CurrentUser incorrectly resolves empty User instance

[anned20]

Laravel Version

11.22.0

PHP Version

8.2.16

Database Driver & Version

No response

Description

We are using the new ContextualAttribute to get the CurrentUser in our controller methods. This works fine, until there is no user in the guard.

The function resolve in the attribute correctly returns null, but the Container then resolves the parameter to a new User instance if there is a type-hint for a User on the parameter. This even happens when the parameter type is indicated as optional.

Steps To Reproduce

class SomeController
{
    public function someMethod(
        #[CurrentUser]
        ?User $user
    ): void {
        dd($user);
    }
}

When executing this code without being logged in (having no available user), the $user will contain an empty model.

[EranNL]

This could also potentially "break" some edge cases in the new features from this PR: #53080
When you have an optional parameter in your URL, I guess you would not want an empty model when trying to resolve it, it would be better to resolve to null in my opinion.

[alen-androsevic]

Any fixes?