Application Framework - Default Arguments for Document Opening Lead to Segmentation Faults

With [revision removed] the signature of TDocStd_Application::Open(...) has changed. It takes now a handle to a Message_ProgressIndicator which is by default initialized to be a null handle.

I consider this a bad design, because BinLDrivers_DocumentRetrievalDriver::Read accesses this progress indicator without performing a null handle check. Old code that is not passing a valid progress indicator will therefore crash because of a segmentation fault.

My proposal would be to add null handle checks everywhere or remove the default argument.

(Please not that the same issue is most probably also true for the Save(...) methods.)