Fix for sync bug 31566. Return const& rather than a copy from

syncable Blob accessor to avoid danger with assigning the return
value _address_ to a pointer (which was done by r34993).

BUG=31566
TEST=SyncableDirectoryTest.TestSimpleFieldsPreservedDuringSaveChanges

Review URL: http://codereview.chromium.org/527014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35676 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 22 insertions, 4 deletions

diff --git a/chrome/browser/sync/syncable/syncable.h b/chrome/browser/sync/syncable/syncable.h
index 6665bf7..d0562f5 100755
--- a/chrome/browser/sync/syncable/syncable.h
+++ b/chrome/browser/sync/syncable/syncable.h
@@ -237,11 +237,11 @@ struct EntryKernel {
   inline void mark_dirty() {
     dirty_ = true;
   }
-  
+
   inline void clear_dirty() {
     dirty_ = false;
   }
-  
+
   inline bool is_dirty() const {
     return dirty_;
   }
@@ -302,13 +302,13 @@ struct EntryKernel {
   inline const std::string& ref(StringField field) const {
     return string_fields[field - STRING_FIELDS_BEGIN];
   }
-  inline Blob ref(BlobField field) const {
+  inline const Blob& ref(BlobField field) const {
     return blob_fields[field - BLOB_FIELDS_BEGIN];
   }
   inline bool ref(BitTemp field) const {
     return bit_temps[field - BIT_TEMPS_BEGIN];
   }
-  
+
  private:
   // Tracks whether this entry needs to be saved to the database.
   bool dirty_;
diff --git a/chrome/browser/sync/syncable/syncable_unittest.cc b/chrome/browser/sync/syncable/syncable_unittest.cc
index 7012142..9d7b07b 100755
--- a/chrome/browser/sync/syncable/syncable_unittest.cc
+++ b/chrome/browser/sync/syncable/syncable_unittest.cc
@@ -627,6 +627,7 @@ TEST_F(SyncableDirectoryTest, TestSimpleFieldsPreservedDuringSaveChanges) {
   EntryKernel create_pre_save, update_pre_save;
   EntryKernel create_post_save, update_post_save;
   string create_name =  "Create";
+  string favicon_bytes = "PNG";
 
   {
     WriteTransaction trans(dir_.get(), UNITTEST, __FILE__, __LINE__);
@@ -634,11 +635,20 @@ TEST_F(SyncableDirectoryTest, TestSimpleFieldsPreservedDuringSaveChanges) {
     MutableEntry update(&trans, CREATE_NEW_UPDATE_ITEM, update_id);
     create.Put(IS_UNSYNCED, true);
     update.Put(IS_UNAPPLIED_UPDATE, true);
+    syncable::Blob fav(favicon_bytes.data(),
+                       favicon_bytes.data() + favicon_bytes.size());
+    create.Put(BOOKMARK_FAVICON, fav);
+    update.Put(BOOKMARK_FAVICON, fav);
     create_pre_save = create.GetKernelCopy();
     update_pre_save = update.GetKernelCopy();
     create_id = create.Get(ID);
   }
+
   dir_->SaveChanges();
+  dir_.reset(new Directory());
+  ASSERT_TRUE(dir_.get());
+  ASSERT_TRUE(OPENED == dir_->Open(file_path_, kName));
+  ASSERT_TRUE(dir_->good());
 
   {
     ReadTransaction trans(dir_.get(), __FILE__, __LINE__);
@@ -681,6 +691,14 @@ TEST_F(SyncableDirectoryTest, TestSimpleFieldsPreservedDuringSaveChanges) {
               update_post_save.ref((StringField)i))
               << "String field #" << i << " changed during save/load";
   }
+  for ( ; i < BLOB_FIELDS_END; ++i) {
+    EXPECT_EQ(create_pre_save.ref((BlobField)i),
+              create_post_save.ref((BlobField)i))
+              << "Blob field #" << i << " changed during save/load";
+    EXPECT_EQ(update_pre_save.ref((BlobField)i),
+              update_post_save.ref((BlobField)i))
+              << "Blob field #" << i << " changed during save/load";
+  }
 }
 
 TEST_F(SyncableDirectoryTest, TestSaveChangesFailure) {