[mutter] MetaWaylandPointerConstraints: Require pointer focus to enable

[Jonas Ådahl <jadahl src gnome org>]

commit 10c7035a715f1700c80e3d7b4c88ae068124daea
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Apr 1 21:10:15 2016 +0800

    MetaWaylandPointerConstraints: Require pointer focus to enable
    
    Require pointer focus to enable, otherwise we can't guarantee it has
    entered the surface, as the focus may have been given to a subsurface,
    override-redirect or other sub window covering the surface that was
    requested to have o pointer constraint.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=771050

 src/wayland/meta-wayland-pointer-constraints.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/wayland/meta-wayland-pointer-constraints.c b/src/wayland/meta-wayland-pointer-constraints.c
index 46b471d..88a3b56 100644
--- a/src/wayland/meta-wayland-pointer-constraints.c
+++ b/src/wayland/meta-wayland-pointer-constraints.c
@@ -436,6 +436,9 @@ meta_wayland_pointer_constraint_maybe_enable (MetaWaylandPointerConstraint *cons
   if (constraint->is_enabled)
     return;
 
+  if (constraint->seat->pointer->focus_surface != constraint->surface)
+    return;
+
   if (!constraint->surface->window)
     {
       /*