    def emit(self, s, depth, reflow=True):
        # XXX reflow long lines?
        if reflow:
            lines = reflow_lines(s, depth)
        else:
            lines = [s]
        for line in lines:
            if line:
                line = (" " * TABSIZE * depth) + line
            self.file.write(line + "\n")
The software reads data past the end, or before the beginning, of the intended buffer.