing "--unrelated" as above is orthogonal (though I
think in practice nobody would do that, because it's hard to read).

This is because it makes sense to combine --exclude and
--decorate-reflog. But what about a new --something that conflicts
with either --exclude or --decorate-reflog? Should we simply catch
such combinations and error out (which may be a bit more complicated
than this patch, or maybe not)?

I'd cross that bridge when we see what the option is. But my gut is that
rules would be:

  - apply all non-conflicting relevant options. So:

      --exclude=foo/* --decorate-refs --decorate-reflog --remotes

    would presumably decorate both ref tips _and_ reflogs for all
    remotes (except ones in refs/remotes/foo/*)

  - for ones that are directly related and override each other,
    use the usual last-one-wins rule. So:

      --decorate-reflog --no-decorate-reflog --remotes

    would countermand the original --decorate-reflog.

  - for ones that really have complex interactions, notice and complain
    in handle_refs().

That just seems to me like it follows our usual option parsing
procedure. The only difference here is that process and reset some
subset of the flags when we hit a special marker option ("--remotes" in
these examples) instead of doing it at the end.

-Peff