From 827375d5f89c2b5dc41b267afa22a15c6c4aca76 Mon Sep 17 00:00:00 2001
From: "J. Ryan Stinnett" <jryans@gmail.com>
Date: Wed, 27 May 2015 20:17:18 -0500
Subject: [PATCH] Bug 1168095 - Repair view source from sidebar pages. r=Gijs

---
 browser/base/content/browser.js       | 12 ++++++++++--
 browser/base/content/nsContextMenu.js | 12 ++++++++++--
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 60c1a4498cfc..e666b0b1f38c 100644
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -2363,11 +2363,19 @@ function BrowserViewSourceOfDocument(aArgsOrDocument) {
   let inTab = Services.prefs.getBoolPref("view_source.tab");
   if (inTab) {
     let viewSourceURL = `view-source:${args.URL}`;
-    let tab = gBrowser.loadOneTab(viewSourceURL, {
+    let tabBrowser = gBrowser;
+    // In the case of sidebars and chat windows, gBrowser is defined but null,
+    // because no #content element exists.  For these cases, we need to find
+    // the most recent browser window.
+    if (!tabBrowser) {
+      let browserWindow = RecentWindow.getMostRecentBrowserWindow();
+      tabBrowser = browserWindow.gBrowser;
+    }
+    let tab = tabBrowser.loadOneTab(viewSourceURL, {
       relatedToCurrent: true,
       inBackground: false
     });
-    args.viewSourceBrowser = gBrowser.getBrowserForTab(tab);
+    args.viewSourceBrowser = tabBrowser.getBrowserForTab(tab);
     top.gViewSourceUtils.viewSourceInBrowser(args);
   } else {
     top.gViewSourceUtils.viewSource(args);
diff --git a/browser/base/content/nsContextMenu.js b/browser/base/content/nsContextMenu.js
index 18cb420b0d4d..71081326ca32 100644
--- a/browser/base/content/nsContextMenu.js
+++ b/browser/base/content/nsContextMenu.js
@@ -1007,11 +1007,19 @@ nsContextMenu.prototype = {
 
     let inTab = Services.prefs.getBoolPref("view_source.tab");
     if (inTab) {
-      let tab = gBrowser.loadOneTab("about:blank", {
+      let tabBrowser = gBrowser;
+      // In the case of sidebars and chat windows, gBrowser is defined but null,
+      // because no #content element exists.  For these cases, we need to find
+      // the most recent browser window.
+      if (!tabBrowser) {
+        let browserWindow = RecentWindow.getMostRecentBrowserWindow();
+        tabBrowser = browserWindow.gBrowser;
+      }
+      let tab = tabBrowser.loadOneTab("about:blank", {
         relatedToCurrent: true,
         inBackground: false
       });
-      let viewSourceBrowser = gBrowser.getBrowserForTab(tab);
+      let viewSourceBrowser = tabBrowser.getBrowserForTab(tab);
       if (aContext == "selection") {
         top.gViewSourceUtils
            .viewSourceFromSelectionInBrowser(reference, viewSourceBrowser);