Lexer.php:163 を以下のように修正します
if (isset($this->positions[2][$this->position][0]) ) {
$text = rtrim($text);
}
↓
if (isset($this->positions[2][$this->position][0]) && ($this->options['whitespace_trim'] === $this->positions[2][$this->position][0])) {
$text = rtrim($text);
}