Return an empty list when the requested node is not in the tree

This change makes it so a request for the data in a folder that doesn't
exist always returns promptly. Prior to this, all requests would hang
indefinitely instead.

This is only a stand in for a future solution to send a null result
through the media framework instead. Unfortunately, our structure needs
some tweaking to make that work. This will be fine for the interim.

Bug: 148604797
Test: Build, flash, browse deep into a tree, switch players to invalid
that parents of the node you're on, try browsing upward. See that we
return an empty list for all missing nodes.

Change-Id: Ifd5ed106d3b46377f0d7cd2d1e565cde45ab06f9
Merged-In: Ifd5ed106d3b46377f0d7cd2d1e565cde45ab06f9

1 files changed, 3 insertions, 1 deletions

diff --git a/src/com/android/bluetooth/avrcpcontroller/AvrcpControllerService.java b/src/com/android/bluetooth/avrcpcontroller/AvrcpControllerService.java
index 693b4a291..56684cd7c 100644
--- a/src/com/android/bluetooth/avrcpcontroller/AvrcpControllerService.java
+++ b/src/com/android/bluetooth/avrcpcontroller/AvrcpControllerService.java
@@ -172,9 +172,11 @@ public class AvrcpControllerService extends ProfileService {
             }
         }
 
+        // If we don't find a node in the tree then do not have any way to browse for the contents.
+        // Return an empty list instead.
         if (requestedNode == null) {
             if (DBG) Log.d(TAG, "Didn't find a node");
-            return null;
+            return new ArrayList(0);
         } else {
             if (!requestedNode.isCached()) {
                 if (DBG) Log.d(TAG, "node is not cached");