Windows: Undocking and docking a widget doesn't work with finger

The example attached can be used to reproduce the issue.

Steps to reproduce:
1. run the application with a touch device (or with a machine which has a touch screen)
2. start dragging the dock widget outside the application window with a finger
3. drop the dock widget outside the application window
4. start dragging the dock widget to the application window with a finger

Expected result:
The dock window gets docked to the mainwindow

Actual result:
The dock window stays floating on top of the mainwindow and it is only possible to dock it by using the mouse