Merge pull request #798 from restic/fix-797

Checker: Propagate errors properly

src/restic/checker/checker.go

@@ -80,6 +80,7 @@ func (c *Checker) LoadIndex() (hints []error, errs []error) {
 	debug.Log("Start")
 	type indexRes struct {
 		Index *repository.Index
+		err   error
 		ID    string
 	}
 
@@ -95,39 +96,40 @@ func (c *Checker) LoadIndex() (hints []error, errs []error) {
 			idx, err = repository.LoadIndexWithDecoder(c.repo, id, repository.DecodeOldIndex)
 		}
 
-		if err != nil {
-			return err
-		}
+		err = errors.Wrapf(err, "error loading index %v", id.Str())
 
 		select {
-		case indexCh <- indexRes{Index: idx, ID: id.String()}:
+		case indexCh <- indexRes{Index: idx, ID: id.String(), err: err}:
 		case <-done:
 		}
 
 		return nil
 	}
 
-	var perr error
 	go func() {
 		defer close(indexCh)
 		debug.Log("start loading indexes in parallel")
-		perr = repository.FilesInParallel(c.repo.Backend(), restic.IndexFile, defaultParallelism,
+		err := repository.FilesInParallel(c.repo.Backend(), restic.IndexFile, defaultParallelism,
 			repository.ParallelWorkFuncParseID(worker))
-		debug.Log("loading indexes finished, error: %v", perr)
+		debug.Log("loading indexes finished, error: %v", err)
+		if err != nil {
+			panic(err)
+		}
 	}()
 
 	done := make(chan struct{})
 	defer close(done)
 
-	if perr != nil {
-		errs = append(errs, perr)
-		return hints, errs
-	}
-
 	packToIndex := make(map[restic.ID]restic.IDSet)
 
 	for res := range indexCh {
-		debug.Log("process index %v", res.ID)
+		debug.Log("process index %v, err %v", res.ID, res.err)
+
+		if res.err != nil {
+			errs = append(errs, res.err)
+			continue
+		}
+
 		idxID, err := restic.ParseID(res.ID)
 		if err != nil {
 			errs = append(errs, errors.Errorf("unable to parse as index ID: %v", res.ID))
@@ -154,8 +156,6 @@ func (c *Checker) LoadIndex() (hints []error, errs []error) {
 		debug.Log("%d blobs processed", cnt)
 	}
 
-	debug.Log("done, error %v", perr)
-
 	debug.Log("checking for duplicate packs")
 	for packID := range c.packs {
 		debug.Log("  check pack %v: contained in %d indexes", packID.Str(), len(packToIndex[packID]))

src/restic/checker/checker_test.go

@@ -179,6 +179,48 @@ func TestUnreferencedBlobs(t *testing.T) {
 	test.Equals(t, unusedBlobsBySnapshot, blobs)
 }
 
+func TestModifiedIndex(t *testing.T) {
+	repodir, cleanup := test.Env(t, checkerTestData)
+	defer cleanup()
+
+	repo := repository.TestOpenLocal(t, repodir)
+
+	done := make(chan struct{})
+	defer close(done)
+
+	h := restic.Handle{
+		Type: restic.IndexFile,
+		Name: "90f838b4ac28735fda8644fe6a08dbc742e57aaf81b30977b4fefa357010eafd",
+	}
+	f, err := repo.Backend().Load(h, 0, 0)
+	test.OK(t, err)
+
+	// save the index again with a modified name so that the hash doesn't match
+	// the content any more
+	h2 := restic.Handle{
+		Type: restic.IndexFile,
+		Name: "80f838b4ac28735fda8644fe6a08dbc742e57aaf81b30977b4fefa357010eafd",
+	}
+	err = repo.Backend().Save(h2, f)
+	test.OK(t, err)
+
+	test.OK(t, f.Close())
+
+	chkr := checker.New(repo)
+	hints, errs := chkr.LoadIndex()
+	if len(errs) == 0 {
+		t.Fatalf("expected errors not found")
+	}
+
+	for _, err := range errs {
+		t.Logf("found expected error %v", err)
+	}
+
+	if len(hints) > 0 {
+		t.Errorf("expected no hints, got %v: %v", len(hints), hints)
+	}
+}
+
 var checkerDuplicateIndexTestData = filepath.Join("testdata", "duplicate-packs-in-index-test-repo.tar.gz")
 
 func TestDuplicatePacksInIndex(t *testing.T) {

src/restic/errors/wrap.go

@@ -18,3 +18,7 @@ var Errorf = errors.Errorf
 // Wrap wraps an error retrieved from outside of restic. Wrapped so that this
 // package does not appear in the stack trace.
 var Wrap = errors.Wrap
+
+// Wrapf returns an error annotating err with the format specifier. If err is
+// nil, Wrapf returns nil.
+var Wrapf = errors.Wrapf

src/restic/repository/repository.go

@@ -56,12 +56,12 @@ func (r *Repository) LoadAndDecrypt(t restic.FileType, id restic.ID) ([]byte, er
 	h := restic.Handle{Type: t, Name: id.String()}
 	buf, err := backend.LoadAll(r.be, h)
 	if err != nil {
-		debug.Log("error loading %v: %v", id.Str(), err)
+		debug.Log("error loading %v: %v", h, err)
 		return nil, err
 	}
 
 	if t != restic.ConfigFile && !restic.Hash(buf).Equal(id) {
-		return nil, errors.New("invalid data returned")
+		return nil, errors.Errorf("load %v: invalid data returned", h)
 	}
 
 	// decrypt