Fix crash when generating legal moves

ChessAndroid/app/src/main/cpp/chess/BoardManager.cpp

@@ -21,7 +21,7 @@ void BoardManager::initBoardManager(const PieceChangeListener &listener, const b
 
 	s_MovesHistory.clear();
 	s_MovesHistory.reserve(200);
-	s_MovesHistory.emplace_back(0u, 0u, s_Board);
+	s_MovesHistory.emplace_back(64u, 64u, s_Board);
 
 	Stats::resetStats();
 
@@ -37,18 +37,22 @@ void BoardManager::loadGame(const std::vector<std::pair<byte, byte>> &moves, con
 
 	s_Board.initDefaultBoard();
 
-	s_MovesHistory.emplace_back(0u, 0u, s_Board);
+	s_MovesHistory.clear();
+	s_MovesHistory.emplace_back(64u, 64u, s_Board);
 
     try {
         for (const auto &move : moves)
         {
-            s_Board.doMove(move.first, move.second);
-            s_Board.score = Evaluation::evaluate(s_Board);
-            s_MovesHistory.emplace_back(move.first, move.second, s_Board);
+			s_Board.doMove(move.first, move.second);
+			s_Board.score = Evaluation::evaluate(s_Board);
+			s_MovesHistory.emplace_back(move.first, move.second, s_Board);
         }
     } catch (...) {
-        // Couldn't load all moves correctly
-    }
+        // Couldn't load all moves correctly, fallback to the original board
+        s_Board.initDefaultBoard();
+        s_MovesHistory.clear();
+		s_MovesHistory.emplace_back(64u, 64u, s_Board);
+	}
 
 	s_Listener(s_Board.state, true, {});
 }
@@ -107,13 +111,12 @@ void BoardManager::moveComputerPlayer(const Settings &settings)
 	Stats::resetStats();
 	Stats::startTimer();
 
-	assert(s_Board.colorToMove != toColor(s_IsPlayerWhite));
 	const RootMove bestMove = NegaMax::findBestMove(s_Board, settings);
 
 	Stats::stopTimer();
-	s_IsWorking = false;
 	movePiece(bestMove.startSq, bestMove.destSq, false);
 
+	s_IsWorking = false;
 	s_WorkerThread.detach();
 }
 

ChessAndroid/app/src/main/cpp/chess/algorithm/NegaMax.cpp

@@ -15,6 +15,7 @@ short NegaMax::s_BestMoveFound{};
 RootMove NegaMax::findBestMove(const Board &board, const Settings &settings)
 {
 	const auto validMoves = board.listValidMoves<RootMove>();
+	assert(!validMoves.empty());
 
 	for (const RootMove &move : validMoves)
 		if (move.board.state == State::WINNER_WHITE || move.board.state == State::WINNER_BLACK)
@@ -25,7 +26,7 @@ RootMove NegaMax::findBestMove(const Board &board, const Settings &settings)
 	const auto threadCount = settings.getThreadCount();
 	s_QuiescenceSearchEnabled = settings.performQuiescenceSearch();
 
-	// If the Transposition Table wasn't resized, clean it
+	// If the Transposition Table wasn't resized, increment its age
 	if (!s_SearchCache.setSize(settings.getCacheTableSizeMb()))
 		s_SearchCache.incrementAge();
 	NegaMaxThreadPool::updateThreadCount(threadCount);
@@ -90,7 +91,7 @@ RootMove NegaMax::negaMaxRoot(const std::vector<RootMove> &validMoves, const uns
 	for (auto &future : futures)
 		future.get(); // Wait for the Search to finish
 
-	s_BestMoveFound = alpha;
+	s_BestMoveFound = validMoves.front().board.colorToMove ? alpha : -alpha;
 
 	return bestMove;
 }

ChessAndroid/app/src/main/cpp/chess/data/Board.cpp

@@ -230,7 +230,7 @@ std::vector<Board> Board::listQuiescenceMoves() const
 
 		assert(possibleMoves == (possibleMoves & allPieces[oppositeColor(colorToMove)]));
 		// Make sure we are not capturing the king
-		possibleMoves &= getType(colorToMove, KING);
+		possibleMoves &= ~getType(colorToMove, KING);
 
 		while (possibleMoves)
 		{

ChessAndroid/app/src/main/cpp/chess/data/Board.h

@@ -116,7 +116,7 @@ std::vector<T> Board::listValidMoves() const noexcept
 		U64 possibleMoves = selectedPiece.getPossibleMoves(startSq, *this);
 
 		// Make sure we are not capturing the king
-		possibleMoves &= getType(colorToMove, KING);
+		possibleMoves &= ~getType(colorToMove, KING);
 
 		while (possibleMoves)
 		{