compilation fix for older glib versions after r56345

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@56349 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/private.h

@@ -105,6 +105,12 @@ void gtk_window_set_policy (GtkWindow *window,
 } // extern "C"
 
 
+// some newer functions not available in older versions of GTK+:
+#if !GTK_CHECK_VERSION(2,9,0)
+#define g_object_ref_sink(x) gtk_object_sink(GTK_OBJECT(x))
+#endif
+
+
 // ----------------------------------------------------------------------------
 // various private helper functions
 // ----------------------------------------------------------------------------

src/gtk/artgtk.cpp

@@ -23,6 +23,7 @@
 #if !defined(__WXUNIVERSAL__)
 
 #include "wx/artprov.h"
+#include "wx/gtk/private.h"
 
 #ifndef WX_PRECOMP
     #include "wx/module.h"