Lazy loading: the CS API should provide heroes if room name is ""

[manuroe]

Description

Riot clients remove an existing display name by setting an empty string ("").
If that happens on live, matrix clients will be likely to compute a display name like "Bob and 3 others" as specced by the room summary.
But if a matrix client does an initial sync, it will give an "Empty room" name to the room because it receives no heroes.

Steps to reproduce

On a Riot client:

• create a room with people in there
• set a room display name
• remove it
• Do an initial /sync by clearing the cache.

-> The room will be named "Empty room" instead of "Bob and 3 others" or stg.

[Half-Shot]

I kinda wish matrix client's set the name state to either empty content or nulled the name rather than an empty string as it's probably a valid thing in itself to have your room title be empty. However, it's probably not worth trying to change that behaviour now...

[richvdh]

I don't think it's practical to fix this without a spec which defines how it is supposed to work, cf matrix-org/matrix-spec-proposals#1868.