bug#8545: issues with recent doprnt-related changes

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: eggert@cs.ucla.edu,  8545@debbugs.gnu.org,  emacs-devel@gnu.org
> Date: Fri, 06 May 2011 14:13:06 -0300
> 
> note that "the position of the nul byte" is the same as "the length
> of the list", so it's still <= MOST_POSITIVE_FIXNUM.  It's only the
> position after the nul byte that would overflow.

But what about this code and its commentary (from
next_element_from_c_string):

  /* IT's position can be greater IT->string_nchars in case a field
     width or precision has been specified when the iterator was
     initialized.  */
  if (IT_CHARPOS (*it) >= it->end_charpos)
    {
      /* End of the game.  */
      ...

This happens when the iterator is initialized by reseat_to_string.
Admittedly, it's not very practical to have such huge strings that are
padded to an even larger width...