Index: /trunk/arclog/arclog.pl
===================================================================
--- /trunk/arclog/arclog.pl	(revision 20223)
+++ /trunk/arclog/arclog.pl	(revision 20224)
@@ -192,4 +192,6 @@
     use warnings;
 }
+
+exit(0) unless defined $output;
 
 my $message =<<END;