Working around a bug in the IBM JVM which might cause a NPE in test tear down (FTPSERVER-422)

git-svn-id: https://svn.apache.org/repos/asf/mina/ftpserver/trunk@1138754 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/core/src/test/java/org/apache/ftpserver/clienttests/ClientTestTemplate.java b/core/src/test/java/org/apache/ftpserver/clienttests/ClientTestTemplate.java
index 6ec9608..aad9d52 100644
--- a/core/src/test/java/org/apache/ftpserver/clienttests/ClientTestTemplate.java
+++ b/core/src/test/java/org/apache/ftpserver/clienttests/ClientTestTemplate.java
@@ -227,7 +227,12 @@
         }
 
         if (server != null) {
-            server.stop();
+        	try {
+        		server.stop();
+        	} catch(NullPointerException e) {
+        		// a bug in the IBM JVM might cause Thread.interrupt() to throw an NPE
+        		// see http://www-01.ibm.com/support/docview.wss?uid=swg1IZ52037&wv=1
+        	}
         }
 
         cleanTmpDirs();