From b69e6165136ff76ba4649bb9d11906fef27b78bc Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@koto.keithp.com>
Date: Sat, 1 Sep 2007 21:14:22 -0700
Subject: [PATCH] [COMPOSITE] Composite used for pixmap population on redirect.
 (Bug #7447)

compNewPixmap copies bits from the parent window to the redirected child
pixmap to populate the pixmap with reasonable data. It cannot always use
CopyArea as that only works across matching depths. Use Composite when
the depths do not match.
(cherry picked from commit f98dfec79dadb70fa7bba84e7335f92b3a73dc02)
---
 composite/compalloc.c  | 73 +++++++++++++++++++++++++++++++-----------
 composite/compint.h    |  3 ++
 composite/compwindow.c |  2 +-
 3 files changed, 59 insertions(+), 19 deletions(-)

diff --git a/composite/compalloc.c b/composite/compalloc.c
index f555411bf..006e80840 100644
--- a/composite/compalloc.c
+++ b/composite/compalloc.c
@@ -461,7 +461,6 @@ compNewPixmap (WindowPtr pWin, int x, int y, int w, int h)
     ScreenPtr	    pScreen = pWin->drawable.pScreen;
     WindowPtr	    pParent = pWin->parent;
     PixmapPtr	    pPixmap;
-    GCPtr	    pGC;
 
     pPixmap = (*pScreen->CreatePixmap) (pScreen, w, h, pWin->drawable.depth);
 
@@ -471,25 +470,63 @@ compNewPixmap (WindowPtr pWin, int x, int y, int w, int h)
     pPixmap->screen_x = x;
     pPixmap->screen_y = y;
     
-    pGC = GetScratchGC (pWin->drawable.depth, pScreen);
-    
-    /*
-     * Copy bits from the parent into the new pixmap so that it will
-     * have "reasonable" contents in case for background None areas.
-     */
-    if (pGC)
+    if (pParent->drawable.depth == pWin->drawable.depth)
     {
-	XID val = IncludeInferiors;
+	GCPtr	pGC = GetScratchGC (pWin->drawable.depth, pScreen);
 	
-	ValidateGC(&pPixmap->drawable, pGC);
-	dixChangeGC (serverClient, pGC, GCSubwindowMode, &val, NULL);
-	(*pGC->ops->CopyArea) (&pParent->drawable,
-			       &pPixmap->drawable,
-			       pGC,
-			       x - pParent->drawable.x,
-			       y - pParent->drawable.y,
-			       w, h, 0, 0);
-	FreeScratchGC (pGC);
+	/*
+	 * Copy bits from the parent into the new pixmap so that it will
+	 * have "reasonable" contents in case for background None areas.
+	 */
+	if (pGC)
+	{
+	    XID val = IncludeInferiors;
+	    
+	    ValidateGC(&pPixmap->drawable, pGC);
+	    dixChangeGC (serverClient, pGC, GCSubwindowMode, &val, NULL);
+	    (*pGC->ops->CopyArea) (&pParent->drawable,
+				   &pPixmap->drawable,
+				   pGC,
+				   x - pParent->drawable.x,
+				   y - pParent->drawable.y,
+				   w, h, 0, 0);
+	    FreeScratchGC (pGC);
+	}
+    }
+    else
+    {
+	PictFormatPtr	pSrcFormat = compWindowFormat (pParent);
+	PictFormatPtr	pDstFormat = compWindowFormat (pWin);
+	XID		inferiors = IncludeInferiors;
+	int		error;
+
+	PicturePtr	pSrcPicture = CreatePicture (None,
+						     &pParent->drawable,
+						     pSrcFormat,
+						     CPSubwindowMode,
+						     &inferiors,
+						     serverClient, &error);
+						    
+	PicturePtr	pDstPicture = CreatePicture (None,
+						     &pPixmap->drawable,
+						     pDstFormat,
+						     0, 0,
+						     serverClient, &error);
+
+	if (pSrcPicture && pDstPicture)
+	{
+	    CompositePicture (PictOpSrc,
+			      pSrcPicture,
+			      NULL,
+			      pDstPicture,
+			      x - pParent->drawable.x,
+			      y - pParent->drawable.y,
+			      0, 0, 0, 0, w, h);
+	}
+	if (pSrcPicture)
+	    FreePicture (pSrcPicture, 0);
+	if (pDstPicture)
+	    FreePicture (pDstPicture, 0);
     }
     return pPixmap;
 }
diff --git a/composite/compint.h b/composite/compint.h
index 2c4d5c002..a5ed24e3a 100644
--- a/composite/compint.h
+++ b/composite/compint.h
@@ -232,6 +232,9 @@ compCheckTree (ScreenPtr pScreen);
 #define compCheckTree(s)
 #endif
 
+PictFormatPtr
+compWindowFormat (WindowPtr pWin);
+
 void
 compSetPixmap (WindowPtr pWin, PixmapPtr pPixmap);
 
diff --git a/composite/compwindow.c b/composite/compwindow.c
index a4c4e6f32..bfd29460b 100644
--- a/composite/compwindow.c
+++ b/composite/compwindow.c
@@ -685,7 +685,7 @@ compGetWindowVisual (WindowPtr pWin)
     return 0;
 }
 
-static PictFormatPtr
+PictFormatPtr
 compWindowFormat (WindowPtr pWin)
 {
     ScreenPtr	pScreen = pWin->drawable.pScreen;