From 47dfb1b22cc3a76807b634ab7ffe490ffd151204 Mon Sep 17 00:00:00 2001
From: gorhill <rhill@raymondhill.net>
Date: Sat, 22 Jul 2017 16:57:29 -0400
Subject: [PATCH] fix https://github.com/uBlockOrigin/uAssets/issues/567

---
 platform/firefox/vapi-background.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/platform/firefox/vapi-background.js b/platform/firefox/vapi-background.js
index 7a85730ff..40157849f 100644
--- a/platform/firefox/vapi-background.js
+++ b/platform/firefox/vapi-background.js
@@ -680,6 +680,12 @@ var winWatcher = (function() {
         if ( !win || windowToIdMap.delete(win) !== true ) {
             return;
         }
+        // https://github.com/uBlockOrigin/uAssets/issues/567
+        //   We need to cleanup if and only if the window being closed is
+        //   the actual top window.
+        if ( win.gBrowser && win.gBrowser.ownerGlobal !== win ) {
+            return;
+        }
         if ( typeof api.onCloseWindow === 'function' ) {
             api.onCloseWindow(win);
         }