Merge tag 'v1.56.0rc1' into develop

Synapse 1.56.0rc1 (2022-03-29)
==============================

Features
--------

- Allow modules to store already existing 3PID associations. ([\#12195](https://github.com/matrix-org/synapse/issues/12195))
- Allow registering server administrators using the module API. Contributed by Famedly. ([\#12250](https://github.com/matrix-org/synapse/issues/12250))

Bugfixes
--------

- Fix a long-standing bug which caused the `/_matrix/federation/v1/state` and `/_matrix/federation/v1/state_ids` endpoints to return incorrect or invalid data when called for an event which we have stored as an "outlier". ([\#12087](https://github.com/matrix-org/synapse/issues/12087))
- Fix a long-standing bug where events from ignored users would still be considered for relations. ([\#12227](https://github.com/matrix-org/synapse/issues/12227), [\#12232](https://github.com/matrix-org/synapse/issues/12232), [\#12285](https://github.com/matrix-org/synapse/issues/12285))
- Fix a bug introduced in Synapse 1.53.0 where an unnecessary query could be performed when fetching bundled aggregations for threads. ([\#12228](https://github.com/matrix-org/synapse/issues/12228))
- Fix a bug introduced in Synapse 1.52.0 where admins could not deactivate and GDPR-erase a user if Synapse was configured with limits on avatars. ([\#12261](https://github.com/matrix-org/synapse/issues/12261))

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

- Fix the link to the module documentation in the legacy spam checker warning message. ([\#12231](https://github.com/matrix-org/synapse/issues/12231))
- Remove incorrect prefixes in the worker documentation for some endpoints. ([\#12243](https://github.com/matrix-org/synapse/issues/12243))
- Correct `check_username_for_spam` annotations and docs. ([\#12246](https://github.com/matrix-org/synapse/issues/12246))
- Correct Authentik OpenID typo, and add notes on troubleshooting. Contributed by @IronTooch. ([\#12275](https://github.com/matrix-org/synapse/issues/12275))
- HAProxy reverse proxy guide update to stop sending IPv4-mapped address to homeserver. Contributed by @villepeh. ([\#12279](https://github.com/matrix-org/synapse/issues/12279))

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

- Rename `shared_rooms` to `mutual_rooms` ([MSC2666](https://github.com/matrix-org/matrix-doc/pull/2666)), as per proposal changes. ([\#12036](https://github.com/matrix-org/synapse/issues/12036))
- Remove check on `update_user_directory` for shared rooms handler ([MSC2666](https://github.com/matrix-org/matrix-doc/pull/2666)), and update/expand documentation. ([\#12038](https://github.com/matrix-org/synapse/issues/12038))
- Refactor `create_new_client_event` to use a new parameter, `state_event_ids`, which accurately describes the usage with [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) instead of abusing `auth_event_ids`. ([\#12083](https://github.com/matrix-org/synapse/issues/12083), [\#12304](https://github.com/matrix-org/synapse/issues/12304))
- Refuse to start if registration is enabled without email, captcha, or token-based verification unless the new config flag `enable_registration_without_verification` is set. ([\#12091](https://github.com/matrix-org/synapse/issues/12091))
- Add tests for database transaction callbacks. ([\#12198](https://github.com/matrix-org/synapse/issues/12198))
- Handle cancellation in `DatabasePool.runInteraction`. ([\#12199](https://github.com/matrix-org/synapse/issues/12199))
- Add missing type hints for cache storage. ([\#12216](https://github.com/matrix-org/synapse/issues/12216))
- Add missing type hints for storage. ([\#12248](https://github.com/matrix-org/synapse/issues/12248), [\#12255](https://github.com/matrix-org/synapse/issues/12255))
- Add type hints to tests files. ([\#12224](https://github.com/matrix-org/synapse/issues/12224), [\#12240](https://github.com/matrix-org/synapse/issues/12240), [\#12256](https://github.com/matrix-org/synapse/issues/12256))
- Use type stubs for `psycopg2`. ([\#12269](https://github.com/matrix-org/synapse/issues/12269))
- Improve type annotations for `execute_values`. ([\#12311](https://github.com/matrix-org/synapse/issues/12311))
- Clean-up logic around rebasing URLs for URL image previews. ([\#12219](https://github.com/matrix-org/synapse/issues/12219))
- Use the `ignored_users` table in additional places instead of re-parsing the account data. ([\#12225](https://github.com/matrix-org/synapse/issues/12225))
- Refactor the relations endpoints to add a `RelationsHandler`. ([\#12237](https://github.com/matrix-org/synapse/issues/12237))
- Generate announcement links in the release script. ([\#12242](https://github.com/matrix-org/synapse/issues/12242))
- Improve error message when dependencies check finds a broken installation. ([\#12244](https://github.com/matrix-org/synapse/issues/12244))
- Compress metrics HTTP resource when enabled. Contributed by Nick @ Beeper. ([\#12258](https://github.com/matrix-org/synapse/issues/12258))
- Refuse to start if the PostgreSQL database has a non-`C` locale, unless the config flag `allow_unsafe_db_locale` is set to true. ([\#12262](https://github.com/matrix-org/synapse/issues/12262), [\#12288](https://github.com/matrix-org/synapse/issues/12288))
- Optionally include account validity expiration information to experimental [MSC3720](https://github.com/matrix-org/matrix-doc/pull/3720) account status responses. ([\#12266](https://github.com/matrix-org/synapse/issues/12266))
- Add a new cache `_get_membership_from_event_id` to speed up push rule calculations in large rooms. ([\#12272](https://github.com/matrix-org/synapse/issues/12272))
- Re-enable Complement concurrency in CI. ([\#12283](https://github.com/matrix-org/synapse/issues/12283))
- Remove unused test utilities. ([\#12291](https://github.com/matrix-org/synapse/issues/12291))
- Enhance logging for inbound federation events. ([\#12301](https://github.com/matrix-org/synapse/issues/12301))
- Fix compatibility with the recently-released Jinja 3.1. ([\#12313](https://github.com/matrix-org/synapse/issues/12313))
- Avoid trying to calculate the state at outlier events. ([\#12314](https://github.com/matrix-org/synapse/issues/12314))

changelog.d/12036.misc

-Rename `shared_rooms` to `mutual_rooms` (MSC2666), as per proposal changes.
\ No newline at end of file

changelog.d/12038.misc

-Remove check on `update_user_directory` for shared rooms handler (MSC2666), and update/expand documentation.
\ No newline at end of file

changelog.d/12083.misc

-Refactor `create_new_client_event` to use a new parameter, `state_event_ids`, which accurately describes the usage with [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) instead of abusing `auth_event_ids`.

changelog.d/12087.bugfix

-Fix a long-standing bug which caused the `/_matrix/federation/v1/state` and `.../state_ids` endpoints to return incorrect or invalid data when called for an event which we have stored as an "outlier".

changelog.d/12091.misc

-Refuse to start if registration is enabled without email, captcha, or token-based verification unless new config flag `enable_registration_without_verification` is set.

changelog.d/12195.feature

-Allow modules to store already existing 3PID associations.

changelog.d/12198.misc

-Add tests for database transaction callbacks.

changelog.d/12199.misc

-Handle cancellation in `DatabasePool.runInteraction()`.

changelog.d/12216.misc

-Add missing type hints for cache storage.

changelog.d/12219.misc

-Clean-up logic around rebasing URLs for URL image previews.

changelog.d/12224.misc

-Add type hints to tests files.

changelog.d/12225.misc

-Use the `ignored_users` table in additional places instead of re-parsing the account data.

changelog.d/12227.bugfix

-Fix a long-standing bug where events from ignored users were still considered for relations.

changelog.d/12228.bugfix

-Fix a bug introduced in v1.53.0 where an unnecessary query could be performed when fetching bundled aggregations for threads.

changelog.d/12231.doc

-Fix the link to the module documentation in the legacy spam checker warning message.

changelog.d/12232.bugfix

-Fix a long-standing bug where events from ignored users were still considered for relations.

changelog.d/12237.misc

-Refactor the relations endpoints to add a `RelationsHandler`.

changelog.d/12240.misc

-Add type hints to tests files.
\ No newline at end of file