(gdb) p *$12
$13 = {
  size = 4,
  size_byte = -1,
  intervals = 0x102a31430,
  data = 0x11433f500 " 163"
}
(gdb) up
#10438 0x00000001000393d4 in get_next_display_element (it=0x7fff5fbd5bb0)
    at xdisp.c:7324
7324      success_p = get_next_display_element (it);
(gdb) p it->current
$14 = {
  pos = {
    charpos = 4138,
    bytepos = 4138
  },
  overlay_string_index = -1,
  string_pos = {
    charpos = 6,
    bytepos = 6
  },
  dpvec_index = -1
}
(gdb) p it->sp
$15 = 2
(gdb) p it->string
$16 = Python Exception <type 'exceptions.AttributeError'> 'NoneType' object
has no attribute 'value':

(gdb) xstring
$17 = (struct Lisp_String *) 0x10da1ee10
" 163"

2017-08-02 20:32 GMT+03:00 Eli Zaretskii <eliz@gnu.org>:

> > From: Денис Редозубов <denis.redozubov@gmail.com>
> > Date: Wed, 2 Aug 2017 10:53:20 +0300
> > Cc: Eli Zaretskii <eliz@gnu.org>, 27761@debbugs.gnu.org,
> >       "Charles A. Roelli" <charles@aurox.ch>
> >
> > 7324 success_p = get_next_display_element (it);
> > (gdb) p it->current
> > $7 = {
> > pos = {
> > charpos = 4138,
> > bytepos = 4138
> > },
> > overlay_string_index = -1,
> > string_pos = {
> > charpos = 6,
> > bytepos = 6
> > },
> > dpvec_index = -1
> > }
> > (gdb) p it->sp
> > $8 = 2
> > (gdb) p it->object
> > $9 = Python Exception <type 'exceptions.AttributeError'> 'NoneType'
> object has no attribute 'value':
> >
> > (gdb) xtype
> > Lisp_String
> > (gdb) p it->position
> > $10 = {
> > charpos = 0,
> > bytepos = 0
> > }
> > (gdb) p it->string
> > $11 = Python Exception <type 'exceptions.AttributeError'> 'NoneType'
> object has no attribute 'value':
> >
> > (gdb) xstring
> > $12 = (struct Lisp_String *) 0x10da1ee10
> > " 163"
>
> Thanks.  The "charpos = 6" part puzzles me, because the string is only
> 4 characters long.  What does this produce:
>
>   (gdb) p *$12
>   (gdb) up
>   (gdb) p it->current
>   (gdb) p it->sp
>   (gdb) p it->string
>   (gdb) xstring
>