examples: Check for NULL cursors in class-signal example

It is unlikely to receive errors on queries there, but still this is an
example, so better be correct there.

Coverity ID: 1188420

1 files changed, 9 insertions, 0 deletions

diff --git a/examples/libtracker-sparql/class-signal.c b/examples/libtracker-sparql/class-signal.c
index 3ba2ab3f4..63fce7be6 100644
--- a/examples/libtracker-sparql/class-signal.c
+++ b/examples/libtracker-sparql/class-signal.c
@@ -33,14 +33,23 @@ handle_statement (gint subject, gint predicate)
 	                         subject, predicate);
 	cursor = tracker_sparql_connection_query (con, query, NULL, NULL);
 	g_free (query);
+
+	if (!cursor)
+		return;
+
 	tracker_sparql_cursor_next (cursor, NULL, NULL);
 	pred = g_strdup (tracker_sparql_cursor_get_string (cursor, 1, NULL));
 	query = g_strdup_printf ("SELECT ?t { <%s> <%s> ?t }",
 	                         tracker_sparql_cursor_get_string (cursor, 0, NULL),
 	                         pred);
 	g_object_unref (cursor);
+
 	cursor = tracker_sparql_connection_query (con, query, NULL, NULL);
 	g_free (query);
+
+	if (!cursor)
+		return;
+
 	while (tracker_sparql_cursor_next (cursor, NULL, NULL))
 		g_print ("\t%s = %s\n", pred, tracker_sparql_cursor_get_string (cursor, 0, NULL));
 	g_print ("\n");