From 7a1721ad71a17283ba98fd3d30759f7158afc08a Mon Sep 17 00:00:00 2001
From: Beth Thibodeau <ethibodeau@google.com>
Date: Fri, 12 Jun 2020 12:36:18 -0400
Subject: [PATCH] Check connection state of media browser

We need to verify that the browser is actually connected before calling
getRoot or getSessionToken, otherwise it will throw an exception (and
crash sysui).

This is not typical but could happen if the service we connected to had
some problem and disconnected soon after we got the onConnected callback

Bug: 156104922
Test: atest com.android.systemui.media

Change-Id: I9b73e2167612a287b527c7bf7bdba1ca2455d55b
---
 .../systemui/media/ResumeMediaBrowser.java      | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/media/ResumeMediaBrowser.java b/packages/SystemUI/src/com/android/systemui/media/ResumeMediaBrowser.java
index 1e9a303646079..6462f072bc745 100644
--- a/packages/SystemUI/src/com/android/systemui/media/ResumeMediaBrowser.java
+++ b/packages/SystemUI/src/com/android/systemui/media/ResumeMediaBrowser.java
@@ -135,12 +135,16 @@ public class ResumeMediaBrowser {
          */
         @Override
         public void onConnected() {
+            Log.d(TAG, "Service connected for " + mComponentName);
             if (mMediaBrowser.isConnected()) {
-                mCallback.onConnected();
-                Log.d(TAG, "Service connected for " + mComponentName);
                 String root = mMediaBrowser.getRoot();
-                mMediaBrowser.subscribe(root, mSubscriptionCallback);
+                if (!TextUtils.isEmpty(root)) {
+                    mCallback.onConnected();
+                    mMediaBrowser.subscribe(root, mSubscriptionCallback);
+                    return;
+                }
             }
+            mCallback.onError();
         }
 
         /**
@@ -193,6 +197,10 @@ public class ResumeMediaBrowser {
                     @Override
                     public void onConnected() {
                         Log.d(TAG, "Connected for restart " + mMediaBrowser.isConnected());
+                        if (!mMediaBrowser.isConnected()) {
+                            mCallback.onError();
+                            return;
+                        }
                         MediaSession.Token token = mMediaBrowser.getSessionToken();
                         MediaController controller = new MediaController(mContext, token);
                         controller.getTransportControls();
@@ -251,7 +259,8 @@ public class ResumeMediaBrowser {
                     @Override
                     public void onConnected() {
                         Log.d(TAG, "connected");
-                        if (TextUtils.isEmpty(mMediaBrowser.getRoot())) {
+                        if (!mMediaBrowser.isConnected()
+                                || TextUtils.isEmpty(mMediaBrowser.getRoot())) {
                             mCallback.onError();
                         } else {
                             mCallback.onConnected();