$NetBSD: patch-ac,v 1.2 2007/12/17 18:55:32 drochner Exp $

--- src/boards/chess_notation.c.orig	2007-08-31 00:52:28.000000000 +0200
+++ src/boards/chess_notation.c
@@ -203,7 +203,7 @@ piece_to_ascii (int piece)
   if(WPIECE(piece))
     return piece_to_ascii_full[i];
   else
-    return tolower(piece_to_ascii_full[i]);
+    return tolower((unsigned char)piece_to_ascii_full[i]);
 
   g_assert_not_reached ();
 
