Make dir servers include a "Date:" http header more often

  o Minor bugfixes:

    - Directory servers now include a "Date:" http header for response

      codes other than 200. Clients starting with a skewed clock and a

      recent consensus were getting "304 Not modified" responses from

      directory authorities, so without a Date header the client would

      never hear about a wrong clock. Fixes bug 23499; bugfix on 0.0.8rc1.

write_http_status_line(dir_connection_t *conn, int status,

                       const char *reason_phrase)

{

  char buf[256];

  if (!reason_phrase)

  char buf[256+RFC1123_TIME_LEN+1];

  char *datestring = NULL;

  if (!reason_phrase) { /* bullet-proofing */

    reason_phrase = "unspecified";

  if (tor_snprintf(buf, sizeof(buf), "HTTP/1.0 %d %s\r\n\r\n",

      status, reason_phrase) < 0) {

  }

  if (server_mode(get_options())) {

    /* include the Date: header, but only if we're a relay or bridge */

    char datebuf[RFC1123_TIME_LEN+1];

    format_rfc1123_time(datebuf, time(NULL));

    tor_asprintf(&datestring, "Date: %s\r\n", datebuf);

  }

  if (tor_snprintf(buf, sizeof(buf), "HTTP/1.0 %d %s\r\n%s\r\n",

      status, reason_phrase, datestring?datestring:"") < 0) {

    log_warn(LD_BUG,"status line too long.");

    tor_free(datestring);

    return;

  }

  tor_free(datestring);

  log_debug(LD_DIRSERV,"Wrote status 'HTTP/1.0 %d %s'", status, reason_phrase);

  connection_buf_add(buf, strlen(buf), TO_CONN(conn));

}