v.input = v.input[copy(blk[:], v.input):]
		tr := Reader{r: bytes.NewReader(v.input)}
		got, err := tr.readOldGNUSparseMap(&hdr, &blk)
		if !slices.Equal(got, v.wantMap) {
			t.Errorf("test %d, readOldGNUSparseMap(): got %v, want %v", i, got, v.wantMap)
		}
		if err != v.wantErr {
			t.Errorf("test %d, readOldGNUSparseMap() = %v, want %v", i, err, v.wantErr)
		}
		if hdr.Size != v.wantSize {