When a child widget of a redirected window has a background pixmap set, the
background pixmap is painted with the wrong origin (the origin of the
redirected window, rather than that of the child widget).
I've created a simple testcase that creates a 256x256 window, then creates and
sets a background pixmap for the window. The background pixmap has the same
size as the window, and is white with a black outline and an X drawn across
If you start the application without a composite manager running, the window
is rendered correctly. But as soon as you start xcompmgr (any mode), you'll
see the background redrawn with the origin of the window manager frame, rather
than that of the client window.
This bug affects multiple KDE applications, but only when composite is enabled
and a composite manager is running.
It's possible this is the same problem as reported in bug 1095.
Created attachment 652 [details]
Source file in C that when compiled and run shows the problem
An example screen shot exhibiting this problem in konsole is available at
It should look like
This seems to be what is causing graphical glitches in xfwm for me.
Fix committed. (Wish I had seen this bug before having to figure out the fix!)