Re: [RFC/PATCH v3] merge-base: teach "git merge-base" to accept more than 2 arguments

Christian Couder [off-list ref] 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...

... the command silently exits with 1.

Le lundi 28 juillet 2008, Junio C Hamano a écrit :

Christian Couder [off-list ref] writes:

quoted

+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...

quoted

 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.

In "master" there is:

	rev1 = lookup_commit_reference(rev1key);
	rev2 = lookup_commit_reference(rev2key);
	if (!rev1 || !rev2)
		return 1;
	return show_merge_base(rev1, rev2, show_all);

so I think you found a bug in the current code.
I will post a patch to fix it soon.

It will "die" (with an error ùmessage) in case "lookup_commit_reference" 
returns NULL. I hope it's ok.

Thanks,
Christian.