Max9 Offtopic, and 3.5 years late, but I cannot let this stand.
Austria became an independent duchy in the Holy Roman Empire under the Babenberger dynasty in 1156. Thus ending being a part of Bavaria. So obviously the Habsburger, taking over Austria, were taking over an independent state. (That does not change that they might have feudally bound to Bavaria in their traditional western territories, the Holy Roman Empire was a mess at the best of times, but then who cares, they lost them rather quickly any way.)
Sure there have been border quarrels over the centuries, but that does not change the basics.