7z: Fix iteration bug

[SheltonZhu]

7z: Fix iteration bug that was already fixed in go 1.22.
The bug is same as https://github.com/mholt/archiver/blob/master/zip.go#L199

[mholt]

Thanks! Go 1.22 hasn't been released yet, and I doubt everyone will upgrade right away. I'll probably hold this open for a while until the release has been out for a while.

[SheltonZhu]

Thanks! Go 1.22 hasn't been released yet, and I doubt everyone will upgrade right away. I'll probably hold this open for a while until the release has been out for a while.

I mean I fix the "for" loops bug (sharing of loop variables).
Please merge my pr.
And the issue is same as zip.go, The funtion archiver.File.Open() is a closure.
I copy code from https://github.com/mholt/archiver/blob/master/zip.go#L199

ref: go-reference-in-for-loop-sets-the-wrong-reference

[SheltonZhu]

And go 1.22 has fix it. (No more sharing of loop variables)
ref: https://antonz.org/go-1-22/

[SheltonZhu]

I can't get the excepted io.ReadCloser when I call archiver.File.Open() outside of the archiver.FileHandler.
But it is correct when I use archiver.Zip{}. (Translated from GPT)

type ArchiverExtractor struct {
	archiver.Extractor
	sourceArchive   io.Reader
	fileHandlerFunc FileHanderFunc
	pathsInArchive  []string
}

func (ae *ArchiverExtractor) ExtractFile(ctx context.Context, filePath string) (*archiver.File, error) {
	files := make([]archiver.File, 0)
	ff := FileFilter(&files, filePath)
	if ae.fileHandlerFunc != nil {
		ff = ae.fileHandlerFunc(&files)
	}
	err := ae.Extract(ctx, ae.sourceArchive, ae.pathsInArchive, ff)
	if len(files) == 0 {
		return nil, fmt.Errorf("file not found")
	}
	return &files[0], err
}

// ...
func main() {
    // ...

    frc, err := f.Open() 
    if err != nil {
       panic(err)
    }
    defer frc.Close()
    fileBytes, _ := io.ReadAll(frc) // empty 
}

[mholt]

Oh, my bad -- I understand now. Thank you.