From 61f353983979845b64e37f98c9a7c7ced2e92800 Mon Sep 17 00:00:00 2001
From: Daniel Gultsch <daniel@gultsch.de>
Date: Sat, 2 Dec 2017 17:48:54 +0100
Subject: [PATCH] MAM: do not use private messages when finding last id in muc

---
 .../java/eu/siacs/conversations/entities/Conversation.java   | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/main/java/eu/siacs/conversations/entities/Conversation.java b/src/main/java/eu/siacs/conversations/entities/Conversation.java
index cce8a7468..c0af689a6 100644
--- a/src/main/java/eu/siacs/conversations/entities/Conversation.java
+++ b/src/main/java/eu/siacs/conversations/entities/Conversation.java
@@ -840,7 +840,10 @@ public class Conversation extends AbstractEntity implements Blockable, Comparabl
 		MamReference lastReceived = new MamReference(0);
 		synchronized (this.messages) {
 			for(int i = this.messages.size() - 1; i >= 0; --i) {
-				Message message = this.messages.get(i);
+				final Message message = this.messages.get(i);
+				if (message.getType() == Message.TYPE_PRIVATE) {
+					continue; //it's unsafe to use private messages as anchor. They could be coming from user archive
+				}
 				if (message.getStatus() == Message.STATUS_RECEIVED || message.isCarbon() || message.getServerMsgId() != null) {
 					lastReceived = new MamReference(message.getTimeSent(),message.getServerMsgId());
 					break;