Fix calls to repo/backend.List() everywhere

internal/index/index.go

@@ -115,13 +115,13 @@ func Load(ctx context.Context, repo restic.Repository, p *restic.Progress) (*Ind
 
 	index := newIndex()
 
-	for id := range repo.List(ctx, restic.IndexFile) {
+	err := repo.List(ctx, restic.IndexFile, func(id restic.ID, size int64) error {
 		p.Report(restic.Stat{Blobs: 1})
 
 		debug.Log("Load index %v", id.Str())
 		idx, err := loadIndexJSON(ctx, repo, id)
 		if err != nil {
-			return nil, err
+			return err
 		}
 
 		res := make(map[restic.ID]Pack)
@@ -144,12 +144,18 @@ func Load(ctx context.Context, repo restic.Repository, p *restic.Progress) (*Ind
 			}
 
 			if err = index.AddPack(jpack.ID, 0, entries); err != nil {
-				return nil, err
+				return err
 			}
 		}
 
 		results[id] = res
 		index.IndexIDs.Insert(id)
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
 	}
 
 	for superID, list := range supersedes {

internal/index/index_test.go

@@ -28,7 +28,7 @@ func createFilledRepo(t testing.TB, snapshots int, dup float32) (restic.Reposito
 }
 
 func validateIndex(t testing.TB, repo restic.Repository, idx *Index) {
-	for id := range repo.List(context.TODO(), restic.DataFile) {
+	err := repo.List(context.TODO(), restic.DataFile, func(id restic.ID, size int64) error {
 		p, ok := idx.Packs[id]
 		if !ok {
 			t.Errorf("pack %v missing from index", id.Str())
@@ -37,6 +37,11 @@ func validateIndex(t testing.TB, repo restic.Repository, idx *Index) {
 		if !p.ID.Equal(id) {
 			t.Errorf("pack %v has invalid ID: want %v, got %v", id.Str(), id, p.ID)
 		}
+		return nil
+	})
+
+	if err != nil {
+		t.Fatal(err)
 	}
 }
 
@@ -308,7 +313,14 @@ func TestIndexAddRemovePack(t *testing.T) {
 		t.Fatalf("Load() returned error %v", err)
 	}
 
-	packID := <-repo.List(context.TODO(), restic.DataFile)
+	var packID restic.ID
+	err = repo.List(context.TODO(), restic.DataFile, func(id restic.ID, size int64) error {
+		packID = id
+		return nil
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	t.Logf("selected pack %v", packID.Str())