I've now seen several people point at synapse#5133 and say "federation is broken in synapse 0.99.2".
I would never want to discourage people from upgrading, since each release usually comes with a raft of general bug fixes and performance improvements. However, there seems to be a lot of confusion around this point, so I'd like to clear some things up.
The confusion appears to arise from Synapse's implementation of the /_matrix/federation/v1/send/{txnId} federation REST endpoint. Up to, and including, Synapse 0.99.2, this was implemented in a way that was not compliant with the Matrix spec - in particular, it added a trailing slash to the URI (thus making it /_matrix/federation/v1/send/{txnId}/
) to outbound requests, and required that trailing slash on inbound requests.
This was fixed in Synapse 0.99.3 by:
- Accepting inbound requests without the trailing