Crash when dragging library items outside of Designer window

When opening a new QMLproject from the wizard I sometimes get a crash of my windowing server when taking e.g. the Text element from the library and dragging that outside of the designer window.

The first time I triggered this was when I tried to drop the Text element onto the preview window.

I have reproduced this issue several times, but it is not 100% reliable: I had to try about 10 times to drag an element outside of the window to trigger this again.