Application services providing a "user" property (instead of "username") for
the /register endpoint was never specified. Deprecate this very old
fallback.

Speed up background jobs populate_full_user_id_user_filters and populate_full_user_id_profiles (#15700)

Fix a performance issue introduced in Synapse v1.83.0 which meant that purging rooms was very slow and database-intensive. (#15693)

* Add indices required to efficiently validate new foreign key constraints on stream_ordering

* Newsfile

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

---------

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

* Ditch dependabot changelog workflow

* Summarise dependabot commits in release script

* Changelog

* Update scripts-dev/release.py

* Bump types-bleach from 6.0.0.1 to 6.0.0.3

Bumps [types-bleach](https://github.com/python/typeshed) from 6.0.0.1 to 6.0.0.3.
- [Commits](https://github.com/python/typeshed/commits

)

---
updated-dependencies:
- dependency-name: types-bleach
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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* Changelog

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Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>
Co-authored-by: David Robertson <davidr@element.io>

* Bump types-requests from 2.30.0.0 to 2.31.0.0

Bumps [types-requests](https://github.com/python/typeshed) from 2.30.0.0 to 2.31.0.0.
- [Commits](https://github.com/python/typeshed/commits

)

---
updated-dependencies:
- dependency-name: types-requests
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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* Changelog

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
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Adds a new configuration setting to connect to Redis via a Unix
socket instead of over TCP. Disabled by default.

Fix #15667

 - Reiterate the importance of getting Rust installed and set up before attempting to install the Python dependencies.
 - Mention the importance of confirming that `poetry install` completed successfully and include a typical error that the user might see if it did not.
 - Expand on "Now edit homeserver.yaml" to give examples of things likely to need changing and to link to the relevant sections of the Synapse server documentation.

Updates the database schema to require a thread_id (by adding a
constraint that the column is non-null) for event_push_actions,
event_push_actions_staging, and event_push_actions_summary.

For PostgreSQL we add the constraint as NOT VALID, then
VALIDATE the constraint a background job to avoid locking
the table during an upgrade.

Each table is updated as a separate schema delta to avoid
deadlocks between them.

For SQLite we simply rebuild the table & copy the data.

Fix a bug introduced in Synapse v1.84.0 where workers do not start up when no `instance_map` was provided. (#15672)

* Fix #15669: always populate instance map even if it was empty

* Fix some tests

* Fix more tests

* Newsfile

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

* CI fix: don't forget to update apt repository sources before installing olddeps deps

* Add test testing the backwards compatibility

---------

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

Add `dch` and `notify-send` to the development Nix flake so that the release script can be used. (#15673)

* Add dch and notify-send to the Nix dev flake

* Newsfile

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

---------

Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>

Process previously failed backfill events in the background because they are bound to fail again and we don't need to waste time holding up the request for something that is bound to fail again.

Fix https://github.com/matrix-org/synapse/issues/13623

Follow-up to https://github.com/matrix-org/synapse/issues/13621 and https://github.com/matrix-org/synapse/issues/13622

Part of making `/messages` faster: https://github.com/matrix-org/synapse/issues/13356

Require type hints in test_descriptors and add missing ones.

The cached decorators always return a Deferred, which was not
properly propagated. It was close enough when wrapping coroutines,
but failed if a bare function was wrapped.

```
2023-05-21 09:30:09,288 - synapse.logging.opentracing - 940 - ERROR - POST-1 - @trace may not have wrapped StateStorageController.get_state_for_groups correctly! The function is not async but returned a coroutine
```

Tracing instrumentation for these functions originally introduced in https://github.com/matrix-org/synapse/pull/15610

This moves the deactivated user check to the method which
all login types call.

Additionally updates the application service tests to be more
realistic by removing invalid tests and fixing server names.

All the information needed is already in the `instance_map`, so
use that instead of passing the hostname / IP & port manually
for each replication request.

This consolidates logic for future improvements of using e.g.
UNIX sockets for workers.