Drools #Watch not working with accumulate in code - jboss

Question

I'm using Drools 7.6 and for some reason #watch doesn't stop the rule from reactivating itself or other rules when only the unwatched property is changed. Which results in an infinite loop.
Can someone figure out what am I doing wrong?
The rule:
package com.model
import com.model.*;
import java.util.List;
rule "10% for 15 High-range Items"
when
$o: Order($lines: orderLines) #watch(!discount)
Number(intValue >= 15) from accumulate(
OrderLine($item: item, $q: quantity) from $lines and
Item(category == Item.Category.HIGH_RANGE) from $item,
sum($q)
)
then
modify($o) {increaseDiscount(0.10)}
end
The model used is from the book Mastering JBoss Drools. The method increase discount has been annotated with #Modifes. The order class:
public class Order implements Serializable {
private static final long serialVersionUID = 1L;
private Long orderId;
private Date date;
private Customer customer;
private List<OrderLine> orderLines = new ArrayList<>();
private Discount discount;
public Order() {
}
public Long getOrderId() {
return orderId;
}
public void setOrderId(Long orderId) {
this.orderId = orderId;
}
public Customer getCustomer() {
return customer;
}
public void setCustomer(Customer customer) {
this.customer = customer;
}
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date = date;
}
public List<OrderLine> getOrderLines() {
return orderLines;
}
public void setItems(List<OrderLine> orderLines) {
this.orderLines = orderLines;
}
public double getTotal() {
return this.getOrderLines().stream()
.mapToDouble(item -> item.getItem().getSalePrice() * item.getQuantity())
.sum();
}
public int getTotalItems() {
return this.getOrderLines().stream()
.mapToInt(item -> item.getQuantity())
.sum();
}
#Modifies({"discount"})
public void increaseDiscount(double increase) {
if (discount == null) {
discount = new Discount(0.0);
}
discount.setPercentage(discount.getPercentage() + increase);
}
public Discount getDiscount() {
return discount;
}
public double getDiscountPercentage() {
return discount.getPercentage();
}
public void setDiscount(Discount discount) {
this.discount = discount;
}
}

Answer 1

I reported the problem here https://issues.jboss.org/browse/DROOLS-2427 and already pushed a fix on Drools master branch. Thanks for having reported this.

Answer 2

'from' is not reactive, so it cannot react to any modify changes.