[glib] gasyncresult: document that NULL GAsyncReadyCallback is allowed

[Dan Winship <danw src gnome org>]

commit 2080bb1dc0bd6e7fb137df0e28796cdb2024645c
Author: Dan Winship <danw gnome org>
Date:   Wed Jun 29 08:29:16 2011 -0400

    gasyncresult: document that NULL GAsyncReadyCallback is allowed
    
    https://bugzilla.gnome.org/show_bug.cgi?id=653484

 gio/gasyncresult.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)
---
diff --git a/gio/gasyncresult.c b/gio/gasyncresult.c
index aec48d6..b23b456 100644
--- a/gio/gasyncresult.c
+++ b/gio/gasyncresult.c
@@ -51,9 +51,11 @@
  * "enumerate children" operation). If the result or error status of the
  * operation is not needed, there is no need to call the "_finish()"
  * function; GIO will take care of cleaning up the result and error
- * information after the #GAsyncReadyCallback returns. Applications may
- * also take a reference to the #GAsyncResult and call "_finish()"
- * later; however, the "_finish()" function may be called at most once.
+ * information after the #GAsyncReadyCallback returns. You can pass
+ * %NULL for the #GAsyncReadyCallback if you don't need to take any
+ * action at all after the operation completes. Applications may also
+ * take a reference to the #GAsyncResult and call "_finish()" later;
+ * however, the "_finish()" function may be called at most once.
  *
  * Example of a typical asynchronous operation flow:
  * |[