Program: 81420
Project: 81420
Buggy source:
public static void Transfer(JailPrisoner prisoner,Player player){
  if (prisoner.getTransferDestination() == "String_Node_Str")   prisoner.setTransferDestination(JailZoneManager.findNearestJail(player.getLocation(),prisoner.getJail().getName()).getName());
  if (prisoner.getCell() != null) {
    Inventory inventory=player.getInventory();
    JailCell cell=prisoner.getCell();
    cell.setPlayerName("String_Node_Str");
    if (cell.getSign() != null) {
      Sign sign=cell.getSign();
      sign.setLine(0,"String_Node_Str");
      sign.setLine(1,"String_Node_Str");
      sign.setLine(2,"String_Node_Str");
      sign.setLine(3,"String_Node_Str");
      sign.update();
    }
    if (cell.getChest() != null) {
      for (      ItemStack i : cell.getChest().getInventory().getContents())       inventory.addItem(i);
      cell.getChest().getInventory().clear();
    }
    if (cell.getSecondChest() != null) {
      for (      ItemStack i : cell.getSecondChest().getInventory().getContents())       inventory.addItem(i);
      cell.getSecondChest().getInventory().clear();
    }
    prisoner.setCell(null);
  }
  prisoner.SetBeingReleased(true);
  JailZone jail=Jail.zones.get(prisoner.getTransferDestination());
  prisoner.setJail(jail);
  prisoner.setTransferDestination("String_Node_Str");
  prisoner.setOfflinePending(false);
  Util.Message(Settings.MessageTransfer,player);
  Jail.prisoners.put(prisoner.getName(),prisoner);
  JailCell cell=jail.getEmptyCell();
  if (cell != null) {
    cell.setPlayerName(player.getName());
    prisoner.setCell(cell);
    prisoner.updateSign();
    if (Settings.StoreInventory && cell.getChest() != null) {
      Chest chest=cell.getChest();
      chest.getInventory().clear();
      for (int i=0; i < player.getInventory().getSize(); i++) {
        if (chest.getInventory().getSize() <= Util.getNumberOfOccupiedItemSlots(chest.getInventory().getContents()))         break;
        if (player.getInventory().getItem(i) == null || player.getInventory().getItem(i).getType() == Material.AIR)         continue;
        chest.getInventory().addItem(player.getInventory().getItem(i));
        player.getInventory().clear(i);
      }
      if (cell.getSecondChest() != null) {
        chest=cell.getSecondChest();
        chest.getInventory().clear();
        for (int i=0; i < player.getInventory().getSize(); i++) {
          if (chest.getInventory().getSize() <= Util.getNumberOfOccupiedItemSlots(chest.getInventory().getContents()))           break;
          if (player.getInventory().getItem(i) == null || player.getInventory().getItem(i).getType() == Material.AIR)           continue;
          chest.getInventory().addItem(player.getInventory().getItem(i));
          player.getInventory().clear(i);
        }
      }
    }
    InputOutput.UpdateCell(cell);
  }
  if (Settings.StoreInventory) {
    prisoner.storeInventory(player.getInventory());
    player.getInventory().clear();
  }
  player.teleport(prisoner.getTeleportLocation());
  prisoner.SetBeingReleased(false);
  InputOutput.UpdatePrisoner(prisoner);
}

Fixed version (ground truth):
public static void Transfer(JailPrisoner prisoner,Player player){
  if (prisoner.getTransferDestination() == "String_Node_Str")   prisoner.setTransferDestination(JailZoneManager.findNearestJail(player.getLocation(),prisoner.getJail().getName()).getName());
  if (prisoner.getCell() != null) {
    Inventory inventory=player.getInventory();
    JailCell cell=prisoner.getCell();
    cell.setPlayerName("String_Node_Str");
    if (cell.getSign() != null) {
      Sign sign=cell.getSign();
      sign.setLine(0,"String_Node_Str");
      sign.setLine(1,"String_Node_Str");
      sign.setLine(2,"String_Node_Str");
      sign.setLine(3,"String_Node_Str");
      sign.update();
    }
    if (cell.getChest() != null) {
      for (      ItemStack i : cell.getChest().getInventory().getContents()) {
        if (i == null || i.getType() == Material.AIR)         continue;
        inventory.addItem(i);
      }
      cell.getChest().getInventory().clear();
    }
    if (cell.getSecondChest() != null) {
      for (      ItemStack i : cell.getSecondChest().getInventory().getContents()) {
        if (i == null || i.getType() == Material.AIR)         continue;
        inventory.addItem(i);
      }
      cell.getSecondChest().getInventory().clear();
    }
    prisoner.setCell(null);
  }
  prisoner.SetBeingReleased(true);
  JailZone jail=Jail.zones.get(prisoner.getTransferDestination());
  prisoner.setJail(jail);
  prisoner.setTransferDestination("String_Node_Str");
  prisoner.setOfflinePending(false);
  Util.Message(Settings.MessageTransfer,player);
  Jail.prisoners.put(prisoner.getName(),prisoner);
  JailCell cell=jail.getEmptyCell();
  if (cell != null) {
    cell.setPlayerName(player.getName());
    prisoner.setCell(cell);
    prisoner.updateSign();
    if (Settings.StoreInventory && cell.getChest() != null) {
      Chest chest=cell.getChest();
      chest.getInventory().clear();
      for (int i=0; i < player.getInventory().getSize(); i++) {
        if (chest.getInventory().getSize() <= Util.getNumberOfOccupiedItemSlots(chest.getInventory().getContents()))         break;
        if (player.getInventory().getItem(i) == null || player.getInventory().getItem(i).getType() == Material.AIR)         continue;
        chest.getInventory().addItem(player.getInventory().getItem(i));
        player.getInventory().clear(i);
      }
      if (cell.getSecondChest() != null) {
        chest=cell.getSecondChest();
        chest.getInventory().clear();
        for (int i=0; i < player.getInventory().getSize(); i++) {
          if (chest.getInventory().getSize() <= Util.getNumberOfOccupiedItemSlots(chest.getInventory().getContents()))           break;
          if (player.getInventory().getItem(i) == null || player.getInventory().getItem(i).getType() == Material.AIR)           continue;
          chest.getInventory().addItem(player.getInventory().getItem(i));
          player.getInventory().clear(i);
        }
      }
    }
    InputOutput.UpdateCell(cell);
  }
  if (Settings.StoreInventory) {
    prisoner.storeInventory(player.getInventory());
    player.getInventory().clear();
  }
  player.teleport(prisoner.getTeleportLocation());
  prisoner.SetBeingReleased(false);
  InputOutput.UpdatePrisoner(prisoner);
}