@gpatel-fr said:
The idea is that it's a generic feature, not something specific to Ubuntu Touch.
Well yes and no. It is a generic feature to detect option 114 and make the request to the API. BUT It is an OS sepcific feature to decide how you are going to display the captive portal. Here I display it using urlDispatcher via DBus that is an UT-specific feature that could hardly be upstreamed. Android has it's own mini-browser designed exclusively to display captive portal.
So this is kind of hard to have a generic way to handle captive portals in all OS that embed NetworkManager, independenty of the OS specifics. And all the existing OS (Android, iOS, Windows, MacOS) handle captive portal each, their own way.
I don't think in that regard UT should limit itself to what is availiable upstream, i.e keep basic things not working and not implemented, while it requires a 20 line script to have things running fine. If some day NetworkManager improve it's implementation, it will allways be time to use it then.