// 0xFFFFFFFF, but not before.
func TestZip64DirectoryOffset(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping in short mode")
	}
	t.Parallel()
	const filename = "huge.txt"
	gen := func(wantOff uint64) func(*Writer) {
		return func(w *Writer) {
			w.testHookCloseSizeOffset = func(size, off uint64) {
				if off != wantOff {