Merge branch 'develop' of github.com:matrix-org/synapse into postgres

24 files changed, 642 insertions, 391 deletions

diff --git a/README.rst b/README.rst
index 14ef6c5acf..714ad6443d 100644
--- a/README.rst
+++ b/README.rst
@@ -86,7 +86,7 @@ Homeserver Installation
 =======================
 
 System requirements:
-- POSIX-compliant system (tested on Linux & OSX)
+- POSIX-compliant system (tested on Linux & OS X)
 - Python 2.7
 
 Synapse is written in python but some of the libraries is uses are written in
@@ -128,6 +128,15 @@ To set up your homeserver, run (in your virtualenv, as before)::
 
 Substituting your host and domain name as appropriate.
 
+This will generate you a config file that you can then customise, but it will
+also generate a set of keys for you. These keys will allow your Home Server to
+identify itself to other Home Servers, so don't lose or delete them. It would be
+wise to back them up somewhere safe. If, for whatever reason, you do need to
+change your Home Server's keys, you may find that other Home Servers have the
+old key cached. If you update the signing key, you should change the name of the
+key in the <server name>.signing.key file (the second word, which by default is
+, 'auto') to something different.
+
 By default, registration of new users is disabled. You can either enable
 registration in the config by specifying ``enable_registration: true``
 (it is then recommended to also set up CAPTCHA), or
@@ -367,10 +376,6 @@ SRV record, as that is the name other machines will expect it to have::
 You may additionally want to pass one or more "-v" options, in order to
 increase the verbosity of logging output; at least for initial testing.
 
-For the initial alpha release, the homeserver is not speaking TLS for
-either client-server or server-server traffic for ease of debugging. We have
-also not spent any time yet getting the homeserver to run behind loadbalancers.
-
 Running a Demo Federation of Homeservers
 ----------------------------------------
 
@@ -433,7 +438,7 @@ track 3PID logins and publish end-user public keys.
 
 It's currently early days for identity servers as Matrix is not yet using 3PIDs
 as the primary means of identity and E2E encryption is not complete. As such,
-we are running a single identity server (http://matrix.org:8090) at the current
+we are running a single identity server (https://matrix.org) at the current
 time.
 
 
diff --git a/UPGRADE.rst b/UPGRADE.rst
index 87dd6e04a8..ab327a8136 100644
--- a/UPGRADE.rst
+++ b/UPGRADE.rst
@@ -1,3 +1,37 @@
+Upgrading to v0.x.x
+===================
+
+Application services have had a breaking API change in this version.
+
+They can no longer register themselves with a home server using the AS HTTP API. This
+decision was made because a compromised application service with free reign to register
+any regex in effect grants full read/write access to the home server if a regex of ``.*``
+is used. An attack where a compromised AS re-registers itself with ``.*`` was deemed too
+big of a security risk to ignore, and so the ability to register with the HS remotely has
+been removed.
+
+It has been replaced by specifying a list of application service registrations in
+``homeserver.yaml``::
+
+  app_service_config_files: ["registration-01.yaml", "registration-02.yaml"]
+  
+Where ``registration-01.yaml`` looks like::
+
+  url: <String>  # e.g. "https://my.application.service.com"
+  as_token: <String>
+  hs_token: <String>
+  sender_localpart: <String>  # This is a new field which denotes the user_id localpart when using the AS token
+  namespaces:
+    users:
+      - exclusive: <Boolean>
+        regex: <String>  # e.g. "@prefix_.*"
+    aliases:
+      - exclusive: <Boolean>
+        regex: <String>
+    rooms:
+      - exclusive: <Boolean>
+        regex: <String>
+
 Upgrading to v0.8.0
 ===================
 
diff --git a/docs/metrics-howto.rst b/docs/metrics-howto.rst
new file mode 100644
index 0000000000..c1f5ae2174
--- /dev/null
+++ b/docs/metrics-howto.rst
@@ -0,0 +1,50 @@
+How to monitor Synapse metrics using Prometheus
+===============================================
+
+1: Install prometheus:
+  Follow instructions at http://prometheus.io/docs/introduction/install/
+
+2: Enable synapse metrics:
+  Simply setting a (local) port number will enable it. Pick a port.
+  prometheus itself defaults to 9090, so starting just above that for
+  locally monitored services seems reasonable. E.g. 9092:
+
+  Add to homeserver.yaml
+
+    metrics_port: 9092
+
+  Restart synapse
+
+3: Check out synapse-prometheus-config
+  https://github.com/matrix-org/synapse-prometheus-config
+
+4: Add ``synapse.html`` and ``synapse.rules``
+  The ``.html`` file needs to appear in prometheus's ``consoles`` directory,
+  and the ``.rules`` file needs to be invoked somewhere in the main config
+  file. A symlink to each from the git checkout into the prometheus directory
+  might be easiest to ensure ``git pull`` keeps it updated.
+
+5: Add a prometheus target for synapse
+  This is easiest if prometheus runs on the same machine as synapse, as it can
+  then just use localhost::
+
+    global: {
+      rule_file: "synapse.rules"
+    }
+
+    job: {
+      name: "synapse"
+
+      target_group: {
+        target: "http://localhost:9092/"
+      }
+    }
+
+6: Start prometheus::
+
+   ./prometheus -config.file=prometheus.conf
+
+7: Wait a few seconds for it to start and perform the first scrape,
+   then visit the console:
+
+    http://server-where-prometheus-runs:9090/consoles/synapse.html
diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index e159e4503f..a21120b313 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -183,18 +183,10 @@ class Auth(object):
         else:
             join_rule = JoinRules.INVITE
 
-        user_level = self._get_power_level_from_event_state(
-            event,
-            event.user_id,
-            auth_events,
-        )
+        user_level = self._get_user_power_level(event.user_id, auth_events)
 
-        ban_level, kick_level, redact_level = (
-            self._get_ops_level_from_event_state(
-                event,
-                auth_events,
-            )
-        )
+        # FIXME (erikj): What should we do here as the default?
+        ban_level = self._get_named_level(auth_events, "ban", 50)
 
         logger.debug(
             "is_membership_change_allowed: %s",
@@ -210,11 +202,6 @@ class Auth(object):
             }
         )
 
-        if ban_level:
-            ban_level = int(ban_level)
-        else:
-            ban_level = 50  # FIXME (erikj): What should we do here?
-
         if Membership.JOIN != membership:
             # JOIN is the only action you can perform if you're not in the room
             if not caller_in_room:  # caller isn't joined
@@ -259,10 +246,7 @@ class Auth(object):
                     403, "You cannot unban user &s." % (target_user_id,)
                 )
             elif target_user_id != event.user_id:
-                if kick_level:
-                    kick_level = int(kick_level)
-                else:
-                    kick_level = 50  # FIXME (erikj): What should we do here?
+                kick_level = self._get_named_level(auth_events, "kick", 50)
 
                 if user_level < kick_level:
                     raise AuthError(
@@ -276,34 +260,42 @@ class Auth(object):
 
         return True
 
-    def _get_power_level_from_event_state(self, event, user_id, auth_events):
+    def _get_power_level_event(self, auth_events):
         key = (EventTypes.PowerLevels, "", )
-        power_level_event = auth_events.get(key)
-        level = None
+        return auth_events.get(key)
+
+    def _get_user_power_level(self, user_id, auth_events):
+        power_level_event = self._get_power_level_event(auth_events)
+
         if power_level_event:
             level = power_level_event.content.get("users", {}).get(user_id)
             if not level:
                 level = power_level_event.content.get("users_default", 0)
+
+            if level is None:
+                return 0
+            else:
+                return int(level)
         else:
             key = (EventTypes.Create, "", )
             create_event = auth_events.get(key)
             if (create_event is not None and
                     create_event.content["creator"] == user_id):
                 return 100
+            else:
+                return 0
 
-        return level
+    def _get_named_level(self, auth_events, name, default):
+        power_level_event = self._get_power_level_event(auth_events)
 
-    def _get_ops_level_from_event_state(self, event, auth_events):
-        key = (EventTypes.PowerLevels, "", )
-        power_level_event = auth_events.get(key)
+        if not power_level_event:
+            return default
 
-        if power_level_event:
-            return (
-                power_level_event.content.get("ban", 50),
-                power_level_event.content.get("kick", 50),
-                power_level_event.content.get("redact", 50),
-            )
-        return None, None, None,
+        level = power_level_event.content.get(name, None)
+        if level is not None:
+            return int(level)
+        else:
+            return default
 
     @defer.inlineCallbacks
     def get_user_by_req(self, request):
@@ -498,16 +490,7 @@ class Auth(object):
         else:
             send_level = 0
 
-        user_level = self._get_power_level_from_event_state(
-            event,
-            event.user_id,
-            auth_events,
-        )
-
-        if user_level:
-            user_level = int(user_level)
-        else:
-            user_level = 0
+        user_level = self._get_user_power_level(event.user_id, auth_events)
 
         if user_level < send_level:
             raise AuthError(
@@ -539,16 +522,9 @@ class Auth(object):
         return True
 
     def _check_redaction(self, event, auth_events):
-        user_level = self._get_power_level_from_event_state(
-            event,
-            event.user_id,
-            auth_events,
-        )
+        user_level = self._get_user_power_level(event.user_id, auth_events)
 
-        _, _, redact_level = self._get_ops_level_from_event_state(
-            event,
-            auth_events,
-        )
+        redact_level = self._get_named_level(auth_events, "redact", 50)
 
         if user_level < redact_level:
             raise AuthError(
@@ -576,11 +552,7 @@ class Auth(object):
         if not current_state:
             return
 
-        user_level = self._get_power_level_from_event_state(
-            event,
-            event.user_id,
-            auth_events,
-        )
+        user_level = self._get_user_power_level(event.user_id, auth_events)
 
         # Check other levels:
         levels_to_check = [
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index eddd889778..72d2bd5b4c 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -35,8 +35,8 @@ class Codes(object):
     LIMIT_EXCEEDED = "M_LIMIT_EXCEEDED"
     CAPTCHA_NEEDED = "M_CAPTCHA_NEEDED"
     CAPTCHA_INVALID = "M_CAPTCHA_INVALID"
-    MISSING_PARAM = "M_MISSING_PARAM",
-    TOO_LARGE = "M_TOO_LARGE",
+    MISSING_PARAM = "M_MISSING_PARAM"
+    TOO_LARGE = "M_TOO_LARGE"
     EXCLUSIVE = "M_EXCLUSIVE"
 
 
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index d5c8f4bf7b..f412a72f59 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -53,6 +53,7 @@ class RegistrationConfig(Config):
 
     @classmethod
     def generate_config(cls, args, config_dir_path):
+        super(RegistrationConfig, cls).generate_config(args, config_dir_path)
         if args.enable_registration is None:
             args.enable_registration = False
 
diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py
index f4db7b8a05..2b4faee4c1 100644
--- a/synapse/crypto/keyring.py
+++ b/synapse/crypto/keyring.py
@@ -24,6 +24,8 @@ from synapse.api.errors import SynapseError, Codes
 
 from synapse.util.retryutils import get_retry_limiter
 
+from synapse.util.async import create_observer
+
 from OpenSSL import crypto
 
 import logging
@@ -38,6 +40,8 @@ class Keyring(object):
         self.clock = hs.get_clock()
         self.hs = hs
 
+        self.key_downloads = {}
+
     @defer.inlineCallbacks
     def verify_json_for_server(self, server_name, json_object):
         logger.debug("Verifying for %s", server_name)
@@ -97,6 +101,22 @@ class Keyring(object):
             defer.returnValue(cached[0])
             return
 
+        download = self.key_downloads.get(server_name)
+
+        if download is None:
+            download = self._get_server_verify_key_impl(server_name, key_ids)
+            self.key_downloads[server_name] = download
+
+            @download.addBoth
+            def callback(ret):
+                del self.key_downloads[server_name]
+                return ret
+
+        r = yield create_observer(download)
+        defer.returnValue(r)
+
+    @defer.inlineCallbacks
+    def _get_server_verify_key_impl(self, server_name, key_ids):
         # Try to fetch the key from the remote server.
 
         limiter = yield get_retry_limiter(
diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index bbc7a0f200..571eacd343 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -36,6 +36,9 @@ metrics = synapse.metrics.get_metrics_for(__name__)
 # Don't bother bumping "last active" time if it differs by less than 60 seconds
 LAST_ACTIVE_GRANULARITY = 60*1000
 
+# Keep no more than this number of offline serial revisions
+MAX_OFFLINE_SERIALS = 1000
+
 
 # TODO(paul): Maybe there's one of these I can steal from somewhere
 def partition(l, func):
@@ -135,6 +138,9 @@ class PresenceHandler(BaseHandler):
         self._remote_sendmap = {}
         # map remote users to sets of local users who're interested in them
         self._remote_recvmap = {}
+        # list of (serial, set of(userids)) tuples, ordered by serial, latest
+        # first
+        self._remote_offline_serials = []
 
         # map any user to a UserPresenceCache
         self._user_cachemap = {}
@@ -714,8 +720,24 @@ class PresenceHandler(BaseHandler):
                 statuscache=statuscache,
             )
 
+            user_id = user.to_string()
+
             if state["presence"] == PresenceState.OFFLINE:
+                self._remote_offline_serials.insert(
+                    0,
+                    (self._user_cachemap_latest_serial, set([user_id]))
+                )
+                while len(self._remote_offline_serials) > MAX_OFFLINE_SERIALS:
+                    self._remote_offline_serials.pop()  # remove the oldest
                 del self._user_cachemap[user]
+            else:
+                # Remove the user from remote_offline_serials now that they're
+                # no longer offline
+                for idx, elem in enumerate(self._remote_offline_serials):
+                    (_, user_ids) = elem
+                    user_ids.discard(user_id)
+                    if not user_ids:
+                        self._remote_offline_serials.pop(idx)
 
         for poll in content.get("poll", []):
             user = UserID.from_string(poll)
@@ -836,6 +858,8 @@ class PresenceEventSource(object):
 
         presence = self.hs.get_handlers().presence_handler
         cachemap = presence._user_cachemap
+        clock = self.clock
+        latest_serial = None
 
         updates = []
         # TODO(paul): use a DeferredList ? How to limit concurrency.
@@ -845,18 +869,31 @@ class PresenceEventSource(object):
             if cached.serial <= from_key:
                 continue
 
-            if (yield self.is_visible(observer_user, observed_user)):
-                updates.append((observed_user, cached))
+            if not (yield self.is_visible(observer_user, observed_user)):
+                continue
+
+            if latest_serial is None or cached.serial > latest_serial:
+                latest_serial = cached.serial
+            updates.append(cached.make_event(user=observed_user, clock=clock))
 
         # TODO(paul): limit
 
-        if updates:
-            clock = self.clock
+        for serial, user_ids in presence._remote_offline_serials:
+            if serial < from_key:
+                break
 
-            latest_serial = max([x[1].serial for x in updates])
-            data = [x[1].make_event(user=x[0], clock=clock) for x in updates]
+            for u in user_ids:
+                updates.append({
+                    "type": "m.presence",
+                    "content": {"user_id": u, "presence": PresenceState.OFFLINE},
+                })
+        # TODO(paul): For the v2 API we want to tell the client their from_key
+        #   is too old if we fell off the end of the _remote_offline_serials
+        #   list, and get them to invalidate+resync. In v1 we have no such
+        #   concept so this is a best-effort result.
 
-            defer.returnValue((data, latest_serial))
+        if updates:
+            defer.returnValue((updates, latest_serial))
         else:
             defer.returnValue(([], presence._user_cachemap_latest_serial))
 
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index bc7f1c2402..a0ee9913bd 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -124,7 +124,7 @@ class RoomCreationHandler(BaseHandler):
         msg_handler = self.hs.get_handlers().message_handler
 
         for event in creation_events:
-            yield msg_handler.create_and_send_event(event)
+            yield msg_handler.create_and_send_event(event, ratelimit=False)
 
         if "name" in config:
             name = config["name"]
@@ -134,7 +134,7 @@ class RoomCreationHandler(BaseHandler):
                 "sender": user_id,
                 "state_key": "",
                 "content": {"name": name},
-            })
+            }, ratelimit=False)
 
         if "topic" in config:
             topic = config["topic"]
@@ -144,7 +144,7 @@ class RoomCreationHandler(BaseHandler):
                 "sender": user_id,
                 "state_key": "",
                 "content": {"topic": topic},
-            })
+            }, ratelimit=False)
 
         for invitee in invite_list:
             yield msg_handler.create_and_send_event({
@@ -153,7 +153,7 @@ class RoomCreationHandler(BaseHandler):
                 "room_id": room_id,
                 "sender": user_id,
                 "content": {"membership": Membership.INVITE},
-            })
+            }, ratelimit=False)
 
         result = {"room_id": room_id}
 
diff --git a/synapse/http/server.py b/synapse/http/server.py
index dee49b9e18..b3706889ab 100644
--- a/synapse/http/server.py
+++ b/synapse/http/server.py
@@ -51,6 +51,80 @@ response_timer = metrics.register_distribution(
     labels=["method", "servlet"]
 )
 
+_next_request_id = 0
+
+
+def request_handler(request_handler):
+    """Wraps a method that acts as a request handler with the necessary logging
+    and exception handling.
+
+    The method must have a signature of "handle_foo(self, request)". The
+    argument "self" must have "version_string" and "clock" attributes. The
+    argument "request" must be a twisted HTTP request.
+
+    The method must return a deferred. If the deferred succeeds we assume that
+    a response has been sent. If the deferred fails with a SynapseError we use
+    it to send a JSON response with the appropriate HTTP reponse code. If the
+    deferred fails with any other type of error we send a 500 reponse.
+
+    We insert a unique request-id into the logging context for this request and
+    log the response and duration for this request.
+    """
+
+    @defer.inlineCallbacks
+    def wrapped_request_handler(self, request):
+        global _next_request_id
+        request_id = "%s-%s" % (request.method, _next_request_id)
+        _next_request_id += 1
+        with LoggingContext(request_id) as request_context:
+            request_context.request = request_id
+            code = None
+            start = self.clock.time_msec()
+            try:
+                logger.info(
+                    "Received request: %s %s",
+                    request.method, request.path
+                )
+                yield request_handler(self, request)
+                code = request.code
+            except CodeMessageException as e:
+                code = e.code
+                if isinstance(e, SynapseError):
+                    logger.info(
+                        "%s SynapseError: %s - %s", request, code, e.msg
+                    )
+                else:
+                    logger.exception(e)
+                outgoing_responses_counter.inc(request.method, str(code))
+                respond_with_json(
+                    request, code, cs_exception(e), send_cors=True,
+                    pretty_print=_request_user_agent_is_curl(request),
+                    version_string=self.version_string,
+                )
+            except:
+                code = 500
+                logger.exception(
+                    "Failed handle request %s.%s on %r: %r",
+                    request_handler.__module__,
+                    request_handler.__name__,
+                    self,
+                    request
+                )
+                respond_with_json(
+                    request,
+                    500,
+                    {"error": "Internal server error"},
+                    send_cors=True
+                )
+            finally:
+                code = str(code) if code else "-"
+                end = self.clock.time_msec()
+                logger.info(
+                    "Processed request: %dms %s %s %s",
+                    end-start, code, request.method, request.path
+                )
+    return wrapped_request_handler
+
 
 class HttpServer(object):
     """ Interface for registering callbacks on a HTTP server
@@ -115,101 +189,55 @@ class JsonResource(HttpServer, resource.Resource):
     def render(self, request):
         """ This get's called by twisted every time someone sends us a request.
         """
-        self._async_render_with_logging_context(request)
+        self._async_render(request)
         return server.NOT_DONE_YET
 
-    _request_id = 0
-
-    @defer.inlineCallbacks
-    def _async_render_with_logging_context(self, request):
-        request_id = "%s-%s" % (request.method, JsonResource._request_id)
-        JsonResource._request_id += 1
-        with LoggingContext(request_id) as request_context:
-            request_context.request = request_id
-            yield self._async_render(request)
-
+    @request_handler
     @defer.inlineCallbacks
     def _async_render(self, request):
         """ This get's called by twisted every time someone sends us a request.
             This checks if anyone has registered a callback for that method and
             path.
         """
-        code = None
         start = self.clock.time_msec()
-        try:
-            # Just say yes to OPTIONS.
-            if request.method == "OPTIONS":
-                self._send_response(request, 200, {})
-                return
-
-            # Loop through all the registered callbacks to check if the method
-            # and path regex match
-            for path_entry in self.path_regexs.get(request.method, []):
-                m = path_entry.pattern.match(request.path)
-                if not m:
-                    continue
-
-                # We found a match! Trigger callback and then return the
-                # returned response. We pass both the request and any
-                # matched groups from the regex to the callback.
-
-                callback = path_entry.callback
-
-                servlet_instance = getattr(callback, "__self__", None)
-                if servlet_instance is not None:
-                    servlet_classname = servlet_instance.__class__.__name__
-                else:
-                    servlet_classname = "%r" % callback
-                incoming_requests_counter.inc(request.method, servlet_classname)
-
-                args = [
-                    urllib.unquote(u).decode("UTF-8") for u in m.groups()
-                ]
-
-                logger.info(
-                    "Received request: %s %s",
-                    request.method, request.path
-                )
+        if request.method == "OPTIONS":
+            self._send_response(request, 200, {})
+            return
+        # Loop through all the registered callbacks to check if the method
+        # and path regex match
+        for path_entry in self.path_regexs.get(request.method, []):
+            m = path_entry.pattern.match(request.path)
+            if not m:
+                continue
+
+            # We found a match! Trigger callback and then return the
+            # returned response. We pass both the request and any
+            # matched groups from the regex to the callback.
+
+            callback = path_entry.callback
+
+            servlet_instance = getattr(callback, "__self__", None)
+            if servlet_instance is not None:
+                servlet_classname = servlet_instance.__class__.__name__
+            else:
+                servlet_classname = "%r" % callback
+            incoming_requests_counter.inc(request.method, servlet_classname)
 
-                code, response = yield callback(request, *args)
+            args = [
+                urllib.unquote(u).decode("UTF-8") for u in m.groups()
+            ]
 
-                self._send_response(request, code, response)
-                response_timer.inc_by(
-                    self.clock.time_msec() - start, request.method, servlet_classname
-                )
+            code, response = yield callback(request, *args)
 
-                return
-
-            # Huh. No one wanted to handle that? Fiiiiiine. Send 400.
-            raise UnrecognizedRequestError()
-        except CodeMessageException as e:
-            if isinstance(e, SynapseError):
-                logger.info("%s SynapseError: %s - %s", request, e.code, e.msg)
-            else:
-                logger.exception(e)
-
-            code = e.code
-            self._send_response(
-                request,
-                code,
-                cs_exception(e),
-                response_code_message=e.response_code_message
-            )
-        except Exception as e:
-            logger.exception(e)
-            self._send_response(
-                request,
-                500,
-                {"error": "Internal server error"}
+            self._send_response(request, code, response)
+            response_timer.inc_by(
+                self.clock.time_msec() - start, request.method, servlet_classname
             )
-        finally:
-            code = str(code) if code else "-"
 
-            end = self.clock.time_msec()
-            logger.info(
-                "Processed request: %dms %s %s %s",
-                end-start, code, request.method, request.path
-            )
+            return
+
+        # Huh. No one wanted to handle that? Fiiiiiine. Send 400.
+        raise UnrecognizedRequestError()
 
     def _send_response(self, request, code, response_json_object,
                        response_code_message=None):
@@ -229,20 +257,10 @@ class JsonResource(HttpServer, resource.Resource):
             request, code, response_json_object,
             send_cors=True,
             response_code_message=response_code_message,
-            pretty_print=self._request_user_agent_is_curl,
+            pretty_print=_request_user_agent_is_curl(request),
             version_string=self.version_string,
         )
 
-    @staticmethod
-    def _request_user_agent_is_curl(request):
-        user_agents = request.requestHeaders.getRawHeaders(
-            "User-Agent", default=[]
-        )
-        for user_agent in user_agents:
-            if "curl" in user_agent:
-                return True
-        return False
-
 
 class RootRedirect(resource.Resource):
     """Redirects the root '/' path to another path."""
@@ -263,8 +281,8 @@ class RootRedirect(resource.Resource):
 def respond_with_json(request, code, json_object, send_cors=False,
                       response_code_message=None, pretty_print=False,
                       version_string=""):
-    if not pretty_print:
-        json_bytes = encode_pretty_printed_json(json_object)
+    if pretty_print:
+        json_bytes = encode_pretty_printed_json(json_object) + "\n"
     else:
         json_bytes = encode_canonical_json(json_object)
 
@@ -304,3 +322,13 @@ def respond_with_json_bytes(request, code, json_bytes, send_cors=False,
     request.write(json_bytes)
     request.finish()
     return NOT_DONE_YET
+
+
+def _request_user_agent_is_curl(request):
+    user_agents = request.requestHeaders.getRawHeaders(
+        "User-Agent", default=[]
+    )
+    for user_agent in user_agents:
+        if "curl" in user_agent:
+            return True
+    return False
diff --git a/synapse/http/servlet.py b/synapse/http/servlet.py
index 265559a3ea..9cda17fcf8 100644
--- a/synapse/http/servlet.py
+++ b/synapse/http/servlet.py
@@ -23,6 +23,61 @@ import logging
 logger = logging.getLogger(__name__)
 
 
+def parse_integer(request, name, default=None, required=False):
+    if name in request.args:
+        try:
+            return int(request.args[name][0])
+        except:
+            message = "Query parameter %r must be an integer" % (name,)
+            raise SynapseError(400, message)
+    else:
+        if required:
+            message = "Missing integer query parameter %r" % (name,)
+            raise SynapseError(400, message)
+        else:
+            return default
+
+
+def parse_boolean(request, name, default=None, required=False):
+    if name in request.args:
+        try:
+            return {
+                "true": True,
+                "false": False,
+            }[request.args[name][0]]
+        except:
+            message = (
+                "Boolean query parameter %r must be one of"
+                " ['true', 'false']"
+            ) % (name,)
+            raise SynapseError(400, message)
+    else:
+        if required:
+            message = "Missing boolean query parameter %r" % (name,)
+            raise SynapseError(400, message)
+        else:
+            return default
+
+
+def parse_string(request, name, default=None, required=False,
+                 allowed_values=None, param_type="string"):
+    if name in request.args:
+        value = request.args[name][0]
+        if allowed_values is not None and value not in allowed_values:
+            message = "Query parameter %r must be one of [%s]" % (
+                name, ", ".join(repr(v) for v in allowed_values)
+            )
+            raise SynapseError(message)
+        else:
+            return value
+    else:
+        if required:
+            message = "Missing %s query parameter %r" % (param_type, name)
+            raise SynapseError(400, message)
+        else:
+            return default
+
+
 class RestServlet(object):
 
     """ A Synapse REST Servlet.
@@ -56,58 +111,3 @@ class RestServlet(object):
                     http_server.register_path(method, pattern, method_handler)
         else:
             raise NotImplementedError("RestServlet must register something.")
-
-    @staticmethod
-    def parse_integer(request, name, default=None, required=False):
-        if name in request.args:
-            try:
-                return int(request.args[name][0])
-            except:
-                message = "Query parameter %r must be an integer" % (name,)
-                raise SynapseError(400, message)
-        else:
-            if required:
-                message = "Missing integer query parameter %r" % (name,)
-                raise SynapseError(400, message)
-            else:
-                return default
-
-    @staticmethod
-    def parse_boolean(request, name, default=None, required=False):
-        if name in request.args:
-            try:
-                return {
-                    "true": True,
-                    "false": False,
-                }[request.args[name][0]]
-            except:
-                message = (
-                    "Boolean query parameter %r must be one of"
-                    " ['true', 'false']"
-                ) % (name,)
-                raise SynapseError(400, message)
-        else:
-            if required:
-                message = "Missing boolean query parameter %r" % (name,)
-                raise SynapseError(400, message)
-            else:
-                return default
-
-    @staticmethod
-    def parse_string(request, name, default=None, required=False,
-                     allowed_values=None, param_type="string"):
-        if name in request.args:
-            value = request.args[name][0]
-            if allowed_values is not None and value not in allowed_values:
-                message = "Query parameter %r must be one of [%s]" % (
-                    name, ", ".join(repr(v) for v in allowed_values)
-                )
-                raise SynapseError(message)
-            else:
-                return value
-        else:
-            if required:
-                message = "Missing %s query parameter %r" % (param_type, name)
-                raise SynapseError(400, message)
-            else:
-                return default
diff --git a/synapse/push/baserules.py b/synapse/push/baserules.py
index 60fd35fbfb..f3d1cf5c5f 100644
--- a/synapse/push/baserules.py
+++ b/synapse/push/baserules.py
@@ -1,3 +1,17 @@
+# Copyright 2015 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 from synapse.push.rulekinds import PRIORITY_CLASS_MAP, PRIORITY_CLASS_INVERSE_MAP
 
 
@@ -112,7 +126,25 @@ def make_base_prepend_override_rules():
 def make_base_append_override_rules():
     return [
         {
-            'rule_id': 'global/override/.m.rule.call',
+            'rule_id': 'global/override/.m.rule.suppress_notices',
+            'conditions': [
+                {
+                    'kind': 'event_match',
+                    'key': 'content.msgtype',
+                    'pattern': 'm.notice',
+                }
+            ],
+            'actions': [
+                'dont_notify',
+            ]
+        }
+    ]
+
+
+def make_base_append_underride_rules(user):
+    return [
+        {
+            'rule_id': 'global/underride/.m.rule.call',
             'conditions': [
                 {
                     'kind': 'event_match',
@@ -132,19 +164,6 @@ def make_base_append_override_rules():
             ]
         },
         {
-            'rule_id': 'global/override/.m.rule.suppress_notices',
-            'conditions': [
-                {
-                    'kind': 'event_match',
-                    'key': 'content.msgtype',
-                    'pattern': 'm.notice',
-                }
-            ],
-            'actions': [
-                'dont_notify',
-            ]
-        },
-        {
             'rule_id': 'global/override/.m.rule.contains_display_name',
             'conditions': [
                 {
@@ -162,7 +181,7 @@ def make_base_append_override_rules():
             ]
         },
         {
-            'rule_id': 'global/override/.m.rule.room_one_to_one',
+            'rule_id': 'global/underride/.m.rule.room_one_to_one',
             'conditions': [
                 {
                     'kind': 'room_member_count',
@@ -179,12 +198,7 @@ def make_base_append_override_rules():
                     'value': False
                 }
             ]
-        }
-    ]
-
-
-def make_base_append_underride_rules(user):
-    return [
+        },
         {
             'rule_id': 'global/underride/.m.rule.invite_for_me',
             'conditions': [
diff --git a/synapse/push/rulekinds.py b/synapse/push/rulekinds.py
index 660aa4e10e..4c591aa638 100644
--- a/synapse/push/rulekinds.py
+++ b/synapse/push/rulekinds.py
@@ -1,3 +1,17 @@
+# Copyright 2015 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 PRIORITY_CLASS_MAP = {
     'underride': 1,
     'sender': 2,
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index dac927d0a7..8b457419cf 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -1,10 +1,24 @@
+# Copyright 2015 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import logging
 from distutils.version import LooseVersion
 
 logger = logging.getLogger(__name__)
 
 REQUIREMENTS = {
-    "syutil>=0.0.4": ["syutil"],
+    "syutil>=0.0.5": ["syutil"],
     "Twisted==14.0.2": ["twisted==14.0.2"],
     "service_identity>=1.0.0": ["service_identity>=1.0.0"],
     "pyopenssl>=0.14": ["OpenSSL>=0.14"],
@@ -43,8 +57,8 @@ DEPENDENCY_LINKS = [
     ),
     github_link(
         project="matrix-org/syutil",
-        version="v0.0.4",
-        egg="syutil-0.0.4",
+        version="v0.0.5",
+        egg="syutil-0.0.5",
     ),
     github_link(
         project="matrix-org/matrix-angular-sdk",
diff --git a/synapse/rest/client/v2_alpha/sync.py b/synapse/rest/client/v2_alpha/sync.py
index 3056ec45cf..f2fd0b9f32 100644
--- a/synapse/rest/client/v2_alpha/sync.py
+++ b/synapse/rest/client/v2_alpha/sync.py
@@ -15,7 +15,9 @@
 
 from twisted.internet import defer
 
-from synapse.http.servlet import RestServlet
+from synapse.http.servlet import (
+    RestServlet, parse_string, parse_integer, parse_boolean
+)
 from synapse.handlers.sync import SyncConfig
 from synapse.types import StreamToken
 from synapse.events.utils import (
@@ -87,20 +89,20 @@ class SyncRestServlet(RestServlet):
     def on_GET(self, request):
         user, client = yield self.auth.get_user_by_req(request)
 
-        timeout = self.parse_integer(request, "timeout", default=0)
-        limit = self.parse_integer(request, "limit", required=True)
-        gap = self.parse_boolean(request, "gap", default=True)
-        sort = self.parse_string(
+        timeout = parse_integer(request, "timeout", default=0)
+        limit = parse_integer(request, "limit", required=True)
+        gap = parse_boolean(request, "gap", default=True)
+        sort = parse_string(
             request, "sort", default="timeline,asc",
             allowed_values=self.ALLOWED_SORT
         )
-        since = self.parse_string(request, "since")
-        set_presence = self.parse_string(
+        since = parse_string(request, "since")
+        set_presence = parse_string(
             request, "set_presence", default="online",
             allowed_values=self.ALLOWED_PRESENCE
         )
-        backfill = self.parse_boolean(request, "backfill", default=False)
-        filter_id = self.parse_string(request, "filter", default=None)
+        backfill = parse_boolean(request, "backfill", default=False)
+        filter_id = parse_string(request, "filter", default=None)
 
         logger.info(
             "/sync: user=%r, timeout=%r, limit=%r, gap=%r, sort=%r, since=%r,"
diff --git a/synapse/rest/media/v1/base_resource.py b/synapse/rest/media/v1/base_resource.py
index b10cbddb81..08c8d75af4 100644
--- a/synapse/rest/media/v1/base_resource.py
+++ b/synapse/rest/media/v1/base_resource.py
@@ -18,13 +18,15 @@ from .thumbnailer import Thumbnailer
 from synapse.http.server import respond_with_json
 from synapse.util.stringutils import random_string
 from synapse.api.errors import (
-    cs_exception, CodeMessageException, cs_error, Codes, SynapseError
+    cs_error, Codes, SynapseError
 )
 
 from twisted.internet import defer
 from twisted.web.resource import Resource
 from twisted.protocols.basic import FileSender
 
+from synapse.util.async import create_observer
+
 import os
 
 import logging
@@ -32,6 +34,18 @@ import logging
 logger = logging.getLogger(__name__)
 
 
+def parse_media_id(request):
+    try:
+        server_name, media_id = request.postpath
+        return (server_name, media_id)
+    except:
+        raise SynapseError(
+            404,
+            "Invalid media id token %r" % (request.postpath,),
+            Codes.UNKNOWN,
+        )
+
+
 class BaseMediaResource(Resource):
     isLeaf = True
 
@@ -45,74 +59,9 @@ class BaseMediaResource(Resource):
         self.max_upload_size = hs.config.max_upload_size
         self.max_image_pixels = hs.config.max_image_pixels
         self.filepaths = filepaths
+        self.version_string = hs.version_string
         self.downloads = {}
 
-    @staticmethod
-    def catch_errors(request_handler):
-        @defer.inlineCallbacks
-        def wrapped_request_handler(self, request):
-            try:
-                yield request_handler(self, request)
-            except CodeMessageException as e:
-                logger.info("Responding with error: %r", e)
-                respond_with_json(
-                    request, e.code, cs_exception(e), send_cors=True
-                )
-            except:
-                logger.exception(
-                    "Failed handle request %s.%s on %r",
-                    request_handler.__module__,
-                    request_handler.__name__,
-                    self,
-                )
-                respond_with_json(
-                    request,
-                    500,
-                    {"error": "Internal server error"},
-                    send_cors=True
-                )
-        return wrapped_request_handler
-
-    @staticmethod
-    def _parse_media_id(request):
-        try:
-            server_name, media_id = request.postpath
-            return (server_name, media_id)
-        except:
-            raise SynapseError(
-                404,
-                "Invalid media id token %r" % (request.postpath,),
-                Codes.UNKNOWN,
-            )
-
-    @staticmethod
-    def _parse_integer(request, arg_name, default=None):
-        try:
-            if default is None:
-                return int(request.args[arg_name][0])
-            else:
-                return int(request.args.get(arg_name, [default])[0])
-        except:
-            raise SynapseError(
-                400,
-                "Missing integer argument %r" % (arg_name,),
-                Codes.UNKNOWN,
-            )
-
-    @staticmethod
-    def _parse_string(request, arg_name, default=None):
-        try:
-            if default is None:
-                return request.args[arg_name][0]
-            else:
-                return request.args.get(arg_name, [default])[0]
-        except:
-            raise SynapseError(
-                400,
-                "Missing string argument %r" % (arg_name,),
-                Codes.UNKNOWN,
-            )
-
     def _respond_404(self, request):
         respond_with_json(
             request, 404,
@@ -140,7 +89,7 @@ class BaseMediaResource(Resource):
             def callback(media_info):
                 del self.downloads[key]
                 return media_info
-        return download
+        return create_observer(download)
 
     @defer.inlineCallbacks
     def _get_remote_media_impl(self, server_name, media_id):
diff --git a/synapse/rest/media/v1/download_resource.py b/synapse/rest/media/v1/download_resource.py
index c585bb11f7..0fe6abf647 100644
--- a/synapse/rest/media/v1/download_resource.py
+++ b/synapse/rest/media/v1/download_resource.py
@@ -13,7 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from .base_resource import BaseMediaResource
+from .base_resource import BaseMediaResource, parse_media_id
+from synapse.http.server import request_handler
 
 from twisted.web.server import NOT_DONE_YET
 from twisted.internet import defer
@@ -28,15 +29,10 @@ class DownloadResource(BaseMediaResource):
         self._async_render_GET(request)
         return NOT_DONE_YET
 
-    @BaseMediaResource.catch_errors
+    @request_handler
     @defer.inlineCallbacks
     def _async_render_GET(self, request):
-        try:
-            server_name, media_id = request.postpath
-        except:
-            self._respond_404(request)
-            return
-
+        server_name, media_id = parse_media_id(request)
         if server_name == self.server_name:
             yield self._respond_local_file(request, media_id)
         else:
diff --git a/synapse/rest/media/v1/identicon_resource.py b/synapse/rest/media/v1/identicon_resource.py
index 912856386a..603859d5d4 100644
--- a/synapse/rest/media/v1/identicon_resource.py
+++ b/synapse/rest/media/v1/identicon_resource.py
@@ -1,3 +1,17 @@
+# Copyright 2015 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 from pydenticon import Generator
 from twisted.web.resource import Resource
 
diff --git a/synapse/rest/media/v1/thumbnail_resource.py b/synapse/rest/media/v1/thumbnail_resource.py
index 84f5e3463c..1dadd880b2 100644
--- a/synapse/rest/media/v1/thumbnail_resource.py
+++ b/synapse/rest/media/v1/thumbnail_resource.py
@@ -14,7 +14,9 @@
 # limitations under the License.
 
 
-from .base_resource import BaseMediaResource
+from .base_resource import BaseMediaResource, parse_media_id
+from synapse.http.servlet import parse_string, parse_integer
+from synapse.http.server import request_handler
 
 from twisted.web.server import NOT_DONE_YET
 from twisted.internet import defer
@@ -31,14 +33,14 @@ class ThumbnailResource(BaseMediaResource):
         self._async_render_GET(request)
         return NOT_DONE_YET
 
-    @BaseMediaResource.catch_errors
+    @request_handler
     @defer.inlineCallbacks
     def _async_render_GET(self, request):
-        server_name, media_id = self._parse_media_id(request)
-        width = self._parse_integer(request, "width")
-        height = self._parse_integer(request, "height")
-        method = self._parse_string(request, "method", "scale")
-        m_type = self._parse_string(request, "type", "image/png")
+        server_name, media_id = parse_media_id(request)
+        width = parse_integer(request, "width")
+        height = parse_integer(request, "height")
+        method = parse_string(request, "method", "scale")
+        m_type = parse_string(request, "type", "image/png")
 
         if server_name == self.server_name:
             yield self._respond_local_thumbnail(
diff --git a/synapse/rest/media/v1/upload_resource.py b/synapse/rest/media/v1/upload_resource.py
index e5aba3af4c..cc571976a5 100644
--- a/synapse/rest/media/v1/upload_resource.py
+++ b/synapse/rest/media/v1/upload_resource.py
@@ -13,12 +13,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.http.server import respond_with_json
+from synapse.http.server import respond_with_json, request_handler
 
 from synapse.util.stringutils import random_string
-from synapse.api.errors import (
-    cs_exception, SynapseError, CodeMessageException
-)
+from synapse.api.errors import SynapseError
 
 from twisted.web.server import NOT_DONE_YET
 from twisted.internet import defer
@@ -69,53 +67,42 @@ class UploadResource(BaseMediaResource):
 
         defer.returnValue("mxc://%s/%s" % (self.server_name, media_id))
 
+    @request_handler
     @defer.inlineCallbacks
     def _async_render_POST(self, request):
-        try:
-            auth_user, client = yield self.auth.get_user_by_req(request)
-            # TODO: The checks here are a bit late. The content will have
-            # already been uploaded to a tmp file at this point
-            content_length = request.getHeader("Content-Length")
-            if content_length is None:
-                raise SynapseError(
-                    msg="Request must specify a Content-Length", code=400
-                )
-            if int(content_length) > self.max_upload_size:
-                raise SynapseError(
-                    msg="Upload request body is too large",
-                    code=413,
-                )
-
-            headers = request.requestHeaders
-
-            if headers.hasHeader("Content-Type"):
-                media_type = headers.getRawHeaders("Content-Type")[0]
-            else:
-                raise SynapseError(
-                    msg="Upload request missing 'Content-Type'",
-                    code=400,
-                )
-
-            # if headers.hasHeader("Content-Disposition"):
-            #     disposition = headers.getRawHeaders("Content-Disposition")[0]
-            # TODO(markjh): parse content-dispostion
-
-            content_uri = yield self.create_content(
-                media_type, None, request.content.read(),
-                content_length, auth_user
+        auth_user, client = yield self.auth.get_user_by_req(request)
+        # TODO: The checks here are a bit late. The content will have
+        # already been uploaded to a tmp file at this point
+        content_length = request.getHeader("Content-Length")
+        if content_length is None:
+            raise SynapseError(
+                msg="Request must specify a Content-Length", code=400
             )
-
-            respond_with_json(
-                request, 200, {"content_uri": content_uri}, send_cors=True
+        if int(content_length) > self.max_upload_size:
+            raise SynapseError(
+                msg="Upload request body is too large",
+                code=413,
             )
-        except CodeMessageException as e:
-            logger.exception(e)
-            respond_with_json(request, e.code, cs_exception(e), send_cors=True)
-        except:
-            logger.exception("Failed to store file")
-            respond_with_json(
-                request,
-                500,
-                {"error": "Internal server error"},
-                send_cors=True
+
+        headers = request.requestHeaders
+
+        if headers.hasHeader("Content-Type"):
+            media_type = headers.getRawHeaders("Content-Type")[0]
+        else:
+            raise SynapseError(
+                msg="Upload request missing 'Content-Type'",
+                code=400,
             )
+
+        # if headers.hasHeader("Content-Disposition"):
+        #     disposition = headers.getRawHeaders("Content-Disposition")[0]
+        # TODO(markjh): parse content-dispostion
+
+        content_uri = yield self.create_content(
+            media_type, None, request.content.read(),
+            content_length, auth_user
+        )
+
+        respond_with_json(
+            request, 200, {"content_uri": content_uri}, send_cors=True
+        )
diff --git a/synapse/storage/schema/delta/14/upgrade_appservice_db.py b/synapse/storage/schema/delta/14/upgrade_appservice_db.py
index 847b1c5b89..9f3a4dd4c5 100644
--- a/synapse/storage/schema/delta/14/upgrade_appservice_db.py
+++ b/synapse/storage/schema/delta/14/upgrade_appservice_db.py
@@ -1,3 +1,17 @@
+# Copyright 2015 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import json
 import logging
 
diff --git a/synapse/storage/schema/delta/14/v14.sql b/synapse/storage/schema/delta/14/v14.sql
index 8c47d4b0f4..e5fedc5851 100644
--- a/synapse/storage/schema/delta/14/v14.sql
+++ b/synapse/storage/schema/delta/14/v14.sql
@@ -1,3 +1,17 @@
+/* Copyright 2015 OpenMarket Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 CREATE TABLE IF NOT EXISTS push_rules_enable (
   id INTEGER PRIMARY KEY AUTOINCREMENT,
   user_name VARCHAR(150) NOT NULL,
diff --git a/synapse/util/async.py b/synapse/util/async.py
index c4fe5d522f..d8febdb90c 100644
--- a/synapse/util/async.py
+++ b/synapse/util/async.py
@@ -32,3 +32,22 @@ def run_on_reactor():
     iteration of the main loop
     """
     return sleep(0)
+
+
+def create_observer(deferred):
+    """Creates a deferred that observes the result or failure of the given
+     deferred *without* affecting the given deferred.
+    """
+    d = defer.Deferred()
+
+    def callback(r):
+        d.callback(r)
+        return r
+
+    def errback(f):
+        d.errback(f)
+        return f
+
+    deferred.addCallbacks(callback, errback)
+
+    return d
diff --git a/tests/handlers/test_presence.py b/tests/handlers/test_presence.py
index 9b0e606918..70147b017e 100644
--- a/tests/handlers/test_presence.py
+++ b/tests/handlers/test_presence.py
@@ -884,6 +884,71 @@ class PresencePushTestCase(MockedDatastorePresenceTestCase):
         )
 
     @defer.inlineCallbacks
+    def test_recv_remote_offline(self):
+        """ Various tests relating to SYN-261 """
+        potato_set = self.handler._remote_recvmap.setdefault(self.u_potato,
+                set())
+        potato_set.add(self.u_apple)
+
+        self.room_members = [self.u_banana, self.u_potato]
+
+        self.assertEquals(self.event_source.get_current_key(), 0)
+
+        yield self.mock_federation_resource.trigger("PUT",
+            "/_matrix/federation/v1/send/1000000/",
+            _make_edu_json("elsewhere", "m.presence",
+                content={
+                    "push": [
+                        {"user_id": "@potato:remote",
+                         "presence": "offline"},
+                    ],
+                }
+            )
+        )
+
+        self.assertEquals(self.event_source.get_current_key(), 1)
+
+        (events, _) = yield self.event_source.get_new_events_for_user(
+            self.u_apple, 0, None
+        )
+        self.assertEquals(events,
+            [
+                {"type": "m.presence",
+                 "content": {
+                     "user_id": "@potato:remote",
+                     "presence": OFFLINE,
+                }}
+            ]
+        )
+
+        yield self.mock_federation_resource.trigger("PUT",
+            "/_matrix/federation/v1/send/1000001/",
+            _make_edu_json("elsewhere", "m.presence",
+                content={
+                    "push": [
+                        {"user_id": "@potato:remote",
+                         "presence": "online"},
+                    ],
+                }
+            )
+        )
+
+        self.assertEquals(self.event_source.get_current_key(), 2)
+
+        (events, _) = yield self.event_source.get_new_events_for_user(
+            self.u_apple, 0, None
+        )
+        self.assertEquals(events,
+            [
+                {"type": "m.presence",
+                 "content": {
+                     "user_id": "@potato:remote",
+                     "presence": ONLINE,
+                }}
+            ]
+        )
+
+    @defer.inlineCallbacks
     def test_join_room_local(self):
         self.room_members = [self.u_apple, self.u_banana]