* lib/resolv.rb (Resolv::DNS::Label::Str#initialize): Set encoding

ASCII-8BIT before downcase.  case insensivity of DNS labels doesn't
  apply non-ASCII characters.  [RFC 4343]



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49083 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Wed Dec 31 17:48:43 2014  Tanaka Akira  <akr@fsij.org>
+
+	* lib/resolv.rb (Resolv::DNS::Label::Str#initialize): Set encoding
+	  ASCII-8BIT before downcase.  case insensivity of DNS labels doesn't
+	  apply non-ASCII characters.  [RFC 4343]
+
 Wed Dec 31 16:48:44 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* parse.y (gettable_gen): disable warnings of possible reference

lib/resolv.rb

@@ -1170,7 +1170,9 @@ class Resolv
       class Str # :nodoc:
         def initialize(string)
           @string = string
-          @downcase = string.downcase
+          # case insensivity of DNS labels doesn't apply non-ASCII characters. [RFC 4343]
+          # This assumes @string is given in ASCII compatible encoding.
+          @downcase = string.dup.force_encoding('ASCII-8BIT').downcase
         end
         attr_reader :string, :downcase