# File lib/mail/version_specific/ruby_1_9.rb, line 103
    def Ruby19.fix_encoding(encoding)
      case encoding
        # ISO-8859-15, ISO-2022-JP and alike
        when /iso-?(\d{4})-?(\w{1,2})/i then return "ISO-#{$1}-#{$2}"
        # "ISO-2022-JP-KDDI"  and alike
        when /iso-?(\d{4})-?(\w{1,2})-?(\w*)/i then return "ISO-#{$1}-#{$2}-#{$3}"
        # UTF-8, UTF-32BE and alike
        when /utf-?(\d{1,2})?(\w{1,2})/i then return "UTF-#{$1}#{$2}".gsub(/\A(UTF-(?:16|32))\z/, '\\1BE')
        # Windows-1252 and alike
        when /Windows-?(.*)/i then return "Windows-#{$1}"
        when /^8bit$/ then return "ASCII-8BIT"
        #more aliases to be added if needed
        else return encoding
      end
    end