From fe998eca06fc435dd4e53df902b8db6bf6f3f701 Mon Sep 17 00:00:00 2001
From: Kris Maglione <maglione.k@gmail.com>
Date: Sun, 21 Apr 2013 19:57:28 -0700
Subject: [PATCH] Fix harmless error when document is unloaded immediately
 after exiting hint mode.

---
 common/content/hints.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/common/content/hints.js b/common/content/hints.js
index 51b7ecfe..a9154e88 100644
--- a/common/content/hints.js
+++ b/common/content/hints.js
@@ -490,6 +490,10 @@ var HintSession = Class("HintSession", CommandMode, {
 
         let n = 5;
         (function next() {
+            if (Cu.isDeadWrapper && Cu.isDeadWrapper(elem))
+                // Hint document has been unloaded.
+                return;
+
             let hinted = n || this.validHints.some(function (h) h.elem === elem);
             if (!hinted)
                 hints.setClass(elem, null);