Drag&Drop - Dragging may lead to sporadic explorer process crash

r75779 gcc dbg

Dragging (without ever dropping) may lead to an explorer crash.
I can usually make this happen within about a minute, but I unfortunately can not give exact reproduction steps here.

reproduction is a bit easier than video.webm even:
-Open first shell-browser
-open another file-browser window
-Drag "Program files" folder from first shell browser (never drop it)
-While never releasing the mouse button, continue to move the cursor chaotically and make sure you cross the Window borders multiple times.
At some point explorer will crash. It does not necessarily happen when crossing a specific object or pixel. Atm it appears to be a bit random.

crash.log covers what I did when I created the video and ends exactly after the explorer-restart.
It's not that hard as it sounds to make it happen. You can try it and will most likely succeed within a minute.