Subject: bug#27834: 25.2.50; Deleting a frame on macOS while in fullscreen always crashes

From: Eli Zaretskii <[email-masked]>
Date: Wed, 26 Jul 2017 17:31:28 +0300

> From: John Wiegley <[email-masked]>
> Date: Tue, 25 Jul 2017 20:17:00 -0400
> 
>  1. Enter fullscreen.  I use this function to do so:
> 
>     (defun emacs-max ()
>       (interactive)
>       (set-frame-parameter (selected-frame) 'fullscreen 'fullboth)
>       (set-frame-parameter (selected-frame) 'vertical-scroll-bars nil)
>       (set-frame-parameter (selected-frame) 'horizontal-scroll-bars nil))
> 
>  2. Create another frame with C-x 5 2.
> 
>  3. Delete that frame immediately with C-x 5 0.
> 
>  4. Emacs crashes. Crash report attached.

It didn't crash for me (not on macOS).  Looks macOS-specific.