Re: [PATCH v3 1/6] stash: mark `i_tree' in reset_tree() const

From: Junio C Hamano <gitster@pobox.com>
To: Alban Gruin <alban.gruin@gmail.com>
Cc: git@vger.kernel.org,
	Christian Couder <christian.couder@gmail.com>,
	Thomas Gummerer <t.gummerer@gmail.com>,
	Son Luong Ngoc <sluongng@gmail.com>
Subject: Re: [PATCH v3 1/6] stash: mark `i_tree' in reset_tree() const
Date: Fri, 31 Jul 2020 11:28:24 -0700	[thread overview]
Message-ID: <xmqqtuxn35fb.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <20200731165140.29197-2-alban.gruin@gmail.com> (Alban Gruin's message of "Fri, 31 Jul 2020 18:51:35 +0200")

Alban Gruin <alban.gruin@gmail.com> writes:

> In reset_tree(), the value pointed by `i_tree' is not modified.  In a

This helper function is about "reset the working tree and the index
to match this given tree object" and it is clear that it is an
input-only parameter, so that alone is a good justification for code
hygiene.  Good.

> latter commit, it will be provided with `the_hash_algo->empty_tree',
> which is a constant.  Hence, this changes `i_tree' to be a constant.
>
> Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
> ---
>  builtin/stash.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/builtin/stash.c b/builtin/stash.c
> index 0c52a3b849..9baa8b379e 100644
> --- a/builtin/stash.c
> +++ b/builtin/stash.c
> @@ -228,7 +228,7 @@ static int clear_stash(int argc, const char **argv, const char *prefix)
>  	return do_clear_stash();
>  }
>  
> -static int reset_tree(struct object_id *i_tree, int update, int reset)
> +static int reset_tree(const struct object_id *i_tree, int update, int reset)
>  {
>  	int nr_trees = 1;
>  	struct unpack_trees_options opts;