On Mon, Oct 10, 2016 at 8:31 AM, Sebastian Gniazdowski <
sgniazdowski@gmail.com> wrote:

> My new observations:
> – the "ndash", .i.e. this char: >>> – <<<, has a role, because
> replacing it with other char, also one like §, stops core dump
>

Your stack trace in the first message on this thread has a string as the
"exp" argument of patcompile() that makes me suspicious.  The comments say
that this argument is expected to be metafied (pattern.c 522), but as best
I can tell it's passed down from paramsubst() tokenized but not metafied.
(I don't have access to my usual debugging platform this week.)  One of the
multibyte characters in the string