Do not return unspecced original_event field when using the stable /relations endpoint. (#14025)

Keep the old behavior (of including the original_event field) for any
requests to the /unstable version of the endpoint, but do not include
the field when the /v1 version is used.

This should avoid new clients from depending on this field, but will
not help with current dependencies.

1 files changed, 6 insertions, 0 deletions

diff --git a/synapse/rest/client/relations.py b/synapse/rest/client/relations.py

index 205c556f64..7a25de5c85 100644
--- a/synapse/rest/client/relations.py
+++ b/synapse/rest/client/relations.py
@@ -82,6 +82,11 @@ class RelationPaginationServlet(RestServlet):
         if to_token_str:
             to_token = await StreamToken.from_string(self.store, to_token_str)
 
+        # The unstable version of this API returns an extra field for client
+        # compatibility, see https://github.com/matrix-org/synapse/issues/12930.
+        assert request.path is not None
+        include_original_event = request.path.startswith(b"/_matrix/client/unstable/")
+
         result = await self._relations_handler.get_relations(
             requester=requester,
             event_id=parent_id,
@@ -92,6 +97,7 @@ class RelationPaginationServlet(RestServlet):
             direction=direction,
             from_token=from_token,
             to_token=to_token,
+            include_original_event=include_original_event,
         )
 
         return 200, result