From 8d9e25dbddc189f4094e0f25a90f2b8a25deec9d Mon Sep 17 00:00:00 2001
From: Josh Hawn <josh.hawn@docker.com>
Date: Tue, 2 Dec 2014 15:23:49 -0800
Subject: [PATCH] Fix TarSum iteration test

I noticed that 3 of the tarsum test cases had expected a tarsum with
a sha256 hash of
  e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
As I've been working with sha256 quite a bit lately, it struck me that
this is the initial digest value for sha256, which means that no data
was processed. However, these tests *do* process data. It turns out that
there was a bug in the test handling code which did not wait for tarsum
to end completely. This patch corrects these test cases.

I'm unaware of anywhere else in the code base where this would be an issue,
though we definitily need to look out in the future to ensure we are
completing tarsum reads (waiting for EOF).

Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
---
 pkg/tarsum/tarsum_test.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkg/tarsum/tarsum_test.go b/pkg/tarsum/tarsum_test.go
index 5e7f042a2f..41e1b9b7c4 100644
--- a/pkg/tarsum/tarsum_test.go
+++ b/pkg/tarsum/tarsum_test.go
@@ -337,7 +337,7 @@ func TestIteration(t *testing.T) {
 		data        []byte
 	}{
 		{
-			"tarsum+sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
+			"tarsum+sha256:626c4a2e9a467d65c33ae81f7f3dedd4de8ccaee72af73223c4bc4718cbc7bbd",
 			Version0,
 			&tar.Header{
 				Name:     "file.txt",
@@ -349,7 +349,7 @@ func TestIteration(t *testing.T) {
 			[]byte(""),
 		},
 		{
-			"tarsum.dev+sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
+			"tarsum.dev+sha256:6ffd43a1573a9913325b4918e124ee982a99c0f3cba90fc032a65f5e20bdd465",
 			VersionDev,
 			&tar.Header{
 				Name:     "file.txt",
@@ -361,7 +361,7 @@ func TestIteration(t *testing.T) {
 			[]byte(""),
 		},
 		{
-			"tarsum.dev+sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
+			"tarsum.dev+sha256:b38166c059e11fb77bef30bf16fba7584446e80fcc156ff46d47e36c5305d8ef",
 			VersionDev,
 			&tar.Header{
 				Name:     "another.txt",
@@ -463,6 +463,7 @@ func renderSumForHeader(v Version, h *tar.Header, data []byte) (string, error) {
 	for {
 		hdr, err := tr.Next()
 		if hdr == nil || err == io.EOF {
+			// Signals the end of the archive.
 			break
 		}
 		if err != nil {
@@ -471,7 +472,6 @@ func renderSumForHeader(v Version, h *tar.Header, data []byte) (string, error) {
 		if _, err = io.Copy(ioutil.Discard, tr); err != nil {
 			return "", err
 		}
-		break // we're just reading one header ...
 	}
 	return ts.Sum(nil), nil
 }