Bug 1383599 - browser.newtabpage.enabled = false is not working. r=ursula

MozReview-Commit-ID: HUBr10vb9qJ

--HG--
extra : rebase_source : 222994b1f0f808985a5963dcb6cf1e1ea1bba097

browser/app/profile/firefox.js

@@ -1257,8 +1257,7 @@ pref("prompts.tab_modal.enabled", true);
 // Activates preloading of the new tab url.
 pref("browser.newtab.preload", true);
 
-// Is supposed to toggle something to do with about:newtab . Doesn't seem to do
-// anything in activity stream. bug 1443646 covers dealing with this.
+// Indicates if about:newtab shows content (enabled) or just blank
 pref("browser.newtabpage.enabled", true);
 
 // Activity Stream prefs that control to which page to redirect

browser/components/about/AboutRedirector.cpp

@@ -21,6 +21,8 @@ namespace browser {
 
 NS_IMPL_ISUPPORTS(AboutRedirector, nsIAboutModule)
 
+bool AboutRedirector::sNewTabPageEnabled = false;
+
 struct RedirEntry {
   const char* id;
   const char* url;
@@ -133,12 +135,21 @@ AboutRedirector::NewChannel(nsIURI* aURI,
   nsCOMPtr<nsIIOService> ioService = do_GetIOService(&rv);
   NS_ENSURE_SUCCESS(rv, rv);
 
+  static bool sNTPEnabledCacheInited = false;
+  if (!sNTPEnabledCacheInited) {
+    Preferences::AddBoolVarCache(&AboutRedirector::sNewTabPageEnabled,
+                                 "browser.newtabpage.enabled");
+    sNTPEnabledCacheInited = true;
+  }
+
   for (auto & redir : kRedirMap) {
     if (!strcmp(path.get(), redir.id)) {
       nsAutoCString url;
 
-      if (path.EqualsLiteral("newtab") || path.EqualsLiteral("home")) {
-        // let the aboutNewTabService decide where to redirect
+      // Let the aboutNewTabService decide where to redirect for about:home and
+      // enabled about:newtab. Disabled about:newtab page uses fallback.
+      if (path.EqualsLiteral("home") ||
+          (sNewTabPageEnabled && path.EqualsLiteral("newtab"))) {
         nsCOMPtr<nsIAboutNewTabService> aboutNewTabService =
           do_GetService("@mozilla.org/browser/aboutnewtab-service;1", &rv);
         NS_ENSURE_SUCCESS(rv, rv);

browser/components/about/AboutRedirector.h

@@ -24,6 +24,9 @@ public:
 
 protected:
   virtual ~AboutRedirector() {}
+
+private:
+  static bool sNewTabPageEnabled;
 };
 
 } // namespace browser

browser/components/newtab/aboutNewTabService.js

@@ -15,7 +15,6 @@ ChromeUtils.defineModuleGetter(this, "AboutNewTab",
 
 // Dummy references to the files that this service no longer allows loading.
 // Bug 1409054 to remove "chrome://browser/content/abouthome/aboutHome.xhtml"
-// Bug 1433133 to remove "chrome://browser/content/newtab/newTab.xhtml"
 
 const TOPIC_APP_QUIT = "quit-application-granted";
 const TOPIC_LOCALES_CHANGE = "intl:requested-locales-changed";

browser/components/newtab/tests/browser/browser.ini

@@ -1,6 +1,7 @@
 [DEFAULT]
 
 [browser_activity_stream_strings.js]
+[browser_enabled_newtabpage.js]
 [browser_packaged_as_locales.js]
 skip-if=true # bug 1423703 comment 20
 [browser_newtab_overrides.js]

browser/components/newtab/tests/browser/browser_enabled_newtabpage.js

@@ -0,0 +1,21 @@
+ChromeUtils.import("resource://gre/modules/NetUtil.jsm");
+
+function checkSpec(uri, check, message) {
+  const {spec} = NetUtil.newChannel({
+    loadUsingSystemPrincipal: true,
+    uri
+  }).URI;
+
+  info(`got ${spec} for ${uri}`);
+  check(spec, "about:blank", message);
+}
+
+add_task(async function test_newtab_enabled() {
+  checkSpec("about:newtab", isnot, "did not get blank for default about:newtab");
+  checkSpec("about:home", isnot, "did not get blank for default about:home");
+
+  await SpecialPowers.pushPrefEnv({set: [["browser.newtabpage.enabled", false]]});
+
+  checkSpec("about:newtab", is, "got blank when newtab is not enabled");
+  checkSpec("about:home", isnot, "still did not get blank for about:home");
+});