From 1e21ab763cfbfdb1925408fd4b9112a65ff6ded7 Mon Sep 17 00:00:00 2001
From: spslinger <3893604+spslinger@users.noreply.github.com>
Date: Thu, 11 Oct 2018 12:29:32 +0200
Subject: [PATCH] Fix getPresence ConcurrentModificationException

Fix for SMACK-841

Since Smack 4.2.4, the getPresencesInternal method in the Roster class
can return a LruCache object, which is a LinkedHashMap with access
order. This means that any access using get or getOrDefault will be a
modification of the Map. If you loop over the keySet of the Map and
there are more than one, the second call to get will throw a
ConcurrentModificationException!

Since the keys are only used here to obtain the corresponding
values, the simplest solution is to just loop over the values instead.
---
 .../src/main/java/org/jivesoftware/smack/roster/Roster.java    | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java b/smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java
index c4e7a0cf2..8e241151d 100644
--- a/smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java
+++ b/smack-im/src/main/java/org/jivesoftware/smack/roster/Roster.java
@@ -951,8 +951,7 @@ public final class Roster extends Manager {
             // This is used in case no available presence is found
             Presence unavailable = null;
 
-            for (Resourcepart resource : userPresences.keySet()) {
-                Presence p = userPresences.get(resource);
+            for (Presence p : userPresences.values()) {
                 if (!p.isAvailable()) {
                     unavailable = p;
                     continue;