Bug 1415918

                                       nullptr);
     mInPermitUnload = false;
   }

   nsCOMPtr<nsIDocShell> docShell(mContainer);
   nsAutoString text;
   event->GetReturnValue(text);

-  if (*aPermitUnloadFlags == eDontPromptAndDontUnload && !text.IsEmpty()) {
-    *aPermitUnload = false;
-    return NS_OK;
-  }
-
   if (sIsBeforeUnloadDisabled) {
     *aPermitUnloadFlags = eDontPromptAndUnload;
   }

   // NB: we nullcheck mDocument because it might now be dead as a result of
   // the event being dispatched.
-  if (*aPermitUnloadFlags == ePrompt && dialogsAreEnabled &&
+  if ((*aPermitUnloadFlags != eDontPromptAndUnload) && dialogsAreEnabled &&
       mDocument && !(mDocument->GetSandboxFlags() & SANDBOXED_MODALS) &&
       (!sBeforeUnloadRequiresInteraction || mDocument->UserHasInteracted()) &&
       (event->WidgetEventPtr()->DefaultPrevented() || !text.IsEmpty())) {
+
+    if (*aPermitUnloadFlags == eDontPromptAndDontUnload) {
+      *aPermitUnload = false;
+      return NS_OK;
+    }
+
     // Ask the user if it's ok to unload the current page

     nsCOMPtr<nsIPrompt> prompt = do_GetInterface(docShell);

     if (prompt) {
       nsCOMPtr<nsIWritablePropertyBag2> promptBag = do_QueryInterface(prompt);
       if (promptBag) {
         bool isTabModalPromptAllowed;