From d367b1b9f1cb7447fede62d987dbf6e8586d8f15 Mon Sep 17 00:00:00 2001
From: knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sun, 1 Jan 2012 03:26:20 +0000
Subject: [PATCH] * lib/shellwords.rb (Shellwords#shellescape): Drop the //n
 flag   that only causes warnings with no real effect.  [Bug #5637]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@34166 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog               |  5 +++++
 lib/shellwords.rb       | 12 +++++++++---
 test/test_shellwords.rb |  8 ++++++++
 3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 954672d0f8..43838901de 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Jan  1 12:23:10 2012  Akinori MUSHA  <knu@iDaemons.org>
+
+	* lib/shellwords.rb (Shellwords#shellescape): Drop the //n flag
+	  that only causes warnings with no real effect.  [Bug #5637]
+
 Sat Dec 31 06:28:37 2011  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* thread.c (rb_barrier_waiting): save the number of waiting threads
diff --git a/lib/shellwords.rb b/lib/shellwords.rb
index 5d6ba7544e..a83d1f1c86 100644
--- a/lib/shellwords.rb
+++ b/lib/shellwords.rb
@@ -75,15 +75,21 @@ module Shellwords
   #     # ...
   #   }
   #
+  # It is caller's responsibility to encode the string in the right
+  # encoding for the shell environment where this string is used.
+  # Multibyte characters are treated as multibyte characters, not
+  # bytes.
+  #
   def shellescape(str)
     # An empty argument will be skipped, so return empty quotes.
     return "''" if str.empty?
 
     str = str.dup
 
-    # Process as a single byte sequence because not all shell
-    # implementations are multibyte aware.
-    str.gsub!(/([^A-Za-z0-9_\-.,:\/@\n])/n, "\\\\\\1")
+    # Treat multibyte characters as is.  It is caller's responsibility
+    # to encode the string in the right encoding for the shell
+    # environment.
+    str.gsub!(/([^A-Za-z0-9_\-.,:\/@\n])/, "\\\\\\1")
 
     # A LF cannot be escaped with a backslash because a backslash + LF
     # combo is regarded as line continuation and simply ignored.
diff --git a/test/test_shellwords.rb b/test/test_shellwords.rb
index d48a8882c8..593f0e0aea 100644
--- a/test/test_shellwords.rb
+++ b/test/test_shellwords.rb
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 require 'test/unit'
 require 'shellwords'
 
@@ -36,4 +37,11 @@ class TestShellwords < Test::Unit::TestCase
       shellwords(bad_cmd)
     end
   end
+
+  def test_multibyte_characters
+    # This is not a spec.  It describes the current behavior which may
+    # be changed in future.  There would be no multibyte character
+    # used as shell meta-character that needs to be escaped.
+    assert_equal "\\あ\\い", "あい".shellescape
+  end
 end