Re: Tick Reduction

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: dgutov@yandex.ru,  stefankangas@gmail.com,  emacs-devel@gnu.org
> Date: Thu, 25 Nov 2021 15:16:33 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> But...  the displayed string does end up with a text property --
> >> help-echo etc.  So text properties work fine, I think?  It's just that
> >> we don't call the `display' handler.
> >
> > I didn't say text properties on the mode line didn't work, I just
> > explained why we disregard text properties that are put on C strings.
> 
> Right, but I still don't understand how the display (resulting from
> those C strings) does have text properties, while we're not heeding the
> `display' property.  Is this a bug?

The properties are put on the mode-line elements that are Lisp
strings, in display_mode_element.  "%p" starts as a Lisp string (it
comes from bindings.el), so we do put all those text properties,
including min-width, on the Lisp string whose contents is "%p".  But
when we come to _displaying_ the result of evaluating %p, we disregard
the 'display' property on the result, because the result is a C
string.

Given this description, what exactly do you mean when you say you
don't understand "how the display (resulting from those C strings)
does have text properties"?  How do you see that "the display does
have text properties"?