v4.9-rc3: graphical artefacts in X

Hi!

With v4.9, if I maximize "nowcast -x" application, I get broken display (as if someone split the window into rectangles and shuffled them a bit). Switching virtual desktops either fixes it or breaks it, depending in how fast I switch. (Yes, strange).

pavel@amd:~$ lspci | grep VGA 00:02.0 VGA compatible controller: Intel Corporation 4 Series Chipset Integrated Graphics Controller (rev 03) pavel@amd:~$

Recompile, reboot, and graphics is okay.

(On thinkpad x60, I have seen other strange problems, mostly when I maximize video, but not as easily reproducible).

Pavel