Merge pull request #748 from restic/fix-747

rest backend: Do not close the reader

src/restic/backend/rest/rest.go

@@ -80,6 +80,10 @@ func (b *restBackend) Save(h restic.Handle, rd io.Reader) (err error) {
 		return err
 	}
 
+	// make sure that client.Post() cannot close the reader by wrapping it in
+	// backend.Closer, which has a noop method.
+	rd = backend.Closer{Reader: rd}
+
 	<-b.connChan
 	resp, err := b.client.Post(restPath(b.url, h), "binary/octet-stream", rd)
 	b.connChan <- struct{}{}

src/restic/backend/test/tests.go

@@ -6,8 +6,10 @@ import (
 	"io"
 	"io/ioutil"
 	"math/rand"
+	"os"
 	"reflect"
 	"restic"
+	"restic/errors"
 	"sort"
 	"strings"
 	"testing"
@@ -271,6 +273,16 @@ func TestLoad(t testing.TB) {
 	test.OK(t, b.Remove(restic.DataFile, id.String()))
 }
 
+type errorCloser struct {
+	io.Reader
+	t testing.TB
+}
+
+func (ec errorCloser) Close() error {
+	ec.t.Error("forbidden method close was called")
+	return errors.New("forbidden method close was called")
+}
+
 // TestSave tests saving data in the backend.
 func TestSave(t testing.TB) {
 	b := open(t)
@@ -312,6 +324,46 @@ func TestSave(t testing.TB) {
 			t.Fatalf("error removing item: %v", err)
 		}
 	}
+
+	// test saving from a tempfile
+	tmpfile, err := ioutil.TempFile("", "restic-backend-save-test-")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	length := rand.Intn(1<<23) + 200000
+	data := test.Random(23, length)
+	copy(id[:], data)
+
+	if _, err = tmpfile.Write(data); err != nil {
+		t.Fatal(err)
+	}
+
+	if _, err = tmpfile.Seek(0, 0); err != nil {
+		t.Fatal(err)
+	}
+
+	h := restic.Handle{Type: restic.DataFile, Name: id.String()}
+
+	// wrap the tempfile in an errorCloser, so we can detect if the backend
+	// closes the reader
+	err = b.Save(h, errorCloser{t: t, Reader: tmpfile})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err = tmpfile.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	if err = os.Remove(tmpfile.Name()); err != nil {
+		t.Fatal(err)
+	}
+
+	err = b.Remove(h.Type, h.Name)
+	if err != nil {
+		t.Fatalf("error removing item: %v", err)
+	}
 }
 
 var filenameTests = []struct {

src/restic/repository/packer_manager.go

@@ -29,20 +29,6 @@ type Packer struct {
 	tmpfile *os.File
 }
 
-// Finalize finalizes the pack.Packer and then closes the tempfile.
-func (p *Packer) Finalize() (uint, error) {
-	n, err := p.Packer.Finalize()
-	if err != nil {
-		return n, err
-	}
-
-	if err = p.tmpfile.Close(); err != nil {
-		return n, err
-	}
-
-	return n, nil
-}
-
 // packerManager keeps a list of open packs and creates new on demand.
 type packerManager struct {
 	be      Saver

src/restic/repository/packer_manager_test.go

@@ -47,25 +47,19 @@ func randomID(rd io.Reader) restic.ID {
 
 const maxBlobSize = 1 << 20
 
-func saveFile(t testing.TB, be Saver, filename string, id restic.ID) {
+func saveFile(t testing.TB, be Saver, f *os.File, id restic.ID) {
-	f, err := os.Open(filename)
-	if err != nil {
-		t.Fatal(err)
-	}
-
 	h := restic.Handle{Type: restic.DataFile, Name: id.String()}
 	t.Logf("save file %v", h)
 
-	if err = be.Save(h, f); err != nil {
+	if err := be.Save(h, f); err != nil {
 		t.Fatal(err)
 	}
 
-	if err = f.Close(); err != nil {
+	if err := f.Close(); err != nil {
 		t.Fatal(err)
 	}
 
-	err = os.Remove(filename)
+	if err := os.Remove(f.Name()); err != nil {
-	if err != nil {
 		t.Fatal(err)
 	}
 }
@@ -104,8 +98,12 @@ func fillPacks(t testing.TB, rnd *randReader, be Saver, pm *packerManager, buf [
 			t.Fatal(err)
 		}
 
+		if _, err = packer.tmpfile.Seek(0, 0); err != nil {
+			t.Fatal(err)
+		}
+
 		packID := restic.IDFromHash(packer.hw.Sum(nil))
-		saveFile(t, be, packer.tmpfile.Name(), packID)
+		saveFile(t, be, packer.tmpfile, packID)
 	}
 
 	return bytes
@@ -121,7 +119,7 @@ func flushRemainingPacks(t testing.TB, rnd *randReader, be Saver, pm *packerMana
 			bytes += int(n)
 
 			packID := restic.IDFromHash(packer.hw.Sum(nil))
-			saveFile(t, be, packer.tmpfile.Name(), packID)
+			saveFile(t, be, packer.tmpfile, packID)
 		}
 	}
 

src/restic/test/helpers.go

@@ -79,7 +79,7 @@ func Random(seed, count int) []byte {
 
 		for j := range data {
 			cur := i + j
-			if len(p) >= cur {
+			if cur >= len(p) {
 				break
 			}
 			p[cur] = data[j]