Run an application, e.g. mainwindow from qtbase examples.
Rotate the screen twice:
> xrandr --output LVDS1 --rotate left
> xrandr --output LVDS1 --rotate normal

The application will segfault after clicking the mouse on it's window.
It's also can be reproduced by changing the screen mode twice.

The main condition for reproducing this bug is that a monitor is disabled
for a moment in the middle of changing it's configuration.