[Xorg] Is there a way for a program to detect if composite is enabled

[Kristof Vansant]

I was looking at following patch for gaim and I thought there should be
a better way:

Summary: (?)
Disable tooltip shadows when X composite extension installed
The drop shadows on the buddy list tooltips interfere
with the real shadows being provided by the new X
composite extension. Eventually the real shadows from
a composition manager can probably replace any shadows
in gaim. But for now this patch detects if the
composition extension is installed at configure time
and if so it disables the drop shadows.

While having the composite extension installed does not
necessarily mean it's being used, this is the best we
can do without runtime checks. It already seems silly
enough to be checking for something we don't need.

https://sourceforge.net/tracker/index.php?func=detail&aid=1010290&group_id=235&atid=300235
-- 
lupusBE (Kristof Vansant Belgium