Re: [gnugo-devel] GNU Go 3.5.7 and latest CVS crash in KGS game

[Gunnar Farnebäck]

Arend wrote:
> The problem is a systematic hash collision, introduced by gunnar_5_7.11.
> Gunnar, the problem is with restoring the random state in both
> hash_init() and keyhash_init(): This means that both functions start
> with the same state of the pseudo random number generator, meaning that
> that they generate the same hash values. (In above position, the problem
> was that white_hash[] is up to a shift of a few entries identical to
> target1_hash[].)

Gah, I had already realized that this would happen but forgot to fix
it. :-(

> Since these two functions are only called from init_gnugo() via
> reading_cache_init(), and we call set_random_seed() right afterwards
> anyway, I think we can just drop the saving and restoring of the
> random state. Agree?

Ah, yes, the saving and restoring of random state has indeed become
superfluous by other changes.

/Gunnar