Check validity of promotion piece in long algebraic

[capablanca.git] / lasker-2.2.3 / src / movecheck.c

diff --git a/lasker-2.2.3/src/movecheck.c b/lasker-2.2.3/src/movecheck.c
index a2cb8c9..6d05050 100644 (file)
--- a/lasker-2.2.3/src/movecheck.c
+++ b/lasker-2.2.3/src/movecheck.c
@@ -1665,6 +1665,28 @@ static int move_calculate(struct game_state_t * gs, struct move_t * mt, int prom
     // non-promotion can still be an option for deeper promotion zones
     mt->piecePromotionTo = promote ? (promote | stm) : NOPIECE;
     if(promote && gs->promoType == 2 && !gs->holding[stm == BLACK][promote-1]) return MOVE_ILLEGAL; // unavailable piece specified
+    if(promote == KNIGHT && gs->royalKnight) return MOVE_ILLEGAL; // Knight not allowed in Knightmate
+    if(gs->promoType != 2 && promote > QUEEN) { // for promoType != 2 we must check explicitly if the requested pieceis compatible with the variant
+       switch(promote) {
+         case HAWK:
+         case SELEPHANT:
+           if(gs->drops != 2) return MOVE_ILLEGAL; // allowed only in S-Chess
+           break;
+         case MARSHALL:
+         case CARDINAL:
+           if(!gs->capablancaPieces) return MOVE_ILLEGAL; // allowed when flagged so
+           break;
+         case FERZ:
+         case FERZ2:
+           if(!gs->pawnDblStep) return MOVE_ILLEGAL; // allowed in Shatranj and Courier
+           break;
+         case MAN2:
+           if(!gs->royalKnight) return MOVE_ILLEGAL; // allowed only in Knightmate
+           break;
+         default:
+           return MOVE_ILLEGAL;
+       }
+    }
   } else
   if ((piecetype(gs->board[mt->fromFile][mt->fromRank]) == HOPLITE) && 
       ((mt->toRank < gs->promoZone) || (mt->toRank >= gs->ranks - gs->promoZone))) {