From ab773ff40f992d0462d500b429d4df863be9d288 Mon Sep 17 00:00:00 2001
From: H.G.Muller <hgm@hgm-xboard.(none)>
Date: Thu, 22 Dec 2016 21:22:28 +0100
Subject: [PATCH] Correct promotion zone for blacked-out ranks

When the window height has to be larger than the board height, to accomodate
the holdings (as in Wa Shogi), this is done by defining the board height as
large as the holdings size, and blacking out the extra ranks. But when the
depth is calculated as 1/3 of the board height, it should use the real
board height, not the artificially enlarged one.
---
 backend.c |   21 +++++++++++----------
 1 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/backend.c b/backend.c
index 805ff05..933b07a 100644
--- a/backend.c
+++ b/backend.c
@@ -6712,12 +6712,13 @@ HasPromotionChoice (int fromX, int fromY, int toX, int toY, char *promoChoice, i
 
     piece = boards[currentMove][fromY][fromX];
     if(gameInfo.variant == VariantChu) {
-        promotionZoneSize = BOARD_HEIGHT/3;
+        promotionZoneSize = (BOARD_HEIGHT - deadRanks)/3;
         if(legal[toY][toX] == 6) return FALSE; // no promotion if highlights deny it
         highestPromotingPiece = (PieceToChar(piece) == '+' || PieceToChar(CHUPROMOTED(piece)) != '+') ? WhitePawn : WhiteKing;
     } else if(gameInfo.variant == VariantShogi) {
-        promotionZoneSize = BOARD_HEIGHT/3 +(BOARD_HEIGHT == 8);
+        promotionZoneSize = (BOARD_HEIGHT- deadRanks)/3 +(BOARD_HEIGHT == 8);
         highestPromotingPiece = (int)WhiteAlfil;
+        if(PieceToChar(piece) != '+' || PieceToChar(CHUPROMOTED(piece)) == '+') highestPromotingPiece = piece;
     } else if(gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess) {
         promotionZoneSize = 3;
     }
@@ -6735,9 +6736,9 @@ HasPromotionChoice (int fromX, int fromY, int toX, int toY, char *promoChoice, i
         if(fromY < promotionZoneSize && gameInfo.variant == VariantChuChess) return FALSE;
         highestPromotingPiece = WHITE_TO_BLACK highestPromotingPiece;
     } else {
-        if(  toY < BOARD_HEIGHT - promotionZoneSize &&
-           fromY < BOARD_HEIGHT - promotionZoneSize) return FALSE;
-        if(fromY >= BOARD_HEIGHT - promotionZoneSize && gameInfo.variant == VariantChuChess)
+        if(  toY < BOARD_HEIGHT - deadRanks - promotionZoneSize &&
+           fromY < BOARD_HEIGHT - deadRanks - promotionZoneSize) return FALSE;
+        if(fromY >= BOARD_HEIGHT - deadRanks - promotionZoneSize && gameInfo.variant == VariantChuChess)
              return FALSE;
     }
 
@@ -6753,9 +6754,9 @@ HasPromotionChoice (int fromX, int fromY, int toX, int toY, char *promoChoice, i
 		return FALSE;
 	    }
 	} else {
-	    if(toY == BOARD_HEIGHT-1 && piece == WhitePawn ||
-	       toY == BOARD_HEIGHT-1 && piece == WhiteQueen ||
-	       toY >= BOARD_HEIGHT-2 && piece == WhiteKnight) {
+	    if(toY == BOARD_HEIGHT-deadRanks-1 && piece == WhitePawn ||
+	       toY == BOARD_HEIGHT-deadRanks-1 && piece == WhiteQueen ||
+	       toY >= BOARD_HEIGHT-deadRanks-2 && piece == WhiteKnight) {
 		*promoChoice = '+';
 		return FALSE;
 	    }
@@ -7500,9 +7501,9 @@ CanPromote (ChessSquare piece, int y)
 	  (gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
            gameInfo.variant == VariantMakruk) && !*engineVariant) return FALSE;
 	return (piece == BlackPawn && y <= zone ||
-		piece == WhitePawn && y >= BOARD_HEIGHT-1-zone ||
+		piece == WhitePawn && y >= BOARD_HEIGHT-1-deadRanks-zone ||
 		piece == BlackLance && y <= zone ||
-		piece == WhiteLance && y >= BOARD_HEIGHT-1-zone );
+		piece == WhiteLance && y >= BOARD_HEIGHT-1-deadRanks-zone );
 }
 
 void
-- 
1.7.0.4