Fix Seirawan gating at Rook square in PGN castling moves

[xboard.git] / parser.c

diff --git a/parser.c b/parser.c
index 0938242..797a40c 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -642,9 +642,12 @@ badMove:// we failed to find algebraic move
                    Match("OO", p) || Match("oo", p) || Match("00", p)) castlingType = 1;
            if(castlingType) { //code from old parser, collapsed for both castling types, and streamlined a bit
                int rf, ff, rt, ft; ChessSquare king;
-               char promo=NULLCHAR;
+               char promo=NULLCHAR, gate = 0;
 
-               if(gameInfo.variant == VariantSChess) promo = PromoSuffix(p);
+               if(gameInfo.variant == VariantSChess) {
+                   promo = PromoSuffix(p);
+                   if(promo && **p >= 'a' && **p < AAA + BOARD_RGHT) gate = *(*p)++;
+               }
 
                if (yyskipmoves) return (int) AmbiguousMove; /* not disambiguated */
 
@@ -680,6 +683,12 @@ badMove:// we failed to find algebraic move
                    if (appData.debugMode) fprintf(debugFP, "Parser FRC (type=%d) %d %d\n", castlingType, ff, ft);
                    if(ff == NoRights || ft == NoRights) return ImpossibleMove;
                }
+               if(gate) { // gating disambiguator present
+                   if(gate != ff + AAA) {
+                       int h = ft; ft = ff; ff = h; // reverse for gating at Rook square
+                       if(gate != AAA + initialRights[castlingType+(wom?-1:2)]) return ImpossibleMove;
+                   }
+               }
                sprintf(currentMoveString, "%c%c%c%c%c",ff+AAA,rf+ONE,ft+AAA,rt+ONE,promo);
                if (appData.debugMode) fprintf(debugFP, "(%d-type) castling %d %d\n", castlingType, ff, ft);