[libgdata] [youtube] Fix potential unref of NULL

[Philip Withnall <pwithnall src gnome org>]

commit 9faa7ae4d66e7814399e22fd7ff8da15087e9679
Author: Philip Withnall <philip tecnocode co uk>
Date:   Mon Sep 21 08:28:40 2009 +0100

    [youtube] Fix potential unref of NULL
    
    This fixes a crash when querying for a single video without a
    GDataQuery.

 gdata/services/youtube/gdata-youtube-service.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gdata/services/youtube/gdata-youtube-service.c b/gdata/services/youtube/gdata-youtube-service.c
index df1ca37..108c453 100644
--- a/gdata/services/youtube/gdata-youtube-service.c
+++ b/gdata/services/youtube/gdata-youtube-service.c
@@ -561,7 +561,8 @@ static void
 query_single_video_async_data_free (QuerySingleVideoAsyncData *data)
 {
 	g_free (data->video_id);
-	g_object_unref (data->query);
+	if (data->query != NULL)
+		g_object_unref (data->query);
 	g_slice_free (QuerySingleVideoAsyncData, data);
 }