regression - 4.0 update broke space-restrictive room joinability

[williamkray]

Describe the bug

i run several rooms that can only be joined by members of the parent space. in cinny, in the space lobby, rooms that are not joined that have this restrictive membership configuration are only shown as "private room", with no option to view the room information or join it.

Reproduction

1. create a space
2. create room in space, set join restriction to only members of the space able to join
3. leave the room
4. go to the space lobby
5. surprise! you cannot join the room again even though you are a member of the space. you cannot see information about the room. instead you see something like this:

Expected behavior

room lobby should show the room icon, name, address, description, etc. for members of the space, and should allow people to join the room.

Platform and versions

web, v4.0.3

Additional context

No response

[kfiven]

When you left the room, were you the only member of it?

[williamkray]

no, i invited a bot i control as well... so if it were critical, i could use the bot to re-invite myself. but this wasn't necessary for this testing. the room continues to exist and have users in it, though, if that's what you're asking.

[ajbura]

from the icon it looks like it's join rules are private

[ajbura]

what is the homeserver of your account? just wanna to make sure it's not https://github.com/element-hq/synapse/issues/17143

[williamkray]

homeservers affected are mssj.me and jobmachine.org.

another room that is affected in element, vs cinny:

element space room list shows the room: (strangly the "Join" button disappears when i take a screenshot, but there's a big green "Join" button there)

element screenshot showing the room join rules (as seen from another account with access to the room):

cinny space lobby shows:

[williamkray]

another real life example: i'm apparently not in one of the rooms in the Cinny space, but i cannot join it.

[ajbura]

Could you please try joining your room which is shown as private by copying it's room_id via "Home" > "Join with Address", it looks like to me as a server side issue (https://github.com/element-hq/synapse/issues/17143).

the one private room in cinny space is actually a private room.

[williamkray]

the one private room in cinny space is actually a private room.

ok, well i just replicated the behavior with the Announcements room, which is not a private room:

and then after i left it:

i was indeed able to rejoin the announcements room with the room ID, however, now it shows up under the Home category.

if i navigate back to the Cinny space lobby, i can see the room description, and click the arrow to go to the room, but it shows me a landing page:

and then clicking that button takes me back to the view of the room in the Home pane.

i should clarify that for me, the Cinny space is a sub-space of a broader personal space i've created for matrix rooms.

[ajbura]

Thanks for feedback. i got you. Room shown as private in space lobby will be fixed with synapse MR https://github.com/element-hq/synapse/pull/17194

the other issue of room appearing in home is Cinny's issue.

[kfiven]

Should be fixed for synapse user with synapse v1.114.0

[williamkray]

i upgraded to synapse 1.114.0 (for both the server my account is on, and the server that is "home" to this space and most of its rooms) this morning and still see this issue after clearing cache and reloading:

[kfiven]

Could you please check the same account on element? I have tested this yesterday with two different accounts and was getting all the rooms.

[williamkray]

confirmed rooms appear correctly in element-web, v1.11.76

the following room correlates to one of the above "Unknown" private rooms above, and shows all metadata about the room as well as offering the option to join (join restriction is enabled, only members of the space are meant to join).