From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junio C Hamano <gitster@pobox.com>
Subject: Re: [RFC/PATCH v3] merge-base: teach "git merge-base" to accept more
 than 2 arguments
Date: Sun, 27 Jul 2008 22:37:24 -0700
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References: <20080728065023.743930d6.chriscool@tuxfamily.org>
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Cc: git@vger.kernel.org,
	Johannes Schindelin <Johannes.Schindelin@gmx.de>,
	Miklos Vajna <vmiklos@frugalware.org>,
	Jakub Narebski <jnareb@gmail.com>
To: Christian Couder <chriscool@tuxfamily.org>
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In-Reply-To: <20080728065023.743930d6.chriscool@tuxfamily.org> (Christian
 Couder's message of "Mon, 28 Jul 2008 06:50:23 +0200")
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Christian Couder <chriscool@tuxfamily.org> writes:

> Before this patch "git merge-base" accepted only 2 arguments, so
> only merge bases between 2 references could be computed.
>
> The purpose of this patch is to make "git merge-base" accept more
> than 2 arguments, so that the merge bases between the first given
> reference and all the other references can be computed.

I have trouble with this wording, but I'll comment on the documentation
part in a separate message.

> +static struct commit *get_commit_reference(const char *arg)
> +{
> +	unsigned char revkey[20];
> +	if (get_sha1(arg, revkey))
> +		die("Not a valid object name %s", arg);
> +	return lookup_commit_reference(revkey);
> +}

This returns a NULL when you feed a tree to the command, and...

>  int cmd_merge_base(int argc, const char **argv, const char *prefix)
>  {
> +	struct commit **rev;
>  	int show_all = 0;
> +	int rev_nr = 0;
>  
>  	git_config(git_default_config, NULL);
>  
> @@ -38,15 +48,18 @@ int cmd_merge_base(int argc, const char **argv, const char *prefix)
>  			usage(merge_base_usage);
>  		argc--; argv++;
>  	}
> +	if (argc < 3)
>  		usage(merge_base_usage);
> +
> +	rev = xmalloc((argc - 1) * sizeof(*rev));
> +
> +	do {
> +		struct commit *r = get_commit_reference(argv[1]);
> +		if (!r)
> +			return 1;

... the command silently exits with 1.