From 7723b4caa4a1d4e0ee252165dcfaf910bda31ef2 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 8 Feb 2017 14:48:06 +0000
Subject: [PATCH 1/2] Ignore new rejected events when working out forward
 extremeties.

---
 synapse/storage/events.py | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 8659f605a..c88f689d3 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -302,7 +302,7 @@ class EventsStore(SQLBaseStore):
                                 room_id
                             )
                             new_latest_event_ids = yield self._calculate_new_extremeties(
-                                room_id, [ev for ev, _ in ev_ctx_rm]
+                                room_id, ev_ctx_rm, latest_event_ids
                             )
 
                             if new_latest_event_ids == set(latest_event_ids):
@@ -329,27 +329,24 @@ class EventsStore(SQLBaseStore):
                 persist_event_counter.inc_by(len(chunk))
 
     @defer.inlineCallbacks
-    def _calculate_new_extremeties(self, room_id, events):
+    def _calculate_new_extremeties(self, room_id, event_contexts, latest_event_ids):
         """Calculates the new forward extremeties for a room given events to
         persist.
 
         Assumes that we are only persisting events for one room at a time.
         """
-        latest_event_ids = yield self.get_latest_event_ids_in_room(
-            room_id
-        )
         new_latest_event_ids = set(latest_event_ids)
         # First, add all the new events to the list
         new_latest_event_ids.update(
-            event.event_id for event in events
-            if not event.internal_metadata.is_outlier()
+            event.event_id for event, ctx in event_contexts
+            if not event.internal_metadata.is_outlier() and not ctx.rejected
         )
         # Now remove all events that are referenced by the to-be-added events
         new_latest_event_ids.difference_update(
             e_id
-            for event in events
+            for event, ctx in event_contexts
             for e_id, _ in event.prev_events
-            if not event.internal_metadata.is_outlier()
+            if not event.internal_metadata.is_outlier() and not ctx.rejected
         )
 
         # And finally remove any events that are referenced by previously added

From 505bfd82bbf1ff51e8f08a98c72b9d214a269d33 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 9 Feb 2017 10:41:02 +0000
Subject: [PATCH 2/2] Update version and changelog

---
 CHANGES.rst         | 7 +++++++
 synapse/__init__.py | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index da241666d..22aa7cb9b 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,3 +1,10 @@
+Changes in synapse v0.19.1 (2017-02-09)
+=======================================
+
+* Fix bug where state was incorrectly reset in a room when synapse received an
+  event over federation that did not pass auth checks (PR #1892)
+
+
 Changes in synapse v0.19.0 (2017-02-04)
 =======================================
 
diff --git a/synapse/__init__.py b/synapse/__init__.py
index d3f445be9..da8ef90a7 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -16,4 +16,4 @@
 """ This is a reference implementation of a Matrix home server.
 """
 
-__version__ = "0.19.0"
+__version__ = "0.19.1"