Add some debug to keep track of client state desynchronisation

Fixes https://github.com/element-hq/crypto-internal/issues/179

Cargo.lock

@@ -306,9 +306,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.10.3"
+version = "1.10.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b62dbe01f0b06f9d8dc7d49e05a0785f153b00b2c227856282f671e0318c9b15"
+checksum = "c117dbdfde9c8308975b6a18d71f3f385c89461f7b3fb054288ecf2a2058ba4c"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -367,9 +367,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.114"
+version = "1.0.115"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c5f09b1bd632ef549eaa9f60a1f8de742bdbc698e6cee2095fc84dde5f549ae0"
+checksum = "12dc5c46daa8e9fdf4f5e71b6cf9a53f2487da0e86e55808e2d35539666497dd"
 dependencies = [
  "itoa",
  "ryu",

changelog.d/17022.feature

@@ -0,0 +1 @@
+Stabilize support for [MSC4010](https://github.com/matrix-org/matrix-spec-proposals/pull/4010) which clarifies the interaction of push rules and account data. Contributed by @clokep.

changelog.d/17023.feature

@@ -0,0 +1 @@
+Stabilize support for [MSC3981](https://github.com/matrix-org/matrix-spec-proposals/pull/3981): `/relations` recursion. Contributed by @clokep.

changelog.d/17033.bugfix

@@ -0,0 +1 @@
+Fix server notice rooms not always being created as unencrypted rooms, even when `encryption_enabled_by_default_for_room_type` is in use (server notices are always unencrypted).

changelog.d/17043.bugfix

@@ -0,0 +1 @@
+Fix the `.m.rule.encrypted_room_one_to_one` and `.m.rule.room_one_to_one` default underride push rules being in the wrong order. Contributed by @Sumpy1.

changelog.d/17054.misc

@@ -0,0 +1 @@
+Improve database performance by adding a missing index to `access_tokens.refresh_token_id`.

changelog.d/17058.doc

@@ -1 +0,0 @@
-Document [`/v1/make_knock`](https://spec.matrix.org/v1.10/server-server-api/#get_matrixfederationv1make_knockroomiduserid) and [`/v1/send_knock/](https://spec.matrix.org/v1.10/server-server-api/#put_matrixfederationv1send_knockroomideventid) federation endpoints as worker-compatible.

changelog.d/17064.bugfix

@@ -0,0 +1 @@
+Fix various long-standing bugs which could cause incorrect state to be returned from `/sync` in certain situations.

changelog.d/17065.bugfix

@@ -0,0 +1 @@
+Fix various long-standing bugs which could cause incorrect state to be returned from `/sync` in certain situations.

changelog.d/17066.bugfix

@@ -0,0 +1 @@
+Fix various long-standing bugs which could cause incorrect state to be returned from `/sync` in certain situations.

docs/workers.md

@@ -211,8 +211,6 @@ information.
     ^/_matrix/federation/v1/make_leave/
     ^/_matrix/federation/(v1|v2)/send_join/
     ^/_matrix/federation/(v1|v2)/send_leave/
-    ^/_matrix/federation/v1/make_knock/
-    ^/_matrix/federation/v1/send_knock/
     ^/_matrix/federation/(v1|v2)/invite/
     ^/_matrix/federation/v1/event_auth/
     ^/_matrix/federation/v1/timestamp_to_event/

poetry.lock

@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 1.7.1 and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.8.2 and should not be changed by hand.
 
 [[package]]
 name = "alabaster"
@@ -1602,13 +1602,13 @@ tests = ["Sphinx", "doubles", "flake8", "flake8-quotes", "gevent", "mock", "pyte
 
 [[package]]
 name = "packaging"
-version = "23.2"
+version = "24.0"
 description = "Core utilities for Python packages"
 optional = false
 python-versions = ">=3.7"
 files = [
-    {file = "packaging-23.2-py3-none-any.whl", hash = "sha256:8c491190033a9af7e1d931d0b5dacc2ef47509b34dd0de67ed209b5203fc88c7"},
-    {file = "packaging-23.2.tar.gz", hash = "sha256:048fb0e9405036518eaaf48a55953c750c11e1a1b68e0dd1a9d62ed0c092cfc5"},
+    {file = "packaging-24.0-py3-none-any.whl", hash = "sha256:2ddfb553fdf02fb784c234c7ba6ccc288296ceabec964ad2eae3777778130bc5"},
+    {file = "packaging-24.0.tar.gz", hash = "sha256:eb82c5e3e56209074766e6885bb04b8c38a0c015d0a30036ebe7ece34c9989e9"},
 ]
 
 [[package]]
@@ -2444,28 +2444,28 @@ files = [
 
 [[package]]
 name = "ruff"
-version = "0.3.2"
+version = "0.3.5"
 description = "An extremely fast Python linter and code formatter, written in Rust."
 optional = false
 python-versions = ">=3.7"
 files = [
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-    {file = "ruff-0.3.2-py3-none-macosx_10_12_x86_64.whl", hash = "sha256:9966b964b2dd1107797be9ca7195002b874424d1d5472097701ae8f43eadef5d"},
-    {file = "ruff-0.3.2-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:b83d17ff166aa0659d1e1deaf9f2f14cbe387293a906de09bc4860717eb2e2da"},
-    {file = "ruff-0.3.2-py3-none-manylinux_2_17_armv7l.manylinux2014_armv7l.whl", hash = "sha256:bb875c6cc87b3703aeda85f01c9aebdce3d217aeaca3c2e52e38077383f7268a"},
-    {file = "ruff-0.3.2-py3-none-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:be75e468a6a86426430373d81c041b7605137a28f7014a72d2fc749e47f572aa"},
-    {file = "ruff-0.3.2-py3-none-manylinux_2_17_ppc64.manylinux2014_ppc64.whl", hash = "sha256:967978ac2d4506255e2f52afe70dda023fc602b283e97685c8447d036863a302"},
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-    {file = "ruff-0.3.2-py3-none-win_arm64.whl", hash = "sha256:5f65103b1d76e0d600cabd577b04179ff592064eaa451a70a81085930e907d0b"},
-    {file = "ruff-0.3.2.tar.gz", hash = "sha256:fa78ec9418eb1ca3db392811df3376b46471ae93792a81af2d1cbb0e5dcb5142"},
+    {file = "ruff-0.3.5-py3-none-macosx_10_12_x86_64.macosx_11_0_arm64.macosx_10_12_universal2.whl", hash = "sha256:aef5bd3b89e657007e1be6b16553c8813b221ff6d92c7526b7e0227450981eac"},
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+    {file = "ruff-0.3.5-py3-none-musllinux_1_2_x86_64.whl", hash = "sha256:a759d33a20c72f2dfa54dae6e85e1225b8e302e8ac655773aff22e542a300985"},
+    {file = "ruff-0.3.5-py3-none-win32.whl", hash = "sha256:9d8605aa990045517c911726d21293ef4baa64f87265896e491a05461cae078d"},
+    {file = "ruff-0.3.5-py3-none-win_amd64.whl", hash = "sha256:dc56bb16a63c1303bd47563c60482a1512721053d93231cf7e9e1c6954395a0e"},
+    {file = "ruff-0.3.5-py3-none-win_arm64.whl", hash = "sha256:faeeae9905446b975dcf6d4499dc93439b131f1443ee264055c5716dd947af55"},
+    {file = "ruff-0.3.5.tar.gz", hash = "sha256:a067daaeb1dc2baf9b82a32dae67d154d95212080c80435eb052d95da647763d"},
 ]
 
 [[package]]
@@ -3109,13 +3109,13 @@ files = [
 
 [[package]]
 name = "types-pillow"
-version = "10.2.0.20240125"
+version = "10.2.0.20240406"
 description = "Typing stubs for Pillow"
 optional = false
 python-versions = ">=3.8"
 files = [
-    {file = "types-Pillow-10.2.0.20240125.tar.gz", hash = "sha256:c449b2c43b9fdbe0494a7b950e6b39a4e50516091213fec24ef3f33c1d017717"},
-    {file = "types_Pillow-10.2.0.20240125-py3-none-any.whl", hash = "sha256:322dbae32b4b7918da5e8a47c50ac0f24b0aa72a804a23857620f2722b03c858"},
+    {file = "types-Pillow-10.2.0.20240406.tar.gz", hash = "sha256:62e0cc1f17caba40e72e7154a483f4c7f3bea0e1c34c0ebba9de3c7745bc306d"},
+    {file = "types_Pillow-10.2.0.20240406-py3-none-any.whl", hash = "sha256:5ac182e8afce53de30abca2fdf9cbec7b2500e549d0be84da035a729a84c7c47"},
 ]
 
 [[package]]
@@ -3156,13 +3156,13 @@ files = [
 
 [[package]]
 name = "types-requests"
-version = "2.31.0.20240125"
+version = "2.31.0.20240406"
 description = "Typing stubs for requests"
 optional = false
 python-versions = ">=3.8"
 files = [
-    {file = "types-requests-2.31.0.20240125.tar.gz", hash = "sha256:03a28ce1d7cd54199148e043b2079cdded22d6795d19a2c2a6791a4b2b5e2eb5"},
-    {file = "types_requests-2.31.0.20240125-py3-none-any.whl", hash = "sha256:9592a9a4cb92d6d75d9b491a41477272b710e021011a2a3061157e2fb1f1a5d1"},
+    {file = "types-requests-2.31.0.20240406.tar.gz", hash = "sha256:4428df33c5503945c74b3f42e82b181e86ec7b724620419a2966e2de604ce1a1"},
+    {file = "types_requests-2.31.0.20240406-py3-none-any.whl", hash = "sha256:6216cdac377c6b9a040ac1c0404f7284bd13199c0e1bb235f4324627e8898cf5"},
 ]
 
 [package.dependencies]
@@ -3181,13 +3181,13 @@ files = [
 
 [[package]]
 name = "typing-extensions"
-version = "4.9.0"
+version = "4.11.0"
 description = "Backported and Experimental Type Hints for Python 3.8+"
 optional = false
 python-versions = ">=3.8"
 files = [
-    {file = "typing_extensions-4.9.0-py3-none-any.whl", hash = "sha256:af72aea155e91adfc61c3ae9e0e342dbc0cba726d6cba4b6c72c1f34e47291cd"},
-    {file = "typing_extensions-4.9.0.tar.gz", hash = "sha256:23478f88c37f27d76ac8aee6c905017a143b0b1b886c3c9f66bc2fd94f9f5783"},
+    {file = "typing_extensions-4.11.0-py3-none-any.whl", hash = "sha256:c1f94d72897edaf4ce775bb7558d5b79d8126906a14ea5ed1635921406c0387a"},
+    {file = "typing_extensions-4.11.0.tar.gz", hash = "sha256:83f085bd5ca59c80295fc2a82ab5dac679cbe02b9f33f7d83af68e241bea51b0"},
 ]
 
 [[package]]
@@ -3451,4 +3451,4 @@ user-search = ["pyicu"]
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.8.0"
-content-hash = "b510fa05f4ea33194bec079f5d04ebb3f9ffbb5c1ea96a0341d57ba770ef81e6"
+content-hash = "4abda113a01f162bb3978b0372956d569364533aa39f57863c234363f8449a4f"

pyproject.toml

@@ -321,7 +321,7 @@ all = [
 # This helps prevents merge conflicts when running a batch of dependabot updates.
 isort = ">=5.10.1"
 black = ">=22.7.0"
-ruff = "0.3.2"
+ruff = "0.3.5"
 # Type checking only works with the pydantic.v1 compat module from pydantic v2
 pydantic = "^2"
 

rust/src/push/base_rules.rs

@@ -304,12 +304,12 @@ pub const BASE_APPEND_UNDERRIDE_RULES: &[PushRule] = &[
         default_enabled: true,
     },
     PushRule {
-        rule_id: Cow::Borrowed("global/underride/.m.rule.room_one_to_one"),
+        rule_id: Cow::Borrowed("global/underride/.m.rule.encrypted_room_one_to_one"),
         priority_class: 1,
         conditions: Cow::Borrowed(&[
             Condition::Known(KnownCondition::EventMatch(EventMatchCondition {
                 key: Cow::Borrowed("type"),
-                pattern: Cow::Borrowed("m.room.message"),
+                pattern: Cow::Borrowed("m.room.encrypted"),
             })),
             Condition::Known(KnownCondition::RoomMemberCount {
                 is: Some(Cow::Borrowed("2")),
@@ -320,12 +320,12 @@ pub const BASE_APPEND_UNDERRIDE_RULES: &[PushRule] = &[
         default_enabled: true,
     },
     PushRule {
-        rule_id: Cow::Borrowed("global/underride/.m.rule.encrypted_room_one_to_one"),
+        rule_id: Cow::Borrowed("global/underride/.m.rule.room_one_to_one"),
         priority_class: 1,
         conditions: Cow::Borrowed(&[
             Condition::Known(KnownCondition::EventMatch(EventMatchCondition {
                 key: Cow::Borrowed("type"),
-                pattern: Cow::Borrowed("m.room.encrypted"),
+                pattern: Cow::Borrowed("m.room.message"),
             })),
             Condition::Known(KnownCondition::RoomMemberCount {
                 is: Some(Cow::Borrowed("2")),

synapse/config/experimental.py

@@ -393,11 +393,6 @@ class ExperimentalConfig(Config):
         # MSC3967: Do not require UIA when first uploading cross signing keys
         self.msc3967_enabled = experimental.get("msc3967_enabled", False)
 
-        # MSC3981: Recurse relations
-        self.msc3981_recurse_relations = experimental.get(
-            "msc3981_recurse_relations", False
-        )
-
         # MSC3861: Matrix architecture change to delegate authentication via OIDC
         try:
             self.msc3861 = MSC3861(**experimental.get("msc3861", {}))
@@ -409,11 +404,6 @@ class ExperimentalConfig(Config):
         # Check that none of the other config options conflict with MSC3861 when enabled
         self.msc3861.check_config_conflicts(self.root)
 
-        # MSC4010: Do not allow setting m.push_rules account data.
-        self.msc4010_push_rules_account_data = experimental.get(
-            "msc4010_push_rules_account_data", False
-        )
-
         self.msc4028_push_encrypted_events = experimental.get(
             "msc4028_push_encrypted_events", False
         )

synapse/handlers/room.py

@@ -956,6 +956,7 @@ class RoomCreationHandler:
             room_alias=room_alias,
             power_level_content_override=power_level_content_override,
             creator_join_profile=creator_join_profile,
+            ignore_forced_encryption=ignore_forced_encryption,
         )
 
         # we avoid dropping the lock between invites, as otherwise joins can

synapse/handlers/sync.py

@@ -88,6 +88,10 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger(__name__)
 
+# Logging for https://github.com/matrix-org/matrix-spec/issues/1209 and
+# https://github.com/element-hq/synapse/issues/16940
+client_state_desync_logger = logging.getLogger("synapse.client_state_desync_debug")
+
 # Counts the number of times we returned a non-empty sync. `type` is one of
 # "initial_sync", "full_state_sync" or "incremental_sync", `lazy_loaded` is
 # "true" or "false" depending on if the request asked for lazy loaded members or
@@ -1214,6 +1218,12 @@ class SyncHandler:
             previous_timeline_end={},
             lazy_load_members=lazy_load_members,
         )
+
+        if client_state_desync_logger.isEnabledFor(logging.DEBUG):
+            await self._log_client_state_desync(
+                room_id, None, state_ids, timeline_state, lazy_load_members
+            )
+
         return state_ids
 
     async def _compute_state_delta_for_incremental_sync(
@@ -1259,6 +1269,51 @@ class SyncHandler:
             await_full_state = True
             lazy_load_members = False
 
+        # For a non-gappy sync if the events in the timeline are simply a linear
+        # chain (i.e. no merging/branching of the graph), then we know the state
+        # delta between the end of the previous sync and start of the new one is
+        # empty.
+        #
+        # c.f. #16941 for an example of why we can't do this for all non-gappy
+        # syncs.
+        is_linear_timeline = True
+        if batch.events:
+            # We need to make sure the first event in our batch points to the
+            # last event in the previous batch.
+            last_event_id_prev_batch = (
+                await self.store.get_last_event_in_room_before_stream_ordering(
+                    room_id,
+                    end_token=since_token.room_key,
+                )
+            )
+
+            prev_event_id = last_event_id_prev_batch
+            for e in batch.events:
+                if e.prev_event_ids() != [prev_event_id]:
+                    is_linear_timeline = False
+                    break
+                prev_event_id = e.event_id
+
+        if is_linear_timeline and not batch.limited:
+            state_ids: StateMap[str] = {}
+            if lazy_load_members:
+                if members_to_fetch and batch.events:
+                    # We're lazy-loading, so the client might need some more
+                    # member events to understand the events in this timeline.
+                    # So we fish out all the member events corresponding to the
+                    # timeline here. The caller will then dedupe any redundant
+                    # ones.
+
+                    state_ids = await self._state_storage_controller.get_state_ids_for_event(
+                        batch.events[0].event_id,
+                        # we only want members!
+                        state_filter=StateFilter.from_types(
+                            (EventTypes.Member, member) for member in members_to_fetch
+                        ),
+                        await_full_state=False,
+                    )
+            return state_ids
+
         if batch:
             state_at_timeline_start = (
                 await self._state_storage_controller.get_state_ids_for_event(
@@ -1314,6 +1369,15 @@ class SyncHandler:
             lazy_load_members=lazy_load_members,
         )
 
+        if client_state_desync_logger.isEnabledFor(logging.DEBUG):
+            await self._log_client_state_desync(
+                room_id,
+                since_token,
+                state_ids,
+                timeline_state,
+                lazy_load_members,
+            )
+
         return state_ids
 
     async def _find_missing_partial_state_memberships(
@@ -1430,6 +1494,125 @@ class SyncHandler:
 
         return additional_state_ids
 
+    async def _log_client_state_desync(
+        self,
+        room_id: str,
+        since_token: Optional[StreamToken],
+        sync_response_state_state: StateMap[str],
+        sync_response_timeline_state: StateMap[str],
+        lazy_load_members: bool,
+    ) -> None:
+        """
+        Logging to see how often the client's state gets out of sync with the
+        actual current state of the room.
+
+        There are few different potential failure modes here:
+
+         * State resolution can cause changes in the state of the room that don't
+           directly correspond to events with the corresponding (type, state_key).
+           https://github.com/matrix-org/matrix-spec/issues/1209 discusses this in
+           more detail.
+
+         * Even where there is an event that causes a given state change, Synapse
+           may not serve it to the client, since it works on state at specific points
+           in the DAG, rather than "current state".
+           See https://github.com/element-hq/synapse/issues/16940.
+
+         * Lazy-loading adds more complexity, as it means that events that would
+           normally be served via the `state` part of an incremental sync are filtered
+           out.
+
+        To try to get a handle on this, let's put ourselves in the shoes of a client,
+        and compare the state they will calculate against the actual current state.
+        """
+        # We only care about membership events.
+        state_filter = StateFilter.from_types(types=(("m.room.member", None),))
+
+        if since_token is None:
+            if lazy_load_members:
+                # For initial syncs with lazy-loading enabled, there's not too much
+                # concern here. We know the client will do a `/members` query before
+                # doing any encryption, so what sync returns isn't too important.
+                #
+                # (Of course, then `/members` might also return an incomplete list, but
+                # that's a separate problem.)
+                return
+
+            # For regular initial syncs, compare the returned response with the actual
+            # current state.
+            client_calculated_state = {}
+            client_calculated_state.update(sync_response_state_state)
+            client_calculated_state.update(sync_response_timeline_state)
+        else:
+            # For an incremental (gappy or otherwise) sync, let's assume the client has
+            # a complete membership list as of the last sync (or rather, at
+            # `since_token`, which is the closest approximation we have to it
+            # right now), and see what they would calculate as the current state given
+            # this sync update.
+
+            client_calculated_state = dict(
+                await self.get_state_at(
+                    room_id,
+                    stream_position=since_token,
+                    state_filter=state_filter,
+                    await_full_state=False,
+                )
+            )
+            client_calculated_state.update(sync_response_state_state)
+            client_calculated_state.update(sync_response_timeline_state)
+
+        current_state = await self._state_storage_controller.get_current_state_ids(
+            room_id, state_filter=state_filter, await_full_state=False
+        )
+        missing_users = await self._calculate_missing_members(
+            current_state, client_calculated_state
+        )
+        if missing_users:
+            client_state_desync_logger.debug(
+                "client state discrepancy in incremental sync in room %s: missing users %s",
+                room_id,
+                missing_users,
+            )
+
+    async def _calculate_missing_members(
+        self,
+        actual_state: StateMap[str],
+        client_calculated_state: StateMap[str],
+    ) -> List[str]:
+        """Helper for `_log_client_state_desync`: calculates the difference in
+        joined members between two state maps.
+
+        Returns:
+            A list of user IDs
+        """
+        missing_users = []
+
+        async def event_id_to_membership(event_id: Optional[str]) -> Optional[str]:
+            if event_id is None:
+                return None
+            event = await self.store.get_event(event_id, allow_none=True)
+            if event is None:
+                return "MISSING_EVENT"
+            return event.membership
+
+        # Check for joined members in the actual state that are missing or have a
+        # different membership in the actual state.
+        for (event_type, state_key), actual_event_id in actual_state.items():
+            if event_type != EventTypes.Member:
+                continue
+
+            calculated_event_id = client_calculated_state.get((event_type, state_key))
+            if calculated_event_id != actual_event_id:
+                actual_membership = event_id_to_membership(actual_event_id)
+                calculated_membership = event_id_to_membership(calculated_event_id)
+                if (
+                    actual_membership == Membership.JOIN
+                    and calculated_membership != Membership.JOIN
+                ):
+                    missing_users.append(state_key)
+
+        return missing_users
+
     async def unread_notifs_for_room_id(
         self, room_id: str, sync_config: SyncConfig
     ) -> RoomNotifCounts:

synapse/rest/client/account_data.py

@@ -81,8 +81,7 @@ class AccountDataServlet(RestServlet):
             raise AuthError(403, "Cannot add account data for other users.")
 
         # Raise an error if the account data type cannot be set directly.
-        if self._hs.config.experimental.msc4010_push_rules_account_data:
-            _check_can_set_account_data_type(account_data_type)
+        _check_can_set_account_data_type(account_data_type)
 
         body = parse_json_object_from_request(request)
 
@@ -108,10 +107,7 @@ class AccountDataServlet(RestServlet):
             raise AuthError(403, "Cannot get account data for other users.")
 
         # Push rules are stored in a separate table and must be queried separately.
-        if (
-            self._hs.config.experimental.msc4010_push_rules_account_data
-            and account_data_type == AccountDataTypes.PUSH_RULES
-        ):
+        if account_data_type == AccountDataTypes.PUSH_RULES:
             account_data: Optional[JsonMapping] = (
                 await self._push_rules_handler.push_rules_for_user(requester.user)
             )
@@ -162,8 +158,7 @@ class UnstableAccountDataServlet(RestServlet):
             raise AuthError(403, "Cannot delete account data for other users.")
 
         # Raise an error if the account data type cannot be set directly.
-        if self._hs.config.experimental.msc4010_push_rules_account_data:
-            _check_can_set_account_data_type(account_data_type)
+        _check_can_set_account_data_type(account_data_type)
 
         await self.handler.remove_account_data_for_user(user_id, account_data_type)
 
@@ -209,15 +204,7 @@ class RoomAccountDataServlet(RestServlet):
             )
 
         # Raise an error if the account data type cannot be set directly.
-        if self._hs.config.experimental.msc4010_push_rules_account_data:
-            _check_can_set_account_data_type(account_data_type)
-        elif account_data_type == ReceiptTypes.FULLY_READ:
-            raise SynapseError(
-                405,
-                "Cannot set m.fully_read through this API."
-                " Use /rooms/!roomId:server.name/read_markers",
-                Codes.BAD_JSON,
-            )
+        _check_can_set_account_data_type(account_data_type)
 
         body = parse_json_object_from_request(request)
 
@@ -256,10 +243,7 @@ class RoomAccountDataServlet(RestServlet):
             )
 
         # Room-specific push rules are not currently supported.
-        if (
-            self._hs.config.experimental.msc4010_push_rules_account_data
-            and account_data_type == AccountDataTypes.PUSH_RULES
-        ):
+        if account_data_type == AccountDataTypes.PUSH_RULES:
             account_data: Optional[JsonMapping] = {}
         else:
             account_data = await self.store.get_account_data_for_room_and_type(
@@ -317,8 +301,7 @@ class UnstableRoomAccountDataServlet(RestServlet):
             )
 
         # Raise an error if the account data type cannot be set directly.
-        if self._hs.config.experimental.msc4010_push_rules_account_data:
-            _check_can_set_account_data_type(account_data_type)
+        _check_can_set_account_data_type(account_data_type)
 
         await self.handler.remove_account_data_for_room(
             user_id, room_id, account_data_type

synapse/rest/client/relations.py

@@ -55,7 +55,6 @@ class RelationPaginationServlet(RestServlet):
         self.auth = hs.get_auth()
         self._store = hs.get_datastores().main
         self._relations_handler = hs.get_relations_handler()
-        self._support_recurse = hs.config.experimental.msc3981_recurse_relations
 
     async def on_GET(
         self,
@@ -70,12 +69,9 @@ class RelationPaginationServlet(RestServlet):
         pagination_config = await PaginationConfig.from_request(
             self._store, request, default_limit=5, default_dir=Direction.BACKWARDS
         )
-        if self._support_recurse:
-            recurse = parse_boolean(request, "recurse", default=False) or parse_boolean(
-                request, "org.matrix.msc3981.recurse", default=False
-            )
-        else:
-            recurse = False
+        recurse = parse_boolean(request, "recurse", default=False) or parse_boolean(
+            request, "org.matrix.msc3981.recurse", default=False
+        )
 
         # The unstable version of this API returns an extra field for client
         # compatibility, see https://github.com/matrix-org/synapse/issues/12930.

synapse/rest/client/versions.py

@@ -132,7 +132,8 @@ class VersionsRestServlet(RestServlet):
                     # Adds support for relation-based redactions as per MSC3912.
                     "org.matrix.msc3912": self.config.experimental.msc3912_enabled,
                     # Whether recursively provide relations is supported.
-                    "org.matrix.msc3981": self.config.experimental.msc3981_recurse_relations,
+                    # TODO This is no longer needed once unstable MSC3981 does not need to be supported.
+                    "org.matrix.msc3981": True,
                     # Adds support for deleting account data.
                     "org.matrix.msc3391": self.config.experimental.msc3391_enabled,
                     # Allows clients to inhibit profile update propagation.

synapse/storage/databases/main/registration.py

@@ -2108,6 +2108,13 @@ class RegistrationBackgroundUpdateStore(RegistrationWorkerStore):
             unique=False,
         )
 
+        self.db_pool.updates.register_background_index_update(
+            update_name="access_tokens_refresh_token_id_idx",
+            index_name="access_tokens_refresh_token_id_idx",
+            table="access_tokens",
+            columns=("refresh_token_id",),
+        )
+
     async def _background_update_set_deactivated_flag(
         self, progress: JsonDict, batch_size: int
     ) -> int:
@@ -2266,13 +2273,6 @@ class RegistrationStore(StatsStore, RegistrationBackgroundUpdateStore):
     ):
         super().__init__(database, db_conn, hs)
 
-        self.db_pool.updates.register_background_index_update(
-            update_name="access_tokens_refresh_token_id_idx",
-            index_name="access_tokens_refresh_token_id_idx",
-            table="access_tokens",
-            columns=("refresh_token_id",),
-        )
-
         self._ignore_unknown_session_error = (
             hs.config.server.request_token_inhibit_3pid_errors
         )

synapse/storage/schema/main/delta/84/04_access_token_index.sql

@@ -0,0 +1,15 @@
+--
+-- This file is licensed under the Affero General Public License (AGPL) version 3.
+--
+-- Copyright (C) 2023 New Vector, Ltd
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as
+-- published by the Free Software Foundation, either version 3 of the
+-- License, or (at your option) any later version.
+--
+-- See the GNU Affero General Public License for more details:
+-- <https://www.gnu.org/licenses/agpl-3.0.html>.
+
+INSERT INTO background_updates (ordering, update_name, progress_json) VALUES
+    (8404, 'access_tokens_refresh_token_id_idx', '{}');

tests/handlers/test_sync.py

@@ -435,6 +435,101 @@ class SyncTestCase(tests.unittest.HomeserverTestCase):
             [s2_event],
         )
 
+    def test_state_includes_changes_on_long_lived_forks(self) -> None:
+        """State changes that happen on a fork of the DAG must be included in `state`
+
+        Given the following DAG:
+
+             E1
+           ↗    ↖
+          |      S2
+          |      ↑
+        --|------|----
+          E3     |
+        --|------|----
+          |      E4
+          |      |
+
+        ... and a filter that means we only return 1 event, represented by the dashed
+        horizontal lines: `S2` must be included in the `state` section on the second sync.
+        """
+        alice = self.register_user("alice", "password")
+        alice_tok = self.login(alice, "password")
+        alice_requester = create_requester(alice)
+        room_id = self.helper.create_room_as(alice, is_public=True, tok=alice_tok)
+
+        # Do an initial sync as Alice to get a known starting point.
+        initial_sync_result = self.get_success(
+            self.sync_handler.wait_for_sync_for_user(
+                alice_requester, generate_sync_config(alice)
+            )
+        )
+        last_room_creation_event_id = (
+            initial_sync_result.joined[0].timeline.events[-1].event_id
+        )
+
+        # Send a state event, and a regular event, both using the same prev ID
+        with self._patch_get_latest_events([last_room_creation_event_id]):
+            s2_event = self.helper.send_state(room_id, "s2", {}, tok=alice_tok)[
+                "event_id"
+            ]
+            e3_event = self.helper.send(room_id, "e3", tok=alice_tok)["event_id"]
+
+        # Do an incremental sync, this will return E3 but *not* S2 at this
+        # point.
+        incremental_sync = self.get_success(
+            self.sync_handler.wait_for_sync_for_user(
+                alice_requester,
+                generate_sync_config(
+                    alice,
+                    filter_collection=FilterCollection(
+                        self.hs, {"room": {"timeline": {"limit": 1}}}
+                    ),
+                ),
+                since_token=initial_sync_result.next_batch,
+            )
+        )
+        room_sync = incremental_sync.joined[0]
+        self.assertEqual(room_sync.room_id, room_id)
+        self.assertTrue(room_sync.timeline.limited)
+        self.assertEqual(
+            [e.event_id for e in room_sync.timeline.events],
+            [e3_event],
+        )
+        self.assertEqual(
+            [e.event_id for e in room_sync.state.values()],
+            [],
+        )
+
+        # Now send another event that points to S2, but not E3.
+        with self._patch_get_latest_events([s2_event]):
+            e4_event = self.helper.send(room_id, "e4", tok=alice_tok)["event_id"]
+
+        # Doing an incremental sync should return S2 in state.
+        incremental_sync = self.get_success(
+            self.sync_handler.wait_for_sync_for_user(
+                alice_requester,
+                generate_sync_config(
+                    alice,
+                    filter_collection=FilterCollection(
+                        self.hs, {"room": {"timeline": {"limit": 1}}}
+                    ),
+                ),
+                since_token=incremental_sync.next_batch,
+            )
+        )
+        room_sync = incremental_sync.joined[0]
+        self.assertEqual(room_sync.room_id, room_id)
+        self.assertFalse(room_sync.timeline.limited)
+        self.assertEqual(
+            [e.event_id for e in room_sync.timeline.events],
+            [e4_event],
+        )
+        self.assertEqual(
+            [e.event_id for e in room_sync.state.values()],
+            [s2_event],
+        )
+
     def test_state_includes_changes_on_ungappy_syncs(self) -> None:
         """Test `state` where the sync is not gappy.
 

tests/rest/client/test_relations.py

@@ -35,7 +35,6 @@ from synapse.util import Clock
 from tests import unittest
 from tests.server import FakeChannel
 from tests.test_utils.event_injection import inject_event
-from tests.unittest import override_config
 
 
 class BaseRelationsTestCase(unittest.HomeserverTestCase):
@@ -957,7 +956,6 @@ class RelationPaginationTestCase(BaseRelationsTestCase):
 
 
 class RecursiveRelationTestCase(BaseRelationsTestCase):
-    @override_config({"experimental_features": {"msc3981_recurse_relations": True}})
     def test_recursive_relations(self) -> None:
         """Generate a complex, multi-level relationship tree and query it."""
         # Create a thread with a few messages in it.
@@ -1003,7 +1001,7 @@ class RecursiveRelationTestCase(BaseRelationsTestCase):
         channel = self.make_request(
             "GET",
             f"/_matrix/client/v1/rooms/{self.room}/relations/{self.parent_id}"
-            "?dir=f&limit=20&org.matrix.msc3981.recurse=true",
+            "?dir=f&limit=20&recurse=true",
             access_token=self.user_token,
         )
         self.assertEqual(200, channel.code, channel.json_body)
@@ -1024,7 +1022,6 @@ class RecursiveRelationTestCase(BaseRelationsTestCase):
             ],
         )
 
-    @override_config({"experimental_features": {"msc3981_recurse_relations": True}})
     def test_recursive_relations_with_filter(self) -> None:
         """The event_type and rel_type still apply."""
         # Create a thread with a few messages in it.
@@ -1052,7 +1049,7 @@ class RecursiveRelationTestCase(BaseRelationsTestCase):
         channel = self.make_request(
             "GET",
             f"/_matrix/client/v1/rooms/{self.room}/relations/{self.parent_id}/{RelationTypes.ANNOTATION}"
-            "?dir=f&limit=20&org.matrix.msc3981.recurse=true",
+            "?dir=f&limit=20&recurse=true",
             access_token=self.user_token,
         )
         self.assertEqual(200, channel.code, channel.json_body)
@@ -1065,7 +1062,7 @@ class RecursiveRelationTestCase(BaseRelationsTestCase):
         channel = self.make_request(
             "GET",
             f"/_matrix/client/v1/rooms/{self.room}/relations/{self.parent_id}/{RelationTypes.ANNOTATION}/m.reaction"
-            "?dir=f&limit=20&org.matrix.msc3981.recurse=true",
+            "?dir=f&limit=20&recurse=true",
             access_token=self.user_token,
         )
         self.assertEqual(200, channel.code, channel.json_body)