Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 441 insertions, 0 deletions

diff --git a/src/image/gif/reader_test.go b/src/image/gif/reader_test.go
new file mode 100644
index 0000000..a7f943a
--- /dev/null
+++ b/src/image/gif/reader_test.go
@@ -0,0 +1,441 @@
+// Copyright 2013 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 gif
+
+import (
+	"bytes"
+	"compress/lzw"
+	"image"
+	"image/color"
+	"image/color/palette"
+	"io"
+	"os"
+	"reflect"
+	"runtime"
+	"runtime/debug"
+	"strings"
+	"testing"
+)
+
+// header, palette and trailer are parts of a valid 2x1 GIF image.
+const (
+	headerStr = "GIF89a" +
+		"\x02\x00\x01\x00" + // width=2, height=1
+		"\x80\x00\x00" // headerFields=(a color table of 2 pixels), backgroundIndex, aspect
+	paletteStr = "\x10\x20\x30\x40\x50\x60" // the color table, also known as a palette
+	trailerStr = "\x3b"
+)
+
+// lzw.NewReader wants a io.ByteReader, this ensures we're compatible.
+var _ io.ByteReader = (*blockReader)(nil)
+
+// lzwEncode returns an LZW encoding (with 2-bit literals) of in.
+func lzwEncode(in []byte) []byte {
+	b := &bytes.Buffer{}
+	w := lzw.NewWriter(b, lzw.LSB, 2)
+	if _, err := w.Write(in); err != nil {
+		panic(err)
+	}
+	if err := w.Close(); err != nil {
+		panic(err)
+	}
+	return b.Bytes()
+}
+
+func TestDecode(t *testing.T) {
+	// extra contains superfluous bytes to inject into the GIF, either at the end
+	// of an existing data sub-block (past the LZW End of Information code) or in
+	// a separate data sub-block. The 0x02 values are arbitrary.
+	const extra = "\x02\x02\x02\x02"
+
+	testCases := []struct {
+		nPix int // The number of pixels in the image data.
+		// If non-zero, write this many extra bytes inside the data sub-block
+		// containing the LZW end code.
+		extraExisting int
+		// If non-zero, write an extra block of this many bytes.
+		extraSeparate int
+		wantErr       error
+	}{
+		{0, 0, 0, errNotEnough},
+		{1, 0, 0, errNotEnough},
+		{2, 0, 0, nil},
+		// An extra data sub-block after the compressed section with 1 byte which we
+		// silently skip.
+		{2, 0, 1, nil},
+		// An extra data sub-block after the compressed section with 2 bytes. In
+		// this case we complain that there is too much data.
+		{2, 0, 2, errTooMuch},
+		// Too much pixel data.
+		{3, 0, 0, errTooMuch},
+		// An extra byte after LZW data, but inside the same data sub-block.
+		{2, 1, 0, nil},
+		// Two extra bytes after LZW data, but inside the same data sub-block.
+		{2, 2, 0, nil},
+		// Extra data exists in the final sub-block with LZW data, AND there is
+		// a bogus sub-block following.
+		{2, 1, 1, errTooMuch},
+	}
+	for _, tc := range testCases {
+		b := &bytes.Buffer{}
+		b.WriteString(headerStr)
+		b.WriteString(paletteStr)
+		// Write an image with bounds 2x1 but tc.nPix pixels. If tc.nPix != 2
+		// then this should result in an invalid GIF image. First, write a
+		// magic 0x2c (image descriptor) byte, bounds=(0,0)-(2,1), a flags
+		// byte, and 2-bit LZW literals.
+		b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02")
+		if tc.nPix > 0 {
+			enc := lzwEncode(make([]byte, tc.nPix))
+			if len(enc)+tc.extraExisting > 0xff {
+				t.Errorf("nPix=%d, extraExisting=%d, extraSeparate=%d: compressed length %d is too large",
+					tc.nPix, tc.extraExisting, tc.extraSeparate, len(enc))
+				continue
+			}
+
+			// Write the size of the data sub-block containing the LZW data.
+			b.WriteByte(byte(len(enc) + tc.extraExisting))
+
+			// Write the LZW data.
+			b.Write(enc)
+
+			// Write extra bytes inside the same data sub-block where LZW data
+			// ended. Each arbitrarily 0x02.
+			b.WriteString(extra[:tc.extraExisting])
+		}
+
+		if tc.extraSeparate > 0 {
+			// Data sub-block size. This indicates how many extra bytes follow.
+			b.WriteByte(byte(tc.extraSeparate))
+			b.WriteString(extra[:tc.extraSeparate])
+		}
+		b.WriteByte(0x00) // An empty block signifies the end of the image data.
+		b.WriteString(trailerStr)
+
+		got, err := Decode(b)
+		if err != tc.wantErr {
+			t.Errorf("nPix=%d, extraExisting=%d, extraSeparate=%d\ngot  %v\nwant %v",
+				tc.nPix, tc.extraExisting, tc.extraSeparate, err, tc.wantErr)
+		}
+
+		if tc.wantErr != nil {
+			continue
+		}
+		want := &image.Paletted{
+			Pix:    []uint8{0, 0},
+			Stride: 2,
+			Rect:   image.Rect(0, 0, 2, 1),
+			Palette: color.Palette{
+				color.RGBA{0x10, 0x20, 0x30, 0xff},
+				color.RGBA{0x40, 0x50, 0x60, 0xff},
+			},
+		}
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("nPix=%d, extraExisting=%d, extraSeparate=%d\ngot  %v\nwant %v",
+				tc.nPix, tc.extraExisting, tc.extraSeparate, got, want)
+		}
+	}
+}
+
+func TestTransparentIndex(t *testing.T) {
+	b := &bytes.Buffer{}
+	b.WriteString(headerStr)
+	b.WriteString(paletteStr)
+	for transparentIndex := 0; transparentIndex < 3; transparentIndex++ {
+		if transparentIndex < 2 {
+			// Write the graphic control for the transparent index.
+			b.WriteString("\x21\xf9\x04\x01\x00\x00")
+			b.WriteByte(byte(transparentIndex))
+			b.WriteByte(0)
+		}
+		// Write an image with bounds 2x1, as per TestDecode.
+		b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02")
+		enc := lzwEncode([]byte{0x00, 0x00})
+		if len(enc) > 0xff {
+			t.Fatalf("compressed length %d is too large", len(enc))
+		}
+		b.WriteByte(byte(len(enc)))
+		b.Write(enc)
+		b.WriteByte(0x00)
+	}
+	b.WriteString(trailerStr)
+
+	g, err := DecodeAll(b)
+	if err != nil {
+		t.Fatalf("DecodeAll: %v", err)
+	}
+	c0 := color.RGBA{paletteStr[0], paletteStr[1], paletteStr[2], 0xff}
+	c1 := color.RGBA{paletteStr[3], paletteStr[4], paletteStr[5], 0xff}
+	cz := color.RGBA{}
+	wants := []color.Palette{
+		{cz, c1},
+		{c0, cz},
+		{c0, c1},
+	}
+	if len(g.Image) != len(wants) {
+		t.Fatalf("got %d images, want %d", len(g.Image), len(wants))
+	}
+	for i, want := range wants {
+		got := g.Image[i].Palette
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("palette #%d:\ngot  %v\nwant %v", i, got, want)
+		}
+	}
+}
+
+// testGIF is a simple GIF that we can modify to test different scenarios.
+var testGIF = []byte{
+	'G', 'I', 'F', '8', '9', 'a',
+	1, 0, 1, 0, // w=1, h=1 (6)
+	128, 0, 0, // headerFields, bg, aspect (10)
+	0, 0, 0, 1, 1, 1, // color table and graphics control (13)
+	0x21, 0xf9, 0x04, 0x00, 0x00, 0x00, 0xff, 0x00, // (19)
+	// frame 1 (0,0 - 1,1)
+	0x2c,
+	0x00, 0x00, 0x00, 0x00,
+	0x01, 0x00, 0x01, 0x00, // (32)
+	0x00,
+	0x02, 0x02, 0x4c, 0x01, 0x00, // lzw pixels
+	// trailer
+	0x3b,
+}
+
+func try(t *testing.T, b []byte, want string) {
+	_, err := DecodeAll(bytes.NewReader(b))
+	var got string
+	if err != nil {
+		got = err.Error()
+	}
+	if got != want {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestBounds(t *testing.T) {
+	// Make a local copy of testGIF.
+	gif := make([]byte, len(testGIF))
+	copy(gif, testGIF)
+	// Make the bounds too big, just by one.
+	gif[32] = 2
+	want := "gif: frame bounds larger than image bounds"
+	try(t, gif, want)
+
+	// Make the bounds too small; does not trigger bounds
+	// check, but now there's too much data.
+	gif[32] = 0
+	want = "gif: too much image data"
+	try(t, gif, want)
+	gif[32] = 1
+
+	// Make the bounds really big, expect an error.
+	want = "gif: frame bounds larger than image bounds"
+	for i := 0; i < 4; i++ {
+		gif[32+i] = 0xff
+	}
+	try(t, gif, want)
+}
+
+func TestNoPalette(t *testing.T) {
+	b := &bytes.Buffer{}
+
+	// Manufacture a GIF with no palette, so any pixel at all
+	// will be invalid.
+	b.WriteString(headerStr[:len(headerStr)-3])
+	b.WriteString("\x00\x00\x00") // No global palette.
+
+	// Image descriptor: 2x1, no local palette, and 2-bit LZW literals.
+	b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02")
+
+	// Encode the pixels: neither is in range, because there is no palette.
+	enc := lzwEncode([]byte{0x00, 0x03})
+	b.WriteByte(byte(len(enc)))
+	b.Write(enc)
+	b.WriteByte(0x00) // An empty block signifies the end of the image data.
+
+	b.WriteString(trailerStr)
+
+	try(t, b.Bytes(), "gif: no color table")
+}
+
+func TestPixelOutsidePaletteRange(t *testing.T) {
+	for _, pval := range []byte{0, 1, 2, 3} {
+		b := &bytes.Buffer{}
+
+		// Manufacture a GIF with a 2 color palette.
+		b.WriteString(headerStr)
+		b.WriteString(paletteStr)
+
+		// Image descriptor: 2x1, no local palette, and 2-bit LZW literals.
+		b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02")
+
+		// Encode the pixels; some pvals trigger the expected error.
+		enc := lzwEncode([]byte{pval, pval})
+		b.WriteByte(byte(len(enc)))
+		b.Write(enc)
+		b.WriteByte(0x00) // An empty block signifies the end of the image data.
+
+		b.WriteString(trailerStr)
+
+		// No error expected, unless the pixels are beyond the 2 color palette.
+		want := ""
+		if pval >= 2 {
+			want = "gif: invalid pixel value"
+		}
+		try(t, b.Bytes(), want)
+	}
+}
+
+func TestTransparentPixelOutsidePaletteRange(t *testing.T) {
+	b := &bytes.Buffer{}
+
+	// Manufacture a GIF with a 2 color palette.
+	b.WriteString(headerStr)
+	b.WriteString(paletteStr)
+
+	// Graphic Control Extension: transparency, transparent color index = 3.
+	//
+	// This index, 3, is out of range of the global palette and there is no
+	// local palette in the subsequent image descriptor. This is an error
+	// according to the spec, but Firefox and Google Chrome seem OK with this.
+	//
+	// See golang.org/issue/15059.
+	b.WriteString("\x21\xf9\x04\x01\x00\x00\x03\x00")
+
+	// Image descriptor: 2x1, no local palette, and 2-bit LZW literals.
+	b.WriteString("\x2c\x00\x00\x00\x00\x02\x00\x01\x00\x00\x02")
+
+	// Encode the pixels.
+	enc := lzwEncode([]byte{0x03, 0x03})
+	b.WriteByte(byte(len(enc)))
+	b.Write(enc)
+	b.WriteByte(0x00) // An empty block signifies the end of the image data.
+
+	b.WriteString(trailerStr)
+
+	try(t, b.Bytes(), "")
+}
+
+func TestLoopCount(t *testing.T) {
+	testCases := []struct {
+		name      string
+		data      []byte
+		loopCount int
+	}{
+		{
+			"loopcount-missing",
+			[]byte("GIF89a000\x00000" +
+				",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 0 descriptor & color table
+				"\x02\b\xf01u\xb9\xfdal\x05\x00;"), // image 0 image data & trailer
+			-1,
+		},
+		{
+			"loopcount-0",
+			[]byte("GIF89a000\x00000" +
+				"!\xff\vNETSCAPE2.0\x03\x01\x00\x00\x00" + // loop count = 0
+				",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 0 descriptor & color table
+				"\x02\b\xf01u\xb9\xfdal\x05\x00" + // image 0 image data
+				",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 1 descriptor & color table
+				"\x02\b\xf01u\xb9\xfdal\x05\x00;"), // image 1 image data & trailer
+			0,
+		},
+		{
+			"loopcount-1",
+			[]byte("GIF89a000\x00000" +
+				"!\xff\vNETSCAPE2.0\x03\x01\x01\x00\x00" + // loop count = 1
+				",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 0 descriptor & color table
+				"\x02\b\xf01u\xb9\xfdal\x05\x00" + // image 0 image data
+				",0\x00\x00\x00\n\x00\n\x00\x80000000" + // image 1 descriptor & color table
+				"\x02\b\xf01u\xb9\xfdal\x05\x00;"), // image 1 image data & trailer
+			1,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			img, err := DecodeAll(bytes.NewReader(tc.data))
+			if err != nil {
+				t.Fatal("DecodeAll:", err)
+			}
+			w := new(bytes.Buffer)
+			err = EncodeAll(w, img)
+			if err != nil {
+				t.Fatal("EncodeAll:", err)
+			}
+			img1, err := DecodeAll(w)
+			if err != nil {
+				t.Fatal("DecodeAll:", err)
+			}
+			if img.LoopCount != tc.loopCount {
+				t.Errorf("loop count mismatch: %d vs %d", img.LoopCount, tc.loopCount)
+			}
+			if img.LoopCount != img1.LoopCount {
+				t.Errorf("loop count failed round-trip: %d vs %d", img.LoopCount, img1.LoopCount)
+			}
+		})
+	}
+}
+
+func TestUnexpectedEOF(t *testing.T) {
+	for i := len(testGIF) - 1; i >= 0; i-- {
+		_, err := DecodeAll(bytes.NewReader(testGIF[:i]))
+		if err == errNotEnough {
+			continue
+		}
+		text := ""
+		if err != nil {
+			text = err.Error()
+		}
+		if !strings.HasPrefix(text, "gif:") || !strings.HasSuffix(text, ": unexpected EOF") {
+			t.Errorf("Decode(testGIF[:%d]) = %v, want gif: ...: unexpected EOF", i, err)
+		}
+	}
+}
+
+// See golang.org/issue/22237
+func TestDecodeMemoryConsumption(t *testing.T) {
+	const frames = 3000
+	img := image.NewPaletted(image.Rectangle{Max: image.Point{1, 1}}, palette.WebSafe)
+	hugeGIF := &GIF{
+		Image:    make([]*image.Paletted, frames),
+		Delay:    make([]int, frames),
+		Disposal: make([]byte, frames),
+	}
+	for i := 0; i < frames; i++ {
+		hugeGIF.Image[i] = img
+		hugeGIF.Delay[i] = 60
+	}
+	buf := new(bytes.Buffer)
+	if err := EncodeAll(buf, hugeGIF); err != nil {
+		t.Fatal("EncodeAll:", err)
+	}
+	s0, s1 := new(runtime.MemStats), new(runtime.MemStats)
+	runtime.GC()
+	defer debug.SetGCPercent(debug.SetGCPercent(5))
+	runtime.ReadMemStats(s0)
+	if _, err := Decode(buf); err != nil {
+		t.Fatal("Decode:", err)
+	}
+	runtime.ReadMemStats(s1)
+	if heapDiff := int64(s1.HeapAlloc - s0.HeapAlloc); heapDiff > 30<<20 {
+		t.Fatalf("Decode of %d frames increased heap by %dMB", frames, heapDiff>>20)
+	}
+}
+
+func BenchmarkDecode(b *testing.B) {
+	data, err := os.ReadFile("../testdata/video-001.gif")
+	if err != nil {
+		b.Fatal(err)
+	}
+	cfg, err := DecodeConfig(bytes.NewReader(data))
+	if err != nil {
+		b.Fatal(err)
+	}
+	b.SetBytes(int64(cfg.Width * cfg.Height))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Decode(bytes.NewReader(data))
+	}
+}