module LineCache

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