Implement core protocol backing store exclusively in terms of Composite.

Composite's automatic redirection is a more general mechanism than the
ad-hoc BS machinery, so it's much prettier to implement the one in terms
of the other.  Composite now wraps ChangeWindowAttributes and activates
automatic redirection for windows with backing store requested.  The old
backing store infrastructure is completely gutted: ABI-visible structures
retain the function pointers, but they never get called, and all the
open-coded conditionals throughout the DIX layer to implement BS are gone.

Note that this is still not a strictly complete implementation of backing
store, since Composite will throw the bits away on unmap and therefore
WhenMapped and Always hints are equivalent.

1 files changed, 0 insertions, 17 deletions

diff --git a/mi/mivaltree.c b/mi/mivaltree.c
index c999267e5..74483e354 100644
--- a/mi/mivaltree.c
+++ b/mi/mivaltree.c
@@ -513,18 +513,6 @@ miComputeClips (
 			       universe, &pParent->clipList);
     }
 
-    /*
-     * One last thing: backing storage. We have to try to save what parts of
-     * the window are about to be obscured. We can just subtract the universe
-     * from the old clipList and get the areas that were in the old but aren't
-     * in the new and, hence, are about to be obscured.
-     */
-    if (pParent->backStorage && !resized)
-    {
-	REGION_SUBTRACT( pScreen, exposed, &pParent->clipList, universe);
-	(* pScreen->SaveDoomedAreas)(pParent, exposed, dx, dy);
-    }
-    
     /* HACK ALERT - copying contents of regions, instead of regions */
     {
 	RegionRec   tmp;
@@ -816,11 +804,6 @@ miValidateTree (pParent, pChild, kind)
 			       &totalClip, &pParent->clipList);
 	/* fall through */
     case VTMap:
-	if (pParent->backStorage) {
-	    REGION_SUBTRACT( pScreen, &exposed, &pParent->clipList, &totalClip);
-	    (* pScreen->SaveDoomedAreas)(pParent, &exposed, 0, 0);
-	}
-	
 	REGION_COPY( pScreen, &pParent->clipList, &totalClip);
 	pParent->drawable.serialNumber = NEXT_SERIAL_NUMBER;
 	break;