Update next_id when loading sync DB

sync/syncable/directory.cc

 // Copyright (c) 2012 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.h"
 
 #include "base/debug/trace_event.h"
 #include "base/perftimer.h"
 #include "base/stl_util.h"
 #include "base/string_number_conversions.h"
@@ skipping 186 matching lines @@
   // Temporary indices before kernel_ initialized in case Load fails. We 0(1)
   // swap these later.
   MetahandlesIndex metas_bucket;
   DirOpenResult result = store_->Load(&metas_bucket, &info);
   if (OPENED != result)
     return result;
 
   kernel_ = new Kernel(name, info, delegate, transaction_observer);
   kernel_->metahandles_index->swap(metas_bucket);
   InitializeIndices();
+
+  // Write back the share info to reserve some space in 'next_id'.  This will
+  // prevent local ID reuse in the case of an early crash.  See the comments in
+  // TakeSnapshotForSaveChanges() or crbug.com/142987 for more information.
+  kernel_->info_status = KERNEL_SHARE_INFO_DIRTY;
+  if (!SaveChanges()) {
+    result = FAILED_INITIAL_WRITE;

[Nicolas Zea, 2012/08/16 20:40:10]

return FAILED_INITIAL_WRITE?

[rlarocque, 2012/08/17 18:02:07]

Wow, that was a dumb mistake.  Fixed.

Unfortunately, I don't know how I could test this code path.  In fact, I'm not
even sure how this could happen.  If it does happen, though, it would be prudent
to not try using the database.

+  }
+
   return OPENED;
 }
 
 void Directory::Close() {
   store_.reset();
   if (kernel_) {
     delete kernel_;
     kernel_ = NULL;
   }
 }
@@ skipping 990 matching lines @@
   // There were no children in the linked list.
   return NULL;
 }
 
 ScopedKernelLock::ScopedKernelLock(const Directory* dir)
   :  scoped_lock_(dir->kernel_->mutex), dir_(const_cast<Directory*>(dir)) {
 }
 
 }  // namespace syncable
 }  // namespace syncer