[rules-users] Upgrading from 3.x to 4.0.7

[Knych, Thomas]

Hi -

I'm upgrading a large base of rules from 3.x to 4.0.7. However there
seem to be a few semantic differences. I have rules like the below in a
few places:

rule "All items should have a unique external id"
      when
                new_item : Item( exId : externalId )
		    old_item : Item( externalId == exId )
	then
		LOG.warn( "DUPE Detected: new:" +  new_item + " old:" +
old_item );
		retract( new_item );
end

And this all worked fine because 3.x would never assign the same object
to both new_item and old_item. I know my new/old seem arbitary - but I'm
just getting down to the minimal reproducing case. 4.x now will assign
one instance of an object to both new_item and old_item. Is there any
way to disable this behaviour?


thanks,
-Tom