Group Chat History contains one message to many.

When specifying “Show a Specific Number of Messages” for Group Chat
History Settings, the user get one message to many. For example, if 10
is specified. the user get the last eleven messages in the room.

src/java/org/jivesoftware/openfire/muc/HistoryStrategy.java

@@ -197,7 +197,7 @@ public class HistoryStrategy {
                 // message because we want to preserve the room subject if
                 // possible.
                 Iterator<Message> historyIter = history.iterator();
-                while (historyIter.hasNext() && history.size() > strategyMaxNumber) {
+                while (historyIter.hasNext() && history.size() >= strategyMaxNumber) {
                     if (historyIter.next() != roomSubject) {
                         historyIter.remove();
                     }