fix(useOutlet): don't wrap in ContextProvider if no child route

[mcansh]

closes #8477

[goffioul]

I'm confused by the proposed fix. Using useOutlet(null) (or <Outlet context={null} />) is still a valid use case and it doesn't mean that you don't want to provide any context to the child component, but you want to provide a null value for the context.

I could be wrong, but is there a valid use case where you'd still want to render OutletContext.Provider while outlet is null? It seems to me that if outlet is null, useOutlet() should just return null, whether or not a context is provided as argument.

Whether or not to wrap outlet with the context provider is IMO another story. I don't think you can decide solely on the context value, can you?

[mjackson]

It seems to me that if outlet is null, useOutlet() should just return null, whether or not a context is provided as argument.

@goffioul You are correct. This was fixed in 7d16c39