Restore logic for identifying resources to request to include authori…

…ties for which the currentCpc is a fallback server from the desired one.

Remove added whitespace and unnecessary check for xdsclient being shutdown (won't be called if cpc .

xds/src/main/java/io/grpc/xds/client/XdsClient.java

@@ -402,7 +402,7 @@ void handleResourceResponse(
     void handleStreamClosed(Status error, boolean shouldTryFallback);
 
     /** Called when the ADS stream has established communication with the xds server.
-     * Is expected do manage the ControlPlanClients and cache updates associated with
+     * Is expected to manage the ControlPlanClients and cache updates associated with
      * Moving to or from a fallback server.
      *
      * <p>Must be synchronized.

xds/src/main/java/io/grpc/xds/client/XdsClientImpl.java

@@ -185,7 +185,11 @@ public Collection<String> getSubscribedResources(
       return null;
     }
 
-    Collection<String> authorities = getActiveAuthorities(targetCpc);
+    // This should include all of the authorities that targetCpc or a fallback from it is serving
+    List<String> authorities = activatedCpClients.entrySet().stream()
+        .filter(entry -> entry.getValue().contains(targetCpc))
+        .map(Map.Entry::getKey)
+        .collect(Collectors.toList());
 
     Map<String, ResourceSubscriber<? extends ResourceUpdate>> resources =
         resourceSubscribers.getOrDefault(type, Collections.emptyMap());
@@ -987,10 +991,6 @@ public void handleStreamClosed(Status status, boolean shouldTryFallback) {
     public void handleStreamRestarted(ServerInfo serverInfo) {
       syncContext.throwIfNotInThisSynchronizationContext();
 
-      if (isShutDown()) {
-        return;
-      }
-
       ControlPlaneClient controlPlaneClient = serverCpClientMap.get(serverInfo);
       if (controlPlaneClient == null) {
         return;

xds/src/main/java/io/grpc/xds/client/XdsTransportFactory.java

@@ -36,7 +36,6 @@ <ReqT, RespT> StreamingCall<ReqT, RespT> createStreamingCall(
          MethodDescriptor.Marshaller<RespT> respMarshaller);
 
     void shutdown();
-
   }
 
   /**