From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 04 Feb 2021 18:56:06 GMT
Subject: Re: [PATCH v4 1/3] range-diff/format-patch: refactor check for commit range
Message-ID: <xmqqy2g364s9.fsf@gitster.c.googlers.com>
In-Reply-To: <b98fa94b87037b811ea973c1aeb7cfe08d7c1bd6.1612431093.git.gitgitgadget@gmail.com>

"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.