Re: Some vars now limited to fixnum size. (Was: Merging bignum to master)

[Eli Zaretskii]

> From: Karl Fogel <address@hidden>
> Date: Mon, 20 Aug 2018 11:28:45 -0500
> Cc: address@hidden, Pip Cet <address@hidden>, address@hidden
> 
> On 'master' as of commit ecd7a94077, if you do this:
> 
>   (setq mark-ring-max (1+ most-positive-fixnum))
> 
> then any command that calls `push-mark' will raise an error:
> 
>   Wrong type argument: fixnump, 2305843009213693952
> 
> (Lots of common commands do, obviously: `beginning-of-buffer', `yank', etc.)
> 
> The root cause is in `nthcdr', which now requires a fixnum for its first 
> argument, although this requirement is not documented:
> 
>   DEFUN ("nthcdr", Fnthcdr, Snthcdr, 2, 2, 0,
>          doc: /* Take cdr N times on LIST, return the result.  */)
>     (Lisp_Object n, Lisp_Object list)
>   {
>     CHECK_FIXNUM (n);
>     [...]
>   }
> 
> Should we document this?

Yes, I think so.