1) Update offline cache when user goes offline.

2) Use offline cache to figure out if we need to store offline info in the database.

git-svn-id: http://svn.igniterealtime.org/svn/repos/wildfire/trunk@6365 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/wildfire/spi/PresenceManagerImpl.java

@@ -232,6 +232,18 @@ public class PresenceManagerImpl extends BasicModule implements PresenceManager
             // Keep track of the time when the user went offline
             java.util.Date offlinePresenceDate = new java.util.Date();
 
+            boolean addedToCache;
+            if (offlinePresence == null) {
+                addedToCache = !NULL_STRING.equals(offlinePresenceCache.put(username, NULL_STRING));
+            }
+            else {
+                addedToCache = !offlinePresence.equals(offlinePresenceCache.put(username, offlinePresence));
+            }
+            if (!addedToCache) {
+                return;
+            }
+            lastActivityCache.put(username, offlinePresenceDate.getTime());
+
             // Insert data into the database.
             Connection con = null;
             PreparedStatement pstmt = null;