Paul Chobert d4de2ae1c5 Fix state_after for left rooms including post-leave lazy-loaded memberships (#20169) ...

## The bug

With the experimental
[MSC4222](https://github.com/matrix-org/matrix-spec-proposals/pull/4222)
implementation enabled (`use_state_after`) and lazy-loading of room
members, an incremental `/sync` could disclose state from **after** the
user's leave in a left room's `state_after`.

1. Alice syncs with `lazy_load_members: true` and
`use_state_after=true`.
2. Bob sends a message in a room they share.
3. Alice leaves the room.
4. Bob updates his per-room displayname
5. Alice does an incremental sync covering steps 2–3. Alice's
`state_after` contains Bob's post-leave membership event from step 4

Alice should not see the new per-room display name of Bob.


## The fix

Copy what has been done for `_compute_state_delta_for_full_sync`: pass
`joined` down and, for rooms the user is no longer joined to, fetch the
memberships as of `end_token` via state groups (`get_state_ids_at`)
instead of current state.

2026-09-03 11:58:56 +01:00

..

api

Port Requester class to Rust. (#19828)

2026-06-09 10:26:04 +01:00

app

Use weakref to Python DatabasePool to allow homeserver to cleanly shutdown (#20009)

2026-07-28 10:04:48 +01:00

appservice

Add experimental support for letting application services proxy namespaces in the C-S and S-S API as per MSC4512 (#19972)

2026-08-28 13:45:54 +01:00

config

Fix config regression around falsy experimental_features (None) (#19987)

2026-07-22 09:07:29 -05:00

crypto

Update HomeserverTestCase.get_success(...) and friends to drive async Rust (Tokio runtime/thread pool) (#19871)

2026-07-02 15:20:38 -05:00

events

Add unit tests for parse_stripped_state_event (#20136)

2026-09-02 16:49:44 +01:00

federation

Add experimental support for letting application services proxy namespaces in the C-S and S-S API as per MSC4512 (#19972)

2026-08-28 13:45:54 +01:00

handlers

Fix state_after for left rooms including post-leave lazy-loaded memberships (#20169)

2026-09-03 11:58:56 +01:00

http

Add experimental support for letting application services proxy namespaces in the C-S and S-S API as per MSC4512 (#19972)

2026-08-28 13:45:54 +01:00

logging

Fix flakey test failing with "twisted.protocols.amp.TooLong" (#19832)

2026-06-10 17:33:21 +01:00

media

Fix WebP thumbnails losing their transparency (#20094)

2026-08-24 12:02:44 +00:00

metrics

Add metric to count number of non-deactivated users. (#19848)

2026-06-25 11:57:36 -05:00

module_api

Add Module API hooks that notify modules when events are delivered over federation. (#20019)

2026-07-30 12:32:27 +01:00

push

Rust database access via Python database connection pool v2 (#19878)

2026-07-07 13:07:35 -05:00

replication

Fix quarantined_media stream not being replicated (#20085)

2026-08-10 15:47:01 +01:00

rest

Fix state_after for left rooms including post-leave lazy-loaded memberships (#20169)

2026-09-03 11:58:56 +01:00

scripts

Write union types as X | Y where possible (#19111)

2025-11-06 14:02:33 -06:00

server_notices

Force keyword-args for clear default_config(server_name="test") usage (#19849)

2026-06-12 09:45:22 -05:00

state

Port Event class to Rust (#19701)

2026-06-02 11:05:38 +01:00

storage

Fix event_search background reindex skipping m.room.topic events (#20119)

2026-09-02 14:27:38 +01:00

synapse_rust

Update HomeserverTestCase.get_success(...) and friends to drive async Rust (Tokio runtime/thread pool) (#19871)

2026-07-02 15:20:38 -05:00

test_utils

Fix flakey test failing with "twisted.protocols.amp.TooLong" (#19832)

2026-06-10 17:33:21 +01:00

types

Replace usage of deprecated assertEquals with assertEqual (#19345)

2026-01-06 17:30:21 +00:00

util

Fix some paths being accessible at unintended locations with extra prefix components

2026-07-28 13:58:06 +01:00

__init__.py

Correctly mention previous copyright (#16820)

2024-01-23 11:26:48 +00:00

server.py

Fix tests that use homeserver_to_use=GenericWorkerServer not being able to be run standalone (#20017)

2026-08-10 16:34:56 -05:00

test_distributor.py

Cleanly shutdown SynapseHomeServer object (#18828)

2025-10-01 02:42:09 +00:00

test_event_auth.py

Port Event class to Rust (#19701)

2026-06-02 11:05:38 +01:00

test_mau.py

Force keyword-args for clear default_config(server_name="test") usage (#19849)

2026-06-12 09:45:22 -05:00

test_notifier.py

Update wait_for_stream_token(...) patterns and fix sync fetching with unbounded token (#19644)

2026-05-14 14:53:16 -05:00

test_phone_home.py

Move unique snowflake homeserver background tasks to start_background_tasks (#19037)

2025-10-13 10:19:09 -05:00

test_rust.py

Add missing type hints to tests. (#15027)

2023-02-08 19:52:37 +00:00

test_server.py

Rename the test_disconnect test helper so that pytest doesn't see it as a test. (#19486)

2026-02-20 15:37:34 +00:00

test_state.py

Force keyword-args for clear default_config(server_name="test") usage (#19849)

2026-06-12 09:45:22 -05:00

test_terms_auth.py

Introduce Clock.call_when_running(...) to include logcontext by default (#18944)

2025-09-22 10:27:59 -05:00

test_types.py

Expose MSC4354 Sticky Events over MSC4186 (Simplified) Sliding Sync. (#19591)

2026-06-23 13:04:36 +00:00

test_visibility.py

Add a FilteredEvent type to handle per-user data on events (#19640)

2026-04-16 09:47:08 +01:00

unittest.py

Fix assertIncludes printing None at the end of the message (#20020)

2026-07-29 13:30:39 -05:00

utils.py

Use a CPU-time budget for test_lock_contention to fix postgres flakiness (#19929)

2026-07-09 10:40:53 +01:00