R30v2 has been out since 2021-07-19 (https://github.com/matrix-org/synapse/pull/10332)
and we started collecting stats on 2021-08-16. Since it's been over a year now
(almost 2 years), this is enough grace period for us to now rip it out.

Avoid renaming configuration settings for now and rename internal code
to use blocklist and allowlist instead.

To improve the organization of this code it moves the JWT login
checks to a separate handler and then fixes the bug (and a
deprecation warning).

Synapse will no longer send (or respond to) the unstable flags
for faster joins. These were only available behind a configuration
flag and handled in parallel with the stable flags.

This change fixes two memory leaks during `trial` test runs.

Garbage collection is disabled during each test case and a gen-0 GC is
run at the end of each test. However, when the gen-0 GC is run, the
`TestCase` object usually still holds references to the `HomeServer`
used during the test. As a result, the `HomeServer` gets promoted to
gen-1 and then never garbage collected.

Fix this by periodically running full GCs.

Additionally, fix `HomeServer`s leaking after tests that touch inbound
federation due to `FederationRateLimiter`s adding themselves to a global
set, by turning the set into a `WeakSet`.

Resolves #15622.

Signed-off-by: Sean Quah <seanq@matrix.org>

If the previous read marker is pointing to an event that no longer exists
(e.g. due to retention) then assume that the newly given read marker
is newer.

To track changes in MSC2666:

- The change from `/mutual_rooms/{user_id}` to `/mutual_rooms?user_id={user_id}`.
- The addition of `next_batch_token` (and logic).
- Unstable flag now being `uk.half-shot.msc2666.query_mutual_rooms`.
- The error code when your own user is requested.

Do an `apt update` before install packages.

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

Part of #14809.

Signed-off-by: Sean Quah <seanq@matrix.org>

The second argument of `ConfigError` is a path, passed as an optional
`Iterable[str]` and not a `str`. If a string is passed directly,
Synapse unhelpfully emits "Error in configuration at
a.p.p._.s.e.r.v.i.c.e._.c.o.n.f.i.g._.f.i.l.e.s'" when the config
option has the wrong data type.

Signed-off-by: Sean Quah <seanq@matrix.org>

This allows an external service (e.g. the matrix-authentication-service)
to create devices for users.

There are two situations which were previously not properly checked:

1. If the requested URL was replaced with an oEmbed URL, then the
   oEmbed URL was not checked against url_preview_url_blacklist.
2. Follow-up URLs (either via autodiscovery of oEmbed or to pre-cache
   images) were not checked against url_preview_url_blacklist.

A bunch of comments and variables are out of date and use
obsolete terms.

We use the oldest Python version because later Python versions can include some overloads which don't work in the older versions which we still support.

We're using Python 3.8 instead of 3.7 which is our actual minimum support version because it's EOL is in a matter of weeks so can avoid the extra effort. And in any case, minimum Python 3.8 support is better than winging it on Python 3.11.

* Usage that is compatible with Python 3.8 and 3.11

> Since Python 3.10, instead of passing value and tb, an exception object can
  be passed as the first argument. If value and tb are provided, the first
  argument is ignored in order to provide backwards compatibility.
>
> -- https://docs.python.org/3/library/traceback.html

* Add changelog

Fix the following `mypy` errors when running `mypy` with Python 3.7:
```
synapse/storage/controllers/stats.py:58: error: "Counter" is not subscriptable, use "typing.Counter" instead  [misc]

tests/test_state.py:267: error: "dict" is not subscriptable, use "typing.Dict" instead  [misc]
```

Part of https://github.com/matrix-org/synapse/issues/15603

In Python 3.9, `typing` is deprecated and the types are subscriptable (generics) by default, https://peps.python.org/pep-0585/#implementation

This reverts commit 55b08534.

Fix:
```
tests/test_state.py:267: error: "dict" is not subscriptable, use "typing.Dict" instead  [misc]
```

In Python 3.9, `typing` is deprecated and the types are subscriptable (generics) by default,
https://peps.python.org/pep-0585/#implementation

Updates the redaction rules to protect enough information that the
event can still be properly verified.

Instead of resulting in an internal server error for invalid events,
return that the event is invalid.

MSC3389 proposes protecting the relation type & parent event ID
from redaction. This keeps the relation information intact after
redaction which helps with some UX flaws (e.g. deleting an
event causes it to no longer be in a thread, which is confusing).

This reverts commit 34ab8013.

Signed-off-by: Michael Weimann <michaelw@matrix.org>
Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

Adds logging for key server requests which include a key ID.
This is technically in violation of the 1.6 spec, but is the only
way to remain backwards compatibly with earlier versions of
Synapse (and possibly other homeservers) which *did* include
the key ID.

Revert "Set thread_id column to non-null for event_push_{actions,actions_staging,summary} (#15437)" (#15580)

This reverts commit a7b3e9ce.

See https://github.com/matrix-org/synapse/pull/15566#issuecomment-1543844104

Also check you can `pip install` in the old-deps CI job