bug#18597: 25.0.50; Assertion violation in reseat_1

[martin rudalics]

> And the same in frame #8?
>
> Also, in frame 8, what do these show:
>
>    (gdb) p old_buffer->name_
>    (gdb) xstring
>    (gdb) p current_buffer->name_
>    (gdb) xstring

(gdb) frame 8
#8  0x0102231f in pos_visible_p (w=0x5af05e8, charpos=2658812, x=0x82e2cc, 
y=0x82e2c8, rtop=0x82e2c4, rbot=0x82e2c0, rowh=0x82e2bc, vpos=0x82e2b8) at 
xdisp.c:1437
1437      start_display (&it, w, top);
(gdb) p w->start
$11 = {
  i = 24813235
}
(gdb) p old_buffer->name_
Cannot access memory at address 0x4
(gdb) xstring
$12 = (struct Lisp_String *) 0x17a9eb0
0
(gdb) p current_buffer->name_
$13 = {
  i = 70507305
}
(gdb) xstring
$14 = (struct Lisp_String *) 0x433db28
"*info*"

martin