This crash appears to happen on dragging anything on gnome-shell. Eg: 1. If a window is dragged in shell overview 2. if a window in desktop list (in the right side) is dragged. 3. if some icon from Application list is dragged.
Also, the immediately followed drag after the first failure results in a total crash losing all the open window and goes back to slim login. So the bug severity may be increased if this is reproducible to some one. Thanks