/_matrix/client/r0/profile returns 404 if only displayname is not set

[weeman1337]

Description

If a user has been created without a displayname, requests are sent to /_matrix/client/r0/profile return a 404 response.

Steps to reproduce

• Create a user without displayname but an avatar
• Try to get the profile for the user

Expected: got a response with empty displayname
What happens: 404

Homeserver

matrix.jamesdemo.ems-support-self-serve.element.io

Synapse Version

1.84.0

Installation Method

I don't know

Database

I don't know

Workers

I don't know

Platform

EMS

Configuration

No response

Relevant log output

-

Anything else that would be useful to know?

Link to source

synapse/synapse/handlers/profile.py

Line 71 in 99b7b80

if profileinfo.display_name is None:

[t3chguy]

This almost matches the spec as I read it https://spec.matrix.org/v1.7/client-server-api/#get_matrixclientv3profileuserid

404 There is no profile information for this user or this user does not exist.

Not having a name or avatar set would be "no profile information" - Synapse only checking displayname is wrong though

[clokep]

I did some quick testing and there are users with a null displayname and a configured avatar, so yeah this seems wrong.