Re: TTY frames parameters

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 24 Aug 2008 21:54:35 +0000
> Cc: emacs-devel@gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> On Sun, Aug 24, 2008 at 11:39:37PM +0300, Eli Zaretskii wrote:
> > There's a strange subtle difference between the first tty frame
> > created on a default terminal and all the other frames: the first one
> > has its `tty' association with nil cdr, while the rest have
> > "/dev/tty".  Is that a bug?
> 
> What does the frame parameter tty mean?

It's a device on which the terminal frame is displayed.  More
specifically, the calls to fwrite Emacs does to write glyphs as part
of the frame's display go to a FILE stream open on this device.

> I couldn't find it described in the Elisp manual.  Surely _that_ is
> a bug.

This parameter was introduced by the mult-tty feature.  None of that
is documented yet, except very minimally in etc/NEWS.

> On Emacs 22, there doesn't seem to be a frame-parameter called tty.  On
> Emacs 23, (running as emacs -Q on a Linux tty), I get the same symptoms
> as you do.

Thanks for testing.  I hope someone will be able to answer my
question.