[gnugo-devel] Extremely bad mistake

[Gunnar Farneback]

I was sent a game where GNU Go lost with 26 handicap stones due to a
repeated mistake. This is extremely bad. I would even say a
showstopper for 3.4. (I haven't checked it but would guess the semeai
code is at fault.)

/Gunnar

> One of my friend found a bug of Gnugo(3.3.19). Because of this bug, he
> won a handicap game with gnugo with 26 handicap stones. 
> 
> I attached the SGF file of this game. Hope it will be help for you and
> your team.
> 
> best regards,
> 
> phil

(;GM[1]FF[4]
SZ[19]HA[9]KM[0.5]
PW[qwert]WR[NR]
PB[ppmm (GNU Go 3.3.19)]BR[9k*]
PC[THQY]DT[2003-06-08]AP[gnugoclient:2.0]
RE[W+170.5]
AB[dd][jd][pd][dj][jj][pj][dp][jp][pp]
;W[];B[gj];W[];B[om];W[];B[go];W[];B[jg];W[];B[jm];W[];B[mj];W[]
;B[jq];W[];B[dc];W[];B[cg];W[];B[pq];W[];B[cj];W[];B[qj];W[];B[cp]
;W[];B[pc];W[];B[dg];W[];B[gg];W[];B[jc];W[fe];B[gd];W[ln];B[kn]
;W[bl];B[bn];W[db];B[eb];W[cb];B[ge];W[ce];B[bd];W[ec];B[fb];W[bc]
;B[be];W[cd];B[de];W[cc];B[cf];W[ef];B[ed];W[fh];B[ei];W[eh];B[dh]
;W[hi];B[ih];W[hh];B[hg];W[fi];B[hj];W[ej];B[ii];W[di];B[ci];W[ek]
;B[eg];W[fg];B[fo];W[dm];B[el];W[dl];B[mk];W[bh];B[bi];W[df];B[dk]
;W[gk];B[fl];W[fk];B[ol];W[gm];B[ik];W[en];B[bm];W[cl];B[hn];W[ad]
;B[af];W[bg];B[bf];W[aj];B[gf];W[ff];B[fd];W[ai];B[ei];W[fj];B[da]
;W[ca];B[ea];W[di];B[ah];W[al];B[ch];W[bj];B[ba];W[bb];B[ae];W[ck]
;B[ag];W[qn];B[ab];W[aa];B[ac];W[ad];B[ac];W[on];B[ro];W[rn];B[nn]
;W[oo];B[no];W[op];B[ab];W[ad];B[ac];W[nr];B[ab];W[ad];B[ac];W[np]
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;W[ir];B[jr];W[hq];B[es];W[er];B[ds];W[ep];B[eo];W[do];B[eq];W[cq]
;B[bq];W[dq];B[fq];W[bp];B[gr];W[co];B[ab];W[ad];B[ac];W[qf];B[of]
;W[qh];B[re];W[og];B[ri];W[nf];B[ng];W[oe];B[gq];W[nh];B[mg];W[pf]
;B[rg];W[nc];B[ab];W[ad];B[ac];W[rc];B[qe];W[lc];B[bs];W[aq];B[fs]
;W[mq];B[ab];W[ad];B[ac];W[ll];B[rl];W[km];B[ab];W[ad];B[ac];W[jl]
;B[il];W[hm];B[ab];W[ad];B[ac];W[kp];B[lo];W[jn];B[im];W[ko];B[lq]
;W[kq];B[mr];W[nq];B[lp];W[kr];B[lr];W[ks];B[hp];W[ms];B[rp];W[qr]
;B[pr];W[rs];B[mm];W[ls];B[kk];W[qo];B[ab];W[ad];B[ac];W[mh];B[ab]
;W[ad];B[ac];W[lg];B[js];W[io];B[ab];W[ad];B[ac];W[in];B[qp];W[sr]
;B[fp];W[ql];B[mn];W[ml];B[kl];W[rk];B[ab];W[ad];B[ac];W[rf];B[nl]
;W[lm];B[nm];W[rh];B[ab];W[ad];B[ac];W[rj];B[gn];W[fm];B[ab];W[ad]
;B[ac];W[nj];B[oj];W[pb];B[ab];W[ad];B[ac];W[ob];B[ab];W[ad];B[ac]
;W[ni];B[nk];W[ke];B[ab];W[ad];B[ac];W[je];B[qi];W[si];B[ab];W[ad]
;B[ac];W[if];B[ab];W[ad];B[ac];W[id];B[ab];W[ad];B[ac];W[ig];B[ab]
;W[ad];B[ac];W[hc];B[hb];W[gc];B[gb];W[fc];B[kb];W[hd];B[ei];W[bh]
;B[ab];W[ad];B[ac];W[di];B[ie];W[he];B[ei];W[gh];B[mb];W[lb];B[la]
;W[mc];B[ph];W[pg];B[ki];W[qk];B[lk];W[kn];B[pm];W[pk];B[ok];W[kh]
;B[jh];W[li];B[qm];W[rm];B[dp];W[nb];B[ma];W[kd];B[ic];W[lj];B[kj]
;W[oh];B[mi];W[lh];B[pn];W[po];B[na];W[ga];B[ha];W[kc];B[jb];W[ip]
;B[iq];W[ho];B[hr];W[gs];B[hs];W[oa];B[ka];W[hk];B[hl];W[gl];B[pi]
;W[jf];B[kg];W[kf];B[fn];W[gi];B[ij];W[ns];B[jo];W[ar];B[oi];W[cp]
;B[ep];W[as];B[gs];W[];B[pl];W[];B[]
C[R4 removed
K8 removed
J2 removed
B6 removed
E8 removed
C11 removed
E11 removed
A17 removed
D16 removed
final_score: W+170.5
G19 removed
Q17 removed
R15 removed
N13 removed
S13 removed
S8 removed]
)