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

[Ivan Cibrario Bertolotti]

Hi Alan,

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.

Thanks,
Ivan


> On 11 Sep 2016, at 12:15, Alan Third <alan@idiocy.org> wrote:
> 
> Ivan Cibrario Bertolotti <ivan.cibrario@polito.it> writes:
> 
>>> I'm not sure how to go about debugging this stuff, but NSZombiesEnabled
>>> seems to be the way:
>>> 
>>> $ NSZombiesEnabled=YES /path/to/emacs.app/Contents/MacOS/Emacs
>>> 
>>> this should print out a message when an object is deallocated too many
>>> times, instead of just crashing.
>> 
>>> -- 
>>> Alan Third
>> 
>> I understand, it looks nasty indeed and it happens on average only
>> once a day. Thank you for the hint. I will keep using Emacs with
>> NSTRACE_ENABLED and NSZombiesEnabled=YES. Will get back as soon as I
>> have more substantial information.
> 
> Hi Ivan, did you ever get anywhere with this?
> -- 
> Alan Third