Re: Multi-tty

[Eli Zaretskii <eliz@gnu.org>]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: Gerd Möllmann <gerd.moellmann@gmail.com>,
>   emacs-devel@gnu.org
> Date: Thu, 07 Nov 2024 12:15:28 +0100
> 
> >>>>> On Thu, 07 Nov 2024 12:58:33 +0200, Eli Zaretskii <eliz@gnu.org> said:
> 
>     >> From: Gerd Möllmann <gerd.moellmann@gmail.com>
>     >> Date: Thu, 07 Nov 2024 10:53:09 +0100
>     >> 
>     >> I was playing with multi-tty today, and I encountered strange behavior.
>     >> For example, using 2 terminals that have different capabilties, say
>     >> different TERM and/or COLORTERM, does not really work.
>     >> 
>     >> (Informal example: I start an emacs server -nw in iTerm
>     >> (TERM=xterm-256color, COLORTERM=truecolor), then emacsclient --tty in a
>     >> Terminal window (TERM=xterm, COLORTERM not set) => The Emacs frame in
>     >> the Terminal window is obviously confused about the terminal's
>     >> color capabilties.)
>     >> 
>     >> Is something like that worth writing a bug report? Or maybe it's already
>     >> known, although I can't find anything in Debbugs?
> 
>     Eli> This is simply not supported, never was.  The environment variables
>     Eli> are not per-terminal, so their effect is global, and the way we
>     Eli> process them (and have no other way) is that the environment variables
>     Eli> override what terminfo tells us.
> 
> They do, but then they change the settings in the per-terminal
> tty_display_info, no? Or am I misreading init_tty? Certainly
> 
> TERM=xterm-mono emacsclient -tty
> 
> gives me a mono emacs.

I wasn't talking about TERM, I was talking about COLORTERM and its
ilk.  TERM affects the terminfo library, COLORTERM overrides that.