/**
* Decode a mime-encoded string to internal charset
*
* @param string $input Header value
* @param string $fallback Fallback charset if none specified
*
* @return string Decoded string
* @static
*/
public static function decode_mime_string($input, $fallback = null)
{
// Initialize variable
$out = '';
// Iterate instead of recursing, this way if there are too many values we don't have stack overflows
// rfc: all line breaks or other characters not found
// in the Base64 Alphabet must be ignored by decoding software
// delete all blanks between MIME-lines, differently we can
// receive unnecessary blanks and broken utf-8 symbols
$input = preg_replace("/\\?=\\s+=\\?/", '?==?', $input);
// Check if there is stuff to decode
if (strpos($input, '=?') !== false) {
// Loop through the string to decode all occurences of =? ?= into the variable $out
while (($pos = strpos($input, '=?')) !== false) {
// Append everything that is before the text to be decoded
$out .= substr($input, 0, $pos);
// Get the location of the text to decode
$end_cs_pos = strpos($input, "?", $pos + 2);
$end_en_pos = strpos($input, "?", $end_cs_pos + 1);
$end_pos = strpos($input, "?=", $end_en_pos + 1);
// Extract the encoded string
$encstr = substr($input, $pos + 2, $end_pos - $pos - 2);
// Extract the remaining string
$input = substr($input, $end_pos + 2);
// Decode the string fragement
$out .= rcube_imap::_decode_mime_string_part($encstr);
}
// Deocde the rest (if any)
if (strlen($input) != 0) {
$out .= rcube_imap::decode_mime_string($input, $fallback);
}
// return the results
return $out;
}
// no encoding information, use fallback
return rcube_charset_convert($input, !empty($fallback) ? $fallback : rcmail::get_instance()->config->get('default_charset', 'ISO-8859-1'));
}
