From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Selim Cinek <cinek@google.com>
Date: Fri, 5 May 2017 14:45:11 -0700
Subject: [PATCH] Fixed a concurrent modification crash

Test: runtest -x packages/SystemUI/tests/src/com/android/systemui/settings/CurrentUserTrackerTest.java
Change-Id: I23261843b7366d3a66a795a41c61b7661f7ca3a6
Fixes: 38006784

[syphyr: Backport to LineageOS 14.1: implement the actual fix only -
without exposing private members for testing visibility]
Signed-off-by: syphyr <syphyr@gmail.com>
Change-Id: Iceb22cc9d93f893e12def6b4e6d2b8cfba9a1b9f
---
 .../com/android/systemui/settings/CurrentUserTracker.java | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/settings/CurrentUserTracker.java b/packages/SystemUI/src/com/android/systemui/settings/CurrentUserTracker.java
index 005206fcd14c..90d8b61b9157 100644
--- a/packages/SystemUI/src/com/android/systemui/settings/CurrentUserTracker.java
+++ b/packages/SystemUI/src/com/android/systemui/settings/CurrentUserTracker.java
@@ -105,8 +105,12 @@ public abstract class CurrentUserTracker {
         private void notifyUserSwitched(int newUserId) {
             if (mCurrentUserId != newUserId) {
                 mCurrentUserId = newUserId;
-                for (Consumer<Integer> consumer : mCallbacks) {
-                    consumer.accept(newUserId);
+                List<Consumer<Integer>> callbacks = new ArrayList<>(mCallbacks);
+                for (Consumer<Integer> consumer : callbacks) {
+                    // Accepting may modify this list
+                    if (mCallbacks.contains(consumer)) {
+                        consumer.accept(newUserId);
+                    }
                 }
             }
         }