def _history_matches(self, i):
        """
        True when the current entry matches the history search.
        (when we don't have history search, it's also True.)
        """
        return (self.history_search_text is None or
                self._working_lines[i].startswith(self.history_search_text))
True when the current entry matches the history search.
        (when we don't have history search, it's also True.)