Upstream have merged our changes
(https://github.com/spotify/dh-virtualenv/pull/300), so let's switch back to it
instead of using our fork.

* Expose `return_html_error`, and allow it to take a Jinja2 template instead of a raw string

* Clean up exception handling in SAML2ResponseResource

  * use the existing code in `return_html_error` instead of re-implementing it
    (giving it a jinja2 template rather than inventing a new form of template)

  * do the exception-catching in the REST layer rather than in the handler
    layer, to make sure we catch all exceptions.

Just in case people head straight to the troubleshooting section and find themselves at a dead end.

Synapse supports Python 3.8. We've been using it in CI for a while now.

It looks like `user_device_resync` was ignoring cross-signing keys from the results received from the remote server. This patch fixes this, by processing these keys using the same process `_handle_signing_key_updates` does (and effectively factor that part out of that function).

The query keeps showing up in my slow query log.

This changes the plan under the top-level Sort node from

```
    WindowAgg  (cost=280335.88..292963.15 rows=561212 width=80) (actual time=138.651..160.562 rows=27112 loops=1)
      ->  Sort  (cost=280335.88..281738.91 rows=561212 width=84) (actual time=138.597..140.622 rows=27112 loops=1)
            Sort Key: state_groups_state.type, state_groups_state.state_key, state_groups_state.state_group
            Sort Method: quicksort  Memory: 4581kB
            ->  Nested Loop  (cost=2.83..226745.22 rows=561212 width=84) (actual time=21.548..47.657 rows=27112 loops=1)
                  ->  HashAggregate  (cost=2.27..3.28 rows=101 width=8) (actual time=21.526..21.535 rows=20 loops=1)
                        Group Key: state.state_group
                        ->  CTE Scan on state  (cost=0.00..2.02 rows=101 width=8) (actual time=21.280..21.493 rows=20 loops=1)
                  ->  Index Scan using state_groups_state_type_idx on state_groups_state  (cost=0.56..2189.40 rows=5557 width=84) (actual time=0.005..0.991 rows=1356 loops=20)
                        Index Cond: (state_group = state.state_group)
```

to

```
    Nested Loop  (cost=2.83..226745.22 rows=561212 width=84) (actual time=24.194..52.834 rows=27112 loops=1)
      ->  HashAggregate  (cost=2.27..3.28 rows=101 width=8) (actual time=24.130..24.138 rows=20 loops=1)
            Group Key: state.state_group
            ->  CTE Scan on state  (cost=0.00..2.02 rows=101 width=8) (actual time=23.887..24.113 rows=20 loops=1)
      ->  Index Scan using state_groups_state_type_idx on state_groups_state  (cost=0.56..2189.40 rows=5557 width=84) (actual time=0.016..1.159 rows=1356 loops=20)
            Index Cond: (state_group = state.state_group)
```

This cuts the execution time from ~190ms to ~130ms, i.e. a reduction
of ~30%.

The full plans are visualised at https://explain.depesz.com/s/WpbT and
https://explain.depesz.com/s/KlEk



Signed-off-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>

Without this patch, if an error happens which isn't caught by `user_device_resync`, then `_maybe_retry_device_resync` would fail, without retrying the next users in the iteration. This patch fixes this so that it now only logs an error in this case.

Fixes #7469

Signed-off-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>

Synapse was added to the ports tree in Nov, 2019 by Renaud Allard (https://marc.info/?l=openbsd-ports&m=157417848805329).
With the release of OpenBSD 6.7 on May 22, 2020 a pre-compiled binary is available as well.

Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

Speed up processing of federation stream RDATA rows.

Instead of storing and sending an ACK for every single row we send
synchronously, we instead do it asynchronously while batching up
updates.

Signed-off-by: Christopher Cooper <cooperc@ocf.berkeley.edu>

Synapse 1.14.0rc2 (2020-05-27)
==============================

Bugfixes
--------

- Fix cache config to not apply cache factor to event cache. Regression in v1.14.0rc1. ([\#7578](https://github.com/matrix-org/synapse/issues/7578))
- Fix bug where `ReplicationStreamer` was not always started when replication was enabled. Bug introduced in v1.14.0rc1. ([\#7579](https://github.com/matrix-org/synapse/issues/7579))
- Fix specifying individual cache factors for caches with special characters in their name. Regression in v1.14.0rc1. ([\#7580](https://github.com/matrix-org/synapse/issues/7580))

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

- Fix the OIDC `client_auth_method` value in the sample config. ([\#7581](https://github.com/matrix-org/synapse/issues/7581))

We were using `logger` syntax which isn't supported by `Exception`s.

'client_auth_method' commented out value was erronously 'client_auth_basic',
when code and docstring says it should be 'client_secret_basic'.

Signed-off-by: Jason Robinson <jasonr@matrix.org>

This mostly applise to `*stateGroupCache*` and co.

Broke in #6391.

This is already correctly done when we instansiate the cache, but wasn't
when it got reloaded (which always happens at least once on startup).

Fixes #7566.

Since this is not a full release yet