Re: [gnugo-devel] segfault - "--decide-dragon xx -a -t" with certain board positions

[Gunnar Farnebäck]

Winsor C wrote:
> Seems like some boards position causes GNU Go 3.80 to go segfault with
> "--decide-dragon xx -a -t" options.
> For example, save the following as "a.sgf"
>
> -----begin of a.sgf-----
> (;FF[4]CA[UTF-8]
> KM[6.5]
> ;B[pd];W[dd];B[ip];W[pp];B[np];W[dp];B[pn];W[qi];B[qq];W[oo]
> ;B[qp];W[nc];B[qf];W[jd];B[ql];W[gq];B[ci];W[ir];B[mn];W[on]
> ;B[om];W[ld];B[fc];W[cp];B[cf];W[dl];B[ee];W[cc];B[hc];W[jc]
> ;B[oc];W[nd];B[oi];W[pj];B[ok];W[ph];B[og];W[kq])
> -----end of a.sgf-----
>
> Run this:
> ./gnugo -l a.sgf -L 34 --decide-dragon r11 -a -t

Thanks for the report. I can confirm the crash and located it to
check_pattern_hard() in owl.c, which is called with a null pattern. I
need to investigare further to determine why this is happening and
what is supposed to happen with traces turned on.

/Gunnar