nsIContent *parent; c->GetParent(parent); c = dont_AddRef(parent);
nsCOMPtr<nsIContent> parent; c->GetParent(getter_AddRefs(parent)); c.swap(parent);
EventTargetIn(nsIPresContext *aPresContext, nsEvent *aEvent,              nsIContent *aChild, nsIContent *aStop){  nsCOMPtr<nsIEventStateManager> esm;  aPresContext->GetEventStateManager(getter_AddRefs(esm));  nsCOMPtr<nsIContent> c;  esm->GetEventTargetContent(aEvent, getter_AddRefs(c));  while (c) {    if (c == aChild) {      return PR_TRUE;    }    if (c == aStop) {      break;    }    nsIContent *parent;    c->GetParent(parent);    c = dont_AddRef(parent);  }  return PR_FALSE;}