[gnugo-devel] assertion failure in the board code

[Gunnar Farneback]

The appended GTP script causes an assertion failure deep down in the
board code:

***assertion failure:
board.c:4407 - s >= 0 near PASS***


   A B C D E F G H J K L M N O P Q R S T
19 . X X X . X X X . X X X X X . X X . X 19
18 X X X . X . X X X X X . X X X X X . X 18
17 X . X X X X . . X X . X X X X . X X X 17
16 . X X X . X X . X X X . X X X X X . X 16
15 X X X X X X . X X . X X . X . . X X X 15
14 X . X . X X X X X X . X . X X X X X X 14
13 X X X X X X . X . X X . X . X X X X . 13
12 . X . X X X X . X X X X X X X . X X X 12
11 X X X . X . X X X . . X . X . . X X X 11     WHITE has captured 0 stones
10 X X X X X X . X X + X . X . X X X . X 10     BLACK has captured 0 stones
 9 . X X X X . X . X X X X X X X X X X . 9
 8 X X . X X X X X X X X . X X X X . X X 8
 7 X . X . X X X . . . X X . X X . X X X 7
 6 . X . X X . X X X X X X X X . X X X . 6
 5 X X . X X . . X . X X X X X X . X X . 5
 4 . X X X X X X X X X . X X . X + X X X 4
 3 X X . X X X X X X . X . X X X X X X X 3
 2 X X X . X . X X . X X X X . . X X . X 2
 1 . X . X X X X . X X . X X . X X X . X 1
   A B C D E F G H J K L M N O P Q R S T

The position is somewhat extreme so it's possible that some assumption
has turned out to be too optimistic. Unfortunately I haven't been able
to reduce the test case further and just removing a single genmove
seems to suffice to no longer trigger the bug.

Needless to say, this shouldn't happen.

(For what it's worth, valgrind reports no errors up to command 503.)

/Gunnar

1 boardsize 19
2 clear_board
3 komi 0.5
4 play black Q19
5 play black T19
6 play black A18
7 play black C18
8 play black R18
9 play black T18
10 play black K17
11 play black R17
12 play black D16
13 play black N16
14 play black P16
15 play black C15
16 play black E15
17 play black H14
18 play black K14
19 play black P14
20 play black B13
21 play black K13
22 play black J12
23 play black K12
24 play black P12
25 play black G11
26 play black T11
27 play black F10
28 play black H10
29 play black N10
30 play black A8
31 play black C7
32 play black B6
33 play black G6
34 play black M6
35 play black O6
36 play black G4
37 play black H3
38 play black L2
39 genmove white
40 play black L10
41 genmove white
42 play black E4
43 genmove white
44 play black E11
45 genmove white
46 play black L9
47 genmove white
48 play black P13
49 genmove white
50 play black E13
51 genmove white
52 play black D8
53 genmove white
54 play black B5
55 genmove white
56 play black S4
57 genmove white
58 play black C19
59 genmove white
60 play black S13
61 genmove white
62 play black A13
63 genmove white
64 play black P7
65 genmove white
66 play black M17
67 genmove white
68 play black H5
69 genmove white
70 play black E12
71 genmove white
72 play black E10
73 genmove white
74 play black E7
75 genmove white
76 play black S8
77 genmove white
78 play black H11
79 genmove white
80 play black J1
81 genmove white
82 play black K9
83 genmove white
84 play black G3
85 genmove white
86 play black R14
87 genmove white
88 play black G7
89 genmove white
90 play black R13
91 genmove white
92 play black D3
93 genmove white
94 play black N3
95 genmove white
96 play black N6
97 genmove white
98 play black P8
99 genmove white
100 play black B19
101 genmove white
102 play black C13
103 genmove white
104 play black F19
105 genmove white
106 play black D6
107 genmove white
108 play black F7
109 genmove white
110 play black Q10
111 genmove white
112 play black C2
113 genmove white
114 play black R9
115 genmove white
116 play black A14
117 genmove white
118 play black N9
119 genmove white
120 play black Q2
121 genmove white
122 play black T17
123 genmove white
124 play black O9
125 genmove white
126 play black E8
127 genmove white
128 play black C11
129 genmove white
130 play black Q13
131 genmove white
132 play black H18
133 genmove white
134 play black C17
135 genmove white
136 play black J17
137 genmove white
138 play black O15
139 genmove white
140 play black S9
141 genmove white
142 play black H4
143 genmove white
144 play black M11
145 genmove white
146 play black P18
147 genmove white
148 play black B18
149 genmove white
150 play black F14
151 genmove white
152 play black D9
153 genmove white
154 play black M14
155 genmove white
156 play black Q16
157 genmove white
158 play black D4
159 genmove white
160 play black O19
161 genmove white
162 play black R3
163 genmove white
164 play black O8
165 genmove white
166 play black J4
167 genmove white
168 play black K1
169 genmove white
170 play black Q1
171 genmove white
172 play black Q18
173 genmove white
174 play black S3
175 genmove white
176 play black G19
177 genmove white
178 play black N2
179 genmove white
180 play black M7
181 genmove white
182 play black G1
183 genmove white
184 play black D17
185 genmove white
186 play black Q9
187 genmove white
188 play black S12
189 genmove white
190 play black L6
191 genmove white
192 play black T8
193 genmove white
194 play black Q6
195 genmove white
196 play black G16
197 genmove white
198 play black F16
199 genmove white
200 play black T12
201 genmove white
202 play black L16
203 genmove white
204 play black E9
205 genmove white
206 play black B11
207 genmove white
208 play black N5
209 genmove white
210 play black G2
211 genmove white
212 play black B8
213 genmove white
214 play black A3
215 genmove white
216 play black S6
217 genmove white
218 play black R2
219 genmove white
220 play black E17
221 genmove white
222 play black H19
223 genmove white
224 play black T3
225 genmove white
226 play black L18
227 genmove white
228 play black G8
229 genmove white
230 play black B15
231 genmove white
232 play black M15
233 genmove white
234 play black L8
235 genmove white
236 play black H2
237 genmove white
238 play black D13
239 genmove white
240 play black R11
241 genmove white
242 play black N17
243 genmove white
244 play black L7
245 genmove white
246 play black R1
247 genmove white
248 play black A11
249 genmove white
250 play black T1
251 genmove white
252 play black O18
253 genmove white
254 play black F1
255 genmove white
256 play black C4
257 genmove white
258 play black M5
259 genmove white
260 play black M9
261 genmove white
262 play black K2
263 genmove white
264 play black O14
265 genmove white
266 play black F8
267 genmove white
268 play black L3
269 genmove white
270 play black E14
271 genmove white
272 play black P3
273 genmove white
274 play black L12
275 genmove white
276 play black S5
277 genmove white
278 play black R5
279 genmove white
280 play black D5
281 genmove white
282 play black J16
283 genmove white
284 play black M4
285 genmove white
286 play black O16
287 genmove white
288 play black O11
289 genmove white
290 play black F4
291 genmove white
292 play black S14
293 genmove white
294 play black P9
295 genmove white
296 play black M2
297 genmove white
298 play black T15
299 genmove white
300 play black K5
301 genmove white
302 play black D15
303 genmove white
304 play black A15
305 genmove white
306 play black R12
307 genmove white
308 play black R16
309 genmove white
310 play black T10
311 genmove white
312 play black E18
313 genmove white
314 play black K4
315 genmove white
316 play black A17
317 genmove white
318 play black Q8
319 genmove white
320 play black B12
321 genmove white
322 play black E5
323 genmove white
324 play black M12
325 genmove white
326 play black J3
327 genmove white
328 play black J15
329 genmove white
330 play black N18
331 genmove white
332 play black E2
333 genmove white
334 play black F13
335 genmove white
336 play black A10
337 genmove white
338 play black O12
339 genmove white
340 play black N19
341 genmove white
342 play black L13
343 genmove white
344 play black O17
345 genmove white
346 play black G12
347 genmove white
348 play black G9
349 genmove white
350 play black B9
351 genmove white
352 play black H6
353 genmove white
354 play black Q14
355 genmove white
356 play black B2
357 genmove white
358 play black K8
359 genmove white
360 play black L15
361 genmove white
362 play black A5
363 genmove white
364 play black J10
365 genmove white
366 play black Q3
367 genmove white
368 play black J6
369 genmove white
370 play black C16
371 genmove white
372 play black J9
373 genmove white
374 play black B10
375 genmove white
376 play black R4
377 genmove white
378 play black J14
379 genmove white
380 play black C10
381 genmove white
382 play black K18
383 genmove white
384 play black P10
385 genmove white
386 play black G14
387 genmove white
388 play black N12
389 genmove white
390 play black J18
391 genmove white
392 play black P1
393 genmove white
394 play black R10
395 genmove white
396 play black A7
397 genmove white
398 play black H15
399 genmove white
400 play black N4
401 genmove white
402 play black C9
403 genmove white
404 play black P17
405 genmove white
406 play black E3
407 genmove white
408 play black D19
409 genmove white
410 play black O3
411 genmove white
412 play black E1
413 genmove white
414 play black F17
415 genmove white
416 play black N8
417 genmove white
418 play black R19
419 genmove white
420 play black L5
421 genmove white
422 play black A2
423 genmove white
424 play black G18
425 genmove white
426 play black D1
427 genmove white
428 play black T14
429 genmove white
430 play black H8
431 genmove white
432 play black K19
433 genmove white
434 play black S11
435 genmove white
436 play black F15
437 genmove white
438 play black B16
439 genmove white
440 play black B3
441 genmove white
442 play black T7
443 genmove white
444 play black L19
445 genmove white
446 play black D10
447 genmove white
448 play black E6
449 genmove white
450 play black T4
451 genmove white
452 play black M1
453 genmove white
454 play black F12
455 genmove white
456 play black N1
457 genmove white
458 play black C14
459 genmove white
460 play black O5
461 genmove white
462 play black D12
463 genmove white
464 play black H13
465 genmove white
466 play black M19
467 genmove white
468 play black S7
469 genmove white
470 play black O7
471 genmove white
472 play black N13
473 genmove white
474 play black P4
475 genmove white
476 play black P5
477 genmove white
478 play black B1
479 genmove white
480 play black B4
481 genmove white
482 play black F3
483 genmove white
484 play black K16
485 genmove white
486 play black K6
487 genmove white
488 play black J11
489 genmove white
490 play black J8
491 genmove white
492 play black R6
493 genmove white
494 play black R7
495 genmove white
496 play black T16
497 genmove white
498 play black S15
499 genmove white
500 play black T2
501 genmove white
502 play black S17
503 genmove white
504 play black R15