From cf42d60c5309ba946ed67af508f242ba714b32a9 Mon Sep 17 00:00:00 2001
From: Steven Moreland <smoreland@google.com>
Date: Fri, 30 Dec 2022 02:39:14 +0000
Subject: [PATCH] unregistered null callback will cause a crash later

Bug: N/A
Change-Id: I7acbc084d8a401817879d416f0283ca40e060069
Test: N/A
---
 .../src/com/android/networkstack/tethering/Tethering.java      | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Tethering/src/com/android/networkstack/tethering/Tethering.java b/Tethering/src/com/android/networkstack/tethering/Tethering.java
index b3ec805565..e1b7016658 100644
--- a/Tethering/src/com/android/networkstack/tethering/Tethering.java
+++ b/Tethering/src/com/android/networkstack/tethering/Tethering.java
@@ -2407,6 +2407,9 @@ public class Tethering {
 
     /** Unregister tethering event callback */
     void unregisterTetheringEventCallback(ITetheringEventCallback callback) {
+        if (callback == null) {
+            throw new NullPointerException();
+        }
         mHandler.post(() -> {
             mTetheringEventCallbacks.unregister(callback);
         });