[minor] Incorrect invitee displayname when inviting at room creation

[matrixbot]

This issue was originally created by @anton-molyboha at matrix-org/dendrite#3348.

Background information

• Dendrite version or git SHA: 0.13.6
• SQLite3 or Postgres?: Postgres
• Running in Docker?: no
• go version: 1.21.5
• Client used (if applicable): curl, Element Desktop

Description

The room creation endpoint /_matrix/client/v3/createRoom accepts an optional list of accounts to invite to the newly created room.
When I invite somebody via this endpoint, their displayname shows as that of the inviter rather than invitee.

(sorry for poor wording, see "steps to reproduce" below, they are much more clear)

Steps to reproduce

• run

curl --data '{"name": "Test room", "invite": ["@anton:rendezvous.anton.molyboha.me"]}' --header 'Authorization: Bearer <redacted>' https://rendezvous.anton.molyboha.me/_matrix/client/v3/createRoom

• accept the invitation in Element Desktop (or another client)
• look at the source of the invitation message. What I see is:

{
  "content": {
    "displayname": "test1",
    "membership": "invite"
  },
  "event_id": "<redacted>",
  "origin_server_ts": 1711569816249,
  "sender": "@test1:rendezvous.anton.molyboha.me",
  "state_key": "@anton:rendezvous.anton.molyboha.me",
  "type": "m.room.member",
  "unsigned": {
    "invite_room_state": [
      {
        "content": {
          "creator": "@test1:rendezvous.anton.molyboha.me",
          "room_version": "10"
        },
        "sender": "@test1:rendezvous.anton.molyboha.me",
        "state_key": "",
        "type": "m.room.create"
      },
      {
        "content": {
          "displayname": "test1",
          "membership": "join"
        },
        "sender": "@test1:rendezvous.anton.molyboha.me",
        "state_key": "@test1:rendezvous.anton.molyboha.me",
        "type": "m.room.member"
      },
      {
        "content": {
          "join_rule": "invite"
        },
        "sender": "@test1:rendezvous.anton.molyboha.me",
        "state_key": "",
        "type": "m.room.join_rules"
      },
      {
        "content": {
          "name": "Test room"
        },
        "sender": "@test1:rendezvous.anton.molyboha.me",
        "state_key": "",
        "type": "m.room.name"
      }
    ]
  },
  "room_id": "<redacted>:rendezvous.anton.molyboha.me"
}

Notice "displayname": "test1" part. The actual displayname for @anton:rendezvous.anton.molyboha.me is unset, so I expected "displayname" field to either be absent or to say "anton".

[matrixbot]

This comment was originally posted by @S7evinK at matrix-org/dendrite#3348 (comment).

This should already be fixed by #3326 on main.

[matrixbot]

This comment was originally posted by @anton-molyboha at matrix-org/dendrite#3348 (comment).

Oh, my bad. Thank you!