"You invited %1$@" still shows a matrix id

[manuroe]

Steps to reproduce

This is a bug found by Hans while testing element-hq/element-meta#2395.

1. Open DM you started
2. Expand the room changes
3. The app displays ""You invited @bob:matrix.org" instead of Bob

Outcome

What did you expect?

A display name instead of a matrix id like on EW:

The invite event has a displayname field:

{
  "content": {
    "displayname": "testiosr123",
    "is_direct": true,
    "membership": "invite"
  },
  "origin_server_ts": 1663321374100,
  "sender": "@Manu:matrix.org",
  "state_key": "@testiosr123:matrix.org",
  "type": "m.room.member",
  "unsigned": {
    "age": 52463967527
  },
  "event_id": "$ryCuR93bduTjs-u5CPZQPNPnZZK_AQtp2_4Ys2SUXxk",
  "room_id": "!hQMQdhNMYBzbNfRaKh:matrix.org"
}

[manuroe]

It is fixed on EXA but not on EXI. See internal discussions.

Probably related, we display a user id in "state_event_room_invite" = "%1$@ invited %2$@" for %2$@ and in "state_event_room_invite_accepted" = "%1$@ accepted the invite". EXA is fine on those strings too.

[Velin92]

It is fixed on EXA but not on EXI. See internal discussions.

Probably related, we display a user id in "state_event_room_invite" = "%1$@ invited %2$@" for %2$@ and in "state_event_room_invite_accepted" = "%1$@ accepted the invite". EXA is fine on those strings too.

By checking the code I see that all our membership change events in the codebase were using the user ID instead of the display name, this is because EX-iOS was not suing the displayName coming from the Rust side that is attached to a roomMembershipChange event (to which the attached display name was recently added)
I imagine we want for all the state events to use the display name of the member subject to the member ship change is that correct? (Ofc the value that comes from the SDK is optional, so not all the state events will be managed with the display names, the ones that the SDK can't provide will still be using the userID)

[manuroe]

This is most of the time exact, @Velin92 . We want to avoid to display matrix ids most of the time. So, we should try to use the display name first. If not available, we default on the matrix id.

However, we want to display matrix ids when the user changes their display name or avatar and when there are banned as the display name can contain explicit content.
The whole list is in the parent issue: element-hq/element-meta#2395