The following code causes Emacs to segfault:

  (insert (propertize "A" 'display '(disable-eval . nil)))

This is due to this code, which takes an XCAR without checking whether the spec is a cons:

  /* Support (disable-eval PROP) which is used by enriched.el.  */
  if (CONSP (spec) && EQ (XCAR (spec), Qdisable_eval))
    {
      enable_eval = false;
      spec = XCAR (XCDR (spec));
    }

The attached patch fixes this.