Synapse 1.38.0rc1 (2021-07-06)
==============================

This release includes a database schema update which could result in elevated disk usage. See the [upgrade notes](https://matrix-org.github.io/synapse/develop/upgrade#upgrading-to-v1380) for more information.

Features
--------

- Implement refresh tokens as specified by [MSC2918](https://github.com/matrix-org/matrix-doc/pull/2918). ([\#9450](https://github.com/matrix-org/synapse/issues/9450))
- Add support for evicting cache entries based on last access time. ([\#10205](https://github.com/matrix-org/synapse/issues/10205))
- Omit empty fields from the `/sync` response. Contributed by @deepbluev7. ([\#10214](https://github.com/matrix-org/synapse/issues/10214))
- Improve validation on federation `send_{join,leave,knock}` endpoints. ([\#10225](https://github.com/matrix-org/synapse/issues/10225), [\#10243](https://github.com/matrix-org/synapse/issues/10243))
- Add SSO `external_ids` to the Query User Account admin API. ([\#10261](https://github.com/matrix-org/synapse/issues/10261))
- Mark events received over federation which fail a spam check as "soft-failed". ([\#10263](https://github.com/matrix-org/synapse/issues/10263))
- Add metrics for new inbound federation staging area. ([\#10284](https://github.com/matrix-org/synapse/issues/10284))
- Add script to print information about recently registered users. ([\#10290](https://github.com/matrix-org/synapse/issues/10290))

Bugfixes
--------

- Fix a long-standing bug which meant that invite rejections and knocks were not sent out over federation in a timely manner. ([\#10223](https://github.com/matrix-org/synapse/issues/10223))
- Fix a bug introduced in v1.26.0 where only users who have set profile information could be deactivated with erasure enabled. ([\#10252](https://github.com/matrix-org/synapse/issues/10252))
- Fix a long-standing bug where Synapse would return errors after 2<sup>31</sup> events were handled by the server. ([\#10264](https://github.com/matrix-org/synapse/issues/10264), [\#10267](https://github.com/matrix-org/synapse/issues/10267), [\#10282](https://github.com/matrix-org/synapse/issues/10282), [\#10286](https://github.com/matrix-org/synapse/issues/10286), [\#10291](https://github.com/matrix-org/synapse/issues/10291), [\#10314](https://github.com/matrix-org/synapse/issues/10314), [\#10326](https://github.com/matrix-org/synapse/issues/10326))
- Fix the prometheus `synapse_federation_server_pdu_process_time` metric. Broke in v1.37.1. ([\#10279](https://github.com/matrix-org/synapse/issues/10279))
- Ensure that inbound events from federation that were being processed when Synapse was restarted get promptly processed on start up. ([\#10303](https://github.com/matrix-org/synapse/issues/10303))

Improved Documentation
----------------------

- Move the upgrade notes to [docs/upgrade.md](https://github.com/matrix-org/synapse/blob/develop/docs/upgrade.md) and convert them to markdown. ([\#10166](https://github.com/matrix-org/synapse/issues/10166))
- Choose Welcome & Overview as the default page for synapse documentation website. ([\#10242](https://github.com/matrix-org/synapse/issues/10242))
- Adjust the URL in the README.rst file to point to irc.libera.chat. ([\#10258](https://github.com/matrix-org/synapse/issues/10258))
- Fix homeserver config option name in presence router documentation. ([\#10288](https://github.com/matrix-org/synapse/issues/10288))
- Fix link pointing at the wrong section in the modules documentation page. ([\#10302](https://github.com/matrix-org/synapse/issues/10302))

Internal Changes
----------------

- Drop `Origin` and `Accept` from the value of the `Access-Control-Allow-Headers` response header. ([\#10114](https://github.com/matrix-org/synapse/issues/10114))
- Add type hints to the federation servlets. ([\#10213](https://github.com/matrix-org/synapse/issues/10213))
- Improve the reliability of auto-joining remote rooms. ([\#10237](https://github.com/matrix-org/synapse/issues/10237))
- Update the release script to use the semver terminology and determine the release branch based on the next version. ([\#10239](https://github.com/matrix-org/synapse/issues/10239))
- Fix type hints for computing auth events. ([\#10253](https://github.com/matrix-org/synapse/issues/10253))
- Improve the performance of the spaces summary endpoint by only recursing into spaces (and not rooms in general). ([\#10256](https://github.com/matrix-org/synapse/issues/10256))
- Move event authentication methods from `Auth` to `EventAuthHandler`. ([\#10268](https://github.com/matrix-org/synapse/issues/10268))
- Re-enable a SyTest after it has been fixed. ([\#10292](https://github.com/matrix-org/synapse/issues/10292))

Fixes #10325

We might have events in the staging area if the service was restarted while there were unhandled events in the staging area.

Fixes #10295

Fix link in modules doc to point at instructions on registering a callback instead of ones on registering a web resource.

Instead of mixing them with user authentication methods.

this was a typo introduced in #10282. We don't want to end up doing the
`replace_stream_ordering_column` update after anything that comes up in
migration 60/03.

Now that we've fixed it.

Related to #10251

The presence router docs include some sample homeserver config. At some point we changed the name of the [config option](https://github.com/matrix-org/synapse/blob/859dc05b3692a3672c1a0db8deaaa9274b6aa6f5/docs/sample_config.yaml#L104-L113), but forgot to update the docs.

I've also added `presence.enabled: true` to the example, as that's the new way to enable presence (the `presence_enabled` option has been deprecated).

We need to rebuild *all* of the indexes that use the current `stream_ordering`
column.

This broke in #10272

Fixes #9490

This will break a couple of SyTest that are expecting failures to be added to the response of a federation /send, which obviously doesn't happen now that things are asynchronous.

Two drawbacks:

    Currently there is no logic to handle any events left in the staging area after restart, and so they'll only be handled on the next incoming event in that room. That can be fixed separately.
    We now only process one event per room at a time. This can be fixed up further down the line.

This adds a simple best effort locking mechanism that works cross workers.

Previously m.child.room events in non-space rooms would be
treated as part of the room graph, but this is no longer
supported.