Make should_set_md_dirserver_restriction() look at num filtered guards

  return rst;

}

/** If we have less than these many configured bridges, don't set dirserver

 *  restrictions because we might blacklist all of them. */

#define TOO_FEW_BRIDGES_FOR_RESTRICTION 10

/** If we have fewer than this many possible guards, don't set

 * MD-availability-based restrictions: we might blacklist all of

 * them. */

#define MIN_GUARDS_FOR_MD_RESTRICTION 10

/** Return true if we should set md dirserver restrictions. We might not want

 *  to set those if our network is too restricted, since we don't want to

{

  const guard_selection_t *gs = get_guard_selection_info();

  /* Don't set a restriction if we are on a restricted guard selection */

  if (gs->type == GS_TYPE_RESTRICTED) {

    return 0;

  }

  /* Don't set restriction if we are using bridges and have too few of those */

  if (gs->type == GS_TYPE_BRIDGE && gs->sampled_entry_guards) {

    int num_sampled_guards = smartlist_len(gs->sampled_entry_guards);

    if (num_sampled_guards < TOO_FEW_BRIDGES_FOR_RESTRICTION) {

      return 0;

    }

  /* Compute the number of filtered guards */

  int n_filtered_guards = 0;

  SMARTLIST_FOREACH_BEGIN(gs->sampled_entry_guards, entry_guard_t *, guard) {

    if (guard->is_filtered_guard) {

      ++n_filtered_guards;

    }

  } SMARTLIST_FOREACH_END(guard);

  return 1;

  /* Do we have enough filtered guards that we feel okay about blacklisting

   * some for MD restriction? */

  return (n_filtered_guards >= MIN_GUARDS_FOR_MD_RESTRICTION);

}

/** Allocate and return an outdated md guard restriction. Return NULL if no

  entry_guard_restriction_t *rst = NULL;

  if (!should_set_md_dirserver_restriction()) {

    log_debug(LD_GUARD, "Not setting md restriction: too few "

              "filtered guards.");

    return NULL;

  }