From 09ba5ee455bda97604d2c6b8610dc7b1166dd828 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 16 Apr 2020 15:45:07 -0700
Subject: [PATCH] ircd::m::join: Unify condition for bootstrap; fix bootstrap
 on invite.

---
 matrix/room_join.cc | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/matrix/room_join.cc b/matrix/room_join.cc
index 2cc448abb..5caa6cd6a 100644
--- a/matrix/room_join.cc
+++ b/matrix/room_join.cc
@@ -8,6 +8,11 @@
 // copyright notice and this permission notice is present in all copies. The
 // full license for this software is available in the LICENSE file.
 
+namespace ircd::m
+{
+	static bool need_bootstrap(const room::id &);
+}
+
 ircd::m::event::id::buf
 ircd::m::join(const room::alias &room_alias,
               const user::id &user_id)
@@ -23,7 +28,7 @@ ircd::m::join(const room::alias &room_alias,
 		m::room_id(room_alias)
 	};
 
-	if(!exists(room_id))
+	if(need_bootstrap(room_id))
 	{
 		m::event::id::buf ret;
 		m::room::bootstrap
@@ -53,7 +58,7 @@ ircd::m::join(const m::room &room,
 		};
 
 	// Branch for when nothing is known about the room.
-	if(!exists(room))
+	if(need_bootstrap(room))
 	{
 		// The bootstrap condcts a blocking make_join and issues a join
 		// event, returning the event_id; afterward asynchronously it will
@@ -135,3 +140,19 @@ ircd::m::join(const m::room &room,
 
 	return commit(room, event, content);
 }
+
+bool
+ircd::m::need_bootstrap(const room::id &room_id)
+{
+	// We have nothing for the room
+	if(!exists(room_id))
+		return true;
+
+	// No users are currently joined from this server;
+	//TODO: bootstrap shouldn't have to be used to re-sync a room where we have
+	//TODO: some partial state, so this condition should be eliminated.
+	if(local_joined(room_id) == 0)
+		return true;
+
+	return false;
+}