The Location class has prepareExternalUrl() that takes base href into account.
You can also try to inject constructor(@Inject(APP_BASE_HREF) href:string)
It seems APP_BASE_HREF can't be injected anymore without explicitly providing it.
PlatformLocation provides more details about the URL:
import {PlatformLocation } from '@angular/common';
constructor(platformLocation: PlatformLocation) {
console.log((platformLocation as any).location);
console.log((platformLocation as any).location.href);
console.log((platformLocation as any).location.origin);
}
Plunker example