optimize

src/archive/tar/reader.go

@@ -380,6 +380,9 @@ func (tr *Reader) readHeader() (*Header, *block, error) {
 	v7 := tr.blk.toV7()
 	hdr.Typeflag = v7.typeFlag()[0]
 	hdr.Name = p.parseString(v7.name())
+	if hdr.FileInfo().IsDir() && !strings.HasSuffix(hdr.Name, "/") {
+		hdr.Name += "/"
+	}
 	hdr.Linkname = p.parseString(v7.linkName())
 	hdr.Size = p.parseNumeric(v7.size())
 	hdr.Mode = p.parseNumeric(v7.mode())

src/archive/tar/writer.go

@@ -424,9 +424,6 @@ func (tw *Writer) AddFS(fsys fs.FS) error {
 			return err
 		}
 		h.Name = name
-		if d.IsDir() {
-			h.Name += "/"
-		}
 		if err := tw.WriteHeader(h); err != nil {
 			return err
 		}

src/archive/zip/reader.go

@@ -384,6 +384,10 @@ func readDirectoryHeader(f *File, r io.Reader) error {
 		return err
 	}
 	f.Name = string(d[:filenameLen])
+	if f.FileInfo().IsDir() && !strings.HasSuffix(f.Name, "/") {
+		f.Name += "/"
+	}
+
 	f.Extra = d[filenameLen : filenameLen+extraLen]
 	f.Comment = string(d[filenameLen+extraLen:])
 

src/archive/zip/writer.go

@@ -520,9 +520,6 @@ func (w *Writer) AddFS(fsys fs.FS) error {
 			return err
 		}
 		h.Name = name
-		if d.IsDir() {
-			h.Name += "/"
-		}
 		h.Method = Deflate
 		fw, err := w.CreateHeader(h)
 		if err != nil {