bug#27779: 26.0.50: read -- Re-entering top level after C stack overflow

[npostavs]

tags 27779 + confirmed
quit

Keith David Bershatsky <esq@lawlist.com> writes:

> Perhaps we can use a prior function written by @npostavs --
> (make-deep-object DEPTH) -- to create a large enough example of nested
> vectors and lists such that someone on the Emacs development team can
> duplicate the C stack overflow with `read`:
>
>     (require 'cl-lib)
>
>     (defun make-deep-object (depth)
>       (let ((obj 1))
>         (while (> (cl-decf depth) 0)
>           (setq obj (vector (list obj))))
>         obj))

Hah, yes, it seems that `read' uses up more stack than `print', e.g.,
(make-deep-object 4600) succeeds, but (read (prin1-to-string
(make-deep-object 4600))) overflows.