Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Bug in CHEST - bugfix available

Author: Dann Corbit

Date: 23:18:23 05/07/02

Go up one level in this thread


On May 08, 2002 at 01:31:36, Dann Corbit wrote:

>On May 07, 2002 at 15:09:57, Ernst Walet wrote:
>
>>On May 07, 2002 at 14:18:50, Dann Corbit wrote:
>>
>>>On May 05, 2002 at 13:55:00, Heiner Marxen wrote:
>>>
>>>>On April 28, 2002 at 22:00:22, Heiner Marxen wrote:
>>>>
>>>>>On April 28, 2002 at 18:18:38, Heiner Marxen wrote:
>>>>>
>>>>>>On April 28, 2002 at 08:00:15, Vincent Vega wrote:
>>>>>>
>>>>>>>Simplified position to show the bug:
>>>>>>>[D]8/8/8/8/8/8/4KP2/R1Qn3k w - - 0 1
>>>>>>>
>>>>>>>This is a mate in 2 (1. Qxd1+).
>>>>>>>
>>>>>>>But CHEST says:
>>>>>>>
>>>>>>>CHEST version 3.19, 18-Dec-1999
>>>>>>>Input file: 'xx'
>>>>>>>Reading job:
>>>>>>>#	xx
>>>>>>>W:  Ke2 Qc1 Ra1 Pf2 (4)
>>>>>>>B:  Kh1 Nd1 (2)
>>>>>>>FEN: 8/8/8/8/8/8/4KP2/R1Qn3k w - -
>>>>>>>analysing (mate in 2 moves):
>>>>>>>No solution in 2 moves.
>>>>>>>refu  1: Qxd1+   --      [  1-]   M2: move
>>>>>>>refu  2: Qc6+    --      [  1-]   M2: move
>>>>>>>refu  3: Qh6+    Kg1     [  1-]
>>>>>>>refu  4: f3      --      [  1-]   M2: move
>>>>>>>refu  5: f4      --      [  1-]   M2: move
>>>>>>>refu  6: Rb1     --      [  1-]   M2: move
>>>>>>>refu  7: Ra2     --      [  1-]   M2: move
>>>>>>>refu  8: Ra3     --      [  1-]   M2: move
>>>>>>>refu  9: Ra4     --      [  1-]   M2: move
>>>>>>>refu 10: Ra5     --      [  1-]   M2: move
>>>>>>>refu 11: Ra6     --      [  1-]   M2: move
>>>>>>>refu 12: Ra7     --      [  1-]   M2: move
>>>>>>>refu 13: Ra8     --      [  1-]   M2: move
>>>>>>>refu 14: Qb1     --      [  1-]   M2: move
>>>>>>>refu 15: Qc2     --      [  1-]   M2: move
>>>>>>>refu 16: Qc3     --      [  1-]   M2: move
>>>>>>>refu 17: Qc4     --      [  1-]   M2: move
>>>>>>>refu 18: Qc5     --      [  1-]   M2: move
>>>>>>>refu 19: Qc7     Kg1     [  1-]
>>>>>>>refu 20: Qc8     --      [  1-]   M2: move
>>>>>>>refu 21: Qd2     --      [  1-]   M2: move
>>>>>>>refu 22: Qe3     --      [  1-]   M2: move
>>>>>>>refu 23: Qf4     Kg1     [  1-]
>>>>>>>refu 24: Qg5     --      [  1-]   M2: move
>>>>>>>refu 25: Qb2     --      [  1-]   M2: move
>>>>>>>refu 26: Qa3     --      [  1-]   M2: move
>>>>>>>refu 27: Kd2     --      [  1-]   M2: move
>>>>>>>refu 28: Ke1     --      [  1-]   M2: move
>>>>>>>refu 29: Kf3     --      [  1-]   M2: move
>>>>>>>refu 30: Kxd1    --      [  1-]   M2: move
>>>>>>>refu 31: Kf1     Ne3+    [  1-]
>>>>>>>refu 32: Kd3     --      [  1-]   M2: move
>>>>>>>Time (virt) = 0.000 sec
>>>>>>
>>>>>>Sadly, I have to confirm this fact: this is a bug in Chest.
>>>>>>If I specify option "-2" to suppress the "2-mate-heuristic", it finds the
>>>>>>mate in 2:
>>>>>>
>>>>>> Qxd1+  Kh2    Qh1#
>>>>>>        Kg2    Qh1#
>>>>>>
>>>>>>Hence, the bug is in the "mate2" module.  Since that one is a really complex
>>>>>>one, it will take some time to track it down.
>>>>>>When I have found it, I will report under what circumstances it does appear.
>>>>>
>>>>>Fortunately, I could track down this bug.
>>>>
>>>>[snip]
>>>>>It is quite easy to correct this bug, and within the next week I will
>>>>>provide a corrected source module.
>>>>>It will be announced here, and be available through my web page.
>>>>
>>>>   http://www.drb.insel.de/~heiner/Chess/chest.html
>>>>
>>>>contains a reference to the corrected source code "mate2.c":
>>>>
>>>>   http://www.drb.insel.de/~heiner/Chess/mate2.c
>>>>
>>>>>Hopefully Dann will then provide a corrected win32 executable.
>>>>>Since the circumstances for the bug to occur are not really very rare,
>>>>>I'd recommend upgrading to the new version when available.
>>>>
>>>>I can't speak for Dann, but it would be very nice of him to offer
>>>>an updated source package, and more importantly, a corrected binary.
>>>>(I myself cannot compile for windows).
>>>
>>>Everything:
>>>ftp://cap.connx.com/pub/chess-solvers/chest/
>>>
>>>The package in a zip:
>>>ftp://cap.connx.com/pub/chess-solvers/chest/CHEST319.ZIP
>>>
>>>The binary only:
>>>ftp://cap.connx.com/pub/chess-solvers/chest/chest319.exe
>>
>>
>>Dan, when accessing the first link, I immediately get attacked by a trojan
>>horse.  This is the message drom my fire wall:
>>
>>Soket de Trois v1. Trojan horse at cap.connx.com (209.20.248.158)
>>
>>Maybe you should check your server?
>
>I shut down my ftp site, and I am running the virus scanner over all drives.
>Pretty strange that it did not get diagnosed.
>I have McAfee Virus Scan 4.5.1, and it gets updated over the net every night.

I searched my registry for mschv32.* and did not find anything.
I searched all hard drives my system has access to for mschv32.* and it is not
found anywhere.

I have several million files on my total available disk storage, so the virus
scan will run for 15 hours or so.



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.