Support underscore in domain name, or provide better exception

When calling on HttpClient.execute with a url that contain underscore ('_'), you get NullPointerException.
Tracing it down show that java.net.Uri complains that it is illegal name. Which is true according to the RFC.
But it seems that most browser allow it, and some companies support it.

I think HttpClient should either support underscores, or atleast provide a better exception.