From c9b6cf0a2531f5b27357412aacf032c7969ae8c0 Mon Sep 17 00:00:00 2001
From: H.G.Muller <hgm@hgm-xboard.(none)>
Date: Thu, 7 Apr 2016 19:34:20 +0200
Subject: [PATCH] Finish castling and e.p. rights for Edit Position

In stead of faking rights based on corner positioning of Rooks and
e-file King, EditPositionDone now interprets the rightsBoard that
recorded 'promotion clicks' on King, Rooks or Pawns to toggle their
rights. This rightsBoard is initialized from the castling rights in
the position that is being edited, and the clear and piece-pallette
boards now also set these castling rights correctly.
---
 backend.c |   43 ++++++++++++++++++++++++-------------------
 1 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/backend.c b/backend.c
index 0223dfb..ac29d58 100644
--- a/backend.c
+++ b/backend.c
@@ -7112,14 +7112,13 @@ UserMoveEvent (int fromX, int fromY, int toX, int toY, int promoChar)
 		ChessSquare p = boards[0][rf][ff];
 		if(PieceToChar(p) == '+') gatingPiece = CHUDEMOTED(p); else
 		if(PieceToChar(CHUPROMOTED(p)) =='+') gatingPiece = CHUPROMOTED(p); else
-		if(p == WhiteKing || p == BlackKing || p == WhiteRook || p == BlackRook) {
+		if(p == WhiteKing || p == BlackKing || p == WhiteRook || p == BlackRook || p == WhitePawn || p == BlackPawn) {
 		    int n = rightsBoard[toY][toX] ^= 1; // toggle virginity of K or R
 		    DisplayMessage("", n ? _("rights granted") : _("rights revoked"));
 		    gatingPiece = p;
 		}
-	    }
+	    } else  rightsBoard[toY][toX] = 0;  // revoke rights on moving
 	    boards[0][toY][toX] = boards[0][fromY][fromX];
-	    rightsBoard[toY][toX] = 0;  // revoke rights on moving
 	    if(fromX == BOARD_LEFT-2) { // handle 'moves' out of holdings
 		if(boards[0][fromY][0] != EmptySquare) {
 		    if(boards[0][fromY][1]) boards[0][fromY][1]--;
@@ -15353,22 +15352,23 @@ EditPositionDone (Boolean fakeRights)
     startedFromSetupPosition = TRUE;
     InitChessProgram(&first, FALSE);
     if(fakeRights) { // [HGM] suppress this if we just pasted a FEN.
+      int r, f;
       boards[0][EP_STATUS] = EP_NONE;
-      boards[0][CASTLING][2] = boards[0][CASTLING][5] = BOARD_WIDTH>>1;
-      if(boards[0][0][BOARD_WIDTH>>1] == king) {
-	boards[0][CASTLING][1] = boards[0][0][BOARD_LEFT] == WhiteRook ? BOARD_LEFT : NoRights;
-	boards[0][CASTLING][0] = boards[0][0][BOARD_RGHT-1] == WhiteRook ? BOARD_RGHT-1 : NoRights;
-      } else boards[0][CASTLING][2] = NoRights;
-      if(boards[0][BOARD_HEIGHT-1][BOARD_WIDTH>>1] == WHITE_TO_BLACK king) {
-	boards[0][CASTLING][4] = boards[0][BOARD_HEIGHT-1][BOARD_LEFT] == BlackRook ? BOARD_LEFT : NoRights;
-	boards[0][CASTLING][3] = boards[0][BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook ? BOARD_RGHT-1 : NoRights;
-      } else boards[0][CASTLING][5] = NoRights;
-      if(gameInfo.variant == VariantSChess) {
-	int i;
-	for(i=BOARD_LEFT; i<BOARD_RGHT; i++) { // pieces in their original position are assumed virgin
-	  boards[0][VIRGIN][i] = 0;
-	  if(boards[0][0][i]              == FIDEArray[0][i-BOARD_LEFT]) boards[0][VIRGIN][i] |= VIRGIN_W;
-	  if(boards[0][BOARD_HEIGHT-1][i] == FIDEArray[1][i-BOARD_LEFT]) boards[0][VIRGIN][i] |= VIRGIN_B;
+      for(f=0; f<=nrCastlingRights; f++) boards[0][CASTLING][f] = NoRights;
+      for(r=BOARD_HEIGHT-1; r>=0; r--) for(f=BOARD_RGHT-1; f>=BOARD_LEFT; f--) { // first pass: Kings & e.p.
+	if(rightsBoard[r][f]) {
+	  ChessSquare p = boards[0][r][f];
+	  if(p == (blackPlaysFirst ? WhitePawn : BlackPawn)) boards[0][EP_STATUS] = f;
+	  else if(p == king) boards[0][CASTLING][2] = f;
+	  else if(p == WHITE_TO_BLACK king) boards[0][CASTLING][5] = f;
+	  else rightsBoard[r][f] = 2; // mark for second pass
+	}
+      }
+      for(r=BOARD_HEIGHT-1; r>=0; r--) for(f=BOARD_RGHT-1; f>=BOARD_LEFT; f--) { // second pass: Rooks
+	if(rightsBoard[r][f] == 2) {
+	  ChessSquare p = boards[0][r][f];
+	  if(p == WhiteRook) boards[0][CASTLING][(f < boards[0][CASTLING][2])] = f; else
+	  if(p == BlackRook) boards[0][CASTLING][(f < boards[0][CASTLING][5])+3] = f;
 	}
       }
     }
@@ -15500,14 +15500,16 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
 		    }
 		}
 	    }
+	    CopyBoard(rightsBoard, nullBoard);
 	    if(gameMode != IcsExamining) { // [HGM] editpos: cycle trough boards
-		int r;
+		int r, i;
 		for(r = 0; r < BOARD_HEIGHT; r++) {
 		  for(x = BOARD_LEFT; x < BOARD_RGHT; x++) { // create 'menu board' by removing duplicates 
 		    ChessSquare p = menuBoard[r][x];
 		    for(y = x + 1; y < BOARD_RGHT; y++) if(menuBoard[r][y] == p) menuBoard[r][y] = EmptySquare;
 		  }
 		}
+		menuBoard[CASTLING][0] = menuBoard[CASTLING][3] = NoRights; // h-side Rook was deleted
 		DisplayMessage("Clicking clock again restores position", "");
 		if(gameInfo.variant != lastVariant) lastVariant = gameInfo.variant, CopyBoard(erasedBoard, boards[0]);
 		if(!nonEmpty) { // asked to clear an empty board
@@ -15522,6 +15524,8 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
 		} else
 		    CopyBoard(erasedBoard, currentBoard);
 
+		for(i=0; i<nrCastlingRights; i++) if(boards[0][CASTLING][i] != NoRights)
+		    rightsBoard[castlingRank[i]][boards[0][CASTLING][i]] = 1; // copy remaining rights
 	    }
 	}
 	if (gameMode == EditPosition) {
@@ -15588,6 +15592,7 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
         baseRank = 0;
       case BlackRook:
         if(y == baseRank && (x == BOARD_LEFT || x == BOARD_RGHT-1 || appData.fischerCastling)) hasRights = 1;
+        if(y == baseRank && (x == BOARD_WIDTH>>1 || appData.fischerCastling)) hasRights = 1;
         goto defaultlabel;
 
       case WhiteKing:
-- 
1.7.0.4