Unsubscribe from typing observers when forwarding messages.

src/org/thoughtcrime/securesms/ConversationFragment.java

@@ -176,6 +176,12 @@ public class ConversationFragment extends Fragment
     this.listener = (ConversationFragmentListener)activity;
   }
 
+  @Override
+  public void onStart() {
+    super.onStart();
+    initializeTypingObserver();
+  }
+
   @Override
   public void onResume() {
     super.onResume();
@@ -185,6 +191,12 @@ public class ConversationFragment extends Fragment
     }
   }
 
+  @Override
+  public void onStop() {
+    super.onStop();
+    ApplicationContext.getInstance(requireContext()).getTypingStatusRepository().getTypists(threadId).removeObservers(this);
+  }
+
   public void onNewIntent() {
     if (actionMode != null) {
       actionMode.finish();
@@ -227,7 +239,6 @@ public class ConversationFragment extends Fragment
 
     OnScrollListener scrollListener = new ConversationScrollListener(getActivity());
     list.addOnScrollListener(scrollListener);
-    initializeTypingObserver();
   }
 
   private void initializeListAdapter() {