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))
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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.
