* Introduce `should_include_local_users_in_dir`

We exclude three kinds of local users from the user_directory tables. At
present we don't consistently exclude all three in the same places. This
commit introduces a new function to gather those exclusion conditions
together. Because we have to handle local and remote users in different
ways, I've made that function only consider the case of remote users.
It's the caller's responsibility to make the local versus remote
distinction clear and correct.

A test fixup is required. The test now hits a path which makes db
queries against the users table. The expected rows were missing, because
we were using a dummy user that hadn't actually been registered.

We also add new test cases to covert the exclusion logic.

----

By my reading this makes these changes:

* When an app service user registers or changes their profile, they will
  _not_ be added to the user directory. (Previously only support and
  deactivated users were excluded). This is consistent with the logic that
  rebuilds the user directory. See also [the discussion
  here](https://github.com/matrix-org/synapse/pull/10914#discussion_r716859548

).
* When rebuilding the directory, exclude support and disabled users from
  room sharing tables. Previously only appservice users were excluded.
* Exclude all three categories of local users when rebuilding the
  directory. Previously `_populate_user_directory_process_users` didn't do
  any exclusion.

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

This fixes a "Event not signed by authorising server" error when
transition room member from join -> join, e.g. when updating a
display name or avatar URL for restricted rooms.

* type-hint `HomeserverTestcase.setup_test_homeserver`

For better IDE completion. A small drive-by.

Uses `override_config` and fixes test_auto_create_auto_join_where_no_consent
to properly configure auto-join rooms.

This fixes a "Event not signed by authorising server" error when
transition room member from join -> join, e.g. when updating a
display name or avatar URL for restricted rooms.

Fix some harmless errors from background processes (mostly
due to awaiting Mock objects) that occurred in the Synapse
logs during unit tests.

This follows a correction made in twisted/twisted#1664 and should fix our Twisted Trial CI job.

Until that change is in a twisted release, we'll have to ignore the type
of the `host` argument. I've raised #10899 to remind us to review the
issue in a few months' time.

* Pull out GetUserDirectoryTables helper
* Don't rebuild the dir in tests that don't need it

In #10796 I changed registering a user to add directory entries under.
This means we don't have to force a directory regbuild in to tests of
the user directory search.

* Move test_initial to tests/storage
* Add type hints to both test_user_directory files

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

Broadly, the existing `event_auth.check` function has two parts:
 * a validation section: checks that the event isn't too big, that it has the rught signatures, etc. 
   This bit is independent of the rest of the state in the room, and so need only be done once 
   for each event.
 * an auth section: ensures that the event is allowed, given the rest of the state in the room.
   This gets done multiple times, against various sets of room state, because it forms part of
   the state res algorithm.

Currently, this is implemented with `do_sig_check` and `do_size_check` parameters, but I think
that makes everything hard to follow. Instead, we split the function in two and call each part
separately where it is needed.

* Inline `_check_event_auth` for outliers

When we are persisting an outlier, most of `_check_event_auth` is redundant:

 * `_update_auth_events_and_context_for_auth` does nothing, because the
   `input_auth_events` are (now) exactly the event's auth_events,
   which means that `missing_auth` is empty.

 * we don't care about soft-fail, kicking guest users or `send_on_behalf_of`
   for outliers

... so the only thing that matters is the auth itself, so let's just do that.

* `_auth_and_persist_fetched_events_inner`: de-async `prep`

`prep` no longer calls any `async` methods, so let's make it synchronous.

* Simplify `_check_event_auth`

We no longer need to support outliers here, which makes things rather simpler.

* changelog

* lint

URL cache files are short-lived and it does not make sense to offload
them (eg. to the cloud) or back them up.

This is in the context of creating new module callbacks that modules in https://github.com/matrix-org/synapse-dinsic can use, in an effort to reconcile the spam checker API in synapse-dinsic with the one in mainline.

This adds a callback that's fairly similar to user_may_create_room except it also allows processing based on the invites sent at room creation.

* Factor more stuff out of `_get_events_and_persist`

It turns out that the event-sorting algorithm in `_get_events_and_persist` is
also useful in other circumstances. Here we move the current
`_auth_and_persist_fetched_events` to `_auth_and_persist_fetched_events_inner`,
and then factor the sorting part out to `_auth_and_persist_fetched_events`.

* `_get_remote_auth_chain_for_event`: remove redundant `outlier` assignment

`get_event_auth` returns events with the outlier flag already set, so this is
redundant (though we need to update a test where `get_event_auth` is mocked).

* `_get_remote_auth_chain_for_event`: move existing-event tests earlier

Move a couple of tests outside the loop. This is a bit inefficient for now, but
a future commit will make it better. It should be functionally identical.

* `_get_remote_auth_chain_for_event`: use `_auth_and_persist_fetched_events`

We can use the same codepath for persisting the events fetched as part of an
auth chain as for those fetched individually by `_get_events_and_persist` for
building the state at a backwards extremity.

* `_get_remote_auth_chain_for_event`: use a dict for efficiency

`_auth_and_persist_fetched_events` sorts the events itself, so we no longer
need to care about maintaining the ordering from `get_event_auth` (and no
longer need to sort by depth in `get_event_auth`).

That means that we can use a map, making it easier to filter out events we
already have, etc.

* changelog

* `_auth_and_persist_fetched_events`: improve docstring

If the MAU count had been reached, Synapse incorrectly blocked appservice users even though they've been explicitly configured not to be tracked (the default). This was due to bypassing the relevant if as it was chained behind another earlier hit if as an elif.

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

* Improve typing in user_directory files

This makes the user_directory.py in storage pass most of mypy's
checks (including `no-untyped-defs`). Unfortunately that file is in the
tangled web of Store class inheritance so doesn't pass mypy at the moment.

The handlers directory has already been mypyed.

Co-authored-by: reivilibre <olivier@librepush.net>

Per updates to MSC3231 in order to use the same grammar
as other identifiers.

Co-authored-by: Dirk Klimpel <5740567+dklimpel@users.noreply.github.com>
Co-authored-by: reivilibre <olivier@librepush.net>
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

This avoids the overhead of searching through the various
configuration classes by directly referencing the class that
the attributes are in.

It also improves type hints since mypy can now resolve the
types of the configuration variables.

* add test to check if null code points are being inserted

* add logic to detect and replace null code points before insertion into db

* lints

* add license to test

* change approach to null substitution

* add type hint for SearchEntry

* Add changelog entry

Signed-off-by: H.Shay <shaysquared@gmail.com>

* updated changelog

* update chanelog message

* remove duplicate changelog

* Update synapse/storage/databases/main/events.py remove extra space

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

* rename and move test file, update tests, delete old test file

* fix typo in comments

* update _find_highlights_in_postgres to replace null byte with space

* replace null byte in sqlite search insertion

* beef up and reorganize test for this pr

* update changelog

* add type hints and update docstring

* check db engine directly vs using env variable

* refactor tests to be less repetetive

* move rplace logic into seperate function

* requested changes

* Fix typo.

* Update synapse/storage/databases/main/search.py

Co-authored-by: reivilibre <olivier@librepush.net>

* Update changelog.d/10820.misc

Co-authored-by: Aaron Raimist <aaron@raim.ist>

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>
Co-authored-by: reivilibre <olivier@librepush.net>
Co-authored-by: Aaron Raimist <aaron@raim.ist>

* Improved titles (fall back to the author name if there's not title) and include the site name.
* Handle photo/video payloads.
* Include the original URL in the Open Graph response.
* Fix the expiration time (by properly converting from seconds to milliseconds).

Extend ModuleApi with the methods we'll need to reject spam based on IP - resolves #10832

Signed-off-by: David Teller <davidt@element.io>

The major change is moving the decision of whether to use oEmbed
further up the call-stack. This reverts the _download_url method to
being a "dumb" functionwhich takes a single URL and downloads it
(as it was before #7920).

This also makes more minor refactorings:

* Renames internal variables for clarity.
* Factors out shared code between the HTML and rich oEmbed
  previews.
* Fixes tests to preview an oEmbed image.

Test for #10830

Ideally the test would also make sure the new state event comes down sync, but this is probably good enough.

* add tests for checking if room search works with non-ascii char

* change encoding on parse_string to UTF-8

* lints

* properly encode search term

* lints

* add changelog file

* update changelog number

* set changelog entry filetype to .bugfix

* Revert "set changelog entry filetype to .bugfix"

This reverts commit be8e5a314251438ec4ec7dbc59ba32162c93e550.

* update changelog message and file type

* change parse_string default encoding back to ascii and update room search admin api calll to parse string

* refactor tests

* Update tests/rest/admin/test_room.py

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

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

It's a simplification, but one that'll help make the user directory logic easier
to follow with the other changes upcoming. It's not strictly required for those
changes, but this will help simplify the resulting logic that listens for
`m.room.member` events and generally make the logic easier to follow.

This means the config option `search_all_users` ends up controlling the
search query only, and not the data we store. The cost of doing so is an
extra row in the `user_directory` and `user_directory_search` tables for
each local user which

- belongs to no public rooms
- belongs to no private rooms of size ≥ 2

I think the cost of this will be marginal (since they'll already have entries
 in `users` and `profiles` anyway).

As a small upside, a homeserver whose directory was built with this
change can toggle `search_all_users` without having to rebuild their
directory.

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

* Allow membership event to unban user

Signed-off-by: Aaron Raimist <aaron@raim.ist>

To avoid duplicating it between a few tests.

Also enables Mypy for related tests.

Instead of proxying through the magic getter of the RootConfig
object. This should be more performant (and is more explicit).

By copying the `room_type` field of the create event and
migrating any non-empty `m.space.child` events to the
new room that is created.