image/jpeg: return io.ErrUnexpectedEOF on truncated data

Decoder calls fill from readFull, ignore and readByte and
readByte did not check returned io.EOF.

This change moves io.EOF translation inside fill.

name                 old speed      new speed      delta
DecodeBaseline-8     67.4MB/s ± 0%  67.3MB/s ± 0%  -0.20%  (p=0.000 n=16+19)
DecodeProgressive-8  43.7MB/s ± 0%  43.6MB/s ± 0%  -0.06%  (p=0.013 n=17+19)

Fixes #56724

Change-Id: Ia0d5cc561f3c2050e25ec3f2b5e6866c3b4941c7
GitHub-Last-Rev: 470154373bc1452dffc5293d9a840e972749a76d
GitHub-Pull-Request: golang/go#56863
Reviewed-on: https://go-review.googlesource.com/c/go/+/452335
Run-TryBot: Rob Pike <r@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Reviewed-by: Nigel Tao (INACTIVE; USE @golang.org INSTEAD) <nigeltao@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/image/jpeg/huffman.go b/src/image/jpeg/huffman.go
index 95aaf71e2f36cc2f52887d6facb6b144f1246c15..72444369ab3e112d55bf678254a7305dab59ef12 100644 (file)
--- a/src/image/jpeg/huffman.go
+++ b/src/image/jpeg/huffman.go
@@ -49,7 +49,7 @@ func (d *decoder) ensureNBits(n int32) error {
        for {
                c, err := d.readByteStuffedByte()
                if err != nil {
-                       if err == io.EOF {
+                       if err == io.ErrUnexpectedEOF {
                                return errShortHuffmanData
                        }
                        return err

diff --git a/src/image/jpeg/reader.go b/src/image/jpeg/reader.go
index b34072396cbefaf464b7525f179315a1d142424b..61f2b4020d5d8de1f987df900fa56d837d30c292 100644 (file)
--- a/src/image/jpeg/reader.go
+++ b/src/image/jpeg/reader.go
@@ -164,7 +164,10 @@ func (d *decoder) fill() error {
        n, err := d.r.Read(d.bytes.buf[d.bytes.j:])
        d.bytes.j += n
        if n > 0 {
-               err = nil
+               return nil
+       }
+       if err == io.EOF {
+               err = io.ErrUnexpectedEOF
        }
        return err
 }
@@ -261,9 +264,6 @@ func (d *decoder) readFull(p []byte) error {
                        break
                }
                if err := d.fill(); err != nil {
-                       if err == io.EOF {
-                               err = io.ErrUnexpectedEOF
-                       }
                        return err
                }
        }
@@ -291,9 +291,6 @@ func (d *decoder) ignore(n int) error {
                        break
                }
                if err := d.fill(); err != nil {
-                       if err == io.EOF {
-                               err = io.ErrUnexpectedEOF
-                       }
                        return err
                }
        }

diff --git a/src/image/jpeg/reader_test.go b/src/image/jpeg/reader_test.go
index 02a2eb6509bc4772a441a721d357b29d732d3eb5..cdac2dd7563523b208a94856fc48fbb5cda0c653 100644 (file)
--- a/src/image/jpeg/reader_test.go
+++ b/src/image/jpeg/reader_test.go
@@ -490,6 +490,20 @@ func TestExtraneousData(t *testing.T) {
        }
 }
 
+func TestIssue56724(t *testing.T) {
+       b, err := os.ReadFile("../testdata/video-001.jpeg")
+       if err != nil {
+               t.Fatal(err)
+       }
+
+       b = b[:24] // truncate image data
+
+       _, err = Decode(bytes.NewReader(b))
+       if err != io.ErrUnexpectedEOF {
+               t.Errorf("got: %v, want: %v", err, io.ErrUnexpectedEOF)
+       }
+}
+
 func benchmarkDecode(b *testing.B, filename string) {
        data, err := os.ReadFile(filename)
        if err != nil {