Allow disabling private messages. Fixes #3640

[dessalines]

This adds a local user setting: enable_private_messages default true.

It then checks when sending to a local user, that both you and the recipient have that setting enabled.

It also checks on an apub private message receive, that you have it enabled, before creating it.

[Nutomic]

This is not enough, you also need to federate the setting as part of Person. That way pm buttons can properly be disabled for remote users too. I didnt find any existing property for this purpose, so you can simply call it enable_private_messages and add it to the context.

[richardARPANET]

This is greatly needed 👍 Can there also be a global setting?

[dessalines]

Global setting should probably be in a different PR / issue. This is specifically to prevent harassment on a user-level.

[Nutomic]

Outdated, feel free to reopen when you work on it again.

[dessalines]

This is not enough, you also need to federate the setting as part of Person. That way pm buttons can properly be disabled for remote users too. I didnt find any existing property for this purpose, so you can simply call it enable_private_messages and add it to the context.

I'm not sure how to handle this, because its a local user setting, not something that gets federated with person.

For example the into_json fields here don't select local user settings, only fields from person.

[dessalines]

The check for apub is done here, so it is working, its just not a publicized setting, so like blocks, senders don't know.

[Nutomic]

This check is not really needed because the recipient of a federated private message is always a local user.

[dessalines]

K fixed.

[Nutomic]

Ah youre also getting the same random image test failure as in private community PR.

[dessalines]

Weird, we haven't touched that at all.

[SleeplessOne1917]

This can be expressed in a different way that you may or may not prefer:

  local_user_view
    .local_user
    .enable_private_messages
    .then_some(())
    .ok_or_else(|| LemmyErrorType::CouldntCreatePrivateMessage.into())

[dessalines]

Not a huge fan of that one at least in this case, because it unnecessarily coerces it into an option, when it's already a bool.