char *Curl_checkProxyheaders(struct Curl_easy *data,
                             const struct connectdata *conn,
                             const char *thisheader,
                             const size_t thislen)
{
  struct curl_slist *head;

  for(head = (conn->bits.proxy && data->set.sep_headers) ?
        data->set.proxyheaders : data->set.headers;
      head; head = head->next) {
    if(strncasecompare(head->data, thisheader, thislen) &&
       Curl_headersep(head->data[thislen]))
      return head->data;
  }

  return NULL;
}
char *Curl_checkProxyheaders(struct Curl_easy *data,
                             const struct connectdata *conn,
                             const char *thisheader,
                             const size_t thislen)
{
  struct curl_slist *head;

  for(head = (conn->bits.proxy && data->set.sep_headers) ?
        data->set.proxyheaders : data->set.headers;
      head; head = head->next) {
    if(strncasecompare(head->data, thisheader, thislen) &&
       Curl_headersep(head->data[thislen]))
      return head->data;
  }

  return NULL;
}