Fix packing of FRC castlings

The routine for packing moves to the internal database format was not
working for FRC castlings, totally messing up position search for FRC
and CRC.

diff --git a/backend.c b/backend.c
index 585144d..1ba1fbe 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -11722,22 +11722,40 @@ void
 PackMove (int fromX, int fromY, int toX, int toY, ChessSquare promoPiece)
 {
     int sq = fromX + (fromY<<4);
-    int piece = quickBoard[sq];
+    int piece = quickBoard[sq], rook;
     quickBoard[sq] = 0;
     moveDatabase[movePtr].to = pieceList[piece] = sq = toX + (toY<<4);
-    if(piece == pieceList[1] && fromY == toY && (toX > fromX+1 || toX < fromX-1) && fromX != BOARD_LEFT && fromX != BOARD_RGHT-1) {
+    if(piece == pieceList[1] && fromY == toY) {
+      if((toX > fromX+1 || toX < fromX-1) && fromX != BOARD_LEFT && fromX != BOARD_RGHT-1) {
        int from = toX>fromX ? BOARD_RGHT-1 : BOARD_LEFT;
        moveDatabase[movePtr++].piece = Q_WCASTL;
        quickBoard[sq] = piece;
        piece = quickBoard[from]; quickBoard[from] = 0;
        moveDatabase[movePtr].to = pieceList[piece] = sq = toX>fromX ? sq-1 : sq+1;
+      } else if((rook = quickBoard[sq]) && pieceType[rook] == WhiteRook) { // FRC castling
+       quickBoard[sq] = 0; // remove Rook
+       moveDatabase[movePtr].to = sq = (toX>fromX ? BOARD_RGHT-2 : BOARD_LEFT+2); // King to-square
+       moveDatabase[movePtr++].piece = Q_WCASTL;
+       quickBoard[sq] = pieceList[1]; // put King
+       piece = rook;
+       moveDatabase[movePtr].to = pieceList[rook] = sq = toX>fromX ? sq-1 : sq+1;
+      }
     } else
-    if(piece == pieceList[2] && fromY == toY && (toX > fromX+1 || toX < fromX-1) && fromX != BOARD_LEFT && fromX != BOARD_RGHT-1) {
+    if(piece == pieceList[2] && fromY == toY) {
+      if((toX > fromX+1 || toX < fromX-1) && fromX != BOARD_LEFT && fromX != BOARD_RGHT-1) {
        int from = (toX>fromX ? BOARD_RGHT-1 : BOARD_LEFT) + (BOARD_HEIGHT-1 <<4);
        moveDatabase[movePtr++].piece = Q_BCASTL;
        quickBoard[sq] = piece;
        piece = quickBoard[from]; quickBoard[from] = 0;
        moveDatabase[movePtr].to = pieceList[piece] = sq = toX>fromX ? sq-1 : sq+1;
+      } else if((rook = quickBoard[sq]) && pieceType[rook] == BlackRook) { // FRC castling
+       quickBoard[sq] = 0; // remove Rook
+       moveDatabase[movePtr].to = sq = (toX>fromX ? BOARD_RGHT-2 : BOARD_LEFT+2);
+       moveDatabase[movePtr++].piece = Q_BCASTL;
+       quickBoard[sq] = pieceList[2]; // put King
+       piece = rook;
+       moveDatabase[movePtr].to = pieceList[rook] = sq = toX>fromX ? sq-1 : sq+1;
+      }
     } else
     if(epOK && (pieceType[piece] == WhitePawn || pieceType[piece] == BlackPawn) && fromX != toX && quickBoard[sq] == 0) {
        quickBoard[(fromY<<4)+toX] = 0;