Re: [PATCH v4 1/3] range-diff/format-patch: refactor check for commit range

> "Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
> writes:
>
> > diff --git a/range-diff.h b/range-diff.h
> > index 583ced2e8e74..c17dbc2e75a8 100644
> > --- a/range-diff.h
> > +++ b/range-diff.h
> > @@ -16,4 +16,12 @@ int show_range_diff(const char *range1, const char *range2,
> >  		    const struct diff_options *diffopt,
> >  		    const struct strvec *other_arg);
> >
> > +/*
> > + * Determine whether the given argument is usable as a range argument of `git
> > + * range-diff`, e.g. A..B. Note that this only validates the format but does
> > + * _not_ parse it, i.e. it does _not_ look up the specified commits in the
> > + * local repository.
> > + */
> > +int is_range_diff_range(const char *arg);
>
> If we were to use [v4 2/3], then we do parse it, even though we do
> use the parse result to reject some valid ranges (like "a history
> all the way down to root" in the implementation).  I think just
> dropping everything after "Note that" is a sufficient fix.