Window height resize is jerky, judders

Using Debian Jessie with latest packages, when resizing some of the QT examples the window is very jerky. On a resize QT seems to paint the window background black or gray, copy the old window in to the larger one before triggering a window resize and refreshing the whole window. This happens under both XFCE and Gnome, on Intel GPU and Radeon GPU.

It seems to affect some examples more than others. It is noticeable in /usr/lib/x86_64-linux-gnu/qt5/examples/quick/dialogs/systemdialogs from qtquickcontrols5-examples. It is also very apparent in the hellogl2 examples. It also seems to affect hellogl example from qt4-demos.

Screenshots taken while resizing: http://imgur.com/a/5AP01

I do not know if this is just the normal behaviour for some QT apps, but I would expect window resizing to be smooth and not jerky and juddery.