This is a small bug that I noticed while working on #8956.
We have a for-loop which attempts to strip all presence changes for each user except for the final one, as we don't really care about older presence:
9e19c6aab4/synapse/handlers/presence.py (L368-L371)
`new_states_dict` stores this stripped copy of latest presence state for each user, before it is... put into a new variable `new_state`, which is just overridden by the subsequent for loop.
I believe this was instead meant to override `new_states`. Without doing so, it effectively meant:
1. The for loop had no effect.
2. We were still processing old presence state for users.
- Update black version to the latest
- Run black auto formatting over the codebase
- Run autoformatting according to [`docs/code_style.md
`](80d6dc9783/docs/code_style.md)
- Update `code_style.md` docs around installing black to use the correct version
==============================
Features
--------
- Further improvements to the user experience of registration via single sign-on. ([\#9297](https://github.com/matrix-org/synapse/issues/9297))
Bugfixes
--------
- Fix ratelimiting introduced in v1.27.0rc1 for invites to respect the `ratelimit` flag on application services. ([\#9302](https://github.com/matrix-org/synapse/issues/9302))
- Do not automatically calculate `public_baseurl` since it can be wrong in some situations. Reverts behaviour introduced in v1.26.0. ([\#9313](https://github.com/matrix-org/synapse/issues/9313))
Improved Documentation
----------------------
- Clarify the sample configuration for changes made to the template loading code. ([\#9310](https://github.com/matrix-org/synapse/issues/9310))
-----BEGIN PGP SIGNATURE-----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=NSyp
-----END PGP SIGNATURE-----
Merge tag 'v1.27.0rc2' into develop
Synapse 1.27.0rc2 (2021-02-11)
==============================
Features
--------
- Further improvements to the user experience of registration via single sign-on. ([\#9297](https://github.com/matrix-org/synapse/issues/9297))
Bugfixes
--------
- Fix ratelimiting introduced in v1.27.0rc1 for invites to respect the `ratelimit` flag on application services. ([\#9302](https://github.com/matrix-org/synapse/issues/9302))
- Do not automatically calculate `public_baseurl` since it can be wrong in some situations. Reverts behaviour introduced in v1.26.0. ([\#9313](https://github.com/matrix-org/synapse/issues/9313))
Improved Documentation
----------------------
- Clarify the sample configuration for changes made to the template loading code. ([\#9310](https://github.com/matrix-org/synapse/issues/9310))
Remove conflicting sqlite tables that throw sqlite3.OperationalError: object name reserved for internal use: event_search_content when running the twisted unit tests.
Fix#8996
Fixes some exceptions if the room state isn't quite as expected.
If the expected state events aren't found, try to find them in the
historical room state. If they still aren't found, fallback to a reasonable,
although ugly, value.
David Vo