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  1. Drools
  2. DROOLS-4288

Infinite recursion in drools after version change from v7.20 to v7.21

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Details

    • Bug
    • Resolution: Done
    • Major
    • 7.25.0.Final
    • 7.21.0.Final, 7.22.0.Final, 7.23.0.Final
    • core engine
    • None
    • 2019 Week 29-31
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      Steps to Reproduce are in the description

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      Steps to Reproduce are in the description
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    Description

      When there is a version change in drools-compiler from `7.20.0.Final` to `7.21.0.Final` some rules are looping recursively.

      Code in github:

      The working version

      The recursively looping version

      The change between working and looping version

      More details

      When I fire a rule whose `then` part modifies a fact that is already checked in the `when` part:

      rule "rule 1.1"
        when
          $sampleDomain: SampleDomain(instanceVariable2 == "Value of instance variable")
        then
          System.out.println("Rule 1.1 fired");
          modify($sampleDomain){
          		setInstanceVariable1(3)
          }
      end
      

      it doesn't loop recursively.

      But when I call another rule which call a static function from another class:

      rule "rule 1.2"
        when
          $sampleDomain: SampleDomain(CoreUtils.anotherFunction())
        then
          System.out.println("Rule 1.2 fired");
          modify($sampleDomain){
          		setInstanceVariable1(3)
          }
      end
      

      it loops recursively.

      The class with static function is

      import com.drool_issue.domain.SampleDomain;
      
      public class CoreUtils {
      	
      	public static boolean anotherFunction() {
      		System.out.println("anotherFunction() inside CoreUtils");
      		return true;
      	}
      	
      	public static boolean anotherFunction(SampleDomain sampleDomain) {
      		System.out.println("anotherFunction(SampleDomain sampleDomain) inside CoreUtils");
      		return true;
      	}
      
      }
      

      My domain file is:

      public class SampleDomain {
      	private int instanceVariable1;
      	private String instanceVariable2;
      	private int instanceVariable3;
      	
      	
      	public int getInstanceVariable1() {
      		return instanceVariable1;
      	}
      	public void setInstanceVariable1(int instanceVariable1) {
      		this.instanceVariable1 = instanceVariable1;
      	}
      	public String getInstanceVariable2() {
      		return instanceVariable2;
      	}
      	public void setInstanceVariable2(String instanceVariable2) {
      		this.instanceVariable2 = instanceVariable2;
      	}
      	public int getInstanceVariable3() {
      		return instanceVariable3;
      	}
      	public void setInstanceVariable3(int instanceVariable3) {
      		this.instanceVariable3 = instanceVariable3;
      	}
      	
      	
      
      }
      

      This is only caused after version change from `7.20.0.Final` to `7.21.0.Final`. Any guess on what the problem might be?

      When I further looked into the problem I saw this too.

      When we add two functions into the `SampleDomain` class ie

          public boolean anotherFunction() {
      		return true;
      	}
      	
      	public boolean anotherFunction(SampleDomain sampleDomain) {
      		return true;
      	}
      

      and use this in the rule like:

      rule "rule 1.4"
        when
          $sampleDomain: SampleDomain(anotherFunction())
        then
          System.out.println("Rule 1.4 fired");
          modify($sampleDomain){
          		setInstanceVariable1(3)
          }
      end
      

      and

      rule "rule 1.5"
        when
          $sampleDomain: SampleDomain(anotherFunction($sampleDomain))
        then
          System.out.println("Rule 1.5 fired");
          modify($sampleDomain){
          		setInstanceVariable3(4)
          }
      end
      

      these also loops recursively.

      Code in github:

      The recursive looping when using non static methods

      The change between working and above version

      Also when any of the static method is made non static then method from the domain class is called even though the static method is specified in the rule.

      Code portions to be noted here are:

      Rule where static method is called.

      Another rule which also call the static method.

      The static access modifier removed from the functions which where previously static.

      Code in github:

      Weird behaviour when removing static modifier for the functions.

      The change between working and above version

      All this are caused in versions after `7.20.0.Final`, ie `7.21.0.Final`, `7.22.0.Final` and `7.23.0.Final`

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          Geogie Tom

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              mfusco@redhat.com Mario Fusco
              geogietom Geogie Tom (Inactive)
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                Updated:
                Resolved: