copy: fix nil pointer dereference when corrupted on transfer with nil dst

backend/local/local_internal_test.go

@@ -76,6 +76,23 @@ func TestUpdatingCheck(t *testing.T) {
 
 }
 
+// Test corrupted on transfer
+// should error due to size/hash mismatch
+func TestVerifyCopy(t *testing.T) {
+	r := fstest.NewRun(t)
+	filePath := "sub dir/local test"
+	r.WriteFile(filePath, "some content", time.Now())
+	src, err := r.Flocal.NewObject(context.Background(), filePath)
+	require.NoError(t, err)
+	src.(*Object).fs.opt.NoCheckUpdated = true
+
+	for i := 0; i < 100; i++ {
+		go r.WriteFile(src.Remote(), fmt.Sprintf("some new content %d", i), src.ModTime(context.Background()))
+	}
+	_, err = operations.Copy(context.Background(), r.Fremote, nil, filePath+"2", src)
+	assert.Error(t, err)
+}
+
 func TestSymlink(t *testing.T) {
 	ctx := context.Background()
 	r := fstest.NewRun(t)

fs/operations/copy.go

@@ -266,14 +266,14 @@ func (c *copy) manualCopy(ctx context.Context) (actionTaken string, newDst fs.Ob
 func (c *copy) verify(ctx context.Context, newDst fs.Object) (err error) {
 	// Verify sizes are the same after transfer
 	if sizeDiffers(ctx, c.src, newDst) {
-		return fmt.Errorf("corrupted on transfer: sizes differ src(%s) %d vs dst(%s) %d", c.src.Fs(), c.src.Size(), c.dst.Fs(), c.dst.Size())
+		return fmt.Errorf("corrupted on transfer: sizes differ src(%s) %d vs dst(%s) %d", c.src.Fs(), c.src.Size(), newDst.Fs(), newDst.Size())
 	}
 	// Verify hashes are the same after transfer - ignoring blank hashes
 	if c.hashType != hash.None {
 		// checkHashes has logs and counts errors
 		equal, _, srcSum, dstSum, _ := checkHashes(ctx, c.src, newDst, c.hashType)
 		if !equal {
-			return fmt.Errorf("corrupted on transfer: %v hashes differ src(%s) %q vs dst(%s) %q", c.hashType, c.src.Fs(), srcSum, c.dst.Fs(), dstSum)
+			return fmt.Errorf("corrupted on transfer: %v hashes differ src(%s) %q vs dst(%s) %q", c.hashType, c.src.Fs(), srcSum, newDst.Fs(), dstSum)
 		}
 	}
 	return nil