Wrong domain encoding set by _get_codeset() if using direct calls to domain based methods

Problem:
after initial setup, a direct call to _dgettext (or to the others domain based methods) results in data being encoded with default ini_get('mbstring.internal_encoding') instead of that set for the domain with the bind_textdomain_codeset

Ex:
$domain = 'MyGettextPoMoFileName';
_bindtextdomain($domain,"i18n"); // "i18n" is the gettext data directory name
_bind_textdomain_codeset($domain,"UTF-8");
_setlocale(LC_MESSAGES, "it_IT));

echo _dgettext($domain,"message-accented-letters-àòèé");

result in: message-accented-letters-����

The problem is that the the parameter $domain is never passed to _get_codeset() function from the call inside the _encode() function called from _dgettext() (and all others d functions).
Actual code extract (v1.0.12):

function _get_codeset($domain=null) {
    global $text_domains, $default_domain, $LC_CATEGORIES;
    if (!isset($domain)) $domain = $default_domain;
    return (isset($text_domains[$domain]->codeset))? $text_domains[$domain]->codeset : ini_get('mbstring.internal_encoding');
}

function _encode($text) {
  $target_encoding = _get_codeset();
  if (function_exists("mb_detect_encoding")) {
    $source_encoding = mb_detect_encoding($text);
    if ($source_encoding != $target_encoding)
      $text = mb_convert_encoding($text, $target_encoding, $source_encoding);
  }
  return $text;
}

function _dngettext($domain, $singular, $plural, $number) {
    $l10n = _get_reader($domain);
    return _encode($l10n->ngettext($singular, $plural, $number));
}

Fix:

function _get_codeset($domain=null) {
    global $text_domains, $default_domain, $LC_CATEGORIES;
    if (!isset($domain)) $domain = $default_domain;
    return (isset($text_domains[$domain]->codeset))? $text_domains[$domain]->codeset : ini_get('mbstring.internal_encoding');
}

function _encode($text,$domain=null) {
  $target_encoding = _get_codeset($domain);
  if (function_exists("mb_detect_encoding")) {
    $source_encoding = mb_detect_encoding($text);
    if ($source_encoding != $target_encoding)
      $text = mb_convert_encoding($text, $target_encoding, $source_encoding);
  }
  return $text;
}

function _dgettext($domain, $msgid) {
    $l10n = _get_reader($domain);
    return _encode($l10n->translate($msgid),$domain);
}

function _dngettext($domain, $singular, $plural, $number) {
    $l10n = _get_reader($domain);
    return _encode($l10n->ngettext($singular, $plural, $number),$domain);
}

and so on for _dcgettext, _dcngettext, _dcpgettext, _dnpgettext, _dcnpgettext.