Also set e.p. rights on move of Lance

The Lance is intended as Pawn alternative (because of its slim shape),
except in Superchess (where it represents Amazon) and Chu. (In regular
Shogi the Lace is represented by Queen disguised as Lance!) So it would
be logical to also make its double-Pushes set e.p. rights. Except in
Spartan Chess, which has no e.p. capture.

diff --git a/backend.c b/backend.c
index 2c7933e..3e432ae 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -9925,11 +9925,14 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
            }
       }
 
-      if( board[fromY][fromX] == WhiteLance || board[fromY][fromX] == BlackLance ) {
-           if( gameInfo.variant != VariantSuper && gameInfo.variant != VariantShogi )
-               board[EP_STATUS] = EP_PAWN_MOVE; // Lance is Pawn-like in most variants
-      } else
-      if( board[fromY][fromX] == WhitePawn ) {
+      piece = board[fromY][fromX];
+      if( piece == WhiteLance || piece == BlackLance ) {
+           if( gameInfo.variant != VariantSuper && gameInfo.variant != VariantChu ) {
+               if(gameInfo.variant == VariantSpartan) board[EP_STATUS] = EP_PAWN_MOVE; // in Spartan no e.p. rights must be set
+               else piece += WhiteLance - WhitePawn; // Lance is Pawn-like in most variants, so let Pawn code treat it by this kludge
+           }
+      }
+      if( piece == WhitePawn ) {
            if(fromY != toY) // [HGM] Xiangqi sideway Pawn moves should not count as 50-move breakers
               board[EP_STATUS] = EP_PAWN_MOVE;
            if( toY-fromY>=2) {
@@ -9942,7 +9945,7 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
                      board[EP_STATUS] = toX;
           }
       } else
-      if( board[fromY][fromX] == BlackPawn ) {
+      if( piece == BlackPawn ) {
            if(fromY != toY) // [HGM] Xiangqi sideway Pawn moves should not count as 50-move breakers
               board[EP_STATUS] = EP_PAWN_MOVE;
            if( toY-fromY<= -2) {