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| author | Roland Shoemaker <roland@golang.org> | 2024-04-09 15:27:30 +0200 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2024-04-11 16:15:54 +0000 |
| commit | 48e00ab70a49652d4b015ac71b80da9f3ae7d1ab (patch) | |
| tree | 0817dafdef6255ea682b7ae40335dc89de5cdc54 /src/image | |
| parent | b6778c5230d554c1ba1a69b104513021467d32b2 (diff) | |
| download | go-48e00ab70a49652d4b015ac71b80da9f3ae7d1ab.tar.xz | |
image/gif: revert incorrect usage of clear
CL 570555 replaced a loop which added empty
color.RGBA elements with a call to clear.
color.Palette is a slice of interfaces, so using
clear results in a slice of nil elements, rather
than what we previously had which was empty
color.RGBA elements. This could cause a panic when
attempting to re-encode a GIF which had an
extended color palette because of the weird
transparency hack.
This was discovered by OSS-Fuzz. I've added a test
case using their reproducer in order to prevent
future regressions.
Change-Id: I00a89257d90b6cca68672173eecdaa0a24f18d9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/577555
Reviewed-by: Nigel Tao <nigeltao@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Roland Shoemaker <roland@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Diffstat (limited to 'src/image')
| -rw-r--r-- | src/image/gif/reader.go | 6 | ||||
| -rw-r--r-- | src/image/gif/reader_test.go | 16 |
2 files changed, 20 insertions, 2 deletions
diff --git a/src/image/gif/reader.go b/src/image/gif/reader.go index 8d6faf87a3..b4ea4fdea1 100644 --- a/src/image/gif/reader.go +++ b/src/image/gif/reader.go @@ -406,8 +406,10 @@ func (d *decoder) readImageDescriptor(keepAllFrames bool) error { // seem OK with this, so we enlarge the palette with // transparent colors. See golang.org/issue/15059. p := make(color.Palette, ti+1) - i := copy(p, m.Palette) - clear(p[i:]) + copy(p, m.Palette) + for i := len(m.Palette); i < len(p); i++ { + p[i] = color.RGBA{} + } m.Palette = p } } diff --git a/src/image/gif/reader_test.go b/src/image/gif/reader_test.go index f90ebc5d7d..92313c92ce 100644 --- a/src/image/gif/reader_test.go +++ b/src/image/gif/reader_test.go @@ -7,6 +7,7 @@ package gif import ( "bytes" "compress/lzw" + "encoding/hex" "image" "image/color" "image/color/palette" @@ -439,3 +440,18 @@ func BenchmarkDecode(b *testing.B) { Decode(bytes.NewReader(data)) } } + +func TestReencodeExtendedPalette(t *testing.T) { + data, err := hex.DecodeString("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") + if err != nil { + t.Fatal(err) + } + img, err := Decode(bytes.NewReader(data)) + if err != nil { + t.Fatal(err) + } + err = Encode(io.Discard, img, &Options{NumColors: 1}) + if err != nil { + t.Fatal(err) + } +} |