+ ## write the new document to the index. if the entry already exists in the
+ ## index, reuse it (which avoids having to reload the entry from the source,
+ ## which can be quite expensive for e.g. large threads of IMAP actions.)
+ ##
+ ## exception: if the index entry belongs to an earlier version of the
+ ## message, use everything from the new message instead, but union the
+ ## flags. this allows messages sent to mailing lists to have their header
+ ## updated and to have flags set properly.
+ ##
+ ## minor hack: messages in sources with lower ids have priority over
+ ## messages in sources with higher ids. so messages in the inbox will
+ ## override everyone, and messages in the sent box will be overridden
+ ## by everyone else.
+ ##
+ ## written in this manner to support previous versions of the index which
+ ## did not keep around the entry body. upgrading is thus seamless.
+ entry ||= {}
+ labels = m.labels.uniq # override because this is the new state, unless...
+
+ ## if we are a later version of a message, ignore what's in the index,
+ ## but merge in the labels.
+ if entry[:source_id] && entry[:source_info] && entry[:label] &&
+ ((entry[:source_id].to_i > source_id) || (entry[:source_info].to_i < m.source_info))
+ labels = (entry[:label].split(/\s+/).map { |l| l.intern } + m.labels).uniq
+ #Redwood::log "found updated version of message #{m.id}: #{m.subj}"
+ #Redwood::log "previous version was at #{entry[:source_id].inspect}:#{entry[:source_info].inspect}, this version at #{source_id.inspect}:#{m.source_info.inspect}"
+ #Redwood::log "merged labels are #{labels.inspect} (index #{entry[:label].inspect}, message #{m.labels.inspect})"
+ entry = {}
+ end
+
+ ## if force_overwite is true, ignore what's in the index. this is used
+ ## primarily by sup-sync to force index updates.
+ entry = {} if opts[:force_overwrite]
+