codePoint == 0x7f ||
      codePoint >= 0x80 && !unicodeAllowed ||
      codePoint.toChar() in encodeSet ||
      codePoint == '%'.code &&
      (!alreadyEncoded || strict && !input.isPercentEncoded(i, limit))
    ) {
      // Percent encode this character.
      if (encodedCharBuffer == null) {
        encodedCharBuffer = Buffer()
      }

      if (charset == null || charset == Charsets.UTF_8) {