drive: Add resource ID duplication check to ResourceMetadata::RefreshEntry

chrome/browser/chromeos/drive/resource_metadata.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 "chrome/browser/chromeos/drive/resource_metadata.h"
 
 #include "base/guid.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/sys_info.h"
@@ skipping 317 matching lines @@
   for (size_t i = 0; i < children.size(); ++i) {
     if (!storage_->GetEntry(children[i], &entries[i]))
       return FILE_ERROR_FAILED;
   }
   out_entries->swap(entries);
   return FILE_ERROR_OK;
 }
 
 FileError ResourceMetadata::RefreshEntry(const ResourceEntry& entry) {
   DCHECK(blocking_task_runner_->RunsTasksOnCurrentThread());
-  // TODO(hashimoto): Return an error if the operation will result in having
-  // multiple entries with the same resource ID.
 
   if (!EnoughDiskSpaceIsAvailableForDBOperation(storage_->directory_path()))
     return FILE_ERROR_NO_LOCAL_SPACE;
 
   ResourceEntry old_entry;
   if (!storage_->GetEntry(entry.local_id(), &old_entry))
     return FILE_ERROR_NOT_FOUND;
 
   if (old_entry.parent_local_id().empty() ||  // Reject root.
       old_entry.file_info().is_directory() !=  // Reject incompatible input.
       entry.file_info().is_directory())
     return FILE_ERROR_INVALID_OPERATION;
 
+  if (!entry.resource_id().empty()) {
+    // Multiple entries cannot share the same resource ID.
+    std::string local_id;
+    FileError error = GetIdByResourceId(entry.resource_id(), &local_id);
+    switch (error) {
+      case FILE_ERROR_OK:
+        if (local_id != entry.local_id())
+          return FILE_ERROR_INVALID_OPERATION;
+        break;
+
+      case FILE_ERROR_NOT_FOUND:
+        break;
+
+      default:
+        return error;
+    }
+  }
+
   // Make sure that the new parent exists and it is a directory.
   ResourceEntry new_parent;
   if (!storage_->GetEntry(entry.parent_local_id(), &new_parent))
     return FILE_ERROR_NOT_FOUND;
 
   if (!new_parent.file_info().is_directory())
     return FILE_ERROR_NOT_A_DIRECTORY;
 
   // Remove from the old parent and add it to the new parent with the new data.
   if (!PutEntryUnderDirectory(entry))
@@ skipping 122 matching lines @@
     for (size_t i = 0; i < children.size(); ++i) {
       if (!RemoveEntryRecursively(children[i]))
         return false;
     }
   }
   return storage_->RemoveEntry(id);
 }
 
 }  // namespace internal
 }  // namespace drive