bug#28705: 25.3; [PATCH] Change prefered coding system for Japanese language environment

[Yasuhiro KIMURA]

In current implementation, 'japanese-iso-8bit' is used as prefered
coding system when you select 'Japanese' as language environment on
Unix system. But nowaday a lot of Japanese Unix users adopt
'ja_JP.UTF-8' as locale setting. So I propose to change prefered
coding system from 'japanese-iso-8bit' to 'utf-8'. And while I'm on
it, comment is fixed to fit current implementation.

>From 2c80312989659375f82d7eefd333e5ac77663f4b Mon Sep 17 00:00:00 2001
From: Yasuhiro KIMURA <yasu@utahime.org>
Date: Wed, 4 Oct 2017 19:09:21 +0900
Subject: [PATCH] Change prefered coding system for Japanese language
 environment.

* lisp/language/japan-util.el (setup-japanese-environment-internal):
  Use utf-8 as prefered coding system instead of japanese-iso-8bit
  when system is not windows. And while I'm at it, fix comment to fit
  current implementation.
---
 lisp/language/japan-util.el | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lisp/language/japan-util.el b/lisp/language/japan-util.el
index 988b925409..fb4b408cd3 100644
--- a/lisp/language/japan-util.el
+++ b/lisp/language/japan-util.el
@@ -29,11 +29,11 @@
 
 ;;;###autoload
 (defun setup-japanese-environment-internal ()
-  ;; By default, we use 'japanese-iso-8bit for file names.  But, the
+  ;; By default, we use 'iso-2022-jp for default coding system.  But, the
   ;; following prefer-coding-system will override it.
   (if (memq system-type '(windows-nt ms-dos cygwin))
       (prefer-coding-system 'japanese-shift-jis)
-    (prefer-coding-system 'japanese-iso-8bit))
+    (prefer-coding-system 'utf-8))
   (use-cjk-char-width-table 'ja_JP))
 
 (defconst japanese-kana-table
-- 
2.14.2