[libgdata] Fix a NULL pointer dereference in gdata-feed.c

[Philip Withnall <pwithnall src gnome org>]

commit a793b9eda493fe083a0968d1691fa6fa9710193b
Author: Philip Withnall <philip tecnocode co uk>
Date:   Sun Apr 19 17:17:03 2009 +0100

    Fix a NULL pointer dereference in gdata-feed.c
---
 gdata/gdata-feed.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/gdata/gdata-feed.c b/gdata/gdata-feed.c
index 7ad4bb3..00f3157 100644
--- a/gdata/gdata-feed.c
+++ b/gdata/gdata-feed.c
@@ -724,7 +724,10 @@ error:
 	g_list_free (authors);
 
 	/* Store any unhandled XML for future use */
-	feed->priv->extra_xml = g_string_free (extra_xml, FALSE);
+	if (feed != NULL)
+		feed->priv->extra_xml = g_string_free (extra_xml, FALSE);
+	else
+		g_string_free (extra_xml, 
 
 	xmlFreeDoc (doc);