Sliding sync returns `initial: false` for a first response

[Hywan]

Description

Sliding sync returns the first response with initial: false. Not only it's incorrect, but if initial is not true, other data won't be attached, like joined_count or invite_count (and maybe others).

Steps to reproduce

• git clone https://github.com/matrix-org/matrix-rust-sdk
• remove #[ignore] in testing/matrix-sdk-integration-testing/src/tests/sliding_sync/notification_client.rs on top of the test_notification method,
• run cd testing/matrix-sdk-integration-testing/ && docker compose -f assets/docker-compose.yml up -d && cd -
• run cargo nextest run --retries 0 --fail-fast -p matrix-sdk-integration-testing -- sliding_sync::notification_client

Homeserver

local, synapse v1.114

Synapse Version

1.114

Installation Method

Docker (matrixdotorg/synapse)

Database

postgresql I suppose

Workers

I don't know

Platform

container on macOS

Configuration

No response

Relevant log output

Rust sends the following request:

Request {
    pos: None,
    conn_id: Some(
        "notifications",
    ),
    txn_id: Some(
        "3454cbd235af4fc2884c189df99df1b1",
    ),
    timeout: Some(
        1s,
    ),
    lists: {
        "invites": List {
            ranges: [
                (
                    0,
                    16,
                ),
            ],
            room_details: RoomDetails {
                required_state: [
                    (
                        "m.room.encryption",
                        "",
                    ),
                    (
                        "m.room.member",
                        "$LAZY",
                    ),
                    (
                        "m.room.member",
                        "$ME",
                    ),
                    (
                        "m.room.canonical_alias",
                        "",
                    ),
                    (
                        "m.room.name",
                        "",
                    ),
                    (
                        "m.room.power_levels",
                        "",
                    ),
                ],
                timeline_limit: Some(
                    8,
                ),
            },
            include_heroes: None,
            filters: Some(
                ListFilters {
                    is_invite: Some(
                        true,
                    ),
                    not_room_types: [
                        Space,
                    ],
                },
            ),
        },
    },
    room_subscriptions: {
        "!kJhFVgLmSwHmoFDgDv:matrix-sdk.rs": RoomSubscription {
            required_state: [
                (
                    "m.room.encryption",
                    "",
                ),
                (
                    "m.room.member",
                    "$LAZY",
                ),
                (
                    "m.room.member",
                    "$ME",
                ),
                (
                    "m.room.canonical_alias",
                    "",
                ),
                (
                    "m.room.name",
                    "",
                ),
                (
                    "m.room.power_levels",
                    "",
                ),
            ],
            timeline_limit: Some(
                16,
            ),
            include_heroes: None,
        },
    },
    extensions: Extensions {
        to_device: ToDevice {
            enabled: None,
            limit: None,
            since: None,
            lists: None,
            rooms: None,
        },
        e2ee: E2EE {
            enabled: None,
        },
        account_data: AccountData {
            enabled: Some(
                true,
            ),
            lists: None,
            rooms: None,
        },
        receipts: Receipts {
            enabled: None,
            lists: None,
            rooms: None,
        },
        typing: Typing {
            enabled: None,
            lists: None,
            rooms: None,
        },
        other: {},
    },
}

Rust receives the following response:

```rust
Response {
    initial: false,
    txn_id: None,
    pos: "70/s1235_228_0_1_91_1_67_333_0_1",
    lists: {
        "invites": List {
            count: 1,
        },
    },
    rooms: {
        "!kJhFVgLmSwHmoFDgDv:matrix-sdk.rs": Room {
            name: Some(
                "Kingdom of Integration Testing",
            ),
            avatar: Undefined,
            initial: Some(
                true,
            ),
            is_dm: None,
            invite_state: Some(
                [
                    Raw::<ruma_events::enums::AnyStrippedStateEvent> {
                        json: RawValue(
                            {"type":"m.room.join_rules","state_key":"","content":{"join_rule":"invite"},"sender":"@alice336083335834587528043410278571228479798:matrix-sdk.rs"},
                        ),
                    },
                    Raw::<ruma_events::enums::AnyStrippedStateEvent> {
                        json: RawValue(
                            {"type":"m.room.create","state_key":"","content":{"room_version":"10","creator":"@alice336083335834587528043410278571228479798:matrix-sdk.rs"},"sender":"@alice3360833358345
                        ),
                    },
                    Raw::<ruma_events::enums::AnyStrippedStateEvent> {
                        json: RawValue(
                            {"type":"m.room.member","state_key":"@alice336083335834587528043410278571228479798:matrix-sdk.rs","content":{"displayname":"Alice, Queen of Cryptography","membership":"join
                        ),
                    },
                    Raw::<ruma_events::enums::AnyStrippedStateEvent> {
                        json: RawValue(
                            {"type":"m.room.member","state_key":"@bob130057355307418395329784277089848882443:matrix-sdk.rs","content":{"is_direct":true,"displayname":"bob130057355307418395329784277089
                        ),
                    },
                ],
            ),
            unread_notifications: UnreadNotificationsCount {
                highlight_count: Some(
                    0,
                ),
                notification_count: Some(
                    0,
                ),
            },
            timeline: [],
            required_state: [],
            prev_batch: None,
            limited: false,
            joined_count: None,
            invited_count: None,
            num_live: None,
            bump_stamp: Some(
                1234,
            ),
            heroes: None,
        },
    },
    extensions: Extensions {
        to_device: None,
        e2ee: E2EE {
            device_lists: DeviceLists {
                changed: [],
                left: [],
            },
            device_one_time_keys_count: {},
            device_unused_fallback_key_types: None,
        },
        account_data: AccountData {
            global: [
                Raw::<ruma_events::enums::AnyGlobalAccountDataEvent> {
                    json: RawValue(
                        {"type":"m.push_rules","content":{"global":{"underride":[{"conditions":[{"kind":"event_match","key":"type","pattern":"m.call.invite"}],"actions":["notify",{"set_tweak":"sound",_tweak":"highlight","value":false}],"rule_id":".m.rule.encrypted","default":true,"enabled":true},{"conditions":[{"kind":"event_match","key":"type","pattern":"im.vector.modular.widgets"},{"kind":"event_match","key":"content.type","pattern":"jitsi"},{"kind":"event_match","key":"state_key","pattern":"*"}],"actions":["notify",{"set_tweak":"highlight","value":false}],"rule_id":".im.vector.jitsi","default":true,"enabled":true}],"sender":[],"room":[],"content":[{"actions":["notify",{"set_tweak":"highlight"},{"set_tweak":"sound","value":"default"}],"rule_id":".m.rule.contains_user_name","default":true,"pattern":"bob130057355307418395329784277089848882443","enabled":true}],"override":[{"conditions":[],"actions":[],"rule_id":".m.rule.master","default":true,"enabled":false},{"conditions":[{"kind":"event_match","key":"content.msgtype","pattern":"m.notice"}],"actions":[],"rule_id":".m.rule.suppress_notices","default":true,"enabled":true},{"conditions":[{"kind":"event_match","key":"type","pattern":"m.room.member"},{"kind":"event_match","key":"content.membership","pattern":"invite"},{"kind":"event_match","key":"state_key","pattern":"@bob130057355307418395329784277089848882443:matrix-sdk.rs"}],"actions":["notify",{"set_tweak":"highlight","value":false},{"set_tweak":"sound","value":"default"}],"rule_id":".m.rule.invite_for_me","default":true,"enabled":true},{"conditions":[{"kind":"event_match","key":"type","pattern":"m.room.member"}],"actions":[],"rule_id":".m.rule.member_event","default":true,"enabled":true},{"conditions":[{"kind":"event_property_contains","key":"content.m\\.mentions.user_ids","value":"@bob130057355307418395329784277089848882443:matrix-sdk.rs"}],"actions":["notify",{"set_tweak":"highlight"},{"set_tweak":"sound","value":"default"}],"rule_id":".m.rule.is_user_mention","default":true,"enabled":true},{"conditions":[{"kind":"contains_display_name"}],"actions":["notify",{"set_tweak":"highlight"},{"set_tweak":"sound","value":"default"}],"rule_id":".m.rule.contains_display_name","default":true,"enabled":true},{"conditions":[{"kind":"event_property_is","key":"content.m\\.mentions.room","value":true},{"kind":"sender_notification_permission","key":"room"}],"actions":["notify",{"set_tweak":"highlight"}],"rule_id":".m.rule.is_room_mention","default":true,"enabled":true},{"conditions":[{"kind":"sender_notification_permission","key":"room"},{"kind":"event_match","key":"content.body","pattern":"@room"}],"actions":["notify",{"set_tweak":"highlight"}],"rule_id":".m.rule.roomnotif","default":true,"enabled":true},{"conditions":[{"kind":"event_match","key":"type","pattern":"m.room.tombstone"},{"kind":"event_match","key":"state_key","pattern":""}],"actions":["notify",{"set_tweak":"highlight"}],"rule_id":".m.rule.tombstone","default":true,"enabled":true},{"conditions":[{"kind":"event_match","key":"type","pattern":"m.reaction"}],"actions":[],"rule_id":".m.rule.reaction","default":true,"enabled":true},{"conditions":[{"kind":"event_match","key":"type","pattern":"m.room.server_acl"},{"kind":"event_match","key":"state_key","pattern":""}],"actions":[],"rule_id":".m.rule.room.server_acl","default":true,"enabled":true},{"conditions":[{"kind":"event_property_is","key":"content.m\\.relates_to.rel_type","value":"m.replace"}],"actions":[],"rule_id":".m.rule.suppress_edits","default":true,"enabled":true}]}}},
                    ),
                },
            ],
            rooms: {},
        },
        receipts: Receipts {
            rooms: {},
        },
        typing: Typing {
            rooms: {},
        },
    },
}

### Anything else that would be useful to know?

_No response_

[Hywan]

There is an error from the client stack. The top-level initial value doesn't exist in the MSC4186, but is expected on the client side, which defaults to false if absent.

The joined_count is missing because the server doesn't want to leak too much data about non-joined rooms. I've commented the MSC accordingly. We can update our test suite on the Matrix Rust SDK side.

Closing this issue.