bug#27517: 26.0.50; 25.2.2; Cannot add "help-echo" property to buffer regions in *lisp-mode

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> This happens because lisp-mode.el wants itself to manage the help-echo
> property:

[...]

>           (font-lock-extra-managed-props help-echo)
>
> When a property appears in font-lock-extra-managed-props, font-lock
> removes that property when it's about to re-fontify some region, see
> font-lock-default-unfontify-region.

This is presumably so that font-locking can add help-echo warnings like

+       (lisp--match-hidden-arg
+        (0 '(face font-lock-warning-face
+             help-echo "Hidden behind deeper element; move to another line?")))

which seems useful.

But it'd also be nice to allow other packages to also add help-echo on
bits and bobs.  Is there no way to achieve that?

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