This removes the configuration flag & updates the identifiers to
use the stable version.

This removes the configuration flag & updates the identifiers to
use the stable version.

Update intentional mentions (MSC3952) to depend on `exact_event_property_contains` (MSC3966). (#15051)

This replaces the specific `is_user_mention` push rule condition
used in MSC3952 with the generic `exact_event_property_contains`
push rule condition from MSC3966.

This replaces the specific `is_room_mention` push rule condition
used in MSC3952 with the generic `exact_event_match` push rule
condition from MSC3758.

No functionality changes due to this.

Co-authored-by: Brad Murray <brad@beeper.com>
Co-authored-by: Nick Barrett <nick@beeper.com>

Copy the suppress_edits push rule from Beeper to implement MSC3958.

https://github.com/beeper/synapse/blame/9415a1284b1bfb558bd66f28c24ca1611e6c6fa2/rust/src/push/base_rules.rs#L98-L114

If the feature is enabled and the event has a `m.mentions` property,
skip processing of the legacy mentions rules.

* Better test for bad values in power levels events

The previous test only checked that Synapse didn't raise an exception,
but didn't check that we had correctly interpreted the value of the
dodgy power level.

It also conflated two things: bad room notification levels, and bad user
levels. There _is_ logic for converting the latter to integers, but we
should test it separately.

* Check we ignore types that don't convert to int

* Handle `None` values in `notifications.room`

* Changelog

* Also test that bad values are rejected by event auth

* Docstring

* linter scripttttttttt

MSC3952 defines push rules which searches for mentions in a list of
Matrix IDs in the event body, instead of searching the entire event
body for display name / local part.

This is implemented behind an experimental configuration flag and
does not yet implement the backwards compatibility pieces of the MSC.

* Add initial option

* changelog

* Some more linting