Crashes

app/src/main/java/chat/rocket/android/fragment/chatroom/RoomPresenter.java

@@ -152,8 +152,10 @@ public class RoomPresenter extends BasePresenter<RoomContract.View>
   @Override
   public void onMarkAsRead() {
     final Disposable subscription = roomRepository.getById(roomId)
+        .filter(Optional::isPresent)
+        .map(Optional::get)
         .firstElement()
-        .filter(room -> room != null && room.isAlert())
+        .filter(Room::isAlert)
         .subscribeOn(AndroidSchedulers.from(BackgroundLooper.get()))
         .observeOn(AndroidSchedulers.mainThread())
         .subscribe(
@@ -167,6 +169,8 @@ public class RoomPresenter extends BasePresenter<RoomContract.View>
   private void getRoomInfo() {
     final Disposable subscription = roomRepository.getById(roomId)
         .distinctUntilChanged()
+        .filter(Optional::isPresent)
+        .map(Optional::get)
         .subscribeOn(AndroidSchedulers.from(BackgroundLooper.get()))
         .observeOn(AndroidSchedulers.mainThread())
         .subscribe(
@@ -198,6 +202,8 @@ public class RoomPresenter extends BasePresenter<RoomContract.View>
 
   private void getMessages() {
     final Disposable subscription = roomRepository.getById(roomId)
+        .filter(Optional::isPresent)
+        .map(Optional::get)
         .flatMap(messageInteractor::getAllFrom)
         .subscribeOn(AndroidSchedulers.from(BackgroundLooper.get()))
         .observeOn(AndroidSchedulers.mainThread())
@@ -238,6 +244,8 @@ public class RoomPresenter extends BasePresenter<RoomContract.View>
 
   private Single<Room> getSingleRoom() {
     return roomRepository.getById(roomId)
+        .filter(Optional::isPresent)
+        .map(Optional::get)
         .firstElement()
         .toSingle();
   }

app/src/main/java/chat/rocket/android/layouthelper/chatroom/dialog/RoomUserAdapter.java

@@ -9,6 +9,7 @@ import android.view.ViewGroup;
 import java.util.List;
 import chat.rocket.android.R;
 import chat.rocket.android.helper.TextUtils;
+import chat.rocket.core.models.User;
 import chat.rocket.persistence.realm.models.ddp.RealmUser;
 import chat.rocket.persistence.realm.RealmHelper;
 import chat.rocket.android.renderer.UserRenderer;
@@ -47,16 +48,19 @@ public class RoomUserAdapter extends RecyclerView.Adapter<RoomUserViewHolder> {
       return;
     }
 
-    RealmUser user = realmHelper.executeTransactionForRead(realm ->
+    RealmUser realmUser = realmHelper.executeTransactionForRead(realm ->
         realm.where(RealmUser.class).equalTo(RealmUser.USERNAME, username).findFirst());
-    if (user == null) {
-      user = new RealmUser();
-      user.setUsername(username);
-      new UserRenderer(context, user.asUser())
+    if (realmUser == null) {
+      User user = User.builder()
+          .setId("some-local-is")
+          .setUsername(username)
+          .setUtcOffset(0)
+          .build();
+      new UserRenderer(context, user)
           .avatarInto(holder.avatar, hostname)
           .usernameInto(holder.username);
     } else {
-      new UserRenderer(context, user.asUser())
+      new UserRenderer(context, realmUser.asUser())
           .statusColorInto(holder.status)
           .avatarInto(holder.avatar, hostname)
           .usernameInto(holder.username);

persistence-realm/src/main/java/chat/rocket/persistence/realm/repositories/RealmMessageRepository.java

@@ -117,8 +117,7 @@ public class RealmMessageRepository extends RealmRepository implements MessageRe
           .equalTo(RealmMessage.ID, message.getId())
           .findAll()
           .<RealmResults<RealmMessage>>asObservable())
-          .filter(realmObject -> realmObject != null
-              && realmObject.isLoaded() && realmObject.isValid())
+          .filter(realmObject -> realmObject.isLoaded() && realmObject.isValid())
           .firstElement()
           .toSingle()
           .flatMap(realmMessages -> Single.just(realmMessages.deleteAllFromRealm()))

persistence-realm/src/main/java/chat/rocket/persistence/realm/repositories/RealmRoomRepository.java

@@ -44,20 +44,36 @@ public class RealmRoomRepository extends RealmRepository implements RoomReposito
   }
 
   @Override
-  public Flowable<Room> getById(String roomId) {
+  public Flowable<Optional<Room>> getById(String roomId) {
     return Flowable.defer(() -> Flowable.using(
         () -> new Pair<>(RealmStore.getRealm(hostname), Looper.myLooper()),
-        pair -> RxJavaInterop.toV2Flowable(
-            pair.first.where(RealmRoom.class)
+        pair -> {
+          RealmRoom realmRoom = pair.first.where(RealmRoom.class)
               .equalTo(RealmRoom.ROOM_ID, roomId)
-                .findFirst()
+              .findFirst();
+
+          if (realmRoom == null) {
+            return Flowable.just(Optional.<RealmRoom>absent());
+          }
+
+          return RxJavaInterop.toV2Flowable(
+              realmRoom
                   .<RealmRoom>asObservable()
-                .filter(roomSubscription -> roomSubscription != null && roomSubscription.isLoaded()
-                    && roomSubscription.isValid())),
+                  .filter(
+                      roomSubscription -> roomSubscription.isLoaded()
+                          && roomSubscription.isValid())
+                  .map(Optional::of));
+        },
         pair -> close(pair.first, pair.second)
     )
         .unsubscribeOn(AndroidSchedulers.from(Looper.myLooper()))
-        .map(RealmRoom::asRoom));
+        .map(optional -> {
+          if (optional.isPresent()) {
+            return Optional.of(optional.get().asRoom());
+          }
+
+          return Optional.absent();
+        }));
   }
 
   @Override

rocket-chat-core/src/main/java/chat/rocket/core/repositories/RoomRepository.java

@@ -12,7 +12,7 @@ public interface RoomRepository {
 
   Flowable<List<Room>> getAll();
 
-  Flowable<Room> getById(String roomId);
+  Flowable<Optional<Room>> getById(String roomId);
 
   Flowable<Optional<RoomHistoryState>> getHistoryStateByRoomId(String roomId);