[glibmm] Glib::ObjectBase: Don't mention GtkObject in comments

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 8269635a223c9c3996cad58f1eafa63c03788258
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Tue Oct 10 16:00:04 2017 +0200

    Glib::ObjectBase: Don't mention GtkObject in comments
    
    Don't mention GtkObject or gtk_object_destroy() in comments. They were
    removed from gtk+ in gtk+3.

 glib/glibmm/containerhandle_shared.h |    6 ++++--
 glib/glibmm/objectbase.cc            |   12 ++++++------
 2 files changed, 10 insertions(+), 8 deletions(-)
---
diff --git a/glib/glibmm/containerhandle_shared.h b/glib/glibmm/containerhandle_shared.h
index 425734c..e8bfd7b 100644
--- a/glib/glibmm/containerhandle_shared.h
+++ b/glib/glibmm/containerhandle_shared.h
@@ -84,7 +84,8 @@ struct TypeTraits
 // be next to the objects that they use.
 #ifdef GLIBMM_CAN_USE_DYNAMIC_CAST_IN_UNUSED_TEMPLATE_WITHOUT_DEFINITION
 
-/** Partial specialization for pointers to GtkObject instances.
+/** Partial specialization for pointers to GObject instances.
+ * The C++ type is not a Glib::RefPtr<>. It can be a gtkmm widget.
  * @ingroup ContHelpers
  */
 template <class T>
@@ -116,7 +117,8 @@ struct TypeTraits<T*>
 // This confuse the SUN Forte compiler, so we ifdef it out:
 #ifdef GLIBMM_HAVE_DISAMBIGUOUS_CONST_TEMPLATE_SPECIALIZATIONS
 
-/** Partial specialization for pointers to const GtkObject instances.
+/** Partial specialization for pointers to const GObject instances.
+ * The C++ type is not a Glib::RefPtr<>. It can be a gtkmm widget.
  * @ingroup ContHelpers
  */
 template <class T>
diff --git a/glib/glibmm/objectbase.cc b/glib/glibmm/objectbase.cc
index dad5fd5..9be57e7 100644
--- a/glib/glibmm/objectbase.cc
+++ b/glib/glibmm/objectbase.cc
@@ -279,9 +279,9 @@ ObjectBase::destroy_notify_callback_(void* data)
     (void*)cppObject, (void*)cppObject->gobject_, G_OBJECT_TYPE_NAME(cppObject->gobject_));
 #endif
 
-  if (cppObject) // This will be 0 if the C++ destructor has already run.
+  if (cppObject) // This will be nullptr if the C++ destructor has already run.
   {
-    cppObject->destroy_notify_(); // Virtual - it does different things for GObject and GtkObject.
+    cppObject->destroy_notify_(); // Virtual - it does different things for Glib::ObjectBase and Gtk::Object.
   }
 }
 
@@ -290,13 +290,13 @@ ObjectBase::destroy_notify_()
 {
 // The C instance is about to be disposed, making it unusable.  Now is a
 // good time to delete the C++ wrapper of the C instance.  There is no way
-// to force the disposal of the GObject (though GtkObject  has
-// gtk_object_destroy()), So this is the *only* place where we delete the
-// C++ wrapper.
+// to force the disposal of the GObject (though Gtk::Object::destroy_notify_()
+// can call g_object_run_dispose()), so this is the *only* place where we delete
+// the C++ wrapper.
 //
 // This will only happen after the last unreference(), which will be done by
 // the RefPtr<> destructor.  There should be no way to access the wrapper or
-// the undobjecterlying instance after that, so it's OK to delete this.
+// the underlying object instance after that, so it's OK to delete this.
 
 #ifdef GLIBMM_DEBUG_REFCOUNTING
   g_warning("Glib::ObjectBase::destroy_notify_: gobject_ = %p", (void*)gobject_);