is_direct field on /createRoom body does not automatically mark the room as a DM

[DMRobertson]

Link to problem area: https://spec.matrix.org/v1.9/client-server-api/#creation and https://spec.matrix.org/v1.9/client-server-api/#direct-messaging

Issue
I naively expected that passing this flag to /createRoom would automatically mark the created room as a DM in the creator's account data. This seems not to be the case: the referenced bits of the spec mainly talk about propagating the is_direct flag to invitees.

(Might be appropriate to close this as WONTFIX if this doesn't bother today's clients, and if canonical DMs will fix it.)

[DMRobertson]

(I did search for an issue, but couldn't find anything matching is_direct.)

[richvdh]

The spec is fairly explicit that the clients have to do this themselves:

The invitee’s client may use the is_direct flag in the m.room.member event to automatically mark the room as a direct chat but this is not required: it may for example, prompt the user, or ignore the flag altogether.

Both the inviting client and the invitee’s client should record the fact that the room is a direct chat by storing an m.direct event in the account data using /user/<user_id>/account_data/.

[DMRobertson]

Sure; I'm more complaining that this is a bit of a crap situation if you're expecting to do read the DM flag. (There's an extra RTT and a transitory flicker where you've asked for a DM and got something but not a DM yet.)

The context this came up on is the sliding sync proxy: we only want to consider rooms with the DM flag to inherit members' avatars: element-hq/element-x-ios#2003 (comment)

[richvdh]

fair enough. It's probably something that could be changed.

Waiting for canonical DMs is likely to be a long wait.