call rpc.start() before it is used

src/main/java/com/b44t/messenger/rpc/Rpc.java

@@ -17,6 +17,7 @@ public class Rpc {
     private final Map<Integer, SettableFuture<JsonElement>> requestFutures = new ConcurrentHashMap<>();
     private final DcJsonrpcInstance dcJsonrpcInstance;
     private int requestId = 0;
+    private boolean started = false;
     private final Gson gson = new GsonBuilder().serializeNulls().create();
 
     public Rpc(DcJsonrpcInstance dcJsonrpcInstance) {
@@ -46,6 +47,7 @@ public class Rpc {
     }
 
     public void start() {
+        started = true;
         new Thread(() -> {
             while (true) {
                 try {
@@ -57,7 +59,9 @@ public class Rpc {
         }, "jsonrpcThread").start();
     }
 
-    public SettableFuture<JsonElement> call(String method, Object... params) {
+    public SettableFuture<JsonElement> call(String method, Object... params) throws RpcException {
+        if (!started) throw new RpcException("RPC not started yet.");
+
         int id;
         synchronized (this) {
             id = ++requestId;

src/main/java/org/thoughtcrime/securesms/ApplicationContext.java

@@ -88,6 +88,7 @@ public class ApplicationContext extends MultiDexApplication {
 
     dcAccounts = new DcAccounts(new File(getFilesDir(), "accounts").getAbsolutePath());
     rpc = new Rpc(dcAccounts.getJsonrpcInstance());
+    rpc.start();
     AccountManager.getInstance().migrateToDcAccounts(this);
     int[] allAccounts = dcAccounts.getAll();
     for (int accountId : allAccounts) {
@@ -126,8 +127,6 @@ public class ApplicationContext extends MultiDexApplication {
       Log.i("DeltaChat", "shutting down event handler");
     }, "eventThread").start();
 
-    rpc.start();
-
     // migrating global notifications pref. to per-account config, added  10/July/24
     final String NOTIFICATION_PREF = "pref_key_enable_notifications";
     boolean isMuted = !Prefs.getBooleanPreference(this, NOTIFICATION_PREF, true);