Index: libjack/client.c
===================================================================
--- libjack/client.c	(Revision 4066)
+++ libjack/client.c	(Arbeitskopie)
@@ -2796,11 +2796,6 @@
 
 	matching_ports[match_cnt] = 0;
 
-	if (match_cnt == 0) {
-		free (matching_ports);
-		matching_ports = 0;
-	}
-
 	return matching_ports;
 }
 
Index: tools/lsp.c
===================================================================
--- tools/lsp.c	(Revision 4066)
+++ tools/lsp.c	(Arbeitskopie)
@@ -135,7 +135,10 @@
 		return 1;
 	}
 
-	ports = jack_get_ports (client, NULL, NULL, 0);
+ 	if ((ports = jack_get_ports(client, NULL, NULL, 0)) == NULL) {
+     fprintf (stderr, "jack_get_ports() returned NULL.");
+     goto cleanup;
+   }
 
 	for (i = 0; ports[i]; ++i) {
 		// skip over any that don't match ALL of the strings presented at command line
@@ -211,6 +214,8 @@
 			}
 		}
 	}
+
+cleanup:
 	jack_client_close (client);
 	exit (0);
 }
Index: jack/jack.h
===================================================================
--- jack/jack.h	(Revision 4066)
+++ jack/jack.h	(Arbeitskopie)
@@ -869,8 +869,8 @@
  * If zero, no selection based on flags will be carried out.
  *
  * @return a NULL-terminated array of ports that match the specified
- * arguments.  The caller is responsible for calling jack_free(3) any
- * non-NULL returned value.
+ * arguments, or NULL on error. The caller is responsible for calling 
+ * jack_free(3) any non-NULL returned value.
  *
  * @see jack_port_name_size(), jack_port_type_size()
  */