[Freeciv-Dev] Re: Reproducable core dump (PR#1051)

[Raimar Falke <hawk@xxxxxxxxxxxxxxxxxxxxxxx>]

On Tue, Nov 27, 2001 at 11:16:06AM -0800, jdorje@xxxxxxxxxxxxxxxxxxxxx wrote:
> Gregory Berkolaiko wrote
> 
> >  --- jdorje@xxxxxxxxxxxxxxxxxxxxx wrote: 
> >>Gregory Berkolaiko wrot
> 
> 
> >>>2. This piece of code is used by human palyers (AI doesn't fly) but
> >>>it peeks under the FOW absolutely shamelessly.  You don't attempt to
> >>>fix it.
> >>>Why not?
> >>>
> >>
> >>Ouch.  I did not realize this was a problem - I just blindly duplicated
> >>the original functionality :-(.  The goto should also avoid going
> >>across unknown tiles, right?
> >>
> > 
> > It is a problem, largerly unfixed.  I have a patch fixing it in
> > find_the_best_path, but it's in the waiting.
> > 
> > As for unknown tiles, there is a comment at
> > http://www.freeciv.org/lxr/source/server/gotohand.c?v=cvs#L763
> > with which I agree.  There is also a maximalist's and minimalist's
> > approach to the problem of avoiding enemy.  You seem to follow
> > maximalist: if you don't know the tile, you assume it's enemy-occupied. 
> > I think it is more wise to do the minimalist's "if I don't see the enemy,
> > I hope it's not there" approach with the planes, otherwise you don't get
> > anywhere (in particular to some airfield -- it doesn't give you vision). 
> > So what I had in mind is more like: 
> > if (!MAPSTEP(nx, ny, x, y, dir) ||
> >      (map_get_known_and_seen(nx, ny, pplayer) 
> >     && is_non_allied_unit_tile(map_get_tile(nx, ny), pplayer)
> >     && !((nx==dest_x) && (ny==dest_y))))  {
> >   break;
> > }
> > Note that we don't care if our destination is occupied !
> 
> 
> Hmm, I'll have to double-check the destination occupied situation.
> 
> My current implementation isn't completely minimalist: it will refuse to 
> fly through unknown tiles but will happily fly through known, fogged 
> tiles assuming no enemy is there.  Is this wise?  Really, a fogged tile 
> is just as likely to contain an enemy as an unknown tile.

A nice goal may be to have this behavior changeable by function
arguments.

        Raimar

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