From 7027f671c35f4b22c6af5ff0b1a58f79a34d41d0 Mon Sep 17 00:00:00 2001
From: William Morgan <wmorgan-sup@masanjin.net>
Date: Wed, 16 Jan 2008 16:44:43 -0800
Subject: [PATCH] add the ability to joining threads forcefully to ThreadSet

ThreadSet#join_threads now takes any number of threads (which must be part
of the threadset) heuristically either picks one message to be the root
(if all messages but one have a "Re:" on the subject line), or creates
a fake root. It updates the message object and marks it dirty so that a
subsequent save will preserve the new structure.
---
 lib/sup/message.rb | 17 ++++++++++++++++-
 lib/sup/thread.rb  | 26 ++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/lib/sup/message.rb b/lib/sup/message.rb
index c487ae3..651c839 100644
--- a/lib/sup/message.rb
+++ b/lib/sup/message.rb
@@ -55,6 +55,10 @@ class Message
     @encrypted = false
     @chunks = nil
 
+    ## we need to initialize this. see comments in parse_header as to
+    ## why.
+    @refs = []
+
     parse_header(opts[:header] || @source.load_header(@source_info))
   end
 
@@ -102,7 +106,13 @@ class Message
     @to = PersonManager.people_for header["to"]
     @cc = PersonManager.people_for header["cc"]
     @bcc = PersonManager.people_for header["bcc"]
-    @refs = (header["references"] || "").scan(/<(.+?)>/).map { |x| sanitize_message_id x.first }
+
+    ## 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 = PersonManager.person_for header["reply-to"]
@@ -120,6 +130,11 @@ class Message
   end
   private :parse_header
 
+  def add_ref ref
+    @refs << ref
+    @dirty = true
+  end
+
   def snippet; @snippet || (chunks && @snippet); end
   def is_list_message?; !@list_address.nil?; end
   def is_draft?; @source.is_a? DraftLoader; end
diff --git a/lib/sup/thread.rb b/lib/sup/thread.rb
index 3ade024..32002c4 100644
--- a/lib/sup/thread.rb
+++ b/lib/sup/thread.rb
@@ -349,6 +349,32 @@ class ThreadSet
     t.each { |m, *o| add_message m }
   end
 
+  ## merges two threads together. both must be members of this threadset.
+  ## does its best, heuristically, to determine which is the parent.
+  def join_threads threads
+    return if threads.size < 2
+
+    containers = threads.map do |t|
+      c = @messages[t.first.id]
+      raise "not in threadset: #{t.first.id}" unless c && c.message
+      c
+    end
+
+    ## use subject headers heuristically
+    parent = containers.find { |c| !c.is_reply? }
+
+    ## no thread was rooted by a non-reply, so make a fake parent
+    parent ||= @messages["joining-ref-" + containers.map { |c| c.id }.join("-")]
+
+    containers.each do |c|
+      next if c == parent
+      c.message.add_ref parent.id
+      link parent, c
+    end
+
+    true
+  end
+
   def is_relevant? m
     m.refs.any? { |ref_id| @messages.member? ref_id }
   end
-- 
2.45.2