From a1af0493780344ed2be130a4dd7a2be38949be6b Mon Sep 17 00:00:00 2001
From: Vania Januar <vanjan@google.com>
Date: Thu, 27 Apr 2023 15:51:13 +0100
Subject: [PATCH] Guard against null input device in StylusDeviceUpdater

Bug: 279170207
Test: StylusDeviceUpdaterTest
Change-Id: Ib4a3f12eaceb87370c800a9dc7eda819c706cd3b
---
 .../stylus/StylusDeviceUpdater.java           |  9 ++++++++-
 .../stylus/StylusDeviceUpdaterTest.java       | 19 +++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/com/android/settings/connecteddevice/stylus/StylusDeviceUpdater.java b/src/com/android/settings/connecteddevice/stylus/StylusDeviceUpdater.java
index da6e1789b0c..947c5acc83b 100644
--- a/src/com/android/settings/connecteddevice/stylus/StylusDeviceUpdater.java
+++ b/src/com/android/settings/connecteddevice/stylus/StylusDeviceUpdater.java
@@ -100,6 +100,8 @@ public class StylusDeviceUpdater implements InputManager.InputDeviceListener,
     @Override
     public void onInputDeviceAdded(int deviceId) {
         InputDevice inputDevice = mInputManager.getInputDevice(deviceId);
+        if (inputDevice == null) return;
+
         if (inputDevice.supportsSource(InputDevice.SOURCE_STYLUS)
                 && !inputDevice.isExternal()) {
             try {
@@ -121,7 +123,10 @@ public class StylusDeviceUpdater implements InputManager.InputDeviceListener,
 
     @Override
     public void onInputDeviceChanged(int deviceId) {
-        if (mInputManager.getInputDevice(deviceId).supportsSource(InputDevice.SOURCE_STYLUS)) {
+        InputDevice inputDevice = mInputManager.getInputDevice(deviceId);
+        if (inputDevice == null) return;
+
+        if (inputDevice.supportsSource(InputDevice.SOURCE_STYLUS)) {
             forceUpdate();
         }
     }
@@ -189,6 +194,8 @@ public class StylusDeviceUpdater implements InputManager.InputDeviceListener,
     boolean hasConnectedBluetoothStylusDevice() {
         for (int deviceId : mInputManager.getInputDeviceIds()) {
             InputDevice device = mInputManager.getInputDevice(deviceId);
+            if (device == null) continue;
+
             if (device.supportsSource(InputDevice.SOURCE_STYLUS)
                     && mInputManager.getInputDeviceBluetoothAddress(deviceId) != null) {
                 return true;
diff --git a/tests/robotests/src/com/android/settings/connecteddevice/stylus/StylusDeviceUpdaterTest.java b/tests/robotests/src/com/android/settings/connecteddevice/stylus/StylusDeviceUpdaterTest.java
index 7fb17e2eb2c..afdbb8beba2 100644
--- a/tests/robotests/src/com/android/settings/connecteddevice/stylus/StylusDeviceUpdaterTest.java
+++ b/tests/robotests/src/com/android/settings/connecteddevice/stylus/StylusDeviceUpdaterTest.java
@@ -26,6 +26,7 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
 
 import android.content.Context;
 import android.content.Intent;
@@ -108,6 +109,15 @@ public class StylusDeviceUpdaterTest {
                 any());
     }
 
+    @Test
+    public void onInputDeviceAdded_null_doesNothing() {
+        doReturn(null).when(mInputManager).getInputDevice(0);
+        mStylusDeviceUpdater.onInputDeviceAdded(0);
+
+        verify(mInputManager).getInputDevice(0);
+        verifyNoMoreInteractions(mInputManager);
+    }
+
     @Test
     public void onInputDeviceAdded_internalStylus_registersBatteryListener() {
         mStylusDeviceUpdater.onInputDeviceAdded(1);
@@ -124,6 +134,15 @@ public class StylusDeviceUpdaterTest {
                 any());
     }
 
+    @Test
+    public void onInputDeviceChanged_null_doesNothing() {
+        doReturn(null).when(mInputManager).getInputDevice(0);
+        mStylusDeviceUpdater.onInputDeviceChanged(0);
+
+        verify(mInputManager).getInputDevice(0);
+        verifyNoMoreInteractions(mInputManager);
+    }
+
     @Test
     public void click_usiPreference_launchUsiDetailsPage() {
         doReturn(mSettingsActivity).when(mDashboardFragment).getContext();