Program: 49307
Project: 49307
Buggy source:
public List<PoolUpdate> updatePools(Pool masterPool,List<Pool> existingPools,Set<Product> changedProducts){
  log.debug("String_Node_Str" + masterPool);
  log.debug("String_Node_Str" + existingPools.size());
  PoolHelper helper=new PoolHelper(this.poolManager,null);
  List<PoolUpdate> poolsUpdated=new LinkedList<PoolUpdate>();
  Map<String,String> attributes=helper.getFlattenedAttributes(masterPool.getProduct());
  for (  Pool existingPool : existingPools) {
    log.debug("String_Node_Str" + existingPool.getId());
    if ("String_Node_Str".equalsIgnoreCase(existingPool.getSubscriptionSubKey())) {
      existingPool.setUpstreamPoolId(masterPool.getUpstreamPoolId());
      existingPool.setUpstreamEntitlementId(masterPool.getUpstreamEntitlementId());
      existingPool.setUpstreamConsumerId(masterPool.getUpstreamConsumerId());
      existingPool.setCdn(masterPool.getCdn());
      existingPool.setCertificate(masterPool.getCertificate());
    }
    PoolUpdate update=new PoolUpdate(existingPool);
    update.setDatesChanged(checkForDateChange(masterPool.getStartDate(),masterPool.getEndDate(),existingPool));
    update.setQuantityChanged(checkForQuantityChange(masterPool,existingPool,existingPools,attributes));
    if (!existingPool.isMarkedForDelete()) {
      boolean useDerived=BooleanUtils.toBoolean(existingPool.getAttributeValue("String_Node_Str")) && masterPool.getDerivedProduct() != null;
      update.setProductsChanged(checkForChangedProducts(useDerived ? masterPool.getDerivedProduct() : masterPool.getProduct(),getExpectedProvidedProducts(masterPool,useDerived),existingPool,changedProducts));
      if (!useDerived) {
        update.setDerivedProductsChanged(checkForChangedDerivedProducts(masterPool,existingPool,changedProducts));
      }
      update.setOrderChanged(checkForOrderDataChanges(masterPool,helper,existingPool));
      update.setBrandingChanged(checkForBrandingChanges(masterPool,existingPool));
    }
    if (update.changed()) {
      poolsUpdated.add(update);
    }
 else {
      log.debug("String_Node_Str");
    }
  }
  return poolsUpdated;
}

Fixed version (ground truth):
public List<PoolUpdate> updatePools(Pool masterPool,List<Pool> existingPools,Long originalQuantity,Set<Product> changedProducts){
  log.debug("String_Node_Str" + masterPool);
  log.debug("String_Node_Str" + existingPools.size());
  PoolHelper helper=new PoolHelper(this.poolManager,null);
  List<PoolUpdate> poolsUpdated=new LinkedList<PoolUpdate>();
  Map<String,String> attributes=helper.getFlattenedAttributes(masterPool.getProduct());
  for (  Pool existingPool : existingPools) {
    log.debug("String_Node_Str" + existingPool.getId());
    if ("String_Node_Str".equalsIgnoreCase(existingPool.getSubscriptionSubKey())) {
      existingPool.setUpstreamPoolId(masterPool.getUpstreamPoolId());
      existingPool.setUpstreamEntitlementId(masterPool.getUpstreamEntitlementId());
      existingPool.setUpstreamConsumerId(masterPool.getUpstreamConsumerId());
      existingPool.setCdn(masterPool.getCdn());
      existingPool.setCertificate(masterPool.getCertificate());
    }
    PoolUpdate update=new PoolUpdate(existingPool);
    update.setDatesChanged(checkForDateChange(masterPool.getStartDate(),masterPool.getEndDate(),existingPool));
    update.setQuantityChanged(checkForQuantityChange(masterPool,existingPool,originalQuantity,existingPools,attributes));
    if (!existingPool.isMarkedForDelete()) {
      boolean useDerived=BooleanUtils.toBoolean(existingPool.getAttributeValue("String_Node_Str")) && masterPool.getDerivedProduct() != null;
      update.setProductsChanged(checkForChangedProducts(useDerived ? masterPool.getDerivedProduct() : masterPool.getProduct(),getExpectedProvidedProducts(masterPool,useDerived),existingPool,changedProducts));
      if (!useDerived) {
        update.setDerivedProductsChanged(checkForChangedDerivedProducts(masterPool,existingPool,changedProducts));
      }
      update.setOrderChanged(checkForOrderDataChanges(masterPool,helper,existingPool));
      update.setBrandingChanged(checkForBrandingChanges(masterPool,existingPool));
    }
    if (update.changed()) {
      poolsUpdated.add(update);
    }
 else {
      log.debug("String_Node_Str");
    }
  }
  return poolsUpdated;
}