Here's a screenshot of my test case.
On the left, running on Xorg (1:7.4~5ubuntu18) on an Intel i965 (xserver-xorg-video-intel 2:2.9.1~git-0ubuntu0tormod), the squares are not shown
and on the right under Xnest, they are visible
Here's a screenshot of my test case.
On the left, running on Xorg (1:7.4~5ubuntu18) on an Intel i965 (xserver- xorg-video- intel 2:2.9.1~ git-0ubuntu0tor mod), the squares are not shown
and on the right under Xnest, they are visible