Fix broken multi-pv with aspiration window search

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 6250f02fa4254718935c4fe48f72da7f4f71ab74..30abecd0ed563df77dd681af6f7429e1654b7bfc 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008 Marco Costalba
+  Copyright (C) 2008-2009 Marco Costalba
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -890,6 +890,10 @@ namespace {
 
         if (i < MultiPV)
         {
+            // Aspiration window is disabled in multi-pv case
+            if (MultiPV > 1)
+                alpha = -VALUE_INFINITE;
+
             value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0);
             // If the value has dropped a lot compared to the last iteration,
             // set the boolean variable Problem to true. This variable is used