Merge branch 'develop' into release-v0.11.0

16 files changed, 378 insertions, 142 deletions

diff --git a/synapse/config/_base.py b/synapse/config/_base.py
index ceef309afc..c18e0bdbb8 100644
--- a/synapse/config/_base.py
+++ b/synapse/config/_base.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import argparse
+import errno
 import os
 import yaml
 import sys
@@ -91,8 +92,11 @@ class Config(object):
     @classmethod
     def ensure_directory(cls, dir_path):
         dir_path = cls.abspath(dir_path)
-        if not os.path.exists(dir_path):
+        try:
             os.makedirs(dir_path)
+        except OSError, e:
+            if e.errno != errno.EEXIST:
+                raise
         if not os.path.isdir(dir_path):
             raise ConfigError(
                 "%s is not a directory" % (dir_path,)
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index c0c0b693b8..d4f586fae7 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -357,7 +357,8 @@ class FederationClient(FederationBase):
         defer.returnValue(signed_auth)
 
     @defer.inlineCallbacks
-    def make_membership_event(self, destinations, room_id, user_id, membership):
+    def make_membership_event(self, destinations, room_id, user_id, membership,
+                              content={},):
         """
         Creates an m.room.member event, with context, without participating in the room.
 
@@ -398,6 +399,8 @@ class FederationClient(FederationBase):
 
                 logger.debug("Got response to make_%s: %s", membership, pdu_dict)
 
+                pdu_dict["content"].update(content)
+
                 defer.returnValue(
                     (destination, self.event_from_pdu_json(pdu_dict))
                 )
diff --git a/synapse/handlers/_base.py b/synapse/handlers/_base.py
index f4ade1f594..6519f183df 100644
--- a/synapse/handlers/_base.py
+++ b/synapse/handlers/_base.py
@@ -29,6 +29,12 @@ logger = logging.getLogger(__name__)
 
 
 class BaseHandler(object):
+    """
+    Common base class for the event handlers.
+
+    :type store: synapse.storage.events.StateStore
+    :type state_handler: synapse.state.StateHandler
+    """
 
     def __init__(self, hs):
         self.store = hs.get_datastore()
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index d1589334a5..c1bce07e31 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -564,7 +564,7 @@ class FederationHandler(BaseHandler):
 
     @log_function
     @defer.inlineCallbacks
-    def do_invite_join(self, target_hosts, room_id, joinee):
+    def do_invite_join(self, target_hosts, room_id, joinee, content):
         """ Attempts to join the `joinee` to the room `room_id` via the
         server `target_host`.
 
@@ -584,7 +584,8 @@ class FederationHandler(BaseHandler):
             target_hosts,
             room_id,
             joinee,
-            "join"
+            "join",
+            content,
         )
 
         self.room_queues[room_id] = []
@@ -840,12 +841,14 @@ class FederationHandler(BaseHandler):
         defer.returnValue(None)
 
     @defer.inlineCallbacks
-    def _make_and_verify_event(self, target_hosts, room_id, user_id, membership):
+    def _make_and_verify_event(self, target_hosts, room_id, user_id, membership,
+                               content={},):
         origin, pdu = yield self.replication_layer.make_membership_event(
             target_hosts,
             room_id,
             user_id,
-            membership
+            membership,
+            content,
         )
 
         logger.debug("Got response to make_%s: %s", membership, pdu)
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 7d31ff8d46..14051aee99 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -258,20 +258,30 @@ class MessageHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _check_in_room_or_world_readable(self, room_id, user_id, is_guest):
-        if is_guest:
+        try:
+            # check_user_was_in_room will return the most recent membership
+            # event for the user if:
+            #  * The user is a non-guest user, and was ever in the room
+            #  * The user is a guest user, and has joined the room
+            # else it will throw.
+            member_event = yield self.auth.check_user_was_in_room(room_id, user_id)
+            defer.returnValue((member_event.membership, member_event.event_id))
+            return
+        except AuthError, auth_error:
             visibility = yield self.state_handler.get_current_state(
                 room_id, EventTypes.RoomHistoryVisibility, ""
             )
-            if visibility.content["history_visibility"] == "world_readable":
+            if (
+                visibility and
+                visibility.content["history_visibility"] == "world_readable"
+            ):
                 defer.returnValue((Membership.JOIN, None))
                 return
-            else:
-                raise AuthError(
-                    403, "Guest access not allowed", errcode=Codes.GUEST_ACCESS_FORBIDDEN
-                )
-        else:
-            member_event = yield self.auth.check_user_was_in_room(room_id, user_id)
-            defer.returnValue((member_event.membership, member_event.event_id))
+            if not is_guest:
+                raise auth_error
+            raise AuthError(
+                403, "Guest access not allowed", errcode=Codes.GUEST_ACCESS_FORBIDDEN
+            )
 
     @defer.inlineCallbacks
     def get_state_events(self, user_id, room_id, is_guest=False):
@@ -456,7 +466,7 @@ class MessageHandler(BaseHandler):
         defer.returnValue(ret)
 
     @defer.inlineCallbacks
-    def room_initial_sync(self, user_id, room_id, pagin_config=None):
+    def room_initial_sync(self, user_id, room_id, pagin_config=None, is_guest=False):
         """Capture the a snapshot of a room. If user is currently a member of
         the room this will be what is currently in the room. If the user left
         the room this will be what was in the room when they left.
@@ -473,15 +483,19 @@ class MessageHandler(BaseHandler):
             A JSON serialisable dict with the snapshot of the room.
         """
 
-        member_event = yield self.auth.check_user_was_in_room(room_id, user_id)
+        membership, member_event_id = yield self._check_in_room_or_world_readable(
+            room_id,
+            user_id,
+            is_guest
+        )
 
-        if member_event.membership == Membership.JOIN:
+        if membership == Membership.JOIN:
             result = yield self._room_initial_sync_joined(
-                user_id, room_id, pagin_config, member_event
+                user_id, room_id, pagin_config, membership, is_guest
             )
-        elif member_event.membership == Membership.LEAVE:
+        elif membership == Membership.LEAVE:
             result = yield self._room_initial_sync_parted(
-                user_id, room_id, pagin_config, member_event
+                user_id, room_id, pagin_config, membership, member_event_id, is_guest
             )
 
         private_user_data = []
@@ -497,19 +511,19 @@ class MessageHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _room_initial_sync_parted(self, user_id, room_id, pagin_config,
-                                  member_event):
+                                  membership, member_event_id, is_guest):
         room_state = yield self.store.get_state_for_events(
-            [member_event.event_id], None
+            [member_event_id], None
         )
 
-        room_state = room_state[member_event.event_id]
+        room_state = room_state[member_event_id]
 
         limit = pagin_config.limit if pagin_config else None
         if limit is None:
             limit = 10
 
         stream_token = yield self.store.get_stream_token_for_event(
-            member_event.event_id
+            member_event_id
         )
 
         messages, token = yield self.store.get_recent_events_for_room(
@@ -519,7 +533,7 @@ class MessageHandler(BaseHandler):
         )
 
         messages = yield self._filter_events_for_client(
-            user_id, messages
+            user_id, messages, is_guest=is_guest
         )
 
         start_token = StreamToken(token[0], 0, 0, 0, 0)
@@ -528,7 +542,7 @@ class MessageHandler(BaseHandler):
         time_now = self.clock.time_msec()
 
         defer.returnValue({
-            "membership": member_event.membership,
+            "membership": membership,
             "room_id": room_id,
             "messages": {
                 "chunk": [serialize_event(m, time_now) for m in messages],
@@ -542,7 +556,7 @@ class MessageHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _room_initial_sync_joined(self, user_id, room_id, pagin_config,
-                                  member_event):
+                                  membership, is_guest):
         current_state = yield self.state.get_current_state(
             room_id=room_id,
         )
@@ -574,12 +588,14 @@ class MessageHandler(BaseHandler):
 
         @defer.inlineCallbacks
         def get_presence():
-            states = yield presence_handler.get_states(
-                target_users=[UserID.from_string(m.user_id) for m in room_members],
-                auth_user=auth_user,
-                as_event=True,
-                check_auth=False,
-            )
+            states = {}
+            if not is_guest:
+                states = yield presence_handler.get_states(
+                    target_users=[UserID.from_string(m.user_id) for m in room_members],
+                    auth_user=auth_user,
+                    as_event=True,
+                    check_auth=False,
+                )
 
             defer.returnValue(states.values())
 
@@ -599,7 +615,7 @@ class MessageHandler(BaseHandler):
         ).addErrback(unwrapFirstError)
 
         messages = yield self._filter_events_for_client(
-            user_id, messages
+            user_id, messages, is_guest=is_guest, require_all_visible_for_guests=False
         )
 
         start_token = now_token.copy_and_replace("room_key", token[0])
@@ -607,8 +623,7 @@ class MessageHandler(BaseHandler):
 
         time_now = self.clock.time_msec()
 
-        defer.returnValue({
-            "membership": member_event.membership,
+        ret = {
             "room_id": room_id,
             "messages": {
                 "chunk": [serialize_event(m, time_now) for m in messages],
@@ -618,4 +633,8 @@ class MessageHandler(BaseHandler):
             "state": state,
             "presence": presence,
             "receipts": receipts,
-        })
+        }
+        if not is_guest:
+            ret["membership"] = membership
+
+        defer.returnValue(ret)
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 0266926fc7..3f04752581 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -504,7 +504,8 @@ class RoomMemberHandler(BaseHandler):
             yield handler.do_invite_join(
                 room_hosts,
                 room_id,
-                event.user_id
+                event.user_id,
+                event.content,
             )
         else:
             logger.debug("Doing normal join")
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 492c1c17d5..6dc9d0fb92 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -47,9 +47,9 @@ class TimelineBatch(collections.namedtuple("TimelineBatch", [
 
 
 class JoinedSyncResult(collections.namedtuple("JoinedSyncResult", [
-    "room_id",
-    "timeline",
-    "state",
+    "room_id",           # str
+    "timeline",          # TimelineBatch
+    "state",             # dict[(str, str), FrozenEvent]
     "ephemeral",
     "private_user_data",
 ])):
@@ -68,9 +68,9 @@ class JoinedSyncResult(collections.namedtuple("JoinedSyncResult", [
 
 
 class ArchivedSyncResult(collections.namedtuple("JoinedSyncResult", [
-    "room_id",
-    "timeline",
-    "state",
+    "room_id",            # str
+    "timeline",           # TimelineBatch
+    "state",              # dict[(str, str), FrozenEvent]
     "private_user_data",
 ])):
     __slots__ = []
@@ -87,8 +87,8 @@ class ArchivedSyncResult(collections.namedtuple("JoinedSyncResult", [
 
 
 class InvitedSyncResult(collections.namedtuple("InvitedSyncResult", [
-    "room_id",
-    "invite",
+    "room_id",   # str
+    "invite",    # FrozenEvent: the invite event
 ])):
     __slots__ = []
 
@@ -254,15 +254,12 @@ class SyncHandler(BaseHandler):
             room_id, sync_config, now_token, since_token=timeline_since_token
         )
 
-        current_state = yield self.state_handler.get_current_state(
-            room_id
-        )
-        current_state_events = current_state.values()
+        current_state = yield self.get_state_at(room_id, now_token)
 
         defer.returnValue(JoinedSyncResult(
             room_id=room_id,
             timeline=batch,
-            state=current_state_events,
+            state=current_state,
             ephemeral=ephemeral_by_room.get(room_id, []),
             private_user_data=self.private_user_data_for_room(
                 room_id, tags_by_room
@@ -354,14 +351,12 @@ class SyncHandler(BaseHandler):
             room_id, sync_config, leave_token, since_token=timeline_since_token
         )
 
-        leave_state = yield self.store.get_state_for_events(
-            [leave_event_id], None
-        )
+        leave_state = yield self.store.get_state_for_event(leave_event_id)
 
         defer.returnValue(ArchivedSyncResult(
             room_id=room_id,
             timeline=batch,
-            state=leave_state[leave_event_id].values(),
+            state=leave_state,
             private_user_data=self.private_user_data_for_room(
                 room_id, tags_by_room
             ),
@@ -425,6 +420,9 @@ class SyncHandler(BaseHandler):
         if len(room_events) <= timeline_limit:
             # There is no gap in any of the rooms. Therefore we can just
             # partition the new events by room and return them.
+            logger.debug("Got %i events for incremental sync - not limited",
+                         len(room_events))
+
             invite_events = []
             leave_events = []
             events_by_room_id = {}
@@ -440,7 +438,12 @@ class SyncHandler(BaseHandler):
 
             for room_id in joined_room_ids:
                 recents = events_by_room_id.get(room_id, [])
-                state = [event for event in recents if event.is_state()]
+                logger.debug("Events for room %s: %r", room_id, recents)
+                state = {
+                    (event.type, event.state_key): event
+                    for event in recents if event.is_state()}
+                limited = False
+
                 if recents:
                     prev_batch = now_token.copy_and_replace(
                         "room_key", recents[0].internal_metadata.before
@@ -448,9 +451,13 @@ class SyncHandler(BaseHandler):
                 else:
                     prev_batch = now_token
 
-                state, limited = yield self.check_joined_room(
-                    sync_config, room_id, state
-                )
+                just_joined = yield self.check_joined_room(sync_config, state)
+                if just_joined:
+                    logger.debug("User has just joined %s: needs full state",
+                                 room_id)
+                    state = yield self.get_state_at(room_id, now_token)
+                    # the timeline is inherently limited if we've just joined
+                    limited = True
 
                 room_sync = JoinedSyncResult(
                     room_id=room_id,
@@ -465,10 +472,15 @@ class SyncHandler(BaseHandler):
                         room_id, tags_by_room
                     ),
                 )
+                logger.debug("Result for room %s: %r", room_id, room_sync)
+
                 if room_sync:
                     joined.append(room_sync)
 
         else:
+            logger.debug("Got %i events for incremental sync - hit limit",
+                         len(room_events))
+
             invite_events = yield self.store.get_invites_for_user(
                 sync_config.user.to_string()
             )
@@ -507,6 +519,9 @@ class SyncHandler(BaseHandler):
     @defer.inlineCallbacks
     def load_filtered_recents(self, room_id, sync_config, now_token,
                               since_token=None):
+        """
+        :returns a Deferred TimelineBatch
+        """
         limited = True
         recents = []
         filtering_factor = 2
@@ -558,6 +573,8 @@ class SyncHandler(BaseHandler):
         Returns:
             A Deferred JoinedSyncResult
         """
+        logger.debug("Doing incremental sync for room %s between %s and %s",
+                     room_id, since_token, now_token)
 
         # TODO(mjark): Check for redactions we might have missed.
 
@@ -567,31 +584,26 @@ class SyncHandler(BaseHandler):
 
         logging.debug("Recents %r", batch)
 
-        # TODO(mjark): This seems racy since this isn't being passed a
-        # token to indicate what point in the stream this is
-        current_state = yield self.state_handler.get_current_state(
-            room_id
-        )
-        current_state_events = current_state.values()
+        current_state = yield self.get_state_at(room_id, now_token)
 
-        state_at_previous_sync = yield self.get_state_at_previous_sync(
-            room_id, since_token=since_token
+        state_at_previous_sync = yield self.get_state_at(
+            room_id, stream_position=since_token
         )
 
-        state_events_delta = yield self.compute_state_delta(
+        state = yield self.compute_state_delta(
             since_token=since_token,
             previous_state=state_at_previous_sync,
-            current_state=current_state_events,
+            current_state=current_state,
         )
 
-        state_events_delta, _ = yield self.check_joined_room(
-            sync_config, room_id, state_events_delta
-        )
+        just_joined = yield self.check_joined_room(sync_config, state)
+        if just_joined:
+            state = yield self.get_state_at(room_id, now_token)
 
         room_sync = JoinedSyncResult(
             room_id=room_id,
             timeline=batch,
-            state=state_events_delta,
+            state=state,
             ephemeral=ephemeral_by_room.get(room_id, []),
             private_user_data=self.private_user_data_for_room(
                 room_id, tags_by_room
@@ -623,16 +635,12 @@ class SyncHandler(BaseHandler):
 
         logging.debug("Recents %r", batch)
 
-        # TODO(mjark): This seems racy since this isn't being passed a
-        # token to indicate what point in the stream this is
-        leave_state = yield self.store.get_state_for_events(
-            [leave_event.event_id], None
+        state_events_at_leave = yield self.store.get_state_for_event(
+            leave_event.event_id
         )
 
-        state_events_at_leave = leave_state[leave_event.event_id].values()
-
-        state_at_previous_sync = yield self.get_state_at_previous_sync(
-            leave_event.room_id, since_token=since_token
+        state_at_previous_sync = yield self.get_state_at(
+            leave_event.room_id, stream_position=since_token
         )
 
         state_events_delta = yield self.compute_state_delta(
@@ -655,60 +663,77 @@ class SyncHandler(BaseHandler):
         defer.returnValue(room_sync)
 
     @defer.inlineCallbacks
-    def get_state_at_previous_sync(self, room_id, since_token):
-        """ Get the room state at the previous sync the client made.
-        Returns:
-            A Deferred list of Events.
+    def get_state_after_event(self, event):
+        """
+        Get the room state after the given event
+
+        :param synapse.events.EventBase event: event of interest
+        :return: A Deferred map from ((type, state_key)->Event)
+        """
+        state = yield self.store.get_state_for_event(event.event_id)
+        if event.is_state():
+            state = state.copy()
+            state[(event.type, event.state_key)] = event
+        defer.returnValue(state)
+
+    @defer.inlineCallbacks
+    def get_state_at(self, room_id, stream_position):
+        """ Get the room state at a particular stream position
+        :param str room_id: room for which to get state
+        :param StreamToken stream_position: point at which to get state
+        :returns: A Deferred map from ((type, state_key)->Event)
         """
         last_events, token = yield self.store.get_recent_events_for_room(
-            room_id, end_token=since_token.room_key, limit=1,
+            room_id, end_token=stream_position.room_key, limit=1,
         )
 
         if last_events:
-            last_event = last_events[0]
-            last_context = yield self.state_handler.compute_event_context(
-                last_event
-            )
-            if last_event.is_state():
-                state = [last_event] + last_context.current_state.values()
-            else:
-                state = last_context.current_state.values()
+            last_event = last_events[-1]
+            state = yield self.get_state_after_event(last_event)
+
         else:
-            state = ()
+            # no events in this room - so presumably no state
+            state = {}
         defer.returnValue(state)
 
     def compute_state_delta(self, since_token, previous_state, current_state):
         """ Works out the differnce in state between the current state and the
         state the client got when it last performed a sync.
-        Returns:
-            A list of events.
+
+        :param str since_token: the point we are comparing against
+        :param dict[(str,str), synapse.events.FrozenEvent] previous_state: the
+            state to compare to
+        :param dict[(str,str), synapse.events.FrozenEvent] current_state: the
+            new state
+
+        :returns A new event dictionary
         """
         # TODO(mjark) Check if the state events were received by the server
         # after the previous sync, since we need to include those state
         # updates even if they occured logically before the previous event.
         # TODO(mjark) Check for new redactions in the state events.
-        previous_dict = {event.event_id: event for event in previous_state}
-        state_delta = []
-        for event in current_state:
-            if event.event_id not in previous_dict:
-                state_delta.append(event)
+
+        state_delta = {}
+        for key, event in current_state.iteritems():
+            if (key not in previous_state or
+                    previous_state[key].event_id != event.event_id):
+                state_delta[key] = event
         return state_delta
 
-    @defer.inlineCallbacks
-    def check_joined_room(self, sync_config, room_id, state_delta):
-        joined = False
-        limited = False
-        for event in state_delta:
-            if (
-                event.type == EventTypes.Member
-                and event.state_key == sync_config.user.to_string()
-            ):
-                if event.content["membership"] == Membership.JOIN:
-                    joined = True
-
-        if joined:
-            res = yield self.state_handler.get_current_state(room_id)
-            state_delta = res.values()
-            limited = True
+    def check_joined_room(self, sync_config, state_delta):
+        """
+        Check if the user has just joined the given room (so should
+        be given the full state)
 
-        defer.returnValue((state_delta, limited))
+        :param sync_config:
+        :param dict[(str,str), synapse.events.FrozenEvent] state_delta: the
+           difference in state since the last sync
+
+        :returns A deferred Tuple (state_delta, limited)
+        """
+        join_event = state_delta.get((
+            EventTypes.Member, sync_config.user.to_string()), None)
+        if join_event is not None:
+            if join_event.content["membership"] == Membership.JOIN:
+                return True
+        return False
diff --git a/synapse/notifier.py b/synapse/notifier.py
index 56c4c863b5..e3b42e2331 100644
--- a/synapse/notifier.py
+++ b/synapse/notifier.py
@@ -14,6 +14,8 @@
 # limitations under the License.
 
 from twisted.internet import defer
+from synapse.api.constants import EventTypes
+from synapse.api.errors import AuthError
 
 from synapse.util.logutils import log_function
 from synapse.util.async import run_on_reactor, ObservableDeferred
@@ -346,9 +348,9 @@ class Notifier(object):
 
         room_ids = []
         if is_guest:
-            # TODO(daniel): Deal with non-room events too
-            only_room_events = True
             if guest_room_id:
+                if not self._is_world_readable(guest_room_id):
+                    raise AuthError(403, "Guest access not allowed")
                 room_ids = [guest_room_id]
         else:
             rooms = yield self.store.get_rooms_for_user(user.to_string())
@@ -361,6 +363,7 @@ class Notifier(object):
 
             events = []
             end_token = from_token
+
             for name, source in self.event_sources.sources.items():
                 keyname = "%s_key" % name
                 before_id = getattr(before_token, keyname)
@@ -377,7 +380,7 @@ class Notifier(object):
                     room_ids=room_ids,
                 )
 
-                if is_guest:
+                if name == "room":
                     room_member_handler = self.hs.get_handlers().room_member_handler
                     new_events = yield room_member_handler._filter_events_for_client(
                         user.to_string(),
@@ -403,6 +406,17 @@ class Notifier(object):
 
         defer.returnValue(result)
 
+    @defer.inlineCallbacks
+    def _is_world_readable(self, room_id):
+        state = yield self.hs.get_state_handler().get_current_state(
+            room_id,
+            EventTypes.RoomHistoryVisibility
+        )
+        if state and "history_visibility" in state.content:
+            defer.returnValue(state.content["history_visibility"] == "world_readable")
+        else:
+            defer.returnValue(False)
+
     @log_function
     def remove_expired_streams(self):
         time_now_ms = self.clock.time_msec()
diff --git a/synapse/rest/client/v1/profile.py b/synapse/rest/client/v1/profile.py
index 6b379e4e5f..3218e47025 100644
--- a/synapse/rest/client/v1/profile.py
+++ b/synapse/rest/client/v1/profile.py
@@ -37,7 +37,7 @@ class ProfileDisplaynameRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_PUT(self, request, user_id):
-        auth_user, _, _ = yield self.auth.get_user_by_req(request)
+        auth_user, _, _ = yield self.auth.get_user_by_req(request, allow_guest=True)
         user = UserID.from_string(user_id)
 
         try:
diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py
index c583025e30..d298aee3ab 100644
--- a/synapse/rest/client/v1/room.py
+++ b/synapse/rest/client/v1/room.py
@@ -372,12 +372,13 @@ class RoomInitialSyncRestServlet(ClientV1RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, room_id):
-        user, _, _ = yield self.auth.get_user_by_req(request)
+        user, _, is_guest = yield self.auth.get_user_by_req(request, allow_guest=True)
         pagination_config = PaginationConfig.from_request(request)
         content = yield self.handlers.message_handler.room_initial_sync(
             room_id=room_id,
             user_id=user.to_string(),
             pagin_config=pagination_config,
+            is_guest=is_guest,
         )
         defer.returnValue((200, content))
 
diff --git a/synapse/rest/client/v2_alpha/sync.py b/synapse/rest/client/v2_alpha/sync.py
index d24507effa..efd8281558 100644
--- a/synapse/rest/client/v2_alpha/sync.py
+++ b/synapse/rest/client/v2_alpha/sync.py
@@ -20,6 +20,7 @@ from synapse.http.servlet import (
 )
 from synapse.handlers.sync import SyncConfig
 from synapse.types import StreamToken
+from synapse.events import FrozenEvent
 from synapse.events.utils import (
     serialize_event, format_event_for_client_v2_without_event_id,
 )
@@ -165,6 +166,20 @@ class SyncRestServlet(RestServlet):
         return {"events": filter.filter_presence(formatted)}
 
     def encode_joined(self, rooms, filter, time_now, token_id):
+        """
+        Encode the joined rooms in a sync result
+
+        :param list[synapse.handlers.sync.JoinedSyncResult] rooms: list of sync
+            results for rooms this user is joined to
+        :param FilterCollection filter: filters to apply to the results
+        :param int time_now: current time - used as a baseline for age
+            calculations
+        :param int token_id: ID of the user's auth token - used for namespacing
+            of transaction IDs
+
+        :return: the joined rooms list, in our response format
+        :rtype: dict[str, dict[str, object]]
+        """
         joined = {}
         for room in rooms:
             joined[room.room_id] = self.encode_room(
@@ -174,6 +189,20 @@ class SyncRestServlet(RestServlet):
         return joined
 
     def encode_invited(self, rooms, filter, time_now, token_id):
+        """
+        Encode the invited rooms in a sync result
+
+        :param list[synapse.handlers.sync.InvitedSyncResult] rooms: list of
+             sync results for rooms this user is joined to
+        :param FilterCollection filter: filters to apply to the results
+        :param int time_now: current time - used as a baseline for age
+            calculations
+        :param int token_id: ID of the user's auth token - used for namespacing
+            of transaction IDs
+
+        :return: the invited rooms list, in our response format
+        :rtype: dict[str, dict[str, object]]
+        """
         invited = {}
         for room in rooms:
             invite = serialize_event(
@@ -189,6 +218,20 @@ class SyncRestServlet(RestServlet):
         return invited
 
     def encode_archived(self, rooms, filter, time_now, token_id):
+        """
+        Encode the archived rooms in a sync result
+
+        :param list[synapse.handlers.sync.ArchivedSyncResult] rooms: list of
+             sync results for rooms this user is joined to
+        :param FilterCollection filter: filters to apply to the results
+        :param int time_now: current time - used as a baseline for age
+            calculations
+        :param int token_id: ID of the user's auth token - used for namespacing
+            of transaction IDs
+
+        :return: the invited rooms list, in our response format
+        :rtype: dict[str, dict[str, object]]
+        """
         joined = {}
         for room in rooms:
             joined[room.room_id] = self.encode_room(
@@ -199,8 +242,28 @@ class SyncRestServlet(RestServlet):
 
     @staticmethod
     def encode_room(room, filter, time_now, token_id, joined=True):
+        """
+        :param JoinedSyncResult|ArchivedSyncResult room: sync result for a
+            single room
+        :param FilterCollection filter: filters to apply to the results
+        :param int time_now: current time - used as a baseline for age
+            calculations
+        :param int token_id: ID of the user's auth token - used for namespacing
+            of transaction IDs
+        :param joined: True if the user is joined to this room - will mean
+            we handle ephemeral events
+
+        :return: the room, encoded in our response format
+        :rtype: dict[str, object]
+        """
         event_map = {}
-        state_events = filter.filter_room_state(room.state)
+        state_dict = room.state
+        timeline_events = filter.filter_room_timeline(room.timeline.events)
+
+        state_dict = SyncRestServlet._rollback_state_for_timeline(
+            state_dict, timeline_events)
+
+        state_events = filter.filter_room_state(state_dict.values())
         state_event_ids = []
         for event in state_events:
             # TODO(mjark): Respect formatting requirements in the filter.
@@ -210,7 +273,6 @@ class SyncRestServlet(RestServlet):
             )
             state_event_ids.append(event.event_id)
 
-        timeline_events = filter.filter_room_timeline(room.timeline.events)
         timeline_event_ids = []
         for event in timeline_events:
             # TODO(mjark): Respect formatting requirements in the filter.
@@ -241,6 +303,63 @@ class SyncRestServlet(RestServlet):
 
         return result
 
+    @staticmethod
+    def _rollback_state_for_timeline(state, timeline):
+        """
+        Wind the state dictionary backwards, so that it represents the
+        state at the start of the timeline, rather than at the end.
+
+        :param dict[(str, str), synapse.events.EventBase] state: the
+            state dictionary. Will be updated to the state before the timeline.
+        :param list[synapse.events.EventBase] timeline: the event timeline
+        :return: updated state dictionary
+        """
+        logger.debug("Processing state dict %r; timeline %r", state,
+                     [e.get_dict() for e in timeline])
+
+        result = state.copy()
+
+        for timeline_event in reversed(timeline):
+            if not timeline_event.is_state():
+                continue
+
+            event_key = (timeline_event.type, timeline_event.state_key)
+
+            logger.debug("Considering %s for removal", event_key)
+
+            state_event = result.get(event_key)
+            if (state_event is None or
+                    state_event.event_id != timeline_event.event_id):
+                # the event in the timeline isn't present in the state
+                # dictionary.
+                #
+                # the most likely cause for this is that there was a fork in
+                # the event graph, and the state is no longer valid. Really,
+                # the event shouldn't be in the timeline. We're going to ignore
+                # it for now, however.
+                logger.warn("Found state event %r in timeline which doesn't "
+                            "match state dictionary", timeline_event)
+                continue
+
+            prev_event_id = timeline_event.unsigned.get("replaces_state", None)
+            logger.debug("Replacing %s with %s in state dict",
+                         timeline_event.event_id, prev_event_id)
+
+            if prev_event_id is None:
+                del result[event_key]
+            else:
+                result[event_key] = FrozenEvent({
+                    "type": timeline_event.type,
+                    "state_key": timeline_event.state_key,
+                    "content": timeline_event.unsigned['prev_content'],
+                    "sender": timeline_event.unsigned['prev_sender'],
+                    "event_id": prev_event_id,
+                    "room_id": timeline_event.room_id,
+                })
+            logger.debug("New value: %r", result.get(event_key))
+
+        return result
+
 
 def register_servlets(hs, http_server):
     SyncRestServlet(hs).register(http_server)
diff --git a/synapse/state.py b/synapse/state.py
index bb225c39cf..8ea2cac5d6 100644
--- a/synapse/state.py
+++ b/synapse/state.py
@@ -71,7 +71,7 @@ class StateHandler(object):
 
     @defer.inlineCallbacks
     def get_current_state(self, room_id, event_type=None, state_key=""):
-        """ Returns the current state for the room as a list. This is done by
+        """ Retrieves the current state for the room. This is done by
         calling `get_latest_events_in_room` to get the leading edges of the
         event graph and then resolving any of the state conflicts.
 
@@ -80,6 +80,8 @@ class StateHandler(object):
 
         If `event_type` is specified, then the method returns only the one
         event (or None) with that `event_type` and `state_key`.
+
+        :returns map from (type, state_key) to event
         """
         event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
 
@@ -177,9 +179,10 @@ class StateHandler(object):
         """ Given a list of event_ids this method fetches the state at each
         event, resolves conflicts between them and returns them.
 
-        Return format is a tuple: (`state_group`, `state_events`), where the
-        first is the name of a state group if one and only one is involved,
-        otherwise `None`.
+        :returns a Deferred tuple of (`state_group`, `state`, `prev_state`).
+        `state_group` is the name of a state group if one and only one is
+        involved. `state` is a map from (type, state_key) to event, and
+        `prev_state` is a list of event ids.
         """
         logger.debug("resolve_state_groups event_ids %s", event_ids)
 
@@ -255,6 +258,11 @@ class StateHandler(object):
             return self._resolve_events(state_sets)
 
     def _resolve_events(self, state_sets, event_type=None, state_key=""):
+        """
+        :returns a tuple (new_state, prev_states). new_state is a map
+        from (type, state_key) to event. prev_states is a list of event_ids.
+        :rtype: (dict[(str, str), synapse.events.FrozenEvent], list[str])
+        """
         state = {}
         for st in state_sets:
             for e in st:
@@ -307,19 +315,23 @@ class StateHandler(object):
 
         We resolve conflicts in the following order:
             1. power levels
-            2. memberships
-            3. other events.
+            2. join rules
+            3. memberships
+            4. other events.
         """
         resolved_state = {}
         power_key = (EventTypes.PowerLevels, "")
-        if power_key in conflicted_state.items():
-            power_levels = conflicted_state[power_key]
-            resolved_state[power_key] = self._resolve_auth_events(power_levels)
+        if power_key in conflicted_state:
+            events = conflicted_state[power_key]
+            logger.debug("Resolving conflicted power levels %r", events)
+            resolved_state[power_key] = self._resolve_auth_events(
+                events, auth_events)
 
         auth_events.update(resolved_state)
 
         for key, events in conflicted_state.items():
             if key[0] == EventTypes.JoinRules:
+                logger.debug("Resolving conflicted join rules %r", events)
                 resolved_state[key] = self._resolve_auth_events(
                     events,
                     auth_events
@@ -329,6 +341,7 @@ class StateHandler(object):
 
         for key, events in conflicted_state.items():
             if key[0] == EventTypes.Member:
+                logger.debug("Resolving conflicted member lists %r", events)
                 resolved_state[key] = self._resolve_auth_events(
                     events,
                     auth_events
@@ -338,6 +351,7 @@ class StateHandler(object):
 
         for key, events in conflicted_state.items():
             if key not in resolved_state:
+                logger.debug("Resolving conflicted state %r:%r", key, events)
                 resolved_state[key] = self._resolve_normal_events(
                     events, auth_events
                 )
diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 4a365ff639..5d35ca90b9 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -831,7 +831,8 @@ class EventsStore(SQLBaseStore):
                 allow_none=True,
             )
             if prev:
-                ev.unsigned["prev_content"] = prev.get_dict()["content"]
+                ev.unsigned["prev_content"] = prev.content
+                ev.unsigned["prev_sender"] = prev.sender
 
         self._get_event_cache.prefill(
             (ev.event_id, check_redacted, get_prev_content), ev
@@ -888,7 +889,8 @@ class EventsStore(SQLBaseStore):
                 get_prev_content=False,
             )
             if prev:
-                ev.unsigned["prev_content"] = prev.get_dict()["content"]
+                ev.unsigned["prev_content"] = prev.content
+                ev.unsigned["prev_sender"] = prev.sender
 
         self._get_event_cache.prefill(
             (ev.event_id, check_redacted, get_prev_content), ev
diff --git a/synapse/storage/search.py b/synapse/storage/search.py
index 2e88c51ad0..380270b009 100644
--- a/synapse/storage/search.py
+++ b/synapse/storage/search.py
@@ -252,12 +252,23 @@ class SearchStore(BackgroundUpdateStore):
                 " WHERE vector @@ query AND room_id = ?"
             )
         elif isinstance(self.database_engine, Sqlite3Engine):
+            # We use CROSS JOIN here to ensure we use the right indexes.
+            # https://sqlite.org/optoverview.html#crossjoin
+            #
+            # We want to use the full text search index on event_search to
+            # extract all possible matches first, then lookup those matches
+            # in the events table to get the topological ordering. We need
+            # to use the indexes in this order because sqlite refuses to
+            # MATCH unless it uses the full text search index
             sql = (
-                "SELECT rank(matchinfo(event_search)) as rank, room_id, event_id,"
+                "SELECT rank(matchinfo) as rank, room_id, event_id,"
                 " topological_ordering, stream_ordering"
+                " FROM (SELECT key, event_id, matchinfo(event_search) as matchinfo"
                 " FROM event_search"
-                " NATURAL JOIN events"
-                " WHERE value MATCH ? AND room_id = ?"
+                " WHERE value MATCH ?"
+                " )"
+                " CROSS JOIN events USING (event_id)"
+                " WHERE room_id = ?"
             )
         else:
             # This should be unreachable.
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index acfb322a53..80e9b63f50 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -237,6 +237,20 @@ class StateStore(SQLBaseStore):
 
         defer.returnValue({event: event_to_state[event] for event in event_ids})
 
+    @defer.inlineCallbacks
+    def get_state_for_event(self, event_id, types=None):
+        """
+        Get the state dict corresponding to a particular event
+
+        :param str event_id: event whose state should be returned
+        :param list[(str, str)]|None types: List of (type, state_key) tuples
+            which are used to filter the state fetched. May be None, which
+            matches any key
+        :return: a deferred dict from (type, state_key) -> state_event
+        """
+        state_map = yield self.get_state_for_events([event_id], types)
+        defer.returnValue(state_map[event_id])
+
     @cached(num_args=2, lru=True, max_entries=10000)
     def _get_state_group_for_event(self, room_id, event_id):
         return self._simple_select_one_onecol(
diff --git a/synapse/storage/transactions.py b/synapse/storage/transactions.py
index 4e0d7c9774..ad099775eb 100644
--- a/synapse/storage/transactions.py
+++ b/synapse/storage/transactions.py
@@ -59,7 +59,7 @@ class TransactionStore(SQLBaseStore):
             allow_none=True,
         )
 
-        if result and result.response_code:
+        if result and result["response_code"]:
             return result["response_code"], result["response_json"]
         else:
             return None