bug#32064: 26; doc string of `eval-last-sexp'

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 5 Jul 2018 13:15:16 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> 
> The doc string was messed up a bit in Emacs 26, apparently for the fix
> of bug #4118.

It was also somewhat messed up in Emacs 25.

> 1. Do not truncate.
> 2. Print in additional formats.
> 
> That's fine. But the Emacs 26+ version also says that with a ZERO prefix
> arg ("such a prefix argument"), if the prefix arg is ALSO -1
> (impossible) or if "the integer" (what integer?) is less than or equal
> to the value of `eval-expression-print-maximum-character', the
> additional formats include "character".
> 
> A character is not a format, so it's unclear what printing in format
> "character" means.
> 
> But the main problem with this is that it makes us try to understand a
> prefix arg that is BOTH zero and -1, and it leaves us wondering what
> "the integer" is that is tested against
> `eval-expression-print-maximum-character' when the prefix arg is zero.
> 
> If "the integer" is just the numeric prefix arg then the <=
> `eval-expression-print-maximum-character' could be clear - but there
> should be no connection with the value being zero ("such a prefix arg").
> Just say: If zero then no truncation.  If <= `eval...' then ___
> (whatever is meant by "character format" printing).

Thanks, I fixed the doc string on the emacs-26 branch to be both clear
and correct.