bug#30405: 26.0.91; Incorrect apostrophe translation in ImageMagick error message

[Eli Zaretskii]

> Cc: npostavs@users.sourceforge.net, 30405@debbugs.gnu.org, gazally@runbox.com
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Mon, 12 Feb 2018 11:34:13 -0800
> 
>    emacs -Q
>    M-x set-variable RET unibyte-display-via-language-environment RET t RET
>    (defun foo ()
>      (interactive)
>      (message "cannot \242")) C-j
>    M-x foo RET
> 
> because the message deliberately contains the binary byte with octal 
> value 242. It's more appropriate for this example to display "\242" in 
> the echo area than to display "¢", because the echo area is text, not 
> binary data.

I disagree, because unibyte-display-via-language-environment
explicitly requests display of raw bytes as Latin-1 characters, and it
requests that everywhere, including the echo area and whatnot.  That's
the whole raison d'être of that feature.