A couple of composite fixes from Owen Taylor

[Owen Taylor]

On Fri, 2008-09-19 at 09:06 -0700, Keith Packard wrote:
> On Fri, 2008-09-19 at 17:11 +0200, Maarten Maathuis wrote:
> 
> > Is there a reason why you didn't commit these patches?
> 
> Owen hasn't tested the second patch yet. Also, it's nice to see if
> anyone has comments on the patch before they hit master.

I've tested both patches and they work well as far as I can tell.

(Of course, proving that they don't cause obscure problems elsewhere is
a lot harder than proving that they fix the problems they were designed
to fix.)

Also, they make sense to me as patches. 

I guess I might quibble with the comment in the second one which makes
it sounds like this has to do with exotic guffaw scrolling manipulations
or something.

 /* No matter what happened to the parent window bits because of window
  * and bit gravity, the bits of redirected children are not affected
  * so no exposures are needed
  */

?

- Owen