bug#30519: 26.0.91; Emacs hangs with flyspell overlay

[Romanos Skiadas <rom.skiad@gmail.com>]

On 19/02/18 23:47, Dmitry Gutov wrote:
> On 2/19/18 6:32 PM, Eli Zaretskii wrote:
>
>>> Emacs hangs with repeating error "Marker does not point anywhere". You
>>> can clear the hang by moving the mouse pointer.
>>
>> Not reproducible here.  Could this be X-specific (I tried on Windows)?
>
> I can reproduce this in emacs-26 (Ubuntu 17.10 with GTK3 here).
>
>
>
I can see it as well on emacs 27, Ubuntu 17.10 w/ GTK3. This is where it 
comes from:

Thread 1 "emacs" hit Breakpoint 1, marker_position (marker=0x3463451) at 
marker.c:641
641        error ("Marker does not point anywhere");
(gdb) l
636    {
637      register struct Lisp_Marker *m = XMARKER (marker);
638      register struct buffer *buf = m->buffer;
639
640      if (!buf)
641        error ("Marker does not point anywhere");
642

buf is null.

It's a bit too late here to dig into this more.