From 4e6e52443de7a873f6f1a7b72b6f4ec6048f9880 Mon Sep 17 00:00:00 2001
From: hughchen <hughchen@google.com>
Date: Mon, 6 Apr 2020 11:42:33 +0800
Subject: [PATCH] Fix null point exception on LocalMediaManager

- Use TextUtils.equal() to check string compare.
- Add test case.

Bug: 153144708
Test: make -j42 RunSettingsLibRoboTests
Change-Id: Iabaf4bc86bcf353e1dd86269c7add7690bae0bfe
---
 .../settingslib/media/LocalMediaManager.java  |  4 ++--
 .../media/LocalMediaManagerTest.java          | 20 +++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/packages/SettingsLib/src/com/android/settingslib/media/LocalMediaManager.java b/packages/SettingsLib/src/com/android/settingslib/media/LocalMediaManager.java
index fb8a0b7f63ca6..b2774182bfa2e 100644
--- a/packages/SettingsLib/src/com/android/settingslib/media/LocalMediaManager.java
+++ b/packages/SettingsLib/src/com/android/settingslib/media/LocalMediaManager.java
@@ -220,7 +220,7 @@ public class LocalMediaManager implements BluetoothCallback {
      */
     public MediaDevice getMediaDeviceById(List<MediaDevice> devices, String id) {
         for (MediaDevice mediaDevice : devices) {
-            if (mediaDevice.getId().equals(id)) {
+            if (TextUtils.equals(mediaDevice.getId(), id)) {
                 return mediaDevice;
             }
         }
@@ -236,7 +236,7 @@ public class LocalMediaManager implements BluetoothCallback {
      */
     public MediaDevice getMediaDeviceById(String id) {
         for (MediaDevice mediaDevice : mMediaDevices) {
-            if (mediaDevice.getId().equals(id)) {
+            if (TextUtils.equals(mediaDevice.getId(), id)) {
                 return mediaDevice;
             }
         }
diff --git a/packages/SettingsLib/tests/robotests/src/com/android/settingslib/media/LocalMediaManagerTest.java b/packages/SettingsLib/tests/robotests/src/com/android/settingslib/media/LocalMediaManagerTest.java
index 1c690724b1c1d..d40c45cb78f8c 100644
--- a/packages/SettingsLib/tests/robotests/src/com/android/settingslib/media/LocalMediaManagerTest.java
+++ b/packages/SettingsLib/tests/robotests/src/com/android/settingslib/media/LocalMediaManagerTest.java
@@ -217,6 +217,26 @@ public class LocalMediaManagerTest {
         assertThat(device).isNull();
     }
 
+    @Test
+    public void getMediaDeviceById_idIsNull_shouldReturnNull() {
+        final MediaDevice device1 = mock(MediaDevice.class);
+        final MediaDevice device2 = mock(MediaDevice.class);
+        mLocalMediaManager.mMediaDevices.add(device1);
+        mLocalMediaManager.mMediaDevices.add(device2);
+
+        when(device1.getId()).thenReturn(null);
+        when(device2.getId()).thenReturn(null);
+
+        MediaDevice device = mLocalMediaManager
+                .getMediaDeviceById(mLocalMediaManager.mMediaDevices, TEST_CURRENT_DEVICE_ID);
+
+        assertThat(device).isNull();
+
+        device = mLocalMediaManager.getMediaDeviceById(TEST_CURRENT_DEVICE_ID);
+
+        assertThat(device).isNull();
+    }
+
     @Test
     public void onDeviceAdded_addDevice() {
         final MediaDevice device = mock(MediaDevice.class);