Synapse 1.42.0rc1 (2021-09-01)

Server administrators are reminded to read the upgrade notes.

Features

Add support for MSC3231: Token authenticated registration. Users can be required to submit a token during registration to authenticate themselves. Contributed by Callum Brown. (#10142)
Add support for MSC3283: Expose enable_set_displayname in capabilities. (#10452)
Port the PresenceRouter module interface to the new generic interface. (#10524)
Add pagination to the spaces summary based on updates to MSC2946. (#10613, #10725)

Validate new m.room.power_levels events. Contributed by @aaronraimist. (#10232)
Display an error on User-Interactive Authentication fallback pages when authentication fails. Contributed by Callum Brown. (#10561)
Remove pushers when deleting an e-mail address from an account. Pushers for old unlinked emails will also be deleted. (#10581, #10734)
Reject Client-Server /keys/query requests which provide device_ids incorrectly. (#10593)
Rooms with unsupported room versions are no longer returned via /sync. (#10644)
Enforce the maximum length for per-room display names and avatar URLs. (#10654)
Fix a bug which caused the synapse_user_logins_total Prometheus metric not to be correctly initialised on restart. (#10677)
Improve ServerNoticeServlet to avoid duplicate requests and add unit tests. (#10679)
Fix long-standing issue which caused an error when a thumbnail is requested and there are multiple thumbnails with the same quality rating. (#10684)
Fix a regression introduced in v1.41.0 which affected the performance of concurrent fetches of large sets of events, in extreme cases causing the process to hang. (#10703)
Fix a regression introduced in Synapse 1.41 which broke email transmission on Systems using older versions of the Twisted library. (#10713)

Add documentation on how to connect Django with Synapse using OpenID Connect and django-oauth-toolkit. Contributed by @HugoDelval. (#10192)
Advertise https://matrix-org.github.io/synapse documentation in the README and CONTRIBUTING files. (#10595)
Fix some of the titles not rendering in the OpenID Connect documentation. (#10639)
Minor clarifications to the documentation for reverse proxies. (#10708)
Remove table of contents from the top of installation and contributing documentation pages. (#10711)

Improve type hints for the proxy agent and SRV resolver modules. Contributed by @dklimpel. (#10608)
Clean up some of the federation event authentication code for clarity. (#10614, #10615, #10624, #10640)
Add a comment asking developers to leave a reason when bumping the database schema version. (#10621)
Remove not needed database updates in modify user admin API. (#10627)
Convert room member storage tuples to attrs classes. (#10629, #10642)
Use auto-attribs for the attrs classes used in sync. (#10630)
Make backfill and get_missing_events use the same codepath. (#10645)
Improve the performance of the /hierarchy API (from MSC2946) by caching responses received over federation. (#10647)
Run a nightly CI build against Twisted trunk. (#10651, #10672)
Do not print out stack traces for network errors when fetching data over federation. (#10662)
Simplify tests for device admin rest API. (#10664)
Add missing type hints to REST servlets. (#10665, #10666, #10674)
Flatten the tests.synapse.rests package by moving the contents of v1 and v2_alpha into the parent. (#10667)
Update complement.sh to rebuild the base Docker image when run with workers. (#10686)
Split the event-processing methods in FederationHandler into a separate FederationEventHandler. (#10692)
Remove unused compare_digest function. (#10706)