nx-X11: handle source pictures (those without a Drawable surface) gracefully.

Cherry-picked from branch 3.5.0.x.

This is basically a merge of the most current xorg-server (1.17.1) code
into nx-X11.

It makes sure that for source pictures, which do not have a drawable
surface, a filter is selected that is supported on the "main" and all
other screens.  Alternatively, if the requested filter is not available
on all screens and the picture is a source picture, this function fails
gracefully.

Additionally, the ChangePictureFilter hook is now called for non-source
pictures.

This also needs an implementation in mipict.{c,h}. The default hook does
nothing and returns a success value.

1 files changed, 6 insertions, 0 deletions

diff --git a/nx-X11/programs/Xserver/render/picturestr.h b/nx-X11/programs/Xserver/render/picturestr.h
index 4775793ab..561625766 100644
--- a/nx-X11/programs/Xserver/render/picturestr.h
+++ b/nx-X11/programs/Xserver/render/picturestr.h
@@ -344,7 +344,13 @@ typedef struct _PictureScreen {
     int				nfilterAliases;
 
     ChangePictureTransformProcPtr   ChangePictureTransform;
+
+    /**
+     * Called immediately after a picture's transform is changed through the
+     * SetPictureFilter request.  Not called for source-only pictures.
+     */
     ChangePictureFilterProcPtr	ChangePictureFilter;
+
     DestroyPictureFilterProcPtr	DestroyPictureFilter;
 
     TrapezoidsProcPtr		Trapezoids;