[gtk+/wip/baedert/gtk-widget-destroy: 148/149] nativedialog: Do not ref the transient_for parent

[Timm Bäder <baedert src gnome org>]

commit 23f9a2fc33b21368843661f78bd42705dbe82ea4
Author: Timm Bäder <mail baedert org>
Date:   Wed Sep 27 20:29:07 2017 +0200

    nativedialog: Do not ref the transient_for parent
    
    gtk_window_set_transient_for does not ref its parent either. This is
    important because a child widget of the parent might be the one calling
    thsi function.

 gtk/gtknativedialog.c |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtknativedialog.c b/gtk/gtknativedialog.c
index 6e1a0ec..ff7a230 100644
--- a/gtk/gtknativedialog.c
+++ b/gtk/gtknativedialog.c
@@ -535,8 +535,20 @@ gtk_native_dialog_set_transient_for (GtkNativeDialog *self,
 
   g_return_if_fail (GTK_IS_NATIVE_DIALOG (self));
 
-  if (g_set_object (&priv->transient_for, parent))
-    g_object_notify_by_pspec (G_OBJECT (self), native_props[PROP_TRANSIENT_FOR]);
+  if (parent == priv->transient_for)
+    return;
+
+  if (parent)
+    {
+      g_signal_connect (parent, "destroy", G_CALLBACK (gtk_widget_destroyed), &priv->transient_for);
+      priv->transient_for = parent;
+    }
+  else
+    {
+      g_clear_object (&priv->transient_for);
+    }
+
+  g_object_notify_by_pspec (G_OBJECT (self), native_props[PROP_TRANSIENT_FOR]);
 }
 
 /**