t.Errorf("expected error %v, got %v", test.err, err)
		}
	}
}

func BenchmarkReadString(b *testing.B) {
	const n = 32 << 10

	data := make([]byte, n)
	data[n-1] = 'x'
	b.SetBytes(int64(n))
	for i := 0; i < b.N; i++ {
		buf := NewBuffer(data)
		_, err := buf.ReadString('x')
		if err != nil {
			b.Fatal(err)
		}
	}
}

func TestGrow(t *testing.T) {
	x := []byte{'x'}

	// if C.free is needed).
	func C.CBytes([]byte) unsafe.Pointer

	// C string to Go string
	func C.GoString(*C.char) string

	// C data with explicit length to Go string
	func C.GoStringN(*C.char, C.int) string

	// C data with explicit length to Go []byte
	func C.GoBytes(unsafe.Pointer, C.int) []byte

As a special case, C.malloc does not call the C library malloc directly

// that the file has no data in it, which is rather odd.
//
// As an example, if the underlying raw file contains the 10-byte data:
//
//	var compactFile = "abcdefgh"
//
// And the sparse map has the following entries:
//
//	var spd sparseDatas = []sparseEntry{
//		{Offset: 2,  Length: 5},  // Data fragment for 2..6
//		{Offset: 18, Length: 3},  // Data fragment for 18..20
//	}

		t.Parallel()
		if !generatesZip64(t, gen(0xffff)) {
			t.Error("expected zip64")
		}
	})
}

// suffixSaver is an io.Writer & io.ReaderAt that remembers the last 0
// to 'keep' bytes of data written to it. Call Suffix to get the
// suffix bytes.
type suffixSaver struct {
	keep  int
	buf   []byte
	start int
	size  int64
}

func (ss *suffixSaver) Size() int64 { return ss.size }

</p>

<p>
A data race is defined as
a write to a memory location happening concurrently with another read or write to that same location,
unless all the accesses involved are atomic data accesses as provided by the <code>sync/atomic</code> package.
As noted already, programmers are strongly encouraged to use appropriate synchronization
to avoid data races.
In the absence of data races, Go programs behave as if all the goroutines

}

// SetOffset sets the offset of the beginning of the zip data within the
// underlying writer. It should be used when the zip data is appended to an
// existing file, such as a binary executable.
// It must be called before any data is written.
func (w *Writer) SetOffset(n int64) {
	if w.cw.count != 0 {
		panic("zip: SetOffset called after data was written")
	}
	w.cw.count = n
}

	var gnuLongName, gnuLongLink string

	// Externally, Next iterates through the tar archive as if it is a series of
	// files. Internally, the tar format often uses fake "files" to add meta
	// data that describes the next file. These meta data "files" should not
	// normally be visible to the outside. As such, this loop iterates through
	// one or more "header files" until it finds a "normal file".
	format := FormatUSTAR | FormatPAX | FormatGNU

		t.Errorf("Header mismatch.\n got %+v\nwant %+v", rHdr, hdr)
	}
	rData, err := io.ReadAll(tr)
	if err != nil {
		t.Fatalf("Read: %v", err)
	}
	if !bytes.Equal(rData, data) {
		t.Errorf("Data mismatch.\n got %q\nwant %q", rData, data)
	}
}

type headerRoundTripTest struct {
	h  *Header
	fm fs.FileMode
}

func TestHeaderRoundTrip(t *testing.T) {
	vectors := []headerRoundTripTest{{