bug#28108: 25.2; Infinite loop due to circular marker list?

[Eli Zaretskii]

> From: Adam Porter <adam@alphapapa.net>
> Date: Wed, 16 Aug 2017 00:01:00 -0500
> 
> I'm not much of a C programmer, nor am I experienced with gdb, but I
> attached to the Emacs process and stepped through, and every line was
> the same:
> 
> src/marker.c:605: for (tail = BUF_MARKERS (b); tail; prev =
> &tail->next, tail = *prev)

Can you show the output of

  (gdb) bt full

?