libgo: update to Go 1.13beta1 release

    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/193497

From-SVN: r275473

5 files changed, 68 insertions, 2 deletions

diff --git a/libgo/go/image/png/fuzz.go b/libgo/go/image/png/fuzz.go
new file mode 100644
index 0000000..d9cb392
--- /dev/null
+++ b/libgo/go/image/png/fuzz.go
@@ -0,0 +1,52 @@
+// Copyright 2019 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.
+
+// +build gofuzz
+
+package png
+
+import (
+	"bytes"
+	"fmt"
+)
+
+func Fuzz(data []byte) int {
+	cfg, err := DecodeConfig(bytes.NewReader(data))
+	if err != nil {
+		return 0
+	}
+	if cfg.Width*cfg.Height > 1e6 {
+		return 0
+	}
+	img, err := Decode(bytes.NewReader(data))
+	if err != nil {
+		return 0
+	}
+	levels := []CompressionLevel{
+		DefaultCompression,
+		NoCompression,
+		BestSpeed,
+		BestCompression,
+	}
+	for _, l := range levels {
+		var w bytes.Buffer
+		e := &Encoder{CompressionLevel: l}
+		err = e.Encode(&w, img)
+		if err != nil {
+			panic(err)
+		}
+		img1, err := Decode(&w)
+		if err != nil {
+			panic(err)
+		}
+		got := img1.Bounds()
+		want := img.Bounds()
+		if !got.Eq(want) {
+			fmt.Printf("bounds0: %#v\n", want)
+			fmt.Printf("bounds1: %#v\n", got)
+			panic("bounds have changed")
+		}
+	}
+	return 1
+}
diff --git a/libgo/go/image/png/reader.go b/libgo/go/image/png/reader.go
index 53fbf3e..6771973 100644
--- a/libgo/go/image/png/reader.go
+++ b/libgo/go/image/png/reader.go
@@ -706,7 +706,7 @@ func (d *decoder) readImagePass(r io.Reader, pass int, allocateOnly bool) (image
 				}
 			}
 		case cbP8:
-			if len(paletted.Palette) != 255 {
+			if len(paletted.Palette) != 256 {
 				for x := 0; x < width; x++ {
 					if len(paletted.Palette) <= int(cdat[x]) {
 						paletted.Palette = paletted.Palette[:int(cdat[x])+1]
diff --git a/libgo/go/image/png/reader_test.go b/libgo/go/image/png/reader_test.go
index 33dcd3d..3325d2e 100644
--- a/libgo/go/image/png/reader_test.go
+++ b/libgo/go/image/png/reader_test.go
@@ -584,6 +584,21 @@ func TestUnknownChunkLengthUnderflow(t *testing.T) {
 	}
 }
 
+func TestPaletted8OutOfRangePixel(t *testing.T) {
+	// IDAT contains a reference to a palette index that does not exist in the file.
+	img, err := readPNG("testdata/invalid-palette.png")
+	if err != nil {
+		t.Errorf("decoding invalid-palette.png: unexpected error %v", err)
+		return
+	}
+
+	// Expect that the palette is extended with opaque black.
+	want := color.RGBA{0x00, 0x00, 0x00, 0xff}
+	if got := img.At(15, 15); got != want {
+		t.Errorf("got %F %v, expected %T %v", got, got, want, want)
+	}
+}
+
 func TestGray8Transparent(t *testing.T) {
 	// These bytes come from https://golang.org/issues/19553
 	m, err := Decode(bytes.NewReader([]byte{
diff --git a/libgo/go/image/png/testdata/invalid-palette.png b/libgo/go/image/png/testdata/invalid-palette.png
new file mode 100644
index 0000000..a747e59
--- /dev/null
+++ b/libgo/go/image/png/testdata/invalid-palette.png
diff --git a/libgo/go/image/png/writer.go b/libgo/go/image/png/writer.go
index c033351..2bd4fde 100644
--- a/libgo/go/image/png/writer.go
+++ b/libgo/go/image/png/writer.go
@@ -288,7 +288,6 @@ func filter(cr *[nFilter][]byte, pr []byte, bpp int) int {
 		}
 	}
 	if sum < best {
-		best = sum
 		filter = ftAverage
 	}