dix: assume warping on the RootWindow always happens on visible coords

If the root window borderClip region is null, the PointInWindowIsVisible()
check fails if pointer warping is attempted on the root window, making
the warping operation bail out early.

Assume coordinates always lay inside the root window for this case,
the actual position will be clamped later within screen coordinates anyway.

Signed-off-by: Carlos Garnacho <carlosg@gnome.org>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

dix/events.c

@@ -3575,7 +3575,7 @@ ProcWarpPointer(ClientPtr client)
              winX + stuff->srcX + (int) stuff->srcWidth < x) ||
             (stuff->srcHeight != 0 &&
              winY + stuff->srcY + (int) stuff->srcHeight < y) ||
-            !PointInWindowIsVisible(source, x, y))
+            (source->parent && !PointInWindowIsVisible(source, x, y)))
             return Success;
     }
     if (dest) {