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Subject: Re: Bug in CHEST - bugfix available

Author: Dann Corbit

Date: 23:26:52 05/07/02

Go up one level in this thread


On May 08, 2002 at 02:18:23, Dann Corbit wrote:

>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.

None of the following are located anywhere on my system:

rsrcload.exe
mgadeskdll.exe
csmctrl32.exe

So it would appear that I do not have any of the variants.
Still running the virus scanner (which won't complete until tomorrow)



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