bundle: don't leak an fd in case of early return

In successful operation `write_pack_data` will close the `bundle_fd`,
but when we exit early, we need to take care of the file descriptor
as well as the lock file ourselves. The lock file may be deleted at the
end of running the program, but we are in library code, so we should
not rely on that.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

bundle.c

@@ -435,12 +435,14 @@ int create_bundle(struct bundle_header *header, const char *path,
 
 	/* write prerequisites */
 	if (compute_and_write_prerequisites(bundle_fd, &revs, argc, argv))
-		return -1;
+		goto err;
 
 	argc = setup_revisions(argc, argv, &revs, NULL);
 
-	if (argc > 1)
-		return error(_("unrecognized argument: %s"), argv[1]);
+	if (argc > 1) {
+		error(_("unrecognized argument: %s"), argv[1]);
+		goto err;
+	}
 
 	object_array_remove_duplicates(&revs.pending);
 
@@ -448,17 +450,26 @@ int create_bundle(struct bundle_header *header, const char *path,
 	if (!ref_count)
 		die(_("Refusing to create empty bundle."));
 	else if (ref_count < 0)
-		return -1;
+		goto err;
 
 	/* write pack */
-	if (write_pack_data(bundle_fd, &revs))
-		return -1;
+	if (write_pack_data(bundle_fd, &revs)) {
+		bundle_fd = -1; /* already closed by the above call */
+		goto err;
+	}
 
 	if (!bundle_to_stdout) {
 		if (commit_lock_file(&lock))
 			die_errno(_("cannot create '%s'"), path);
 	}
 	return 0;
+err:
+	if (!bundle_to_stdout) {
+		if (0 <= bundle_fd)
+			close(bundle_fd);
+		rollback_lock_file(&lock);
+	}
+	return -1;
 }
 
 int unbundle(struct bundle_header *header, int bundle_fd, int flags)