Program: 81389
Project: 81389
Buggy source:
public void actionPerformed(ActionEvent event){
  if (Jail.timeUpdateRunning)   return;
  Jail.timeUpdateRunning=true;
  if (UpdateTime == 0) {
    getServer().getScheduler().scheduleSyncDelayedTask(Jail.instance,new Runnable(){
      public void run(){
        for (        JailPrisoner prisoner : prisoners.values().toArray(new JailPrisoner[0])) {
          Util.debug(prisoner,"String_Node_Str");
          Player player=getServer().getPlayerExact(prisoner.getName());
          if (prisoner.getRemainingTime() > 0 && (player != null || (prisoner.getJail() != null && prisoner.getJail().getSettings().getBoolean(Setting.CountdownTimeWhenOffline)))) {
            Util.debug(prisoner,"String_Node_Str");
            prisoner.setRemainingTime(prisoner.getRemainingTime() - 1);
            InputOutput.UpdatePrisoner(prisoner);
            if (prisoner.getRemainingTime() == 0) {
              Util.debug(prisoner,"String_Node_Str");
              prisoner.release();
            }
          }
          if (player != null && prisoner.getJail() != null) {
            if (prisoner.getJail().getSettings().getDouble(Setting.MaximumAFKTime) > 0.0) {
              prisoner.setAFKTime(prisoner.getAFKTime() + 1);
              if (prisoner.getAFKTimeMinutes() > prisoner.getJail().getSettings().getDouble(Setting.MaximumAFKTime)) {
                Util.debug(prisoner,"String_Node_Str");
                prisoner.setAFKTime(0);
                player.kickPlayer(prisoner.getJail().getSettings().getString(Setting.MessageAFKKick));
              }
            }
          }
        }
      }
    }
,1L);
    UpdateTime++;
  }
 else {
    UpdateTime++;
    if (UpdateTime > 9) {
      UpdateTime=0;
    }
  }
  for (  JailPrisoner prisoner : prisoners.values()) {
    Player player=getServer().getPlayerExact(prisoner.getName());
    if (player == null || prisoner.getJail() == null || player.getGameMode() == GameMode.CREATIVE)     continue;
    if (!prisoner.getJail().getSettings().getBoolean(Setting.EnableFoodControl))     continue;
    int minfood=prisoner.getJail().getSettings().getInt(Setting.FoodControlMinimumFood);
    int maxfood=prisoner.getJail().getSettings().getInt(Setting.FoodControlMaximumFood);
    if (player.getFoodLevel() < minfood || player.getFoodLevel() > maxfood) {
      player.setFoodLevel((minfood + maxfood) / 2);
    }
  }
  Jail.timeUpdateRunning=false;
}

Fixed version (ground truth):
public void actionPerformed(ActionEvent event){
  if (Jail.timeUpdateRunning)   return;
  Jail.timeUpdateRunning=true;
  if (UpdateTime == 0) {
    getServer().getScheduler().scheduleSyncDelayedTask(Jail.instance,new Runnable(){
      public void run(){
        for (        JailPrisoner prisoner : prisoners.values().toArray(new JailPrisoner[0])) {
          Util.debug(prisoner,"String_Node_Str");
          Util.debug(prisoner,"String_Node_Str" + prisoner.getName() + "String_Node_Str");
          Player player=getServer().getPlayerExact(prisoner.getName());
          Util.debug(prisoner,"String_Node_Str" + prisoner.getRemainingTime());
          Util.debug("String_Node_Str" + String.valueOf(player));
          if (prisoner.getRemainingTime() > 0 && (player != null || (prisoner.getJail() != null && prisoner.getJail().getSettings().getBoolean(Setting.CountdownTimeWhenOffline)))) {
            Util.debug(prisoner,"String_Node_Str");
            prisoner.setRemainingTime(prisoner.getRemainingTime() - 1);
            InputOutput.UpdatePrisoner(prisoner);
            if (prisoner.getRemainingTime() == 0) {
              Util.debug(prisoner,"String_Node_Str");
              prisoner.release();
            }
          }
          if (player != null && prisoner.getJail() != null) {
            if (prisoner.getJail().getSettings().getDouble(Setting.MaximumAFKTime) > 0.0) {
              prisoner.setAFKTime(prisoner.getAFKTime() + 1);
              if (prisoner.getAFKTimeMinutes() > prisoner.getJail().getSettings().getDouble(Setting.MaximumAFKTime)) {
                Util.debug(prisoner,"String_Node_Str");
                prisoner.setAFKTime(0);
                player.kickPlayer(prisoner.getJail().getSettings().getString(Setting.MessageAFKKick));
              }
            }
          }
        }
      }
    }
,1L);
    UpdateTime++;
  }
 else {
    UpdateTime++;
    if (UpdateTime > 9) {
      UpdateTime=0;
    }
  }
  for (  JailPrisoner prisoner : prisoners.values()) {
    Player player=getServer().getPlayerExact(prisoner.getName());
    if (player == null || prisoner.getJail() == null || player.getGameMode() == GameMode.CREATIVE)     continue;
    if (!prisoner.getJail().getSettings().getBoolean(Setting.EnableFoodControl))     continue;
    int minfood=prisoner.getJail().getSettings().getInt(Setting.FoodControlMinimumFood);
    int maxfood=prisoner.getJail().getSettings().getInt(Setting.FoodControlMaximumFood);
    if (player.getFoodLevel() < minfood || player.getFoodLevel() > maxfood) {
      player.setFoodLevel((minfood + maxfood) / 2);
    }
  }
  Jail.timeUpdateRunning=false;
}