# File lib/action_mailer/vendor/tmail/quoting.rb, line 100
100:         def convert_to(text, to, from)
101:           warn "Action Mailer: iconv not loaded; ignoring conversion from #{from} to #{to} (#{__FILE__}:#{__LINE__})"
102:           text
103:         end

    # File lib/action_mailer/vendor/tmail/quoting.rb, line 86
86:         def convert_to(text, to, from)
87:           return text unless to && from
88:           text ? Iconv.iconv(to, from, text).first : ""
89:         rescue Iconv::IllegalSequence, Iconv::InvalidEncoding, Errno::EINVAL
90:           # the 'from' parameter specifies a charset other than what the text
91:           # actually is...not much we can do in this case but just return the
92:           # unconverted text.
93:           #
94:           # Ditto if either parameter represents an unknown charset, like
95:           # X-UNKNOWN.
96:           text
97:         end

    # File lib/action_mailer/vendor/tmail/quoting.rb, line 50
50:       def unquote_and_convert_to(text, to_charset, from_charset = "iso-8859-1", preserve_underscores=false)
51:         return "" if text.nil?
52:         text.gsub(/(.*?)(?:(?:=\?(.*?)\?(.)\?(.*?)\?=)|$)/) do
53:           before = $1
54:           from_charset = $2
55:           quoting_method = $3
56:           text = $4
57: 
58:           before = convert_to(before, to_charset, from_charset) if before.length > 0
59:           before + case quoting_method
60:               when "q", "Q" then
61:                 unquote_quoted_printable_and_convert_to(text, to_charset, from_charset, preserve_underscores)
62:               when "b", "B" then
63:                 unquote_base64_and_convert_to(text, to_charset, from_charset)
64:               when nil then
65:                 # will be nil at the end of the string, due to the nature of
66:                 # the regex used.
67:                 ""
68:               else
69:                 raise "unknown quoting method #{quoting_method.inspect}"
70:             end
71:         end
72:       end

    # File lib/action_mailer/vendor/tmail/quoting.rb, line 80
80:       def unquote_base64_and_convert_to(text, to, from)
81:         convert_to(Base64.decode(text).first, to, from)
82:       end

    # File lib/action_mailer/vendor/tmail/quoting.rb, line 74
74:       def unquote_quoted_printable_and_convert_to(text, to, from, preserve_underscores=false)
75:         text = text.gsub(/_/, " ") unless preserve_underscores
76:         text = text.gsub(/\r\n|\r/, "\n") # normalize newlines
77:         convert_to(text.unpack("M*").first, to, from)
78:       end