Fixed a crash with DisposableTaskListFragment

astrid/src/com/todoroo/astrid/activity/DisposableTaskListFragment.java

@@ -26,7 +26,7 @@ public class DisposableTaskListFragment extends TaskListFragment {
             TaskListActivity tla = (TaskListActivity) activity;
             if (tla.getFragmentLayout() == AstridActivity.LAYOUT_SINGLE) {
                 TaskListFragmentPagerAdapter adapter = tla.getFragmentPagerAdapter();
-                if (adapter != null)
+                if (adapter != null && adapter.getPosition(filter) >= 0)
                     adapter.remove(filter);
             }
         }

astrid/src/com/todoroo/astrid/activity/TaskListActivity.java

@@ -374,6 +374,10 @@ public class TaskListActivity extends AstridActivity implements MainMenuListener
         setCommentsCount(0);
 
         if (swipeIsEnabled()) {
+            TaskListFragment currentFragment = getTaskListFragment();
+            if (currentFragment instanceof DisposableTaskListFragment) {
+                tlfPagerAdapter.remove(currentFragment.filter);
+            }
             TaskListFragmentPager.showSwipeBetweenHelper(this);
             tlfPager.showFilter((Filter) item);
             return true;

astrid/src/com/todoroo/astrid/adapter/TaskListFragmentPagerAdapter.java

@@ -74,6 +74,10 @@ public class TaskListFragmentPagerAdapter extends FragmentStatePagerAdapter impl
         return filterAdapter.addOrLookup(filter);
     }
 
+    public int getPosition(Filter filter) {
+        return filterAdapter.getPosition(filter);
+    }
+
     public void remove(Filter filter) {
         filterAdapter.remove(filter);
     }