From d0ca0e09842221ac8c587eda8c0c25aff61dd6f2 Mon Sep 17 00:00:00 2001
From: George Mount <mount@google.com>
Date: Tue, 29 Mar 2016 10:32:56 -0700
Subject: [PATCH] Ensure window has been added in isTopOfTask

Bug 27893230

When isTopOfTask is called prior to the window being added, it
will throw an IllegalArgumentException. This checks that the
window has been added before making the call.

Change-Id: Idd14c0f1051e16d96a0a1fa9f990f380a1f69911
---
 core/java/android/app/Activity.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/core/java/android/app/Activity.java b/core/java/android/app/Activity.java
index 887932a7dbbb8..0d387e660f8ab 100644
--- a/core/java/android/app/Activity.java
+++ b/core/java/android/app/Activity.java
@@ -5920,6 +5920,9 @@ public class Activity extends ContextThemeWrapper
      * @return true if this is the topmost, non-finishing activity in its task.
      */
     private boolean isTopOfTask() {
+        if (mToken == null || mWindow == null || !mWindowAdded) {
+            return false;
+        }
         try {
             return ActivityManagerNative.getDefault().isTopOfTask(mToken);
         } catch (RemoteException e) {