message: use patchIndices(), because it is much faster to search only through a part branch than the complete tree
diff: @@ -168,15 +168,13 @@ QVariant DiffTreeModel::data(const QModelIndex &index, int role) const
  return QString();
  QString status;
  - QString prefix = node->path(true);
  - for (int i = 0; i < mDiff.count(); ++i) {
  - QString name = mDiff.name(i);
  - if (containsPath(name, prefix)) {
  - QChar ch = git::Diff::statusChar(mDiff.status(i));
  + QList<int> patchIndices;
  + node->patchIndices(patchIndices);
  + for (auto patchIndex: patchIndices) {
  + QChar ch = git::Diff::statusChar(mDiff.status(patchIndex));
  if (!status.contains(ch))
  status.append(ch);
  }
  - }
  return status;
  }
  