}
		t.Fatalf("expect read %d bytes but got %d", wroteBytes, readBytes)
	}
	if readHash.Sum32() != wroteHash.Sum32() {
		t.Fatalf("expect read hash 0x%08x but got 0x%08x", readHash.Sum32(), wroteHash.Sum32())
	}
}

func TestRingBuffer_BlockingBig(t *testing.T) {
	// Typical runtime is ~5-10s.
	defer timeout(60 * time.Second)()
	const debug = false

				} else {
					err = err1
				}
			} else if r.hash.Sum32() != r.f.CRC32 {
				err = ErrChecksum
			}
		} else {
			// If there's not a data descriptor, we still compare
			// the CRC32 of what we've read against the file header
			// or TOC's CRC32, if it seems like it was set.
			if r.f.CRC32 != 0 && r.hash.Sum32() != r.f.CRC32 {
				err = ErrChecksum
			}
		}
	}
	r.err = err

	w.closed = true
	if w.raw {
		return w.writeDataDescriptor()
	}
	if err := w.comp.Close(); err != nil {
		return err
	}

	// update FileHeader
	fh := w.header.FileHeader
	fh.CRC32 = w.crc32.Sum32()
	fh.CompressedSize64 = uint64(w.compCount.count)
	fh.UncompressedSize64 = uint64(w.rawCount.count)

	if fh.isZip64() {
		fh.CompressedSize = uint32max
		fh.UncompressedSize = uint32max

		}
	}
}

// fakeHash32 is a dummy Hash32 that always returns 0.
type fakeHash32 struct {
	hash.Hash32
}

func (fakeHash32) Write(p []byte) (int, error) { return len(p), nil }
func (fakeHash32) Sum32() uint32               { return 0 }

func TestZip64(t *testing.T) {
	if testing.Short() {
		t.Skip("slow test; skipping")
	}
	t.Parallel()
	const size = 1 << 32 // before the "END\n" part

pkg hash, type Hash32 interface { BlockSize, Reset, Size, Sum, Sum32, Write }
pkg hash, type Hash32 interface, BlockSize() int
pkg hash, type Hash32 interface, Reset()
pkg hash, type Hash32 interface, Size() int
pkg hash, type Hash32 interface, Sum([]uint8) []uint8
pkg hash, type Hash32 interface, Sum32() uint32
pkg hash, type Hash32 interface, Write([]uint8) (int, error)