    protected function edebug($str)
    {
        if ($this->SMTPDebug <= 0) {
            return;
        }
        //Avoid clash with built-in function names
        if (!in_array($this->Debugoutput, array('error_log', 'html', 'echo')) and is_callable($this->Debugoutput)) {
            call_user_func($this->Debugoutput, $str, $this->SMTPDebug);
            return;
        }
        switch ($this->Debugoutput) {
            case 'error_log':
                //Don't output, just log
                error_log($str);
                break;
            case 'html':
                //Cleans up output a bit for a better looking, HTML-safe output
                echo htmlentities(
                    preg_replace('/[\r\n]+/', '', $str),
                    ENT_QUOTES,
                    'UTF-8'
                )
                . "<br>\n";
                break;
            case 'echo':
            default:
                //Normalize line breaks
                $str = preg_replace('/(\r\n|\r|\n)/ms', "\n", $str);
                echo gmdate('Y-m-d H:i:s') . "\t" . str_replace(
                    "\n",
                    "\n                   \t                  ",
                    trim($str)
                ) . "\n";
        }
    }
The software 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.