mktag: convert to parse-options

Convert the "mktag" command to use parse-options.h instead of its own
ad-hoc argc handling. This doesn't matter much in practice since it
doesn't support any options, but removes another special-case in our
codebase, and makes it easier to add options to it in the future.

It does marginally improve the situation for programs that want to
execute git commands in a consistent manner and e.g. always use
--end-of-options. E.g. "gitaly" does that, and has a blacklist of
built-ins that don't support --end-of-options. This is one less
special case for it and other similar programs to support.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

builtin/mktag.c

@@ -1,10 +1,16 @@
 #include "builtin.h"
+#include "parse-options.h"
 #include "tag.h"
 #include "replace-object.h"
 #include "object-store.h"
 #include "fsck.h"
 #include "config.h"
 
+static char const * const builtin_mktag_usage[] = {
+	N_("git mktag"),
+	NULL
+};
+
 static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
 
 static int mktag_config(const char *var, const char *value, void *cb)
@@ -60,13 +66,17 @@ static int verify_object_in_tag(struct object_id *tagged_oid, int *tagged_type)
 
 int cmd_mktag(int argc, const char **argv, const char *prefix)
 {
+	static struct option builtin_mktag_options[] = {
+		OPT_END(),
+	};
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id tagged_oid;
 	int tagged_type;
 	struct object_id result;
 
-	if (argc != 1)
-		usage("git mktag");
+	argc = parse_options(argc, argv, NULL,
+			     builtin_mktag_options,
+			     builtin_mktag_usage, 0);
 
 	if (strbuf_read(&buf, 0, 0) < 0)
 		die_errno("could not read from stdin");

t/t3800-mktag.sh

@@ -45,6 +45,18 @@ test_expect_success 'setup' '
 	blob=$(git rev-parse --verify HEAD:B.t)
 '
 
+test_expect_success 'basic usage' '
+	cat >tag.sig <<-EOF &&
+	object $head
+	type commit
+	tag mytag
+	tagger T A Gger <[email protected]> 1206478233 -0500
+	EOF
+	git mktag <tag.sig &&
+	git mktag --end-of-options <tag.sig &&
+	test_expect_code 129 git mktag --unknown-option
+'
+
 ############################################################
 #  1. length check