will you be replacing getIdentity everywhere?

Not really as this is different than getIdentity in terms of logic. GetIdentity is basically the identity of the application which comes from the authentication process. While this here can be anything where the view or model should work with. But as I said, I'm open here for suggestions as the similarities are very obvious.

Just when I thought I understood the reason for this PR

Why not make a trait to get the application object and the go from there?

Don't think so it would be a good decision to pass around the application in whole core. Like that there is only a dependency to a simple user and not the app. It brings the benefit to be usable on places where no application is available.

Here, the current user object will only be available in model if the model is created by our normal MVC workflow (users access to the component via web browser). What if model is created by by MVCFactory ? In this case, getCurrentUser() would return null and we will get error (fatal error or at least logical error). Am I right?

Nope https://github.com/joomla/joomla-cms/pull/37498/files#diff-cd69155c336e480348cacd600fe8300407ed0219ce97ed7f83324fef100d311dR41

That's not current user, but an empty user object?

After reading your comment a couple of times I think I do understand what you mean now. So when an extension is loading a model like $app->bootComponent('content')->getMVCFactory()->createModel('Article', 'Administrator') then the user is not the identity from the global application object. Is this what you mean? In this case I would probably fallback to Factory::getApplication()->getIdentity() here instead of an empty user and deprecate that usage for 5.

Yes, that's what I wanted to say.

@laoneo We have a codestyle failure:

FILE: /********/src/libraries/src/User/CurrentUserTrait.php

----------------------------------------------------------------------

FOUND 1 ERROR AFFECTING 1 LINE

----------------------------------------------------------------------

 43 | ERROR | [x] No space found after comma in argument list

    |       |     (Generic.Functions.FunctionCallArgumentSpacing.NoSpaceAfterComma)

@joomdonation Is everything OK for you now on this PR?

@roland-d The logical bug I concerned before is fixed with latest change, so it is fine now. The architecture change in this PR, right or wrong, I'm not qualify enough to say, sorry. So it's up to you to decide :D .

Thanks everybody