From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Tue, 31 Mar 2020 18:31:57 +0000 (+0200)
Subject: Prohibit non-passing moves not breaking bikjang
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=41d937b36b8bdf76c601e3974a9c32da56879827;p=fairystockfish.git

Prohibit non-passing moves not breaking bikjang

Closes #92.
---

diff --git a/src/position.cpp b/src/position.cpp
index bbf361a..629f37e 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -924,8 +924,9 @@ bool Position::legal(Move m) const {
 
   Bitboard occupied = (type_of(m) != DROP ? pieces() ^ from : pieces()) | to;
 
-  // Flying general rule
-  if (var->flyingGeneral && count<KING>(us))
+  // Flying general rule and bikjang
+  // In case of bikjang passing is allowed
+  if ((var->flyingGeneral && count<KING>(us)) || (st->bikjang && !(type_of(moved_piece(m)) == KING && from == to)))
   {
       Square s = type_of(moved_piece(m)) == KING ? to : square<KING>(us);
       if (attacks_bb(~us, ROOK, s, occupied) & pieces(~us, KING) & ~square_bb(to))
diff --git a/tests/perft.sh b/tests/perft.sh
index 706c823..aba4711 100755
--- a/tests/perft.sh
+++ b/tests/perft.sh
@@ -74,7 +74,7 @@ if [[ $1 == "largeboard" ]]; then
   expect perft.exp courier startpos 4 500337 > /dev/null
   expect perft.exp grand startpos 3 259514 > /dev/null
   expect perft.exp xiangqi startpos 4 3290240 > /dev/null
-  expect perft.exp janggi startpos 4 1075083 > /dev/null
+  expect perft.exp janggi startpos 4 1067293 > /dev/null
   expect perft.exp janggi "fen 1n1kaabn1/cr2N4/5C1c1/p1pNp3p/9/9/P1PbP1P1P/3r1p3/4A4/R1BA1KB1R b - - 0 1" 4 76826 > /dev/null
 fi