Program: 68939
Project: 68939
Buggy source:
public WinrateHistogramTableModel(){
  histogramEntryList=new ArrayList<>();
  histogramEntryFilteredList=new ArrayList<>();
  provideFilteredData=true;
  Lizzie.board.registerBoardStateChangeObserver(new BoardStateChangeObserver(){
    @Override public void mainStreamAppended(    BoardHistoryNode newNodeBegin,    BoardHistoryNode head){
      newNodeBegin.forEach(WinrateHistogramTableModel.this::addHistogramData);
      rebuildFilteredHistogramData();
      fireTableDataChanged();
      if (refreshObserver != null) {
        Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
      }
    }
    @Override public void mainStreamCut(    BoardHistoryNode nodeBeforeCutPoint,    BoardHistoryNode head){
      histogramEntryList.removeIf(entry -> entry.getMoveNumber() > nodeBeforeCutPoint.getData().getMoveNumber());
      histogramEntryFilteredList.removeIf(entry -> entry.getMoveNumber() > nodeBeforeCutPoint.getData().getMoveNumber());
      rebuildFilteredHistogramData();
      fireTableDataChanged();
      if (refreshObserver != null) {
        Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
      }
    }
    @Override public void headMoved(    BoardHistoryNode oldHead,    BoardHistoryNode newHead){
      int lastMoveNumberInTable=histogramEntryList.get(histogramEntryList.size() - 1).getMoveNumber();
      if (newHead.getData().getMoveNumber() > lastMoveNumberInTable) {
        BoardHistoryNode node=oldHead.getNext();
        do {
          addHistogramData(node.getData());
        }
 while (node != newHead);
      }
 else {
        histogramEntryList.removeIf(entry -> entry.getMoveNumber() > newHead.getData().getMoveNumber());
      }
      rebuildFilteredHistogramData();
      if (refreshObserver != null) {
        Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
      }
    }
    @Override public void boardCleared(){
      histogramEntryList.clear();
      histogramEntryFilteredList.clear();
      fireTableDataChanged();
      if (refreshObserver != null) {
        Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
      }
    }
  }
);
  Lizzie.leelaz.registerBestMoveObserver(new BestMoveObserver(){
    @Override public void bestMovesUpdated(    int boardStateCount,    List<MoveData> newBestMoves){
      if (boardStateCount < histogramEntryList.size() && CollectionUtils.isNotEmpty(newBestMoves)) {
        MoveData moveData=newBestMoves.get(0);
        WinrateHistogramEntry histogramEntry=histogramEntryList.get(boardStateCount);
        if (Objects.equals(histogramEntry.getColor(),WinrateHistogramEntry.COLOR_BLACK)) {
          histogramEntry.setWhiteWinrate(moveData.getWinrate());
        }
 else {
          histogramEntry.setBlackWinrate(moveData.getWinrate());
        }
        if (boardStateCount > 0) {
          histogramEntry.setBlackWindiff(histogramEntry.getBlackWinrate() - histogramEntryList.get(boardStateCount - 1).getBlackWinrate());
        }
        rebuildFilteredHistogramData();
        fireTableDataChanged();
        if (refreshObserver != null) {
          Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
        }
      }
    }
    @Override public void engineRestarted(){
    }
  }
);
}

Fixed version (ground truth):
public WinrateHistogramTableModel(){
  histogramEntryList=new ArrayList<>();
  histogramEntryFilteredList=new ArrayList<>();
  provideFilteredData=true;
  Lizzie.board.registerBoardStateChangeObserver(new BoardStateChangeObserver(){
    @Override public void mainStreamAppended(    BoardHistoryNode newNodeBegin,    BoardHistoryNode head){
      newNodeBegin.forEach(WinrateHistogramTableModel.this::addHistogramData);
      rebuildFilteredHistogramData();
      fireTableDataChanged();
      if (refreshObserver != null) {
        Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
      }
    }
    @Override public void mainStreamCut(    BoardHistoryNode nodeBeforeCutPoint,    BoardHistoryNode head){
      histogramEntryList.removeIf(entry -> entry.getMoveNumber() > nodeBeforeCutPoint.getData().getMoveNumber());
      histogramEntryFilteredList.removeIf(entry -> entry.getMoveNumber() > nodeBeforeCutPoint.getData().getMoveNumber());
      rebuildFilteredHistogramData();
      fireTableDataChanged();
      if (refreshObserver != null) {
        Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
      }
    }
    @Override public void headMoved(    BoardHistoryNode oldHead,    BoardHistoryNode newHead){
      int lastMoveNumberInTable=histogramEntryList.get(histogramEntryList.size() - 1).getMoveNumber();
      if (newHead.getData().getMoveNumber() > lastMoveNumberInTable) {
        BoardHistoryNode node;
        do {
          node=oldHead.getNext();
          addHistogramData(node.getData());
        }
 while (node != newHead);
      }
 else {
        histogramEntryList.removeIf(entry -> entry.getMoveNumber() > newHead.getData().getMoveNumber());
      }
      rebuildFilteredHistogramData();
      if (refreshObserver != null) {
        Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
      }
    }
    @Override public void boardCleared(){
      histogramEntryList.clear();
      histogramEntryFilteredList.clear();
      fireTableDataChanged();
      if (refreshObserver != null) {
        Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
      }
    }
  }
);
  Lizzie.leelaz.registerBestMoveObserver(new BestMoveObserver(){
    @Override public void bestMovesUpdated(    int boardStateCount,    List<MoveData> newBestMoves){
      if (boardStateCount < histogramEntryList.size() && CollectionUtils.isNotEmpty(newBestMoves)) {
        MoveData moveData=newBestMoves.get(0);
        WinrateHistogramEntry histogramEntry=histogramEntryList.get(boardStateCount);
        if (Objects.equals(histogramEntry.getColor(),WinrateHistogramEntry.COLOR_BLACK)) {
          histogramEntry.setWhiteWinrate(moveData.getWinrate());
        }
 else {
          histogramEntry.setBlackWinrate(moveData.getWinrate());
        }
        if (boardStateCount > 0) {
          histogramEntry.setBlackWindiff(histogramEntry.getBlackWinrate() - histogramEntryList.get(boardStateCount - 1).getBlackWinrate());
        }
        rebuildFilteredHistogramData();
        fireTableDataChanged();
        if (refreshObserver != null) {
          Lizzie.miscExecutor.execute(() -> refreshObserver.accept(WinrateHistogramTableModel.this));
        }
      }
    }
    @Override public void engineRestarted(){
    }
  }
);
}