From 27e1d35bcecc63fe4fdcd66785a0d9ad4c5d7a08 Mon Sep 17 00:00:00 2001
From: Guus der Kinderen <guus.der.kinderen@gmail.com>
Date: Fri, 10 Oct 2025 11:52:51 +0200
Subject: [PATCH] SPARK-2369: Prevent NPE in User-has-joined event

---
 .../main/java/org/jivesoftware/spark/ui/ChatContainer.java    | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/core/src/main/java/org/jivesoftware/spark/ui/ChatContainer.java b/core/src/main/java/org/jivesoftware/spark/ui/ChatContainer.java
index 43bcdfa0..c19afc27 100644
--- a/core/src/main/java/org/jivesoftware/spark/ui/ChatContainer.java
+++ b/core/src/main/java/org/jivesoftware/spark/ui/ChatContainer.java
@@ -956,7 +956,9 @@ public class ChatContainer extends SparkTabbedPane implements MessageListener, C
                 -> {
             for (final ChatRoomListener listener : chatRoomListeners) {
                 try {
-                    listener.userHasJoined(room, userid.toString());
+                    if (userid != null) {
+                        listener.userHasJoined(room, userid.toString());
+                    }
                 } catch (Exception e) {
                     Log.error("A ChatRoomListener (" + listener + ") threw an exception while processing a 'user joined' event for user '" + userid + "' in room: " + room, e);
                 }