TrackRecordingManager: rather crash than try to load invalid data.

src/main/java/de/dennisguse/opentracks/services/TrackRecordingManager.java

@@ -131,6 +131,10 @@ public class TrackRecordingManager implements SharedPreferences.OnSharedPreferen
     }
 
     RecordingData getDataForUI() {
+        if (trackId == null) {
+            throw new RuntimeException("Requesting data if not recording should not be done.");
+        }
+
         Pair<TrackPoint, SensorDataSet> current = trackPointCreator.createCurrentTrackPoint(lastTrackPointUIWithSpeed, lastTrackPointUIWithAltitude, lastStoredTrackPointWithLocation);
         TrackPoint trackPoint = current.first;
         TrackStatisticsUpdater tmpTrackStatisticsUpdater = new TrackStatisticsUpdater(trackStatisticsUpdater, trackPoint);
@@ -139,8 +143,7 @@ public class TrackRecordingManager implements SharedPreferences.OnSharedPreferen
 
         Track track = contentProviderUtils.getTrack(trackId); //Get copy TODO: Avoid re-loading data from DB
         if (track == null) {
-            Log.w(TAG, "Requesting data if not recording is taking place, should not be done.");
-            return null;
+            throw new RuntimeException("Data could not be loaded for TrackId " + trackId);
         }
 
         TrackBuilder trackBuilder = new TrackBuilder(track);