Program: 187675
Project: 187675
Buggy source:
public void Timer(){
  if (Status != WolfState.Despawned) {
    if (Timer != -1) {
      StopTimer();
    }
    Timer=MyWolfPlugin.Plugin.getServer().getScheduler().scheduleSyncRepeatingTask(MyWolfPlugin.Plugin,new Runnable(){
      int Time2HPregen=Healthregen;
      public void run(){
        if (Status == WolfState.Despawned || getOwner() == null) {
          StopTimer();
        }
 else {
          if (Status == WolfState.Here) {
            Time2HPregen--;
            SitTimer--;
            if (MyWolfConfig.SitdownTime > 0 && SitTimer <= 0) {
              Wolf.setSitting(true);
            }
            if (Time2HPregen <= 0) {
              Time2HPregen=Healthregen;
              if (MyWolfUtil.hasSkill(Abilities,"String_Node_Str") && getHealth() < HealthMax) {
                setHealth(getHealth() + 1);
              }
            }
            if (isPickup) {
              for (              Entity e : Wolf.getNearbyEntities(MyWolfConfig.PickupRange,MyWolfConfig.PickupRange,MyWolfConfig.PickupRange)) {
                if (e instanceof Item) {
                  Item item=(Item)e;
                  PlayerPickupItemEvent ppievent=new PlayerPickupItemEvent(getOwner(),item,item.getItemStack().getAmount());
                  MyWolfUtil.getServer().getPluginManager().callEvent(ppievent);
                  if (ppievent.isCancelled()) {
                    continue;
                  }
                  int ItemID=item.getItemStack().getTypeId();
                  int ItemDuarbility=item.getItemStack().getDurability();
                  int ItemAmount=item.getItemStack().getAmount();
                  int ItemMaxStack=item.getItemStack().getMaxStackSize();
                  for (int i=0; i < inv.getSize(); i++) {
                    if (inv.getItem(i) != null && inv.getItem(i).id == ItemID && inv.getItem(i).damage == ItemDuarbility && inv.getItem(i).count < ItemMaxStack) {
                      if (ItemAmount >= ItemMaxStack - inv.getItem(i).count) {
                        ItemAmount=ItemAmount - (ItemMaxStack - inv.getItem(i).count);
                        inv.getItem(i).count=ItemMaxStack;
                      }
 else {
                        inv.getItem(i).count+=ItemAmount;
                        ItemAmount=0;
                        break;
                      }
                    }
                  }
                  for (int i=0; i < inv.getSize(); i++) {
                    if (ItemAmount <= 0) {
                      break;
                    }
                    if (inv.getItem(i) == null) {
                      if (ItemAmount <= ItemMaxStack) {
                        inv.setItem(i,new ItemStack(ItemID,ItemAmount,ItemDuarbility));
                        ItemAmount=0;
                      }
 else {
                        inv.setItem(i,new ItemStack(ItemID,ItemMaxStack,ItemDuarbility));
                        ItemAmount-=ItemMaxStack;
                      }
                    }
                  }
                  if (ItemAmount == 0) {
                    e.remove();
                  }
 else {
                    item.getItemStack().setAmount(ItemAmount);
                  }
                }
              }
            }
            if (Behavior == BehaviorState.Aggressive) {
              if (Wolf.getTarget() == null || Wolf.getTarget().isDead()) {
                for (                Entity e : Wolf.getNearbyEntities(10,10,10)) {
                  if (MyWolfUtil.getCreatureType(e) != null) {
                    Wolf.setTarget((LivingEntity)e);
                  }
                }
              }
            }
          }
          if (Status == WolfState.Dead) {
            RespawnTime--;
            if (RespawnTime <= 0) {
              RespawnWolf();
            }
          }
        }
      }
    }
,0L,20L);
  }
}

Fixed version (ground truth):
public void Timer(){
  if (Status != WolfState.Despawned) {
    if (Timer != -1) {
      StopTimer();
    }
    Timer=MyWolfPlugin.Plugin.getServer().getScheduler().scheduleSyncRepeatingTask(MyWolfPlugin.Plugin,new Runnable(){
      int Time2HPregen=Healthregen;
      public void run(){
        if (Status == WolfState.Despawned || getOwner() == null) {
          StopTimer();
        }
 else {
          if (Status == WolfState.Here) {
            Time2HPregen--;
            SitTimer--;
            if (MyWolfConfig.SitdownTime > 0 && SitTimer <= 0) {
              Wolf.setSitting(true);
            }
            if (Time2HPregen <= 0) {
              Time2HPregen=Healthregen;
              if (MyWolfUtil.hasSkill(Abilities,"String_Node_Str") && getHealth() < HealthMax) {
                setHealth(getHealth() + 1);
              }
            }
            if (isPickup) {
              for (              Entity e : Wolf.getNearbyEntities(MyWolfConfig.PickupRange,MyWolfConfig.PickupRange,MyWolfConfig.PickupRange)) {
                if (e instanceof Item) {
                  Item item=(Item)e;
                  PlayerPickupItemEvent ppievent=new PlayerPickupItemEvent(getOwner(),item,item.getItemStack().getAmount());
                  MyWolfUtil.getServer().getPluginManager().callEvent(ppievent);
                  if (ppievent.isCancelled()) {
                    continue;
                  }
                  int ItemID=item.getItemStack().getTypeId();
                  int ItemDuarbility=item.getItemStack().getDurability();
                  int ItemAmount=item.getItemStack().getAmount();
                  int ItemMaxStack=item.getItemStack().getMaxStackSize();
                  for (int i=0; i < inv.getSize(); i++) {
                    if (inv.getItem(i) != null && inv.getItem(i).id == ItemID && inv.getItem(i).getData() == ItemDuarbility && inv.getItem(i).count < ItemMaxStack) {
                      if (ItemAmount >= ItemMaxStack - inv.getItem(i).count) {
                        ItemAmount=ItemAmount - (ItemMaxStack - inv.getItem(i).count);
                        inv.getItem(i).count=ItemMaxStack;
                      }
 else {
                        inv.getItem(i).count+=ItemAmount;
                        ItemAmount=0;
                        break;
                      }
                    }
                  }
                  for (int i=0; i < inv.getSize(); i++) {
                    if (ItemAmount <= 0) {
                      break;
                    }
                    if (inv.getItem(i) == null) {
                      if (ItemAmount <= ItemMaxStack) {
                        inv.setItem(i,new ItemStack(ItemID,ItemAmount,ItemDuarbility));
                        ItemAmount=0;
                      }
 else {
                        inv.setItem(i,new ItemStack(ItemID,ItemMaxStack,ItemDuarbility));
                        ItemAmount-=ItemMaxStack;
                      }
                    }
                  }
                  if (ItemAmount == 0) {
                    e.remove();
                  }
 else {
                    item.getItemStack().setAmount(ItemAmount);
                  }
                }
              }
            }
            if (Behavior == BehaviorState.Aggressive) {
              if (Wolf.getTarget() == null || Wolf.getTarget().isDead()) {
                for (                Entity e : Wolf.getNearbyEntities(10,10,10)) {
                  if (MyWolfUtil.getCreatureType(e) != null) {
                    Wolf.setTarget((LivingEntity)e);
                  }
                }
              }
            }
          }
          if (Status == WolfState.Dead) {
            RespawnTime--;
            if (RespawnTime <= 0) {
              RespawnWolf();
            }
          }
        }
      }
    }
,0L,20L);
  }
}