Re: [PATCH v2] filter-branch: return 2 when nothing to rewrite

[Jeff King <peff@peff.net>]

On Thu, Mar 15, 2018 at 06:09:18PM +0100, Michele Locati wrote:

> Using the --state-branch option allows us to perform incremental filtering.
> This may lead to having nothing to rewrite in subsequent filtering, so we need
> a way to recognize this case.
> So, let's exit with 2 instead of 1 when this "error" occurs.

Thanks, this looks good to me.

I did have one other thought while reading this, but I think it's OK to
leave as-is:

> +EXIT STATUS
> +-----------
> +
> +On success, the exit status is `0`.  If the filter can't find any commits to
> +rewrite, the exit status is `2`.  On any other error, the exit status may be
> +any other non-zero value.

I wondered if people might take "any commits to rewrite" to also mean
the case where the filters do not actually change any commits (e.g, and
index filter which removes a path that does not exist). That's currently
a successful outcome but does issue a warning; it's not changed by this
patch at all (and nor should it be).

If we wanted to make that more clear, we could perhaps mention the
--state-branch option here explicitly. Not sure if it's worth it.

-Peff