PhabricatorApplicationTransactionCommentView performs $uri = id(new PhutilURI('/login/'))->replaceQueryParam('next', (string)$this->getRequestURI()) but the constructor call in PhabricatorEditEngine does not set any RequestURI so the Log In to Comment button at the bottom of an object view does not redirect back to the object URI after login.
Thus pass a RequestURI to PhabricatorApplicationTransactionCommentView in the constructor call in PhabricatorEditEngine.
Closes T15837