remote: run "remote rm" argv through parse_options()

The "git remote rm" command's option parsing is fairly primitive: it
insists on a single argument, which it treats as the remote name, and
displays a usage message otherwise.

This is OK, and maybe even convenient, as you could run:

  git remote rm --foo

to drop a remote named "--foo". But it's also weirdly unlike most of the
rest of Git, which would complain that there is no option "--foo". The
right way to spell it by our conventions is:

  git remote rm -- --foo

but this doesn't currently work.

So let's bring the command in line with the rest of Git (including its
sibling subcommands!) by feeding argv to parse_options(). We already
have an empty options array for the usage helper.

Note that we have to adjust the argc index down by one, as
parse_options() eats the program name from the start of the array.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/remote.c

@@ -862,12 +862,14 @@ static int rm(int argc, const char **argv, const char *prefix)
 	cb_data.skipped = &skipped;
 	cb_data.keep = &known_remotes;
 
-	if (argc != 2)
+	argc = parse_options(argc, argv, prefix, options,
+			     builtin_remote_rm_usage, 0);
+	if (argc != 1)
 		usage_with_options(builtin_remote_rm_usage, options);
 
-	remote = remote_get(argv[1]);
+	remote = remote_get(argv[0]);
 	if (!remote_is_configured(remote, 1)) {
-		error(_("No such remote: '%s'"), argv[1]);
+		error(_("No such remote: '%s'"), argv[0]);
 		exit(2);
 	}