[gnugo-devel] Linear eye space

[Daniel Bump]

In 3.1.15 there was this ChangeLog entry:

- support for marginal eye points with opponent stones in eyes.db

In the course of debugging a revision of owl_analyze_semeai I
got a crash in this position:

(;GM[1]FF[3]
SZ[19]KM[0];
C[do_owl_analyze_semeai S8: WIN S9 (D206)
do_owl_analyze_semeai R8: WIN T7 (safe outside liberty)]
AW[mb][nb][rb][ec][oc][pc][rc][bd][cd][ed][gd][hd][id][jd][qd][ce][ee][pe][qe][re][df][if][jf][dg][hg][ig][lg][og][qg][bh][ch][dh][fh][gh][jh][oh][ei][ni][oi][ej][fj][nj][pj][gk][hk][kk][lk][mk][pk][il][jl][ll][pl][rl][hm][km][lm][qm][rm][dn][gn][in][qn][eo][fo][qo][ep][hp][lp][np][op][fq][gq][lq][mq][pq][qq][rq][fr][kr][fs][js]
AB[eb][gb][lb][qb][cc][dc][hc][ic][kc][mc][qc][ad][dd][nd][od][pd][rd][be][de][ke][af][cf][ef][ff][gf][hf][mf][bg][cg][gg][mg][hh][ih][lh][nh][gi][hi][ji][ki][mi][qi][hj][ij][kj][mj][qj][bk][dk][ek][ik][jk][nk][qk][fl][gl][hl][nl][ql][cm][pm][kn][mn][nn][pn][sn][bo][jo][lo][po][dp][fp][jp][mp][pp][qp][rp][cq][eq][er][hr][ir][jr][gs]
PL[2];W[rk];B[ri];W[rj];B[sj];W[rh]
)

The W dragon at S10 has a marginal eyespace of size 4 at
T10,T9,T8,T7. When owl_determine_life is called on this
it returns attack/defense points both at T10, which is
occupied. Of course, this is bad behavior.

It looks like linear_eye_space needs some revision which I'll 
undertake tonight.

In 3.1.15 there was this ChangeLog entry:

- support for marginal eye points with opponent stones in eyes.db

I suppose this is fallout from this change in gunnar_1_15.1.

Dan