weird segfault crash

[Perry E. Metzger]

Howdy! While playing with my current project I discovered the following 
crash.

Enter this into *scratch* and eval it, then hit F19. At least on master 
under MacOS, emacs will crash with a segmentation fault.

(setq foo '(hi))

(define-key key-translation-map (kbd "<f19>")
  (lambda (n)
    (interactive "p")
    (setq foo (append foo '(there)))))

Note that if you replace the last form with (setq foo nil), the crash 
does not happen.

I'm kind of mystified by this, and not sure how to debug it.


Perry