[glibmm] Gio::ListModel::get_object(): Don't try to cast to Glib::Object

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 34ed6e739d97ccf03a291527063601ad18704285
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Thu Jul 15 18:50:35 2021 +0200

    Gio::ListModel::get_object(): Don't try to cast to Glib::Object
    
    Gio::ListModel::get_object() returns Glib::RefPtr<Glib::ObjectBase>.
    Don't try to dynamic_cast it to Glib::Object. It would fail if the object
    has been constructed as an interface, and e.g. has a Gio::File wrapper.
    Fixes #93

 gio/src/listmodel.hg | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gio/src/listmodel.hg b/gio/src/listmodel.hg
index 875dece9..32fb183e 100644
--- a/gio/src/listmodel.hg
+++ b/gio/src/listmodel.hg
@@ -90,6 +90,10 @@ public:
   //It doesn't do anything differently.
   _IGNORE(g_list_model_get_item)
 
+  // Don't use Glib::RefPtr<Glib::Object> Glib::wrap(GObject* object, bool take_copy).
+  // The object may be an interface object, e.g. Gio::File. Such an object can't be
+  // cast to Glib::Object. https://gitlab.gnome.org/GNOME/glibmm/-/issues/93
+#m4 
_CONVERSION(`GObject*',`Glib::RefPtr<Glib::ObjectBase>',`Glib::make_refptr_for_instance<Glib::ObjectBase>(Glib::wrap_auto($3))')
   _WRAP_METHOD(Glib::RefPtr<Glib::ObjectBase> get_object(guint position), g_list_model_get_object, newin 
"2,50")
   _WRAP_METHOD(Glib::RefPtr<const Glib::ObjectBase> get_object(guint position) const, 
g_list_model_get_object, constversion, newin "2,50")