From 31e9ca615b326f5b46e58dbd3716fe5bbb0517ed Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Thu, 15 Apr 2021 19:41:07 +0800
Subject: [PATCH] Fix NPE if display is off and then removed

The additional display can be removed right after turning off.

Bug: 185460118
Test: Toggle display
Change-Id: I25d86e952f5e24f3165ce556b6435ba61b59f596
---
 .../java/com/android/server/wm/TaskSnapshotController.java  | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/wm/TaskSnapshotController.java b/services/core/java/com/android/server/wm/TaskSnapshotController.java
index 5ffab483202f0..a467d82b362e0 100644
--- a/services/core/java/com/android/server/wm/TaskSnapshotController.java
+++ b/services/core/java/com/android/server/wm/TaskSnapshotController.java
@@ -646,8 +646,12 @@ class TaskSnapshotController {
         if (shouldDisableSnapshots()) {
             return;
         }
+        final DisplayContent displayContent = mService.mRoot.getDisplayContent(displayId);
+        if (displayContent == null) {
+            return;
+        }
         mTmpTasks.clear();
-        mService.mRoot.getDisplayContent(displayId).forAllTasks(task -> {
+        displayContent.forAllTasks(task -> {
             // Since RecentsAnimation will handle task snapshot while switching apps with the best
             // capture timing (e.g. IME window capture), No need additional task capture while task
             // is controlled by RecentsAnimation.