Fix handling of undeletion within the syncer.

chrome/browser/sync/engine/build_commit_command.cc

 // Copyright (c) 2006-2009 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 "chrome/browser/sync/engine/build_commit_command.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 74 matching lines @@
 
 void BuildCommitCommand::ExecuteImpl(SyncSession* session) {
   ClientToServerMessage message;
   message.set_share(session->context()->account_name());
   message.set_message_contents(ClientToServerMessage::COMMIT);
 
   CommitMessage* commit_message = message.mutable_commit();
   commit_message->set_cache_guid(
       session->write_transaction()->directory()->cache_guid());
   AddExtensionsActivityToMessage(session, commit_message);
+  SyncerProtoUtil::AddRequestBirthday(
+      session->write_transaction()->directory(), &message);
 
   const vector<Id>& commit_ids = session->status_controller()->commit_ids();
   for (size_t i = 0; i < commit_ids.size(); i++) {
     Id id = commit_ids[i];
     SyncEntity* sync_entry =
         static_cast<SyncEntity*>(commit_message->add_entries());
     sync_entry->set_id(id);
     MutableEntry meta_entry(session->write_transaction(),
                             syncable::GET_BY_ID,
                             id);
@@ skipping 13 matching lines @@
     // the |name| value (using |non_unique_name| instead), and will return
     // in the CommitResponse a unique name if one is generated.
     // We send both because it may aid in logging.
     sync_entry->set_non_unique_name(name);
 
     if (!meta_entry.Get(syncable::UNIQUE_CLIENT_TAG).empty()) {
       sync_entry->set_client_defined_unique_tag(
           meta_entry.Get(syncable::UNIQUE_CLIENT_TAG));
     }
 
-    // Deleted items with negative parent ids can be a problem so we set the
-    // parent to 0. (TODO(sync): Still true in protocol?).
+    // Deleted items with server-unknown parent ids can be a problem so we set
+    // the parent to 0. (TODO(sync): Still true in protocol?).
     Id new_parent_id;
     if (meta_entry.Get(syncable::IS_DEL) &&
         !meta_entry.Get(syncable::PARENT_ID).ServerKnows()) {
       new_parent_id = session->write_transaction()->root_id();
     } else {
       new_parent_id = meta_entry.Get(syncable::PARENT_ID);
     }
     sync_entry->set_parent_id(new_parent_id);
-    // TODO(sync): Investigate all places that think transactional commits
-    // actually exist.
-    //
-    // This is the only logic we'll need when transactional commits are moved
-    // to the server. If our parent has changes, send up the old one so the
-    // server can correctly deal with multiple parents.
+
+    // If our parent has changed, send up the old one so the server
+    // can correctly deal with multiple parents.
+    // TODO(nick): With the server keeping track of the primary sync parent,
+    // it should not be necessary to provide the old_parent_id: the version
+    // number should suffice.
     if (new_parent_id != meta_entry.Get(syncable::SERVER_PARENT_ID) &&
         0 != meta_entry.Get(syncable::BASE_VERSION) &&
         syncable::CHANGES_VERSION != meta_entry.Get(syncable::BASE_VERSION)) {
       sync_entry->set_old_parent_id(meta_entry.Get(syncable::SERVER_PARENT_ID));
     }
 
     int64 version = meta_entry.Get(syncable::BASE_VERSION);
     if (syncable::CHANGES_VERSION == version || 0 == version) {
-      // If this CHECK triggers during unit testing, check that we haven't
-      // altered an item that's an unapplied update.
-      CHECK(!id.ServerKnows()) << meta_entry;
+      // Undeletions are only supported for items that have a client tag.
+      DCHECK(!id.ServerKnows() ||
+             !meta_entry.Get(syncable::UNIQUE_CLIENT_TAG).empty())
+          << meta_entry;
+
+      // Version 0 means to create or undelete an object.
       sync_entry->set_version(0);
     } else {
-      CHECK(id.ServerKnows()) << meta_entry;
+      DCHECK(id.ServerKnows()) << meta_entry;
       sync_entry->set_version(meta_entry.Get(syncable::BASE_VERSION));
     }
     sync_entry->set_ctime(ClientTimeToServerTime(
         meta_entry.Get(syncable::CTIME)));
     sync_entry->set_mtime(ClientTimeToServerTime(
         meta_entry.Get(syncable::MTIME)));
 
     // Deletion is final on the server, let's move things and then delete them.
     if (meta_entry.Get(IS_DEL)) {
       sync_entry->set_deleted(true);
@@ skipping 10 matching lines @@
         // the new-style scheme, we should abandon the old way.
         SetOldStyleBookmarkData(&meta_entry, sync_entry);
       }
       SetEntrySpecifics(&meta_entry, sync_entry);
     }
   }
   session->status_controller()->mutable_commit_message()->CopyFrom(message);
 }
 
 }  // namespace browser_sync