Fallback if 'approved' isn't included in a registration replication request

changelog.d/14135.bugfix

@@ -0,0 +1 @@
+Fix a bug introduced in Synapse 1.69.0rc1 which would cause registration replication requests to fail if the worker sending the request is not running Synapse 1.69.

synapse/replication/http/register.py

@@ -39,6 +39,16 @@ def __init__(self, hs: "HomeServer"):
  self.store = hs.get_datastores().main
  self.registration_handler = hs.get_registration_handler()
 
+ # Default value if the worker that sent the replication request did not include
+ # an 'approved' property.
+ if (
+ hs.config.experimental.msc3866.enabled
+ and hs.config.experimental.msc3866.require_approval_for_new_accounts
+ ):
+ self._approval_default = False
+ else:
+ self._approval_default = True
+
  @staticmethod
  async def _serialize_payload( # type: ignore[override]
  user_id: str,
@@ -92,6 +102,12 @@ async def _handle_request( # type: ignore[override]
 
  await self.registration_handler.check_registration_ratelimit(content["address"])
 
+ # Always default admin users to approved (since it means they were created by
+ # an admin).
+ approved_default = self._approval_default
+ if content["admin"]:
+ approved_default = True
+
  await self.registration_handler.register_with_store(
  user_id=user_id,
  password_hash=content["password_hash"],
@@ -103,7 +119,7 @@ async def _handle_request( # type: ignore[override]
  user_type=content["user_type"],
  address=content["address"],
  shadow_banned=content["shadow_banned"],
- approved=content["approved"],
+ approved=content.get("approved", approved_default),
  )
 
  return 200, {}