Merge pull request #39 from hashicorp/fix-empty-archive-entries

Fixed a bug when archives contain entries without a name

slug.go

@@ -374,8 +374,14 @@ func (p *Packer) Unpack(r io.Reader, dst string) error {
 			return fmt.Errorf("failed to untar slug: %w", err)
 		}
 
-		// Get rid of absolute paths.
 		path := header.Name
+
+		// If the entry has no name, ignore it.
+		if path == "" {
+			continue
+		}
+
+		// Get rid of absolute paths.
 		if path[0] == '/' {
 			path = path[1:]
 		}

slug_test.go

@@ -1017,6 +1017,37 @@ func TestNewPacker(t *testing.T) {
 	}
 }
 
+func TestUnpackEmptyName(t *testing.T) {
+	var buf bytes.Buffer
+
+	gw := gzip.NewWriter(&buf)
+
+	tw := tar.NewWriter(gw)
+
+	tw.WriteHeader(&tar.Header{
+		Typeflag: tar.TypeDir,
+	})
+
+	tw.Close()
+	gw.Close()
+
+	if buf.Len() == 0 {
+		t.Fatal("unable to create tar properly")
+	}
+
+	dir, err := ioutil.TempDir("", "slug")
+	if err != nil {
+		t.Fatalf("err:%v", err)
+	}
+	defer os.RemoveAll(dir)
+
+	// This crashes unless the bug is fixed
+	err = Unpack(&buf, dir)
+	if err != nil {
+		t.Fatalf("err:%v", err)
+	}
+}
+
 // This is a reusable assertion for when packing testdata/archive-dir
 func assertArchiveFixture(t *testing.T, slug *bytes.Buffer, got *Meta) {
 	gzipR, err := gzip.NewReader(slug)