    def test_fix_missing_locations(self):
        src = ast.parse('write("spam")')
        src.body.append(ast.Expr(ast.Call(ast.Name('spam', ast.Load()),
                                          [ast.Str('eggs')], [])))
        self.assertEqual(src, ast.fix_missing_locations(src))
        self.maxDiff = None
        self.assertEqual(ast.dump(src, include_attributes=True),
            "Module(body=[Expr(value=Call(func=Name(id='write', ctx=Load(), "
            "lineno=1, col_offset=0, end_lineno=1, end_col_offset=5), "
            "args=[Constant(value='spam', lineno=1, col_offset=6, end_lineno=1, "
            "end_col_offset=12)], keywords=[], lineno=1, col_offset=0, end_lineno=1, "
            "end_col_offset=13), lineno=1, col_offset=0, end_lineno=1, "
            "end_col_offset=13), Expr(value=Call(func=Name(id='spam', ctx=Load(), "
            "lineno=1, col_offset=0, end_lineno=1, end_col_offset=0), "
            "args=[Constant(value='eggs', lineno=1, col_offset=0, end_lineno=1, "
            "end_col_offset=0)], keywords=[], lineno=1, col_offset=0, end_lineno=1, "
            "end_col_offset=0), lineno=1, col_offset=0, end_lineno=1, end_col_offset=0)])"
        )
The software reads data past the end, or before the beginning, of the intended buffer.