From 6e399e8f507669ffc8f16a596320e73ab634055d Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Tue, 12 Jul 2016 16:42:54 +1000
Subject: [PATCH] Add test for issue #97

---
 issue97_test.go | 26 ++++++++++++++++++++++++++
 torrent.go      | 22 +++++++++++++---------
 2 files changed, 39 insertions(+), 9 deletions(-)
 create mode 100644 issue97_test.go

diff --git a/issue97_test.go b/issue97_test.go
new file mode 100644
index 00000000..3f4e16d2
--- /dev/null
+++ b/issue97_test.go
@@ -0,0 +1,26 @@
+package torrent
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/anacrolix/torrent/internal/testutil"
+	"github.com/anacrolix/torrent/storage"
+)
+
+func TestHashPieceAfterStorageClosed(t *testing.T) {
+	td, err := ioutil.TempDir("", "")
+	require.NoError(t, err)
+	defer os.RemoveAll(td)
+	cs := storage.NewFile(td)
+	tt := &Torrent{}
+	tt.info = &testutil.GreetingMetaInfo().Info
+	tt.makePieces()
+	tt.storage, err = cs.OpenTorrent(tt.info)
+	require.NoError(t, err)
+	require.NoError(t, tt.storage.Close())
+	tt.hashPiece(0)
+}
diff --git a/torrent.go b/torrent.go
index cb17f49b..216ebbc1 100644
--- a/torrent.go
+++ b/torrent.go
@@ -205,6 +205,18 @@ func infoPieceHashes(info *metainfo.Info) (ret []string) {
 	return
 }
 
+func (t *Torrent) makePieces() {
+	hashes := infoPieceHashes(&t.info.Info)
+	t.pieces = make([]piece, len(hashes))
+	for i, hash := range hashes {
+		piece := &t.pieces[i]
+		piece.t = t
+		piece.index = i
+		piece.noPendingWrites.L = &piece.pendingWritesMutex
+		missinggo.CopyExact(piece.Hash[:], hash)
+	}
+}
+
 // Called when metadata for a torrent becomes available.
 func (t *Torrent) setInfoBytes(b []byte) error {
 	if t.haveInfo() {
@@ -237,15 +249,7 @@ func (t *Torrent) setInfoBytes(b []byte) error {
 	}
 	t.metadataBytes = b
 	t.metadataCompletedChunks = nil
-	hashes := infoPieceHashes(&t.info.Info)
-	t.pieces = make([]piece, len(hashes))
-	for i, hash := range hashes {
-		piece := &t.pieces[i]
-		piece.t = t
-		piece.index = i
-		piece.noPendingWrites.L = &piece.pendingWritesMutex
-		missinggo.CopyExact(piece.Hash[:], hash)
-	}
+	t.makePieces()
 	for _, conn := range t.conns {
 		if err := conn.setNumPieces(t.numPieces()); err != nil {
 			log.Printf("closing connection: %s", err)