[libwnck/wip/muktupavels/issue-141] class-group: add a weak reference callback to window

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 0ceae2509eb6b04310533801ae599338939add89
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Fri Aug 2 20:43:50 2019 +0300

    class-group: add a weak reference callback to window
    
    When wnck_shutdown is called all windows are destroyed, but nothing
    removes signal handlers from hash tables. When class group is destroyed
    it will try to remove signal handlers from already destroyed windows.
    
    Use weak reference callback to remove obsolete signal handlers from
    hash tables.
    
    https://gitlab.gnome.org/GNOME/libwnck/issues/141

 libwnck/class-group.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
---
diff --git a/libwnck/class-group.c b/libwnck/class-group.c
index 2a274e2..4b658d8 100644
--- a/libwnck/class-group.c
+++ b/libwnck/class-group.c
@@ -496,6 +496,20 @@ update_class_group_name (WnckWindow     *window,
   set_name (class_group);
 }
 
+static void
+window_weak_notify_cb (gpointer  data,
+                       GObject  *where_the_window_was)
+{
+  WnckClassGroup *class_group;
+  WnckClassGroupPrivate *priv;
+
+  class_group = WNCK_CLASS_GROUP (data);
+  priv = class_group->priv;
+
+  g_hash_table_remove (priv->window_icon_handlers, where_the_window_was);
+  g_hash_table_remove (priv->window_name_handlers, where_the_window_was);
+}
+
 /**
  * _wnck_class_group_add_window:
  * @class_group: a #WnckClassGroup.
@@ -534,6 +548,8 @@ _wnck_class_group_add_window (WnckClassGroup *class_group,
                        window,
                        (gpointer) signal_id);
 
+  g_object_weak_ref (G_OBJECT (window), window_weak_notify_cb, class_group);
+
   set_name (class_group);
   set_icon (class_group);