[gtk+] gtkprintbackendcups: Fix a crash in gtk_print_backend_cups_finalize()

[Carlos Garcia Campos <carlosgc src gnome org>]

commit b29cd63c381a1f10356e914dfe55b9f47ed05dab
Author: Carlos Garcia Campos <cgarcia igalia com>
Date:   Mon Mar 25 12:09:52 2013 +0100

    gtkprintbackendcups: Fix a crash in gtk_print_backend_cups_finalize()
    
    If GtkPrintBackendCups is finalized and cups_get_printer_list hasn't
    been called, g_object_unref is called for the GDBusConnection pointer
    that is NULL. Use g_clear_object() instead.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=696546

 modules/printbackends/cups/gtkprintbackendcups.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/modules/printbackends/cups/gtkprintbackendcups.c 
b/modules/printbackends/cups/gtkprintbackendcups.c
index 64b92bc..45aa007 100644
--- a/modules/printbackends/cups/gtkprintbackendcups.c
+++ b/modules/printbackends/cups/gtkprintbackendcups.c
@@ -852,7 +852,7 @@ gtk_print_backend_cups_finalize (GObject *object)
 
   g_clear_object (&backend_cups->avahi_cancellable);
   g_clear_pointer (&backend_cups->avahi_default_printer, g_free);
-  g_object_unref (backend_cups->dbus_connection);
+  g_clear_object (&backend_cups->dbus_connection);
 #endif
 
   backend_parent_class->finalize (object);