bug#38748: 28.0.50; crash on MacOS 10.15.2

[Pip Cet]

On Thu, Jan 9, 2020 at 10:31 AM Robert Pluim <rpluim@gmail.com> wrote:
>     Eli> Also, can I please see one backtrace with all the call-stack frames,
>     Eli> starting from 'main' and ending at 'handle_fatal_signal'?  The
>     Eli> original report shows only the top-most 511 frames, and the other one
>     Eli> has a lot of ?? (missing symbols) in it.
>
> 'bt full' backtrace attached.

At the risk of being wrong again, is it possible we're looking at two
different bugs? This looks like it might be a crash in mark_frame when
a "destroyed" frame's ->output_data.ns area is being accessed.

And, indeed, nsterm.m's ns_free_frame_resources contains:

  xfree (f->output_data.ns);

but not

  f->output_data.ns = NULL;
  f->output_method = output_initial;

or anything like them.