From 97449fa389dbc1ab872d63fde001bae7a659991b Mon Sep 17 00:00:00 2001
From: Jeff Sharkey <jsharkey@android.com>
Date: Fri, 18 Nov 2016 11:05:18 -0700
Subject: [PATCH] Lists returned from OS aren't mutable.

Data returned via ParceledListSlice is a snapshot of data from the
system, and should not be mutated directly.

In particular, this can cause developer confusion if they call
Collection.remove(), which doesn't actually mutate the value in the
system.  There are other mutation APIs that developers should be
using instead, such as JobScheduler.cancel().

Test: builds, boots, common operations work
Bug: 27856974
Change-Id: I72528dee4d79e483aa295bd91d1ed80d0d72d21c
---
 core/java/android/content/pm/ParceledListSlice.java      | 9 ++++++++-
 .../systemui/recents/model/RecentsTaskLoadPlan.java      | 4 ++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/core/java/android/content/pm/ParceledListSlice.java b/core/java/android/content/pm/ParceledListSlice.java
index 945858e6d3c65..29ea5a07ee9b9 100644
--- a/core/java/android/content/pm/ParceledListSlice.java
+++ b/core/java/android/content/pm/ParceledListSlice.java
@@ -17,12 +17,15 @@
 package android.content.pm;
 
 import android.os.Binder;
+import android.os.Build;
 import android.os.IBinder;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.os.RemoteException;
 import android.util.Log;
 
+import dalvik.system.VMRuntime;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -127,7 +130,11 @@ public class ParceledListSlice<T extends Parcelable> implements Parcelable {
     }
 
     public List<T> getList() {
-        return mList;
+        if (VMRuntime.getRuntime().getTargetSdkVersion() > Build.VERSION_CODES.N_MR1) {
+            return Collections.unmodifiableList(mList);
+        } else {
+            return mList;
+        }
     }
 
     @Override
diff --git a/packages/SystemUI/src/com/android/systemui/recents/model/RecentsTaskLoadPlan.java b/packages/SystemUI/src/com/android/systemui/recents/model/RecentsTaskLoadPlan.java
index 9b48e4d02623c..5bfc17fcaaf96 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/model/RecentsTaskLoadPlan.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/model/RecentsTaskLoadPlan.java
@@ -104,8 +104,8 @@ public class RecentsTaskLoadPlan {
         int currentUserId = UserHandle.USER_CURRENT;
         updateCurrentQuietProfilesCache(currentUserId);
         SystemServicesProxy ssp = Recents.getSystemServices();
-        mRawTasks = ssp.getRecentTasks(ActivityManager.getMaxRecentTasksStatic(),
-                currentUserId, includeFrontMostExcludedTask, mCurrentQuietProfiles);
+        mRawTasks = new ArrayList<>(ssp.getRecentTasks(ActivityManager.getMaxRecentTasksStatic(),
+                currentUserId, includeFrontMostExcludedTask, mCurrentQuietProfiles));
 
         // Since the raw tasks are given in most-recent to least-recent order, we need to reverse it
         Collections.reverse(mRawTasks);