[gtk+] GtkListBox: Allow a NULL callback in bind_model

[Timm Bäder <baedert src gnome org>]

commit 1405bcb32d4e63e5f641eb8f54bafec2581520e0
Author: Timm Bäder <mail baedert org>
Date:   Tue Sep 1 10:41:42 2015 +0200

    GtkListBox: Allow a NULL callback in bind_model
    
    When unsetting the bound model, one can pass NULL, but in that case the
    create_func parameter should also be NULL.

 gtk/gtklistbox.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtklistbox.c b/gtk/gtklistbox.c
index fd91acf..01a0f4d 100644
--- a/gtk/gtklistbox.c
+++ b/gtk/gtklistbox.c
@@ -3752,8 +3752,9 @@ gtk_list_box_check_model_compat (GtkListBox *box)
 /**
  * gtk_list_box_bind_model:
  * @box: a #GtkListBox
- * @model: (allow-none): the #GListModel to be bound to @box
- * @create_widget_func: a function that creates widgets for items
+ * @model: (nullable): the #GListModel to be bound to @box
+ * @create_widget_func: (nullable): a function that creates widgets for items
+ *   or %NULL in case you also passed %NULL as @model
  * @user_data: user data passed to @create_widget_func
  * @user_data_free_func: function for freeing @user_data
  *