[gtk+/places-sidebar] Allow not setting a changed callback on GtkBookmarksManager

[Federico Mena Quintero <federico src gnome org>]

commit eecda25d64686031aa384705c82da421d5d14bdc
Author: Federico Mena Quintero <federico gnome org>
Date:   Wed Dec 5 18:03:54 2012 -0600

    Allow not setting a changed callback on GtkBookmarksManager

 gtk/gtkbookmarksmanager.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkbookmarksmanager.c b/gtk/gtkbookmarksmanager.c
index 4341c38..5beb722 100644
--- a/gtk/gtkbookmarksmanager.c
+++ b/gtk/gtkbookmarksmanager.c
@@ -152,7 +152,8 @@ save_bookmarks (GFile  *bookmarks_file,
 static void
 notify_changed (GtkBookmarksManager *manager)
 {
-  manager->changed_func (manager->changed_func_data);
+  if (manager->changed_func)
+    manager->changed_func (manager->changed_func_data);
 }
 
 static void
@@ -193,8 +194,6 @@ _gtk_bookmarks_manager_new (GtkBookmarksChangedFunc changed_func, gpointer chang
   GFile *bookmarks_file;
   GError *error;
 
-  g_return_val_if_fail (changed_func != NULL, NULL);
-
   manager = g_new0 (GtkBookmarksManager, 1);
 
   manager->changed_func = changed_func;