From f5a1c69295bca579399cbb34fb21a988d2f76a10 Mon Sep 17 00:00:00 2001
From: Paul Zuehlcke <pbz@mozilla.com>
Date: Thu, 16 Dec 2021 16:38:54 +0000
Subject: [PATCH] Bug 1745959 - Do not fall back to selected browser in
 TabDialogBox getter. r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D133778
---
 browser/base/content/tabbrowser.js | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/browser/base/content/tabbrowser.js b/browser/base/content/tabbrowser.js
index 4f2bde31c3ab..8c6c4d382e58 100644
--- a/browser/base/content/tabbrowser.js
+++ b/browser/base/content/tabbrowser.js
@@ -866,11 +866,13 @@
     },
 
     getTabDialogBox(aBrowser) {
-      let browser = aBrowser || this.selectedBrowser;
-      if (!browser.tabDialogBox) {
-        browser.tabDialogBox = new TabDialogBox(browser);
+      if (!aBrowser) {
+        throw new Error("aBrowser is required");
       }
-      return browser.tabDialogBox;
+      if (!aBrowser.tabDialogBox) {
+        aBrowser.tabDialogBox = new TabDialogBox(aBrowser);
+      }
+      return aBrowser.tabDialogBox;
     },
 
     getTabFromAudioEvent(aEvent) {