[jboss-jira] [JBoss JIRA] Closed: (JBRULES-722) NullPointerException when using inserAfter method with an empty LinkedList

NullPointerException when using inserAfter method with an empty LinkedList -------------------------------------------------------------------------- Key: JBRULES-722 URL: http://jira.jboss.com/jira/browse/JBRULES-722 Project: JBoss Rules Issue Type: Bug Security Level: Public(Everyone can see) Affects Versions: 3.1-m1 Environment: Windows, jdk 1.5 Reporter: Pierre Paysant-Le Roux Assigned To: Edson Tirelli Fix For: 3.1-m2 JBoss rules throws a NullPointerException when adding my rules file. The problem is with the inserAfter methode in LinkedList. Debug shows that it appends when inserting a node in an empty list. I wrote a simple test case to illustrate the problem : Index: drools-core/src/test/java/org/drools/util/LinkedListTest.java =================================================================== --- drools-core/src/test/java/org/drools/util/LinkedListTest.java (revision 9968) +++ drools-core/src/test/java/org/drools/util/LinkedListTest.java (working copy) @@ -264,4 +264,7 @@ 3 ); } -} \ No newline at end of file + public void testInsertAfter(){ + this.list.insertAfter( null, this.node1 ); + } +} And a patch to avoid the problem : Index: drools-core/src/main/java/org/drools/util/LinkedList.java =================================================================== --- drools-core/src/main/java/org/drools/util/LinkedList.java (revision 9968) +++ drools-core/src/main/java/org/drools/util/LinkedList.java (working copy) @@ -151,17 +151,21 @@ } if ( existingNode == null ) { - // if existing node is null, then insert it as a first node - final LinkedListNode node = this.firstNode; - node.setPrevious( newNode ); - newNode.setNext( node ); - this.firstNode = newNode; + if(this.isEmpty()) + this.firstNode = newNode; + this.lastNode = newNode; + else{ + // if existing node is null, then insert it as a first node + final LinkedListNode node = this.firstNode; + node.setPrevious( newNode ); + newNode.setNext( node ); + this.firstNode = newNode; + } } else if ( existingNode == this.lastNode ) { existingNode.setNext(newNode); newNode.setPrevious( existingNode ); this.lastNode = newNode; } else { - ((LinkedListNode)existingNode.getNext()).setPrevious( newNode ); + ((LinkedListNode)existingNode.getNext()).setPrevious( newNode ); newNode.setNext( existingNode.getNext() ); existingNode.setNext( newNode ); newNode.setPrevious( existingNode ); Excuse me if I'm wrong.