Fixes redirect loop

Signed-off-by: Paul Tötterman <paul.totterman@iki.fi>

On NixOS, `bash` isn't under `/bin/bash` but rather in some directory in `$PATH`. Locally, I've been patching those scripts to make them work.

`/usr/bin/env` seems to be the only [portable way](https://unix.stackexchange.com/questions/29608/why-is-it-better-to-use-usr-bin-env-name-instead-of-path-to-name-as-my

) to use binaries from the PATH as interpreters.

Signed-off-by: Quentin Gliech <quentingliech@gmail.com>

Make it clearer in the source install step that the platform specific
prerequisites must be installed first.

Signed-off-by: Serban Constantin <serban.constantin@gmail.com>

Split off from https://github.com/matrix-org/synapse/pull/9491

Adds a storage method for getting the current presence of all local users, optionally excluding those that are offline. This will be used by the code in #9491 when a PresenceRouter module informs Synapse that a given user should have `"ALL"` user presence updates routed to them. Specifically, it is used here: https://github.com/matrix-org/synapse/blob/b588f16e391d664b11f43257eabf70663f0c6d59/synapse/handlers/presence.py#L1131-L1133

Note that there is a `get_all_presence_updates` function just above. That function is intended to walk up the table through stream IDs, and is primarily used by the presence replication stream. I could possibly make use of it in the PresenceRouter-related code, but it would be a bit of a bodge.

Broke in #9640

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

When we hit an unknown room in the space tree, see if there are other servers that we might be able to poll to get the data.

Fixes: #9447

This fixes an error ("Cannot determine consistent method resolution order (MRO)")
when running mypy with a cache.

It's legitimate behaviour to try and join a bunch of rooms at once.

Builds on the work done in #9643 to add a federation API for space summaries.

There's a bit of refactoring of the existing client-server code first, to avoid too much duplication.

Addresses https://github.com/matrix-org/synapse-dinsic/issues/70

This PR causes `ProxyAgent` to attempt to extract credentials from an `HTTPS_PROXY` env var. If credentials are found, a `Proxy-Authorization` header ([details](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Proxy-Authorization)) is sent to the proxy server to authenticate against it. The headers are *not* passed to the remote server.

Also added some type hints.

Cf. https://github.com/opencontainers/image-spec/blob/master/annotations.md#pre-defined-annotation-keys



Signed-off-by: Johannes Wienke <languitar@semipol.de>

- Merge 'isinstance' calls.
- Remove unnecessary dict call outside of comprehension.
- Use 'sys.exit()' calls.

Implement MSC3026: busy presence state

This is very bare-bones for now: federation will come soon, while pagination is descoped for now but will come later.

Currently federation catchup will send the last *local* event that we
failed to send to the remote. This can cause issues for large rooms
where lots of servers have sent events while the remote server was down,
as when it comes back up again it'll be flooded with events from various
points in the DAG.

Instead, let's make it so that all the servers send the most recent
events, even if its not theirs. The remote should deduplicate the
events, so there shouldn't be much overhead in doing this.
Alternatively, the servers could only send local events if they were
also extremities and hope that the other server will send the event
over, but that is a bit risky.

This bug was discovered by DINUM. We were modifying `serialized_event["content"]`, which - if you've got `USE_FROZEN_DICTS` turned on or are [using a third party rules module](https://github.com/matrix-org/synapse/blob/17cd48fe5171d50da4cb59db647b993168e7dfab/synapse/events/third_party_rules.py#L73-L76) - will raise a 500 if you try to a edit a reply to a message.

`serialized_event["content"]` could be set to the edit event's content, instead of a copy of it, which is bad as we attempt to modify it. Instead, we also end up modifying the original event's content. DINUM uses a third party rules module, which meant the event's content got frozen and thus an exception was raised.

To be clear, the problem is not that the event's content was frozen. In fact doing so helped us uncover the fact we weren't copying event content correctly.