From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Sat, 31 Oct 2020 12:24:43 +0000 (+0100)
Subject: Fix failing assertion in losers chess
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=252bc6b66571fcb0247c8956b8174db83033efe9;p=fairystockfish.git

Fix failing assertion in losers chess

Prevent non-evasion move generation when in check.
---

diff --git a/src/search.cpp b/src/search.cpp
index cafb11a..0878a93 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1202,7 +1202,7 @@ moves_loop: // When in check, search starts from here
       // Losing chess capture extension
       else if (    pos.must_capture()
                &&  pos.capture(move)
-               &&  MoveList<CAPTURES>(pos).size() == 1)
+               &&  (ss->inCheck || MoveList<CAPTURES>(pos).size() == 1))
           extension = 1;
 
       // Add extension to new depth
@@ -1230,7 +1230,7 @@ moves_loop: // When in check, search starts from here
               || ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
               || cutNode
               || thisThread->ttHitAverage < 427 * TtHitAverageResolution * TtHitAverageWindow / 1024)
-          && !(pos.must_capture() && MoveList<CAPTURES>(pos).size()))
+          && !(pos.must_capture() && (givesCheck || MoveList<CAPTURES>(pos).size())))
       {
           Depth r = reduction(improving, depth, moveCount);