qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-23 06:50:05 -07:00
Code Releases Activity

image/jpeg: don't assume that an ensureNBits failure implies that we can

Browse Source 
call unreadByteStuffedByte.

If ensureNBits was due to an io.EOF that was translated to
jpeg.errShortHuffmanData, then we may have read no bytes, so there is no
byte-stuffed-byte to unread.

Fixes #10387

Change-Id: I39a3842590c6cef2aa48943288d52f603338b44d
Reviewed-on: https://go-review.googlesource.com/8841
Reviewed-by: Rob Pike <r@golang.org>
This commit is contained in:
Nigel Tao 2015-04-13 13:25:28 +10:00
parent 8b27d28ed4
commit 2f98bac310
2 changed files with 23 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
src/image/jpeg/reader.go
View File

@ -170,7 +170,7 @@ func (d *decoder) fill() error {
// can happen when expecting to read a 0xff 0x00 byte-stuffed byte.
func (d *decoder) unreadByteStuffedByte() {
if d.bytes.nUnreadable == 0 {
panic("jpeg: unreadByteStuffedByte call cannot be fulfilled")
return
}
d.bytes.i -= d.bytes.nUnreadable
d.bytes.nUnreadable = 0
@ -242,12 +242,7 @@ func (d *decoder) readByteStuffedByte() (x byte, err error) {
// stuffing.
func (d *decoder) readFull(p []byte) error {
// Unread the overshot bytes, if any.
if d.bytes.nUnreadable != 0 {
if d.bits.n >= 8 {
d.unreadByteStuffedByte()
}
d.bytes.nUnreadable = 0
}
d.unreadByteStuffedByte()
for {
n := copy(p, d.bytes.buf[d.bytes.i:d.bytes.j])
@ -269,12 +264,7 @@ func (d *decoder) readFull(p []byte) error {
// ignore ignores the next n bytes.
func (d *decoder) ignore(n int) error {
// Unread the overshot bytes, if any.
if d.bytes.nUnreadable != 0 {
if d.bits.n >= 8 {
d.unreadByteStuffedByte()
}
d.bytes.nUnreadable = 0
}
d.unreadByteStuffedByte()
for {
m := d.bytes.j - d.bytes.i

20
src/image/jpeg/reader_test.go
View File

@ -186,6 +186,26 @@ func pixString(pix []byte, stride, x, y int) string {
return s.String()
}
func TestTruncatedSOSDataDoesntPanic(t *testing.T) {
b, err := ioutil.ReadFile("../testdata/video-005.gray.q50.jpeg")
if err != nil {
t.Fatal(err)
}
sosMarker := []byte{0xff, 0xda}
i := bytes.Index(b, sosMarker)
if i < 0 {
t.Fatal("SOS marker not found")
}
i += len(sosMarker)
j := i + 10
if j > len(b) {
j = len(b)
}
for ; i < j; i++ {
Decode(bytes.NewReader(b[:i]))
}
}
func TestExtraneousData(t *testing.T) {
// Encode a 1x1 red image.
src := image.NewRGBA(image.Rect(0, 0, 1, 1))