From: Jesse Rosenthal <jrosenthal@jhu.edu>
To: notmuch@notmuchmail.org
Date: Mon, 22 Mar 2010 23:09:15 -0400
Message-ID: <87sk7rloo4.fsf@jhu.edu>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Subject: [notmuch] [PATCH] Name thread based on matching msgs instead of
	first msg.
Precedence: list


At the moment all threads are named based on the name of the first message
in the thread. However, this can cause problems if people either start
new threads by replying-all (as unfortunately, many out there do) or
change the subject of their mails to reflect a shift in a thread on a
list.

This patch names threads based on matches for the query, and the search
order. If the search order is oldest-first (as in the default inbox) it
chooses the oldest matching message as the subject. If the search order is
newest-first it chooses the newest one.

Reply prefixes ("Re: ", "Aw: ", "Sv: ", "Vs: ") are ignored
(case-insensitively) so a Re: won't change the subject.

Note that this adds a "sort" argument to _notmuch_thread_create and
_thread_add_matched_message, so that when constructing the thread we can
be aware of the sort order.
---
 lib/notmuch-private.h |    3 ++-
 lib/query.cc          |    3 ++-
 lib/thread.cc         |   30 +++++++++++++++++++++++++++---
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index d52d84d..94cce1b 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -205,7 +205,8 @@ notmuch_thread_t *
 _notmuch_thread_create (void *ctx,
 			notmuch_database_t *notmuch,
 			const char *thread_id,
-			const char *query_string);
+			const char *query_string,
+			notmuch_sort_t sort);
 
 /* message.cc */
 
diff --git a/lib/query.cc b/lib/query.cc
index 9266d35..946f367 100644
--- a/lib/query.cc
+++ b/lib/query.cc
@@ -297,7 +297,8 @@ notmuch_threads_get (notmuch_threads_t *threads)
     return _notmuch_thread_create (threads->query,
 				   threads->query->notmuch,
 				   threads->thread_id,
-				   threads->query->query_string);
+				   threads->query->query_string,
+				   threads->query->sort);
 }
 
 void
diff --git a/lib/thread.cc b/lib/thread.cc
index ec80f85..9ba7b70 100644
--- a/lib/thread.cc
+++ b/lib/thread.cc
@@ -129,7 +129,8 @@ _thread_add_message (notmuch_thread_t *thread,
 
 static void
 _thread_add_matched_message (notmuch_thread_t *thread,
-			     notmuch_message_t *message)
+			     notmuch_message_t *message,
+			     notmuch_sort_t sort)
 {
     time_t date;
     notmuch_message_t *hashed_message;
@@ -142,6 +143,28 @@ _thread_add_matched_message (notmuch_thread_t *thread,
     if (date > thread->newest || ! thread->matched_messages)
 	thread->newest = date;
 
+    const char *subject;
+    const char *cleaned_subject;
+
+    subject = notmuch_message_get_header (message, "subject");
+
+    if ((strncasecmp (subject, "Re: ", 4) == 0) ||
+	(strncasecmp (subject, "Aw: ", 4) == 0) ||
+	(strncasecmp (subject, "Vs: ", 4) == 0) ||
+	(strncasecmp (subject, "Sv: ", 4) == 0)) {
+
+	cleaned_subject = talloc_strndup (thread,
+					  subject + 4,
+					  strlen(subject) - 4);
+    } else {
+	cleaned_subject = talloc_strdup (thread, subject);
+    }
+
+    if ((sort == NOTMUCH_SORT_OLDEST_FIRST && date <= thread->newest) ||
+	(sort != NOTMUCH_SORT_OLDEST_FIRST && date == thread->newest)) {
+	thread->subject = talloc_strdup (thread, cleaned_subject);
+    }
+
     thread->matched_messages++;
 
     if (g_hash_table_lookup_extended (thread->message_hash,
@@ -209,7 +232,8 @@ notmuch_thread_t *
 _notmuch_thread_create (void *ctx,
 			notmuch_database_t *notmuch,
 			const char *thread_id,
-			const char *query_string)
+			const char *query_string,
+			notmuch_sort_t sort)
 {
     notmuch_thread_t *thread;
     const char *thread_id_query_string, *matched_query_string;
@@ -284,7 +308,7 @@ _notmuch_thread_create (void *ctx,
 	 notmuch_messages_move_to_next (messages))
     {
 	message = notmuch_messages_get (messages);
-	_thread_add_matched_message (thread, message);
+	_thread_add_matched_message (thread, message, sort);
 	_notmuch_message_close (message);
     }
 
-- 
1.6.3.3