// descriptors and should account for either case when reading
	// ZIP files to ensure compatibility."
	//
	// dataDescriptorLen includes the size of the signature but
	// first read just those 4 bytes to see if it exists.
	if _, err := io.ReadFull(r, buf[:4]); err != nil {
		return err
	}
	off := 0
	maybeSig := readBuf(buf[:4])
	if maybeSig.uint32() != dataDescriptorSignature {
		// No data descriptor signature. Keep these four

			for _, c := range blk {
				if c == '\n' {
					cntNewline++
				}
			}
		}
		return nil
	}

	// nextToken gets the next token delimited by a newline. This assumes that
	// at least one newline exists in the buffer.
	nextToken := func() string {
		cntNewline--
		tok, _ := buf.ReadString('\n')
		return strings.TrimRight(tok, "\n")
	}

	// Parse for the number of entries.