[mutter] group: Select for property notifies on group leaders

[Jasper St. Pierre <jstpierre src gnome org>]

commit aea71fbd0119d31a69787985beb77bfac8842e93
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Sat Jun 27 00:52:25 2015 -0700

    group: Select for property notifies on group leaders

 src/x11/group.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/src/x11/group.c b/src/x11/group.c
index a09b980..9e5b576 100644
--- a/src/x11/group.c
+++ b/src/x11/group.c
@@ -50,6 +50,11 @@ meta_group_new (MetaDisplay *display,
   group->group_leader = group_leader;
   group->refcount = 1; /* owned by caller, hash table has only weak ref */
 
+  XWindowAttributes attrs;
+  XGetWindowAttributes (display->xdisplay, group_leader, &attrs);
+  XSelectInput (display->xdisplay, group_leader,
+                attrs.your_event_mask | PropertyChangeMask);
+
   if (display->groups_by_leader == NULL)
     display->groups_by_leader = g_hash_table_new (meta_unsigned_long_hash,
                                                   meta_unsigned_long_equal);