MIDI: Add null check for UserManager.getMainUser

UserManager.getMainUser() can return null for some devices.
This is causing a NullPointerException in some automotive cases.

This CL adds an additional check to make sure that this is not null.

Bug: 322622902
Test: Connect to jamstick on phone with MIDI+BTLE app.
Test: Verify that MidiScope receives packets successfully.
Change-Id: I5b8e060cd8cafde1b1c60e259cc5ba0516a417d0

1 files changed, 5 insertions, 1 deletions

diff --git a/services/midi/java/com/android/server/midi/MidiService.java b/services/midi/java/com/android/server/midi/MidiService.java
index 39aaab25d7be..7402d1454bab 100644
--- a/services/midi/java/com/android/server/midi/MidiService.java
+++ b/services/midi/java/com/android/server/midi/MidiService.java
@@ -1011,7 +1011,11 @@ public class MidiService extends IMidiManager.Stub {
             }
         }
 
-        if (user.getUserIdentifier() == mUserManager.getMainUser().getIdentifier()) {
+        // Allow only the main user to create BluetoothMidiService.
+        // If there is no main user, allow all users to create it.
+        UserHandle mainUser = mUserManager.getMainUser();
+        if ((mainUser == null)
+                || (user.getUserIdentifier() == mainUser.getIdentifier())) {
             PackageInfo info;
             try {
                 info = mPackageManager.getPackageInfoAsUser(