# File lib/git-review/local.rb, line 224
    def new_commits?(upstream = false)
      # Check if an upstream remote exists and create it if necessary.
      remote_url = server.remote_url_for(*target_repo(upstream).split('/'))
      remote = remotes_for_url(remote_url).first
      unless remote
        remote = 'upstream'
        git_call "remote add #{remote} #{remote_url}"
      end
      git_call "fetch #{remote}"
      target = upstream ? "#{remote}/#{target_branch}" : target_branch
      not git_call("cherry #{target}").empty?
    end