n := len(strings.TrimRight(s[:len(b)-1], "/"))
		b[n] = 0 // Replace trailing slash with NUL terminator
	}
}

// fitsInBase256 reports whether x can be encoded into n bytes using base-256
// encoding. Unlike octal encoding, base-256 encoding does not require that the
// string ends with a NUL character. Thus, all n bytes are available for output.
//
// If operating in binary mode, this assumes strict GNU binary mode; which means

	MOVB	$255, 4096(R4)        // ebff40000152
	MOVB	$-128, -524288(R5)    // eb8050008052
	MOVB	$1, -524289(R6)       // c0a1fff7ffff41aa60009201a000

	// RX (12-bit displacement) and RXY (20-bit displacement) instruction encoding (e.g: ST vs STY)
	MOVW	R1, 4095(R2)(R3)       // 50132fff
	MOVW	R1, 4096(R2)(R3)       // e31320000150
	MOVWZ	R1, 4095(R2)(R3)       // 50132fff
	MOVWZ	R1, 4096(R2)(R3)       // e31320000150

The [RuneLen] function returns the number of 16-bit words in
the UTF-16 encoding of the rune. It returns -1 if the rune

// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package zip

import (
	"bytes"
	"encoding/binary"
	"encoding/hex"
	"internal/obscuretestdata"
	"io"
	"io/fs"
	"os"
	"path/filepath"
	"reflect"
	"regexp"
	"strings"
	"testing"
	"testing/fstest"
	"time"
)

type ZipTest struct {
	Name     string

// equivalent to that from a range loop over the input as a string, which
// means that erroneous UTF-8 encodings translate to U+FFFD = "\xef\xbf\xbd".
// Because of the Scan interface, this makes it impossible for the client to
// distinguish correctly encoded replacement runes from encoding errors.
func ScanRunes(data []byte, atEOF bool) (advance int, token []byte, err error) {
	if atEOF && len(data) == 0 {

		f.NonUTF8 = false
	default:
		// Might be UTF-8, might be some other encoding; preserve existing flag.
		// Some ZIP writers use UTF-8 encoding without setting the UTF-8 flag.
		// Since it is impossible to always distinguish valid UTF-8 from some
		// other encoding (e.g., GBK or Shift-JIS), we trust the flag.
		f.NonUTF8 = f.Flags&0x800 == 0
	}

//	AccessTime        |    n/a | unlimited |     int89
//	ChangeTime        |    n/a | unlimited |     int89
//	Devmajor/Devminor | uint21 |    uint21 |    uint57
//	------------------+--------+-----------+----------
//	string encoding   |  ASCII |     UTF-8 |    binary
//	sub-second times  |     no |       yes |        no
//	sparse files      |     no |       yes |       yes
//
// The table's upper portion shows the [Header] fields, where each format reports

	Comment string

	// NonUTF8 indicates that Name and Comment are not encoded in UTF-8.
	//
	// By specification, the only other encoding permitted should be CP-437,
	// but historically many ZIP readers interpret Name and Comment as whatever
	// the system's local character encoding happens to be.
	//
	// This flag should only be set if the user intends to encode a non-portable

	{"3>>-4", "negative right shift count"},
	{"3>>(1<<63)", "negative right shift count"},
	{"(1<<63)>>2", "right shift of value with high bit set"},
	{"(1<<62)>>2", ""},
	{`'\x80'`, "illegal UTF-8 encoding for character constant"},
	{"(23*4", "missing closing paren"},
	{")23*4", "unexpected ) evaluating expression"},
	{"18446744073709551616", "value out of range"},
}

func TestBadExpr(t *testing.T) {

func (b *Buffer) WriteByte(c byte) error {
	b.lastRead = opInvalid
	m, ok := b.tryGrowByReslice(1)
	if !ok {
		m = b.grow(1)
	}
	b.buf[m] = c
	return nil
}

// WriteRune appends the UTF-8 encoding of Unicode code point r to the
// buffer, returning its length and an error, which is always nil but is
// included to match [bufio.Writer]'s WriteRune. The buffer is grown as needed;