From 407cf076469907029c165b295b98f192f08ac8d0 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 16:36:33 +0100
Subject: [PATCH 01/16] Add config option for setting homeserver's default room
 version

---
 synapse/api/room_versions.py                  |  8 ++--
 synapse/config/homeserver.py                  |  3 +-
 synapse/config/room.py                        | 43 +++++++++++++++++++
 synapse/handlers/room.py                      |  6 ++-
 synapse/rest/client/v2_alpha/capabilities.py  |  5 ++-
 .../rest/client/v2_alpha/test_capabilities.py |  7 ++-
 6 files changed, 61 insertions(+), 11 deletions(-)
 create mode 100644 synapse/config/room.py

diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index 485b3d0237b9..f62f28109e26 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -85,10 +85,6 @@ class RoomVersions(object):
     )
 
 
-# the version we will give rooms which are created on this server
-DEFAULT_ROOM_VERSION = RoomVersions.V1
-
-
 KNOWN_ROOM_VERSIONS = {
     v.identifier: v for v in (
         RoomVersions.V1,
@@ -98,3 +94,7 @@ class RoomVersions(object):
         RoomVersions.EVENTID_NOSLASH_TEST,
     )
 }   # type: dict[str, RoomVersion]
+
+# the version we will give rooms which are created on this server
+def get_default_room_version(config):
+    return KNOWN_ROOM_VERSIONS[config.default_room_version]
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py
index 727fdc54d8b9..cf1d41339734 100644
--- a/synapse/config/homeserver.py
+++ b/synapse/config/homeserver.py
@@ -32,6 +32,7 @@
 from .registration import RegistrationConfig
 from .repository import ContentRepositoryConfig
 from .room_directory import RoomDirectoryConfig
+from .room import RoomConfig
 from .saml2_config import SAML2Config
 from .server import ServerConfig
 from .server_notices_config import ServerNoticesConfig
@@ -50,6 +51,6 @@ class HomeServerConfig(ServerConfig, TlsConfig, DatabaseConfig, LoggingConfig,
                        WorkerConfig, PasswordAuthProviderConfig, PushConfig,
                        SpamCheckerConfig, GroupsConfig, UserDirectoryConfig,
                        ConsentConfig,
-                       ServerNoticesConfig, RoomDirectoryConfig,
+                       ServerNoticesConfig, RoomDirectoryConfig, RoomConfig,
                        ):
     pass
diff --git a/synapse/config/room.py b/synapse/config/room.py
new file mode 100644
index 000000000000..e7c5317ac2a3
--- /dev/null
+++ b/synapse/config/room.py
@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# 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 ._base import Config, ConfigError
+
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
+
+
+class RoomConfig(Config):
+    def read_config(self, config):
+        self.default_room_version = config.get(
+            "default_room_version", "1",
+        )
+
+        if self.default_room_version not in KNOWN_ROOM_VERSIONS:
+            raise ConfigError(
+                "Unknown default_room_version: %s, known room versions: %s" %
+                (self.default_room_version, KNOWN_ROOM_VERSIONS.keys)
+            )
+
+    def default_config(self, config_dir_path, server_name, **kwargs):
+        return """
+        # The default room version for newly created rooms.
+        #
+        # Known room versions are listed here:
+        # https://matrix.org/docs/spec/#complete-list-of-room-versions
+        #
+        # For example, for room version 1, default_room_version should be set
+        # to "1".
+        default_room_version: "1"
+        """
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index e37ae968998a..3997ecaaca0e 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -27,7 +27,7 @@
 
 from synapse.api.constants import EventTypes, JoinRules, RoomCreationPreset
 from synapse.api.errors import AuthError, Codes, NotFoundError, StoreError, SynapseError
-from synapse.api.room_versions import DEFAULT_ROOM_VERSION, KNOWN_ROOM_VERSIONS
+from synapse.api.room_versions import get_default_room_version, KNOWN_ROOM_VERSIONS
 from synapse.storage.state import StateFilter
 from synapse.types import RoomAlias, RoomID, RoomStreamToken, StreamToken, UserID
 from synapse.util import stringutils
@@ -70,6 +70,7 @@ def __init__(self, hs):
         self.spam_checker = hs.get_spam_checker()
         self.event_creation_handler = hs.get_event_creation_handler()
         self.room_member_handler = hs.get_room_member_handler()
+        self.config = hs.config
 
         # linearizer to stop two upgrades happening at once
         self._upgrade_linearizer = Linearizer("room_upgrade_linearizer")
@@ -475,7 +476,8 @@ def create_room(self, requester, config, ratelimit=True,
         if ratelimit:
             yield self.ratelimit(requester)
 
-        room_version = config.get("room_version", DEFAULT_ROOM_VERSION.identifier)
+        default_room_version = get_default_room_version(self.config)
+        room_version = config.get("room_version", default_room_version.identifier)
         if not isinstance(room_version, string_types):
             raise SynapseError(
                 400,
diff --git a/synapse/rest/client/v2_alpha/capabilities.py b/synapse/rest/client/v2_alpha/capabilities.py
index a868d06098b1..4dcc02f97371 100644
--- a/synapse/rest/client/v2_alpha/capabilities.py
+++ b/synapse/rest/client/v2_alpha/capabilities.py
@@ -16,7 +16,7 @@
 
 from twisted.internet import defer
 
-from synapse.api.room_versions import DEFAULT_ROOM_VERSION, KNOWN_ROOM_VERSIONS
+from synapse.api.room_versions import get_default_room_version, KNOWN_ROOM_VERSIONS
 from synapse.http.servlet import RestServlet
 
 from ._base import client_v2_patterns
@@ -36,6 +36,7 @@ def __init__(self, hs):
         """
         super(CapabilitiesRestServlet, self).__init__()
         self.hs = hs
+        self.config = hs.config
         self.auth = hs.get_auth()
         self.store = hs.get_datastore()
 
@@ -48,7 +49,7 @@ def on_GET(self, request):
         response = {
             "capabilities": {
                 "m.room_versions": {
-                    "default": DEFAULT_ROOM_VERSION.identifier,
+                    "default": get_default_room_version(self.config).identifier,
                     "available": {
                         v.identifier: v.disposition
                         for v in KNOWN_ROOM_VERSIONS.values()
diff --git a/tests/rest/client/v2_alpha/test_capabilities.py b/tests/rest/client/v2_alpha/test_capabilities.py
index f3ef977404ab..484fd7b7527c 100644
--- a/tests/rest/client/v2_alpha/test_capabilities.py
+++ b/tests/rest/client/v2_alpha/test_capabilities.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import synapse.rest.admin
-from synapse.api.room_versions import DEFAULT_ROOM_VERSION, KNOWN_ROOM_VERSIONS
+from synapse.api.room_versions import get_default_room_version, KNOWN_ROOM_VERSIONS
 from synapse.rest.client.v1 import login
 from synapse.rest.client.v2_alpha import capabilities
 
@@ -32,6 +32,7 @@ def make_homeserver(self, reactor, clock):
         self.url = b"/_matrix/client/r0/capabilities"
         hs = self.setup_test_homeserver()
         self.store = hs.get_datastore()
+        self.config = hs.config()
         return hs
 
     def test_check_auth_required(self):
@@ -51,8 +52,10 @@ def test_get_room_version_capabilities(self):
         self.assertEqual(channel.code, 200)
         for room_version in capabilities['m.room_versions']['available'].keys():
             self.assertTrue(room_version in KNOWN_ROOM_VERSIONS, "" + room_version)
+
+        default_room_version = get_default_room_version(self.config)
         self.assertEqual(
-            DEFAULT_ROOM_VERSION.identifier, capabilities['m.room_versions']['default']
+            default_room_version.identifier, capabilities['m.room_versions']['default']
         )
 
     def test_get_change_password_capabilities(self):

From 92c2f73cc048d70914c977a82436af7b727ebd59 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 16:39:36 +0100
Subject: [PATCH 02/16] Add changelog

---
 changelog.d/5223.feature | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/5223.feature

diff --git a/changelog.d/5223.feature b/changelog.d/5223.feature
new file mode 100644
index 000000000000..cfdf1ad41ba5
--- /dev/null
+++ b/changelog.d/5223.feature
@@ -0,0 +1 @@
+Ability to configure default room version.

From 7efcd3efbc2fad39c7d60df83e8ce11a53601148 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 16:40:43 +0100
Subject: [PATCH 03/16] lint

---
 synapse/api/room_versions.py                 | 2 ++
 synapse/config/homeserver.py                 | 2 +-
 synapse/config/room.py                       | 4 ++--
 synapse/handlers/room.py                     | 2 +-
 synapse/rest/client/v2_alpha/capabilities.py | 2 +-
 5 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index f62f28109e26..319ff21c569c 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -95,6 +95,8 @@ class RoomVersions(object):
     )
 }   # type: dict[str, RoomVersion]
 
+
 # the version we will give rooms which are created on this server
+# can be overridden by the config
 def get_default_room_version(config):
     return KNOWN_ROOM_VERSIONS[config.default_room_version]
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py
index cf1d41339734..d5d27346293a 100644
--- a/synapse/config/homeserver.py
+++ b/synapse/config/homeserver.py
@@ -31,8 +31,8 @@
 from .ratelimiting import RatelimitConfig
 from .registration import RegistrationConfig
 from .repository import ContentRepositoryConfig
-from .room_directory import RoomDirectoryConfig
 from .room import RoomConfig
+from .room_directory import RoomDirectoryConfig
 from .saml2_config import SAML2Config
 from .server import ServerConfig
 from .server_notices_config import ServerNoticesConfig
diff --git a/synapse/config/room.py b/synapse/config/room.py
index e7c5317ac2a3..6a3ae9b8228b 100644
--- a/synapse/config/room.py
+++ b/synapse/config/room.py
@@ -13,10 +13,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ._base import Config, ConfigError
-
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 
+from ._base import Config, ConfigError
+
 
 class RoomConfig(Config):
     def read_config(self, config):
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 3997ecaaca0e..45bcfcce5633 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -27,7 +27,7 @@
 
 from synapse.api.constants import EventTypes, JoinRules, RoomCreationPreset
 from synapse.api.errors import AuthError, Codes, NotFoundError, StoreError, SynapseError
-from synapse.api.room_versions import get_default_room_version, KNOWN_ROOM_VERSIONS
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, get_default_room_version
 from synapse.storage.state import StateFilter
 from synapse.types import RoomAlias, RoomID, RoomStreamToken, StreamToken, UserID
 from synapse.util import stringutils
diff --git a/synapse/rest/client/v2_alpha/capabilities.py b/synapse/rest/client/v2_alpha/capabilities.py
index 4dcc02f97371..90733cc785d2 100644
--- a/synapse/rest/client/v2_alpha/capabilities.py
+++ b/synapse/rest/client/v2_alpha/capabilities.py
@@ -16,7 +16,7 @@
 
 from twisted.internet import defer
 
-from synapse.api.room_versions import get_default_room_version, KNOWN_ROOM_VERSIONS
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, get_default_room_version
 from synapse.http.servlet import RestServlet
 
 from ._base import client_v2_patterns

From d345b22d0fc7256841168b0e9c3362526465dbac Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 16:42:48 +0100
Subject: [PATCH 04/16] lint2

---
 tests/rest/client/v2_alpha/test_capabilities.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/rest/client/v2_alpha/test_capabilities.py b/tests/rest/client/v2_alpha/test_capabilities.py
index 484fd7b7527c..cbf90903cdf9 100644
--- a/tests/rest/client/v2_alpha/test_capabilities.py
+++ b/tests/rest/client/v2_alpha/test_capabilities.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import synapse.rest.admin
-from synapse.api.room_versions import get_default_room_version, KNOWN_ROOM_VERSIONS
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, get_default_room_version
 from synapse.rest.client.v1 import login
 from synapse.rest.client.v2_alpha import capabilities
 

From 78e8e58be594df138b150b018855e1ef88243bbd Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 16:53:57 +0100
Subject: [PATCH 05/16] Single lookup. Remove separate RoomConfig

---
 synapse/api/room_versions.py |  7 ++++--
 synapse/config/homeserver.py |  3 +--
 synapse/config/room.py       | 43 ------------------------------------
 synapse/config/server.py     | 19 ++++++++++++++++
 4 files changed, 25 insertions(+), 47 deletions(-)
 delete mode 100644 synapse/config/room.py

diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index 319ff21c569c..1c3bab51782b 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -95,8 +95,11 @@ class RoomVersions(object):
     )
 }   # type: dict[str, RoomVersion]
 
-
 # the version we will give rooms which are created on this server
 # can be overridden by the config
+_default_room_version = None
 def get_default_room_version(config):
-    return KNOWN_ROOM_VERSIONS[config.default_room_version]
+    if _default_room_version:
+        _default_room_version = KNOWN_ROOM_VERSIONS[config.default_room_version]
+
+    return _default_room_version
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py
index d5d27346293a..727fdc54d8b9 100644
--- a/synapse/config/homeserver.py
+++ b/synapse/config/homeserver.py
@@ -31,7 +31,6 @@
 from .ratelimiting import RatelimitConfig
 from .registration import RegistrationConfig
 from .repository import ContentRepositoryConfig
-from .room import RoomConfig
 from .room_directory import RoomDirectoryConfig
 from .saml2_config import SAML2Config
 from .server import ServerConfig
@@ -51,6 +50,6 @@ class HomeServerConfig(ServerConfig, TlsConfig, DatabaseConfig, LoggingConfig,
                        WorkerConfig, PasswordAuthProviderConfig, PushConfig,
                        SpamCheckerConfig, GroupsConfig, UserDirectoryConfig,
                        ConsentConfig,
-                       ServerNoticesConfig, RoomDirectoryConfig, RoomConfig,
+                       ServerNoticesConfig, RoomDirectoryConfig,
                        ):
     pass
diff --git a/synapse/config/room.py b/synapse/config/room.py
deleted file mode 100644
index 6a3ae9b8228b..000000000000
--- a/synapse/config/room.py
+++ /dev/null
@@ -1,43 +0,0 @@
-# -*- coding: utf-8 -*-
-# Copyright 2019 The Matrix.org Foundation C.I.C.
-#
-# 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.api.room_versions import KNOWN_ROOM_VERSIONS
-
-from ._base import Config, ConfigError
-
-
-class RoomConfig(Config):
-    def read_config(self, config):
-        self.default_room_version = config.get(
-            "default_room_version", "1",
-        )
-
-        if self.default_room_version not in KNOWN_ROOM_VERSIONS:
-            raise ConfigError(
-                "Unknown default_room_version: %s, known room versions: %s" %
-                (self.default_room_version, KNOWN_ROOM_VERSIONS.keys)
-            )
-
-    def default_config(self, config_dir_path, server_name, **kwargs):
-        return """
-        # The default room version for newly created rooms.
-        #
-        # Known room versions are listed here:
-        # https://matrix.org/docs/spec/#complete-list-of-room-versions
-        #
-        # For example, for room version 1, default_room_version should be set
-        # to "1".
-        default_room_version: "1"
-        """
diff --git a/synapse/config/server.py b/synapse/config/server.py
index f34aa42afa20..cd1921e4c44d 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -88,6 +88,16 @@ def read_config(self, config):
             "restrict_public_rooms_to_local_users", False,
         )
 
+        self.default_room_version = config.get(
+            "default_room_version", "1",
+        )
+
+        if self.default_room_version not in KNOWN_ROOM_VERSIONS:
+            raise ConfigError(
+                "Unknown default_room_version: %s, known room versions: %s" %
+                (self.default_room_version, KNOWN_ROOM_VERSIONS.keys)
+            )
+
         # whether to enable search. If disabled, new entries will not be inserted
         # into the search tables and they will not be indexed. Users will receive
         # errors when attempting to search for messages.
@@ -384,6 +394,15 @@ def default_config(self, server_name, data_dir_path, **kwargs):
         #
         #restrict_public_rooms_to_local_users: true
 
+        # The default room version for newly created rooms.
+        #
+        # Known room versions are listed here:
+        # https://matrix.org/docs/spec/#complete-list-of-room-versions
+        #
+        # For example, for room version 1, default_room_version should be set
+        # to "1".
+        default_room_version: "1"
+
         # The GC threshold parameters to pass to `gc.set_threshold`, if defined
         #
         #gc_thresholds: [700, 10, 10]

From b0daa728f1498ea4318c6c49f84e8ef88e3adaeb Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 17:08:51 +0100
Subject: [PATCH 06/16] lint and clean

---
 synapse/api/room_versions.py | 7 ++-----
 synapse/config/server.py     | 4 ++++
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index 1c3bab51782b..4c70e1b09588 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -95,11 +95,8 @@ class RoomVersions(object):
     )
 }   # type: dict[str, RoomVersion]
 
+
 # the version we will give rooms which are created on this server
 # can be overridden by the config
-_default_room_version = None
 def get_default_room_version(config):
-    if _default_room_version:
-        _default_room_version = KNOWN_ROOM_VERSIONS[config.default_room_version]
-
-    return _default_room_version
+    return config.default_room_version
diff --git a/synapse/config/server.py b/synapse/config/server.py
index cd1921e4c44d..0c906a4d1d48 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -20,6 +20,7 @@
 
 from netaddr import IPSet
 
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.http.endpoint import parse_and_validate_server_name
 from synapse.python_dependencies import DependencyException, check_requirements
 
@@ -98,6 +99,9 @@ def read_config(self, config):
                 (self.default_room_version, KNOWN_ROOM_VERSIONS.keys)
             )
 
+        # Get the actual room version object rather than just the identifier
+        self.default_room_version = KNOWN_ROOM_VERSIONS[self.default_room_version]
+
         # whether to enable search. If disabled, new entries will not be inserted
         # into the search tables and they will not be indexed. Users will receive
         # errors when attempting to search for messages.

From 52f926b901a50e7400c37fe8f8ec15021f55ef01 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 17:17:01 +0100
Subject: [PATCH 07/16] sample config

---
 docs/sample_config.yaml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index f658ec8ecdb0..43da8e28eaef 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -83,6 +83,15 @@ pid_file: DATADIR/homeserver.pid
 #
 #restrict_public_rooms_to_local_users: true
 
+# The default room version for newly created rooms.
+#
+# Known room versions are listed here:
+# https://matrix.org/docs/spec/#complete-list-of-room-versions
+#
+# For example, for room version 1, default_room_version should be set
+# to "1".
+default_room_version: "1"
+
 # The GC threshold parameters to pass to `gc.set_threshold`, if defined
 #
 #gc_thresholds: [700, 10, 10]

From bd6bb52c911b10e43f988598e86e343ed1730ca6 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 17:32:07 +0100
Subject: [PATCH 08/16] typo

---
 tests/rest/client/v2_alpha/test_capabilities.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/rest/client/v2_alpha/test_capabilities.py b/tests/rest/client/v2_alpha/test_capabilities.py
index cbf90903cdf9..a27f2251057f 100644
--- a/tests/rest/client/v2_alpha/test_capabilities.py
+++ b/tests/rest/client/v2_alpha/test_capabilities.py
@@ -32,7 +32,7 @@ def make_homeserver(self, reactor, clock):
         self.url = b"/_matrix/client/r0/capabilities"
         hs = self.setup_test_homeserver()
         self.store = hs.get_datastore()
-        self.config = hs.config()
+        self.config = hs.config
         return hs
 
     def test_check_auth_required(self):

From add13751e49ee3d678d146e0300d235cb77ee77c Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Tue, 21 May 2019 19:57:22 +0100
Subject: [PATCH 09/16] Single, simple point for default room version change

---
 synapse/config/server.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/synapse/config/server.py b/synapse/config/server.py
index 0c906a4d1d48..b4369a958f05 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -36,6 +36,8 @@
 # in the list.
 DEFAULT_BIND_ADDRESSES = ['::', '0.0.0.0']
 
+DEFAULT_ROOM_VERSION = "1"
+
 
 class ServerConfig(Config):
 
@@ -90,7 +92,7 @@ def read_config(self, config):
         )
 
         self.default_room_version = config.get(
-            "default_room_version", "1",
+            "default_room_version", DEFAULT_ROOM_VERSION,
         )
 
         if self.default_room_version not in KNOWN_ROOM_VERSIONS:
@@ -405,7 +407,7 @@ def default_config(self, server_name, data_dir_path, **kwargs):
         #
         # For example, for room version 1, default_room_version should be set
         # to "1".
-        default_room_version: "1"
+        default_room_version: %(DEFAULT_ROOM_VERSION)s
 
         # The GC threshold parameters to pass to `gc.set_threshold`, if defined
         #

From 4d31165086b9f51ba46523bfb2320bf08ba14c30 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Wed, 22 May 2019 09:30:36 +0100
Subject: [PATCH 10/16] Punctuation

---
 synapse/api/room_versions.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index 4c70e1b09588..f8dd28cd5418 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -96,7 +96,7 @@ class RoomVersions(object):
 }   # type: dict[str, RoomVersion]
 
 
-# the version we will give rooms which are created on this server
+# the version we will give rooms which are created on this server.
 # can be overridden by the config
 def get_default_room_version(config):
     return config.default_room_version

From d56c059f22b7792c1db64fbddc10c9b624c7d40e Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Wed, 22 May 2019 09:52:51 +0100
Subject: [PATCH 11/16] Fix config file

---
 docs/sample_config.yaml  |  4 ++--
 synapse/config/server.py | 10 +++++-----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 43da8e28eaef..fe63a9367cfa 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -89,8 +89,8 @@ pid_file: DATADIR/homeserver.pid
 # https://matrix.org/docs/spec/#complete-list-of-room-versions
 #
 # For example, for room version 1, default_room_version should be set
-# to "1".
-default_room_version: "1"
+# to "1". Make sure the value is wrapped in quotes.
+default_room_version: '1'
 
 # The GC threshold parameters to pass to `gc.set_threshold`, if defined
 #
diff --git a/synapse/config/server.py b/synapse/config/server.py
index b4369a958f05..31a66bf24469 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -23,6 +23,7 @@
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.http.endpoint import parse_and_validate_server_name
 from synapse.python_dependencies import DependencyException, check_requirements
+from synapse.util.dictutils import merge_dicts
 
 from ._base import Config, ConfigError
 
@@ -98,7 +99,7 @@ def read_config(self, config):
         if self.default_room_version not in KNOWN_ROOM_VERSIONS:
             raise ConfigError(
                 "Unknown default_room_version: %s, known room versions: %s" %
-                (self.default_room_version, KNOWN_ROOM_VERSIONS.keys)
+                (self.default_room_version, list(KNOWN_ROOM_VERSIONS.keys()))
             )
 
         # Get the actual room version object rather than just the identifier
@@ -406,8 +407,8 @@ def default_config(self, server_name, data_dir_path, **kwargs):
         # https://matrix.org/docs/spec/#complete-list-of-room-versions
         #
         # For example, for room version 1, default_room_version should be set
-        # to "1".
-        default_room_version: %(DEFAULT_ROOM_VERSION)s
+        # to "1". Make sure the value is wrapped in quotes.
+        default_room_version: '%(DEFAULT_ROOM_VERSION)s'
 
         # The GC threshold parameters to pass to `gc.set_threshold`, if defined
         #
@@ -607,7 +608,7 @@ def default_config(self, server_name, data_dir_path, **kwargs):
         # Defaults to 'true'.
         #
         #allow_per_room_profiles: false
-        """ % locals()
+        """ % merge_dicts(locals(), globals())
 
     def read_arguments(self, args):
         if args.manhole is not None:
@@ -694,7 +695,6 @@ def _warn_if_webclient_configured(listeners):
     'webclient',
 )
 
-
 def _check_resource_config(listeners):
     resource_names = set(
         res_name

From 94677c98626041e60ccb578007f34d7ae1599d5c Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Wed, 22 May 2019 09:54:59 +0100
Subject: [PATCH 12/16] lint

---
 synapse/config/server.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/synapse/config/server.py b/synapse/config/server.py
index 31a66bf24469..0530de1f0461 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -408,7 +408,7 @@ def default_config(self, server_name, data_dir_path, **kwargs):
         #
         # For example, for room version 1, default_room_version should be set
         # to "1". Make sure the value is wrapped in quotes.
-        default_room_version: '%(DEFAULT_ROOM_VERSION)s'
+        default_room_version: "%(DEFAULT_ROOM_VERSION)s"
 
         # The GC threshold parameters to pass to `gc.set_threshold`, if defined
         #
@@ -695,6 +695,7 @@ def _warn_if_webclient_configured(listeners):
     'webclient',
 )
 
+
 def _check_resource_config(listeners):
     resource_names = set(
         res_name

From a080a3ad662da2319e067b1d27dfdc5d937cc9b7 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Wed, 22 May 2019 10:03:46 +0100
Subject: [PATCH 13/16] Address review comments

---
 docs/sample_config.yaml                         |  4 ++--
 synapse/api/room_versions.py                    |  6 ------
 synapse/config/server.py                        | 15 +++++++++------
 synapse/handlers/room.py                        |  9 ++++++---
 synapse/rest/client/v2_alpha/capabilities.py    |  4 ++--
 tests/rest/client/v2_alpha/test_capabilities.py |  6 +++---
 6 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index fe63a9367cfa..f392de36077c 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -89,8 +89,8 @@ pid_file: DATADIR/homeserver.pid
 # https://matrix.org/docs/spec/#complete-list-of-room-versions
 #
 # For example, for room version 1, default_room_version should be set
-# to "1". Make sure the value is wrapped in quotes.
-default_room_version: '1'
+# to "1".
+#default_room_version: "1"
 
 # The GC threshold parameters to pass to `gc.set_threshold`, if defined
 #
diff --git a/synapse/api/room_versions.py b/synapse/api/room_versions.py
index f8dd28cd5418..dbb3ab1e7f3e 100644
--- a/synapse/api/room_versions.py
+++ b/synapse/api/room_versions.py
@@ -94,9 +94,3 @@ class RoomVersions(object):
         RoomVersions.EVENTID_NOSLASH_TEST,
     )
 }   # type: dict[str, RoomVersion]
-
-
-# the version we will give rooms which are created on this server.
-# can be overridden by the config
-def get_default_room_version(config):
-    return config.default_room_version
diff --git a/synapse/config/server.py b/synapse/config/server.py
index 0530de1f0461..2a9ef30b1b5b 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -92,18 +92,21 @@ def read_config(self, config):
             "restrict_public_rooms_to_local_users", False,
         )
 
-        self.default_room_version = config.get(
+        default_room_version = config.get(
             "default_room_version", DEFAULT_ROOM_VERSION,
         )
 
-        if self.default_room_version not in KNOWN_ROOM_VERSIONS:
+        # Ensure room version is a str
+        default_room_version = str(default_room_version)
+
+        if default_room_version not in KNOWN_ROOM_VERSIONS:
             raise ConfigError(
                 "Unknown default_room_version: %s, known room versions: %s" %
-                (self.default_room_version, list(KNOWN_ROOM_VERSIONS.keys()))
+                (default_room_version, list(KNOWN_ROOM_VERSIONS.keys()))
             )
 
         # Get the actual room version object rather than just the identifier
-        self.default_room_version = KNOWN_ROOM_VERSIONS[self.default_room_version]
+        self.default_room_version = KNOWN_ROOM_VERSIONS[default_room_version]
 
         # whether to enable search. If disabled, new entries will not be inserted
         # into the search tables and they will not be indexed. Users will receive
@@ -407,8 +410,8 @@ def default_config(self, server_name, data_dir_path, **kwargs):
         # https://matrix.org/docs/spec/#complete-list-of-room-versions
         #
         # For example, for room version 1, default_room_version should be set
-        # to "1". Make sure the value is wrapped in quotes.
-        default_room_version: "%(DEFAULT_ROOM_VERSION)s"
+        # to "1".
+        #default_room_version: "%(DEFAULT_ROOM_VERSION)s"
 
         # The GC threshold parameters to pass to `gc.set_threshold`, if defined
         #
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 45bcfcce5633..4a17911a87fa 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -27,7 +27,7 @@
 
 from synapse.api.constants import EventTypes, JoinRules, RoomCreationPreset
 from synapse.api.errors import AuthError, Codes, NotFoundError, StoreError, SynapseError
-from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, get_default_room_version
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.storage.state import StateFilter
 from synapse.types import RoomAlias, RoomID, RoomStreamToken, StreamToken, UserID
 from synapse.util import stringutils
@@ -476,8 +476,11 @@ def create_room(self, requester, config, ratelimit=True,
         if ratelimit:
             yield self.ratelimit(requester)
 
-        default_room_version = get_default_room_version(self.config)
-        room_version = config.get("room_version", default_room_version.identifier)
+        room_version = config.get(
+            "room_version",
+            self.config.default_room_version.identifier,
+        )
+
         if not isinstance(room_version, string_types):
             raise SynapseError(
                 400,
diff --git a/synapse/rest/client/v2_alpha/capabilities.py b/synapse/rest/client/v2_alpha/capabilities.py
index 90733cc785d2..2b4892330c4d 100644
--- a/synapse/rest/client/v2_alpha/capabilities.py
+++ b/synapse/rest/client/v2_alpha/capabilities.py
@@ -16,7 +16,7 @@
 
 from twisted.internet import defer
 
-from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, get_default_room_version
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.http.servlet import RestServlet
 
 from ._base import client_v2_patterns
@@ -49,7 +49,7 @@ def on_GET(self, request):
         response = {
             "capabilities": {
                 "m.room_versions": {
-                    "default": get_default_room_version(self.config).identifier,
+                    "default": self.config.default_room_version.identifier,
                     "available": {
                         v.identifier: v.disposition
                         for v in KNOWN_ROOM_VERSIONS.values()
diff --git a/tests/rest/client/v2_alpha/test_capabilities.py b/tests/rest/client/v2_alpha/test_capabilities.py
index a27f2251057f..bce5b0cf4c70 100644
--- a/tests/rest/client/v2_alpha/test_capabilities.py
+++ b/tests/rest/client/v2_alpha/test_capabilities.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import synapse.rest.admin
-from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, get_default_room_version
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.rest.client.v1 import login
 from synapse.rest.client.v2_alpha import capabilities
 
@@ -53,9 +53,9 @@ def test_get_room_version_capabilities(self):
         for room_version in capabilities['m.room_versions']['available'].keys():
             self.assertTrue(room_version in KNOWN_ROOM_VERSIONS, "" + room_version)
 
-        default_room_version = get_default_room_version(self.config)
         self.assertEqual(
-            default_room_version.identifier, capabilities['m.room_versions']['default']
+            self.config.default_room_version.identifier,
+            capabilities['m.room_versions']['default'],
         )
 
     def test_get_change_password_capabilities(self):

From e783dddcfd5c92b523e3e49fb6f5f63b714d7d44 Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Wed, 22 May 2019 10:13:56 +0100
Subject: [PATCH 14/16] Add files

---
 synapse/util/dictutils.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 synapse/util/dictutils.py

diff --git a/synapse/util/dictutils.py b/synapse/util/dictutils.py
new file mode 100644
index 000000000000..71a5ddbe2a93
--- /dev/null
+++ b/synapse/util/dictutils.py
@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# 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.
+
+
+def merge_dicts(*dicts):
+    """Merge multiple dictionaries together and return the result.
+
+    Args:
+        dicts: Variable list of dictionary arguments.
+
+    Returns:
+        Dict: A single dictionary as a result of merging the provided
+            dictionaries.
+    """
+    merged = {}
+    for d in dicts:
+        merged.update(d)
+    return merged

From 687501a6b3c9b7be63200d93d58f7fa4b8a56c6c Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Thu, 23 May 2019 14:02:51 +0100
Subject: [PATCH 15/16] less magic

---
 synapse/config/server.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/synapse/config/server.py b/synapse/config/server.py
index 2a9ef30b1b5b..e9120d4d75e0 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -23,7 +23,6 @@
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.http.endpoint import parse_and_validate_server_name
 from synapse.python_dependencies import DependencyException, check_requirements
-from synapse.util.dictutils import merge_dicts
 
 from ._base import Config, ConfigError
 
@@ -330,6 +329,10 @@ def default_config(self, server_name, data_dir_path, **kwargs):
             unsecure_port = 8008
 
         pid_file = os.path.join(data_dir_path, "homeserver.pid")
+
+        # Bring DEFAULT_ROOM_VERSION into the local-scope for use in the
+        # default config string
+        default_room_version = DEFAULT_ROOM_VERSION
         return """\
         ## Server ##
 
@@ -411,7 +414,7 @@ def default_config(self, server_name, data_dir_path, **kwargs):
         #
         # For example, for room version 1, default_room_version should be set
         # to "1".
-        #default_room_version: "%(DEFAULT_ROOM_VERSION)s"
+        #default_room_version: "%(default_room_version)s"
 
         # The GC threshold parameters to pass to `gc.set_threshold`, if defined
         #
@@ -611,7 +614,7 @@ def default_config(self, server_name, data_dir_path, **kwargs):
         # Defaults to 'true'.
         #
         #allow_per_room_profiles: false
-        """ % merge_dicts(locals(), globals())
+        """ % locals()
 
     def read_arguments(self, args):
         if args.manhole is not None:

From a807f7fb34405a2d0c99f122ced6bba6a272db3b Mon Sep 17 00:00:00 2001
From: Andrew Morgan <andrew@amorgan.xyz>
Date: Thu, 23 May 2019 14:17:37 +0100
Subject: [PATCH 16/16] bye bye dictutils

---
 synapse/util/dictutils.py | 30 ------------------------------
 1 file changed, 30 deletions(-)
 delete mode 100644 synapse/util/dictutils.py

diff --git a/synapse/util/dictutils.py b/synapse/util/dictutils.py
deleted file mode 100644
index 71a5ddbe2a93..000000000000
--- a/synapse/util/dictutils.py
+++ /dev/null
@@ -1,30 +0,0 @@
-# -*- coding: utf-8 -*-
-# Copyright 2019 The Matrix.org Foundation C.I.C.
-#
-# 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.
-
-
-def merge_dicts(*dicts):
-    """Merge multiple dictionaries together and return the result.
-
-    Args:
-        dicts: Variable list of dictionary arguments.
-
-    Returns:
-        Dict: A single dictionary as a result of merging the provided
-            dictionaries.
-    """
-    merged = {}
-    for d in dicts:
-        merged.update(d)
-    return merged