No Avatar for rooms converted to dm

[toger5]

Steps to reproduce

1. From @A:domain.org create a new group with a user you already have a dm (@b.domain.org) with. (normal group, group name "test")
2. join with both users
3. observe no avatar on EX (since its a group with no avatar)
4. Convert the room into dm on EW on both accounts (just the acc used on EX should be sufficient)
5. RENAME the group to "" (m.room.name) -> it will get renamed on EX to the other users name (DM semantics). It will NOT load the avatar! (it will generate an avatar using the first letter however...)

Outcome

What did you expect?

To also see the avatar in the room list.

What happened instead?

I did see a generated avatar and when going into the room details I could see the two avatars in the nice EX stacked avatar DM design.

Your phone model

No response

Operating system version

No response

Application version and app store

No response

Homeserver

No response

Will you send logs?

Yes

Are you willing to provide a PR?

Yes

[frebib]

Sounds similar to #3911 (that you raised, then closed) in favour of #3581
In the time since those were raised, I'm thinking that instead the issue I'm having might actually be more closely related to what you're describing here and less/nothing to do with the 3rd participant. It's also more likely a bug in the Rust SDK

[frebib]

Just to really solidify this behaviour - I took a regular DM that I've had for ages and set m.room.name to {”name":""} and the avatar disappeared in EX. Redacting that state event makes it come back. Last I looked into this- Rust SDK returns the avatar url as null but I can't quite work out why setting the name causes this.