[Freeciv-Dev] Re: cma bug? (PR#1864) + stealth fighter bug

[Mateusz Stefek <matusik_s@xxxxx>]

> On Mon, Aug 05, 2002 at 02:49:09PM +0300, Jussi Asp wrote:
> > Other bug we saw was ghost-stealth fighters, which were seen on map
> but
> > they weren't there if you tried to attack them, and they stayed
> there
> > for many turns. Or maybe it's a feature, how is stealth supposed to
> > work, I don't know..
>
>         It's not how stealth is supposed to work.
>         That said, there may be many different ways such a bug could
> come
> about.  Units which were sighted, avoided, and are now in a
> non-updated or
> Fog of War-covered area should remain visible on the map until that
> tile is
> sighted again and they are proven to be gone.  Something might be
> failing
> to remove units in the proof stage.
>         There have been examples in the past of people mistyping
> X-axis and
> Y-axis coordinate references.  We might have such a transposition
> somewhere
> in the current client.
>
>         I consider both of these unlikely, but they are both obvious
> explanations for behavior similar to what you describe.
Take a look at server/unittools.c:1998 : 
/**************************************************************************
  Send the unit into to those connections in dest which can see the 
units
  position, or the specified (x,y) (if different).
  Eg, use x and y as where the unit came from, so that the info can be
  sent if the other players can see either the target or destination 
tile.
  dest = NULL means all connections (game.game_connections)
**************************************************************************/
void send_unit_info_to_onlookers(struct conn_list *dest, struct unit 
*punit,
				 int x, int y, bool carried, bool 
select_it)
{
  struct packet_unit_info info;

  if (!dest) dest = &game.game_connections;
    package_unit(punit, &info, carried, select_it,
               UNIT_INFO_IDENTITY, FALSE, FALSE);

  conn_list_iterate(*dest, pconn) {
    struct player *pplayer = pconn->player;
    if (!pplayer && !pconn->observer) continue;
!!!!!!    if (!pplayer || ((map_get_known_and_seen(info.x, info.y, 
pplayer)
                      || map_get_known_and_seen(x, y, pplayer))
                     && player_can_see_unit(pplayer, punit))) {
      send_packet_unit_info(pconn, &info);!!!!!!!!!
    }
  }
  conn_list_iterate_end;
}

send_unit_info_to_onlookers() is called from move_unit() with x = src_x 
and y = src_y.
if *pplayer can_see_unit on (src_x, src_y) but !can_see_unit now he 
doesn't receive
it's info. So the client thinks that the unit stays on (src_x, src_y) 
until it
receives new unit info(sometimes it's impossible).

See the patch
--
mateusz

ghost-unit1.diff
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