Fixed NPE when stopping the server while users are connected. JM-177

git-svn-id: http://svn.igniterealtime.org/svn/repos/messenger/trunk@998 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/messenger/SessionManager.java

@@ -607,8 +607,9 @@ public class SessionManager extends BasicModule {
      * @return the <code>Session</code> associated with the JID.
      */
     public ClientSession getSession(JID from) {
-        // Return null if the JID is null or belongs to a foreign server
-        if (from == null || !serverName.equals(from.getDomain())) {
+        // Return null if the JID is null or belongs to a foreign server. If the server is
+        // shutting down then serverName will be null so answer null too in this case.
+        if (from == null || serverName == null || !serverName.equals(from.getDomain())) {
             return null;
         }