Fix multi-leg promotions

Two-leg promotions were sent as gibberish to the engine (and thus
rejected). It was also pretty annoying that XBoard's own idea of
what should be promotions was still applied even when highlighting
denied promotions (because the zone was different than assumed, or
a promotion-on-entry rule applies). Now the legality markers from
the GUI move generator are different from the red and yellow markers
from an engine highlight command, and the latter are taken as a denial
of promotion, and will suppress it.

diff --git a/backend.c b/backend.c
index 241bf96..79d04fb 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -5169,7 +5169,7 @@ SendMoveToProgram (int moveNum, ChessProgramState *cps)
                                               m[2], m[3] - '0',
                                               m[5], m[6] - '0',
                                               m[2] + (m[0] > m[5] ? 1 : -1), m[3] - '0');
-       else if(*c && m[8]) { // kill square followed by 2 characters: 2nd kill square rather than promo suffix
+       else if(*c && m[8] != '\n') { // kill square followed by 2 characters: 2nd kill square rather than promo suffix
          *c = m[9]; if(*c == '\n') *c = NULLCHAR;
          snprintf(buf, MSG_SIZ, "%c%d%c%d,%c%d%c%d,%c%d%c%d%s\n", m[0], m[1] - '0', // convert to three moves
                                               m[7], m[8] - '0',
@@ -5386,7 +5386,7 @@ CoordsToComputerAlgebraic (int rf, int ff, int rt, int ft, char promoChar, char
            sprintf(move, "%c%c%c%c%c\n",
                     AAA + ff, ONE + rf, AAA + ft, ONE + rt, promoChar);
          if(killX >= 0 && killY >= 0) {
-           sprintf(move+4, ";%c%c\n", AAA + killX, ONE + killY);
+           sprintf(move+4, ";%c%c%c\n", AAA + killX, ONE + killY, promoChar);
            if(kill2X >= 0 && kill2Y >= 0) sprintf(move+7, "%c%c%c\n", AAA + kill2X, ONE + kill2Y, promoChar);
          }
        }
@@ -6707,6 +6707,7 @@ 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;
+        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);
@@ -7405,7 +7406,7 @@ MarkByFEN(char *fen)
            int s = 0;
            if(*fen == 'M') legal[r][f] = 2; else // request promotion choice
            if(*fen == 'B') legal[r][f] = 4; else // request auto-promotion to victim
-           if(*fen >= 'A' && *fen <= 'Z') legal[r][f] = 3; else
+           if(*fen >= 'A' && *fen <= 'Z') legal[r][f] = 6; else
            if(*fen >= 'a' && *fen <= 'z') *fen += 'A' - 'a';
            if(*fen == '/' && f > BOARD_LEFT) f = BOARD_LEFT, r--; else
            if(*fen == 'T') marker[r][f++] = 0; else