Re: Menus with more items than the TTY can display

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 19 Oct 2013 20:36:07 +0200
> From: martin rudalics <rudalics@gmx.at>
> CC: emacs-devel@gnu.org
> 
> I attach two termscript files.  The first one (ts-base) is standard, the
> second (ts-rmwnil) has `resize-mini-windows' set to nil (you can see it
> in the final window).  I did F10, hit the down key 10 times and then F10
> again.  In the ts-base case I had the "--" artefact and the sticky
> highlighting as in one of the caps.
> 
> Please tell me if the differences you see have any significance.

They do, thanks.  The differences that caught my eyes are precisely in
cursor addressing, but there might be more.  I will analyze them and
see what I can find.

>  > Which reminds me: if you increase the height of that terminal window,
>  > such that the longest menu fits in its entirety without reaching the
>  > mode line, does the problem still happen?
> 
> Looks like your crystal ball knows no weekend ;-) In this case there's
> no problem.

Is it also true that the problem disappears as soon as the menu stops
overwriting the mode line?  If not, what is the minimum number of line
between the bottom of the menu and the mode line that we need to keep
to prevent the problem from happening?

> One more strange thing I noted: If I invoke
> 
> script some FILE
> 
> in the terminal just before calling emacs (to avoid calling
> `open-termscript' there) the bug does not happen either.

AFAIK, 'script' forks a shell and reads its output through a pipe (or
maybe a pty), which also slows down the terminal writes.  Or maybe
something else is at work here.

Thanks.