bug#19114: 25.0.50; doc string of `eval-expression-print-format' is inappropriate

[Eli Zaretskii <eliz@gnu.org>]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Sat, 30 Apr 2016 17:13:45 +0200
> Cc: 19114@debbugs.gnu.org
> 
> Drew Adams <drew.adams@oracle.com> writes:
> 
> > The doc string says "Return a formatted string which is displayed in the
> > echo area..."  This is quite misleading.  It can easily give the
> > impression that this function displays the returned value in the echo
> > area.  THIS function does not with the formatted string, besides
> > returning it.  It displays nothing.  Please DTRT.
> 
> (defun eval-expression-print-format (value)
>   "Format VALUE as a result of evaluated expression.
> Return a formatted string which is displayed in the echo area
> in addition to the value printed by prin1 in functions which
> display the result of expression evaluation."
> 
> I don't know quite what they're trying to express here...

Much ado about nothing, if you ask me.  Replace "is displayed" with
"will be displayed", and I think the intent is more clear.

> But then again, I don't understand the meaning of the function, either:
> 
>   (if (and (integerp value)
> 	   (or (eq standard-output t)
> 	       (zerop (prefix-numeric-value current-prefix-arg))))
>       (let ((char-string
> 	     (if (and (characterp value)
> 		      (char-displayable-p value))
> 		 (prin1-char value))))
>         (if char-string
>             (format " (#o%o, #x%x, %s)" value value char-string)
>           (format " (#o%o, #x%x)" value value)))))
> 
> (eval-expression-print-format 1)
> C-x C-e
> " (#o1, #x1, ?\\C-a)" appears in *Messages*
> 
> (eval-expression-print-format 1)
> C-u C-x C-e
> => nil
> Nothing in *Messages*

Try "C-u 0", like the code says.