xorg-x11-server/u_fb-Correctly-implement-CopyArea-when-using-a-window-with-depth-32-and-24bpp.patch

From patchwork Fri Jun  6 11:52:13 2014
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Subject: fb: Correctly implement CopyArea when using a window with depth 32
 and 24bpp.
From: Robert Ancell <robert.ancell@canonical.com>
X-Patchwork-Id: 27263
Message-Id: <1402055533-9866-1-git-send-email-robert.ancell@canonical.com>
To: xorg-devel@lists.x.org
Cc: Robert Ancell <robert.ancell@canonical.com>
Date: Fri,  6 Jun 2014 23:52:13 +1200

When using the fb backend at 24bpp it allows a visual with 32 bit depth.
When using CopyArea from a 32bpp pixmap to a window with a 32 bit depth it would
read the ARGB as RGB.

Fix is to correctly ignore the alpha channel in the pixmap when copying.

---
fb/fbcopy.c | 10 +++++++++-
 fb/fbcopy.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/fb/fbcopy.c
+++ b/fb/fbcopy.c
@@ -242,8 +242,16 @@ fbCopyArea(DrawablePtr pSrcDrawable,
            int xIn, int yIn, int widthSrc, int heightSrc, int xOut, int yOut)
 {
     miCopyProc copy;
+    int src_bpp, dst_bpp;
 
-    if (pSrcDrawable->bitsPerPixel != pDstDrawable->bitsPerPixel)
+    src_bpp = pSrcDrawable->bitsPerPixel;
+    if (src_bpp < pSrcDrawable->depth)
+        src_bpp = BitsPerPixel (pSrcDrawable->depth);
+    dst_bpp = pDstDrawable->bitsPerPixel;
+    if (dst_bpp < pDstDrawable->depth)
+        dst_bpp = BitsPerPixel (pDstDrawable->depth);
+
+    if (src_bpp != dst_bpp)
         copy = fb24_32CopyMtoN;
     else
         copy = fbCopyNtoN;