From a99af17e2f94cdcbed0fee8bc9a183fdd6b1c7bc Mon Sep 17 00:00:00 2001
From: Marina Samuel <msamuel@mozilla.com>
Date: Fri, 20 Mar 2015 17:46:24 -0400
Subject: [PATCH] Bug 1145410: Return valid results when querying the provider
 cache while it's empty or being populated. r=adw

---
 toolkit/modules/NewTabUtils.jsm               | 12 ++++++++--
 .../tests/xpcshell/test_NewTabUtils.js        | 23 +++++++++++++++++++
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/toolkit/modules/NewTabUtils.jsm b/toolkit/modules/NewTabUtils.jsm
index 2c41fdd3ba4..e8d9030c861 100644
--- a/toolkit/modules/NewTabUtils.jsm
+++ b/toolkit/modules/NewTabUtils.jsm
@@ -1253,11 +1253,19 @@ this.NewTabUtils = {
   },
 
   getProviderLinks: function(aProvider) {
-    return Links._providers.get(aProvider).sortedLinks;
+    let cache = Links._providers.get(aProvider);
+    if (cache && cache.sortedLinks) {
+      return cache.sortedLinks;
+    }
+    return [];
   },
 
   isTopSiteGivenProvider: function(aSite, aProvider) {
-    return Links._providers.get(aProvider).siteMap.has(aSite);
+    let cache = Links._providers.get(aProvider);
+    if (cache && cache.siteMap) {
+      return cache.siteMap.has(aSite);
+    }
+    return false;
   },
 
   isTopPlacesSite: function(aSite) {
diff --git a/toolkit/modules/tests/xpcshell/test_NewTabUtils.js b/toolkit/modules/tests/xpcshell/test_NewTabUtils.js
index af0e857f651..fa87b788ccb 100644
--- a/toolkit/modules/tests/xpcshell/test_NewTabUtils.js
+++ b/toolkit/modules/tests/xpcshell/test_NewTabUtils.js
@@ -16,6 +16,29 @@ function run_test() {
   run_next_test();
 }
 
+add_task(function validCacheMidPopulation() {
+  let expectedLinks = makeLinks(0, 3, 1);
+
+  let provider = new TestProvider(done => done(expectedLinks));
+  provider.maxNumLinks = expectedLinks.length;
+
+  NewTabUtils.initWithoutProviders();
+  NewTabUtils.links.addProvider(provider);
+  let promise = new Promise(resolve => NewTabUtils.links.populateCache(resolve));
+
+  // isTopSiteGivenProvider() and getProviderLinks() should still return results
+  // even when cache is empty or being populated.
+  do_check_false(NewTabUtils.isTopSiteGivenProvider("example1.com", provider));
+  do_check_links(NewTabUtils.getProviderLinks(provider), []);
+
+  yield promise;
+
+  // Once the cache is populated, we get the expected results
+  do_check_true(NewTabUtils.isTopSiteGivenProvider("example1.com", provider));
+  do_check_links(NewTabUtils.getProviderLinks(provider), expectedLinks);
+  NewTabUtils.links.removeProvider(provider);
+});
+
 add_task(function notifyLinkDelete() {
   let expectedLinks = makeLinks(0, 3, 1);