Fix app crash due to improper construction of backstack

app/src/main/java/in/ac/iitb/gymkhana/iitbapp/MainActivity.java

@@ -258,7 +258,7 @@ public class MainActivity extends AppCompatActivity implements NavigationView.On
         if (bundle == null) {
             bundle = new Bundle();
         }
-        bundle.putString(SESSION_ID, session.pref.getString(SESSION_ID, "Error"));
+        bundle.putString(Constants.SESSION_ID, session.pref.getString(Constants.SESSION_ID, "Error"));
         fragment.setArguments(bundle);
         FragmentManager manager = getSupportFragmentManager();
         if (fragment instanceof FeedFragment)

app/src/main/java/in/ac/iitb/gymkhana/iitbapp/data/Converters.java

 package in.ac.iitb.gymkhana.iitbapp.data;
 
 import android.arch.persistence.room.TypeConverter;
+import android.util.Log;
 
 import com.google.gson.Gson;
+import com.google.gson.JsonSyntaxException;
 import com.google.gson.reflect.TypeToken;
 
 import java.lang.reflect.Type;
@@ -72,7 +74,13 @@ public class Converters {
 
     @TypeConverter
     public static Timestamp timestampfromString(String value) {
-        return new Gson().fromJson(value, Timestamp.class);
+        try {
+            return new Gson().fromJson(value, Timestamp.class);
+        } catch (JsonSyntaxException e) {
+            Log.d("Converters", "timestampfromString: " + value);
+            e.printStackTrace();
+            return null;
+        }
     }
 
     @TypeConverter

app/src/main/java/in/ac/iitb/gymkhana/iitbapp/fragment/FeedFragment.java

@@ -21,7 +21,6 @@ import java.util.List;
 import in.ac.iitb.gymkhana.iitbapp.ActivityBuffer;
 import in.ac.iitb.gymkhana.iitbapp.Constants;
 import in.ac.iitb.gymkhana.iitbapp.ItemClickListener;
-import in.ac.iitb.gymkhana.iitbapp.MainActivity;
 import in.ac.iitb.gymkhana.iitbapp.R;
 import in.ac.iitb.gymkhana.iitbapp.adapter.FeedAdapter;
 import in.ac.iitb.gymkhana.iitbapp.api.RetrofitInterface;
@@ -116,7 +115,7 @@ public class FeedFragment extends BaseFragment {
     }
 
     private void displayEvents(final List<Event> events) {
-        FeedAdapter feedAdapter = new FeedAdapter(events, new ItemClickListener() {
+        final FeedAdapter feedAdapter = new FeedAdapter(events, new ItemClickListener() {
             @Override
             public void onItemClick(View v, int position) {
                 String eventJson = new Gson().toJson(events.get(position));
@@ -129,17 +128,16 @@ public class FeedFragment extends BaseFragment {
                 FragmentManager manager = getActivity().getSupportFragmentManager();
                 FragmentTransaction transaction = manager.beginTransaction();
                 transaction.replace(R.id.framelayout_for_fragment, eventFragment, eventFragment.getTag());
-                transaction.commit();
+                transaction.addToBackStack(eventFragment.getTag()).commit();
             }
         });
         getActivityBuffer().safely(new ActivityBuffer.IRunnable() {
             @Override
             public void run(Activity pActivity) {
-                feedRecyclerView = pActivity.findViewById(R.id.feed_recycler_view);
+                feedRecyclerView = getActivity().findViewById(R.id.feed_recycler_view);
+                feedRecyclerView.setAdapter(feedAdapter);
+                feedRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
             }
         });
-        feedRecyclerView.setAdapter(feedAdapter);
-        feedRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
-
     }
 }