# File lib/linecache19.rb, line 163
  def cached_script?(filename)
    # In 1.8.6, the SCRIPT_LINES__ filename key can be unqualified
    # In 1.9.1 it's the fully qualified name
    if RUBY_VERSION < "1.9"
      SCRIPT_LINES__.member?(unmap_file(filename))
    else
      SCRIPT_LINES__.member?(File.expand_path(unmap_file(filename)))
    end
  end