https://issues.apache.org/jira/browse/AMQ-4248 - ensure iter is cleared when we are done, i.e. on call to release

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@1431660 13f79535-47bb-0310-9956-ffa450edef68

activemq-broker/src/main/java/org/apache/activemq/broker/region/cursors/FilePendingMessageCursor.java

@@ -148,6 +148,8 @@ public class FilePendingMessageCursor extends AbstractPendingMessageCursor imple
                 flushToDisk();
             }
         }
+        // ensure any memory ref is released
+        iter = null;
     }
 
     @Override

activemq-core/src/test/java/org/apache/activemq/broker/region/cursors/FilePendingMessageCursorTestSupport.java

@@ -26,10 +26,9 @@ import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-
-import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 public class FilePendingMessageCursorTestSupport {
 
@@ -70,4 +69,21 @@ public class FilePendingMessageCursorTestSupport {
         assertFalse("cursor is not full", underTest.isFull());
     }
 
+    @Test
+    public void testResetClearsIterator() throws Exception {
+        createBrokerWithTempStoreLimit();
+
+        underTest = new FilePendingMessageCursor(brokerService.getBroker(), "test", false);
+        // ok to add
+        underTest.addMessageLast(QueueMessageReference.NULL_MESSAGE);
+
+        underTest.reset();
+        underTest.release();
+
+        try {
+            underTest.hasNext();
+            fail("expect npe on use of iterator after release");
+        } catch (NullPointerException expected) {}
+    }
+
 }