Program: 81395
Project: 81395
Buggy source:
public void onPlayerInteract(PlayerInteractEvent event){
  if (event.getAction() == Action.RIGHT_CLICK_BLOCK && event.getClickedBlock().getType() == Material.CHEST && (Jail.prisoners.containsKey(event.getPlayer().getName().toLowerCase()) || !Util.permission(event.getPlayer(),"String_Node_Str",PermissionDefault.OP))) {
    for (    JailZone jail : Jail.zones.values())     for (    JailCell cell : jail.getCellList()) {
      if ((!jail.getSettings().getBoolean(Setting.CanPrisonerOpenHisChest) || !cell.getPlayerName().toLowerCase().equals(event.getPlayer().getName().toLowerCase())) && ((cell.getChest() != null && event.getClickedBlock() == cell.getChest().getBlock()) || (cell.getSecondChest() != null && event.getClickedBlock() == cell.getSecondChest().getBlock()))) {
        event.setCancelled(true);
        return;
      }
    }
  }
  JailPrisoner prisoner=Jail.prisoners.get(event.getPlayer().getName().toLowerCase());
  if (prisoner != null) {
    JailZone jail=prisoner.getJail();
    if (event.getClickedBlock() != null) {
      int id=event.getClickedBlock().getTypeId();
      if (jail.getSettings().getList(Setting.PreventInteractionBlocks).contains(String.valueOf(id))) {
        if (event.getAction() != Action.PHYSICAL && jail.getSettings().getInt(Setting.InteractionPenalty) > 0 && prisoner.getRemainingTime() > 0) {
          Util.Message(jail.getSettings().getString(Setting.MessagePreventedInteractionPenalty),event.getPlayer());
          prisoner.setRemainingTime(prisoner.getRemainingTime() + jail.getSettings().getInt(Setting.InteractionPenalty) * 6);
          InputOutput.UpdatePrisoner(prisoner);
        }
 else         if (event.getAction() != Action.PHYSICAL) {
          Util.Message(jail.getSettings().getString(Setting.MessagePreventedInteractionNoPenalty),event.getPlayer());
        }
        event.setCancelled(true);
        return;
      }
    }
    if (event.getPlayer().getItemInHand() != null) {
      int id=event.getPlayer().getItemInHand().getTypeId();
      if (jail.getSettings().getList(Setting.PreventInteractionItems).contains(String.valueOf(id))) {
        if (event.getAction() != Action.PHYSICAL && jail.getSettings().getInt(Setting.InteractionPenalty) > 0 && prisoner.getRemainingTime() > 0) {
          Util.Message(jail.getSettings().getString(Setting.MessagePreventedInteractionPenalty),event.getPlayer());
          prisoner.setRemainingTime(prisoner.getRemainingTime() + jail.getSettings().getInt(Setting.InteractionPenalty) * 6);
          InputOutput.UpdatePrisoner(prisoner);
        }
 else         if (event.getAction() != Action.PHYSICAL) {
          Util.Message(jail.getSettings().getString(Setting.MessagePreventedInteractionNoPenalty),event.getPlayer());
        }
        event.setCancelled(true);
        return;
      }
    }
  }
}

Fixed version (ground truth):
public void onPlayerInteract(PlayerInteractEvent event){
  if (event.getAction() == Action.RIGHT_CLICK_BLOCK && event.getClickedBlock().getType() == Material.CHEST && (Jail.prisoners.containsKey(event.getPlayer().getName().toLowerCase()) || !Util.permission(event.getPlayer(),"String_Node_Str",PermissionDefault.OP))) {
    for (    JailZone jail : Jail.zones.values())     for (    JailCell cell : jail.getCellList()) {
      if ((!jail.getSettings().getBoolean(Setting.CanPrisonerOpenHisChest) || !cell.getPlayerName().toLowerCase().equals(event.getPlayer().getName().toLowerCase())) && ((cell.getChest() != null && event.getClickedBlock() == cell.getChest().getBlock()) || (cell.getSecondChest() != null && event.getClickedBlock() == cell.getSecondChest().getBlock()))) {
        event.setCancelled(true);
        return;
      }
    }
  }
  JailPrisoner prisoner=Jail.prisoners.get(event.getPlayer().getName().toLowerCase());
  if (prisoner != null && prisoner.getJail() != null) {
    JailZone jail=prisoner.getJail();
    if (event.getClickedBlock() != null) {
      int id=event.getClickedBlock().getTypeId();
      if (jail.getSettings().getList(Setting.PreventInteractionBlocks).contains(String.valueOf(id))) {
        if (event.getAction() != Action.PHYSICAL && jail.getSettings().getInt(Setting.InteractionPenalty) > 0 && prisoner.getRemainingTime() > 0) {
          Util.Message(jail.getSettings().getString(Setting.MessagePreventedInteractionPenalty),event.getPlayer());
          prisoner.setRemainingTime(prisoner.getRemainingTime() + jail.getSettings().getInt(Setting.InteractionPenalty) * 6);
          InputOutput.UpdatePrisoner(prisoner);
        }
 else         if (event.getAction() != Action.PHYSICAL) {
          Util.Message(jail.getSettings().getString(Setting.MessagePreventedInteractionNoPenalty),event.getPlayer());
        }
        event.setCancelled(true);
        return;
      }
    }
    if (event.getPlayer().getItemInHand() != null) {
      int id=event.getPlayer().getItemInHand().getTypeId();
      if (jail.getSettings().getList(Setting.PreventInteractionItems).contains(String.valueOf(id))) {
        if (event.getAction() != Action.PHYSICAL && jail.getSettings().getInt(Setting.InteractionPenalty) > 0 && prisoner.getRemainingTime() > 0) {
          Util.Message(jail.getSettings().getString(Setting.MessagePreventedInteractionPenalty),event.getPlayer());
          prisoner.setRemainingTime(prisoner.getRemainingTime() + jail.getSettings().getInt(Setting.InteractionPenalty) * 6);
          InputOutput.UpdatePrisoner(prisoner);
        }
 else         if (event.getAction() != Action.PHYSICAL) {
          Util.Message(jail.getSettings().getString(Setting.MessagePreventedInteractionNoPenalty),event.getPlayer());
        }
        event.setCancelled(true);
        return;
      }
    }
  }
}