Remove experimental MSC2716 implementation to incrementally import history into existing rooms (#15748)

Context for why we're removing the implementation:

 - https://github.com/matrix-org/matrix-spec-proposals/pull/2716#issuecomment-1487441010
 - https://github.com/matrix-org/matrix-spec-proposals/pull/2716#issuecomment-1504262734

Anyone wanting to continue MSC2716, should also address these leftover tasks: https://github.com/matrix-org/synapse/issues/10737

Closes https://github.com/matrix-org/synapse/issues/10737 in the fact that it is not longer necessary to track those things.

1 files changed, 0 insertions, 40 deletions

diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index b4b43ec4d7..3aaf53dfbd 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -339,13 +339,6 @@ def check_state_dependent_auth_rules(
     if event.type == EventTypes.Redaction:
         check_redaction(event.room_version, event, auth_dict)
 
-    if (
-        event.type == EventTypes.MSC2716_INSERTION
-        or event.type == EventTypes.MSC2716_BATCH
-        or event.type == EventTypes.MSC2716_MARKER
-    ):
-        check_historical(event.room_version, event, auth_dict)
-
     logger.debug("Allowing! %s", event)
 
 
@@ -365,7 +358,6 @@ LENIENT_EVENT_BYTE_LIMITS_ROOM_VERSIONS = {
     RoomVersions.V9,
     RoomVersions.MSC3787,
     RoomVersions.V10,
-    RoomVersions.MSC2716v4,
     RoomVersions.MSC1767v10,
 }
 
@@ -823,38 +815,6 @@ def check_redaction(
     raise AuthError(403, "You don't have permission to redact events")
 
 
-def check_historical(
-    room_version_obj: RoomVersion,
-    event: "EventBase",
-    auth_events: StateMap["EventBase"],
-) -> None:
-    """Check whether the event sender is allowed to send historical related
-    events like "insertion", "batch", and "marker".
-
-    Returns:
-        None
-
-    Raises:
-        AuthError if the event sender is not allowed to send historical related events
-        ("insertion", "batch", and "marker").
-    """
-    # Ignore the auth checks in room versions that do not support historical
-    # events
-    if not room_version_obj.msc2716_historical:
-        return
-
-    user_level = get_user_power_level(event.user_id, auth_events)
-
-    historical_level = get_named_level(auth_events, "historical", 100)
-
-    if user_level < historical_level:
-        raise UnstableSpecAuthError(
-            403,
-            'You don\'t have permission to send send historical related events ("insertion", "batch", and "marker")',
-            errcode=Codes.INSUFFICIENT_POWER,
-        )
-
-
 def _check_power_levels(
     room_version_obj: RoomVersion,
     event: "EventBase",