From b8b31a582d1fbcc015cce33f8a2e09411f4811ea Mon Sep 17 00:00:00 2001
From: tnextday <fw2k4@163.com>
Date: Wed, 13 Jan 2016 21:39:22 +0800
Subject: [PATCH] bug fix

---
 go/storage/volume_super_block.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/go/storage/volume_super_block.go b/go/storage/volume_super_block.go
index fc8c33900..7c1ea0eb2 100644
--- a/go/storage/volume_super_block.go
+++ b/go/storage/volume_super_block.go
@@ -33,7 +33,9 @@ func (s *SuperBlock) Bytes() []byte {
 	header := make([]byte, SuperBlockSize)
 	header[0] = byte(s.version)
 	header[1] = 0
-	s.Ttl.ToBytes(header[2:4])
+	if s.Ttl != nil {
+		s.Ttl.ToBytes(header[2:4])
+	}
 	util.Uint16toBytes(header[4:6], s.CompactRevision)
 	return header
 }