Commit 35220534 authored by Joe Tsai's avatar Joe Tsai Committed by Joe Tsai

archive/zip: only use Extended Timestamp on non-zero MS-DOS timestamps

We should preserve the fact that a roundtrip read on fields with the zero
value should remain the zero for those that are reasonable to stay that way.
If the zero value for a MS-DOS timestamp was used, then it is sensible for
that zero value to also be read back later.

Fixes #17403

Change-Id: I32c3915eab180e91ddd2499007374f7b85f0bd76
Reviewed-on: https://go-review.googlesource.com/30811
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarBrad Fitzpatrick <bradfitz@golang.org>
parent 303b69fe
......@@ -65,7 +65,7 @@ const (
zip64ExtraId = 0x0001 // zip64 Extended Information Extra Field
ntfsExtraId = 0x000a // NTFS Extra Field
unixExtraId = 0x000d // UNIX Extra Field
exttsExtraId = 0x5455 // Extra Timestamp Extra Field
exttsExtraId = 0x5455 // Extended Timestamp Extra Field
)
// FileHeader describes a file within a zip file.
......
......@@ -99,14 +99,17 @@ func (w *Writer) Close() error {
b.uint32(h.UncompressedSize)
}
mt := uint32(h.FileHeader.ModTime().Unix())
var mbuf [9]byte // 2x uint16 + uint8 + uint32
eb := writeBuf(mbuf[:])
eb.uint16(exttsExtraId)
eb.uint16(5) // size = uint8 + uint32
eb.uint8(1) // flags = modtime
eb.uint32(mt) // ModTime
h.Extra = append(h.Extra, mbuf[:]...)
// use Extended Timestamp Extra Field.
if h.ModifiedTime != 0 || h.ModifiedDate != 0 {
mt := uint32(h.ModTime().Unix())
var mbuf [9]byte // 2x uint16 + uint8 + uint32
eb := writeBuf(mbuf[:])
eb.uint16(exttsExtraId)
eb.uint16(5) // size = uint8 + uint32
eb.uint8(1) // flags = modtime
eb.uint32(mt) // ModTime
h.Extra = append(h.Extra, mbuf[:]...)
}
b.uint16(uint16(len(h.Name)))
b.uint16(uint16(len(h.Extra)))
......
......@@ -13,6 +13,7 @@ import (
"internal/testenv"
"io"
"io/ioutil"
"reflect"
"sort"
"strings"
"testing"
......@@ -111,6 +112,44 @@ func TestFileHeaderRoundTrip64(t *testing.T) {
testHeaderRoundTrip(fh, uint32max, fh.UncompressedSize64, t)
}
func TestZeroFileRoundTrip(t *testing.T) {
var b bytes.Buffer
w := NewWriter(&b)
if _, err := w.Create(""); err != nil {
t.Fatal(err)
}
if err := w.Close(); err != nil {
t.Fatal(err)
}
r, err := NewReader(bytes.NewReader(b.Bytes()), int64(b.Len()))
if err != nil {
t.Fatal(err)
}
// Verify that fields that should reasonably be the zero value stays
// as the zero value.
var want FileHeader
if len(r.File) != 1 {
t.Fatalf("len(r.File) = %d, want 1", len(r.File))
}
fh := r.File[0].FileHeader
got := FileHeader{
Name: fh.Name,
ModifiedTime: fh.ModifiedTime,
ModifiedDate: fh.ModifiedDate,
UncompressedSize: fh.UncompressedSize,
UncompressedSize64: fh.UncompressedSize64,
ExternalAttrs: fh.ExternalAttrs,
Comment: fh.Comment,
}
if len(fh.Extra) > 0 {
got.Extra = fh.Extra
}
if !reflect.DeepEqual(got, want) {
t.Errorf("FileHeader mismatch:\ngot %#v\nwant %#v", got, want)
}
}
type repeatedByte struct {
off int64
b byte
......
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