sync: Improve handling of bad UniquePos (retry)

sync/syncable/directory_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sync/syncable/directory_unittest.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/test/values_test_util.h"
 #include "sync/internal_api/public/base/attachment_id_proto.h"
 #include "sync/syncable/syncable_proto_util.h"
@@ skipping 63 matching lines @@
   // performance benefits of not writing to disk.
   dir_.reset(
       new Directory(new TestDirectoryBackingStore(kDirectoryName, &connection_),
                     &handler_,
                     NULL,
                     NULL,
                     NULL));
 
   DirOpenResult open_result =
       dir_->Open(kDirectoryName, &delegate_, NullTransactionObserver());
+
+  if (open_result != OPENED) {
+    dir_.reset();
+  }
+
   return open_result;
 }
 
 // Creates an empty entry and sets the ID field to a default one.
 void SyncableDirectoryTest::CreateEntry(const ModelType& model_type,
                                         const std::string& entryname) {
   CreateEntry(model_type, entryname, TestIdFactory::FromNumber(-99));
 }
 
 // Creates an empty entry and sets the ID field to id.
@@ skipping 1120 matching lines @@
 
   {
     ReadTransaction trans(FROM_HERE, dir().get());
 
     Entry null_ordinal_child(&trans, GET_BY_ID, null_child_id);
     EXPECT_TRUE(null_pos.Equals(null_ordinal_child.GetUniquePosition()));
     EXPECT_TRUE(null_pos.Equals(null_ordinal_child.GetServerUniquePosition()));
   }
 }
 
+// Any item with BOOKMARKS in their local specifics should have a valid local
+// unique position.  If there is an item in the loaded DB that does not match
+// this criteria, we consider the whole DB to be corrupt.
+TEST_F(SyncableDirectoryTest, BadPositionCountsAsCorruption) {
+  TestIdFactory id_factory;
+
+  {
+    WriteTransaction trans(FROM_HERE, UNITTEST, dir().get());
+
+    MutableEntry parent(&trans, CREATE, BOOKMARKS, id_factory.root(), "parent");
+    parent.PutIsDir(true);
+    parent.PutIsUnsynced(true);
+
+    // The code is littered with DCHECKs that try to stop us from doing what
+    // we're about to do.  Our work-around is to create a bookmark based on
+    // a server update, then update its local specifics without updating its
+    // local unique position.
+
+    MutableEntry child(
+        &trans, CREATE_NEW_UPDATE_ITEM, id_factory.MakeServer("child"));
+    sync_pb::EntitySpecifics specifics;
+    AddDefaultFieldValue(BOOKMARKS, &specifics);
+    child.PutIsUnappliedUpdate(true);
+    child.PutSpecifics(specifics);
+
+    EXPECT_TRUE(child.ShouldMaintainPosition());
+    EXPECT_TRUE(!child.GetUniquePosition().IsValid());
+  }
+
+  EXPECT_EQ(FAILED_DATABASE_CORRUPT, SimulateSaveAndReloadDir());
+}
+
 TEST_F(SyncableDirectoryTest, General) {
   int64 written_metahandle;
   const Id id = TestIdFactory::FromNumber(99);
   std::string name = "Jeff";
   // Test simple read operations on an empty DB.
   {
     ReadTransaction rtrans(FROM_HERE, dir().get());
     Entry e(&rtrans, GET_BY_ID, id);
     ASSERT_FALSE(e.good());  // Hasn't been written yet.
 
@@ skipping 400 matching lines @@
   // Delete the second entry, reload the Directory, see that the attachment is
   // no loner linked.
   DeleteEntry(id2);
   SimulateSaveAndReloadDir();
   ASSERT_FALSE(dir()->IsAttachmentLinked(attachment_id_proto));
 }
 
 }  // namespace syncable
 
 }  // namespace syncer