Add minimum width zero-padding to the index used in split output files
with -s and -o. I.e., if -s 200 is used, then the index will be
zero-padded to three digits width.
Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
                        filename = _get_filename(options.output)
                        res_list = parsing.split_res(res, options.num)
                        n = 1
+                       width = len(str(len(res_list)))
+                       s = "_%%0%dd." % width
                        for r in res_list:
                                if len(res_list) == 1:
                                        f = filename + "." + options.format
                                else:
-                                       f = filename + "_" + str(n) + "." + options.format
+                                       f = filename + s % n + options.format
                                        n = n + 1
                                def render():
                                        batch.render(writer, r, options, f)