Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!bloom-beacon!eru!luth!sunic!mcsun!ukc!dcl-cs!gdt!gdr!chpetk
From: chpetk@gdr.bath.ac.uk (Toby Kelsey)
Newsgroups: gnu.chess
Subject: Re: Gnuchess bug
Summary: Gnuchess bug correction
Keywords: gnuchess bug
Message-ID: <1989Nov28.190429.12089@gdt.bath.ac.uk>
Date: 28 Nov 89 19:04:29 GMT
References: <1989Nov27.204521.7311@Neon.Stanford.EDU>
Reply-To: chpetk@gdr.bath.ac.uk (Toby Kelsey)
Organization: School of Chemistry, University of Bath, UK
Lines: 30

In article <1989Nov27.204521.7311@Neon.Stanford.EDU> dalgic@bodega.stanford.edu (Ismail Dalgic) writes:
>I have the GnuChess version 1.53, and several times I noticed a very
>disturbing bug.  The program "forgets" about the piece in front of a
>pawn in its original rank when it advances the pawn by 2.

I came across the same bug. After looking at the code I found that the
making the following change to "move.c" corrected the error.

  - output of 'diff move.c move.c.old' -

335,336c335,336
<     while ((u != sq) && (color[u] == neutral)) {
<       LinkMove(ply,sq,u,xside);
---
>     while (u != sq) {
>       if (color[u] == neutral) LinkMove(ply,sq,u,xside);

This is in the pawn-move section (obviously!).
This makes it checks squares only until it reaches a non-empty one.

[ I'm not sure of my version, "gnuchess.c" mentions revision 4-25-88,
 and the last date in "CHANGES" is Aug. 1 '89 ]

>--Ismail Dalgic

 - Toby.
-- 
Toby Kelsey           UUCP : ...!ukc!gdr!chpetk
School of Chemistry,  DARPA: chpetk%gdr.bath.ac.uk@nsf-relay.ac.uk
University of Bath.   JANET: chpetk@uk.ac.bath.gdr


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