From df3a661e4adb7676682a5e3c298a2dfda18b08a1 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Fri, 18 Jan 2019 10:04:47 +0000
Subject: [PATCH 01/11] Search for messages across predecessor rooms

Signed-off-by: Andrew Morgan <andrew@amorgan.xyz>
---
 synapse/api/filtering.py   |  3 ++
 synapse/handlers/search.py | 69 ++++++++++++++++++++++++++++++++++++++
 synapse/storage/state.py   |  1 +
 3 files changed, 73 insertions(+)

diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py
index 16ad654864..84000e6422 100644
--- a/synapse/api/filtering.py
+++ b/synapse/api/filtering.py
@@ -444,6 +444,9 @@ class Filter(object):
     def include_redundant_members(self):
         return self.filter_json.get("include_redundant_members", False)
 
+    def add_room_ids(self, room_ids):
+        self.rooms += room_ids
+
 
 def _matches_wildcard(actual_value, filter_value):
     if filter_value.endswith("*"):
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index ec936bbb4e..77e7e4e0fb 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -37,6 +37,54 @@ class SearchHandler(BaseHandler):
     def __init__(self, hs):
         super(SearchHandler, self).__init__(hs)
 
+    @defer.inlineCallbacks
+    def get_old_rooms_from_upgraded_room(self, room_id):
+        """Retrieves room IDs of old rooms in the history of an upgraded room.
+
+        We do so by checking the m.room.create event of the room for a
+        `predecessor` key. If it exists, we add the room ID to our return
+        list and then check that room for a m.room.create event and so on
+        until we can no longer find any more previous rooms.
+
+        The full list of all found rooms in then returned.
+
+        Args:
+            room_id (str): The ID of the room to search through.
+
+        Returns:
+            dict of past room IDs as strings
+        """
+
+        historical_room_ids = []
+
+        while True:
+            state_ids = yield self.store.get_current_state_ids(room_id)
+            create_id = state_ids.get((EventTypes.Create, ""))
+
+            # If we can't find the create event, assume we've hit a dead end
+            if not create_id:
+                break
+
+            # Retrieve the room's create event
+            create_event = yield self.store.get_event(create_id)
+
+            if not create_event:
+                break
+
+            # Check if a predecessor room is present
+            predecessor = create_event.content.get("predecessor", None)
+            if not predecessor:
+                break
+
+            # Add predecessor's room ID
+            historical_room_id = predecessor["room_id"]
+            historical_room_ids.append(historical_room_id)
+
+            # Scan through the old room for further predecessors
+            room_id = historical_room_id
+
+        defer.returnValue(historical_room_ids)
+
     @defer.inlineCallbacks
     def search(self, user, content, batch=None):
         """Performs a full text search for a user.
@@ -139,6 +187,27 @@ class SearchHandler(BaseHandler):
 
         room_ids = search_filter.filter_rooms(room_ids)
 
+        # If doing a subset of all rooms seearch, check if any of the rooms
+        # are from an upgraded room, and search their contents as well
+        # XXX: There is the possibility that we don't have a create event for
+        # the room in question, in which case we can't return all the results
+        # we want to.
+        # Ideally we would just return the results we can get now, and
+        # try to get more results from other servers in the background.
+        if search_filter.rooms:
+            historical_room_ids = []
+            for room_id in room_ids:
+                # Add any previous rooms to the search if they exist
+                ids = yield self.get_old_rooms_from_upgraded_room(room_id)
+                historical_room_ids += ids
+
+            # Add any found rooms to the list to search
+            for historical_room_id in historical_room_ids:
+                room_ids.add(historical_room_id)
+
+            # Prevent any historical events from being filtered
+            search_filter.add_room_ids(historical_room_ids)
+
         if batch_group == "room_id":
             room_ids.intersection_update({batch_group_key})
 
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index a134e9b3e8..49b3ff4a71 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -448,6 +448,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         Returns:
             deferred: dict of (type, state_key) -> event_id
         """
+
         def _get_current_state_ids_txn(txn):
             txn.execute(
                 """SELECT type, state_key, event_id FROM current_state_events

From cb80db894186c4c9a4991e0623530a038eb82543 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Fri, 18 Jan 2019 11:22:00 +0000
Subject: [PATCH 02/11] Add changelog

---
 changelog.d/4415.feature | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/4415.feature

diff --git a/changelog.d/4415.feature b/changelog.d/4415.feature
new file mode 100644
index 0000000000..1fb1d58f8f
--- /dev/null
+++ b/changelog.d/4415.feature
@@ -0,0 +1 @@
+Search now includes results from predecessor rooms after a room upgrade.
\ No newline at end of file

From c9bfb058d85f6205fada062c78a4d1eca119417c Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 22 Jan 2019 11:12:48 +0000
Subject: [PATCH 03/11] Fix a bug with single-room search searching all rooms

* Create a new method for getting predecessor rooms
* Remove formatting change
---
 synapse/api/filtering.py   | 15 ++++++++++++--
 synapse/handlers/search.py | 42 +++++++++-----------------------------
 synapse/storage/state.py   | 29 +++++++++++++++++++++++++-
 3 files changed, 51 insertions(+), 35 deletions(-)

diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py
index 84000e6422..0d8957175d 100644
--- a/synapse/api/filtering.py
+++ b/synapse/api/filtering.py
@@ -444,8 +444,19 @@ class Filter(object):
     def include_redundant_members(self):
         return self.filter_json.get("include_redundant_members", False)
 
-    def add_room_ids(self, room_ids):
-        self.rooms += room_ids
+    def with_room_ids(self, room_ids):
+        """Returns a new filter with the given room IDs appended.
+
+        Args:
+            room_ids (list): A list of room_ids.
+
+        Returns:
+            filter: A new filter including the given rooms and the old
+                    filter's rooms.
+        """
+        newFilter = self
+        newFilter.rooms += room_ids
+        return newFilter
 
 
 def _matches_wildcard(actual_value, filter_value):
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index 77e7e4e0fb..75c26fe065 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -49,39 +49,26 @@ class SearchHandler(BaseHandler):
         The full list of all found rooms in then returned.
 
         Args:
-            room_id (str): The ID of the room to search through.
+            room_id (str): id of the room to search through.
 
         Returns:
-            dict of past room IDs as strings
+            Deferred[iterable[str]]: predecessor room ids
         """
 
         historical_room_ids = []
 
         while True:
-            state_ids = yield self.store.get_current_state_ids(room_id)
-            create_id = state_ids.get((EventTypes.Create, ""))
+            predecessor = yield self.store.get_room_predecessor(room_id)
 
-            # If we can't find the create event, assume we've hit a dead end
-            if not create_id:
-                break
-
-            # Retrieve the room's create event
-            create_event = yield self.store.get_event(create_id)
-
-            if not create_event:
-                break
-
-            # Check if a predecessor room is present
-            predecessor = create_event.content.get("predecessor", None)
+            # If no predecessor, assume we've hit a dead end
             if not predecessor:
                 break
 
             # Add predecessor's room ID
-            historical_room_id = predecessor["room_id"]
-            historical_room_ids.append(historical_room_id)
+            historical_room_ids.append(predecessor["room_id"])
 
             # Scan through the old room for further predecessors
-            room_id = historical_room_id
+            room_id = predecessor["room_id"]
 
         defer.returnValue(historical_room_ids)
 
@@ -185,28 +172,19 @@ class SearchHandler(BaseHandler):
         )
         room_ids = set(r.room_id for r in rooms)
 
-        room_ids = search_filter.filter_rooms(room_ids)
-
         # If doing a subset of all rooms seearch, check if any of the rooms
         # are from an upgraded room, and search their contents as well
-        # XXX: There is the possibility that we don't have a create event for
-        # the room in question, in which case we can't return all the results
-        # we want to.
-        # Ideally we would just return the results we can get now, and
-        # try to get more results from other servers in the background.
         if search_filter.rooms:
             historical_room_ids = []
-            for room_id in room_ids:
+            for room_id in search_filter.rooms:
                 # Add any previous rooms to the search if they exist
                 ids = yield self.get_old_rooms_from_upgraded_room(room_id)
                 historical_room_ids += ids
 
-            # Add any found rooms to the list to search
-            for historical_room_id in historical_room_ids:
-                room_ids.add(historical_room_id)
-
             # Prevent any historical events from being filtered
-            search_filter.add_room_ids(historical_room_ids)
+            search_filter = search_filter.with_room_ids(historical_room_ids)
+
+        room_ids = search_filter.filter_rooms(room_ids)
 
         if batch_group == "room_id":
             room_ids.intersection_update({batch_group_key})
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 49b3ff4a71..b064671851 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -437,6 +437,34 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         create_event = yield self.get_event(create_id)
         defer.returnValue(create_event.content.get("room_version", "1"))
 
+    @defer.inlineCallbacks
+    def get_room_predecessor(self, room_id):
+        """Get the predecessor room of an upgraded room if one exists.
+        Otherwise return None.
+
+        Args:
+            room_id (str)
+
+        Returns:
+            Deferred[str]: predecessor room id
+        """
+
+        state_ids = yield self.get_current_state_ids(room_id)
+        create_id = state_ids.get((EventTypes.Create, ""))
+
+        # If we can't find the create event, assume we've hit a dead end
+        if not create_id:
+            return None
+
+        # Retrieve the room's create event
+        create_event = yield self.get_event(create_id)
+
+        if not create_event:
+            return None
+
+        # Return predecessor if present
+        return create_event.content.get("predecessor", None)
+
     @cached(max_entries=100000, iterable=True)
     def get_current_state_ids(self, room_id):
         """Get the current state event ids for a room based on the
@@ -448,7 +476,6 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         Returns:
             deferred: dict of (type, state_key) -> event_id
         """
-
         def _get_current_state_ids_txn(txn):
             txn.execute(
                 """SELECT type, state_key, event_id FROM current_state_events

From c433f6109145f0cf6c80dd07ee118b68a3a0cd4e Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 22 Jan 2019 12:06:36 +0000
Subject: [PATCH 04/11] Ensure new filter is actually created

---
 synapse/api/filtering.py | 2 +-
 synapse/storage/state.py | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py
index 0d8957175d..f3a056110f 100644
--- a/synapse/api/filtering.py
+++ b/synapse/api/filtering.py
@@ -454,7 +454,7 @@ class Filter(object):
             filter: A new filter including the given rooms and the old
                     filter's rooms.
         """
-        newFilter = self
+        newFilter = Filter(self.filter_json)
         newFilter.rooms += room_ids
         return newFilter
 
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index b064671851..981d1e3600 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -448,7 +448,6 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         Returns:
             Deferred[str]: predecessor room id
         """
-
         state_ids = yield self.get_current_state_ids(room_id)
         create_id = state_ids.get((EventTypes.Create, ""))
 

From 277e50462d1422ac8cfe2df7cd2213288f3d14c5 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 22 Jan 2019 12:40:26 +0000
Subject: [PATCH 05/11] Do not return in a deferred function

---
 synapse/storage/state.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 981d1e3600..fceb9744aa 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -453,16 +453,16 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
 
         # If we can't find the create event, assume we've hit a dead end
         if not create_id:
-            return None
+            defer.returnValue(None)
 
         # Retrieve the room's create event
         create_event = yield self.get_event(create_id)
 
         if not create_event:
-            return None
+            defer.returnValue(None)
 
         # Return predecessor if present
-        return create_event.content.get("predecessor", None)
+        defer.returnValue(create_event.content.get("predecessor", None))
 
     @cached(max_entries=100000, iterable=True)
     def get_current_state_ids(self, room_id):

From 8ea509a9357d53f71e7bef09aae59f53b9f2317e Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Thu, 24 Jan 2019 17:21:35 +0000
Subject: [PATCH 06/11] Update synapse/api/filtering.py

Co-Authored-By: anoadragon453 <1342360+anoadragon453@users.noreply.github.com>
---
 synapse/api/filtering.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py
index f3a056110f..3906475403 100644
--- a/synapse/api/filtering.py
+++ b/synapse/api/filtering.py
@@ -448,7 +448,7 @@ class Filter(object):
         """Returns a new filter with the given room IDs appended.
 
         Args:
-            room_ids (list): A list of room_ids.
+            room_ids (iterable[unicode]): The room_ids to add
 
         Returns:
             filter: A new filter including the given rooms and the old

From 03c85335d1d386c0523af3b6bf992f83bfb905d7 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Thu, 24 Jan 2019 17:22:09 +0000
Subject: [PATCH 07/11] Apply suggestions from code review

Co-Authored-By: anoadragon453 <1342360+anoadragon453@users.noreply.github.com>
---
 synapse/handlers/search.py | 2 +-
 synapse/storage/state.py   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index 75c26fe065..49c439313e 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -52,7 +52,7 @@ class SearchHandler(BaseHandler):
             room_id (str): id of the room to search through.
 
         Returns:
-            Deferred[iterable[str]]: predecessor room ids
+            Deferred[iterable[unicode]]: predecessor room ids
         """
 
         historical_room_ids = []
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index fceb9744aa..0a0691cd00 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -446,7 +446,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
             room_id (str)
 
         Returns:
-            Deferred[str]: predecessor room id
+            Deferred[unicode|None]: predecessor room id
         """
         state_ids = yield self.get_current_state_ids(room_id)
         create_id = state_ids.get((EventTypes.Create, ""))

From e1781b043b4a73e1b22142b6e09c07ddd782ae57 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Thu, 24 Jan 2019 17:23:39 +0000
Subject: [PATCH 08/11] Remove redundant create event None check

---
 synapse/storage/state.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index fceb9744aa..c02130d9d6 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -458,9 +458,6 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         # Retrieve the room's create event
         create_event = yield self.get_event(create_id)
 
-        if not create_event:
-            defer.returnValue(None)
-
         # Return predecessor if present
         defer.returnValue(create_event.content.get("predecessor", None))
 

From 0b3fd1401fdebb944729cf46d6de9c3bff482933 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>
Date: Fri, 25 Jan 2019 11:25:02 +0000
Subject: [PATCH 09/11] Don't require sqlite3 when using postgres (#4466)

---
 changelog.d/4466.misc             | 1 +
 synapse/storage/engines/sqlite.py | 3 +--
 2 files changed, 2 insertions(+), 2 deletions(-)
 create mode 100644 changelog.d/4466.misc

diff --git a/changelog.d/4466.misc b/changelog.d/4466.misc
new file mode 100644
index 0000000000..58130b6190
--- /dev/null
+++ b/changelog.d/4466.misc
@@ -0,0 +1 @@
+Synapse will now take advantage of native UPSERT functionality in PostgreSQL 9.5+ and SQLite 3.24+.
diff --git a/synapse/storage/engines/sqlite.py b/synapse/storage/engines/sqlite.py
index c64d73ff21..059ab81055 100644
--- a/synapse/storage/engines/sqlite.py
+++ b/synapse/storage/engines/sqlite.py
@@ -15,7 +15,6 @@
 
 import struct
 import threading
-from sqlite3 import sqlite_version_info
 
 from synapse.storage.prepare_database import prepare_database
 
@@ -37,7 +36,7 @@ class Sqlite3Engine(object):
         Do we support native UPSERTs? This requires SQLite3 3.24+, plus some
         more work we haven't done yet to tell what was inserted vs updated.
         """
-        return sqlite_version_info >= (3, 24, 0)
+        return self.module.sqlite_version_info >= (3, 24, 0)
 
     def check_database(self, txn):
         pass

From 8520bc3109c2de6175391497941f3fc0b74c08e5 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Fri, 25 Jan 2019 12:38:16 +0000
Subject: [PATCH 10/11] Fix Host header sent by MatrixFederationAgent (#4468)

Move the Host header logic down here so that (a) it is used if we reuse the
agent elsewhere, and (b) we can mess about with it with .well-known.
---
 changelog.d/4468.misc                            |  1 +
 .../http/federation/matrix_federation_agent.py   | 10 ++++++++++
 synapse/http/matrixfederationclient.py           |  1 -
 .../federation/test_matrix_federation_agent.py   | 16 ++++++++++++++++
 tests/http/test_fedclient.py                     |  2 +-
 5 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 changelog.d/4468.misc

diff --git a/changelog.d/4468.misc b/changelog.d/4468.misc
new file mode 100644
index 0000000000..9a51434755
--- /dev/null
+++ b/changelog.d/4468.misc
@@ -0,0 +1 @@
+Move SRV logic into the Agent layer
diff --git a/synapse/http/federation/matrix_federation_agent.py b/synapse/http/federation/matrix_federation_agent.py
index 0ec28c6696..1788e9a34a 100644
--- a/synapse/http/federation/matrix_federation_agent.py
+++ b/synapse/http/federation/matrix_federation_agent.py
@@ -19,6 +19,7 @@ from zope.interface import implementer
 from twisted.internet import defer
 from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS
 from twisted.web.client import URI, Agent, HTTPConnectionPool
+from twisted.web.http_headers import Headers
 from twisted.web.iweb import IAgent
 
 from synapse.http.endpoint import parse_server_name
@@ -109,6 +110,15 @@ class MatrixFederationAgent(object):
             else:
                 target = pick_server_from_list(server_list)
 
+        # make sure that the Host header is set correctly
+        if headers is None:
+            headers = Headers()
+        else:
+            headers = headers.copy()
+
+        if not headers.hasHeader(b'host'):
+            headers.addRawHeader(b'host', server_name_bytes)
+
         class EndpointFactory(object):
             @staticmethod
             def endpointForURI(_uri):
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 980e912348..bb2e64ed80 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -255,7 +255,6 @@ class MatrixFederationHttpClient(object):
 
         headers_dict = {
             b"User-Agent": [self.version_string_bytes],
-            b"Host": [destination_bytes],
         }
 
         with limiter:
diff --git a/tests/http/federation/test_matrix_federation_agent.py b/tests/http/federation/test_matrix_federation_agent.py
index b32d7566a5..261afb5f41 100644
--- a/tests/http/federation/test_matrix_federation_agent.py
+++ b/tests/http/federation/test_matrix_federation_agent.py
@@ -131,6 +131,10 @@ class MatrixFederationAgentTests(TestCase):
         request = http_server.requests[0]
         self.assertEqual(request.method, b'GET')
         self.assertEqual(request.path, b'/foo/bar')
+        self.assertEqual(
+            request.requestHeaders.getRawHeaders(b'host'),
+            [b'testserv:8448']
+        )
         content = request.content.read()
         self.assertEqual(content, b'')
 
@@ -195,6 +199,10 @@ class MatrixFederationAgentTests(TestCase):
         request = http_server.requests[0]
         self.assertEqual(request.method, b'GET')
         self.assertEqual(request.path, b'/foo/bar')
+        self.assertEqual(
+            request.requestHeaders.getRawHeaders(b'host'),
+            [b'1.2.3.4'],
+        )
 
         # finish the request
         request.finish()
@@ -235,6 +243,10 @@ class MatrixFederationAgentTests(TestCase):
         request = http_server.requests[0]
         self.assertEqual(request.method, b'GET')
         self.assertEqual(request.path, b'/foo/bar')
+        self.assertEqual(
+            request.requestHeaders.getRawHeaders(b'host'),
+            [b'testserv'],
+        )
 
         # finish the request
         request.finish()
@@ -276,6 +288,10 @@ class MatrixFederationAgentTests(TestCase):
         request = http_server.requests[0]
         self.assertEqual(request.method, b'GET')
         self.assertEqual(request.path, b'/foo/bar')
+        self.assertEqual(
+            request.requestHeaders.getRawHeaders(b'host'),
+            [b'testserv'],
+        )
 
         # finish the request
         request.finish()
diff --git a/tests/http/test_fedclient.py b/tests/http/test_fedclient.py
index d37f8f9981..018c77ebcd 100644
--- a/tests/http/test_fedclient.py
+++ b/tests/http/test_fedclient.py
@@ -49,7 +49,6 @@ class FederationClientTests(HomeserverTestCase):
         return hs
 
     def prepare(self, reactor, clock, homeserver):
-
         self.cl = MatrixFederationHttpClient(self.hs)
         self.reactor.lookups["testserv"] = "1.2.3.4"
 
@@ -95,6 +94,7 @@ class FederationClientTests(HomeserverTestCase):
 
         # that should have made it send the request to the transport
         self.assertRegex(transport.value(), b"^GET /foo/bar")
+        self.assertRegex(transport.value(), b"Host: testserv:8008")
 
         # Deferred is still without a result
         self.assertNoResult(test_d)

From 4a3f1388328f8181c33b74a6a777ab2073d400d8 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Fri, 25 Jan 2019 13:57:52 +0000
Subject: [PATCH 11/11] Fix quoting for allowed_local_3pids example config
 (#4476)

If you use double-quotes here, you have to escape your backslashes. It's much
easier with single-quotes.

(Note that the existing double-backslashes are already interpreted by python's
""" parsing.)
---
 changelog.d/4476.misc          | 1 +
 synapse/config/registration.py | 6 +++---
 2 files changed, 4 insertions(+), 3 deletions(-)
 create mode 100644 changelog.d/4476.misc

diff --git a/changelog.d/4476.misc b/changelog.d/4476.misc
new file mode 100644
index 0000000000..a070e10c7c
--- /dev/null
+++ b/changelog.d/4476.misc
@@ -0,0 +1 @@
+Fix quoting for allowed_local_3pids example config
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index fe520d6855..d808a989f3 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -84,11 +84,11 @@ class RegistrationConfig(Config):
         #
         # allowed_local_3pids:
         #     - medium: email
-        #       pattern: ".*@matrix\\.org"
+        #       pattern: '.*@matrix\\.org'
         #     - medium: email
-        #       pattern: ".*@vector\\.im"
+        #       pattern: '.*@vector\\.im'
         #     - medium: msisdn
-        #       pattern: "\\+44"
+        #       pattern: '\\+44'
 
         # If set, allows registration by anyone who also has the shared
         # secret, even if registration is otherwise disabled.