Fix bare-king adjudication in Atomic

In Atomic a bare King cannot win, but it can already have won, when
the last piece of that side captured or destroyed the opponent King
when exploding. The win-to-draw correction now recognizes this
situation, so that the win is uphold there.

diff --git a/backend.c b/backend.c
index 6ec7be2..0d7a577 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -11420,16 +11420,17 @@ GameEnds (ChessMove result, char *resultDetails, int whosays)
               && gameInfo.variant != VariantLosers && gameInfo.variant != VariantGiveaway
               && gameInfo.variant != VariantSuicide // [HGM] losers: except in losers, of course...
               && result != GameIsDrawn)
-           {   int i, j, k=0, color = (result==WhiteWins ? (int)WhitePawn : (int)BlackPawn);
+           {   int i, j, k=0, oppoKings = 0, color = (result==WhiteWins ? (int)WhitePawn : (int)BlackPawn);
                for(j=BOARD_LEFT; j<BOARD_RGHT; j++) for(i=0; i<BOARD_HEIGHT; i++) {
                        int p = (signed char)boards[forwardMostMove][i][j] - color;
                        if(p >= 0 && p <= (int)WhiteKing) k++;
+                       oppoKings += (p + color == WhiteKing + BlackPawn - color);
                }
                if (appData.debugMode) {
                     fprintf(debugFP, "GE(%d, %s, %d) bare king k=%d color=%d\n",
                        result, resultDetails ? resultDetails : "(null)", whosays, k, color);
                }
-               if(k <= 1) {
+               if(k <= 1 && oppoKings > 0) { // the latter needed in Atomic, where bare K wins if opponent King already destroyed
                        result = GameIsDrawn;
                        snprintf(buf, MSG_SIZ, "%s but bare king", resultDetails);
                        resultDetails = buf;