bug#23875: 25.0.95; Emacs crashes when closing a frame on OSX

[Alan Third <alan@idiocy.org>]

Ivan Cibrario Bertolotti <ivan.cibrario@polito.it> writes:

> unfortunately, no. I am still using Emacs with NSTRACE_ENABLED and
> NSZombiesEnabled=YES, plus some extra debugging printouts of my own,
> related to allocation and deallocation of EmacsImages. However, I
> cannot trigger the bug anymore. In my opinion, there are two possible
> reasons for this:
>
> - triggering the bug was related to “something special” I was doing
>   with Emacs at that time (somewhat unlikely), or
>
> - it is a timing-dependent bug and the debugging printouts steered
>   Emacs away from it (perhaps more likely)
>
> At this time I seldom see EmacsImage allocations/deallocations in the
> Emacs trace if at all. It seems to me that most of them are allocated
> before dumping (like fringe bitmaps in bimgs, ns_draw_fringe_bitmap,
> nsterm.m) and never deallocated.
>
> I would like to force Emacs to make heavier use of EmacsImages and
> increase the probability of running into the bug again, but I don’t
> know the code base well enough for that.
>
> If you know of any way of attaining that, please let me know and I
> will give it a try.

I'm afraid I don't know any way of doing that. I guess you could just
try loading and deleting images repeatedly:

(dotimes (i 10)
  (let ((image (find-image '((:type xpm :file "delete.xpm")))))
    (insert (propertize " " 'display `(,image (slice .0 .0 1.0 1.0)))))
  (redisplay)
  (delete-backward-char 1))

That should display a bin icon ten times quickly, but I don't know if
it'll dealloc it each time or if it gets cached in some way.

Since you're the only person to report this so far I'd be inclined to
think that perhaps some part of your configuration is causing it. Would
it be possible for you to turn off the debug output and try
systematically disabling different parts of your configuration to see if
the crashes go away? That could perhaps help us narrow down what code is
causing the crash.

-- 
Alan Third