Language: PHP
Label: safe
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
    public function compareTo($l)
    {
        if ($l === false) {
            return false;
        }
        if ($l->unit !== $this->unit) {
            $converter = new HTMLPurifier_UnitConverter();
            $l = $converter->convert($l, $this->unit);
            if ($l === false) {
                return false;
            }
        }
        return $this->n - $l->n;
    }