bug#68547: [PATCH] ; Fix 'mode-line-format-right-align' with ElDoc

[Eli Zaretskii]

> From: João Távora <joaotavora@gmail.com>
> Date: Sat, 20 Jan 2024 21:12:22 +0000
> Cc: me@eshelyaron.com, 68547@debbugs.gnu.org
> 
> > Does this remove a function that existed before?  If so, please don't,
> > since that function's name didn't include "--", so it was not an
> > internal function.
> 
> The function eglot-minibuffer-message is a value for
> eldoc-message-function and it's "external" indeed.  But not by
> design rather by "status quo" -- i.e. because at the time it was
> introduced, the '-- 'convention was not always observed.
> 
> The correct way to customize ElDoc's messaging outlet is to
> set 'eldoc-message-function', the variable. That doesn't
> require referencing the should-have-been-internal symbol.

It does, if some Lisp program wants to reset the value back for some
reason.

> > (I also find the tendency of using internal functions as values of
> > variables that are clearly meant to be customized by modes to be
> > undesirable.  They are not really internal functions.)
> 
> I see nothing wrong with it.

What is wrong with it is that it's a possible value of a public
variable, so the value is basically public by definition.

> But as you noted, because of this design mistake, I've noticed
> a small number of modes do set it via 'setq'.  The correct way
> would be to create an obsolete alias.  But if you don't want
> to I won't insist, and we let this dirt persist.  There's
> certainly much worse.

Thanks, I prefer not to rename it.  Who knows what code out there
relies on it being available.