From 7326979bcdf0bfd85c46a0186b4eb025e8e695a5 Mon Sep 17 00:00:00 2001
From: Louis Chang <louischang@google.com>
Date: Tue, 9 Jun 2020 16:02:42 +0800
Subject: [PATCH] Prevent NPE while finishing activity

Activity was finished and removed from history before entering
global lock and caused NPE when accessing its task.

Bug: 158299941
Test: existing tests
Change-Id: Iac49bb631653137785edff48c46e2263adbbda64
---
 .../com/android/server/wm/ActivityTaskManagerService.java    | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index 5f591b54b067c..88b1ac31b26b3 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -1685,6 +1685,11 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
         final NeededUriGrants resultGrants = collectGrants(resultData, r.resultTo);
 
         synchronized (mGlobalLock) {
+            // Sanity check in case activity was removed before entering global lock.
+            if (!r.isInHistory()) {
+                return true;
+            }
+
             // Keep track of the root activity of the task before we finish it
             final Task tr = r.getTask();
             final ActivityRecord rootR = tr.getRootActivity();