Option to always disambiguate matrix users

[Stebalien]

Currently, matrix IDs are only shown when the display name is ambiguous in a room. However, I often chat with the same people across time and several rooms and would like to be able to easily tell if I'm actually am talking to the same person. Therefore, it would be nice to have a better way to uniquely identify a matrix user at a glance. #1201 addresses this to an extent but requires manual action.

One simple solution would be to have an option to always show matrix IDs: "Display Name (small-matrix-id)".
To shorten IDs, the homeserver could be removed if it matches the main address for the room or, alternatively, the current user's home server (although that punishes users who run their own homeservers).

[lampholder]

👍 I'd like to see this :)

[pafcu]

Considering element-hq/element-web#5827, element-hq/element-web#5826 and element-hq/element-web#1811 I'd go as far and say that this should not only be an option, it should be the default.

[turt2live]

Showing user IDs is undesirable and leads to a cluttered and nearly unusable interface. Until https://github.com/vector-im/riot-web/issues/116 is implemented, I strongly recommend not making it the default.

The mentioned issues should certainly be fixed, however that doesn't mean that everyone should have to suffer for someone's trolling behaviour.

[pafcu]

@turt2live Hence the option to turn it off. I believe software should aim to be secure by default.

(edit: Also, unicode is tricky enough that I doubt it will ever really be reliably fixed)

[turt2live]

I'm perfectly okay with the option, however I discourage making it default to always disambiguate.

[pafcu]

Perhaps making it room-configurable would be a good compromise? Communities that are especially worried about phishing and impersonation (e.g. the cryptocurrency-crowd) could have it enabled by default?

[turt2live]

I assumed granularity was implied given all the work I've put into making that happen.