# File lib/action_mailer/vendor/tmail/encode.rb, line 274 def kv_pair( k, v ) return if v.nil? v = normalize_encoding(v) if token_safe?(v) add_text k + '=' + v elsif not CONTROL_CHAR === v add_text k + '=' + quote_token(v) else # apply RFC2231 encoding kv = k + '*=' + "iso-2022-jp'ja'" + encode_value(v) add_text kv end end