gdata: Fix a crash when adding a new file to a new but deleted directory.

chrome/browser/chromeos/gdata/gdata_file_system.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/gdata/gdata_file_system.h"
 
 #include <errno.h>
 #include <sys/stat.h>
 
 #include <set>
@@ skipping 3625 matching lines @@
                             &file_map,
                             &delta_feed_changestamp,
                             &num_regular_files,
                             &num_hosted_documents);
   if (error != base::PLATFORM_FILE_OK)
     return error;
 
   ApplyFeedFromFileUrlMap(
       is_delta_feed,
       is_delta_feed ? delta_feed_changestamp : root_feed_changestamp,
-      file_map);
+      &file_map);
 
   if (should_notify_initial_load)
     NotifyInitialLoadFinished();
 
   const int num_total_files = num_hosted_documents + num_regular_files;
   UMA_HISTOGRAM_COUNTS("GData.NumberOfRegularFiles", num_regular_files);
   UMA_HISTOGRAM_COUNTS("GData.NumberOfHostedDocuments",
                        num_hosted_documents);
   UMA_HISTOGRAM_COUNTS("GData.NumberOfTotalFiles", num_total_files);
   return base::PLATFORM_FILE_OK;
 }
 
 void GDataFileSystem::ApplyFeedFromFileUrlMap(
     bool is_delta_feed,
     int feed_changestamp,
-    const FileResourceIdMap& file_map) {
+    FileResourceIdMap* file_map) {
   lock_.AssertAcquired();
   // Don't send directory content change notification while performing
   // the initial content retrieval.
   const bool should_notify_directory_changed = is_delta_feed;
 
   std::set<FilePath> changed_dirs;
 
   if (!is_delta_feed) {  // Full update.
     root_->RemoveChildren();
     changed_dirs.insert(root_->GetFilePath());
   }
   root_->set_largest_changestamp(feed_changestamp);
 
   scoped_ptr<GDataRootDirectory> orphaned_entries_dir(
       new GDataRootDirectory);
   // Go through all entires generated by the feed and apply them to the local
   // snapshot of the file system.
-  for (FileResourceIdMap::const_iterator it = file_map.begin();
-       it != file_map.end(); ++it) {
+  for (FileResourceIdMap::iterator it = file_map->begin();
+       it != file_map->end();) {
+    // Ensure that the entry is deleted, unless the ownership is explicitly
+    // transferred by entry.release().
     scoped_ptr<GDataEntry> entry(it->second);
     DCHECK_EQ(it->first, entry->resource_id());
+    // Erase the entry so the deleted entry won't be referenced.
+    file_map->erase(it++);
+
     GDataEntry* old_entry = root_->GetEntryByResourceId(entry->resource_id());
     GDataDirectory* dest_dir = NULL;
     if (entry->is_deleted()) {  // Deleted file/directory.
       DVLOG(1) << "Removing file " << entry->file_name();
       if (!old_entry)
         continue;
 
       dest_dir = old_entry->parent();
       if (!dest_dir) {
         NOTREACHED();
@@ skipping 15 matching lines @@
         entry->AsGDataDirectory()->TakeOverEntries(
             old_entry->AsGDataDirectory());
       }
       // Remove the old instance of this entry.
       RemoveEntryFromDirectoryAndCollectChangedDirectories(
           dest_dir, old_entry, &changed_dirs);
       // Did we actually move the new file to another directory?
       if (dest_dir->resource_id() != entry->parent_resource_id()) {
         changed_dirs.insert(dest_dir->GetFilePath());
         dest_dir = FindDirectoryForNewEntry(entry.get(),
-                                            file_map,
+                                            *file_map,
                                             orphaned_entries_dir.get());
       }
       DCHECK(dest_dir);
       AddEntryToDirectoryAndCollectChangedDirectories(
           entry.release(),
           dest_dir,
           orphaned_entries_dir.get(),
           &changed_dirs);
     } else {  // Adding a new file.
       dest_dir = FindDirectoryForNewEntry(entry.get(),
-                                          file_map,
+                                          *file_map,
                                           orphaned_entries_dir.get());
       DCHECK(dest_dir);
       AddEntryToDirectoryAndCollectChangedDirectories(
           entry.release(),
           dest_dir,
           orphaned_entries_dir.get(),
           &changed_dirs);
     }
 
     // Record changed directory if this was a delta feed and the parent
     // directory is already properly rooted within its parent.
     if (dest_dir && (dest_dir->parent() || dest_dir == root_.get()) &&
         dest_dir != orphaned_entries_dir.get() && is_delta_feed) {
       changed_dirs.insert(dest_dir->GetFilePath());
     }
   }
+  // All entry must be erased from the map.
+  DCHECK(file_map->empty());
 
   if (should_notify_directory_changed) {
     for (std::set<FilePath>::iterator dir_iter = changed_dirs.begin();
         dir_iter != changed_dirs.end(); ++dir_iter) {
       NotifyDirectoryChanged(*dir_iter);
     }
   }
 }
 
 GDataDirectory* GDataFileSystem::FindDirectoryForNewEntry(
     GDataEntry* new_entry,
     const FileResourceIdMap& file_map,
     GDataRootDirectory* orphaned_entries_dir) {
   GDataDirectory* dir = NULL;
   // Added file.
   const std::string& parent_id = new_entry->parent_resource_id();
   if (parent_id.empty()) {
     dir = root_.get();
     DVLOG(1) << "Root parent for " << new_entry->file_name();
   } else {
     GDataEntry* entry = root_->GetEntryByResourceId(parent_id);
     dir = entry ? entry->AsGDataDirectory() : NULL;
     if (!dir) {
       // The parent directory was also added with this set of feeds.
       FileResourceIdMap::const_iterator find_iter =
           file_map.find(parent_id);
       dir = (find_iter != file_map.end() &&
              find_iter->second) ?
                 find_iter->second->AsGDataDirectory() : NULL;
-      DVLOG(1) << "Found parent for " << new_entry->file_name()
-               << " in map " << parent_id;
-      if (!dir) {
+      if (dir) {
+        DVLOG(1) << "Found parent for " << new_entry->file_name()
+                 << " in file_map " << parent_id;
+      } else {
         DVLOG(1) << "Adding orphan " << new_entry->GetFilePath().value();
         dir = orphaned_entries_dir;
       }
     }
   }
   return dir;
 }
 
 base::PlatformFileError GDataFileSystem::FeedToFileResourceMap(
     const std::vector<DocumentFeed*>& feed_list,
@@ skipping 1464 matching lines @@
   pref_registrar_->Init(profile_->GetPrefs());
   pref_registrar_->Add(prefs::kDisableGDataHostedFiles, this);
 }
 
 void SetFreeDiskSpaceGetterForTesting(FreeDiskSpaceGetterInterface* getter) {
   delete global_free_disk_getter_for_testing;  // Safe to delete NULL;
   global_free_disk_getter_for_testing = getter;
 }
 
 }  // namespace gdata