Re: [gnugo-devel] bug report: ***assertion failure: combination.c:418

[Daniel Bump]

> 1. Pulled the most recent gnugo from savannah using git and compiled it.
> 2. copied the SGF info into a file name e.g. "bad.sgf"
> 3. loaded the file up into gnugo using `gnugo --mode gtp -l bad.sgf
> 4. typed `aa_confirm_safety b P2`

Thanks.

This does produce a crash. It is a somewhat artificial
situation since you are asking to confirm the safety of
a move at P2 but P2 is already occupied.

So this is not a crash that should happen as a result
of normal move generation. 

The abort is at line 418 of combination.c. My opinion
is that this should be fixed in the unstable line, but
it doesn't need to be fixed for GNU Go 3.8. Not because
it isn't worth fixing - just because it is conservative
to minimize changes to the engine just before a stable
release.

Backtrace below.

Dan


#0  0xb7f31410 in __kernel_vsyscall ()
#1  0xb7da5085 in raise () from /lib/tls/i686/cmov/libc.so.6
#2  0xb7da6a01 in abort () from /lib/tls/i686/cmov/libc.so.6
#3  0x080aa4c4 in abortgo (file=0x8128420 "combination.c", line=418, 
msg=0x8128418 "trymove", pos=375) at printutils.c:297
#4  0x0806d72b in atari_atari_blunder_size (color=2, move=375, 
defense_moves=0xbfcb1d04 "\005", safe_stones=0xbfcb1e94 "����\003") at 
combination.c:418
#5  0x0806d59a in atari_atari_confirm_safety (color=2, move=375, 
defense=0xbfcb2064, minsize=0, saved_dragons=0xbfcb2210 "", 
saved_worms=0xbfcb2080 "") at combination.c:370
#6  0x080545ba in gtp_aa_confirm_safety (s=0xbfcb27ee "b p2\n") at 
play_gtp.c:2477
#7  0x0805ba58 in gtp_main_loop (commands=0x84f2260, gtp_input=0xb7ec5440, 
gtp_output=0xb7ec54e0, gtp_dump_commands=0x0) at gtp.c:142
#8  0x0804fca6 in play_gtp (gtp_input=0xb7ec5440, gtp_output=0xb7ec54e0, 
gtp_dump_commands=0x0, gtp_initial_orientation=0) at play_gtp.c:353
#9  0x0804b9ff in main (argc=5, argv=0xbfcb2f14) at main.c:1431
(gdb) f 4
#4  0x0806d72b in atari_atari_blunder_size (color=2, move=375, 
defense_moves=0xbfcb1d04 "\005", safe_stones=0xbfcb1e94 "����\003") at 
combination.c:418