`archiver.Identify` fails on non-archive file: zlib: invalid header

What version of the package or command are you using?

The latest release of v4, v4.0.0-alpha.8

What are you trying to do?

Recursively extract a .tar.gz file.

What steps did you take?

Download https://github.com/kubernetes/git-sync/blob/b161f3f0c78b56f27188b4e4aabf672ba0b03706/vendor/github.com/google/licenseclassifier/licenses/licenses.db

Run the following reproducer


import (
    "context"
    "errors"
    "fmt"
    "os"
    "testing"

    "github.com/mholt/archiver/v4"
)

func TestTarGz(t *testing.T) {
    f, err := os.Open("/tmp/licenses.db")
    if err != nil {
        t.Fatal(err)
    }
    defer f.Close()

    format := archiver.CompressedArchive{
        Compression: archiver.Gz{},
        Archival:    archiver.Tar{},
    }
    err = format.Extract(context.Background(), f, nil, handler(t))
    if err != nil {
        t.Fatal(err)
    }
}

func handler(t *testing.T) func(ctx context.Context, file archiver.File) error {
    return func(ctx context.Context, file archiver.File) error {
        f, err := file.Open()
        if err != nil {
            t.Fatal(err)
        }
        defer f.Close()

        format, _, err := archiver.Identify(file.Name(), f)
        if err == nil {
            fmt.Printf("File '%s' is format '%s'\n", file.Name(), format.Name())
        } else if errors.Is(err, archiver.ErrNoMatch) {
            //fmt.Printf("File '%s' is not an archive\n", file.Name())
        } else {
            t.Errorf("Error identifying '%s' format: %v\n", file.Name(), err)
        }

        return nil
    }
}

What did you expect to happen, and what actually happened instead?

I expected that archiver.Identify would return archiver.ErrNoMatch as the file isn't an archive. However, a different error is returned.

Error identifying 'X11.txt' format: matching zip: zlib: invalid header

How do you think this should be fixed?

I'm not sure, it depends on the cause

Please link to any related issues, pull requests, and/or discussion

https://github.com/trufflesecurity/trufflehog/issues/2928

Bonus: What do you use archiver for, and do you find it useful?

I use archiver via TruffleHog. It is quite useful in that regard. :)

mholt / archiver

`archiver.Identify` fails on non-archive file: zlib: invalid header #406