Forever loop in purge_issue_requests_curl() on localhost

This code seems to cause an endless loop on my localhost. Not have much time to investigate more into the issue but seems like it's caused by something related to this error message:

Warning: (null)(): xxx is not a valid cURL handle resource

do {
    // This loop is only necessary for libcurl earlier than 7.20.0, however
    // RHEL 5 has just that. Otherwise a simple call would do.
    do {
      $multi_result = curl_multi_exec($curl_purges, $active);
    } while ($multi_result == CURLM_CALL_MULTI_PERFORM);
    // Block until there is activity on any of the handlers. Avoids
    // busywaiting.
    if ($multi_result == CURLM_OK) {
      $select_result = curl_multi_select($curl_purges);
    }
    if ($multi_result != CURLM_OK || $select_result == -1) {
    // @TODO: error handling. Something truly awkward happened.
    return FALSE;
    }
  } while ($select_result != -1 && $active && $multi_result == CURLM_OK);