[PATCH 2/2 v3] dix: fix root window background behaviour for protocol calls

[Tiago Vignatti]

Instead always paint root tiled (-retro like), protocol calls
(XSetWindowBackgroundPixmap and related) should behave accordingly when None
and ParentRelative is set as background pixmap.

It follow what the protocol states: "changing the background of a root window
to None or ParentRelative restores the default background pixmap".

Signed-off-by: Tiago Vignatti <tiago.vignatti at nokia.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at nokia.com>
---
One would want to create another patch cleaning-up and use
SetRootWindowBackground() on InitRootWindow()

changes made on v2:
- remove canDoBGNoneRoot check (kudos to Ville)
- restores always the default background pixmap (kudos to Rami)

changes made on v3:
- ParentRelative should follow None (kudos to Ville)
- BlackPixel and WhitePixel should also be caught (kudos to Ville)
- now using SetRootWindowBackground for that code

 dix/window.c |   24 ++++++++++++++++++++++--
 1 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/dix/window.c b/dix/window.c
index bfaa6f5..cba583d 100644
--- a/dix/window.c
+++ b/dix/window.c
@@ -956,6 +956,26 @@ DestroySubwindows(WindowPtr pWin, ClientPtr client)
     return Success;
 }
 
+static void
+SetRootWindowBackground(WindowPtr pWin, ScreenPtr pScreen, Mask *index2)
+{
+    /* following the protocol: "Changing the background of a root window to
+     * None or ParentRelative restores the default background pixmap" */
+    if (bgNoneRoot) {
+	pWin->backgroundState = XaceBackgroundNoneState(pWin);
+	pWin->background.pixel = pScreen->whitePixel;
+    }
+    else if (party_like_its_1989)
+	MakeRootTile(pWin);
+    else {
+	if (whiteRoot)
+	    pWin->background.pixel = pScreen->whitePixel;
+	else
+	    pWin->background.pixel = pScreen->blackPixel;
+	*index2 = CWBackPixel;
+    }
+}
+
 /*****
  *  ChangeWindowAttributes
  *   
@@ -1005,7 +1025,7 @@ ChangeWindowAttributes(WindowPtr pWin, Mask vmask, XID *vlist, ClientPtr client)
 		if (pWin->backgroundState == BackgroundPixmap)
 		    (*pScreen->DestroyPixmap)(pWin->background.pixmap);
 		if (!pWin->parent)
-		    MakeRootTile(pWin);
+		    SetRootWindowBackground(pWin, pScreen, &index2);
 		else {
 		    pWin->backgroundState = XaceBackgroundNoneState(pWin);
 		    pWin->background.pixel = pScreen->whitePixel;
@@ -1022,7 +1042,7 @@ ChangeWindowAttributes(WindowPtr pWin, Mask vmask, XID *vlist, ClientPtr client)
 		if (pWin->backgroundState == BackgroundPixmap)
 		    (*pScreen->DestroyPixmap)(pWin->background.pixmap);
 		if (!pWin->parent)
-		    MakeRootTile(pWin);
+		    SetRootWindowBackground(pWin, pScreen, &index2);
 		else
 		    pWin->backgroundState = ParentRelative;
 		borderRelative = TRUE;
-- 
1.7.0.4