Program: 187519
Project: 187519
Buggy source:
@Override public boolean shouldStart(){
  if (!petEntity.canMove()) {
    return false;
  }
  if (myPet.getDamage() <= 0 && myPet.getRangedDamage() <= 0) {
    return false;
  }
  this.lastDamager=owner.getLastDamager();
  if (this.lastDamager == null || !lastDamager.isAlive()) {
    return false;
  }
  if (lastDamager == petEntity) {
    return false;
  }
  if (lastDamager instanceof EntityPlayer) {
    if (owner == lastDamager) {
      return false;
    }
    Player targetPlayer=(Player)lastDamager.getBukkitEntity();
    if (!PvPChecker.canHurt(myPet.getOwner().getPlayer(),targetPlayer)) {
      return false;
    }
  }
 else   if (lastDamager instanceof EntityMyPet) {
    MyPet targetMyPet=((EntityMyPet)lastDamager).getMyPet();
    if (!PvPChecker.canHurt(myPet.getOwner().getPlayer(),targetMyPet.getOwner().getPlayer())) {
      return false;
    }
  }
 else   if (lastDamager instanceof EntityTameableAnimal) {
    EntityTameableAnimal tameable=(EntityTameableAnimal)lastDamager;
    if (tameable.isTamed() && tameable.getOwner() != null) {
      Player tameableOwner=(Player)tameable.getOwner().getBukkitEntity();
      if (myPet.getOwner().equals(tameableOwner)) {
        return false;
      }
    }
  }
  if (behaviorSkill != null && behaviorSkill.isActive()) {
    if (behaviorSkill.getBehavior() == Behavior.BehaviorState.Friendly) {
      return false;
    }
    if (behaviorSkill.getBehavior() == BehaviorState.Raid) {
      if (lastDamager instanceof EntityTameableAnimal && ((EntityTameableAnimal)lastDamager).isTamed()) {
        return false;
      }
      if (lastDamager instanceof EntityMyPet) {
        return false;
      }
      if (lastDamager instanceof EntityPlayer) {
        return false;
      }
    }
  }
  return true;
}

Fixed version (ground truth):
@Override public boolean shouldStart(){
  if (!petEntity.canMove()) {
    return false;
  }
  if (myPet.getDamage() <= 0 && myPet.getRangedDamage() <= 0) {
    return false;
  }
  this.lastDamager=owner.getLastDamager();
  if (this.lastDamager == null || !lastDamager.isAlive()) {
    return false;
  }
  if (lastDamager == petEntity) {
    return false;
  }
  if (lastDamager instanceof EntityPlayer) {
    if (owner == lastDamager) {
      return false;
    }
    Player targetPlayer=(Player)lastDamager.getBukkitEntity();
    if (!PvPChecker.canHurt(myPet.getOwner().getPlayer(),targetPlayer)) {
      return false;
    }
  }
 else   if (lastDamager instanceof EntityMyPet) {
    MyPet targetMyPet=((EntityMyPet)lastDamager).getMyPet();
    if (!PvPChecker.canHurt(myPet.getOwner().getPlayer(),targetMyPet.getOwner().getPlayer())) {
      return false;
    }
  }
 else   if (lastDamager instanceof EntityTameableAnimal) {
    EntityTameableAnimal tameable=(EntityTameableAnimal)lastDamager;
    if (tameable.isTamed() && tameable.getOwner() != null) {
      Player tameableOwner=(Player)tameable.getOwner().getBukkitEntity();
      if (myPet.getOwner().equals(tameableOwner)) {
        return false;
      }
    }
  }
  if (!PvPChecker.canHurtCitizens(lastDamager.getBukkitEntity())) {
    return false;
  }
  if (behaviorSkill != null && behaviorSkill.isActive()) {
    if (behaviorSkill.getBehavior() == Behavior.BehaviorState.Friendly) {
      return false;
    }
    if (behaviorSkill.getBehavior() == BehaviorState.Raid) {
      if (lastDamager instanceof EntityTameableAnimal && ((EntityTameableAnimal)lastDamager).isTamed()) {
        return false;
      }
      if (lastDamager instanceof EntityMyPet) {
        return false;
      }
      if (lastDamager instanceof EntityPlayer) {
        return false;
      }
    }
  }
  return true;
}