`m.direct` account data is modified when starting typing and clearing composer within a DM

[turt2live]

Steps to reproduce

1. With user A create a DM with user B
2. Let user B join
3. Type a message with user B
4. Open network tab
5. Notice m.direct hit

Outcome

What did you expect?

No account data changes related to DMs when interacting with the composer.

What happened instead?

Lots of network requests. It's unclear if this is further caused by DMs being "corrupted" by the RoomListStore: !room:localhost was found in DMs but the room is not in the store

Only happens for invited user B

Operating system

Windows 10

Browser information

Edge

URL for webapp

local build of staging.element.io

Application version

Staging

Homeserver

localhost, 1.73.0

Will you send logs?

Yes

[turt2live]

copy/pasting for further context:

so the call to set m.direct is coming from RoomView's updateRoomMembers function, which is seemingly being triggered by a room state update in the js-sdk. That room state update is happening because the typing notification for ourselves is coming down /sync, which appears to have an empty timeline and state array for the room, which is enough to trigger the js-sdk's setStateEvents function within RoomState (specifically, called from here). At the end of setStateEvents, we trigger a room state update, even if we didn't change anything.

I'm not seeing any obvious recent changes which would cause this sort of behaviour, so a possible theory is it's Synapse returning (legal) JSON with extra, empty, fields (thus triggering our code to set state from an empty array). That said, it would be a very weird bug to show up only now and not ages ago.

[weeman1337]

Can reproduce - updated steps in description

[weeman1337]

Last version not showing this behaviour is 1.10.6
Starts with 1.10.7

[weeman1337]

Found the change introducing this behaviour matrix-org/matrix-react-sdk@c257bc3#diff-13590ebbbcd62256ff3ead94de2e6be41867b82ad9e0470c4b63ff63c1f5f78bR287

[turt2live]

I'm a bit worried that a more recent change has made this worse, as a 10 month-old bug would have manifested sooner.

ftr, this issue appears to cause DM status to be lost on rooms, as it calculates the wrong DM state.

[weeman1337]

ftr, this issue appears to cause DM status to be lost on rooms, as it calculates the wrong DM state.

Isn't this another issue? Like sending the wrong m.direct content?