[tracker] tracker-extract: don't try to insert NULL genres in gstreamer module

[Martyn James Russell <mr src gnome org>]

commit a67ddd1a9ce85586fc1315ae6d7a5b72fbe9fffa
Author: Martyn Russell <martyn imendio com>
Date:   Tue Jul 28 12:10:03 2009 +0100

    tracker-extract: don't try to insert NULL genres in gstreamer module

 src/tracker-extract/tracker-extract-gstreamer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/tracker-extract/tracker-extract-gstreamer.c b/src/tracker-extract/tracker-extract-gstreamer.c
index 3ae0fae..5de936a 100644
--- a/src/tracker-extract/tracker-extract-gstreamer.c
+++ b/src/tracker-extract/tracker-extract-gstreamer.c
@@ -527,7 +527,7 @@ extract_metadata (MetadataExtractor *extractor,
 
 			s = NULL;
 			gst_tag_list_get_string (extractor->tagcache, GST_TAG_GENRE, &s);
-			if (g_strcmp0 (s, "Unknown") != 0) {
+			if (s && strcmp (s, "Unknown") != 0) {
 				tracker_statement_list_insert (metadata, uri, NFO_PREFIX "genre", s);
 			}
 			g_free (s);