1 files changed, 108 insertions, 0 deletions
diff --git a/builtin/mktag.c b/builtin/mktag.c
new file mode 100644
index 0000000..5d22909
--- /dev/null
+++ b/builtin/mktag.c
@@ -0,0 +1,108 @@
+#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[] = {
+	"git mktag",
+	NULL
+};
+static int option_strict = 1;
+
+static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
+
+static int mktag_fsck_error_func(struct fsck_options *o,
+				 const struct object_id *oid,
+				 enum object_type object_type,
+				 enum fsck_msg_type msg_type,
+				 enum fsck_msg_id msg_id,
+				 const char *message)
+{
+	switch (msg_type) {
+	case FSCK_WARN:
+		if (!option_strict) {
+			fprintf_ln(stderr, _("warning: tag input does not pass fsck: %s"), message);
+			return 0;
+
+		}
+		/* fallthrough */
+	case FSCK_ERROR:
+		/*
+		 * We treat both warnings and errors as errors, things
+		 * like missing "tagger" lines are "only" warnings
+		 * under fsck, we've always considered them an error.
+		 */
+		fprintf_ln(stderr, _("error: tag input does not pass fsck: %s"), message);
+		return 1;
+	default:
+		BUG(_("%d (FSCK_IGNORE?) should never trigger this callback"),
+		    msg_type);
+	}
+}
+
+static int verify_object_in_tag(struct object_id *tagged_oid, int *tagged_type)
+{
+	int ret;
+	enum object_type type;
+	unsigned long size;
+	void *buffer;
+	const struct object_id *repl;
+
+	buffer = read_object_file(tagged_oid, &type, &size);
+	if (!buffer)
+		die(_("could not read tagged object '%s'"),
+		    oid_to_hex(tagged_oid));
+	if (type != *tagged_type)
+		die(_("object '%s' tagged as '%s', but is a '%s' type"),
+		    oid_to_hex(tagged_oid),
+		    type_name(*tagged_type), type_name(type));
+
+	repl = lookup_replace_object(the_repository, tagged_oid);
+	ret = check_object_signature(the_repository, repl, buffer, size,
+				     *tagged_type);
+	free(buffer);
+
+	return ret;
+}
+
+int cmd_mktag(int argc, const char **argv, const char *prefix)
+{
+	static struct option builtin_mktag_options[] = {
+		OPT_BOOL(0, "strict", &option_strict,
+			 N_("enable more strict checking")),
+		OPT_END(),
+	};
+	struct strbuf buf = STRBUF_INIT;
+	struct object_id tagged_oid;
+	int tagged_type;
+	struct object_id result;
+
+	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"));
+
+	fsck_options.error_func = mktag_fsck_error_func;
+	fsck_set_msg_type_from_ids(&fsck_options, FSCK_MSG_EXTRA_HEADER_ENTRY,
+				   FSCK_WARN);
+	/* config might set fsck.extraHeaderEntry=* again */
+	git_config(git_fsck_config, &fsck_options);
+	if (fsck_tag_standalone(NULL, buf.buf, buf.len, &fsck_options,
+				&tagged_oid, &tagged_type))
+		die(_("tag on stdin did not pass our strict fsck check"));
+
+	if (verify_object_in_tag(&tagged_oid, &tagged_type) < 0)
+		die(_("tag on stdin did not refer to a valid object"));
+
+	if (write_object_file(buf.buf, buf.len, OBJ_TAG, &result) < 0)
+		die(_("unable to write tag file"));
+
+	strbuf_release(&buf);
+	puts(oid_to_hex(&result));
+	return 0;
+}