bug#26650: 26.0.50; Protect *Backtrace* from accidental killing

[Tino Calancha <tino.calancha@gmail.com>]

On Tue, 25 Apr 2017, npostavs@users.sourceforge.net wrote:

> tags 26650 patch
> quit
>
> Tino Calancha <tino.calancha@gmail.com> writes:
>
>>>
>>> That's because you're still in the recursive edit, it's like evaluating
>>> '(error "hi")' before hitting 'q' in the *Backtrace* buffer.  You can
>>> use C-M-c (exit-recursive-edit) to get back to normal.  I think it would
>>> make sense to do that automatically if you kill the *Backtrace* buffer.
>> Yes, it would be useful.  I don't know how, though.
>> Sometimes i kill *Bactrace* from *Ibuffer*/*Buffer List* with the
>> recursive edit still ongoing.  It's a classical mistake.
>
> Actually, the obvious way of adding `top-level' (that's what 'q' does)
> to `kill-buffer-hook' does protect *Backtrace* from killing.
Good!  It solves the issue.