[glib] GBusNameVanishedCallback: document NULL connection

[Ryan Lortie <ryanl src gnome org>]

commit 654bfcb7ce3b99d6b71ae86f1e0aee33056f70b1
Author: Ryan Lortie <desrt desrt ca>
Date:   Tue Oct 16 12:29:22 2012 -0400

    GBusNameVanishedCallback: document NULL connection
    
    @connection can be NULL for this callback.  Document this possibility
    and describe the circumstances.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=686231

 gio/gdbusnamewatching.h |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/gio/gdbusnamewatching.h b/gio/gdbusnamewatching.h
index 3e3f75a..a2bb6dc 100644
--- a/gio/gdbusnamewatching.h
+++ b/gio/gdbusnamewatching.h
@@ -49,12 +49,17 @@ typedef void (*GBusNameAppearedCallback) (GDBusConnection *connection,
 
 /**
  * GBusNameVanishedCallback:
- * @connection: The #GDBusConnection the name is being watched on.
+ * @connection: The #GDBusConnection the name is being watched on, or
+ *     %NULL.
  * @name: The name being watched.
  * @user_data: User data passed to g_bus_watch_name().
  *
  * Invoked when the name being watched is known not to have to have a owner.
  *
+ * This is also invoked when the #GDBusConection on which the watch was
+ * established has been closed.  In that case, @connection will be
+ * %NULL.
+ *
  * Since: 2.26
  */
 typedef void (*GBusNameVanishedCallback) (GDBusConnection *connection,