Clean up builtin-update-ref's option parsing

builtin-update-ref's option parsing was somewhat tricky to follow,
especially if the -d option was given. This patch cleans it upp a bit,
at the expense of making it a bit longer.

Signed-off-by: Karl Hasselström <kha@treskal.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 15 deletions

diff --git a/builtin-update-ref.c b/builtin-update-ref.c
index 93c1271..1e714a3 100644
--- a/builtin-update-ref.c
+++ b/builtin-update-ref.c
@@ -11,7 +11,7 @@ static const char * const git_update_ref_usage[] = {
 
 int cmd_update_ref(int argc, const char **argv, const char *prefix)
 {
-	const char *refname, *value, *oldval, *msg=NULL;
+	const char *refname, *oldval, *msg=NULL;
 	unsigned char sha1[20], oldsha1[20];
 	int delete = 0, no_deref = 0;
 	struct option options[] = {
@@ -27,25 +27,29 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 	if (msg && !*msg)
 		die("Refusing to perform update with empty message.");
 
-	if (argc < 2 || argc > 3)
-		usage_with_options(git_update_ref_usage, options);
-	refname = argv[0];
-	value   = argv[1];
-	oldval  = argv[2];
-
-	if (get_sha1(value, sha1))
-		die("%s: not a valid SHA1", value);
-
 	if (delete) {
-		if (oldval)
+		if (argc != 2)
+			usage_with_options(git_update_ref_usage, options);
+		refname = argv[0];
+		oldval = argv[1];
+	} else {
+		const char *value;
+		if (argc < 2 || argc > 3)
 			usage_with_options(git_update_ref_usage, options);
-		return delete_ref(refname, sha1);
+		refname = argv[0];
+		value = argv[1];
+		oldval = argv[2];
+		if (get_sha1(value, sha1))
+			die("%s: not a valid SHA1", value);
 	}
 
-	hashclr(oldsha1);
+	hashclr(oldsha1); /* all-zero hash in case oldval is the empty string */
 	if (oldval && *oldval && get_sha1(oldval, oldsha1))
 		die("%s: not a valid old SHA1", oldval);
 
-	return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
-			  no_deref ? REF_NODEREF : 0, DIE_ON_ERR);
+	if (delete)
+		return delete_ref(refname, oldsha1);
+	else
+		return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
+				  no_deref ? REF_NODEREF : 0, DIE_ON_ERR);
 }