Bug 1766764 - Make nsEditingSession::RemoveListenersAndControllers …

…forget the used listener if it succeeded removing it from the editor r=m_kato

Although it's called multiple times is odd that but it should not try to
remove same listener after once it succeeded doing it.  Note that the listener
is created before calling `AddTransactionListener` so that it should be no
problem to make it forget the removed listener.

Differential Revision: https://phabricator.services.mozilla.com/D144906

editor/composer/nsEditingSession.cpp

@@ -441,11 +441,13 @@ void nsEditingSession::RemoveListenersAndControllers(
   }
 
   // Remove all the listeners
+  RefPtr<ComposerCommandsUpdater> composertCommandsUpdater =
+      std::move(mComposerCommandsUpdater);
+  MOZ_ASSERT(!mComposerCommandsUpdater);
   aHTMLEditor->SetComposerCommandsUpdater(nullptr);
-  DebugOnly<bool> removedTransactionListener =
-      aHTMLEditor->RemoveTransactionListener(*mComposerCommandsUpdater);
-  NS_WARNING_ASSERTION(removedTransactionListener,
-                       "Failed to remove transaction listener from the editor");
+  if (!aHTMLEditor->RemoveTransactionListener(*composertCommandsUpdater)) {
+    NS_WARNING("Failed to remove transaction listener from the editor");
+  }
 
   // Remove editor controllers from the window now that we're not
   // editing in that window any more.