[NTP4] Fix empty apps page crash.

chrome/browser/extensions/extension_sorting_unittest.cc

Index: chrome/browser/extensions/extension_sorting_unittest.cc
diff --git a/chrome/browser/extensions/extension_sorting_unittest.cc b/chrome/browser/extensions/extension_sorting_unittest.cc
index ed309f1ba2f507fae19992e730aee77162527280..ed16f6875ab984f8427ee63332e5b4a0686828dc 100644
--- a/chrome/browser/extensions/extension_sorting_unittest.cc
+++ b/chrome/browser/extensions/extension_sorting_unittest.cc
@@ -685,7 +685,7 @@ class ExtensionSortingGetMinOrMaxAppLaunchOrdinalsOnPage :
 TEST_F(ExtensionSortingGetMinOrMaxAppLaunchOrdinalsOnPage,
        ExtensionSortingGetMinOrMaxAppLaunchOrdinalsOnPage) {}
 
-// Make sure that empty pages aren't removes from the integer to ordinal
+// Make sure that empty pages aren't removed from the integer to ordinal
 // mapping. See http://www.crbug.com/109802 for details.
 class ExtensionSortingKeepEmptyStringOrdinalPages :
     public ExtensionSortingPreinstalledAppsBase {
@@ -725,3 +725,35 @@ class ExtensionSortingKeepEmptyStringOrdinalPages :
 };
 TEST_F(ExtensionSortingKeepEmptyStringOrdinalPages,
        ExtensionSortingKeepEmptyStringOrdinalPages) {}
+
+class ExtensionSortingMakesFillerOrdinals :
+    public ExtensionSortingPreinstalledAppsBase {
+ public:
+  ExtensionSortingMakesFillerOrdinals() {}
+  virtual ~ExtensionSortingMakesFillerOrdinals() {}
+
+  virtual void Initialize() {
+    ExtensionSorting* extension_sorting = prefs()->extension_sorting();
+
+    StringOrdinal first_page = StringOrdinal::CreateInitialOrdinal();
+    extension_sorting->SetPageOrdinal(app1_->id(), first_page);
+    EXPECT_EQ(0, extension_sorting->PageStringOrdinalAsInteger(first_page));
+  }
+  virtual void Verify() {
+    ExtensionSorting* extension_sorting = prefs()->extension_sorting();
+
+    // Because the UI can add an unlimited number of empty pages without an app
+    // on them, this test simulates dropping of an app on the 1st and 4th empty
+    // pages (3rd and 6th pages by index) to ensure we don't crash and that
+    // filler ordinals are created as needed. See: http://crbug.com/122214
+    StringOrdinal page_three = extension_sorting->PageIntegerAsStringOrdinal(2);
+    extension_sorting->SetPageOrdinal(app1_->id(), page_three);
+    EXPECT_EQ(2, extension_sorting->PageStringOrdinalAsInteger(page_three));
+
+    StringOrdinal page_six = extension_sorting->PageIntegerAsStringOrdinal(5);
+    extension_sorting->SetPageOrdinal(app1_->id(), page_six);
+    EXPECT_EQ(5, extension_sorting->PageStringOrdinalAsInteger(page_six));
+  }
+};
+TEST_F(ExtensionSortingMakesFillerOrdinals,
+       ExtensionSortingMakesFillerOrdinals) {}