[glib] gio: mark the GAsyncResult source_object as nullable

[Philip Withnall <pwithnall src gnome org>]

commit ca4fe5942afa5d24f2c99f12d41598cf04b7718f
Author: Evan Nemerson <evan nemerson com>
Date:   Sun Nov 16 12:16:23 2014 -0800

    gio: mark the GAsyncResult source_object as nullable
    
    https://bugzilla.gnome.org/show_bug.cgi?id=740223

 gio/gasyncresult.c |    4 ++--
 gio/giotypes.h     |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/gio/gasyncresult.c b/gio/gasyncresult.c
index fafda9a..cffe889 100644
--- a/gio/gasyncresult.c
+++ b/gio/gasyncresult.c
@@ -147,8 +147,8 @@ g_async_result_get_user_data (GAsyncResult *res)
  *
  * Gets the source object from a #GAsyncResult.
  *
- * Returns: (transfer full): a new reference to the source object for the @res,
- *    or %NULL if there is none.
+ * Returns: (transfer full) (nullable): a new reference to the source
+ *    object for the @res, or %NULL if there is none.
  */
 GObject *
 g_async_result_get_source_object (GAsyncResult *res)
diff --git a/gio/giotypes.h b/gio/giotypes.h
index 67c9cc7..11e0589 100644
--- a/gio/giotypes.h
+++ b/gio/giotypes.h
@@ -259,7 +259,7 @@ typedef struct _GVolumeMonitor                GVolumeMonitor;
 
 /**
  * GAsyncReadyCallback:
- * @source_object: the object the asynchronous operation was started with.
+ * @source_object: (nullable): the object the asynchronous operation was started with.
  * @res: a #GAsyncResult.
  * @user_data: user data passed to the callback.
  *