Re: [PATCH 3/5] hook API: support passing stdin to hooks, convert am's 'post-rewrite'

From: Junio C Hamano <gitster@pobox.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: git@vger.kernel.org, Emily Shaffer <emilyshaffer@google.com>,
	Eric Sunshine <sunshine@sunshineco.com>,
	Felipe Contreras <felipe.contreras@gmail.com>,
	Taylor Blau <me@ttaylorr.com>,
	Michael Strawbridge <michael.strawbridge@amd.com>
Subject: Re: [PATCH 3/5] hook API: support passing stdin to hooks, convert am's 'post-rewrite'
Date: Mon, 23 Jan 2023 15:10:22 -0800	[thread overview]
Message-ID: <xmqq3580lue9.fsf@gitster.g> (raw)
In-Reply-To: <patch-3.5-c6b9b69c516-20230123T170551Z-avarab@gmail.com> (=?utf-8?B?IsOGdmFyCUFybmZqw7Zyw7A=?= Bjarmason"'s message of "Mon, 23 Jan 2023 18:15:07 +0100")

Ævar Arnfjörð Bjarmason  <avarab@gmail.com> writes:

> diff --git a/hook.c b/hook.c
> index a4fa1031f28..86c6dc1fe70 100644
> --- a/hook.c
> +++ b/hook.c
> @@ -53,8 +53,14 @@ static int pick_next_hook(struct child_process *cp,
>  	if (!hook_path)
>  		return 0;
>  
> -	cp->no_stdin = 1;
>  	strvec_pushv(&cp->env, hook_cb->options->env.v);
> +	/* reopen the file for stdin; run_command closes it. */
> +	if (hook_cb->options->path_to_stdin) {
> +		cp->no_stdin = 0;
> +		cp->in = xopen(hook_cb->options->path_to_stdin, O_RDONLY);
> +	} else {
> +		cp->no_stdin = 1;
> +	}

Do we need this else clause?  I thought that we've made sure
no_stdin is the default.  Is it just being explicit?

> diff --git a/hook.h b/hook.h
> index 4258b13da0d..19ab9a5806e 100644
> --- a/hook.h
> +++ b/hook.h
> @@ -30,6 +30,11 @@ struct run_hooks_opt
>  	 * was invoked.
>  	 */
>  	int *invoked_hook;
> +
> +	/**
> +	 * Path to file which should be piped to stdin for each hook.
> +	 */
> +	const char *path_to_stdin;
>  };
>  
>  #define RUN_HOOKS_OPT_INIT { \