Fix crash caused by multiple app launcher ordinal conflicts.

BUG=155603
TEST=Covered by unit test.

R=csharp@chromium.org


Review URL: https://chromiumcodereview.appspot.com/11154013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@162033 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 15 insertions, 1 deletions

diff --git a/chrome/browser/extensions/extension_sorting.cc b/chrome/browser/extensions/extension_sorting.cc
index 0be326b..48eea40 100644
--- a/chrome/browser/extensions/extension_sorting.cc
+++ b/chrome/browser/extensions/extension_sorting.cc
@@ -612,8 +612,15 @@ syncer::StringOrdinal ExtensionSorting::ResolveCollision(
   if (app_it == page.end())
     return app_launch_ordinal;
 
+  // Finds the next app launcher ordinal. This is done by the following loop
+  // because this function could be called before FixNTPOrdinalCollisions and
+  // thus |page| might contains multiple entries with the same app launch
+  // ordinal. See http://crbug.com/155603
+  while (app_it != page.end() && app_launch_ordinal.Equals(app_it->first))
+    ++app_it;
+
   // If there is no next after the collision, returns the next ordinal.
-  if (++app_it == page.end())
+  if (app_it == page.end())
     return app_launch_ordinal.CreateAfter();
 
   // Otherwise, returns the ordinal between the collision and the next ordinal.
diff --git a/chrome/browser/extensions/extension_sorting_unittest.cc b/chrome/browser/extensions/extension_sorting_unittest.cc
index 8158b90..201b62f 100644
--- a/chrome/browser/extensions/extension_sorting_unittest.cc
+++ b/chrome/browser/extensions/extension_sorting_unittest.cc
@@ -937,10 +937,17 @@ class ExtensionSortingDefaultOrdinalNoCollision
     extension_sorting->SetPageOrdinal(other_app_->id(), default_page_ordinal_);
     extension_sorting->SetAppLaunchOrdinal(other_app_->id(),
                                            default_app_launch_ordinal_);
+
+    yet_another_app_ = prefs_.AddApp("yet_aother_app");
+    extension_sorting->SetPageOrdinal(yet_another_app_->id(),
+                                      default_page_ordinal_);
+    extension_sorting->SetAppLaunchOrdinal(yet_another_app_->id(),
+                                           default_app_launch_ordinal_);
   }
 
  private:
   scoped_refptr<Extension> other_app_;
+  scoped_refptr<Extension> yet_another_app_;
 };
 TEST_F(ExtensionSortingDefaultOrdinalNoCollision,
        ExtensionSortingDefaultOrdinalNoCollision) {}