From: H.G.Muller <hgm@hgm-xboard.(none)>
Date: Mon, 15 May 2017 13:00:02 +0000 (+0200)
Subject: Fix spurious PV after repeat
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=bcb64f0179c77e5d6c91902711b5c3bd539d4a7d;p=crazywa.git

Fix spurious PV after repeat

We simulate return of an empty PV when a move is pruned because
of a repetition.
---

diff --git a/dropper.c b/dropper.c
index 71342af..ced95b2 100644
--- a/dropper.c
+++ b/dropper.c
@@ -1352,6 +1352,7 @@ if(PATH)printf("%d:%d:%d new iter moveStack[%d..%d]\n",ply,depth,iterDepth,m.fir
 		    else if(gain == pawn  || gain >= (400<<21)) score = INF-1;  // quasi-repeat with extra piece in hand
 		    else if(gain == -pawn || gain <= (-400<<21)) score = 1-INF; // or with one piece less
 		    else goto search;// traded one hand piece for another; could still lead somewhere
+		    *pvPtr = 0; // fake that daughter returned empty PV
 		} else { // not a repeat: search it
 		    int lmr;
 		  search: