From: Marco Costalba <mcostalba@gmail.com>
Date: Sun, 29 Jan 2012 21:38:08 +0000 (+0100)
Subject: Fix bug in useless checks prune
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=df31398bb91b0e43661176e2f1681617ee64f1ad

Fix bug in useless checks prune

With current code we could raise bestValue above beta,
not what is intended for.

Spotted by Richard Vida.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---

diff --git a/src/search.cpp b/src/search.cpp
index 47971078..572a8ac8 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1282,12 +1282,7 @@ split_point_start: // At split points actual search starts from here
           && !pos.is_capture_or_promotion(move)
           &&  ss->eval + PawnValueMidgame / 4 < beta
           && !check_is_dangerous(pos, move, futilityBase, beta, &bestValue))
-      {
-          if (ss->eval + PawnValueMidgame / 4 > bestValue)
-              bestValue = ss->eval + PawnValueMidgame / 4;
-
           continue;
-      }
 
       // Check for legality only before to do the move
       if (!pos.pl_move_is_legal(move, ci.pinned))