Creator freezes for some time after debugging JavaScript

1. Open the project qtdeclarative\examples\quick\demos\samegame\samegame.qmlproject from Qt 5.5.0's repository.
2. Start debugging.
3. In the QML app, click the "Power off" button to quit.
   Creator will not react to input for some time. This take some seconds at least, but I often get even longer freezes.

This happens with cdb as well as with gdb.

Creator should always stay responsive and not freeze for several seconds.