[Freeciv-Dev] Re: civserver segfault with new research system (PR#1221)

[Gregory Berkolaiko <gberkolaiko@xxxxxxxxxxx>]

 --- Raimar Falke <hawk@xxxxxxxxxxxxxxxxxxxxxxx> wrote: 
> On Sat, Jan 12, 2002 at 05:14:51PM +0000, Gregory Berkolaiko wrote:
> >
> > Do barbarians research at all?
> 
> That is the question.

Maybe Tony can help?
They certainly possess knowledge but do they research?

> 
> > Why did you put the assert in the first place?
> 
> get_num_human_and_ai_players() returns 0 for them. Divide by zero.

I see
Wait, what do you mean "returns 0 _for_them_"?  It would return 0 in a
barbarian-only game, would it not terminate?  Probably not, it will carry
on forever...

[..]

> It was initially a switch statement. I converted it. Because there
> were duplicated code: future techs are the same as style 0 and style 2
> is style 1 is there are unset values.

Yes, I thought about it and arrived to the conclusion that introducing
the variable tech_style = game.rgame.tech_cost_style, doing two ifs:
if (tech > game.num_tech_types) {
  /* Future techs evaluated in style 0 */
  tech_style = 0;
}

if (tech_style == 2 && advances[tech].preset_cost == -1) {
  /* No preset, using style 1 */
  tech_style = 1;
}

and then doing the switch is still better.  In this way the exceptions 
are clearly separated and documented, not mixed in with the main ifs.

Personally I always struggle to understand else-if statements.

And in the tech_leakage case there are no exceptions to care about! 
Unless you decide to do 

if (is_barbarian(pplayer)) {
  /* Barbarians don't talk to anyone (can't speak that's why) */
  tech_leakage = 0;
}

which is also not too bad.

Also occured to me: you don't have embassy with yourself, do you?
Thus in 
  cost = ((players - players_with_tech) * cost) / players;
we are potentially dividing by zero (if have embassy with noone).


Best,
G.

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