1 files changed, 58 insertions, 0 deletions
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
new file mode 100644
index 0000000000..76ba1d5881
--- /dev/null
+++ b/builtin/update-ref.c
@@ -0,0 +1,58 @@
+#include "cache.h"
+#include "refs.h"
+#include "builtin.h"
+#include "parse-options.h"
+
+static const char * const git_update_ref_usage[] = {
+	"git update-ref [options] -d <refname> [<oldval>]",
+	"git update-ref [options]    <refname> <newval> [<oldval>]",
+	NULL
+};
+
+int cmd_update_ref(int argc, const char **argv, const char *prefix)
+{
+	const char *refname, *oldval, *msg=NULL;
+	unsigned char sha1[20], oldsha1[20];
+	int delete = 0, no_deref = 0, flags = 0;
+	struct option options[] = {
+		OPT_STRING( 'm', NULL, &msg, "reason", "reason of the update"),
+		OPT_BOOLEAN('d', NULL, &delete, "deletes the reference"),
+		OPT_BOOLEAN( 0 , "no-deref", &no_deref,
+					"update <refname> not the one it points to"),
+		OPT_END(),
+	};
+
+	git_config(git_default_config, NULL);
+	argc = parse_options(argc, argv, prefix, options, git_update_ref_usage,
+			     0);
+	if (msg && !*msg)
+		die("Refusing to perform update with empty message.");
+
+	if (delete) {
+		if (argc < 1 || 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);
+		refname = argv[0];
+		value = argv[1];
+		oldval = argv[2];
+		if (get_sha1(value, sha1))
+			die("%s: not a valid SHA1", value);
+	}
+
+	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);
+
+	if (no_deref)
+		flags = REF_NODEREF;
+	if (delete)
+		return delete_ref(refname, oldval ? oldsha1 : NULL, flags);
+	else
+		return update_ref(msg, refname, sha1, oldval ? oldsha1 : NULL,
+				  flags, DIE_ON_ERR);
+}