[tracker] tracker-extract: ensure there is something on the sparql builders.

[Carlos Garnacho <carlosg src gnome org>]

commit 48c112513dec2209258420434f2a89f1802993ce
Author: Carlos Garnacho <carlos lanedo com>
Date:   Fri Feb 5 11:59:37 2010 +0100

    tracker-extract: ensure there is something on the sparql builders.
    
    when called on the command line, sparql builders length wasn't being
    checked.

 src/tracker-extract/tracker-extract.c |   19 +++++++++++++++++--
 1 files changed, 17 insertions(+), 2 deletions(-)
---
diff --git a/src/tracker-extract/tracker-extract.c b/src/tracker-extract/tracker-extract.c
index 792a1fc..05fdaf6 100644
--- a/src/tracker-extract/tracker-extract.c
+++ b/src/tracker-extract/tracker-extract.c
@@ -438,12 +438,27 @@ tracker_extract_get_metadata_by_cmdline (TrackerExtract *object,
 	if (get_file_metadata (object, request_id,
 			       NULL, uri, mime,
 			       &preupdate, &statements)) {
+		gchar *preupdate_str, *statements_str;
+
+		preupdate_str = statements_str = NULL;
+
+		if (tracker_sparql_builder_get_length (statements) > 0) {
+			statements_str = tracker_sparql_builder_get_result (statements);
+		}
+
+		if (tracker_sparql_builder_get_length (preupdate) > 0) {
+			preupdate_str = tracker_sparql_builder_get_result (preupdate);
+		}
+
 		tracker_dbus_request_info (request_id, NULL, "%s",
-					   tracker_sparql_builder_get_result (preupdate));
+					   preupdate_str ? preupdate_str : "");
 		tracker_dbus_request_info (request_id, NULL, "%s",
-					   tracker_sparql_builder_get_result (statements));
+					   statements_str ? statements_str : "");
+
 		g_object_unref (statements);
 		g_object_unref (preupdate);
+		g_free (statements_str);
+		g_free (preupdate_str);
 	}
 
 	tracker_dbus_request_success (request_id, NULL);