[gnugo-devel] Crash

[bump]

The following gtp sequence produces a crash:

loadsgf golois/Aya991113-2.sgf
query_boardsize
top_moves_black
black S12
estimate_score
undo
black O4
showboard
estimate_score

Here's the output of the final showboard and the crash
diagnostics. The black S12 was previously tried and
undone. It is not on the board but has been tried by
do_owl_attack. Backtrace at bottom. The crash does
not occur if the call to top_moves_black is eliminated.
I used out-of-the-box 3.2 to generate this backtrace,
I suppose current CVS line numbers could differ.

Dan

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

***assertion failure:
board.c:2097 - board[pos] == EMPTY near S12***

B:S12 
   A B C D E F G H J K L M N O P Q R S T
19 . . . . . . . . . . . . . . . . . . . 19
18 . . . . . . . . X . . . . . . . . . . 18
17 . . X . . . X . . . X . O . . O . . . 17
16 . . . + O . . . . + . . . . . + . . . 16
15 . . . . . . . . . . . . . . . . O . . 15
14 . . X . . . . . . . . . . . . . . . . 14
13 . . . . . . . . . . O . . . . . . O . 13
12 . . . . . . . . . . . . . . . . X X . 12
11 . . X . . . . . . . . . . . . X O O . 11     WHITE has captured 0 stones
10 . . . + . . . . . + . . . . . + X X . 10     BLACK has captured 0 stones
 9 . . . . . . . . . . . . . . . . X . . 9
 8 . . . . . . . . . . . . . . O X X O . 8
 7 . . . . . . . . . . . . . . O X O O . 7
 6 . . X . . . . . . . . . . . O X X O . 6
 5 . . . . . . . . . . . . . O X . X O . 5
 4 . . . + O . . . . + . . O X X X O O . 4
 3 . . X . . . X . X . O . O X O O O . . 3
 2 . . . . . . . . . . . . . X . X . . . 2
 1 . . . . . . . . . . . . . . . . . . . 1
   A B C D E F G H J K L M N O P Q R S T
   A B C D E F G H J K L M N O P Q R S T
19 . . . . . . . . . . . . . . . . . . . 19
18 . . . . . . . . X . . . . . . . . . . 18
17 . . X . . . X . . . X . O . . O . . . 17
16 . . . + O . . . . + . . . . . + . . . 16
15 . . . . . . . . . . . . . . . . O . . 15
14 . . X . . . . . . . . . . . . . . . . 14
13 . . . . . . . . . . O . . . . . . O . 13
12 . . . . . . . . . . . . . . . . X . . 12
11 . . X . . . . . . . . . . . . X O O . 11     WHITE has captured 0 stones
10 . . . + . . . . . + . . . . . + X X . 10     BLACK has captured 0 stones
 9 . . . . . . . . . . . . . . . . X . . 9
 8 . . . . . . . . . . . . . . O X X O . 8
 7 . . . . . . . . . . . . . . O X O O . 7
 6 . . X . . . . . . . . . . . O X X O . 6
 5 . . . . . . . . . . . . . O X . X O . 5
 4 . . . + O . . . . + . . O X X X O O . 4
 3 . . X . . . X . X . O . O X O O O . . 3
 2 . . . . . . . . . . . . . X . X . . . 2
 1 . . . . . . . . . . . . . . . . . . . 1
   A B C D E F G H J K L M N O P Q R S T

gnugo 3.2 (seed 1020176234): You stepped on a bug.
Please save this game as an sgf file and mail it to address@hidden
If you can, please also include the debug output above this message.

Program received signal SIGABRT, Aborted.
0x400c5a01 in __kill () from /lib/i686/libc.so.6
(gdb) bt
#0  0x400c5a01 in __kill () from /lib/i686/libc.so.6
#1  0x400c57da in raise (sig=6) at ../sysdeps/posix/raise.c:27
#2  0x400c6f82 in abort () at ../sysdeps/generic/abort.c:88
#3  0x08057ead in approxlib (pos=178, color=1, maxlib=2, libs=0x0)
    at board.c:2097
#4  0x0807a41f in do_owl_defend (str=197, move=0x0, owl=0x409e3c0c, 
    komaster=0, kom_pos=0) at owl.c:2045
#5  0x080792c7 in do_owl_attack (str=197, move=0xbfffec0c, owl=0x409e3c0c, 
    komaster=0, kom_pos=0) at owl.c:1537
#6  0x0807876a in owl_attack (target=197, attack_point=0xbfffecbc, 
    certain=0x8596a7c) at owl.c:1125
#7  0x08061f01 in make_dragons (color=1, stop_before_owl=0, save_verbose=0)
    at dragon.c:424
#8  0x080650e0 in examine_position (color=1, how_much=4) at genmove.c:147
#9  0x0806522a in silent_examine_position (color=1, how_much=4)
    at genmove.c:198
#10 0x0805036f in gtp_estimate_score (s=0xbffff41f "", id=-1)
    at play_gtp.c:2125
#11 0x080539fd in gtp_main_loop (commands=0x80f5f78, gtp_input=0x401cb000)
    at gtp.c:104
#12 0x0804aa64 in main (argc=4, argv=0xbffffa14) at main.c:1114
#13 0x400b3507 in __libc_start_main (main=0x80491e0 <main>, argc=4, 
    ubp_av=0xbffffa14, init=0x8048d68 <_init>, fini=0x80d5140 <_fini>, 
    rtld_fini=0x4000dc14 <_dl_fini>, stack_end=0xbffffa0c)
    at ../sysdeps/generic/libc-start.c:129