04652334f3
Docking uses window overlays during feedback and these have to be stopped and changed if you move the target from window to window. The logic of changing the window that gets the overlay will sometimes fail when the target window is null and old window was null - it gets stopped (because they are equal) but not started again. This PR just adds a check for null window. Pull Request: https://projects.blender.org/blender/blender/pulls/126906