From ae3a0ec27e26f4a725d7b58ea15410f8820d114c Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Tue, 19 Jan 2016 08:20:23 +0000
Subject: [PATCH] b2: Don't re-read the SHA1 if we already have it

---
 b2/b2.go | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/b2/b2.go b/b2/b2.go
index e76b61634..6cf6fa115 100644
--- a/b2/b2.go
+++ b/b2/b2.go
@@ -614,11 +614,12 @@ func (o *Object) Hash(t fs.HashType) (string, error) {
 	if t != fs.HashSHA1 {
 		return "", fs.ErrHashUnsupported
 	}
-
-	// Error is logged in readFileMetadata
-	err := o.readFileMetadata()
-	if err != nil {
-		return "", err
+	if o.sha1 == "" {
+		// Error is logged in readFileMetadata
+		err := o.readFileMetadata()
+		if err != nil {
+			return "", err
+		}
 	}
 	return o.sha1, nil
 }