(PR#10052) Apollo & Marco Polo work even when they should be obsolete

<URL: 
http://bugs.freeciv.org/Ticket/Display.html?id=10052
>

On Sun, 9 Jul 2006, Marko Lindqvist wrote:
> Marko Lindqvist wrote:
>>> Jason Short wrote:
>>>> But Marko Polo should make contact only
one-way, I thought?  That's the
>>>> way it was in the old code, and the way it
should be (it can be a big
>>>> disadvantage for other players to have
contact with you).
>>
>>   Patch
>
>  - Fixed is_valid_alliance() to handle one-way war.

I think this is extremely unwise. This game logic here is
already very 
complicated - and too complicated in my opinion. Having some
rare corner 
cases when contact can be one way only will be seriously
confusing and bug 
prone.

   - Per