From 8ad79ffd15a30beb1e11d6cca07d8e3564df510a Mon Sep 17 00:00:00 2001
From: Winson Chung <winsonc@google.com>
Date: Wed, 1 Sep 2021 21:07:01 -0700
Subject: [PATCH] Fix NPE in edge back gesture handler

- TaskBarDelegate creates an EdgeBackGestureHandler, but does not set
  a stage change callback (not needed currently)

Fixes: 197831135
Test: atest SystemUITests

Signed-off-by: Winson Chung <winsonc@google.com>
Change-Id: I35841c077506d7dad35b0c53a72d9907c205cb52
---
 .../systemui/navigationbar/gestural/EdgeBackGestureHandler.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java b/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java
index aaa3bf0f40ee9..bf1a98fa39e65 100644
--- a/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java
+++ b/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java
@@ -384,7 +384,7 @@ public class EdgeBackGestureHandler extends CurrentUserTracker
     private void onNavigationSettingsChanged() {
         boolean wasBackAllowed = isHandlingGestures();
         updateCurrentUserResources();
-        if (wasBackAllowed != isHandlingGestures()) {
+        if (mStateChangeCallback != null && wasBackAllowed != isHandlingGestures()) {
             mStateChangeCallback.run();
         }
     }