support MS950 encoding

close #1406

Author: tonytonyjan

lib/mail/utilities.rb

@@ -526,6 +526,10 @@ def Utilities.pick_encoding(charset)
       when 'latin2'
         Encoding::ISO_8859_2
 
+      # Microsoft-specific alias for CP950 (Traditional Chinese)
+      when 'ms950'
+        Encoding::CP950
+
       else
         charset
       end

spec/mail/encoding_spec.rb

@@ -206,6 +206,7 @@
       "latin2" => Encoding::ISO_8859_2,
       "ISO_8859-1" => Encoding::ISO_8859_1,
       "cp-850" => Encoding::CP850,
+      "MS950" => Encoding::CP950,
       "" => Encoding::BINARY
     }.each do |from, to|
       it "should support #{from}" do