From d12ed5520e5501207baf8089a5f1711cd06d863d Mon Sep 17 00:00:00 2001
From: Chris Rebert <code@chrisrebert.com>
Date: Tue, 22 Dec 2015 23:02:57 -0700
Subject: [PATCH] Modal: Ignore spurious `focus` event that Firefox fires at
 `document` when switching back to its tab

Fixes #18365
Refs https://bugzilla.mozilla.org/show_bug.cgi?id=1228802
---
 js/src/modal.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/js/src/modal.js b/js/src/modal.js
index d408850201..202c5fe94c 100644
--- a/js/src/modal.js
+++ b/js/src/modal.js
@@ -259,8 +259,9 @@ const Modal = (($) => {
       $(document)
         .off(Event.FOCUSIN) // guard against infinite focus loop
         .on(Event.FOCUSIN, (event) => {
-          if (this._element !== event.target &&
-             (!$(this._element).has(event.target).length)) {
+          if (document !== event.target &&
+              this._element !== event.target &&
+              (!$(this._element).has(event.target).length)) {
             this._element.focus()
           }
         })
-- 
2.47.2