Cannot view room from space home after upgrading

[Johennes]

Steps to reproduce

I upgraded the Element web app team room which was in the WAT space. After the room upgrade, I can see both the old and new room in the m.space.child state event. On the space home page, the room sows up (a single time) but clicking the "view" button or trying to delete it does nothing.

Outcome

What did you expect?

The buttons to work as they did before and to take me to the new room.

What happened instead?

Nothing.

Operating system

macOS

Application version

Element Desktop nightly

How did you install the app?

No response

Homeserver

No response

Will you send logs?

No

[weeman1337]

Can reproduce. O-Occasional spaces are quite common. S-Major because I cannot join or view an upgraded room, that I can see in the space list.

[Johennes]

Console error on web:

Uncaught TypeError: room is undefined
    showRoom SpaceHierarchy.tsx:365
    onViewRoomClick SpaceHierarchy.tsx:807
    onViewRoomClick SpaceHierarchy.tsx:480
    onPreviewClick SpaceHierarchy.tsx:120
    React 14
    unstable_runWithPriority scheduler.development.js:468
    React 15
    loadApp init.tsx:150
    start index.ts:228
    async* index.ts:239
    <anonymous> bundle.js:1444
    __webpack_require__ bundle.js:838
    fn bundle.js:130
    <anonymous> bundle.js:1068
    __webpack_require__ bundle.js:838
    <anonymous> bundle.js:1055
    <anonymous> bundle.js:1058
2 SpaceHierarchy.tsx:365:8

[Johennes]

Looks like /_matrix/client/v1/rooms/{roomId}/hierarchy doesn't return the new room. That in turn is likely because the new room seems to be missing the via parameter in

Old room

{
  "content": {
    "suggested": false,
    "via": [
      "matrix.org",
      "element.io",
      "riot.ovh"
    ]
  },
  "origin_server_ts": 1674562905343,
  "sender": "@johannesm:element.io",
  "state_key": "...",
  "type": "m.space.child",
  "unsigned": {
    "age": 241155595
  },
  "event_id": "...",
  "room_id": "..."
}

New room

{
  "content": {},
  "origin_server_ts": 1674662312761,
  "sender": "@johannesm:element.io",
  "state_key": "...",
  "type": "m.space.child",
  "unsigned": {
    "age": 141748160
  },
  "event_id": "...",
  "room_id": "..."
}

via is required and:

When not present or invalid, the child room is not considered to be part of the space.

[Johennes]

And finally toLocalRoom converts the old room in the hierarchy returned by the server to the latest room in the room upgrade history:

const toLocalRoom = (cli: MatrixClient, room: IHierarchyRoom): IHierarchyRoom => {
    const history = cli.getRoomUpgradeHistory(room.room_id, true);
    const cliRoom = history[history.length - 1];
    if (cliRoom) {
        return {
            ...room,
            room_id: cliRoom.roomId,

So that explains why the room with the new ID is used in the room list.

[Johennes]

So I think there are two bugs here:

1. When upgrading the room, the new one was added into the old one's space but no via parameter was set, technically making it not part of the space.
2. When resolving the latest room version, we don't verify whether the corresponding room is actually in the space or not.

[Johennes]

So I think there are two bugs here:

1. When upgrading the room, the new one was added into the old one's space but no `via` parameter was set, technically making it _not_ part of the space.

2. When resolving the latest room version, we don't verify whether the corresponding room is actually in the space or not.

2. was fixed with Ensure room is actually in space hierarchy when resolving its latest version matrix-org/matrix-react-sdk#10010.

[Johennes]

I've tested this again locally for another room and I'm not able to reproduce issue 1 anymore. The via parameter is correctly set. Unsure what went wrong the last time. Closing this for now.