sup

lib/sup/message.rb (26778B) - raw

 # encoding: UTF-8
 
 require 'time'
 require 'string-scrub' if /^2\.0\./ =~ RUBY_VERSION
 
 module Redwood
 
 ## a Message is what's threaded.
 ##
 ## it is also where the parsing for quotes and signatures is done, but
 ## that should be moved out to a separate class at some point (because
 ## i would like, for example, to be able to add in a ruby-talk
 ## specific module that would detect and link to /ruby-talk:\d+/
 ## sequences in the text of an email. (how sweet would that be?)
 
 class Message
   SNIPPET_LEN = 80
   RE_PATTERN = /^((re|re[\[\(]\d[\]\)]):\s*)+/i
 
   ## some utility methods
   class << self
     def normalize_subj s; s.gsub(RE_PATTERN, ""); end
     def subj_is_reply? s; s =~ RE_PATTERN; end
     def reify_subj s; subj_is_reply?(s) ? s : "Re: " + s; end
   end
 
   QUOTE_PATTERN = /^\s{0,4}[>|\}]/
   BLOCK_QUOTE_PATTERN = /^-----\s*Original Message\s*----+$/
   SIG_PATTERN = /(^(- )*-- ?$)|(^\s*----------+\s*$)|(^\s*_________+\s*$)|(^\s*--~--~-)|(^\s*--\+\+\*\*==)/
 
   GPG_SIGNED_START = "-----BEGIN PGP SIGNED MESSAGE-----"
   GPG_SIGNED_END = "-----END PGP SIGNED MESSAGE-----"
   GPG_START = "-----BEGIN PGP MESSAGE-----"
   GPG_END = "-----END PGP MESSAGE-----"
   GPG_SIG_START = "-----BEGIN PGP SIGNATURE-----"
   GPG_SIG_END = "-----END PGP SIGNATURE-----"
 
   MAX_SIG_DISTANCE = 15 # lines from the end
   DEFAULT_SUBJECT = ""
   DEFAULT_SENDER = "(missing sender)"
   MAX_HEADER_VALUE_SIZE = 4096
 
   attr_reader :id, :date, :from, :subj, :refs, :replytos, :to,
               :cc, :bcc, :labels, :attachments, :list_address, :recipient_email, :replyto,
               :list_subscribe, :list_unsubscribe
 
   bool_reader :dirty, :source_marked_read, :snippet_contains_encrypted_content
 
   attr_accessor :locations
 
   ## if you specify a :header, will use values from that. otherwise,
   ## will try and load the header from the source.
   def initialize opts
     @locations = opts[:locations] or raise ArgumentError, "locations can't be nil"
     @snippet = opts[:snippet]
     @snippet_contains_encrypted_content = false
     @have_snippet = !(opts[:snippet].nil? || opts[:snippet].empty?)
     @labels = Set.new(opts[:labels] || [])
     @dirty = false
     @encrypted = false
     @chunks = nil
     @attachments = []
 
     ## we need to initialize this. see comments in parse_header as to
     ## why.
     @refs = []
 
     #parse_header(opts[:header] || @source.load_header(@source_info))
   end
 
   def decode_header_field v
     return unless v
     return v unless v.is_a? String
     return unless v.size < MAX_HEADER_VALUE_SIZE # avoid regex blowup on spam
     ## Header values should be either 7-bit with RFC2047-encoded words
     ## or UTF-8 as per RFC6532. Replace any invalid high bytes with U+FFFD.
     Rfc2047.decode_to $encoding, v.dup.force_encoding(Encoding::UTF_8).scrub
   end
 
   def parse_header encoded_header
     header = SavingHash.new { |k| decode_header_field encoded_header[k] }
 
     @id = ''
     if header["message-id"]
       mid = header["message-id"] =~ /<(.+?)>/ ? $1 : header["message-id"]
       @id = sanitize_message_id mid
     end
     if (not @id.include? '@') || @id.length < 6
       @id = "sup-faked-" + Digest::MD5.hexdigest(raw_header)
       #from = header["from"]
       #debug "faking non-existent message-id for message from #{from}: #{id}"
     end
 
     @from = Person.from_address(if header["from"]
       header["from"]
     else
       name = "Sup Auto-generated Fake Sender <sup@fake.sender.example.com>"
       #debug "faking non-existent sender for message #@id: #{name}"
       name
     end)
 
     @date = case(date = header["date"])
     when Time
       date
     when String
       Time.rfc2822 date rescue nil
     end
     @date = location.fallback_date if @date.nil?
     @date = Time.utc 1970, 1, 1 if @date.nil?
 
     subj = header["subject"]
     subj = subj ? subj.fix_encoding! : nil
     @subj = subj ? subj.gsub(/\s+/, " ").gsub(/\s+$/, "") : DEFAULT_SUBJECT
     @to = Person.from_address_list header["to"]
     @cc = Person.from_address_list header["cc"]
     @bcc = Person.from_address_list header["bcc"]
 
     ## before loading our full header from the source, we can actually
     ## have some extra refs set by the UI. (this happens when the user
     ## joins threads manually). so we will merge the current refs values
     ## in here.
     refs = (header["references"] || "").scan(/<(.+?)>/).map { |x| sanitize_message_id x.first }
     @refs = (@refs + refs).uniq
     @replytos = (header["in-reply-to"] || "").scan(/<(.+?)>/).map { |x| sanitize_message_id x.first }
 
     @replyto = Person.from_address header["reply-to"]
     @list_address = if header["list-post"]
       address = if header["list-post"] =~ /mailto:(.*?)[>\s$]/
         $1
       elsif header["list-post"] =~ /@/
         header["list-post"] # just try the whole fucking thing
       end
       address && Person.from_address(address)
     elsif header["mailing-list"]
       address = if header["mailing-list"] =~ /list (.*?);/
         $1
       end
       address && Person.from_address(address)
     elsif header["x-mailing-list"]
       Person.from_address header["x-mailing-list"]
     end
 
     @recipient_email = header["envelope-to"] || header["x-original-to"] || header["delivered-to"]
     @source_marked_read = header["status"] == "RO"
     @list_subscribe = header["list-subscribe"]
     @list_unsubscribe = header["list-unsubscribe"]
   end
 
   ## Expected index entry format:
   ## :message_id, :subject => String
   ## :date => Time
   ## :refs, :replytos => Array of String
   ## :from => Person
   ## :to, :cc, :bcc => Array of Person
   def load_from_index! entry
     @id = entry[:message_id]
     @from = entry[:from]
     @date = entry[:date]
     @subj = entry[:subject]
     @to = entry[:to]
     @cc = entry[:cc]
     @bcc = entry[:bcc]
     @refs = (@refs + entry[:refs]).uniq
     @replytos = entry[:replytos]
 
     @replyto = nil
     @list_address = nil
     @recipient_email = nil
     @source_marked_read = false
     @list_subscribe = nil
     @list_unsubscribe = nil
   end
 
   def add_ref ref
     @refs << ref
     @dirty = true
   end
 
   def remove_ref ref
     @dirty = true if @refs.delete ref
   end
 
   attr_reader :snippet
   def is_list_message?; !@list_address.nil?; end
   def is_draft?; @labels.member? :draft; end
   def draft_filename
     raise "not a draft" unless is_draft?
     source.fn_for_offset source_info
   end
 
   ## sanitize message ids by removing spaces and non-ascii characters.
   ## also, truncate to 255 characters. all these steps are necessary
   ## to make the index happy. of course, we probably fuck up a couple
   ## valid message ids as well. as long as we're consistent, this
   ## should be fine, though.
   ##
   ## also, mostly the message ids that are changed by this belong to
   ## spam email.
   ##
   ## an alternative would be to SHA1 or MD5 all message ids on a regular basis.
   ## don't tempt me.
   def sanitize_message_id mid; mid.gsub(/(\s|[^\000-\177])+/, "")[0..254] end
 
   def clear_dirty
     @dirty = false
   end
 
   def has_label? t; @labels.member? t; end
   def add_label l
     l = l.to_sym
     return if @labels.member? l
     @labels << l
     @dirty = true
   end
   def remove_label l
     l = l.to_sym
     return unless @labels.member? l
     @labels.delete l
     @dirty = true
   end
 
   def recipients
     @to + @cc + @bcc
   end
 
   def labels= l
     raise ArgumentError, "not a set" unless l.is_a?(Set)
     raise ArgumentError, "not a set of labels" unless l.all? { |ll| ll.is_a?(Symbol) }
     return if @labels == l
     @labels = l
     @dirty = true
   end
 
   def chunks
     load_from_source!
     @chunks
   end
 
   def location
     @locations.find { |x| x.valid? } || raise(OutOfSyncSourceError.new)
   end
 
   def source
     location.source
   end
 
   def source_info
     location.info
   end
 
   ## this is called when the message body needs to actually be loaded.
   def load_from_source!
     @chunks ||=
       begin
         ## we need to re-read the header because it contains information
         ## that we don't store in the index. actually i think it's just
         ## the mailing list address (if any), so this is kinda overkill.
         ## i could just store that in the index, but i think there might
         ## be other things like that in the future, and i'd rather not
         ## bloat the index.
         ## actually, it's also the differentiation between to/cc/bcc,
         ## so i will keep this.
         rmsg = location.parsed_message
         parse_header rmsg.header
         message_to_chunks rmsg
       rescue SourceError, SocketError, RMail::EncodingUnsupportedError => e
         warn_with_location "problem reading message #{id}"
         debug "could not load message, exception: #{e.inspect}"
 
         [Chunk::Text.new(error_message.split("\n"))]
 
       rescue Exception => e
 
         warn_with_location "problem reading message #{id}"
         debug "could not load message: #{location.inspect}, exception: #{e.inspect}"
 
         raise e
 
       end
   end
 
   def reload_from_source!
     @chunks = nil
     load_from_source!
   end
 
 
   def error_message
     <<EOS
 #@snippet...
 
 ***********************************************************************
  An error occurred while loading this message.
 ***********************************************************************
 EOS
   end
 
   def raw_header
     location.raw_header
   end
 
   def raw_message
     location.raw_message
   end
 
   def each_raw_message_line &b
     location.each_raw_message_line(&b)
   end
 
   def sync_back
     @locations.map { |l| l.sync_back @labels, self }.any? do
       UpdateManager.relay self, :updated, self
     end
   end
 
   def merge_labels_from_locations merge_labels
     ## Get all labels from all locations
     location_labels = Set.new([])
 
     @locations.each do |l|
       if l.valid?
         location_labels = location_labels.union(l.labels?)
       end
     end
 
     ## Add to the message labels the intersection between all location
     ## labels and those we want to merge
     location_labels = location_labels.intersection(merge_labels.to_set)
 
     if not location_labels.empty?
       @labels = @labels.union(location_labels)
       @dirty = true
     end
   end
 
   def indexable_body
     indexable_chunks.map { |c| c.lines }.flatten.compact.join " "
   end
 
   def indexable_chunks
     chunks.select { |c| c.indexable? } || []
   end
 
   def indexable_subject
     Message.normalize_subj(subj)
   end
 
   def quotable_body_lines
     chunks.find_all { |c| c.quotable? }.map { |c| c.lines }.flatten
   end
 
   def quotable_header_lines
     ["From: #{@from.full_address}"] +
       (@to.empty? ? [] : ["To: " + @to.map { |p| p.full_address }.join(", ")]) +
       (@cc.empty? ? [] : ["Cc: " + @cc.map { |p| p.full_address }.join(", ")]) +
       (@bcc.empty? ? [] : ["Bcc: " + @bcc.map { |p| p.full_address }.join(", ")]) +
       ["Date: #{@date.rfc822}",
        "Subject: #{@subj}"]
   end
 
   def self.build_from_source source, source_info
     m = Message.new :locations => [Location.new(source, source_info)]
     m.load_from_source!
     m
   end
 
 private
 
   ## here's where we handle decoding mime attachments. unfortunately
   ## but unsurprisingly, the world of mime attachments is a bit of a
   ## mess. as an empiricist, i'm basing the following behavior on
   ## observed mail rather than on interpretations of rfcs, so probably
   ## this will have to be tweaked.
   ##
   ## the general behavior i want is: ignore content-disposition, at
   ## least in so far as it suggests something being inline vs being an
   ## attachment. (because really, that should be the recipient's
   ## decision to make.) if a mime part is text/plain, OR if the user
   ## decoding hook converts it, then decode it and display it
   ## inline. for these decoded attachments, if it has associated
   ## filename, then make it collapsable and individually saveable;
   ## otherwise, treat it as regular body text.
   ##
   ## everything else is just an attachment and is not displayed
   ## inline.
   ##
   ## so, in contrast to mutt, the user is not exposed to the workings
   ## of the gruesome slaughterhouse and sausage factory that is a
   ## mime-encoded message, but need only see the delicious end
   ## product.
 
   def multipart_signed_to_chunks m
     if m.body.size != 2
       warn_with_location "multipart/signed with #{m.body.size} parts (expecting 2)"
       return
     end
 
     payload, signature = m.body
     if signature.multipart?
       warn_with_location "multipart/signed with payload multipart #{payload.multipart?} and signature multipart #{signature.multipart?}"
       return
     end
 
     ## this probably will never happen
     if payload.header.content_type && payload.header.content_type.downcase == "application/pgp-signature"
       warn_with_location "multipart/signed with payload content type #{payload.header.content_type}"
       return
     end
 
     if signature.header.content_type && signature.header.content_type.downcase != "application/pgp-signature"
       ## unknown signature type; just ignore.
       #warn "multipart/signed with signature content type #{signature.header.content_type}"
       return
     end
 
     [CryptoManager.verify(payload, signature), message_to_chunks(payload)].flatten.compact
   end
 
   def multipart_encrypted_to_chunks m
     if m.body.size != 2
       warn_with_location "multipart/encrypted with #{m.body.size} parts (expecting 2)"
       return
     end
 
     control, payload = m.body
     if control.multipart?
       warn_with_location "multipart/encrypted with control multipart #{control.multipart?} and payload multipart #{payload.multipart?}"
       return
     end
 
     if payload.header.content_type && payload.header.content_type.downcase != "application/octet-stream"
       warn_with_location "multipart/encrypted with payload content type #{payload.header.content_type}"
       return
     end
 
     if control.header.content_type && control.header.content_type.downcase != "application/pgp-encrypted"
       warn_with_location "multipart/encrypted with control content type #{signature.header.content_type}"
       return
     end
 
     notice, sig, decryptedm = CryptoManager.decrypt payload
     if decryptedm # managed to decrypt
       children = message_to_chunks(decryptedm, true)
       [notice, sig].compact + children
     else
       [notice]
     end
   end
 
   def has_embedded_message? m
     return false unless m.header.content_type
     %w(message/rfc822 message/global).include? m.header.content_type.downcase
   end
 
   ## takes a RMail::Message, breaks it into Chunk:: classes.
   def message_to_chunks m, encrypted=false, sibling_types=[]
     if m.multipart?
       chunks =
         case m.header.content_type.downcase
         when "multipart/signed"
           multipart_signed_to_chunks m
         when "multipart/encrypted"
           multipart_encrypted_to_chunks m
         end
 
       unless chunks
         sibling_types = m.body.map { |p| p.header.content_type }
         chunks = m.body.map { |p| message_to_chunks p, encrypted, sibling_types }.flatten.compact
       end
 
       chunks
     elsif has_embedded_message? m
       encoding = m.header["Content-Transfer-Encoding"]
       if m.body
         body =
         case encoding
         when "base64"
           m.body.unpack("m")[0]
         when "quoted-printable"
           m.body.unpack("M")[0]
         when "7bit", "8bit", nil
           m.body
         else
           raise RMail::EncodingUnsupportedError, encoding.inspect
         end
         body = body.normalize_whitespace
         payload = RMail::Parser.read(body)
         from = payload.header.from.first ? payload.header.from.first.format : ""
         to = payload.header.to.map { |p| p.format }.join(", ")
         cc = payload.header.cc.map { |p| p.format }.join(", ")
         subj = decode_header_field(payload.header.subject) || DEFAULT_SUBJECT
         subj = Message.normalize_subj(subj.gsub(/\s+/, " ").gsub(/\s+$/, ""))
         msgdate = payload.header.date
         from_person = from ? Person.from_address(decode_header_field(from)) : nil
         to_people = to ? Person.from_address_list(decode_header_field(to)) : nil
         cc_people = cc ? Person.from_address_list(decode_header_field(cc)) : nil
         [Chunk::EnclosedMessage.new(from_person, to_people, cc_people, msgdate, subj)] + message_to_chunks(payload, encrypted)
       else
         debug "no body for message/rfc822 enclosure; skipping"
         []
       end
     elsif m.header.content_type && m.header.content_type.downcase == "application/pgp" && m.body
       ## apparently some versions of Thunderbird generate encryped email that
       ## does not follow RFC3156, e.g. messages with X-Enigmail-Version: 0.95.0
       ## they have no MIME multipart and just set the body content type to
       ## application/pgp. this handles that.
       ##
       ## TODO 1: unduplicate code between here and
       ##         multipart_encrypted_to_chunks
       ## TODO 2: this only tries to decrypt. it cannot handle inline PGP
       notice, sig, decryptedm = CryptoManager.decrypt m.body
       if decryptedm # managed to decrypt
         children = message_to_chunks decryptedm, true
         [notice, sig].compact + children
       else
         ## try inline pgp signed
       	chunks = inline_gpg_to_chunks m.body, $encoding, (m.charset || $encoding)
         if chunks
           chunks
         else
           [notice]
         end
       end
     else
       filename =
         ## first, paw through the headers looking for a filename.
         ## RFC 2183 (Content-Disposition) specifies that disposition-parms are
         ## separated by ";". So, we match everything up to " and ; (if present).
         if m.header["Content-Disposition"] && m.header["Content-Disposition"] =~ /filename="?(.*?[^\\])("|;|\z)/m
           $1
         elsif m.header["Content-Type"] && m.header["Content-Type"] =~ /name="?(.*?[^\\])("|;|\z)/im
           $1
 
         ## haven't found one, but it's a non-text message. fake
         ## it.
         ##
         ## TODO: make this less lame.
         elsif m.header["Content-Type"] && m.header["Content-Type"] !~ /^text\/plain/i
           extension =
             case m.header["Content-Type"]
             when /text\/html/ then "html"
             when /image\/(.*)/ then $1
             end
 
           ["sup-attachment-#{Time.now.to_i}-#{rand 10000}", extension].join(".")
         end
 
       ## if there's a filename, we'll treat it as an attachment.
       if filename
         ## filename could be 2047 encoded
         filename = Rfc2047.decode_to $encoding, filename
         # add this to the attachments list if its not a generated html
         # attachment (should we allow images with generated names?).
         # Lowercase the filename because searches are easier that way
         @attachments.push filename.downcase unless filename =~ /^sup-attachment-/
         add_label :attachment unless filename =~ /^sup-attachment-/
         content_type = (m.header.content_type || "application/unknown").downcase # sometimes RubyMail gives us nil
         [Chunk::Attachment.new(content_type, filename, m, sibling_types)]
 
       ## otherwise, it's body text
       else
         ## Decode the body, charset conversion will follow either in
         ## inline_gpg_to_chunks (for inline GPG signed messages) or
         ## a few lines below (messages without inline GPG)
         body = m.body ? m.decode : ""
 
         ## Check for inline-PGP
         chunks = inline_gpg_to_chunks body, $encoding, (m.charset || $encoding)
         return chunks if chunks
 
         if m.body
           ## if there's no charset, use the current encoding as the charset.
           ## this ensures that the body is normalized to avoid non-displayable
           ## characters
           body = m.decode.transcode($encoding, m.charset)
         else
           body = ""
         end
 
         text_to_chunks(body.normalize_whitespace.split("\n"), encrypted)
       end
     end
   end
 
   ## looks for gpg signed (but not encrypted) inline  messages inside the
   ## message body (there is no extra header for inline GPG) or for encrypted
   ## (and possible signed) inline GPG messages
   def inline_gpg_to_chunks body, encoding_to, encoding_from
     lines = body.split("\n")
 
     # First case: Message is enclosed between
     #
     # -----BEGIN PGP SIGNED MESSAGE-----
     # and
     # -----END PGP SIGNED MESSAGE-----
     #
     # In some cases, END PGP SIGNED MESSAGE doesn't appear
     # (and may leave strange -----BEGIN PGP SIGNATURE----- ?)
     gpg = lines.between(GPG_SIGNED_START, GPG_SIGNED_END)
     # between does not check if GPG_END actually exists
     # Reference: http://permalink.gmane.org/gmane.mail.sup.devel/641
     if !gpg.empty?
       msg = RMail::Message.new
       msg.body = gpg.join("\n")
 
       body = body.transcode(encoding_to, encoding_from)
       lines = body.split("\n")
       sig = lines.between(GPG_SIGNED_START, GPG_SIG_START)
       startidx = lines.index(GPG_SIGNED_START)
       endidx = lines.index(GPG_SIG_END)
       before = startidx != 0 ? lines[0 .. startidx-1] : []
       after = endidx ? lines[endidx+1 .. lines.size] : []
 
       # sig contains BEGIN PGP SIGNED MESSAGE and END PGP SIGNATURE, so
       # we ditch them. sig may also contain the hash used by PGP (with a
       # newline), so we also skip them
       sig_start = sig[1].match(/^Hash:/) ? 3 : 1
       sig_end = sig.size-2
       payload = RMail::Message.new
       payload.body = sig[sig_start, sig_end].join("\n")
       return [text_to_chunks(before, false),
               CryptoManager.verify(nil, msg, false),
               message_to_chunks(payload),
               text_to_chunks(after, false)].flatten.compact
     end
 
     # Second case: Message is encrypted
 
     gpg = lines.between(GPG_START, GPG_END)
     # between does not check if GPG_END actually exists
     if !gpg.empty? && !lines.index(GPG_END).nil?
       msg = RMail::Message.new
       msg.body = gpg.join("\n")
 
       startidx = lines.index(GPG_START)
       before = startidx != 0 ? lines[0 .. startidx-1] : []
       after = lines[lines.index(GPG_END)+1 .. lines.size]
 
       notice, sig, decryptedm = CryptoManager.decrypt msg, true
       chunks = if decryptedm # managed to decrypt
         children = message_to_chunks(decryptedm, true)
         [notice, sig].compact + children
       else
         [notice]
       end
       return [text_to_chunks(before, false),
               chunks,
               text_to_chunks(after, false)].flatten.compact
     end
   end
 
   ## parse the lines of text into chunk objects.  the heuristics here
   ## need tweaking in some nice manner. TODO: move these heuristics
   ## into the classes themselves.
   def text_to_chunks lines, encrypted
     state = :text # one of :text, :quote, or :sig
     chunks = []
     chunk_lines = []
     nextline_index = -1
 
     lines.each_with_index do |line, i|
       if i >= nextline_index
         # look for next nonblank line only when needed to avoid O(n²)
         # behavior on sequences of blank lines
         if nextline_index = lines[(i+1)..-1].index { |l| l !~ /^\s*$/ } # skip blank lines
           nextline_index += i + 1
           nextline = lines[nextline_index]
         else
           nextline_index = lines.length
           nextline = nil
         end
       end
 
       case state
       when :text
         newstate = nil
 
         ## the following /:$/ followed by /\w/ is an attempt to detect the
         ## start of a quote. this is split into two regexen because the
         ## original regex /\w.*:$/ had very poor behavior on long lines
         ## like ":a:a:a:a:a" that occurred in certain emails.
         if line =~ QUOTE_PATTERN || (line =~ /:$/ && line =~ /\w/ && nextline =~ QUOTE_PATTERN)
           newstate = :quote
         elsif line =~ SIG_PATTERN && (lines.length - i) < MAX_SIG_DISTANCE && !lines[(i+1)..-1].index { |l| l =~ /^-- $/ }
           newstate = :sig
         elsif line =~ BLOCK_QUOTE_PATTERN && nextline !~ QUOTE_PATTERN
           newstate = :block_quote
         end
 
         if newstate
           chunks << Chunk::Text.new(chunk_lines) unless chunk_lines.empty?
           chunk_lines = [line]
           state = newstate
         else
           chunk_lines << line
         end
 
       when :quote
         newstate = nil
 
         if line =~ QUOTE_PATTERN || (line =~ /^\s*$/ && nextline =~ QUOTE_PATTERN)
           chunk_lines << line
         elsif line =~ SIG_PATTERN && (lines.length - i) < MAX_SIG_DISTANCE
           newstate = :sig
         else
           newstate = :text
         end
 
         if newstate
           if chunk_lines.empty?
             # nothing
           else
             chunks << Chunk::Quote.new(chunk_lines)
           end
           chunk_lines = [line]
           state = newstate
         end
 
       when :block_quote, :sig
         chunk_lines << line
       end
 
       if !@have_snippet && state == :text && (@snippet.nil? || @snippet.length < SNIPPET_LEN) && line !~ /[=\*#_-]{3,}/ && line !~ /^\s*$/
         @snippet ||= ""
         @snippet += " " unless @snippet.empty?
         @snippet += line.gsub(/^\s+/, "").gsub(/[\r\n]/, "").gsub(/\s+/, " ")
         oldlen = @snippet.length
         @snippet = @snippet[0 ... SNIPPET_LEN].chomp
         @snippet += "..." if @snippet.length < oldlen
         @dirty = true unless encrypted && $config[:discard_snippets_from_encrypted_messages]
         @snippet_contains_encrypted_content = true if encrypted
       end
     end
 
     ## final object
     case state
     when :quote, :block_quote
       chunks << Chunk::Quote.new(chunk_lines) unless chunk_lines.empty?
     when :text
       chunks << Chunk::Text.new(chunk_lines) unless chunk_lines.empty?
     when :sig
       chunks << Chunk::Signature.new(chunk_lines) unless chunk_lines.empty?
     end
     chunks
   end
 
   def warn_with_location msg
     warn msg
     warn "Message is in #{@locations}"
   end
 end
 
 class Location
   attr_reader :source
   attr_reader :info
 
   def initialize source, info
     @source = source
     @info = info
   end
 
   def raw_header
     source.raw_header info
   end
 
   def raw_message
     source.raw_message info
   end
 
   def sync_back labels, message
     synced = false
     return synced unless sync_back_enabled? and valid?
     source.synchronize do
       new_info = source.sync_back(@info, labels)
       if new_info
         @info = new_info
         Index.sync_message message, true
         synced = true
       end
     end
     synced
   end
 
   def sync_back_enabled?
     source.respond_to? :sync_back and $config[:sync_back_to_maildir] and source.sync_back_enabled?
   end
 
   ## much faster than raw_message
   def each_raw_message_line &b
     source.each_raw_message_line info, &b
   end
 
   def parsed_message
     source.load_message info
   end
 
   def fallback_date
     source.fallback_date_for_message info
   end
 
   def valid?
     source.valid? info
   end
 
   def labels?
     source.labels? info
   end
 
   def == o
     o.source.id == source.id and o.info == info
   end
 
   def hash
     [source.id, info].hash
   end
 end
 
 end