Comment 31 for bug 911706

On the contrary, it is those other applications you list that behave stupidly when there is no Internet connection. For example, Firefox says "Firefox can't find the server at www.example.com", giving several possible explanations, when Ubuntu knows that only one of them is correct. Thunderbird gives you a stream of "Failed to connect to server" notification bubbles for however many mail accounts you have. And Transmission doesn't even suggest there's an error, merely saying "Remaining time unknown". None of them can tell you definitively what the problem is.

The reason those applications behave so stupidly is that they aren't asking Network Manager what the connection status is. The reason they aren't asking Network Manager what the connection status is is that they aren't assuming it will be present. And the reason they aren't assuming it will be present is that none of them are written specifically for Ubuntu.

Ubuntu Software Center and the Ubuntu One client are written specifically for Ubuntu. So they can assume Network Manager will be present, which means they can use it to find out what the connection status is, which means they can behave appropriately when there's no connection. That isn't a "serious design flaw", it's one of the benefits of running on a modern operating system.

Nobody would seriously suggest that you should be able to swap out the networking system in Windows or in OS X, and that applications should still work if you try. But *purely as a courtesy* to tinkerers who do that in Ubuntu, USC does the ping test if Network Manager is not running. (An alternative we seriously considered was just to make USC depend on Network Manager.) If you do swap out Network Manager, however, then as I said, it is your responsibility to do it completely.