package tar

import (
	"errors"
	"fmt"
	"io"
	"io/fs"
	"path"
	"sort"
	"strings"
	"time"
)

// Writer provides sequential writing of a tar archive.
// [Writer.WriteHeader] begins a new file with the provided [Header],
// and then Writer can be treated as an io.Writer to supply that file's data.
type Writer struct {
	w    io.Writer
	pad  int64      // Amount of padding to write after current file entry

	return runtime_arena_heapify(s).(T)
}

//go:linkname reflect_arena_New reflect.arena_New
func reflect_arena_New(a *Arena, typ any) any {
	return runtime_arena_arena_New(a.a, typ)
}

//go:linkname runtime_arena_newArena
func runtime_arena_newArena() unsafe.Pointer

//go:linkname runtime_arena_arena_New
func runtime_arena_arena_New(arena unsafe.Pointer, typ any) any

					t.Errorf("want=%q", data[0:len(written)])
					t.Errorf("have=%q", written)
				}
			}
		}
	}
}

func TestWriterAppend(t *testing.T) {
	got := new(bytes.Buffer)
	var want []byte
	rn := rand.New(rand.NewSource(0))
	w := NewWriterSize(got, 64)
	for i := 0; i < 100; i++ {
		// Obtain a buffer to append to.
		b := w.AvailableBuffer()
		if w.Available() != cap(b) {

			}
			if tok == scanner.EOF {
				p.errorf("unexpected EOF")
				return "", "", nil, false
			}
			// Split operands on comma. Also, the old syntax on x86 for a "register pair"
			// was AX:DX, for which the new syntax is DX, AX. Note the reordering.
			if tok == '\n' || tok == ';' || (nesting == 0 && (tok == ',' || tok == ':')) {
				if tok == ':' {
					// Remember this location so we can swap the operands below.
					if colon >= 0 {

				"A",
				"pkg syscall (darwin-amd64), type RawSockaddrInet6 struct",
			},
			ok:  false,
			out: "+pkg syscall, type RawSockaddrInet6 struct\n",
		},
	}
	for _, tt := range tests {
		buf := new(strings.Builder)
		gotOK := compareAPI(buf, tt.features, tt.required, tt.exception)
		if gotOK != tt.ok {
			t.Errorf("%s: ok = %v; want %v", tt.name, gotOK, tt.ok)
		}
		if got := buf.String(); got != tt.out {

	}
	swigDir := strings.TrimSpace(string(output))

	_, err = os.Stat(filepath.Join(swigDir, "go"))
	if err != nil {
		t.Skip("swig is missing Go support")
	}

	// Check that swig has a new enough version.
	// See https://golang.org/issue/22858.
	out, err := exec.Command(swig, "-version").CombinedOutput()
	if err != nil {
		t.Skipf("failed to get swig version:%s\n%s", err, string(out))
	}

For security reasons, only a limited set of flags are allowed, notably -D, -U, -I, and -l.
To allow additional flags, set CGO_CFLAGS_ALLOW to a regular expression
matching the new flags. To disallow flags that would otherwise be allowed,
set CGO_CFLAGS_DISALLOW to a regular expression matching arguments
that must be disallowed. In both cases the regular expression must match

func TestReadEmptyAtEOF(t *testing.T) {
	b := new(Buffer)
	slice := make([]byte, 0)
	n, err := b.Read(slice)
	if err != nil {
		t.Errorf("read error: %v", err)
	}
	if n != 0 {
		t.Errorf("wrong count; got %d want 0", n)
	}
}

func TestUnreadByte(t *testing.T) {
	b := new(Buffer)

	// check at EOF
	if err := b.UnreadByte(); err == nil {

	if err != nil {
		if list, ok := err.(scanner.ErrorList); ok {
			// If err is a scanner.ErrorList, its String will print just
			// the first error and then (+n more errors).
			// Instead, turn it into a new Error that will return
			// details for all the errors.
			for _, e := range list {
				fmt.Fprintln(os.Stderr, e)
			}
			os.Exit(2)
		}
		fatalf("parsing %s: %s", name, err)
	}
	return ast1
}

		testReadFile(t, src.File[i], &wt)
	}

	// make a new zip file copying the old compressed data.
	buf2 := new(bytes.Buffer)
	dst := NewWriter(buf2)
	for _, f := range src.File {
		if err := dst.Copy(f); err != nil {
			t.Fatal(err)
		}
	}
	if err := dst.Close(); err != nil {
		t.Fatal(err)
	}

	// read the new one back
	r, err := NewReader(bytes.NewReader(buf2.Bytes()), int64(buf2.Len()))