Fix is to remove the CopyToAsync(...) override in DelegatingStream. The underlying Stream's implementation of this method will do the Right Thing:tm: and use methods that are correctly overridden in DelegatingStream and its subclasses, including ByteRangeStream.
Issue originally tracked in https://devdiv.visualstudio.com/DevDiv/_workitems/edit/690342
Fix is to remove the
CopyToAsync(...)override inDelegatingStream. The underlyingStream's implementation of this method will do the Right Thing:tm: and use methods that are correctly overridden inDelegatingStreamand its subclasses, includingByteRangeStream.Issue originally tracked in https://devdiv.visualstudio.com/DevDiv/_workitems/edit/690342