image/gif: Disposal is corrupted after round trip (original) (raw)

The following program:

package main

import ( "bytes" "fmt" "image/gif" )

func main() { data := []byte("GIF87au\x010\x00\xe800000000!" + "\xf9000000,0\x000\x000\x00\x00\x000\x02\b\r" + "0000000\x00!\xf90\x00\x00\x0000,0\x000" + "\x000\x00\x00\x000\x02\b\r0000000\x00;") img, err := gif.DecodeAll(bytes.NewReader(data)) if err != nil { return } w := new(bytes.Buffer) err = gif.EncodeAll(w, img) if err != nil { panic(err) } img1, err := gif.DecodeAll(w) if err != nil { panic(err) } fmt.Printf("LoopCount: %v -> %v\n", img.Disposal, img1.Disposal) }

prints:

LoopCount: [4 0] -> [4 4]

Disposal must be preserved after Encode/Decode.

go version devel +514014c Thu Jun 18 15:54:35 2015 +0200 linux/amd64