From: Todd C. Miller <millert@openbsd.org>
Subject: Re: ksh: use strtonum()
To: Omar Polo <op@omarpolo.com>
Cc: tech@openbsd.org
Date: Mon, 26 Aug 2024 18:49:53 -0600

On Mon, 26 Aug 2024 23:43:54 +0200, Omar Polo wrote:

> I don't think, because it is expected to handle also !-N which is
> different from !N.
>
> It's the `start + rec + 1' part at the end of the function that handles
> the negative numbers turning them into the offset of the _last_ nth
> command, instead of the nth command.

Ah, I see.  So that:
    return start + rec + 1;

is equivalent to:
    return rec + maxhist;

OK millert@

 - todd