io.Writer
	fileState

	ReadFrom(io.Reader) (int64, error)
}

// Flush finishes writing the current file's block padding.
// The current file must be fully written before Flush can be called.
//
// This is unnecessary as the next call to [Writer.WriteHeader] or [Writer.Close]
// will implicitly flush out the file's padding.
func (tw *Writer) Flush() error {
	if tw.err != nil {
		return tw.err
	}

	if err != nil {
		t.Fatal(err)
	}
	if buf.Len() > 0 {
		t.Fatalf("Unexpected %d bytes already in buffer", buf.Len())
	}
	if err := w.Flush(); err != nil {
		t.Fatal(err)
	}
	if buf.Len() == 0 {
		t.Fatal("No bytes written after Flush")
	}
}

func TestWriterDir(t *testing.T) {
	w := NewWriter(io.Discard)
	dw, err := w.Create("dir/")
	if err != nil {
		t.Fatal(err)
	}

// Writer implements buffering for an [io.Writer] object.
// If an error occurs writing to a [Writer], no more data will be
// accepted and all subsequent writes, and [Writer.Flush], will return the error.
// After all data has been written, the client should call the
// [Writer.Flush] method to guarantee all data has been forwarded to
// the underlying [io.Writer].
type Writer struct {
	err error
	buf []byte
	n   int
	wr  io.Writer
}

	n := len(data)
	f.buf.Write(data)
	// Flush to w until a potential match of exitRe
	b := f.buf.Bytes()
	match := f.exitRe.FindIndex(b)
	if match == nil {
		// Flush all of the buffer.
		_, err := f.w.Write(b)
		f.buf.Reset()
		if err != nil {
			return n, err
		}
	} else {
		// Flush up to the beginning of the (potential) match.
		_, err := f.w.Write(b[:match[0]])

	if w.cw.count != 0 {
		panic("zip: SetOffset called after data was written")
	}
	w.cw.count = n
}

// Flush flushes any buffered data to the underlying writer.
// Calling Flush is not normally necessary; calling Close is sufficient.
func (w *Writer) Flush() error {
	return w.cw.w.(*bufio.Writer).Flush()
}

// SetComment sets the end-of-central-directory comment field.
// It can only be called before [Writer.Close].

pkg syscall (openbsd-386-cgo), type Timespec struct, Sec int32
pkg syscall (openbsd-386-cgo), type Timeval struct, Sec int32
pkg syscall (openbsd-amd64), const CCR0_FLUSH = 16
pkg syscall (openbsd-amd64), const CCR0_FLUSH ideal-int
pkg syscall (openbsd-amd64), const CPUID_CFLUSH = 524288
pkg syscall (openbsd-amd64), const CPUID_CFLUSH ideal-int
pkg syscall (openbsd-amd64), const EFER_LMA = 1024

		}
		if _, err := tw.Write([]byte("Kilts")); err != ErrWriteAfterClose {
			t.Fatalf("Write() = %v, want %v", err, ErrWriteAfterClose)
		}
		if err := tw.Flush(); err != ErrWriteAfterClose {
			t.Fatalf("Flush() = %v, want %v", err, ErrWriteAfterClose)
		}
		if err := tw.Close(); err != nil {
			t.Fatalf("Close() = %v, want nil", err)
		}
	})

	t.Run("PrematureFlush", func(t *testing.T) {

	pList := new(obj.Plist)
	var ok bool
	testOut = new(strings.Builder) // The assembler writes test output to this buffer.
	ctxt.Bso = bufio.NewWriter(os.Stdout)
	ctxt.IsAsm = true
	defer ctxt.Bso.Flush()
	failed := false
	ctxt.DiagFunc = func(format string, args ...interface{}) {
		failed = true
		t.Errorf(format, args...)
	}
	pList.Firstpc, ok = parser.Parse()
	if !ok || failed {

# CL 134210043 archive/zip: add Writer.Flush, Brad Fitzpatrick <******@****.***>
pkg archive/zip, method (*Writer) Flush() error

# CL 97140043 compress/flate: add Reset() to allow reusing large buffers to compress multiple buffers, James Robinson <******@****.***>
pkg compress/flate, type Resetter interface { Reset }
pkg compress/flate, type Resetter interface, Reset(io.Reader, []uint8) error
pkg compress/zlib, type Resetter interface { Reset }

		for cname := range cmap {
			f2 := fmt.Sprintf("%s (%s)%s", f[:comma], cname, f[comma:])
			features = append(features, f2)
		}
	}

	bw := bufio.NewWriter(os.Stdout)
	defer bw.Flush()

	var required []string
	for _, file := range checkFiles {
		required = append(required, fileFeatures(file, needApproval(file))...)
	}
	for _, file := range nextFiles {