bug#69387: 30.0.50; A string shouldn't be both a docstring and a return value

[Eli Zaretskii]

> From: Mattias Engdegård <mattias.engdegard@gmail.com>
> Date: Mon, 4 Mar 2024 15:28:51 +0100
> Cc: Eli Zaretskii <eliz@gnu.org>,
>  69387@debbugs.gnu.org,
>  Philip Kaludercic <philipk@posteo.net>
> 
> > I agree. I'll make a patch for the warning, just so that we can see what it 
> > would look like.
> 
> Here, belatedly. It includes the lambda string change. The warning includes 
> `defun` and `defmacro` but not plain lambdas.
> 
> Removing doc strings from ambiguous lambdas didn't break anything, as 
> expected. I think the warning makes sense, because it does expose some 
> mistakes where doc strings were returned but shouldn't be, or returned 
> strings also exposed as (nonsensical) doc strings.
> 
> There are quite a few cl-defmethod forms with this syndrome but those 
> definitions never were ambiguous (the strings  are always a return value, 
> never doc string).

Do we need to say something about this change in NEWS?