Horde_Mime_Part::_transferDecode PHP Method

    protected function _transferDecode($fp, $encoding)
    {
        /* If the contents are empty, return now. */
        fseek($fp, 0, SEEK_END);
        if (ftell($fp)) {
            switch ($encoding) {
                case 'base64':
                    try {
                        return $this->_writeStream($fp, array('error' => true, 'filter' => array('convert.base64-decode' => array())));
                    } catch (ErrorException $e) {
                    }
                    rewind($fp);
                    return $this->_writeStream(base64_decode(stream_get_contents($fp)));
                case 'quoted-printable':
                    try {
                        return $this->_writeStream($fp, array('error' => true, 'filter' => array('convert.quoted-printable-decode' => array())));
                    } catch (ErrorException $e) {
                    }
                    // Workaround for Horde Bug #8747
                    rewind($fp);
                    return $this->_writeStream(quoted_printable_decode(stream_get_contents($fp)));
                case 'uuencode':
                case 'x-uuencode':
                case 'x-uue':
                    /* Support for uuencoded encoding - although not required by
                     * RFCs, some mailers may still encode this way. */
                    $res = Horde_Mime::uudecode($this->_readStream($fp));
                    return $this->_writeStream($res[0]['data']);
            }
        }
        return $fp;
    }