bug#18195: 24.3.92; window-screen-lines is not accurate

[Eli Zaretskii]

> Date: Wed, 06 Aug 2014 20:26:44 +0400
> From: Dmitry Gutov <dgutov@yandex.ru>
> CC: rudalics@gmx.at, 18195@debbugs.gnu.org
> 
> On 08/06/2014 08:23 PM, Eli Zaretskii wrote:
> 
> >> Not really. We have a pull request that changes the code to do what
> >> you're describing, but for the moment we only use one overlay at a time.
> >
> > I'm talking about a kind of menu of candidates, which definitely takes
> > more than one line.  That cannot be done with a single overlay, unless
> > you copy the buffer text into the overlay string, and completely cover
> > the buffer text itself.
> 
> Indeed, that's what we do currently.

But that will break if the buffer text has other display properties,
because Emacs doesn't support display strings on display strings.
IOW, this solution only works for relatively simple text in the
buffer.

And what do you do with line-prefix and wrap-prefix?

That's really crazy design (no offense)!