X-Git-Url: http://winboard.nl/cgi-bin?a=blobdiff_plain;f=backend.c;h=2c7933ede4fbfddd7ed3e127ecbd5345e46b845b;hb=00f49d137feed871220bb1ed4193f86704d20dbf;hp=1c4bddcde20b36628ed565ce5cc850c32a707194;hpb=50b75711089c434a89fcb126a5db86e7eb8246a3;p=xboard.git

diff --git a/backend.c b/backend.c
index 1c4bddc..2c7933e 100644
--- a/backend.c
+++ b/backend.c
@@ -295,6 +295,7 @@ ChessSquare promoSweep = EmptySquare, defaultPromoChoice;
 int promoDefaultAltered;
 int keepInfo = 0; /* [HGM] to protect PGN tags in auto-step game analysis */
 static int initPing = -1;
+int border;       /* [HGM] width of board rim, needed to size seek graph  */
 
 /* States for ics_getting_history */
 #define H_FALSE 0
@@ -847,7 +848,7 @@ InitEngine (ChessProgramState *cps, int n)
     if(cps->tidy == NULL) cps->tidy = (char*) malloc(MSG_SIZ);
     TidyProgramName(cps->program, cps->host, cps->tidy);
     cps->matchWins = 0;
-    ASSIGN(cps->variants, appData.variant);
+    ASSIGN(cps->variants, appData.noChessProgram ? "" : appData.variant);
     cps->analysisSupport = 2; /* detect */
     cps->analyzing = FALSE;
     cps->initDone = FALSE;
@@ -954,7 +955,7 @@ extern Boolean isUCI, hasBook, storeVariant, v1, addToList, useNick;
 static char resetOptions[] =
 	"-reuse -firstIsUCI false -firstHasOwnBookUCI true -firstTimeOdds 1 "
 	"-firstInitString \"" INIT_STRING "\" -firstComputerString \"" COMPUTER_STRING "\" "
-	"-firstFeatures \"\" -firstLogo \"\" -firstAccumulateTC 1 "
+	"-firstFeatures \"\" -firstLogo \"\" -firstAccumulateTC 1 -fd \".\" "
 	"-firstOptions \"\" -firstNPS -1 -fn \"\" -firstScoreAbs false";
 
 void
@@ -1200,6 +1201,11 @@ InitBackEnd1 ()
 	DisplayFatalError(buf, 0, 2);
 	return;
 
+      case VariantNormal:     /* definitely works! */
+	if(strcmp(appData.variant, "normal") && !appData.noChessProgram) { // [HGM] hope this is an engine-defined variant
+	  safeStrCpy(engineVariant, appData.variant, MSG_SIZ);
+	  return;
+	}
       case VariantXiangqi:    /* [HGM] repetition rules not implemented */
       case VariantFairy:      /* [HGM] TestLegality definitely off! */
       case VariantGothic:     /* [HGM] should work */
@@ -1212,7 +1218,6 @@ InitBackEnd1 ()
       case VariantFalcon:     /* [HGM] untested */
       case VariantCrazyhouse: /* holdings not shown, ([HGM] fixed that!)
 			         offboard interposition not understood */
-      case VariantNormal:     /* definitely works! */
       case VariantWildCastle: /* pieces not automatically shuffled */
       case VariantNoCastle:   /* pieces not automatically shuffled */
       case VariantFischeRandom: /* [HGM] works and shuffles pieces */
@@ -2103,14 +2108,14 @@ StringToVariant (char *e)
     int wnum = -1;
     VariantClass v = VariantNormal;
     int i, found = FALSE;
-    char buf[MSG_SIZ];
+    char buf[MSG_SIZ], c;
     int len;
 
     if (!e) return v;
 
     /* [HGM] skip over optional board-size prefixes */
-    if( sscanf(e, "%dx%d_", &i, &i) == 2 ||
-        sscanf(e, "%dx%d+%d_", &i, &i, &i) == 3 ) {
+    if( sscanf(e, "%dx%d_%c", &i, &i, &c) == 3 ||
+        sscanf(e, "%dx%d+%d_%c", &i, &i, &i, &c) == 4 ) {
         while( *e++ != '_');
     }
 
@@ -2120,7 +2125,7 @@ StringToVariant (char *e)
     } else
     for (i=0; i<sizeof(variantNames)/sizeof(char*); i++) {
       if (p = StrCaseStr(e, variantNames[i])) {
-	if(p && i >= VariantShogi && isalpha(p[strlen(variantNames[i])])) continue;
+	if(p && i >= VariantShogi && (p != e || isalpha(p[strlen(variantNames[i])]))) continue;
 	v = (VariantClass) i;
 	found = TRUE;
 	break;
@@ -2716,8 +2721,8 @@ DrawSeekGraph ()
 {
     int i;
     if(!seekGraphUp) return FALSE;
-    h = BOARD_HEIGHT * (squareSize + lineGap) + lineGap;
-    w = BOARD_WIDTH  * (squareSize + lineGap) + lineGap;
+    h = BOARD_HEIGHT * (squareSize + lineGap) + lineGap + 2*border;
+    w = BOARD_WIDTH  * (squareSize + lineGap) + lineGap + 2*border;
 
     DrawSeekBackground(0, 0, w, h);
     DrawSeekAxis(hMargin, h-1-vMargin, w-5, h-1-vMargin);
@@ -5323,6 +5328,7 @@ UploadGameEvent ()
 }
 
 int killX = -1, killY = -1; // [HGM] lion: used for passing e.p. capture square to MakeMove
+int legNr = 1;
 
 void
 CoordsToComputerAlgebraic (int rf, int ff, int rt, int ft, char promoChar, char move[7])
@@ -5680,7 +5686,7 @@ LoadMultiPV (int x, int y, char *buf, int index, int *start, int *end, int pane)
 	}
 	ParsePV(buf+startPV, FALSE, gameMode != AnalyzeMode);
 	*start = startPV; *end = index-1;
-	extendGame = (gameMode == AnalyzeMode && appData.autoExtend);
+	extendGame = (gameMode == AnalyzeMode && appData.autoExtend && origIndex - startPV < 5);
 	return TRUE;
 }
 
@@ -6027,9 +6033,10 @@ InitPosition (int redraw)
     gameInfo.boardHeight   = 8;
     gameInfo.holdingsSize  = 0;
     nrCastlingRights = -1; /* [HGM] Kludge to indicate default should be used */
-    for(i=0; i<BOARD_FILES-2; i++)
+    for(i=0; i<BOARD_FILES-6; i++)
       initialPosition[CASTLING][i] = initialRights[i] = NoRights; /* but no rights yet */
     initialPosition[EP_STATUS] = EP_NONE;
+    initialPosition[TOUCHED_W] = initialPosition[TOUCHED_B] = 0;
     SetCharTable(pieceToChar, "PNBRQ...........Kpnbrq...........k");
     if(startVariant == gameInfo.variant) // [HGM] nicks: enable nicknames in original variant
          SetCharTable(pieceNickName, appData.pieceNickNames);
@@ -6101,7 +6108,7 @@ InitPosition (int redraw)
     case VariantFalcon:
       pieces = FalconArray;
       gameInfo.boardWidth = 10;
-      SetCharTable(pieceToChar, "PNBRQ.............FKpnbrq.............fk");
+      SetCharTable(pieceToChar, "PNBRQ............FKpnbrq............fk");
       break;
     case VariantXiangqi:
       pieces = XiangqiArray;
@@ -6544,7 +6551,7 @@ HasPromotionChoice (int fromX, int fromY, int toX, int toY, char *promoChoice, i
         int p = piece >= BlackPawn ? BLACK_TO_WHITE piece : piece;
         promotionZoneSize = BOARD_HEIGHT/3;
         highestPromotingPiece = (p >= WhiteLion || PieceToChar(piece + 22) == '.') ? WhitePawn : WhiteLion;
-    } else if(gameInfo.variant == VariantShogi || gameInfo.variant == VariantChuChess) {
+    } else if(gameInfo.variant == VariantShogi) {
         promotionZoneSize = BOARD_HEIGHT/3;
         highestPromotingPiece = (int)WhiteAlfil;
     } else if(gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess) {
@@ -6984,7 +6991,7 @@ UserMoveEvent(int fromX, int fromY, int toX, int toY, int promoChar)
 	   // holdings might not be sent yet in ICS play; we have to figure out which piece belongs here
 	   if(fromX == 0) fromY = BOARD_HEIGHT-1 - fromY; // black holdings upside-down
 	   fromX = fromX ? WhitePawn : BlackPawn; // first piece type in selected holdings
-	   while(PieceToChar(fromX) == '.' || PieceToNumber(fromX) != fromY && fromX != (int) EmptySquare) fromX++;
+	   while(PieceToChar(fromX) == '.' || PieceToChar(fromX) == '+' || PieceToNumber(fromX) != fromY && fromX != (int) EmptySquare) fromX++;
          fromY = DROP_RANK;
     }
 
@@ -7257,11 +7264,11 @@ Mark (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VO
 {
     typedef char Markers[BOARD_RANKS][BOARD_FILES];
     Markers *m = (Markers *) closure;
-    if(rf == fromY && ff == fromX && (killX < 0 && !(rt == rf && ft == ff) || abs(ft-killX) < 2 && abs(rt-killY) < 2))
+    if(rf == fromY && ff == fromX && (killX < 0 ? !(rt == rf && ft == ff) && legNr & 1 : rt == killY && ft == killX || legNr & 2))
 	(*m)[rt][ft] = 1 + (board[rt][ft] != EmptySquare
 			 || kind == WhiteCapturesEnPassant
-			 || kind == BlackCapturesEnPassant) + 3*(kind == FirstLeg && killX < 0);
-    else if(flags & F_MANDATORY_CAPTURE && board[rt][ft] != EmptySquare) (*m)[rt][ft] = 3;
+			 || kind == BlackCapturesEnPassant) + 3*(kind == FirstLeg && killX < 0), legal[rt][ft] = 1;
+    else if(flags & F_MANDATORY_CAPTURE && board[rt][ft] != EmptySquare) (*m)[rt][ft] = 3, legal[rt][ft] = 1;
 }
 
 static int hoverSavedValid;
@@ -7277,7 +7284,7 @@ MarkTargetSquares (int clear)
   } else {
     int capt = 0;
     if(!appData.markers || !appData.highlightDragging || appData.icsActive && gameInfo.variant < VariantShogi ||
-       !appData.testLegality || gameMode == EditPosition) return;
+       !appData.testLegality && !pieceDefs || gameMode == EditPosition) return;
     GenLegal(boards[currentMove], PosFlags(currentMove), Mark, (void*) marker, EmptySquare);
     if(PosFlags(0) & F_MANDATORY_CAPTURE) {
       for(x=0; x<BOARD_WIDTH; x++) for(y=0; y<BOARD_HEIGHT; y++) if(marker[y][x]>1) capt++;
@@ -7353,7 +7360,8 @@ void ReportClick(char *action, int x, int y)
 	char buf[MSG_SIZ]; // Inform engine of what user does
 	int r, f;
 	if(action[0] == 'l') // mark any target square of a lifted piece as legal to-square, clear markers
-	  for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) legal[r][f] = 1, marker[r][f] = 0;
+	  for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
+	    legal[r][f] = !pieceDefs || !appData.markers, marker[r][f] = 0;
 	if(!first.highlight || gameMode == EditPosition) return;
 	snprintf(buf, MSG_SIZ, "%s %c%d%s\n", action, x+AAA, y+ONE-'0', controlKey && action[0]=='p' ? "," : "");
 	SendToProgram(buf, &first);
@@ -7574,7 +7582,8 @@ LeftClick (ClickType clickType, int xPix, int yPix)
 
     clearFlag = 0;
 
-    if(gameMode != EditPosition && !appData.testLegality && !legal[y][x] && (x != killX || y != killY) && !sweepSelecting) {
+    if(gameMode != EditPosition && !appData.testLegality && !legal[y][x] &&
+       fromX >= BOARD_LEFT && fromX < BOARD_RGHT && (x != killX || y != killY) && !sweepSelecting) {
 	if(dragging) DragPieceEnd(xPix, yPix), dragging = 0;
 	DisplayMessage(_("only marked squares are legal"),"");
 	DrawPosition(TRUE, NULL);
@@ -8727,7 +8736,7 @@ FakeBookMove: // [HGM] book: we jump here to simulate machine moves after book h
                 if( count & 1 ) {
                     score = -score; /* Flip score for winning side */
                 }
-printf("score=%d count=%d\n",score,count);
+
                 if( score > appData.adjudicateLossThreshold ) {
                     break;
                 }
@@ -8869,7 +8878,6 @@ printf("score=%d count=%d\n",score,count);
         s = 8 + strlen(buf), buf[s-9] = NULLCHAR, SetCharTable(pieceToChar, buf);
         ASSIGN(appData.pieceToCharTable, buf);
       }
-      if(startedFromSetupPosition) return;
       dummy = sscanf(message+s, "%dx%d+%d_%s", &w, &h, &hand, varName);
       if(dummy >= 3) {
         while(message[s] && message[s++] != ' ');
@@ -8879,13 +8887,36 @@ printf("score=%d count=%d\n",score,count);
 	    if(dummy == 4) gameInfo.variant = StringToVariant(varName);     // parent variant
           InitPosition(1); // calls InitDrawingSizes to let new parameters take effect
           if(*buf) SetCharTable(pieceToChar, buf); // do again, for it was spoiled by InitPosition
+          startedFromSetupPosition = FALSE;
         }
       }
+      if(startedFromSetupPosition) return;
       ParseFEN(boards[0], &dummy, message+s, FALSE);
       DrawPosition(TRUE, boards[0]);
+      CopyBoard(initialPosition, boards[0]);
       startedFromSetupPosition = TRUE;
       return;
     }
+    if(sscanf(message, "piece %s %s", buf2, buf1) == 2) {
+      ChessSquare piece = WhitePawn;
+      char *p=buf2;
+      if(*p == '+') piece = CHUPROMOTED WhitePawn, p++;
+      piece += CharToPiece(*p) - WhitePawn;
+      if(cps != &first || appData.testLegality && *engineVariant == NULLCHAR
+      /* always accept definition of  */       && piece != WhiteFalcon && piece != BlackFalcon
+      /* wild-card pieces.            */       && piece != WhiteCobra  && piece != BlackCobra
+      /* For variants we don't have   */       && gameInfo.variant != VariantBerolina
+      /* correct rules for, we cannot */       && gameInfo.variant != VariantCylinder
+      /* enforce legality on our own! */       && gameInfo.variant != VariantUnknown
+                                               && gameInfo.variant != VariantGreat
+                                               && gameInfo.variant != VariantFairy    ) return;
+      if(piece < EmptySquare) {
+        pieceDefs = TRUE;
+        ASSIGN(pieceDesc[piece], buf1);
+        if(isupper(*p) && p[1] == '&') { ASSIGN(pieceDesc[WHITE_TO_BLACK piece], buf1); }
+      }
+      return;
+    }
     /* [HGM] Allow engine to set up a position. Don't ask me why one would
      * want this, I was asked to put it in, and obliged.
      */
@@ -9858,7 +9889,7 @@ ParseGameHistory (char *game)
 void
 ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
 {
-  ChessSquare captured = board[toY][toX], piece, king; int p, oldEP = EP_NONE, berolina = 0;
+  ChessSquare captured = board[toY][toX], piece, king; int p, rookX, oldEP = EP_NONE, berolina = 0;
   int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
 
     /* [HGM] compute & store e.p. status and castling rights for new position */
@@ -9867,6 +9898,7 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
       if(gameInfo.variant == VariantBerolina) berolina = EP_BEROLIN_A;
       oldEP = (signed char)board[EP_STATUS];
       board[EP_STATUS] = EP_NONE;
+      board[EP_FILE] = board[EP_RANK] = 100;
 
   if (fromY == DROP_RANK) {
 	/* must be first */
@@ -9900,7 +9932,8 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
       if( board[fromY][fromX] == 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) {
+           if( toY-fromY>=2) {
+               board[EP_FILE] = (fromX + toX)/2; board[EP_RANK] = toY - 1 | 128*(toY - fromY > 2);
                if(toX>BOARD_LEFT   && board[toY][toX-1] == BlackPawn &&
 			gameInfo.variant != VariantBerolina || toX < fromX)
 	              board[EP_STATUS] = toX | berolina;
@@ -9912,7 +9945,8 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
       if( board[fromY][fromX] == 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) {
+           if( toY-fromY<= -2) {
+               board[EP_FILE] = (fromX + toX)/2; board[EP_RANK] = toY + 1 | 128*(fromY - toY > 2);
                if(toX>BOARD_LEFT   && board[toY][toX-1] == WhitePawn &&
 			gameInfo.variant != VariantBerolina || toX < fromX)
 	              board[EP_STATUS] = toX | berolina;
@@ -9922,6 +9956,11 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
 	   }
        }
 
+       if(fromY == 0) board[TOUCHED_W] |= 1<<fromX; else // new way to keep track of virginity
+       if(fromY == BOARD_HEIGHT-1) board[TOUCHED_B] |= 1<<fromX;
+       if(toY == 0) board[TOUCHED_W] |= 1<<toX; else
+       if(toY == BOARD_HEIGHT-1) board[TOUCHED_B] |= 1<<toX;
+
        for(i=0; i<nrCastlingRights; i++) {
            if(board[CASTLING][i] == fromX && castlingRank[i] == fromY ||
               board[CASTLING][i] == toX   && castlingRank[i] == toY
@@ -9946,6 +9985,7 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
     /* FRC castling assumed when king captures friendly rook. [HGM] or RxK for S-Chess */
     if (board[fromY][fromX] == WhiteKing && board[toY][toX] == WhiteRook ||
         board[fromY][fromX] == WhiteRook && board[toY][toX] == WhiteKing) {
+      board[EP_STATUS] = EP_NONE; // capture was fake!
       board[fromY][fromX] = EmptySquare;
       board[toY][toX] = EmptySquare;
       if((toX > fromX) != (piece == WhiteRook)) {
@@ -9955,6 +9995,7 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
       }
     } else if (board[fromY][fromX] == BlackKing && board[toY][toX] == BlackRook ||
                board[fromY][fromX] == BlackRook && board[toY][toX] == BlackKing) {
+      board[EP_STATUS] = EP_NONE;
       board[fromY][fromX] = EmptySquare;
       board[toY][toX] = EmptySquare;
       if((toX > fromX) != (piece == BlackRook)) {
@@ -9969,15 +10010,17 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
         && toY == fromY && toX > fromX+1) {
 	board[fromY][fromX] = EmptySquare;
         board[toY][toX] = king;
-        board[toY][toX-1] = board[fromY][BOARD_RGHT-1];
-        board[fromY][BOARD_RGHT-1] = EmptySquare;
+	for(rookX=BOARD_RGHT-1; board[toY][rookX] == DarkSquare && rookX > toX + 1; rookX--);
+        board[toY][toX-1] = board[fromY][rookX];
+        board[fromY][rookX] = EmptySquare;
     } else if (board[fromY][fromX] == king
         && fromX != BOARD_LEFT && fromX != BOARD_RGHT-1 // [HGM] cylinder */
                && toY == fromY && toX < fromX-1) {
 	board[fromY][fromX] = EmptySquare;
         board[toY][toX] = king;
-        board[toY][toX+1] = board[fromY][BOARD_LEFT];
-        board[fromY][BOARD_LEFT] = EmptySquare;
+	for(rookX=BOARD_LEFT; board[toY][rookX] == DarkSquare && rookX < toX - 1; rookX++);
+        board[toY][toX+1] = board[fromY][rookX];
+        board[fromY][rookX] = EmptySquare;
     } else if ((board[fromY][fromX] == WhitePawn && gameInfo.variant != VariantXiangqi ||
                 board[fromY][fromX] == WhiteLance && gameInfo.variant != VariantSuper && gameInfo.variant != VariantChu)
                && toY >= BOARD_HEIGHT-promoRank && promoChar // defaulting to Q is done elsewhere
@@ -9988,7 +10031,7 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
             board[toY][toX] = (ChessSquare) (PROMOTED board[toY][toX]);
 	board[fromY][fromX] = EmptySquare;
     } else if ((fromY >= BOARD_HEIGHT>>1)
-	       && (oldEP == toX || oldEP == EP_UNKNOWN || appData.testLegality)
+	       && (oldEP == toX || oldEP == EP_UNKNOWN || appData.testLegality || abs(toX - fromX) > 4)
 	       && (toX != fromX)
                && gameInfo.variant != VariantXiangqi
                && gameInfo.variant != VariantBerolina
@@ -9996,8 +10039,10 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
 	       && (board[toY][toX] == EmptySquare)) {
 	board[fromY][fromX] = EmptySquare;
 	board[toY][toX] = WhitePawn;
-	captured = board[toY - 1][toX];
-	board[toY - 1][toX] = EmptySquare;
+	if(toY == board[EP_RANK] - 128 + 1)
+	    captured = board[toY - 2][toX], board[toY - 2][toX] = EmptySquare;
+	else
+	    captured = board[toY - 1][toX], board[toY - 1][toX] = EmptySquare;
     } else if ((fromY == BOARD_HEIGHT-4)
 	       && (toX == fromX)
                && gameInfo.variant == VariantBerolina
@@ -10016,15 +10061,17 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
                && toY == fromY && toX > fromX+1) {
 	board[fromY][fromX] = EmptySquare;
         board[toY][toX] = king;
-        board[toY][toX-1] = board[fromY][BOARD_RGHT-1];
-        board[fromY][BOARD_RGHT-1] = EmptySquare;
+	for(rookX=BOARD_RGHT-1; board[toY][rookX] == DarkSquare && rookX > toX + 1; rookX--);
+        board[toY][toX-1] = board[fromY][rookX];
+        board[fromY][rookX] = EmptySquare;
     } else if (board[fromY][fromX] == king
         && fromX != BOARD_LEFT && fromX != BOARD_RGHT-1 // [HGM] cylinder */
                && toY == fromY && toX < fromX-1) {
 	board[fromY][fromX] = EmptySquare;
         board[toY][toX] = king;
-        board[toY][toX+1] = board[fromY][BOARD_LEFT];
-        board[fromY][BOARD_LEFT] = EmptySquare;
+	for(rookX=BOARD_LEFT; board[toY][rookX] == DarkSquare && rookX < toX - 1; rookX++);
+        board[toY][toX+1] = board[fromY][rookX];
+        board[fromY][rookX] = EmptySquare;
     } else if (fromY == 7 && fromX == 3
 	       && board[fromY][fromX] == BlackKing
 	       && toY == 7 && toX == 5) {
@@ -10049,7 +10096,7 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
             board[toY][toX] = (ChessSquare) (PROMOTED board[toY][toX]);
 	board[fromY][fromX] = EmptySquare;
     } else if ((fromY < BOARD_HEIGHT>>1)
-	       && (oldEP == toX || oldEP == EP_UNKNOWN || appData.testLegality)
+	       && (oldEP == toX || oldEP == EP_UNKNOWN || appData.testLegality || abs(toX - fromX) > 4)
 	       && (toX != fromX)
                && gameInfo.variant != VariantXiangqi
                && gameInfo.variant != VariantBerolina
@@ -10057,8 +10104,10 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
 	       && (board[toY][toX] == EmptySquare)) {
 	board[fromY][fromX] = EmptySquare;
 	board[toY][toX] = BlackPawn;
-	captured = board[toY + 1][toX];
-	board[toY + 1][toX] = EmptySquare;
+	if(toY == board[EP_RANK] - 128 - 1)
+	    captured = board[toY + 2][toX], board[toY + 2][toX] = EmptySquare;
+	else
+	    captured = board[toY + 1][toX], board[toY + 1][toX] = EmptySquare;
     } else if ((fromY == 3)
 	       && (toX == fromX)
                && gameInfo.variant == VariantBerolina
@@ -10118,8 +10167,8 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
         p = (int) captured;
         if (p >= (int) BlackPawn) {
           p -= (int)BlackPawn;
-          if(gameInfo.variant == VariantShogi && DEMOTED p >= 0) {
-                  /* in Shogi restore piece to its original  first */
+          if(DEMOTED p >= 0 && PieceToChar(p) == '+') {
+                  /* Restore shogi-promoted piece to its original  first */
                   captured = (ChessSquare) (DEMOTED captured);
                   p = DEMOTED p;
           }
@@ -10129,7 +10178,7 @@ ApplyMove (int fromX, int fromY, int toX, int toY, int promoChar, Board board)
           board[p][BOARD_WIDTH-1] = BLACK_TO_WHITE captured;
 	} else {
           p -= (int)WhitePawn;
-          if(gameInfo.variant == VariantShogi && DEMOTED p >= 0) {
+          if(DEMOTED p >= 0 && PieceToChar(p) == '+') {
                   captured = (ChessSquare) (DEMOTED captured);
                   p = DEMOTED p;
           }
@@ -10457,7 +10506,19 @@ InitChessProgram (ChessProgramState *cps, int setup)
       b = SupportedVariant(cps->variants, gameInfo.variant, gameInfo.boardWidth,
                            gameInfo.boardHeight, gameInfo.holdingsSize, cps->protocolVersion, cps->tidy);
       if (b == NULL) {
-	DisplayFatalError(variantError, 0, 1);
+	VariantClass v;
+	char c, *q = cps->variants, *p = strchr(q, ',');
+	if(p) *p = NULLCHAR;
+	v = StringToVariant(q);
+	DisplayError(variantError, 0);
+	if(v != VariantUnknown && cps == &first) {
+	    int w, h, s;
+	    if(sscanf(q, "%dx%d+%d_%c", &w, &h, &s, &c) == 4) // get size overrides the engine needs with it (if any)
+		appData.NrFiles = w, appData.NrRanks = h, appData.holdingsSize = s, q = strchr(q, '_') + 1;
+	    ASSIGN(appData.variant, q);
+	    Reset(TRUE, FALSE);
+	}
+	if(p) *p = ',';
 	return;
       }
 
@@ -11607,6 +11668,8 @@ Reset (int redraw, int init)
 	fprintf(debugFP, "Reset(%d, %d) from gameMode %d\n",
 		redraw, init, gameMode);
     }
+    pieceDefs = FALSE; // [HGM] gen: reset engine-defined piece moves
+    for(i=0; i<EmptySquare; i++) { FREE(pieceDesc[i]); pieceDesc[i] = NULL; }
     CleanupTail(); // [HGM] vari: delete any stored variations
     CommentPopDown(); // [HGM] make sure no comments to the previous game keep hanging on
     pausing = pauseExamInvalid = FALSE;
@@ -12803,7 +12866,7 @@ LoadGame (FILE *f, int gameNumber, char *title, int useList)
 	if (!err) numPGNTags++;
 
         /* [HGM] PGNvariant: automatically switch to variant given in PGN tag */
-        if(gameInfo.variant != oldVariant) {
+        if(gameInfo.variant != oldVariant && (gameInfo.variant != VariantNormal || gameInfo.variantName == NULL || *gameInfo.variantName == NULLCHAR)) {
             startedFromPositionFile = FALSE; /* [HGM] loadPos: variant switch likely makes position invalid */
 	    ResetFrontEnd(); // [HGM] might need other bitmaps. Cannot use Reset() because it clears gameInfo :-(
 	    InitPosition(TRUE);
@@ -12822,6 +12885,8 @@ LoadGame (FILE *f, int gameNumber, char *title, int useList)
 	    return FALSE;
 	  }
 	  CopyBoard(boards[0], initial_position);
+	  if(*engineVariant) // [HGM] for now, assume FEN in engine-defined variant game is default initial position
+	    CopyBoard(initialPosition, initial_position);
 	  if (blackPlaysFirst) {
 	    currentMove = forwardMostMove = backwardMostMove = 1;
 	    CopyBoard(boards[1], initial_position);
@@ -14614,8 +14679,10 @@ TwoMachinesEvent P((void))
 
     if(!SupportedVariant(second.variants, gameInfo.variant, gameInfo.boardWidth,
                          gameInfo.boardHeight, gameInfo.holdingsSize, second.protocolVersion, second.tidy)) {
-	startingEngine = FALSE;
+	startingEngine = matchMode = FALSE;
 	DisplayError("second engine does not play this", 0);
+	gameMode = TwoMachinesPlay; ModeHighlight(); // Needed to make sure menu item is unchecked
+	EditGameEvent(); // switch back to EditGame mode
 	return;
     }
 
@@ -15022,6 +15089,8 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
 
     switch (selection) {
       case ClearBoard:
+	fromX = fromY = killX = killY = -1; // [HGM] abort any move entry in progress
+	MarkTargetSquares(1);
 	CopyBoard(currentBoard, boards[0]);
 	CopyBoard(menuBoard, initialPosition);
 	if (gameMode == IcsExamining && ics_type == ICS_FICS) {
@@ -15473,6 +15542,7 @@ ForwardInner (int target)
 
     seekGraphUp = FALSE;
     MarkTargetSquares(1);
+    fromX = fromY = killX = killY = -1; // [HGM] abort any move entry in progress
 
     if (gameMode == PlayFromGameFile && !pausing)
       PauseEvent();
@@ -15591,6 +15661,7 @@ BackwardInner (int target)
     if (gameMode == EditPosition) return;
     seekGraphUp = FALSE;
     MarkTargetSquares(1);
+    fromX = fromY = killX = killY = -1; // [HGM] abort any move entry in progress
     if (currentMove <= backwardMostMove) {
 	ClearHighlights();
 	DrawPosition(full_redraw, boards[currentMove]);
@@ -16608,6 +16679,10 @@ EngineDefinedVariant (ChessProgramState *cps, int n)
       v = StringToVariant(s);
       if(v == VariantNormal && strcmp(s, "normal") && !strstr(s, "_normal")) v = VariantUnknown; // garbage is recognized as normal
 	if(v == VariantUnknown) { // non-standard variant in list of engine-supported variants
+	    if(!strcmp(s, "tenjiku") || !strcmp(s, "dai") || !strcmp(s, "dada") || // ignore Alien-Edition variants
+	       !strcmp(s, "maka") || !strcmp(s, "tai") || !strcmp(s, "kyoku") ||
+	       !strcmp(s, "checkers") || !strcmp(s, "go") || !strcmp(s, "reversi") ||
+	       !strcmp(s, "dark") || !strcmp(s, "alien") || !strcmp(s, "multi") || !strcmp(s, "amazons") ) n++;
 	    if(--n < 0) safeStrCpy(buf, s, MSG_SIZ);
 	}
 	if(p) *p++ = ',';
@@ -17766,8 +17841,17 @@ 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   )
@@ -17775,12 +17859,18 @@ 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 */
@@ -17790,9 +17880,8 @@ 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
-                for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q && j; i--)
+            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; i--)
                     if((boards[move][0][i] != WhiteKing || k+q == 0) &&
                         boards[move][VIRGIN][i] & VIRGIN_W) *p++ = i + AAA + 'A' - 'a';
             }
@@ -17802,9 +17891,8 @@ 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
-                for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q && j; i--)
+            if(handB) {
+                for(i=BOARD_RGHT-1-k; i>=BOARD_LEFT+q; i--)
                     if((boards[move][BOARD_HEIGHT-1][i] != BlackKing || k+q == 0) &&
                         boards[move][VIRGIN][i] & VIRGIN_B) *p++ = i + AAA;
             }