From f488523ee707233ce61e23b90d285c13943d7051 Mon Sep 17 00:00:00 2001
From: Hongwei Wang <hwwang@google.com>
Date: Thu, 2 Apr 2020 12:08:59 -0700
Subject: [PATCH] Fix NPE when removing PIP stack

Task#getDisplayArea is @Nullable and it happens when removing PIP stack.

Bug: 152798429
Test: atest --iteration 5 PinnedStackTests
Change-Id: Ie180df88d5705dce54f494913d226d9c0dc75f9a
---
 services/core/java/com/android/server/wm/ActivityStack.java | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/wm/ActivityStack.java b/services/core/java/com/android/server/wm/ActivityStack.java
index 10b335e583b0b..391571e3cd2f5 100644
--- a/services/core/java/com/android/server/wm/ActivityStack.java
+++ b/services/core/java/com/android/server/wm/ActivityStack.java
@@ -727,9 +727,13 @@ class ActivityStack extends Task {
     private void setWindowingModeInSurfaceTransaction(int preferredWindowingMode, boolean animate,
             boolean showRecents, boolean enteringSplitScreenMode, boolean deferEnsuringVisibility,
             boolean creating) {
+        final TaskDisplayArea taskDisplayArea = getDisplayArea();
+        if (taskDisplayArea == null) {
+            Slog.d(TAG, "taskDisplayArea is null, bail early");
+            return;
+        }
         final int currentMode = getWindowingMode();
         final int currentOverrideMode = getRequestedOverrideWindowingMode();
-        final TaskDisplayArea taskDisplayArea = getDisplayArea();
         final Task topTask = getTopMostTask();
         int windowingMode = preferredWindowingMode;
         if (preferredWindowingMode == WINDOWING_MODE_UNDEFINED