Rootless: Imported changes made in xorg-server-1.2-apple branch

miext/rootless/rootlessValTree.c

@@ -482,6 +482,18 @@ RootlessComputeClips (pParent, pScreen, universe, kind, exposed)
 			       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;

miext/rootless/safeAlpha/safeAlphaPicture.c

@@ -46,6 +46,7 @@
 #include "fbpict.h"
 #include "safeAlpha.h"
 #include "rootlessCommon.h"
+# define mod(a,b)	((b) == 1 ? 0 : (a) >= 0 ? (a) % (b) : (b) - (-a) % (b))
 
 /* Optimized version of fbCompositeSolidMask_nx8x8888 */
 void
@@ -145,6 +146,16 @@ SafeAlphaComposite (CARD8           op,
                     CARD16          width,
                     CARD16          height)
 {
+  if (!pSrc) {
+    ErrorF("SafeAlphaComposite: pSrc must not be null!\n");
+    return;
+  }
+
+  if (!pDst) {
+    ErrorF("SafeAlphaComposite: pDst must not be null!\n");
+    return;
+  }
+  
   int oldDepth = pDst->pDrawable->depth;
   int oldFormat = pDst->format;
     
@@ -167,7 +178,7 @@ SafeAlphaComposite (CARD8           op,
       pDst->format = PICT_a8r8g8b8;
     }
     
-    if (pSrc && pMask && pSrc->pDrawable && pMask->pDrawable &&
+  if (pSrc->pDrawable && pMask && pMask->pDrawable &&
         !pSrc->transform && !pMask->transform &&
         !pSrc->alphaMap && !pMask->alphaMap &&
         !pMask->repeat && !pMask->componentAlpha && !pDst->alphaMap &&