bug#26396: 25.1; char-displayable-p on a latin1 tty

[Kevin Ryde]

Paul Eggert <eggert@cs.ucla.edu> writes:
>
> Rather than descend into this swamp ...

I don't want to go in a swamp :).  As much like plain tty is fine.

> I am hoping that the patch I
> installed is enough to solve Kevin's problem.

So GIO_UNIMAP internal-font-char case applies when a multibyte
terminal-coding-system ... that being presumed to be utf8 ...
and any unibyte terminal-coding-system goes down the encodeable
case.  Sounds good.

> ...
> assume that the terminal's coding system (as per Emacs) is consistent
> with the Linux console UTF-8 output mode (as per the Linux kernel),
> i.e., it's the user's responsibility to get all the settings right.

Yep, beaut.