bug#31749: 26.1; Improve eldoc message commands heuristic

[Lars Ingebrigtsen <larsi@gnus.org>]

Carlos Pita <carlosjosepita@gmail.com> writes:

> The current criterion essentially removes the echo area message after
> any command not whitelisted in eldoc-message-commands.

[...]

> Now, I might be completely wrong, but why don't you just check if
> (current-message) is nil or not? This way if any command has written to
> the echo area eldoc won't override its message. You can still keep the
> whitelist in order to force override by eldoc (although I don't see much
> value in this). You have probably thought many times about this
> alternative and rejected for reasons I'm unable to see, but it's worth
> to intent ;)

(I'm going through old bug reports that unfortunately got little response at
the time.)

The way Emacs is messaging things has been changed a bit in Emacs 28,
and fewer messages are overwritten in general, but I'm not sure whether
this also covers the eldoc messages being discussed here.

Do you have a concrete case where eldoc is overwriting a message that it
shouldn't?

-- 
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   bloggy blog: http://lars.ingebrigtsen.no