When a User A kicks a User B and invites User B directly again, without User B syncing in between (because the client-app was closed for example), then the /sync response for User B includes the room in both rooms.invite and rooms.leave.
Since the client by default cannot rely on origin_server_ts for the order of events as there could be multiple servers with different time, some clients (like matrix-js-sdk) process the events in the wrong order (first the invite, then the leave) resulting in a wrong state on the client. The corresponding room cannot be used to chat, as the client thinks he left, when in reality he has an invitation to the room.
If the room is only inlcuded in either "leave" or "invite" (whichever is the newest event), then the client would always have the correct state
DMRobertson
commented
1 year ago
Description
When a User A kicks a User B and invites User B directly again, without User B syncing in between (because the client-app was closed for example), then the /sync response for User B includes the room in both
rooms.inviteandrooms.leave.Since the client by default cannot rely on
origin_server_tsfor the order of events as there could be multiple servers with different time, some clients (like matrix-js-sdk) process the events in the wrong order (first the invite, then the leave) resulting in a wrong state on the client. The corresponding room cannot be used to chat, as the client thinks he left, when in reality he has an invitation to the room.If the room is only inlcuded in either "leave" or "invite" (whichever is the newest event), then the client would always have the correct state
Here is a result of
/syncfor User B:/sync Result
```json { "next_batch": "s127655_2818331_4835_288127_209897_85_169_14999_0", "presence": { "events": [ { "type": "m.presence", "sender": "@ct_a18c34c2-ea65-4359-956e-b4c237c96e47:chat.krz.tools", "content": { "presence": "online", "last_active_ago": 17, "currently_active": true } } ] }, "device_lists": { "left": [ "@ctbot:chat.krz.tools" ] }, "device_one_time_keys_count": { "signed_curve25519": 0 }, "org.matrix.msc2732.device_unused_fallback_key_types": [], "device_unused_fallback_key_types": [], "rooms": { "invite": { "!sQgeWUrcqXvxvzkUqw:chat.krz.tools": { "invite_state": { "events": [ { "type": "m.room.avatar", "state_key": "", "content": { "url": "" }, "sender": "@ctbot:chat.krz.tools" }, { "type": "m.room.canonical_alias", "state_key": "", "content": { "alias": "#ctg_4b1a00f5-7753-469f-bf95-6bb3b7c1414d:chat.krz.tools" }, "sender": "@ctbot:chat.krz.tools" }, { "type": "m.room.create", "state_key": "", "content": { "room_version": "9", "creator": "@ctbot:chat.krz.tools" }, "sender": "@ctbot:chat.krz.tools" }, { "type": "m.room.join_rules", "state_key": "", "content": { "join_rule": "invite" }, "sender": "@ctbot:chat.krz.tools" }, { "type": "m.room.name", "state_key": "", "content": { "name": "Chattest" }, "sender": "@ctbot:chat.krz.tools" }, { "type": "m.room.topic", "state_key": "", "content": { "topic": "Gruppen-Chat einer Gruppe in testsilas.krz.tools" }, "sender": "@ctbot:chat.krz.tools" }, { "type": "m.room.member", "state_key": "@ctbot:chat.krz.tools", "content": { "membership": "join" }, "sender": "@ctbot:chat.krz.tools" }, { "type": "m.room.member", "sender": "@ctbot:chat.krz.tools", "content": { "membership": "invite", "displayname": "Admin Admin" }, "state_key": "@ct_a18c34c2-ea65-4359-956e-b4c237c96e47:chat.krz.tools", "origin_server_ts": 1671178716243, "unsigned": { "replaces_state": "$LbfQGkLijKPasqYizadgfKnvLW_OKYK4izrqDLegduU", "prev_content": { "reason": null, "membership": "leave" }, "prev_sender": "@ctbot:chat.krz.tools", "age": 41096 }, "event_id": "$elHhtOnT4Xy9mdNaHeJzVu5nVhKnRbjDEiFpN8BxBrc" } ] } } }, "leave": { "!sQgeWUrcqXvxvzkUqw:chat.krz.tools": { "timeline": { "events": [ { "type": "m.room.member", "sender": "@ctbot:chat.krz.tools", "content": { "reason": null, "membership": "leave" }, "state_key": "@ct_a18c34c2-ea65-4359-956e-b4c237c96e47:chat.krz.tools", "origin_server_ts": 1671178710797, "unsigned": { "replaces_state": "$pTOIJv3ViDwR7QyzOCLQatCwUyv5fQpNYSOaDIHXcdI", "prev_content": { "membership": "join", "displayname": "Admin Admin" }, "prev_sender": "@ct_a18c34c2-ea65-4359-956e-b4c237c96e47:chat.krz.tools", "age": 46542 }, "event_id": "$LbfQGkLijKPasqYizadgfKnvLW_OKYK4izrqDLegduU" } ], "prev_batch": "s127652_2818310_4829_288126_209897_85_169_14999_0", "limited": false }, "state": { "events": [] }, "account_data": { "events": [] } } } } } ```Steps to reproduce
Homeserver
chat.krz.tools
Synapse Version
1.73.0
Installation Method
I don't know
Database
PostgreSQL and the rest I don't know
Workers
Single process
Platform
running in a vm as far as I know
Configuration
No response
Relevant log output
Anything else that would be useful to know?
No response