bug#62237: 28.1 or higher: 24-bit true color breaks colours in Emacsen built without X under GNU Screen

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: sdt@sebyte.me,  62237@debbugs.gnu.org
> Date: Sat, 18 Mar 2023 10:05:49 +0100
> 
> >>>>> On Fri, 17 Mar 2023 20:55:23 +0200, Eli Zaretskii <eliz@gnu.org> said:
>     >> machines you are able to do a rlogin and still keep the  correct  term‐
>     --> cap/terminfo  entry.  The terminal name is put in the $TERM variable 
> of
>     >> all new windows.  Screen also sets the $TERMCAP variable reflecting the
>     >> capabilities of the virtual terminal emulated. Notice that, however, on
>     >> machines using the terminfo database this variable has no effect.  Fur‐
>     >> thermore, the variable $WINDOW is set to the window number of each win‐
>     >> dow.
> 
>     Eli> This seems to tell how 'screen' figures out the terminal name, not 
> how
>     Eli> it sets TERM.  I asked who and why sets TERM to screen.SOMETHING.
> 
> screen does: "The terminal name is put in the $TERM variable of all new 
> windows."

So how did Emacs ever succeed to work inside screen, then?  AFAIK, we
never supported this form of TERM's value.  Is this something
relatively new?