Fix crash in bench when SyzygyPath is set.

Author: syzygy

src/benchmark.c

@@ -169,11 +169,13 @@ void benchmark(Pos *current, char *str)
   uint64_t nodes = 0;
   Pos pos;
   pos.stack = malloc(101 * sizeof(Stack)); // max perft 100
+  pos.stack++;
   pos.moveList = malloc(10000 * sizeof(ExtMove));
   TimePoint elapsed = now();
 
   for (size_t i = 0; i < num_fens; i++) {
     pos_set(&pos, fens[i], option_value(OPT_CHESS960));
+    (pos.st-1)->endMoves = pos.moveList;
 
     fprintf(stderr, "\nPosition: %" FMT_Z "u/%" FMT_Z "u\n", i + 1, num_fens);
 
@@ -202,7 +204,7 @@ void benchmark(Pos *current, char *str)
       free(fens[i]);
     free(fens);
   }
-  free(pos.stack);
+  free(pos.stack - 1);
   free(pos.moveList);
 }
 

src/position.c

@@ -1063,8 +1063,18 @@ void do_move(Pos *pos, Move m, int givesCheck)
   st->key = key;
 
   // Calculate checkers bitboard (if move gives check)
+#if 1
   st->checkersBB =  givesCheck
                   ? attackers_to(square_of(them, KING)) & pieces_c(us) : 0;
+#else
+  st->checkersBB = 0;
+  if (givesCheck) {
+    if (type_of_m(m) != NORMAL || ((st-1)->blockersForKing[them] & sq_bb(from)))
+      st->checkersBB = attackers_to(square_of(them, KING)) & pieces_c(us);
+    else
+      st->checkersBB = (st-1)->checkSquares[piece & 7] & sq_bb(to);
+  }
+#endif
 
   pos->sideToMove ^= 1;