[mutter] selection: Unref selection owners on dispose

[Robert Mader <rmader src gnome org>]

commit 35316a034faa9013315d29101a823d33093f6162
Author: Sebastian Keller <skeller gnome org>
Date:   Thu Jan 30 09:52:08 2020 +0100

    selection: Unref selection owners on dispose
    
    Selection owners are set using g_set_object, which adds a reference to
    the owner, which then never was removed on shutdown.
    
    Fixes parts of https://gitlab.gnome.org/GNOME/mutter/issues/1006
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/1001

 src/core/meta-selection.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
---
diff --git a/src/core/meta-selection.c b/src/core/meta-selection.c
index 504d322e7..e0ff9f4b1 100644
--- a/src/core/meta-selection.c
+++ b/src/core/meta-selection.c
@@ -50,9 +50,27 @@ static guint signals[N_SIGNALS] = { 0 };
 
 G_DEFINE_TYPE (MetaSelection, meta_selection, G_TYPE_OBJECT)
 
+static void
+meta_selection_dispose (GObject *object)
+{
+  MetaSelection *selection = META_SELECTION (object);
+  guint i;
+
+  for (i = 0; i < META_N_SELECTION_TYPES; i++)
+    {
+      g_clear_object (&selection->owners[i]);
+    }
+
+  G_OBJECT_CLASS (meta_selection_parent_class)->dispose (object);
+}
+
 static void
 meta_selection_class_init (MetaSelectionClass *klass)
 {
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = meta_selection_dispose;
+
   signals[OWNER_CHANGED] =
     g_signal_new ("owner-changed",
                   G_TYPE_FROM_CLASS (klass),