From 7a9e8a6260d9b6be62e80f2250d211f30a1e50fb Mon Sep 17 00:00:00 2001
From: H.G.Muller <hgm@hgm-xboard.(none)>
Date: Wed, 8 Oct 2014 18:28:09 +0200
Subject: [PATCH] Fix writing of Seirawan960 virginity in FEN

When variant seirawan was played with Fischer castling, only the
castling rights were written, and not the virginity of other pieces.
Now all virgin files are dumped in Shredder-FEN style.
---
 backend.c |   21 +++++++++++++++++----
 1 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/backend.c b/backend.c
index b248d03..315bd8e 100644
--- a/backend.c
+++ b/backend.c
@@ -17817,8 +17817,17 @@ PositionToFEN (int move, char *overrideCastling, int moveCounts)
     while(*p++ = *q++); if(q != overrideCastling+1) p[-1] = ' '; else --p;
   } else {
   if(nrCastlingRights) {
+     int handW=0, handB=0;
+     if(gameInfo.variant == VariantSChess) { // for S-Chess, all virgin backrank pieces must be listed
+	for(i=0; i<BOARD_HEIGHT; i++) handW += boards[move][i][BOARD_RGHT]; // count white held pieces
+	for(i=0; i<BOARD_HEIGHT; i++) handB += boards[move][i][BOARD_LEFT-1]; // count black held pieces
+     }
      q = p;
      if(appData.fischerCastling) {
+	if(handW) { // in shuffle S-Chess simply dump all virgin pieces
+           for(i=BOARD_RGHT-1; i>=BOARD_LEFT; i--)
+               if(boards[move][VIRGIN][i] & VIRGIN_W) *p++ = i + AAA + 'A' - 'a';
+	} else {
        /* [HGM] write directly from rights */
            if(boards[move][CASTLING][2] != NoRights &&
               boards[move][CASTLING][0] != NoRights   )
@@ -17826,12 +17835,18 @@ PositionToFEN (int move, char *overrideCastling, int moveCounts)
            if(boards[move][CASTLING][2] != NoRights &&
               boards[move][CASTLING][1] != NoRights   )
                 *p++ = boards[move][CASTLING][1] + AAA + 'A' - 'a';
+	}
+	if(handB) {
+           for(i=BOARD_RGHT-1; i>=BOARD_LEFT; i--)
+               if(boards[move][VIRGIN][i] & VIRGIN_B) *p++ = i + AAA;
+	} else {
            if(boards[move][CASTLING][5] != NoRights &&
               boards[move][CASTLING][3] != NoRights   )
                 *p++ = boards[move][CASTLING][3] + AAA;
            if(boards[move][CASTLING][5] != NoRights &&
               boards[move][CASTLING][4] != NoRights   )
                 *p++ = boards[move][CASTLING][4] + AAA;
+	}
      } else {
 
         /* [HGM] write true castling rights */
@@ -17841,8 +17856,7 @@ PositionToFEN (int move, char *overrideCastling, int moveCounts)
                boards[move][CASTLING][2] != NoRights  ) k = 1, *p++ = 'K';
             q = (boards[move][CASTLING][1] == BOARD_LEFT &&
                  boards[move][CASTLING][2] != NoRights  );
-            if(gameInfo.variant == VariantSChess) { // for S-Chess, indicate all vrgin backrank pieces
-		for(i=j=0; i<BOARD_HEIGHT; i++) j += boards[move][i][BOARD_RGHT]; // count white held pieces
+            if(handW) { // for S-Chess with pieces in hand, list virgin pieces between K and Q
                 for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q && j; i--)
                     if((boards[move][0][i] != WhiteKing || k+q == 0) &&
                         boards[move][VIRGIN][i] & VIRGIN_W) *p++ = i + AAA + 'A' - 'a';
@@ -17853,8 +17867,7 @@ PositionToFEN (int move, char *overrideCastling, int moveCounts)
                boards[move][CASTLING][5] != NoRights  ) k = 1, *p++ = 'k';
             q = (boards[move][CASTLING][4] == BOARD_LEFT &&
                  boards[move][CASTLING][5] != NoRights  );
-            if(gameInfo.variant == VariantSChess) {
-		for(i=j=0; i<BOARD_HEIGHT; i++) j += boards[move][i][BOARD_LEFT-1]; // count black held pieces
+            if(handB) {
                 for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q && j; i--)
                     if((boards[move][BOARD_HEIGHT-1][i] != BlackKing || k+q == 0) &&
                         boards[move][VIRGIN][i] & VIRGIN_B) *p++ = i + AAA;
-- 
1.7.0.4