1 files changed, 57 insertions, 0 deletions
diff --git a/builtin/symbolic-ref.c b/builtin/symbolic-ref.c
new file mode 100644
index 0000000..ca855a5
--- /dev/null
+++ b/builtin/symbolic-ref.c
@@ -0,0 +1,57 @@
+#include "builtin.h"
+#include "cache.h"
+#include "refs.h"
+#include "parse-options.h"
+
+static const char * const git_symbolic_ref_usage[] = {
+	"git symbolic-ref [options] name [ref]",
+	NULL
+};
+
+static void check_symref(const char *HEAD, int quiet)
+{
+	unsigned char sha1[20];
+	int flag;
+	const char *refs_heads_master = resolve_ref(HEAD, sha1, 0, &flag);
+
+	if (!refs_heads_master)
+		die("No such ref: %s", HEAD);
+	else if (!(flag & REF_ISSYMREF)) {
+		if (!quiet)
+			die("ref %s is not a symbolic ref", HEAD);
+		else
+			exit(1);
+	}
+	puts(refs_heads_master);
+}
+
+int cmd_symbolic_ref(int argc, const char **argv, const char *prefix)
+{
+	int quiet = 0;
+	const char *msg = NULL;
+	struct option options[] = {
+		OPT__QUIET(&quiet),
+		OPT_STRING('m', NULL, &msg, "reason", "reason of the update"),
+		OPT_END(),
+	};
+
+	git_config(git_default_config, NULL);
+	argc = parse_options(argc, argv, prefix, options,
+			     git_symbolic_ref_usage, 0);
+	if (msg &&!*msg)
+		die("Refusing to perform update with empty message");
+	switch (argc) {
+	case 1:
+		check_symref(argv[0], quiet);
+		break;
+	case 2:
+		if (!strcmp(argv[0], "HEAD") &&
+		    prefixcmp(argv[1], "refs/"))
+			die("Refusing to point HEAD outside of refs/");
+		create_symref(argv[0], argv[1], msg);
+		break;
+	default:
+		usage_with_options(git_symbolic_ref_usage, options);
+	}
+	return 0;
+}